@STRING{PROC = {Proceedings of the }}

@INPROCEEDINGS{Adamoli2010,
  author = {Andrea Adamoli and Matthias Hauswirth},
  title = {Trevis: A context tree visualization and analysis framework and its
	use for classifying performance failure reports},
  pages = {73--82},
  abstract = {When developers profile their applications to identify performance
	problems, they normally use profilers producing calling context trees.
	A calling context tree (CCT) represents the caller-callee relationships
	of a program. A dynamically collected CCT provides method coverage
	information. The CCTs produced by profilers also include method hotness
	information. Trevis, our context tree visualization and analysis
	framework, allows users to visualize, compare, cluster, and intersect
	CCTs produced by profilers. We evaluate Trevis in the context of
	a novel profiling tool called FlyBy. FlyBy runs transparently on
	an end-user's computer and continuously samples the applications'
	call stack. When the user perceives the application as sluggish,
	she presses a "Was Slow!" button to tell FlyBy to file a performance
	failure report. The report contains the CCT based on the call stack
	samples FlyBy gathered over the last few seconds before the user
	pressed the button. We show how Trevis allows us to visualize and
	classify FlyBy bug reports.},
  crossref = {SOFTVIS2010},
  doi = {10.1145/1879211.1879224}
}

@INPROCEEDINGS{Ahmed2007,
  author = {Adel Ahmed and Seok-Hee Hong},
  title = {Navigation techniques for {2.5D} graph layout},
  pages = {81--84},
  abstract = {In this paper, we consider the problem of navigating graphs drawn
	in 2.5 dimensions. First, we define criteria for good navigation
	and then present various methods to satisfy some of the criteria.
	In particular, we design and implement methods for trees, clustered
	graphs and hierarchical graphs drawn in 2.5 dimensions.},
  crossref = {APVIS2007},
  doi = {10.1109/APVIS.2007.329279}
}

@INPROCEEDINGS{Andrews2002a,
  author = {Keith Andrews},
  title = {Visual Exploration of Large Hierarchies with Information Pyramids},
  pages = {793--798},
  abstract = {Information pyramids compactly visualise large hierarchical structures
	in three dimensions using pyramid-like structures, which grow upwards
	as the hierarchy deepens. A plateau represents the root of the tree;
	other, smaller plateaus arranged on top of it represent its subtrees.
	Separate glyphs are used to represent leaf nodes such as files or
	documents and navigational facilities are provided for interactive
	exploration. Two generations of information pyramids prototype are
	described and discussed.},
  crossref = {IV2002},
  doi = {10.1109/IV.2002.1028871}
}

@INPROCEEDINGS{Andrews1998,
  author = {Keith Andrews and Helmut Heidegger},
  title = {Information Slices: Visualising and Exploring Large Hierarchies using
	Cascading, Semi-Circular Discs},
  pages = {9--12},
  note = {Late Breaking Hot Topic Paper},
  abstract = {This paper presents work in progress on a new technique for visualising
	and manipulating large hierarchies. The information slices approach
	compactly visualises hierarchical structures using a series of semi-circular
	discs. The technique is described in the context of our early experience
	with a prototype file system visualiser based on information slices.},
  crossref = {INFOVIS1998}
}

@INPROCEEDINGS{Andrews2003,
  author = {Keith Andrews and Wolfgang Kienreich and Vedran Sabol and Michael
	Granitzer},
  title = {Visualising Large Hierarchically Structured Document Repositories
	with {InfoSky}},
  pages = {70--71},
  abstract = {InfoSky is an interactive system for the exploration of large, hierarchically
	structured document collections. InfoSky employs a planar graphical
	representation with variable magnification like a real-world telescope.
	The hierarchical structure is reflected using recursive subdivision
	into Voronoi polygons. At each level of the hierarchy documents and
	subcollections are positioned according to the similarity of their
	content using a force-directed placement technique. Documents are
	assumed to have significant textual content, which can be extracted
	with specialised tools. The hierarchical structure is exploited for
	greater performance. Force-directed placement is applied recursively
	at each level on the objects at that level rather than on the whole
	corpus.},
  crossref = {INFOVISposter2003},
  url = {http://conferences.computer.org/infovis/files/compendium2003.pdf}
}

@INPROCEEDINGS{Andrews2004,
  author = {Keith Andrews and Wolfgang Kienreich and Vedran Sabol and Michael
	Granitzer},
  title = {The visualisation of large hierarchical document spaces with {InfoSky}},
  abstract = {It is no longer unusual for large document collections to contain
	many millions of documents. In order to manage this size of repository,
	it is often essential to structure the repository according to a
	thematic classification hierarchy. InfoSky is a system enabling users
	to explore such large, hierarchically structured document collections.
	Similar to a real-world telescope, InfoSky employs a planar graphical
	representation with variable magnification. The hierarchical structure
	is represented by recursive Voronoi subdivision of the available
	space. At each level, larger subcollections are assigned more space
	and related subcollections gravitate towards one another. Individual
	documents at each level of the hierarchy are represented by stars
	placed according to their similarity. Finally, InfoSky extracts and
	displays descriptors describing the essential theme of each subcollection
	at each level of the hierarchy.},
  crossref = {CODATA2004},
  url = {http://dcgi.felk.cvut.cz/cgg/infoviz04/papers/andrews.pdf}
}

@INPROCEEDINGS{Andrews1997,
  author = {Keith Andrews and Josef Wolte and Michael Pichler},
  title = {Information Pyramids\texttrademark: A New Approach to Visualising
	Large Hierarchies},
  pages = {49--52},
  note = {Late Breaking Hot Topic Paper},
  abstract = {This paper presents work in progress on a new technique for visualising
	and manipulating large hierarchies. The Information Pyramids approach
	compactly visualises hierarchical structures in three dimensions
	using pyramid-like structures, which grow upwards as the hierarchy
	is descended. The technique is described in the context of our early
	experience with a prototype file system visualiser based on Information
	Pyramids.},
  crossref = {VIS1997}
}

@INPROCEEDINGS{Appert2006,
  author = {Caroline Appert and Jean-Daniel Fekete},
  title = {{ControlTree}: Navigating and Selecting in a Large Tree},
  pages = {47--48},
  abstract = {We introduce ControlTree, a novel interface using crossing interaction
	to navigate and select nodes in a large tree. ControlTree combines
	an optimized dynamic layout with interaction features to quickly
	reach a node in a node-link tree representation.},
  crossref = {UISTdemos2006},
  url = {http://www.acm.org/uist/archive/adjunct/2006/pdf/demos/p47-appert.pdf}
}

@INPROCEEDINGS{Appert2007,
  author = {Caroline Appert and Jean-Daniel Fekete},
  title = {Naviguer dans des grands arbres avec {ControlTree}},
  pages = {139--142},
  abstract = {This article presents ControlTree, a relevant technique to select
	a node is a very large node-link representation using a continuous
	interaction. The node-link representation is dynamic and driven by
	the cursor location to optimize screen space and to ease the selections.
	ControlTree uses a snapping mechanism and adapts the OrthoZoom technique
	to offer an alternative to common "point-and-click" techniques. We
	also present a preliminary theoretical evaluation showing that ControlTree
	is a promising technique.},
  crossref = {IHM2007},
  doi = {10.1145/1541436.1541463}
}

@INPROCEEDINGS{Bachmaier2008,
  author = {Christian Bachmaier and Franz J. Brandenburg and Wolfgang Brunner
	and Andreas Hofmeier and Marco Matzeder and Thomas Unfried},
  title = {Tree Drawings on the Hexagonal Grid},
  pages = {372--383},
  abstract = {We consider straight-line drawings of trees on a hexagonal grid. The
	hexagonal grid is an extension of the common grid with inner nodes
	of degree six. We restrict the number of directions used for the
	edges from each node to its children from one to five, and to five
	patterns: straight, Y, psi, X, and full. The psi-drawings generalize
	hv- or strictly upward drawings to ternary trees. We show that complete
	ternary trees have a psi-drawing on a square of size and general
	ternary trees can be drawn within area. Both bounds are optimal.
	Sub-quadratic bounds are also obtained for X-pattern drawings of
	complete tetra trees, and for full-pattern drawings of complete penta
	trees, which are 4-ary and 5-ary trees. These results parallel and
	complement the ones of Frati for straight-line orthogonal drawings
	of ternary trees. Moreover, we provide an algorithm for compacted
	straight-line drawings of penta trees on the hexagonal grid, such
	that the direction of the edges from a node to its children is given
	by our patterns and these edges have the same length. However, drawing
	trees on a hexagonal grid within a prescribed area or with unit length
	edges is NP-hard.},
  crossref = {GD2008},
  doi = {10.1007/978-3-642-00219-9_36}
}

@INPROCEEDINGS{Bachmaier2005,
  author = {Christian Bachmaier and Ulrik Brandes and Barbara Schlieper},
  title = {Drawing Phylogenetic Trees},
  pages = {1110--1121},
  abstract = {We present linear-time algorithms for drawing phylogenetic trees in
	radial and circular representations. In radial drawings given edge
	lengths (representing evolutionary distances) are preserved, but
	labels (names of taxons represented in the leaves) need to be adjusted,
	whereas in circular drawings labels are perfectly spread out, but
	edge lengths adjusted. Our algorithms produce drawings that are unique
	solutions to reasonable criteria and assign to each subtree a wedge
	of its own. The linear running time is particularly interesting in
	the circular case, because our approach is a special case of Tutte's
	barycentric layout algorithm involving the solution of a system of
	linear equations.},
  crossref = {ISAAC2005},
  doi = {10.1007/11602613_110}
}

@INPROCEEDINGS{Balzer2004,
  author = {Michael Balzer and Oliver Deussen},
  title = {Hierarchy based {3D} Visualization of Large Software Structures},
  pages = {81--82},
  abstract = {Modern object-oriented programs are hierarchical systems with many
	thousands of interrelated subsystems. Visualization helps developers
	to better comprehend these large and complex systems. This work presents
	a three-dimensional visualization technique that represents the static
	structure of object-oriented software using distributions of three-dimensional
	objects on a two-dimensional plane. The visual complexity is reduced
	by adjusting the transparency of object surfaces to the distance
	of the viewpoint. An approach called Hierarchical Net is proposed
	for a clear representation of the relationships between the subsystems.},
  crossref = {VISposter2004},
  doi = {10.1109/VISUAL.2004.39}
}

@INPROCEEDINGS{Balzer2005,
  author = {Michael Balzer and Oliver Deussen},
  title = {Voronoi Treemaps},
  pages = {49--56},
  abstract = {Treemaps are a well known method for the visualization of attributed
	hierarchical data. Previously proposed treemap layout algorithms
	are limited to rectangular shapes, which cause problems with the
	aspect ratio of the rectangles as well as with identifying the visualized
	hierarchical structure. The approach of Voronoi treemaps presented
	in this paper eliminates these problems through enabling subdivisions
	of and in polygons. Additionally, this allows for creating treemap
	visualizations within areas of arbitrary shape, such as triangles
	and circles, thereby enabling a more flexible adaptation of treemaps
	for a wider range of applications.},
  crossref = {INFOVIS2005},
  doi = {10.1109/INFVIS.2005.1532128}
}

@INPROCEEDINGS{Band2006,
  author = {Zvi Band and Ryen W. White},
  title = {{PygmyBrowse}: A small screen tree browser},
  pages = {514--519},
  abstract = {We present PygmyBrowse, a browser that allows users to navigate a
	tree data structure in a limited amount of display space. A pilot
	evaluation of PygmyBrowse was conducted, and results suggest that
	it reduces task completion times and increases user satisfaction
	over two alternative node-link tree browsers.},
  crossref = {CHIabs2006},
  doi = {10.1145/1125451.1125562}
}

@INPROCEEDINGS{Beaudoin1996,
  author = {Luc Beaudoin and Marc-Antoine Parent and Louis C. Vroomen},
  title = {Cheops: A Compact Explorer For Complex Hierarchies},
  pages = {87--92},
  abstract = {As the amount of electronic information explodes, hierarchies to handle
	this information become huge and complex. Visualizing and interacting
	with these hierarchies become daunting tasks. The problem is exacerbated
	if the visualization is to be done on massmarket personal computers,
	with limited processing power and visual resolution. Many of the
	current visualization techniques work effectively for hierarchies
	of 1000 nodes. But as the number of nodes increases toward 5000 nodes,
	these techniques tend to break down. Hierarchies above 5000 nodes
	usually require special modifications such as clustering, which can
	affect visual stability. This paper introduces Cheops, a novel approach
	to the representation, browsing and exploration of huge, complex
	information hierarchies such as the Dewey Decimal system, which can
	contain between 1 million and 1 billion nodes. The Cheops approach
	maintains context within a huge hierarchy, while simultaneously providing
	easy access to details. This paper will also present some preliminary
	results from usability tests performed on an 8 wide by 9 deep classification
	hierarchy, which if fully populated would contain over 19 million
	nodes.},
  crossref = {VIS1996},
  doi = {10.1109/VISUAL.1996.567745}
}

@INPROCEEDINGS{Bederson2001,
  author = {Benjamin B. Bederson},
  title = {{PhotoMesa}: A Zoomable Image Browser Using Quantum Treemaps and
	Bubblemaps},
  pages = {71--80},
  abstract = {PhotoMesa is a zoomable image browser that uses a novel treemap algorithm
	to present large numbers of images grouped by directory, or other
	available metadata. It uses a new interaction technique for zoomable
	user interfaces designed for novices and family use that makes it
	straightforward to navigate through the space of images, and impossible
	to get lost. PhotoMesa groups images using one of two new algorithms
	that lay out groups of objects in a 2D space-filling manner. Quantum
	treemaps are designed for laying out images or other objects of indivisible
	(quantum) size. They are a variation on existing treemap algorithms
	in that they guarantee that every generated rectangle will have a
	width and height that are an integral multiple of an input object
	size. Bubblemaps also fill space with groups of quantum-sized objects,
	but generate non-rectangular blobs, and utilize space more efficiently.},
  crossref = {UIST2001},
  doi = {10.1145/502348.502359}
}

@INPROCEEDINGS{Beermann2005,
  author = {Dale Beermann and Tamara Munzner and Greg Humphreys},
  title = {Scalable, Robust Visualization of Very Large Trees},
  pages = {37--44},
  abstract = {The TreeJuxtaposer system allowed visual comparison of large trees
	with guaranteed visibility of landmarks and Focus+Context navigation.
	While that system allowed exploration and comparison of larger datasets
	than previous work, it was limited to a single tree of 775,000 nodes
	by a large memory footprint. In this paper, we describe the theoretical
	limitations to TreeJuxtaposer's architecture that severely restrict
	its scalability. We provide two scalable, robust solutions to these
	limitations: TJC and TJC-Q. TJC is a system that supports browsing
	trees up to 15 million nodes by exploiting leading-edge graphics
	hardware while TJC-Q allows browsing trees up to 5 million nodes
	on commodity platforms. Both of these systems use a fast new algorithm
	for drawing and culling and benefit from a complete redesign of all
	data structures for more efficient memory usage and reduced preprocessing
	time.},
  crossref = {EUROVIS2005},
  url = {http://diglib.eg.org/EG/DL/WS/VisSym/EuroVis05/037-044.pdf}
}

@INPROCEEDINGS{Benson2010,
  author = {Jordan Riley Benson and Lee Sullvan and Rajiv Ramarajan and Frank
	Wimmer and Paul Hankey},
  title = {Using Orthographic Projection and Animation to Convey Treemap Structure},
  abstract = {We present an alternative treemap visualization method that maintains
	the space-filling and area comparison benefits of the standard treemap
	while improving the range of possible comparisons and the clarity
	of the hierarchy. Our visualization uses an orthographic stack representation
	and relies on interaction and animation to reveal the structure of
	the treemap to the user, but is still effective in a static environment
	once the user reaches a view that interests them.},
  crossref = {INFOVISposter2010},
  url = {http://blogs.sas.com/peerrevue/uploads/OrthographicTreeMap-summary.pdf}
}

@INPROCEEDINGS{Berg2011,
  author = {Mark de Berg and Bettina Speckmann and Vincent van der Weele},
  title = {{Convex Treemaps} with Bounded Aspect Ratio},
  pages = {71--74},
  abstract = {Treemaps are a popular technique to visualize hierarchical data. The
	input is a weighted tree T where the weight of each node is the sum
	of the weights of its children. A treemap for T is a hierarchical
	partition of a rectangle into simply connected regions, usually rectangles.
	Each region represents a node of T and the area of each region is
	proportional to the weight of the corresponding node. An important
	quality criterium for treemaps is the aspect ratio of its regions.
	Unfortunately, one cannot bound the aspect ratio if the regions are
	restricted to be rectangles. Hence Onak and Sidiropoulos introduced
	polygonal partitions, which use convex polygons. We are the first
	to obtain convex partitions with optimal aspect ratio O(depth(T)).
	We also consider the important special case that depth(T)=1, that
	is, single-level treemaps. We show how to construct convex single-level
	treemaps that use only four simple shapes for the regions and have
	aspect ratio at most 34/7.},
  crossref = {EuroCG2011},
  url = {http://eurocg11.inf.ethz.ch/abstracts/62.pdf}
}

@INPROCEEDINGS{Bernstein2000,
  author = {Rocky Bernstein},
  title = {{xps} -- Dynamic Process Tree Watching Under {X}},
  pages = {95--100},
  abstract = {The xps program dynamically displays the Unix processes as a tree
	or forest in an X Window, the roots on the left and the leaf processes
	(those with no children) on the right. The status of each process
	running, sleeping, stopped, etc., can be indicated by different colors.
	Different users can appear as different colors too. Process selection
	can be made per user, all users, or through a regular-expression
	pattern. In contrast to the terminal-based pstree or tree-widget
	based programs, the tree display uses diagonal lines, and effort
	is made to effectively use the full 2-dimensional area of the screen
	by balancing levels and centering the children of a node between
	their parent. A goal of the program is to give an idea of what's
	going on graphically as things may be constantly changing. Therefore
	the display algorithm tries to keep processes close to their parents
	to reduce the amount of scrolling to see localized process creation
	and destruction. Some effort is also given to make sure that the
	tree layout doesn't get wildly reorganized when there are small or
	localized changes. This makes it easier for the eye to pick up and
	recognize the changes over a potentially large display area. We describe
	here criteria for tree animations such as this one and how the xps
	layout algorithm works. There are some other miscellaneous features
	of xps. One can select viewing the processes by a single user, a
	regular expression for users, by all users, and perhaps show kernel
	processes. One can click on a process to get more information (via
	ps or a user-specified program) about that process, send a signal,
	or set the process priority, assuming you have the permission to
	do so. Since programs of this ilk can consume a bit of CPU on their
	own, some effort has been made to turn off the update process when
	the program is iconified or not visible for some other reason such
	as being obscured by another window. Some attention has been paid
	to make algorithm display fairly fast in most situations, although
	it has to be admitted that this comes sometimes at the expense of
	a nicer layout.},
  crossref = {LISA2000},
  url = {http://www.usenix.org/events/lisa00/bernstein.html}
}

@INPROCEEDINGS{Bladh2004,
  author = {Thomas Bladh and David A. Carr and Jeremiah Scholl},
  title = {Extending Tree-Maps to Three Dimensions: A Comparative Study},
  pages = {50--59},
  abstract = {This paper presents StepTree, an information visualization tool designed
	for depicting hierarchies, such as directory structures. StepTree
	is similar to the hierarchy-visualization tool, Treemap, in that
	it uses a rectangular, space-filling methodology, but differs from
	Treemap in that it employs three-dimensional space, which is used
	to more clearly convey the structural relationships of the hierarchy.
	The paper includes an empirical study comparing typical search and
	analysis tasks using StepTree and Treemap. The study shows that users
	perform significantly better on tasks related to interpreting structural
	relationships when using StepTree. In addition, users achieved the
	same performance with StepTree and Treemap when doing a range of
	other common interpretative and navigational tasks.},
  crossref = {APCHI2004},
  doi = {10.1007/978-3-540-27795-8_6}
}

@INPROCEEDINGS{Blanch2006,
  author = {Renaud Blanch and \'Eric Lecolinet},
  title = {Navigation Techniques for {Zoomable Treemaps}},
  pages = {49--50},
  abstract = {This paper presents a new technique called zoomable treemaps that
	makes it possible to navigate in very large trees. It integrates
	several efficient interaction techniques that enable multi-scale
	and structure-aware navigation.},
  crossref = {UISTdemos2006},
  url = {http://www.acm.org/uist/archive/adjunct/2006/pdf/demos/p49-blanch.pdf}
}

@INPROCEEDINGS{Blanch2007a,
  author = {Renaud Blanch and \'Eric Lecolinet},
  title = {Treemaps zoomables: techniques d'interaction multi-\'echelles pour
	les treemaps},
  pages = {131--138},
  abstract = {Some efficient visualizations (such as treemaps) have been proposed
	for trees, but the interaction they provide to explore and acces
	data is often poor, especially for very large trees. We have designed
	a consistent set of navigation techniques that makes it possible
	to use treemaps as zoomable interfaces. We introduce structure-aware
	navigation, the property of using the structure of the displayed
	information to guide navigation, property that our interaction techniques
	share.},
  crossref = {IHM2007},
  doi = {10.1145/1541436.1541462}
}

@INPROCEEDINGS{Boardman2000,
  author = {Richard Boardman},
  title = {{Bubble Trees} -- The visualization of hierarchical information structures},
  pages = {315--316},
  abstract = {A tree visualization mechanism is proposed, based on the natural property
	of trees to recursively sub-categorize themselves into sub-trees.
	Each sub-tree is graphically represented as a bubble, which aggregates
	detail by enclosing lower-level information. Navigation and information
	retrieval are facilitated through an elegant set of browsing interactions.
	The interface is useful for tasks where users are required to develop
	a mental model of a classification system. The interactive nature
	of bubble trees allows users to explore and work out relationships
	for themselves.},
  crossref = {CHIabs2000},
  doi = {10.1145/633292.633484}
}

@INPROCEEDINGS{Bohanec2007,
  author = {Marko Bohanec},
  title = {{DEXiTree}: A program for pretty drawing of trees},
  pages = {7--10},
  abstract = {This paper presents DEXiTree, a computer program for drawing trees.
	In principle, DEXiTree is aimed at making nice drawings of attribute
	trees made by DEXi, a computer program for qualitative multi-attribute
	decision modelling. Apart from that, DEXiTree is quite a general
	and powerful tree-drawing program that implements four different
	tree-drawing algorithms (called Distribute, Align, Walker, and QP),
	draws trees in four different directions (top-down, left-right, bottom-up
	and right-left) and provides an extensive set of parameters for controlling
	the appearance of trees and their components. DEXiTree’s functionality
	includes loading a decision model from a DEXi file, interactively
	designing the tree layout, saving and loading the layout using an
	XML format, and rendering the drawing in two graphic formats: vector
	and raster.},
  crossref = {IS2007},
  url = {http://kt.ijs.si/MarkoBohanec/pub/IS2007_DEXiTree.pdf}
}

@INPROCEEDINGS{Boutin2005,
  author = {Fran\c{c}ois Boutin and J\'er\^ome Thi\`evre and Mountaz Hasco\"et},
  title = {Multilevel Compound Tree -- Construction Visualization and Interaction},
  pages = {847--860},
  abstract = {Several hierarchical clustering techniques have been proposed to visualize
	large graphs, but fewer solutions suggest a focus based approach.
	We propose a multilevel clustering technique that produces in linear
	time a contextual clustered view depending on a user-focus. We get
	a tree of clusters where each cluster - called meta-silhouette -
	is itself hierarchically clustered into an inclusion tree of silhouettes.
	Resulting Multilevel Silhouette Tree (MuSi-Tree) has a specific structure
	called multilevel compound tree. This work builds upon previous work
	on a compound tree structure called MO-Tree. The work presented in
	this paper is a major improvement over previous work by (1) defining
	multilevel compound tree as a more generic structure, (2) proposing
	original space-filling visualization techniques to display it, (3)
	defining relevant interaction model based on both focus changes and
	graph filtering techniques and (4) reporting from case studies in
	various fields: co-citation graphs, related-document graphs and social
	graphs.},
  crossref = {INTERACT2005},
  doi = {10.1007/11555261_67}
}

@INPROCEEDINGS{Bruls2000,
  author = {Mark Bruls and Kees Huizing and Jarke van Wijk},
  title = {{Squarified Treemaps}},
  pages = {33--42},
  abstract = {An extension to the treemap method for the visualization of hierarchical
	information, such as directory structures and organization structures,
	is presented. The standard treemap method often gives thin, elongated
	rectangles. As a result, rectangles are difficult to compare and
	to select. A new method is presented to generate lay-outs in which
	the rectangles approximate squares. To strenghten the visualization
	of the structure, shaded frames are used around groups of related
	nodes.},
  crossref = {VISSYM2000},
  url = {http://diglib.eg.org/EG/DL/WS/VisSym/VisSym00/033-042.pdf}
}

@INPROCEEDINGS{Brunner2010,
  author = {Wolfgang Brunner and Marco Matzeder},
  title = {Drawing ordered $(k-1)$-ary trees on $k$-grids},
  pages = {105--116},
  abstract = {We explore the complexity of drawing ordered $(k-1)$-ary trees on
	grids with k directions for $k\in\{4,6,8\}$ and within a given area.
	This includes, e.g., ternary trees drawn on the orthogonal grid.
	For aesthetically pleasing tree drawings on these grids, we additionally
	present various restrictions similar to the common hierarchical case.
	First, we generalize the NP-hardness of minimal width in hierarchical
	drawings of ordered trees to $(k-1)$-ary trees on k-grids and then
	we generalize the Reingold and Tilford algorithm to k-grids.},
  crossref = {GD2010},
  doi = {10.1007/978-3-642-18469-7_10}
}

@INPROCEEDINGS{Buchheim2002,
  author = {Christoph Buchheim and Michael J\"unger and Sebastian Leipert},
  title = {Improving {W}alker's Algorithm to Run in Linear Time},
  pages = {347--364},
  abstract = {The algorithm of Walker is widely used for drawing trees of unbounded
	degree, and it is widely assumed to run in linear time, as the author
	claims in his article. But the presented algorithm clearly needs
	quadraticrun time. We explain the reasons for that and present a
	revised algorithm that creates the same layouts in linear time.},
  crossref = {GD2002},
  doi = {10.1007/3-540-36151-0_32}
}

@INPROCEEDINGS{Buchin2011,
  author = {Kevin Buchin and David Eppstein and Maarten L\"offler and Martin
	N\"ollenburg and Rodrigo I. Silveira},
  title = {Adjacency-Preserving Spatial {Treemaps}},
  year = {2011},
  pages = {159--170},
  abstract = {Rectangular layouts, subdivisions of an outer rectangle into smaller
	rectangles, have many applications in visualizing spatial information,
	for instance in rectangular cartograms in which the rectangles represent
	geographic or political regions. A spatial treemap is a rectangular
	layout with a hierarchical structure: the outer rectangle is subdivided
	into rectangles that are in turn subdivided into smaller rectangles.
	We describe algorithms for transforming a rectangular layout that
	does not have this hierarchical structure, together with a clustering
	of the rectangles of the layout, into a spatial treemap that respects
	the clustering and also respects to the extent possible the adjacencies
	of the input layout.},
  crossref = {WADS2011},
  doi = {10.1007/978-3-642-22300-6_14}
}

@INPROCEEDINGS{Buchin2011b,
  author = {Kevin Buchin and Bettina Speckmann and Kevin Verbeek},
  title = {Angle-Restricted {Steiner} Arborescences for {Flow Map} Layout},
  year = {2011},
  pages = {35--38},
  abstract = {Flow maps visualize the movement of objects between places. One or
	more sources are connected to several targets by arcs whose thickness
	corresponds to the amount of flow between a source and a target.
	Flow maps reduce visual clutter by merging (bundling) lines smoothly
	and by avoiding self-intersections. We present algorithms that compute
	crossing-free flows of high visual quality. To this end we introduce
	a new variant of the geometric Steiner arborescence problem. The
	goal is to connect the targets to a source with a tree of minimal
	length whose arcs obey a certain restriction on the angle they form
	with the source. Such an angle-restricted Steiner arborescence, or
	simply flow tree, naturally induces a clustering on the targets and
	smoothly bundles arcs. We study the properties of optimal flow trees
	and show that they consist of logarithmic spirals and straight lines.
	Computing optimal flow trees is NP-hard. Hence we consider a variant
	of flow trees which uses only logarithmic spirals, so called spiral
	trees. Spiral trees approximate flow trees within a factor depending
	on the angle restriction. Computing optimal spiral trees remains
	NP-hard. We present an efficient 2-approximation for spiral trees,
	which can be extended to avoid certain types of obstacles.},
  crossref = {EuroCG2011},
  url = {http://eurocg11.inf.ethz.ch/abstracts/25.pdf}
}

@INPROCEEDINGS{Budiu2007,
  author = {Raluca Budiu and Peter Pirolli},
  title = {Modeling Navigation in {Degree-of-Interest Trees}},
  pages = {845--850},
  abstract = {We present an ACT-R (Anderson and Lebiere, 1998) computational model
	of how people navigate in a degree-of-interest (DOI) tree. The model
	incorporates a visual salience function that determines which part
	of the display to attend to next. The salience function uses visual
	features of the display (e.g., distances) and semantic features of
	labels (e.g., information scent). The model was compared against
	data from participants and provided medium to strong fits to latencies
	and the number of nodes visited by the participants. The model shows
	that it is useful to distinguish between category-based versus similarity-based
	information scent. It also suggests that visual distance and scent
	may interact with one another, with scent playing a greater role
	at distances close to the current node in the visual focus.},
  crossref = {CogSci2007},
  url = {http://csjarchive.cogsci.rpi.edu/Proceedings/2007/docs/p845.pdf}
}

@INPROCEEDINGS{Budiu2006,
  author = {Raluca Budiu and Peter Pirolli and Michael Fleetwood},
  title = {Navigation in degree of interest trees},
  pages = {457--462},
  abstract = {We present an experiment that compares how people perform search tasks
	in a degree-of-interest browser and in a Windows-Explorer-like browser.
	Our results show that, whereas users do attend to more information
	in the DOI browser, they do not complete the task faster than in
	an Explorer-like browser. However, in both types of browser, users
	are faster to complete high information scent search tasks than low
	information scent tasks. We present an ACT-R computational model
	of the search task in the DOI browser. The model describes how a
	visual search strategy may combine with semantic aspects of processing,
	as captured by information scent. We also describe a way of automatically
	estimating information scent in an ontological hierarchy by querying
	a large corpus (in our case, Google's corpus).},
  crossref = {AVI2006},
  doi = {10.1145/1133265.1133358}
}

@INPROCEEDINGS{Burch2008,
  author = {Michael Burch and Fabian Beck and Stephan Diehl},
  title = {{Timeline Trees}: visualizing sequences of transactions in information
	hierarchies},
  pages = {75--82},
  abstract = {In many applications transactions between the elements of an information
	hierarchy occur over time. For example, the product offers of a department
	store can be organized into product groups and subgroups to form
	an information hierarchy. A market basket consisting of the products
	bought by a customer forms a transaction. Market baskets of one or
	more customers can be ordered by time into a sequence of transactions.
	Each item in a transaction is associated with a measure, for example,
	the amount paid for a product. In this paper we present a novel method
	for visualizing sequences of these kinds of transactions in information
	hierarchies. It uses a tree layout to draw the hierarchy and a timeline
	to represent progression of transactions in the hierarchy. We have
	developed several interaction techniques that allow the users to
	explore the data. Smooth animations help them to track the transitions
	between views. The usefulness of the approach is illustrated by examples
	from several very different application domains.},
  crossref = {AVI2008},
  doi = {10.1145/1385569.1385584}
}

@INPROCEEDINGS{Burch2010,
  author = {Michael Burch and Michael Raschke and Daniel Weiskopf},
  title = {Indented Pixel Tree Plots},
  pages = {338--349},
  abstract = {We introduce Indented Pixel Tree Plots (IPTPs): a novel pixel-based
	visualization technique for depicting large hierarchies. It is inspired
	by the visual metaphor of indented outlines, omnipresent in graphical
	file browsers and pretty printing of source code. Inner vertices
	are represented as vertically arranged lines and leaf groups as horizontally
	arranged lines. A recursive layout algorithm places parent nodes
	to the left side of their underlying tree structure and leaves of
	each subtree grouped to the rightmost position. Edges are represented
	only implicitly by the vertically and horizontally aligned structure
	of the plot, leading to a sparse and redundant-free visual representation.
	We conducted a user study with 30 subjects in that we compared IPTPs
	and node-link diagrams as a within-subjects variable. The study indicates
	that working with IPTPs can be learned in less than 10 minutes. Moreover,
	IPTPs are as effective as node-link diagrams for accuracy and completion
	time for three typical tasks; participants generally preferred IPTPs.
	We demonstrate the usefulness of IPTPs by understanding hierarchical
	features of huge trees such as the NCBI taxonomy with more than 300,000
	nodes.},
  crossref = {ISVC2010},
  doi = {10.1007/978-3-642-17289-2_33}
}

@INPROCEEDINGS{Burch2011a,
  author = {Michael Burch and Hansj\"org Schmauder and Daniel Weiskopf},
  title = {Indented Pixel Tree Browser for Exploring Huge Hierarchies},
  pages = {301--312},
  abstract = {In this paper we introduce the Indented Pixel Tree Browser -- an interactive
	tool for exploring, annotating, and comparing huge hierarchical structures
	on different levels of granularity. We exploit the indented visual
	metaphor to map tree structures to one-dimensional zigzag curves
	to primarily achieve an overview representation for the entire hierarchy.
	We focus on space-efficiency and simultaneous uncovering of tree-specific
	phenomena. Each displayed plot can be filtered for substructures
	that are mapped to a larger space and hence, unhide more fine-granular
	substructures that are hidden in the compressed overview. By representing
	tree structures side-by-side, the viewer can easily compare them
	visually and detect similar patterns and also anomalies. In our approach,
	we follow the information seeking mantra: overview first, zoom and
	filter, then details-on-demand. More interactive features such as
	expanding and collapsing of nodes, applying different color codings,
	or distorting the tree horizontally as well as vertically support
	a viewer when exploring huge hierarchical data sets. The usefulness
	of our interactive browsing tool is demonstrated in a case study
	for the NCBI taxonomy that contains 324,276 species and organisms
	that are hierarchically organized.},
  crossref = {ISVC2011},
  doi = {10.1007/978-3-642-24028-7_28}
}

@INPROCEEDINGS{Card2002,
  author = {Stuart K. Card and David Nation},
  title = {Degree-of-interest trees: a component of an attention-reactive user
	interface},
  pages = {231--245},
  abstract = {This paper proposes Degree-of-Interest trees. These trees use degree-of-interest
	calculations and focus+context visualization methods, together with
	bounding constraints, to fit within pre-established bounds. The method
	is an instance of an emerging "attention-reactive" user interface
	whose components are designed to snap together in bounded spaces.},
  crossref = {AVI2002},
  doi = {10.1145/1556262.1556300}
}

@INPROCEEDINGS{Card2006,
  author = {Stuart K. Card and Bongwon Suh and Bryan A. Pendleton and Jeffrey
	Heer and John W. Bodnar},
  title = {{TimeTree}: Exploring Time Changing Hierarchies},
  pages = {3--10},
  abstract = {Intelligence analysis often involves the task of gathering information
	about an organization. Knowledge about individuals in an organization
	and their relationships, often represented as a hierarchical organization
	chart, is crucial for understanding the organization. However, it
	is difficult for intelligence analysts to follow all individuals
	in an organization. Existing hierarchy visualizations have largely
	focused on the visualization of fixed structures and can not effectively
	depict the evolution of a hierarchy over time. We introduce TimeTree,
	a novel visualization tool designed to enable exploration of a changing
	hierarchy. TimeTree enables analysts to navigate the history of an
	organization, identify events associated with a specific entity (visualized
	on a TimeSlider), and explore an aggregate view of an individual's
	career path (a CareerTree). We demonstrate the utility of TimeTree
	by investigating a set of scenarios developed by an expert intelligence
	analyst. The scenarios are evaluated using a real dataset composed
	of eighteen thousand career events from more than eight thousand
	individuals. Insights gained from this analysis are presented.},
  crossref = {VAST2006},
  doi = {10.1109/VAST.2006.261450}
}

@INPROCEEDINGS{Carlson2006,
  author = {Josiah Carlson and David Eppstein},
  title = {Trees with convex faces and optimal angles},
  pages = {77--88},
  abstract = {We consider drawings of trees in which all edges incident to leaves
	can be extended to infinite rays without crossing, partitioning the
	plane into infinite convex polygons. Among all such drawings we seek
	the one maximizing the angular resolution of the drawing. We find
	linear time algorithms for solving this problem, both for plane trees
	and for trees without a fixed embedding. In any such drawing, the
	edge lengths may be set independently of the angles, without crossing;
	we describe multiple strategies for setting these lengths.},
  crossref = {GD2006},
  doi = {10.1007/978-3-540-70904-6_9}
}

@INPROCEEDINGS{Carpendale2004,
  author = {Sheelagh Carpendale and Anand Agarawala},
  title = {{PhylloTrees}: Harnessing Nature's Phyllotactic Patterns for Tree
	Layout},
  pages = {7--8},
  abstract = {We explore the use of nature’s phyllotactic patterns to inform the
	layout of hierarchical data. These naturally occurring patterns provide
	a non-overlapping, optimal packing when the total number of nodes
	is not known a priori. We present a family of expandable tree layouts
	based on these patterns.},
  crossref = {INFOVISposter2004},
  doi = {10.1109/INFVIS.2004.53}
}

@INPROCEEDINGS{Carriere1995,
  author = {Jeromy Carriere and Rick Kazman},
  title = {Research report. Interacting with huge hierarchies: Beyond {Cone
	Trees}},
  pages = {74--81},
  abstract = {The paper describes an implementation of a tool for visualizing and
	interacting with huge information hierarchies, and some preliminary
	empirical evaluation of the tool's efficacy. Existing systems for
	visualizing huge hierarchies using cone trees "break down" once the
	hierarchy to be displayed exceeds roughly 1000 nodes, due to increasing
	visual clutter. The paper describes a system called fsviz which visualizes
	arbitrarily large hierarchies while retaining user control. This
	is accomplished by augmenting cone trees with several graphical and
	interaction techniques: usage-based filtering, animated zooming,
	hand-coupled rotation, fish-eye zooming, coalescing of distant nodes,
	texturing, effective use of colour for depth cueing, and the applications
	of dynamic queries. The fsviz system also improves upon earlier cone
	tree visualization systems through a more elaborate node layout algorithm.
	This algorithm enhances the usefulness of cone tree visualization
	for large hierarchies by all but eliminating clutter.},
  crossref = {INFOVIS1995},
  doi = {10.1109/INFVIS.1995.528689}
}

@INPROCEEDINGS{Chaudhuri2009,
  author = {Abon Chaudhuri and Han-Wei Shen},
  title = {A Self-adaptive Treemap-based Technique for Visualizing Hierarchical
	Data in {3D}},
  pages = {105--112},
  abstract = {In this paper, we present a novel adaptive visualization technique
	where the constituting polygons dynamically change their geometry
	and other visual attributes depending on user interaction. These
	changes take place with the objective of conveying required level
	of detail to the user through each view. Our proposed technique is
	successfully applied to build a treemap-based but 3D visualization
	of hierarchical data, a widely used information structure. This new
	visualization exploits its adaptive nature to address issues like
	cluttered display, imperceptible hierarchy, lack of smooth zoom-in
	and out technique which are common in tree visualization. We also
	present an algorithm which utilizes the flexibility of our proposed
	technique to deal with occlusion, a problem inherent in any 3D information
	visualization. On one hand, our work establishes adaptive visualization
	as a means of displaying tree-structured data in 3D. On the other,
	it promotes the technique as a potential candidate for being employed
	to visualize other information structures also.},
  crossref = {PACIFICVIS2009},
  doi = {10.1109/PACIFICVIS.2009.4906844}
}

@INPROCEEDINGS{Chevalier2007,
  author = {Fanny Chevalier and David Auber and Alexandru Telea},
  title = {Structural Analysis and Visualization of {C}++ Code Evolution using
	Syntax Trees},
  pages = {90--97},
  abstract = {We present a method to detect and visualize evolution patterns in
	C++ source code. Our method consists of three steps. First, we extract
	an annotated syntax tree (AST) from each version of a given C++ source
	code. Next, we hash the extracted syntax nodes based on a metric
	combining structure and type information, and construct matches (correspondences)
	between similar-hash subtrees. Our technique detects code fragments
	which have not changed, or changed little, during the software evolution.
	By parameterizing the similarity metric, we can flexibly decide what
	is considered to be identical or not during the software evolution.
	Finally, we visualize the evolution of the code structure by emphasizing
	both changing and constant code patterns. We demonstrate our technique
	on a versioned code base containing a variety of changes ranging
	from simple to complex.},
  crossref = {IWPSE2007},
  doi = {10.1145/1294948.1294971}
}

@INPROCEEDINGS{EdChi1998,
  author = {Ed H. Chi and James Pitkow and Jock Mackinlay and Peter Pirolli and
	Rich Gossweiler and Stuart K. Card},
  title = {Visualizing the evolution of Web ecologies},
  pages = {400--407},
  abstract = {Several visualizations have emerged which attempt to visualize all
	or part of the World Wide Web. Those visualizations, however, fail
	to present the dynamically changing ecology of users and documents
	on the Web. We present new techniques for Web Ecology and Evolution
	Visualization (WEEV). Disk Trees represent a discrete time slice
	of the Web ecology. A collection of Disk Trees forms a Time Tube,
	representing the evolution of the Web over longer periods of time.
	These visualizations are intended to aid authors and webmasters with
	the production and organization of content, assist Web surfers making
	sense of information, and help researchers understand the Web.},
  crossref = {CHI1998},
  doi = {10.1145/274644.274699}
}

@INPROCEEDINGS{Choi2011,
  author = {Junghong Choi and Oh-hyun Kwon and Kyungwon Lee},
  title = {Strata Treemaps},
  pages = {87},
  abstract = {Treemap is a method of visualization to recognize a hierarchical structure
	of data using the size and arrangement of nested rectangles. A limitation
	of a treemap is the difficulty to discern the structure of a hierarchy.
	Several approaches have been proposed to improve the visibility of
	the hierarchical structure. These approaches involve the use of a
	border or padding to emphasize the hierarchical structure. However,
	this leads to a disparity between the node weight and the relative
	node size.},
  crossref = {SIGGRAPHposter2011},
  doi = {10.1145/2037715.2037813}
}

@INPROCEEDINGS{Chuah1998,
  author = {Mei C. Chuah},
  title = {Dynamic Aggregation with Circular Visual Designs},
  pages = {35--43},
  abstract = {One very effective method for managing large data sets is aggregation
	or binning. We consider two aggregation methods that are tightly
	coupled with interactive manipulation and the visual representation
	of the data. Through this integration we hope to provide effective
	support for the aggregation process, specifically by enabling: 1)
	automatic aggregation, 2) continuous change and control of the aggregation
	level, 3) spatially based aggregates, 4) context maintenance across
	different aggregate levels, and 5) feedback on the level of aggregation.},
  crossref = {INFOVIS1998},
  doi = {10.1109/INFVIS.1998.729557}
}

@INPROCEEDINGS{Chuanxi2011,
  author = {Chen Chuanxi and Qi Mian},
  title = {Visualization of Syntax Tree Based on {VML}},
  pages = {538--541},
  abstract = {In the Chinese teaching and research, it often needs to draw syntax
	tree for the analyzing of relationship among compositions of sentence.
	Drawn syntax tree manually has many defects, such as having huge
	workload, needing immense storage capacity and so on. So it is of
	importance to do research of automatically generating syntax tree
	and its visualization. In this paper, it proposes a method to generate
	syntax tree automatically and display the syntax tree in web page
	by using VML technology. By comparing the syntax trees generated
	in this paper with the syntax trees got from Treebank of PKU, the
	result shows that the method of coordinate computing proposed in
	this paper is more precision, which also demonstrates the efficiency
	of the visualization method.},
  crossref = {ISIE2011},
  doi = {10.1109/ISIE.2011.68}
}

@INPROCEEDINGS{Churcher1999,
  author = {Neville Churcher and Lachlan Keown and Warwick Irwin},
  title = {Virtual Worlds for Software Visualisation},
  pages = {9--16},
  abstract = {Understanding, quickly, completely and correctly, is crucial to every
	phase of the software development process. As system size and complexity
	continues to grow, effective visualisation of system components,
	together with their properties and relationships, becomes increasingly
	important in achieving understanding. Virtual worlds allow more information
	to be presented in visualisations while minimising the impact of
	cognitive information overload. In this paper, we describe our application
	of virtual worlds to visualisation of software engineering artifacts
	and present some examples from our work on object oriented software
	systems.},
  crossref = {SOFTVIS1999},
  url = {http://www.cosc.canterbury.ac.nz/research/RG/svg/softvis99/softvis99-churcher-keown-irwin.pdf}
}

@INPROCEEDINGS{Cleary2004,
  author = {Brendan Cleary and Chris Exton},
  title = {{CHIVE} -- A program source visualisation framework},
  pages = {268--269},
  abstract = {The CHIVE visualisation framework is an attempt to provide program
	comprehension and visualisation tool developers with a flexible means
	for creating 3-dimensional visualisations of hierarchies such as
	those that occur in program source. The CHIVE framework supports
	user definable datasets, multiple graph layouts and an environment
	in which users can interact with visualisations created from applying
	a graph layout to a dataset.},
  crossref = {WPC2004},
  doi = {10.1109/WPC.2004.1311074}
}

@INPROCEEDINGS{Cockburn2000,
  author = {Andy Cockburn and Bruce McKenzie},
  title = {An Evaluation of {Cone Trees}},
  pages = {425--436},
  abstract = {Cone Trees are an appealing interactive 3D visualization technique
	for hierarchical data structures. They were originally intended to
	maximise effective use of available screen space and to better exploit
	the abilities of the human perceptual system. Prior work has focused
	on the fidelity of the visualization rather than providing empirical
	user studies. This paper describes the design, implementation and
	evaluation of a low-fidelity animated and rapidly interactive 3D
	cone tree system. Results of the evaluation show that our subjects
	were slower at locating data using cone trees than when using a 'normal'
	tree browser, and that their performance deteriorated rapidly as
	the branching factor of the data-structure increased. Qualitative
	results, however, indicate that the subjects were enthusiastic about
	the cone tree visualization and that they felt it provided a better
	'feel' for the structure of the information space.},
  crossref = {HCI2000},
  url = {http://hdl.handle.net/10092/522}
}

@INPROCEEDINGS{Crescenzi1997,
  author = {Pilu Crescenzi and Paolo Penna},
  title = {Minimum-area h-v drawings of complete binary trees},
  pages = {371--382},
  abstract = {We study the area requirement of h-v drawings of complete binary trees.
	An h-v drawing of a binary tree t is a drawing of t such that (a)
	nodes are points with integer coordinates, (b) each edge is either
	a rightward-horizontal or a downward-vertical straight-line segment
	from a node to one of its children, (c) edges do not intersect, and
	(d) if t 1 and t 2 are immediate subtrees of a node u, the enclosing
	rectangles of the drawings of t 1 and t 2 are disjoint. We prove
	that, for any complete binary tree t of height h SQRT((n+1)/2)+3.5
	if h is odd, (b) 2.5n–3.25SQRT(n+1)+3.5 otherwise. As far as we know,
	this is one of the few examples in which a closed formula for the
	minimum-area drawing of a graph has been explicitly found. Furthermore
	this minimum-area h-v drawing can be constructed in linear time.
	As a consequence of this result and the result of Trevisan (1996),
	we have that h-v drawings are provably less area-efficient than strictly
	upward drawings when we restrict ourselves to complete binary trees.
	We also give analogous results for the minimum-perimeter and the
	minimum-enclosing square area h-v drawings.},
  crossref = {GD1997},
  doi = {10.1007/3-540-63938-1_82}
}

@INPROCEEDINGS{Csallner2003,
  author = {Christoph Csallner and Marcus Handte and Othmar Lehmann and John
	Stasko},
  title = {{FundExplorer}: Supporting the diversification of mutual fund portfolios
	using {C}ontext {T}reemaps},
  pages = {203--208},
  abstract = {An equity mutual fund is a financial instrument that invests in a
	set of stocks. Any two different funds may partially invest in some
	of the same stocks, thus overlap is common. Portfolio diversification
	aims at spreading an investment over many different stocks in search
	of greater returns. Helping people with portfolio diversification
	is challenging because it requires informing them about both their
	current portfolio of stocks held through funds and the other stocks
	in the market not invested in yet. Current stock/fund visualization
	systems either waste screen real estate and visualization of all
	data points. We have developed a system called FundExplorer that
	implements a distorted treemap to visualize both the amount of money
	invested in a person's fund portfolio and the context of remaining
	market stocks. The FundExplorer system enables people to interactively
	explore diversification possibilities with their portfolios.},
  crossref = {INFOVIS2003},
  doi = {10.1109/INFVIS.2003.1249027}
}

@INPROCEEDINGS{Cuadros2007,
  author = {Ana M. Cuadros and Fernando V. Paulovich and Rosane Minghim and Guilherme
	P. Telles},
  title = {Point Placement by Phylogenetic Trees and its Application to Visual
	Analysis of Document Collections},
  pages = {99--106},
  abstract = {The task of building effective representations to visualize and explore
	collections with moderate to large number of documents is hard. It
	depends on the evaluation of some distance measure among texts and
	also on the representation of such relationships in bi- dimensional
	spaces. In this paper we introduce an alternative approach for building
	visual maps of documents based on their content similarity, through
	reconstruction of phylogenetic trees. The tree is capable of representing
	relationships that allows the user to quickly recover information
	detected by the similarity metric. For a variety of text collections
	of different natures we show that we can achieve improved exploration
	capability and more clear visualization of relationships amongst
	documents.},
  crossref = {VAST2007},
  doi = {10.1109/VAST.2007.4389002}
}

@INPROCEEDINGS{Dachselt2001,
  author = {Raimund Dachselt and J\"urgen Ebert},
  title = {Collapsible Cylindrical Trees: A Fast Hierarchical Navigation Technique},
  pages = {79-86},
  abstract = {This paper proposes a new visualization and interaction technique
	for medium-sized trees, called Collapsible Cylindrical Trees (CCT).
	Child nodes are mapped on rotating cylinders, which will be dynamically
	displayed or hidden to achieve a useful balance of detail and context.
	Besides a comprehensible three-dimensional visualization of trees,
	the main feature of CCT is a very fast and intuitive interaction
	with the displayed nodes. Only a single click is needed to reach
	every node and perform an action on it, such as displaying a web
	page. The CCT browsing technique was developed for interaction with
	web hierarchies but is not limited to this domain. We also present
	sample implementations of CCT using VRML, which show the usefulness
	of this intuitive tree navigation technique.},
  crossref = {INFOVIS2001},
  doi = {10.1109/INFVIS.2001.963284}
}

@INPROCEEDINGS{Demaine2011,
  author = {Erik D. Demaine and Andr\'e Schulz},
  title = {Embedding Stacked Polytopes on a Polynomial-Size Grid},
  pages = {1177--1187},
  abstract = {We show how to realize a stacked 3D polytope (formed by repeatedly
	stacking a tetrahedron onto a triangular face) by a strictly convex
	embedding with its n vertices on an integer grid of size $O(n^4)\timesO(n^4)\timesO(n^{18})$.
	We use a perturbation technique to construct an integral 2D embedding
	that lifts to a small 3D polytope, all in linear time. This result
	solves a question posed by G\"unter M. Ziegler, and is the first
	nontrivial subexponential upper bound on the long-standing open question
	of the grid size necessary to embed arbitrary convex polyhedra, that
	is, about efficient versions of Steinitz's 1916 theorem. An immediate
	consequence of our result is that $O(\log n)$-bit coordinates suffice
	for a greedy routing strategy in planar 3-trees.},
  crossref = {SODA2011},
  url = {http://www.siam.org/proceedings/soda/2011/SODA11_088_demainee.pdf}
}

@INPROCEEDINGS{Demetrescu1999,
  author = {Camil Demetrescu and Giuseppe Di Battista and Irene Finocchi and
	Giuseppe Liotta and Maurizio Patrignani and Maurizio Pizzonia},
  title = {Infinite trees and the future},
  pages = {379--391},
  abstract = {We study the problem of designing layout facilities for the navigation
	of an "infinite" graph, i.e. a graph that is so large that its visualization
	is unfeasible, even by gluing together all the screen snapshots that
	a user can take during the navigation. We propose a framework for
	designing layout facilities that support the navigation of an infinite
	tree. The framework allows to exploit the knowledge of future moves
	of the user in order to reduce the changes in her mental map during
	the navigation. Variants of the classical Reingold-Tilford algorithm
	are presented and their performance is studied both experimentally
	and analytically.},
  crossref = {GD1999},
  doi = {10.1007/3-540-46648-7_39}
}

@INPROCEEDINGS{Denier2009,
  author = {Simon Denier and Houari Sahraoui},
  title = {Understanding the use of inheritance with visual patterns},
  pages = {79-88},
  abstract = {The goal of this work is to visualize inheritance in object-oriented
	programs to help its comprehension. We propose a single, compact
	view of all class hierarchies at once using a custom Sunburst layout.
	It enables to quickly discover interesting facts across classes while
	preserving the essential relationship between parent and children
	classes. We explain how standard inheritance metrics are mapped into
	our visualization. Additionally, we define a new metric characterizing
	similar children classes. Using these metrics and the proposed layout,
	a set of common visual patterns is derived. These patterns allow
	the programmer to quickly understand how inheritance is used and
	provide answers to some essential questions when performing program
	comprehension tasks. Our approach is evaluated through a case study
	that involves examples from large programs, demonstrating its scalability.},
  crossref = {ESEM2009},
  doi = {10.1109/ESEM.2009.5316016}
}

@INPROCEEDINGS{Dix2000,
  author = {Alan Dix and Russell Beale and Andy Wood},
  title = {Architectures to make simple visualisations using simple systems},
  pages = {51--60},
  abstract = {In previous work, the first author argued for simple lightweight visualisations.
	These are surprisingly complex to produce due to the need for infrastructure
	to read files, etc. onCue, a desktop 'agent', aids the rapid production
	of such visualisations and their integration with desktop and Internet
	applications. Two examples are used dancing histograms for 2D tables
	and pieTrees for hierarchical numeric data. A major focus is the
	importance of architecture, both that of onCue itself and the underlying
	component infrastructure on which it is built - separation of concerns,
	mixed initiative computation and plug-and-play components lead to
	easily produced and easily used systems.},
  crossref = {AVI2000},
  doi = {10.1145/345513.345250}
}

@INPROCEEDINGS{Dmitrieva2009,
  author = {Julia Dmitrieva and Fons J. Verbeek},
  title = {Node-Link and Containment Methods in Ontology Visualization},
  abstract = {OWL Ontology language can be very expressive. This could provide difficulty
	in ontology understanding process. We belief, that an ontology visualization
	equipped with intuitive interactions can simplify this process, and
	help the user during ontology exploration and development. We introduce
	an approach representing an ontology with two different tree visualization
	techniques: the node-link technique, and the containment technique.
	These two representations show the structure of an ontology differently.
	The former, represents an ontology as a graph structure. This graph
	structure, based on the ontology hierarchy and properties, can be
	explored in different geometries: Euclidean, hyperbolic and spherical.
	The second representation shows only the hierarchical structure.
	The design of the containment approach is implemented in a non-standard
	way. In place of traditional two-dimensional space-filling techniques,
	we elaborate on the sphere-packing approach and make our hierarchy
	visualization three-dimensional. We augment this technique with the
	semantic zoom functionality, where the level of detail is a function
	of a distance from the viewer.},
  crossref = {OWLED2009},
  url = {http://ceur-ws.org/Vol-529/owled2009_submission_9.pdf}
}

@INPROCEEDINGS{Draper2008,
  author = {Geoffrey M. Draper and Richard F. Riesenfeld},
  title = {Interactive Fan Charts: A Space-Saving Technique for Genealogical
	Graph Exploration},
  abstract = {Fan charts are a popular method for displaying family trees in a compact
	way. We extend the concept of fan charts to include a number of interactive
	metaphors, thus transforming what was a static display medium into
	an interactive tool for browsing and editing genealogical data.},
  crossref = {FHTW2008},
  url = {http://fht.byu.edu/prev_workshops/workshop08/papers/1/1-1.pdf}
}

@INPROCEEDINGS{Duncan2010,
  author = {Christian A. Duncan and David Eppstein and Michael T. Goodrich and
	Stephen G. Kobourov and Martin N\"ollenburg},
  title = {Drawing Trees with Perfect Angular Resolution and Polynomial Area},
  pages = {183--194},
  abstract = {We study methods for drawing trees with perfect angular resolution,
	i.e., with angles at each vertex, v, equal to $2\pi /d(v)$. We show:
	1.Any unordered tree has a crossing-free straight-line drawing with
	perfect angular resolution and polynomial area. 2. There are ordered
	trees that require exponential area for any crossing-free straight-line
	drawing having perfect angular resolution. 3. Any ordered tree has
	a crossing-free Lombardi-style drawing (where each edge is represented
	by a circular arc) with perfect angular resolution and polynomial
	area. Thus, our results explore what is achievable with straight-line
	drawings and what more is achievable with Lombardi-style drawings,
	with respect to drawings of trees with perfect angular resolution.},
  crossref = {GD2010},
  doi = {10.1007/978-3-642-18469-7_17}
}

@INPROCEEDINGS{Dwyer2010,
  author = {Tim Dwyer and Kim Marriott and Peter Sbarski},
  title = {{Hi-Tree} Layout Using Quadratic Programming},
  pages = {212--219},
  abstract = {Horizontal placement of nodes in tree layout or layered drawings of
	directed graphs can be modelled as a convex quadratic program. Thus,
	quadratic programming provides a declarative framework for specifying
	such layouts which can then be solved optimally with a standard quadratic
	programming solver. While slower than specialized algorithms, the
	quadratic programming approach is fast enough for practical applications
	and has the great benefit of being flexible yet easy to implement
	with standard mathematical software. We demonstrate the utility of
	this approach by using it to layout hi-trees. These are a tree-like
	structure with compound nodes recently introduced for visualizing
	the logical structure of arguments and of decisions.},
  crossref = {DIAGRAMS2010},
  doi = {10.1007/978-3-642-14600-8_20}
}

@INPROCEEDINGS{Eades1992a,
  author = {Peter Eades and Tao Lin and Xuemin Lin},
  title = {Minimum size h-v drawings},
  pages = {386--394},
  abstract = {Trees are one of the most commonly used structures in computing, and
	many techniques for the visualization of trees are available. These
	techniques usually aim to find an aestetically pleasing layout for
	a tree on a screen of limited size. This paper presents an algorithm
	for "h-v tree" drawing. The algorithm can be used to find a drawing
	of minimal "size", where "size" has a variety of definitions (inclusing
	area). Two applications of the algorithm are explicitly presented.},
  crossref = {AVI1992},
}

@INPROCEEDINGS{Etemad2009,
  author = {Katayoon Etemad and Sheelagh Carpendale},
  title = {{ShamsehTrees}: Providing Hierarchical Context for Nodes of Interest},
  pages = {293--300},
  abstract = {Visualizations of hierarchical data usually focus on conveying structure.
	However, with really large hierarchies, layouts tend to become overcrowded,
	making it difficult to see details about specific nodes. In contrast,
	ShamsehTrees focus on layouts centered on a node of interest, provide
	interactive nested layouts that were inspired by artistic and natural
	floral patterns, and make use of the natural symmetries in phyllotactic
	patterns. Instead of emphasizing overall tree structure, these layouts
	are created to make the most space available for the node of interest.
	The basic layout is comprised of nested circles that are centered
	on the node of interest. After selecting a new node of interest,
	the resizing and repositioning of nodes is animated as they transition
	to the new layout.},
  crossref = {Bridges2009}
}

@INPROCEEDINGS{Fahrenholtz1995,
  author = {Dietrich Fahrenholtz and Volker Haarslev},
  title = {Visualization of {Strand}\texttrademark ~processes},
  pages = {114--115},
  abstract = {The paper describes a visualization tool that uses polar coordinates
	to create a circular shaped layout of large call trees of Strand
	programs. Due to the enormous amount of processes which are generated
	during execution of parallel Strand programs, conventional techniques
	to display call trees are over-charged. Because of this the tool
	`Polaranimation' was developed and implemented. One of its prominent
	features is the ability to display the complete call tree without
	loosing any vital information. Additionally, it provides debugging
	facilities and supports the performance tuning of parallel programs.
	A number of Strand programs have been written and a performance evaluation
	and comparison guided by `Polaranimation' was conducted.},
  crossref = {VL1995},
  doi = {10.1109/VL.1995.520793}
}

@INCOLLECTION{Feinberg2010,
  author = {Jonathan Feinberg},
  title = {Wordle},
  chapter = {3},
  pages = {37--58},
  crossref = {Steele2010},
  url = {http://static.mrfeinberg.com/bv_ch03.pdf}
}

@INPROCEEDINGS{Ganascia2004,
  author = {Jean-Gabriel Ganascia},
  title = {{RECIT}: REpr\'esentation Cartographique et Insulaire de Textes},
  pages = {59--70},
  abstract = {Experiences show that most readers are lost in electronic text, because
	they lack of global information. As a consequence, many people print
	electronic texts before reading them. This strange phenomenon was
	not predicted in the past and it could preclude the expansion of
	electronic reading. We propose here a way to provide some visualization
	of the structure of the document. That corresponds to the cartography
	of its overall organization. Our hope is that it could help to orient
	in electronic texts and consequently to facilitate electronic reading.
	This paper describes the origins of difficulties and then it presents
	all the technical details of the proposed solution.},
  crossref = {CIFT2004},
  url = {http://hal.archives-ouvertes.fr/docs/00/06/25/35/PDF/sic_00001258.pdf}
}

@INPROCEEDINGS{Ganascia2006,
  author = {Jean-Gabriel Ganascia},
  title = {AC$^3$ - Automatic Cartography of Cultural Contents},
  pages = {253--263},
  abstract = {Experiences with e-books show that the principle obstacle to electronic
	reading is neither the weight, nor the autonomy or the discomfort
	of reading on screen, but the absence of reference mark which makes
	it possible to replace the current window of reading in the whole
	of the book. We present an automatic cartography of electronic documents
	which constitutes an attempt to facilitate navigation, reading and
	memorization of contents. It is to automatically build a singular
	picture which is designed to be associated to our remembering of
	each document, i.e. to our mental image. This picture corresponds
	to the cartography of an island. Its shape is build from the document
	structure; its coloring reflects the affective content of the text
	extracted by keywords spotting techniques while icons associated
	to document topics are added to textual legends as in ancient geographical
	maps.},
  crossref = {VIEW2006},
  doi = {10.1007/978-3-540-71027-1_22}
}

@INPROCEEDINGS{Granitzer2004,
  author = {Michael Granitzer and Wolfgang Kienreich and Vedran Sabol and Keith
	Andrews and Werner Klieber},
  title = {Evaluating a System for Interactive Exploration of Large, Hierarchically
	Structured Document Repositories},
  pages = {127--134},
  abstract = {The InfoSky visual explorer is a system enabling users to interactively
	explore large, hierarchically structured document collections. Similar
	to a real-world telescope, InfoSky employs a planar graphical representation
	with variable magnification. Documents of similar content are placed
	close to each other and displayed as stars, while collections of
	documents at a particular level in the hierarchy are visualised as
	bounding polygons. Usability testing of an early prototype implementation
	of InfoSky revealed several design issues which prevented users from
	fully exploiting the power of the visual metaphor. Evaluation results
	have been incorporated into an advanced prototype, and another usability
	test has been conducted. A comparison of test results demonstrates
	enhanced system performance and points out promising directions for
	further work.},
  crossref = {INFOVIS2004},
  doi = {10.1109/INFVIS.2004.19}
}

@INPROCEEDINGS{Grivet2004,
  author = {S\'ebastien Grivet and David Auber and Jean-Philippe Domenger and
	Guy Melan\c{c}on},
  title = {Bubble Tree Drawing Algorithm},
  pages = {633--641},
  abstract = {In this paper, we present an algorithm, called Bubble Tree, for the
	drawing of general rooted trees. A large variety of algorithms already
	exists in this field. However, the goal of this algorithm is to obtain
	a better drawing which makes a trade off between the angular resolution
	and the length of the edges. We show that the Bubble Tree drawing
	algorithm provides a planar drawing with at most one bend per edge
	in linear running time.},
  crossref = {ICCVG2004},
  doi = {10.1007/1-4020-4179-9_91}
}

@INPROCEEDINGS{Husken2007,
  author = {Peter H\"usken and J\"urgen Ziegler},
  title = {Degree-of-Interest Visualization for Ontology Exploration},
  pages = {116--119},
  abstract = {In recent years, improvements in semantic web technologies have given
	us new expressive description languages for modeling knowledge domains
	— the so called ontologies. Nevertheless, ontology editors lack of
	easy and intuitive user interfaces, so that the exploration and creation
	of ontologies is often too difficult to be efficient. In this short
	paper, we introduce a new tree widget which utilizes sophisticated
	visualization and interaction features for ontology exploration and
	editing as a work in progress study. Due to space limitations we
	co+ncentrate here on the aspect of ontology browsing.},
  crossref = {INTERACT2007},
  doi = {10.1007/978-3-540-74796-3_12}
}

@INPROCEEDINGS{Ham2002,
  author = {Frank van Ham and Jarke J. van Wijk},
  title = {Beamtrees: Compact Visualization of Large Hierarchies},
  pages = {93--100},
  abstract = {Beamtrees are a new method for the visualization of large hierarchical
	data sets. Nodes are shown as stacked circular beams, such that both
	the hierarchical structure as well as the size of nodes are depicted.
	The dimensions of beams are calculated using a variation of the treemap
	algorithm. A small user study indicated that beamtrees are significantly
	more effective than nested treemaps and cushion treemaps for the
	extraction of global hierarchical information.},
  crossref = {INFOVIS2002},
  doi = {10.1109/INFVIS.2002.1173153}
}

@INPROCEEDINGS{Hao2007a,
  author = {Jie Hao and Kang Zhang},
  title = {A Mobile Interface for Hierarchical Information Visualization and
	Navigation},
  abstract = {There is a dramatic increase in the population who use mobile computing
	devices. Though the hardware becomes more powerful, effective support
	for information rendering on small screens very much lags behind.
	To display hierarchical information, researchers have proposed many
	algorithms for desktop screen visualization. Such algorithms are
	generally divided into connection and enclosure. Connection approach
	displays hierarchy with a clear structure but consume display area.
	Enclosure can maximally utilize the screen space but the layout is
	essentially implicit. This paper describes a new Radial Edgeless
	Tree (RELT) for visualizing hierarchical data on palm sized devices.
	The aim of RELT is to combine the advantages of connection and enclosure
	approaches. By recursively partitioning the display area, this technique
	maximizes the space usage. The structural clarity of layout can be
	reached by arranging location of non-overlapping regions. RELT can
	be adapted for visualizing structural information for various applications.},
  crossref = {ISCE2007},
  doi = {10.1109/ISCE.2007.4382214}
}

@INPROCEEDINGS{Hao2009,
  author = {Jie Hao and Kang Zhang and Chad Allen Gabrysch and Qiaoming Zhu},
  title = {Managing Hierarchical Information on Small Screens},
  pages = {429--441},
  abstract = {This paper presents a visualization methodology called Radial Edgeless
	Tree (RELT) for visualizing and navigating hierarchical information
	on mobile interfaces. RELT is characterized by recursive division
	of a polygonal display area, space-filling, maximum screen space
	usage, and clarity of the hierarchical structure. It is also general
	and flexible enough to allow users to customize the root location
	and stylize the layout. The paper presents the general RELT drawing
	algorithm that is adaptable and customizable for different applications.
	We demonstrate the algorithm's application for stock market visualization,
	and also present an empirical study on an emulated implementation
	with a currently used cell phone interface in terms of their performances
	in finding desired information.},
  crossref = {APWEB2009},
  doi = {10.1007/978-3-642-00672-2_38}
}

@INPROCEEDINGS{Hao2007,
  author = {Jie Hao and Kang Zhang and Mao Lin Huang},
  title = {{RELT} -- Visualizing Trees on Mobile Devices},
  pages = {344--357},
  abstract = {The small screens on increasingly used mobile devices challenge the
	traditional visualization methods designed for desktops. This paper
	presents a method called "Radial Edgeless Tree" (RELT) for visualizing
	trees in a 2-dimensional space. It combines the existing connection
	tree drawing with the space-filling approach to achieve the efficient
	display of trees in a small geometrical area, such as the screen
	that are commonly used in mobile devices. We recursively calculate
	a set of non-overlapped polygonal nodes that are adjacent in the
	hierarchical manner. Thus, the display space is fully used for displaying
	nodes, while the hierarchical relationships among the nodes are presented
	by the adjacency (or boundary-sharing) of the nodes. It is different
	from the other traditional connection approaches that use a node-link
	diagram to present the parent-child relationships which waste the
	display space. The hierarchy spreads from north-west to south-east
	in a top-down manner which naturally follows the traditional way
	of human perception of hierarchies. We discuss the characteristics,
	advantages and limitations of this new technique and suggestions
	for future research.},
  crossref = {VISUAL2007},
  doi = {10.1007/978-3-540-76414-4_34}
}

@INPROCEEDINGS{Harel2000,
  author = {David Harel and Gregory Yashchin},
  title = {An algorithm for blob hierarchy layout},
  pages = {29--40},
  abstract = {We present an algorithm for the aesthetic drawing of basic hierarchical
	blob structures, of the kind found in higraphs and statecharts and
	in other diagrams in which hierarchy is depicted as topological inclusion.
	Our work could also be useful in window system dynamics, and possibly
	also in things like newspaper layout, etc. Several criteria for aesthetics
	are formulated, and we discuss their motivation, our methods of implementation
	and the algorithm's performance.},
  crossref = {AVI2000},
  doi = {10.1145/345513.345240}
}

@INPROCEEDINGS{Heer2004,
  author = {Jeffrey Heer and Stuart K. Card},
  title = {{DOITrees} Revisited: Scalable, Space-Constrained Visualization of
	Hierarchical Data},
  pages = {421--424},
  abstract = {This paper extends previous work on focus+context visualizations of
	tree-structured data, introducing an efficient, space-constrained,
	multi-focal tree layout algorithm (TreeBlock) and techniques at both
	the system and interactive levels for dealing with scale. These contributions
	are realized in a new version of the Degree-Of-Interest Tree browser,
	supporting real-time interactive visualization and exploration of
	data sets containing on the order of a million nodes.},
  crossref = {AVI2004},
  doi = {10.1145/989863.989941}
}

@INPROCEEDINGS{Herman1999,
  author = {Ivan Herman and Scott Marshall and Guy Melan\c{c}on and David J.
	Duke and Maylis Delest and Jean-Philippe Domenger},
  title = {Skeletal images as visual cues in graph visualization},
  pages = {13--22},
  abstract = {The problem of graph layout and drawing is fundamental to many aproaches
	to the visualization of relational information structures. As the
	data set grows, the visualization problem is compounded by the need
	to reconcile the user's need for orientation cues with the danger
	of information overload. Put simply: How can we limit the number
	of visual elements on the screen so as not to overwhelm the user
	yet retain enough information that the user is able to navigate and
	explore the data set confidently? How can we provide orientational
	cues so that a user can understand the location of the current viewpoint
	in a large data set? These are problems inherent not only to graph
	drawing but information visualization in general. We propose a method
	which extracts the significant features of a directed acyclic graph
	as the basis for navigation},
  crossref = {VISSYM1999},
  url = {http://diglib.eg.org/EG/DL/WS/VisSym99/Herman.pdf}
}

@INPROCEEDINGS{Herman1999a,
  author = {Ivan Herman and Guy Melan\c{c}on and Maurice M. de Ruiter and Maylis
	Delest},
  title = {Latour -- A Tree Visualisation System},
  pages = {392--399},
  abstract = {This paper presents some of the most important features of a tree
	visualisation system called Latour, developed for the purposes of
	information visualisation. This system includes a number of interesting
	and unique characteristics, for example the provision for visual
	cues based on complexity metrics on graphs, which represent general
	principles that, in our view, graph based information visualisation
	systems should generally offer.},
  crossref = {GD1999},
  doi = {10.1007/3-540-46648-7_40}
}

@INPROCEEDINGS{Holten2005,
  author = {Danny Holten and Roel Vliegen and Jarke J. van Wijk},
  title = {Visual Realism for the Visualization of Software Metrics},
  pages = {27--32},
  abstract = {The visualization techniques used in current software visualization
	frameworks make use of a limited set of graphical elements to highlight
	relevant aspects of a software system. Typical examples of such elements
	are text, simple geometric shapes and uniform color fills. Although
	human visual perception enables rapid processing of additional visual
	cues like shading and texture, they are not used. We contend that
	such 2D and 3D computer graphics techniques for achieving visual
	realism can be used to increase the information throughput of software
	visualization techniques. Visualization results are presented to
	show how treemaps, cushions, color, texture, and bump mapping can
	be used to visualize software metrics of hierarchically organized
	elements of a software system},
  crossref = {VISSOFT2005},
  doi = {10.1109/VISSOF.2005.1684299}
}

@INPROCEEDINGS{Hong2003,
  author = {Seok-Hee Hong and Tom Murtagh},
  title = {{PolyPlane}: An Implementation of a New Layout Algorithm For Trees
	In Three Dimensions},
  pages = {90--91},
  crossref = {INFOVISposter2003}
}

@INPROCEEDINGS{Horn2009,
  author = {Michael S. Horn and Matthew Tobiasz and Chia Shen},
  title = {Visualizing Biodiversity with {Voronoi} Treemaps},
  pages = {265--270},
  abstract = {Introduced in 2005, the Voronoi treemap algorithm is an information
	visualization technique for displaying hierarchical data. Voronoi
	treemaps use weighted, centroidal Voronoi diagrams to create a nested
	tessellation of convex polygons. However, despite appealing qualities,
	few real world examples of Voronoi treemaps exist. In this paper,
	we present a multi-touch tabletop application called Involv that
	uses the Voronoi treemap algorithm to create an interactive visualization
	for the Encyclopedia of Life. Involv is the result of a year-long
	iterative development process and includes over 1.2 million named
	species organized in a nine-level hierarchy. Working in the domain
	of life sciences, we have encountered the need to display supplemental
	hierarchical data to augment information in the treemap. Thus we
	propose an extension of the Voronoi treemap algorithm that employs
	force-directed graph drawing techniques both to guide the construction
	of the treemap and to overlay a supplemental hierarchy.},
  crossref = {ISVD2009},
  doi = {10.1109/ISVD.2009.22}
}

@INPROCEEDINGS{Huang2009,
  author = {Mao Lin Huang and Tze-Haw Huang and Jiawan Zhang},
  title = {{TreemapBar}: Visualizing Additional Dimensions of Data in Bar Chart},
  pages = {98--103},
  abstract = {Bar chart is a very common and simple graph that is mainly used to
	visualize simple x, y plots of data for numerical comparisons by
	partitioning the categorical data values into bars and typically
	limited to operate on highly aggregated dataset. In today's growing
	complexity of business data with multi dimensional attributes using
	bar chart itself is not sufficient to deal with the representation
	of such business dataset and it also not utilizes the screen space
	efficiently.Nevertheless, bar chart is still useful because of its
	shape create strong visual attention to users at first glance than
	other visualization techniques. In this article, we present a treemap
	bar chart + tablelens interaction technique that combines the treemap
	and bar chart visualizations with a tablelens based zooming technique
	that allows users to view the detail of a particular bar when the
	density of bars increases. In our approach, the capability of the
	original bar chart and treemaps for representing complex business
	data is enhanced and the utilization of display space is also optimized.},
  crossref = {IV2009},
  doi = {10.1109/IV.2009.22}
}

@INPROCEEDINGS{Huang2007,
  author = {Mao Lin Huang and Quang Vinh Nguyen and Wei Lai and Xiaodi Huang},
  title = {Three-Dimensional {EncCon} Tree},
  pages = {429--433},
  abstract = {This paper describes a three-dimensional extension of a enclosure+connection
	layout technique, called EncCon tree. The three-dimensional visualization
	includes layout and navigation. The layout algorithm directly generalizes
	the two-dimensional EncCon tree layout algorithm to three-dimensional
	space in which nodes at the same level of the hierarchy are placed
	onto the same plane. The interactive navigation uses standard three-dimensional
	viewing techniques which include view transformation, rotation and
	zoom.},
  crossref = {CGIV2007},
  doi = {10.1109/CGIV.2007.82}
}

@INPROCEEDINGS{Ishihara2006,
  author = {Masaki Ishihara and Kazuo Misue and Jiro Tanaka},
  title = {Ripple Presentation for Tree Structures with Historical Information},
  pages = {153--160},
  abstract = {We propose a new method for representing tree structures with historical
	information. We call this method Ripple Presentation. Categories
	of nodes are represented by the angles of edges and elapsed time
	is represented by the length of the edges. In this way, the method
	can express both the time series and categories, which has been diffic
	lt to achieve with either tree structures or lists. As a result,
	users can nderstand the overall information from their viewpoint
	view and discover target information effectively. We applied the
	method to trackback links of Weblog articles and the latest articles
	of News sites using RSS on Web as a resource.},
  crossref = {APVIS2006},
  url = {http://portal.acm.org/citation.cfm?id=1151903.1151927}
}

@INPROCEEDINGS{Jeong1998,
  author = {Chang-Sung Jeong and Alex Pang},
  title = {Reconfigurable Disc Trees for Visualizing Large Hierarchical Information
	Space},
  pages = {19--25},
  abstract = {We present a new visualization technique, called RDT (Reconfigurable
	Disc Tree) which can alleviate the disadvantages of cone trees significantly
	for large hierarchies while maintaining its context of using 3D depth.
	In RDT, each node is associated with a disc around which its children
	are placed. Using discs instead of cones as the basic shape in RDT
	has several advantages: significant reduction of occluded region,
	sharp increase in number of displayed nodes, and easy projection
	onto plane without visual overlapping. We show that RDT can greatly
	enhance user perception by transforming its shapes dynamically in
	several ways:(1) disc tree which can significantly reduce the occluded
	region by the foreground objects, (2) compact disc tree which can
	increase the number of nodes displayed on the screen, and (3) plane
	disc tree which can be mapped onto the plane without visual overlapping.
	We describe an implementation of our visualization system called
	VISIT (Visual Information System for reconfigurable dIsc Tree). It
	provides 2D and 3D layouts for RDT and various user interface features
	such as tree reconfiguration, tree transformation, tree shading,
	viewing transformation, animation, selection and browsing which can
	enhance the user perception and navigation capabilities. We also
	evaluate our system using the following three metrics: percentage
	of occlusion, density of displayed nodes on a screen. number of identifiable
	nodes.},
  crossref = {INFOVIS1998},
  doi = {10.1109/INFVIS.1998.729555}
}

@INPROCEEDINGS{Jia2010,
  author = {Ming Jia and Ling Li and Erin Boggess and Eve Syrkin Wurtele and
	Julie A. Dickerson},
  title = {Visualizing Multivariate Hierarchic Data Using Enhanced Radial Space-Filling
	Layout},
  pages = {350--360},
  abstract = {Currently, visualization tools for large ontologies (e.g., pathway
	and gene ontologies) result in a very flat wide tree that is difficult
	to fit on a single display. This paper develops the concept of using
	an enhanced radial space-filling (ERSF) layout to show biological
	ontologies efficiently. The ERSF technique represents ontology terms
	as circular regions in 3D. Orbital connections in a third dimension
	correspond to non-tree edges in the ontology that exist when an ontology
	term belongs to multiple categories. Biologists can use the ERSF
	layout to identify highly activated pathway or gene ontology categories
	by mapping experimental statistics such as coefficient of variation
	and overrepresentation values onto the visualization. This paper
	illustrates the use of the ERSF layout to explore pathway and gene
	ontologies using a gene expression dataset from E. coli.},
  crossref = {ISVC2010},
  doi = {10.1007/978-3-642-17289-2_34}
}

@INPROCEEDINGS{Jia2009,
  author = {Ming Jia and Sivakumar Swaminathan and Eve Syrkin Wurtele and Julie
	Dickerson},
  title = {{MetNetGE}: Visualizing Biological Networks in Hierarchical Views
	and {3D} Tiered Layouts},
  pages = {287--294},
  abstract = {Linking experimental data with large-scale biomedical networks is
	key for achieving new discoveries in system biology research. Visualization
	tools that facilitate these tasks often result in a dense Web of
	connections that resembles a tangled hairball and is difficult to
	interpret. MetNetGE is an interactive pathway navigation tool based
	on Google Earth that features novel visualization techniques for
	pathway information display. Instead of simply showing all the pathways
	in a network in a complex graph, MetNetGE visualizes the entire network
	of pathways based on the hierarchical pathway ontology using a novel
	radial space filling (RSF) method. Orbits show when pathways belong
	to multiple categories. Mapping cumulative experiment statistics
	on the RSF drawing aids biologists in easily identifying highly activated
	pathways in an experiment. After identifying key pathways, biologists
	can fly to the corresponding region and see the detailed pathway
	and experimental data in an aligned 3D tiered layout with simplified
	cross-layer connection patterns.},
  crossref = {BIBMW2009},
  doi = {10.1109/BIBMW.2009.5332109}
}

@INPROCEEDINGS{Johnson1992,
  author = {Brian Johnson},
  title = {TreeViz: Treemap visualization of hierarchically structured information},
  pages = {369--370},
  abstract = {TreeViz is an Apple Macintosh implementation of the treemap technique
	for visualizing hierarchical information structures. TreeViz enables
	users to visualize and browse large hierarchically structured information
	spaces. TreeViz enables the drawing of hierarchies an order of magnitude
	larger (number of nodes) than is possible with typical presentation
	methods, given the same display space.},
  crossref = {CHI1992},
  doi = {10.1145/142750.142833}
}

@INPROCEEDINGS{Johnson1991,
  author = {Brian Johnson and Ben Shneiderman},
  title = {{Tree-Maps}: A space-filling approach to the visualization of hierarchical
	information structures},
  pages = {284--291},
  abstract = {A method for visualizing hierarchically structured information is
	described. The tree-map visualization technique makes 100% use of
	the available display space, mapping the full hierarchy onto a rectangular
	region in a space-filling manner. This efficient use of space allows
	very large hierarchies to be displayed in their entirety and facilitates
	the presentation of semantic information. Tree-maps can depict both
	the structure and content of the hierarchy. However, the approach
	is best suited to hierarchies in which the content of the leaf nodes
	and the structure of the hierarchy are of primary importance, and
	the content information associated with internal nodes is largely
	derived from their children.},
  crossref = {VIS1991},
  doi = {10.1109/VISUAL.1991.175815}
}

@INPROCEEDINGS{Joshi2004,
  author = {Jyoti Joshi and Brendan Cleary and Chris Exton},
  title = {Application of Helix Cone Tree Visualizations to Dynamic Call Graph
	Illustration},
  pages = {68--75},
  abstract = {We describe a tool that enables users to record and visualise runtime
	behaviour of software applications developed in Java. The execution
	trace, stored in the form of an XML file is visualized using 3D call
	graphs that are an extension of the Cone Tree information visualisation
	technique. This tool gives the user the ability to create several
	call graph views from a program's execution trace, providing additional
	representations of the program execution to both novice and expert
	programmers for the purposes of program execution analysis.},
  crossref = {ProVis2004},
  url = {http://www.dcs.warwick.ac.uk/pvw04/p10.pdf}
}

@INPROCEEDINGS{Kappe2003,
  author = {Frank Kappe and Georg Droschl and Wolfgang Kienreich and Vedran Sabol
	and Jutta Becker and Keith Andrews and Michael Granitzer and Klaus
	Tochtermann and Peter Auer},
  title = {{InfoSky}: Visual Exploration of Large Hierarchical Document Repositories},
  pages = {1268--1272},
  crossref = {HCII2003},
  url = {http://www.worldcat.org/title/human-centred-computing-cognitive-social-and-ergonomic-aspects/oclc/249275186}
}

@INPROCEEDINGS{Kerr2003,
  author = {Bernard Kerr},
  title = {Thread Arcs: An email thread visualization},
  pages = {211--218},
  abstract = {This paper describes Thread Arcs, a novel interactive visualization
	technique designed to help people use threads found in email. Thread
	Arcs combine the chronology of messages with the branching tree structure
	of a conversational thread in a mixed-model visualization by Venolia
	and Neustaedter (2003) that is stable and compact. By quickly scanning
	and interacting with Thread Arcs, people can see various attributes
	of conversations and find relevant messages in them easily. We tested
	this technique against other visualization techniques with users'
	own email in a functional prototype email client. Thread Arcs proved
	an excellent match for the types of threads found in users' email
	for the qualities users wanted in small-scale visualizations.},
  crossref = {INFOVIS2003},
  doi = {10.1109/INFVIS.2003.1249028}
}

@INPROCEEDINGS{Keskin1997,
  author = {Can Keskin and Volker Vogelmann},
  title = {Effective Visualization of Hierarchical Graphs With the Cityscape
	Metaphor},
  pages = {52--57},
  abstract = {In this paper, we describe an implementation of the cityscape metaphor
	to visualize trees. The cityscape metaphor is a generalization of
	barcharts in 3D. Our approach serves for better exploitation of human
	perception capabilities. To achieve this we employ effective visual
	cues like node position and size. We determine node positions in
	terms of perceptual organization. Further we determine node sizes
	for providing redundant hierarchical information. Redundancy aides
	in better understanding the tree structure. Finally, we point out
	some of the advantages of this approach to other spatial metaphors
	such as cone trees.},
  crossref = {NPIVM1997},
  doi = {10.1145/275519.275531}
}

@INPROCEEDINGS{Kienreich2003,
  author = {Wolfgang Kienreich and Vedran Sabol and Michael Granitzer and Frank
	Kappe and Keith Andrews},
  title = {{InfoSky}: A System for Visual Exploration of Very Large, Hierarchically
	Structured Knowledge Spaces},
  abstract = {This publication presents InfoSky, a system enabling exploration of
	large, hierarchically structured knowledge spaces. InfoSky employs
	a two-dimensional graphical representation with variable magnification,
	much like a real-world telescope, to visualise individual documents
	as stars, hierarchical structures as constellations, and the whole
	knowledge repository as a galaxy. Force-directed placement is used
	to position topically similar documents in geometric adjacency, and
	modified Voronoi diagrams are employed to construct non-overlapping
	constellation boundaries, while statistical text processing extracts
	abstracts and keywords from documents and collections. InfoSky combines
	hierarchy and topical similarity in a visualisation using a striking,
	well-known metaphor, providing users with a tool appropriate for
	today’s large, hierarchically structured document repositories.},
  crossref = {FGWM2003},
  url = {http://km.aifb.kit.edu/ws/LLWA/fgwm/Resources/FGWM03_02_Wolfgang_Kienreich.pdf}
}

@INPROCEEDINGS{Kleiberg2001,
  author = {Ernst Kleiberg and Huub van de Wetering and Jarke J. van Wijk},
  title = {Botanical Visualization of Huge Hierarchies},
  pages = {87--94},
  abstract = {A new method for the visualization of huge hierarchical data structures
	is presented. The method is based on the observation that we can
	easily see the branches, leaves, and their arrangement in a botanical
	tree, despite of the large number of elements. The strand model of
	Holton is used to convert an abstract tree into a geometric model.
	Nonleaf nodes are mapped to branches and child nodes to subbranches.
	A naive application of this model leads to unsatisfactory results,
	hence it is tailored to suit our purposes better. Continuing branches
	are emphasized, long branches are contracted, and sets of leaves
	are shown as fruit. The method is applied to the visualization of
	directory structures. The elements, directories and files, as well
	as their relations can easily be extracted, thereby showing that
	the use of methods from botanical modeling can be effective for information
	visualization.},
  crossref = {INFOVIS2001}
}

@INPROCEEDINGS{Koike1993,
  author = {Hideki Koike and Hirotaka Yoshihara},
  title = {Fractal Approaches for Visualizing Huge Hierarchies},
  pages = {55--60},
  abstract = {This paper describes fractal approaches to the problems which associate
	with visualizing huge hierarchies. The geometrical characteristic
	of a fractal, self-similarity, allows users to visually interact
	with a huge tree in the same manner at every level of the tree. The
	fractal dimension, a measure of complexity, makes it possible to
	control the total amount of displayed nodes. A prototype visualization
	system for UNIX directories is also shown.},
  crossref = {VL1993},
  doi = {10.1109/VL.1993.269566}
}

@INPROCEEDINGS{Kreuseler1999,
  author = {Matthias Kreuseler and Heidrun Schumann},
  title = {Information visualization using a new focus+context technique in
	combination with dynamic clustering of information space},
  pages = {1--5},
  abstract = {This paper presents work in progress on our approach to visualizing
	multi-dimensional and hierarchical information. We propose two new
	graphical user interfaces, the Magic Eye View (MEV) and ShapeVis
	to explore information spaces. In order to cope with large information
	sets we combine MEV and ShapeVis with dynamic hierarchical clustering
	of information units The Magic Eye View, which implements a new Focus+Context
	technique, is used as the interface for visualizing those hierarchies.
	In order to support detailed exploration of the information space
	(e.g analysis of certain cluster nodes or hierarchy levels) a new
	technique for visualizing multidimensional information is used. ShapeVis
	provides 2D or 3D representations of the information objects according
	to the selected subset of the information space Objects are represented
	as small closed free-form-surfaces. The location, size and shape
	of these surfaces describe the original objects in the information
	space uniquely according to their properties.},
  crossref = {NPIV1999},
  doi = {10.1145/331770.331772}
}

@INPROCEEDINGS{Kubota2006,
  author = {Hidekazu Kubota and Toyoaki Nishida and Yasuyuki Sumi},
  title = {Visualization of Contents Archive by Contour Map Representation},
  pages = {19--32},
  abstract = {This article describes a model for sustainable contents management,
	its visualization algorithms, and the implemented system, called
	sustainable knowledge globe (SKG). The focal point of our study is
	visualization using contour maps. The graphical representation of
	tree-structured contents increases in complexity with the number
	of contents. The contour map representations can briefly depict the
	arrangement and structure of contents in an archive. Three contour
	map representations are proposed assuming the importance of the arrangement
	design. Nesting, dendroidal, and island-like contours are amplified
	from the viewpoint of preservation of the structures and arrangements,
	in addition to supporting shape and texture design. The comparison
	and applications of the three algorithms are discussed.},
  crossref = {JSAI2006},
  doi = {10.1007/978-3-540-69902-6_3}
}

@INPROCEEDINGS{Lu2008,
  author = {Hao R. L\"u and James Fogarty},
  title = {Cascaded {Treemaps}: Examining the Visibility and Stability of Structure
	in {Treemaps}},
  pages = {259--266},
  abstract = {Treemaps are an important and commonly-used approach to hierarchy
	visualization, but an important limitation of treemaps is the difficulty
	of discerning the structure of a hierarchy. This paper presents cascaded
	treemaps, a new approach to treemap presentation that is based in
	cascaded rectangles instead of the traditional nested rectangles.
	Cascading uses less space to present the same containment relationship,
	and the space savings enable a depth effect and natural padding between
	siblings in complex hierarchies. In addition, we discuss two general
	limitations of existing treemap layout algorithms: disparities between
	node weight and relative node size that are introduced by layout
	algorithms ignoring the space dedicated to presenting internal nodes,
	and a lack of stability when generating views of different levels
	of treemaps as a part of supporting interactive zooming. We finally
	present a two-stage layout process that addresses both concerns,
	computing a stable structure for the treemap and then using that
	structure to consider the presentation of internal nodes when arranging
	the treemap. All of this work is presented in the context of two
	large real-world hierarchies, the Java package hierarchy and the
	eBay auction hierarchy.},
  crossref = {GI2008},
  url = {http://portal.acm.org/citation.cfm?doid=1375714.1375758}
}

@INPROCEEDINGS{Lamping1996a,
  author = {John Lamping and Ramana Rao},
  title = {Visualizing large trees using the hyperbolic browser},
  pages = {388--389},
  abstract = {We demonstrate a focus+context (fisheye) scheme for visualizing and
	manipulating large hierarchies. Our approach is to lay out the hierarchy
	uniformly on the hyperbolic plane and map this plane onto a circular
	display region. The projection onto the disk provides a natural mechanism
	for assigning more space to a portion of the hierarchy while still
	embedding it in a much larger context. Change of focus is accomplished
	by translating the structure on the hyperbolic plane, which allows
	a smooth transition without compromising the presentation of the
	context.},
  crossref = {CHIcomp1996},
  doi = {10.1145/257089.257389}
}

@INPROCEEDINGS{Lamping1995,
  author = {John Lamping and Ramana Rao and Peter Pirolli},
  title = {A focus+context technique based on hyperbolic geometry for visualizing
	large hierarchies},
  pages = {401--408},
  abstract = {We present a new focus+context (fisheye) technique for visualizing
	and manipulating large hierarchies. Our technique assigns more display
	space to a portion of the hierarchy while still embedding it in the
	context of the entire hierarchy. The essence of this scheme is to
	lay out the hierarchy in a uniform way on a hyperbolic plane and
	map this plane onto a circular display region. This supports a smooth
	blending between focus and context, as well as continuous redirection
	of the focus. We have developed effective procedures for manipulating
	the focus using pointer clicks as well as interactive dragging, and
	for smoothly animating transitions across such manipulation. A laboratory
	experiment comparing the hyperbolic browser with a conventional hierarchy
	browser was conducted.},
  crossref = {CHI1995},
  doi = {10.1145/223904.223956}
}

@INPROCEEDINGS{Langelier2007,
  author = {Guillaume Langelier and Karim Dhambri},
  title = {Visual analysis of {Azureus} using {VERSO}},
  pages = {163--164},
  abstract = {In this challenge report, we will see how to use VERSO in order to
	analyse Azureus. We answer the challenge through two separate main
	goals which represent two possible tasks available in VERSO. The
	first task is design anomaly detection and the second task is evolution
	analysis.},
  crossref = {VISSOFT2007},
  doi = {10.1109/VISSOF.2007.4290720}
}

@INPROCEEDINGS{Langelier2005,
  author = {Guillaume Langelier and Houari Sahraoui and Pierre Poulin},
  title = {Visualization-based analysis of quality for large-scale software
	systems},
  pages = {214--223},
  abstract = {We propose an approach for complex software analysis based on visualization.
	Our work is motivated by the fact that in spite of years of research
	and practice, software development and maintenance are still time
	and resource consuming, and high-risk activities. The most important
	reason in our opinion is the complexity of many phenomena related
	to software, such as its evolution and its reliability. In fact,
	there is very little theory explaining them. Today, we have a unique
	opportunity to empirically study these phenomena, thanks to large
	sets of software data available through open-source programs and
	open repositories. Automatic analysis techniques, such as statistics
	and machine learning, are usually limited when studying phenomena
	with unknown or poorly-understood influence factors. We claim that
	hybrid techniques that combine automatic analysis with human expertise
	through visualization are excellent alternatives to them. In this
	paper, we propose a visualization framework that supports quality
	analysis of large-scale software systems. We circumvent the problem
	of size by exploiting perception capabilities of the human visual
	system.},
  crossref = {ASE2005},
  doi = {10.1145/1101908.1101941}
}

@INPROCEEDINGS{Larrea2007,
  author = {Martin L. Larrea and Sergio R. Martig and Silvia M. Castro},
  title = {Spherical Layout for {3D} Tree Visualization},
  pages = {91--98},
  abstract = {The 3D tree visualization faces multiples challenges: the election
	of an appropriate layout, the use of the interactions that make it
	easier the data exploration and a metaphor that helps the information
	understanding. A good combination of these three elements (layout,
	interactions and metaphor) will result in a visualization that effectively
	convey the key features of a complex structure or system to a wide
	range of users and permits the analytical reasoning process. The
	goal of this work was centered in the 3D tree visualization. In spite
	of their apparent simplicity, the displaying of a tree in 3D can
	also introduce new problems that can be overcome with the appropriate
	interactions. So, we have developed a new visualization technique
	for 3D tree visualization; this includes the design of a new tree
	layout that we called Spherical layout and the set of interactions
	that can be applied on this representation. This technique allows
	representing hierarchical structures to different levels of detail
	and also can be used as a visualization technique that allows a tree
	with attribute to be visualized. The Spherical layout has shown good
	result for large trees without compromising the performance; this
	is a key issue in tree visualization.},
  crossref = {IHCI2007},
  url = {http://www.iadis.net/dl/final_uploads/200710L012.pdf}
}

@INPROCEEDINGS{Liggesmeyer2009,
  author = {Peter Liggesmeyer and Jens Heidrich and J\"urgen M\"unch and Robert
	Kalckl\"osch and Henning Barthel and Dirk Zeckzer},
  title = {Visualization of Software and Systems as Support Mechanism for Integrated
	Software Project Control},
  pages = {846--855},
  abstract = {Many software development organizations still lack support for obtaining
	intellectual control over their software development processes and
	for determining the performance of their processes and the quality
	of the produced products. Systematic support for detecting and reacting
	to critical process and product states in order to achieve planned
	goals is usually missing. One means to institutionalize measurement
	on the basis of explicit models is the development and establishment
	of a so-called Software Project Control Center (SPCC) for systematic
	quality assurance and management support. An SPCC is comparable to
	a control room, which is a well known term in the mechanical production
	domain. One crucial task of an SPCC is the systematic visualization
	of measurement data in order to provide context-, purpose-, and role-oriented
	information for all stakeholders (e.g., project managers, quality
	assurance managers, developers) during the execution of a software
	development project. The article will present an overview of SPCC
	concepts, a concrete instantiation that supports goal-oriented data
	visualization, as well as examples and experiences from practical
	applications.},
  crossref = {HCII2009},
  doi = {10.1007/978-3-642-02574-7_94}
}

@INPROCEEDINGS{Lin2005,
  author = {Chun-Cheng Lin and Hsu-Chun Yen},
  title = {On Balloon Drawings of Rooted Trees},
  pages = {285--296},
  abstract = {Among various styles of tree drawing, balloon drawing, where each
	subtree is enclosed in a circle, enjoys a desirable feature of displaying
	tree structures in a rather balanced fashion. We first design an
	efficient algorithm to optimize angular resolution and aspect ratio
	for the balloon drawing of rooted unordered trees. For the case of
	ordered trees for which the center of the enclosing circle of a subtree
	need not coincide with the root of the subtree, flipping the drawing
	of a subtree (along the axis from the parent to the root of the subtree)
	might change both the aspect ratio and the angular resolution of
	the drawing. We show that optimizing the angular resolution as well
	as the aspect ratio with respect to this type of rooted ordered trees
	is reducible to the perfect matching problem for bipartite graphs,
	which is solvable in polynomial time. Aside from studying balloon
	drawing from an algorithmic viewpoint, we also propose a local magnetic
	spring model for producing dynamic balloon drawings with applications
	to the drawings of galaxy systems, H-trees, and sparse graphs, which
	are of practical interest.},
  crossref = {GD2005},
  doi = {10.1007/11618058_26}
}

@INPROCEEDINGS{Lin2007a,
  author = {Chun-Cheng Lin and Hsu-Chun Yen},
  title = {Balloon Views of Source Code and Their Multiscalable Font Modes},
  pages = {53--58},
  abstract = {The majority of program editors available on the market support the
	view of a directory-explorer style to display only those code lines
	of interest. Among them, the fisheye and the fractal views of source
	code (in which each line has a value reflecting the degree of interest
	and importance) have received a lot of attention in the literature.
	In information visualization, drawing trees based on fractal theory
	also plays an interesting role as the so-called balloon drawing of
	hierarchical data includes two models: the fractal and the SNS (subtrees
	with nonuniform sizes) models. It is therefore natural to consider
	a new source code visualization style based on the SNS model of balloon
	drawing. A main feature of the SNS view is that the value of each
	line reflects the number of its descendants when the source code
	is viewed as a tree structure. Unlike the view of a directory-explorer
	style, the multiscalable font mode (which was originally utilized
	in the fractal view of source code) displays all the lines in such
	a way that each line has the font size proportional to its value.
	In this paper, we investigate various issues concerning the multiscalable
	font modes of the fish-eye, the fractal, and the SNS views of source
	code, in hope of providing guidelines for the programmer to better
	comprehend the program code in practice.},
  crossref = {IV2007},
  doi = {10.1109/IV.2007.30}
}

@INPROCEEDINGS{Liu2008,
  author = {Shixia Liu and Nan Cao and Hao Lv},
  title = {Interactive Visual Analysis of the {NSF} Funding Information},
  pages = {183--190},
  abstract = {This paper presents an interactive visualization toolkit for navigating
	and analyzing the National Science Foundation (NSF) funding information.
	Our design builds upon the treemap layout and the stacked graph to
	contribute customized techniques for visually navigating and interacting
	with the hierarchical data of NSF programs and proposals, supporting
	visual search and analysis, and allowing the user to make informed
	decision. In this visualization toolkit, we propose two visualization
	techniques to simplify the navigation of the hierarchical data: 2.5
	Dimensional treemaps to make the hierarchical structure more easily
	to be recognized, and labeled treemap to help the user to get a clear
	overview of the content of the structure and make the internal area
	of rectangles correspond to the weights of the data set. Furthermore,
	an incremental layout method is adopted to handle information on
	a large scale. The improved treemap visualization will help to visually
	analyze the static funding data and the stacked graph is utilized
	to analyze the time-series data. Through these visual analysis techniques,
	research trends of NSF, popular NSF programs are quickly identified.
	The primary contribution is a demonstration of novel ways to effectively
	present and analyze NSF funding data.},
  crossref = {PACIFICVIS2008},
  doi = {10.1109/PACIFICVIS.2008.4475475}
}

@INPROCEEDINGS{Liu2006,
  author = {Shixia Liu and Nan Cao and Hao Lv and Hui Su},
  title = {The visual funding navigator: Analysis of the {NSF} funding information},
  pages = {882--883},
  abstract = {This paper presents an interactive visualization toolkit for navigating
	and analyzing the National Science Foundation (NSF) funding information.
	Our design builds upon an improved 2.5D treemap layout and the stacked
	graph to contribute customized techniques for visually navigating
	and interacting with the hierarchical data of NSF programs and proposals.
	Furthermore, an incremental layout method is adopted to handle information
	on a large scale. The improved treemap visualization will help to
	visually analyze the static funding related data and the stacked
	graph is utilized to analyze the time-series data. Through these
	visual analysis techniques, research trends of NSF, popular NSF programs
	are quickly identified.},
  crossref = {CIKM2006},
  doi = {10.1145/1183614.1183778}
}

@INPROCEEDINGS{Lou2008,
  author = {Xinghua Lou and Shixia Liu and Tianshu Wang},
  title = {{FanLens}: A Visual Toolkit for Dynamically Exploring the Distribution
	of Hierarchical Attributes},
  pages = {151--158},
  abstract = {Radial, space-filling visualization is very useful for representing
	the distribution of attributes in hierarchical data; however it also
	suffers from its drawbacks in terms of view transition, context preservation,
	thin slices, flexibility and large sized data support. To address
	these problems, we propose FanLens, an enhancement upon existing
	approaches with new features like incremental layout and fisheye
	distortion based selecting. This visual toolkit also features dynamic
	hierarchy specification, dynamic visual property mapping, smooth
	animation, etc. We illustrate the effectiveness of our technique
	with two examples of case study and results from informal user experiments.},
  crossref = {PACIFICVIS2008},
  doi = {10.1109/PACIFICVIS.2008.4475471}
}

@INPROCEEDINGS{Luboschik2007,
  author = {Martin Luboschik and Heidrun Schumann},
  title = {Explode to Explain -- Illustrative Information Visualization},
  pages = {301--307},
  abstract = {Due to complexity, modern visualization techniques for large data
	volumes and complex interrelationships are difficult to understand
	for non-expert users and even for expert users the visualization
	result may be difficult to interpret. Often the limited screen space
	and the risk of occlusion hinders a meaningful explanation of techniques
	or datasets by additional visual elements. This paper presents a
	novel way how views from information visualization can be adapted
	by the use of the well-known illustrative technique "exploded view",
	to successfully face the problems described above. The application
	of exploded views gains screen space for an explanation in a smart
	way and acts explanatory itself. With our approach of illustrating
	visual representations, the understanding of complex visualization
	techniques is eased and new comprehensible views on data are given.},
  crossref = {IV2007},
  doi = {10.1109/IV.2007.50}
}

@INPROCEEDINGS{Metaxas1994,
  author = {Panagiotis T. Metaxas and Grammati E. Pantziou and Antonis Symvonis},
  title = {Parallel h-v drawings of binary trees},
  pages = {487--495},
  abstract = {In this paper we present a method to obtain optimal h-v and inclusion
	drawings in parallel. Based on parallel tree contraction, our method
	computes optimal (with respect to a class of cost functions of the
	enclosing rectangle) drawings in O(log2n) parallel time by using
	a polynomial number of EREW processors. The method can be extended
	to compute optimal inclusion layouts in the case where each leaf
	l of the tree is represented by rectangle l x*l y. Our method also
	yields an NC algorithm for the slicing floorplanning problem. Whether
	this problem was in NC was an open question.},
  crossref = {ISAAC1994},
  doi = {10.1007/3-540-58325-4_215}
}

@INPROCEEDINGS{Miller2011,
  author = {Robert Miller and Vadim Mozhayskiy and Ilias Tagkopoulos and Kwan-Liu
	Ma},
  title = {{EVEVis}: A Multi-Scale Visualization System for Dense Evolutionary
	Data},
  year = {2011},
  pages = {143--150},
  abstract = {Evolutionary simulations can produce datasets consisting of thousands
	or millions of separate entities, complete with their genealogical
	relationships. Biologists must examine this data to determine when
	and where these entities have changed, both on an individual basis
	and on a population-wide basis. Therefore, desirable features of
	a visualization system for evolutionary data are the capability of
	showing the status of the population at any given moment in time,
	good scalability, and smooth transition between high-level and low-level
	views. We propose a multi-scale visualization method, including a
	novel tree layout that both shows population status over time and
	can easily scale to very large populations. From this layout, the
	user can navigate to visualizations for moments in time or for individual
	entities. We demonstrate the effectiveness of the visualization on
	an existing evolutionary simulation called EVE: Evolution in Variable
	Environments.},
  crossref = {BioVis2011},
  doi = {10.1109/BioVis.2011.6094059}
}

@INPROCEEDINGS{Miyazaki2009,
  author = {Reiko Miyazaki and Takayuki Itoh},
  title = {An Occlusion-Reduced 3D Hierarchical Data Visualization Technique},
  pages = {38--43},
  abstract = {Occlusion is an important problem to be solved for readability improvement
	of 3D visualization techniques. This paper presents an occlusion
	reduction technique for cityscape-style 3D visualization techniques.
	The paper first presents an algorithm for occlusion reduction. It
	generates bounding boxes of 3D objects on the 2D display space, moves
	them to reduce their overlap, and finally reversely projects their
	movements onto the 3D space. The paper then presents an application
	of the algorithm to our own hierarchical data visualization technique,
	and a music browser based on the technique. The paper also shows
	several numerical evaluations that denote the effectiveness of the
	presented technique.},
  crossref = {IV2009},
  doi = {10.1109/IV.2009.32}
}

@INPROCEEDINGS{Mizukoshi2006,
  author = {Daisuke Mizukoshi and Yukio Hori and Tomonori Gotoh},
  title = {Extension models of {Cone Tree} Visualizations to Large scale Knowledge
	base with Semantic Relations},
  pages = {19--20},
  abstract = {Cone Tree is an appealing interactive 3D visualization model for hierarchical
	data structure. In any prior studies, data objects for visualization
	were constructed by only tree structure, which contained small number
	of data and nodes. Subject domains in real world for visualization
	studies have highly complicated relations, which cannot to be expressed
	in a few nodes and only hierarchical structure. In this paper, we
	proposed the visualization technique based on cone tree model to
	apply for a large-scale knowledge base, which has complicated data
	structure. The EDR Electronic Dictionary as a large-scale knowledge
	base was used in our study. The visualization system fro EDR was
	implemented with Java 3D. This paper describes the technique and
	the implemented system, and discusses some problems on the technique.},
  crossref = {WSCGposter2006},
  url = {http://wscg.zcu.cz/wscg2006/Papers_2006/Poster/C89-full.pdf}
}

@INPROCEEDINGS{MohammadiAragh2005,
  author = {Mahnas Jean Mohammadi-Aragh and T. J. Jankun-Kelly},
  title = {MoireTrees: Visualization and Interaction for Multi-Hierarchical
	Data},
  pages = {231--238},
  abstract = {Visualizing hierarchical data is one of the core areas of information
	visualization. Most of these techniques focus on single hierarchies
	- hierarchies with a single root element and a single path to each
	element. In contrast, this work focuses on the browsing of multi-hierarchies
	- hierarchies with multiple roots or multiple paths per element.
	A radial focus+context display algorithm and interaction methods
	are introduced to explore such multi-hierarchical data. A series
	of examples demonstrate the effectiveness of our new visualization.},
  crossref = {EUROVIS2005},
  doi = {10.2312/VisSym/EuroVis05/231-238}
}

@INPROCEEDINGS{Mondal2011,
  author = {Debajyoti Mondal and Muhammad Jawaherul Alam and Md. Saidur Rahman},
  title = {Minimum-Layer Drawings of Trees},
  pages = {221--232},
  abstract = {A layered drawing of a tree T is a planar straight-line drawing of
	T, where the vertices of T are placed on some horizontal lines called
	layers. A minimum-layer drawing of T is a layered drawing of T on
	k layers, where k is the minimum number of layers required for any
	layered drawing of T. In this paper we give a linear-time algorithm
	for obtaining minimum-layer drawings of trees.},
  crossref = {WALCOM2011},
  doi = {10.1007/978-3-642-19094-0_23}
}

@INPROCEEDINGS{Moret2009,
  author = {Philippe Moret and Walter Binder and Danilo Ansaloni and Alex Villaz\'on},
  title = {Visualizing Calling Context profiles with Ring Charts},
  pages = {33-36},
  abstract = {Calling context profiling is an important technique for analysing
	the performance of object-oriented software with complex inter-procedural
	control flow. A common data structure is the Calling Context Tree
	(CCT), which stores dynamic metrics, such as CPU time, separately
	for each calling context. As CCTs may comprise millions of nodes,
	there is need for a condensed visualization that eases the location
	of performance bottlenecks. In this paper, we introduce Calling Context
	Ring Charts, a new compact visualization for CCTs, where callee methods
	are represented in ring segments surrounding the caller's ring segment.
	In order to reveal hot methods, their callers, and callees, the ring
	segments can be sized according to a chosen dynamic metric.},
  crossref = {VISSOFT2009},
  doi = {10.1109/VISSOF.2009.5336425}
}

@INPROCEEDINGS{Munzner1997,
  author = {Tamara Munzner},
  title = {H3: laying out large directed graphs in {3D} hyperbolic space},
  pages = {2--10},
  abstract = {We present the H3 layout technique for drawing large directed graphs
	as node-link diagrams in 3D hyperbolic space. We can lay out much
	larger structures than can be handled using traditional techniques
	for drawing general graphs because we assume a hierarchical nature
	of the data. We impose a hierarchy on the graph by using domain-specific
	knowledge to find an appropriate spanning tree. Links which are not
	part of the spanning tree do not influence the layout but can be
	selectively drawn by user request. The volume of hyperbolic 3-space
	increases exponentially, as opposed to the familiar geometric increase
	of euclidean 3-space. We exploit this exponential amount of room
	by computing the layout according to the hyperbolic metric. We optimize
	the cone tree layout algorithm for 3D hyperbolic space by placing
	children on a hemisphere around the cone mouth instead of on its
	perimeter. Hyperbolic navigation affords a Focus+Context view of
	the structure with minimal visual clutter. We have successfully laid
	out hierarchies of over 20,000 nodes. Our implementation accommodates
	navigation through graphs too large to be rendered interactively
	by allowing the user to explicitly prune or expand subtrees.},
  crossref = {INFOVIS1997},
  doi = {10.1109/INFVIS.1997.636718}
}

@INPROCEEDINGS{Munzner1998a,
  author = {Tamara Munzner},
  title = {Drawing Large Graphs with {H3Viewer} and {Site Manager}},
  pages = {384--393},
  abstract = {We demonstrate the H3Viewer graph drawing library, which can be run
	from a standalone program or in conjunction with other programs such
	as SGI's Site Manager application. Our layout and drawing algorithms
	support interactive navigation of large graphs up to 100,000 edges.
	We present an adaptive drawing algorithm with a guaranteed frame
	rate. Both layout and navigation occur in 3D hyperbolic space, which
	provides a view of a large neighborhood around an easily changeable
	point of interest. We find an appropriate spanning tree to use as
	the backbone for fast layout and uncluttered drawing, and non-tree
	links can be displayed on demand. Our methods are appropriate when
	node or link annotations can guide the choice of a good parent from
	among all of the incoming links. Such annotations can be constructed
	using only a small amount of domain-specific knowledge, thus rendering
	tractable many graphs which may seem rather densely connected at
	first glance.},
  crossref = {GD1998},
  doi = {10.1007/3-540-37623-2_30}
}

@INPROCEEDINGS{Neumann2006,
  author = {Petra Neumann and Sheelagh Carpendale and Anand Agarawala},
  title = {{PhylloTrees}: Phyllotactic Patterns for Tree Layout},
  pages = {59--66},
  abstract = {Motivations for drawing hierarchical structures are probably as diverse
	as datasets to visualize. This ubiquity of tree structures has lead
	to a manifold of tree layout algorithms and tree visualization systems.
	While many tree layouts exist, increasingly massive data sets, expanding
	computational power, and still relatively limited display space make
	tree layout algorithms a topic of ongoing interest. We explore the
	use of nature's phyllotactic patterns to inform the layout of hierarchical
	data. These naturally occurring patterns provide a non-overlapping,
	optimal packing when the total number of nodes is not known a priori.
	We present PhylloTrees, a family of expandable tree layouts based
	on these patterns.},
  crossref = {EUROVIS2006},
  doi = {10.2312/VisSym/EuroVis06/059-066}
}

@INPROCEEDINGS{Nguyen2002,
  author = {Quang Vinh Nguyen and Mao Lin Huang},
  title = {A Space-Optimized Tree Visualization},
  pages = {85--92},
  abstract = {We describe a new method for the visualization of tree structured
	relational data. It can be used especially for the display of very
	large hierarchies in a 2-dimensional space. We discuss the advantages
	and limitations of current techniques of tree visualization. Our
	strategy is to optimize the drawing of trees in a geometrical plane
	and maximize the utilization of display space by allowing more nodes
	and links to be displayed at a limit screen resolution. We use the
	concept of enclosure to partition the entire display space into a
	collection of local regions that are assigned to all nodes in tree
	T for the display of their sub-trees and themselves. To enable the
	exploration of large hierarchies, we use a modified semantic zooming
	technique to view the detail of a particular part of the hierarchy
	at a time based on user's interest. Layout animation is also provided
	to preserve the mental map while the user is exploring the hierarchy
	by changing zoomed views.},
  crossref = {INFOVIS2002},
  doi = {10.1109/INFVIS.2002.1173152}
}

@INPROCEEDINGS{Nguyen2004a,
  author = {Quang V. Nguyen and Mao L. Huang},
  title = {Visualising file-systems using {ENCCON} model},
  pages = {61--65},
  abstract = {This paper describes a new approach for visualising the file structures.
	Our technique uses an <u>enc</u>losure + <u>con</u>nection (ENCCON)
	approach that provides an overall view of the entire file/directory
	hierarchy that gives a better understanding of the folder-folder
	and folder-file relationships, and therefore makes easier for the
	navigation. We firstly use the rectangular regions to present the
	folders. This allows the user to immediately percept the location,
	size (number of files contained) and other properties of any particular
	folder. To enrich the visual attributes of the file structure, we
	also use a node-link diagram to present the "belonging" relationships.
	This "belonging" relationship includes folder-folder and folder-file
	relationships. We use a semantic zooming technique to enlarge the
	display of files and folders in a particular focused area. The animation
	is also accommodated in order to preserve the mental map [Bartram
	1997] during the navigation.},
  crossref = {VIP2004},
  url = {http://portal.acm.org/citation.cfm?id=1082121.1082131}
}

@INPROCEEDINGS{Nguyen2004,
  author = {Quang Vinh Nguyen and Mao Lin Huang},
  title = {Hierarchical Information Visualization using ENCCON Model},
  year = {2004},
  abstract = {This paper describes a new efficient approach for visualizing large
	hierarchical information. Our technique is based on the connection
	+ enclosure visualization model from which the area division is used
	for the recursive positioning of nodes, while a node-link diagram
	is still drawn to present the entire hierarchical structure. We inherit
	the advantages of Space-Optimized (SO) Tree technique that can enhance
	the usability of display space by using area division. However, we
	replace a set of polygons used in SO Tree by a set of rectangles
	for the area division. This not only decreases the computation cost
	in calculating geometrical polygons, but also greatly reduces the
	human perceptual and cognitive loads spent on understanding the underlying
	hierarchical structure. We use semantic zooming technique to enlarge
	a particular viewing area and filter out the rest of structure that
	is less interested. The navigation is accommodated by animation in
	order to preserve the mental map.},
  crossref = {SE2004},
  url = {http://www.actapress.com/PaperInfo.aspx?PaperID=16436}
}

@INPROCEEDINGS{Nguyen2000,
  author = {Trong Dung Nguyen and Tu Bao Ho and Hiroshi Shimodaira},
  title = {A visualization tool for interactive learning of large decision trees},
  pages = {28--35},
  abstract = {Decision tree induction is certainly among the most applicable learning
	techniques due to its power and simplicity. However learning decision
	trees from large datasets, particularly in data mining, is quite
	different from learning from small or moderately sized datasets.
	When learning from large datasets, decision tree induction programs
	often produce very large trees. How to efficiently visualize trees
	in the learning process, particularly large trees, is still questionable
	and currently requires efficient tools. The paper presents a visualization
	tool for interactive learning of large decision trees, that includes
	a new visualization technique called T2.5D (Trees 2.5 Dimensions).
	After a brief discussion on requirements for tree visualizers and
	related work, the paper focuses on presenting developing techniques
	for two issues: (1) how to visualize efficiently large decision trees;
	and (2) how to visualize decision trees in the learning process},
  crossref = {ICTAI2000},
  doi = {10.1109/TAI.2000.889842}
}

@INPROCEEDINGS{ODonnell2006,
  author = {Richard O'Donnell and Alan Dix and Linden J. Ball},
  title = {Exploring the {PieTree} for Representing Numerical Hierarchical Data},
  pages = {239--254},
  abstract = {This paper describes the first full implementation and evaluation
	of an area-based tree visualization known as the PieTree. The PieTree
	was first proposed in papers in 1998 and 2000 but has never been
	fully implemented and evaluated. Informal evaluation was used to
	enhance the usability of the PieTree and compare it with the more
	well-known TreeMap. A controlled experiment considered parallel views'
	effect on task performance time. There were substantial differences
	between kinds of tasks and in participants' styles of use. Whilst
	suggesting that further development of PieTrees is worthwhile the
	experiments underline the importance of careful task fit.},
  crossref = {HCI2006},
  doi = {10.1007/978-1-84628-664-3_18}
}

@INPROCEEDINGS{Onak2008,
  author = {Krzysztof Onak and Anastasios Sidiropoulos},
  title = {Circular Partitions with Applications to Visualization and Embeddings},
  pages = {28--37},
  abstract = {We introduce a hierarchical partitioning scheme of the Euclidean plane,
	called circular partitions. Such a partition consists of a hierarchy
	of convex polygons, each having small aspect ratio, and satisfying
	specified volume constraints. We apply these partitions to obtain
	a natural extension of the popular Treemap visualization method.
	Our proposed algorithm is not constrained in using only rectangles,
	and can achieve provably better guarantees on the aspect ratio of
	the constructed polygons.
	
	Under relaxed conditions, we can also construct circular partitions
	in higher-dimensional spaces. We use these relaxed partitions to
	obtain improved approximation algorithms for embedding ultrametrics
	into d-dimensional Euclidean space. In particular, we give a polylog(Delta)-approximation
	algorithm for embedding n-point ultrametrics into R^d with minimum
	distortion (Delta denotes the spread of the metric). The previously
	best-known approximation ratio for this problem was polynomial in
	n. This is the first algorithm for embedding a non-trivial family
	of weighted graph metrics into a space of constant dimension that
	achieves polylogarithmic approximation ratio.},
  crossref = {SCG2008},
  doi = {10.1145/1377676.1377683}
}

@INPROCEEDINGS{Ong2005,
  author = {TeongJoo Ong and John J. Leggett and Unil Yun},
  title = {Visualizing Hierarchies and Collection Structures with Fractal Trees},
  pages = {31--40},
  abstract = {This paper addresses the need for better information access to digital
	library collections. Without proper visualization tools, organizational
	and structural information is often lost or suppressed by digital
	library interfaces. We discuss a 2D fractal tree visualization tool
	that can be used to more accurately present the structure, organization
	and interrelation of collection metadata.},
  crossref = {ENC2005},
  doi = {10.1109/ENC.2005.53}
}

@INPROCEEDINGS{Otjacques2009,
  author = {Beno\^{\i}t Otjacques and Ma\"{e}l Cornil and Monique Noirhomme and
	Fernand Feltz},
  title = {{CGD} -- A New Algorithm to Optimize Space Occupation in Ellimaps},
  pages = {805--818},
  abstract = {How to visualize datasets hierarchically structured is a basic issue
	in information visualization. Compared to the common diagrams based
	on the nodes-links paradigm (e.g. trees), the enclosure-based methods
	have shown high potential to represent simultaneously the structure
	of the hierarchy and the weight of nodes. In addition, these methods
	often support scalability up to sizes where trees become very complicated
	to understand. Several approaches belong to this class of visualization
	methods such as treemaps, ellimaps, circular treemaps or Voronoi
	treemaps. This paper focuses on the specific case of ellimaps in
	which the nodes are represented by ellipses nested one into each
	other. A controlled experiment has previously shown that the initial
	version of the ellimaps was efficient to support the perception of
	the dataset structure and was reasonably acceptable for the perception
	of the node weights. However it suffers from a major drawback in
	terms of display space occupation. We have tackled this issue and
	the paper proposes a new algorithm to draw ellimaps. It is based
	on successive distortions and relocations of the ellipses in order
	to occupy a larger proportion of the display space than the initial
	algorithm. A Monte-Carlo simulation has been used to evaluate the
	filling ratio of the display space in this new approach. The results
	show a significant improvement of this factor.},
  crossref = {INTERACT2009},
  doi = {10.1007/978-3-642-03658-3_84}
}

@INPROCEEDINGS{Otjacques2007a,
  author = {Beno\^{\i}t Otjacques and Monique Noirhomme and Fernand Feltz},
  title = {Innovative Visualization Tools to Monitor Scientific Cooperative
	Activities},
  pages = {33--41},
  abstract = {This paper describes how information visualization techniques can
	be used to monitor a web-based collaborative platform and to support
	workplace awareness by providing a global overview of the activities.
	An innovative prototype is described. Its originality relies on using
	some enclosure-based visualization methods in the context of activities
	monitoring, which is rather unusual. In addition, a new layout is
	described for representing data trees. The use of the system is illustrated
	with the case of a EU-funded Network of Excellence.},
  crossref = {CDVE2007},
  doi = {10.1007/978-3-540-74780-2_4}
}

@INPROCEEDINGS{Otjacques2007,
  author = {Beno\^{\i}t Otjacques and Monique Noirhomme and Xavier Gobert and
	Pierre Collin and Fernand Feltz},
  title = {Visualizing the activity of a web-based collaborative platform},
  pages = {251--256},
  abstract = {This paper describes a prototype that offers visualization features
	for monitoring a Web-based collaborative platform. The data displayed
	supports workplace awareness by providing an overview of the activities
	carried out on the platform. The prototype focuses on the information
	structured as hierarchical data. Three views are included: a classic
	vertical tree, a treemap view and an original new layout called ellimap.
	The system has been implemented on a real case in the domain of the
	support to innovation.},
  crossref = {IV2007},
  doi = {10.1109/IV.2007.137}
}

@INPROCEEDINGS{Parks2009,
  author = {Donovan H. Parks and Robert G. Beiko},
  title = {Quantitative visualizations of hierarchically organized data in a
	geographic context},
  abstract = {Here we introduce a novel quantitative technique for visualizing hierarchically
	organized data in a geographic context. In contrast to existing techniques,
	our visualization emphasizes the hierarchical relationships in the
	data by depicting them in a standard tree format that takes advantage
	of many fundamental perceptual properties. Our technique allows users
	to define a geographic axis and visualize how well a tree correlates
	with the ordering of geographical locations along this axis. This
	is accomplished by finding the ordering of leaf nodes, subject to
	the constraints of the tree topology, which minimizes the number
	of crossings that occur between lines that connect leaf nodes to
	their associated geographic locations. In this optimal layout, any
	crossings that occur between these lines indicate discordance between
	the topology of the tree and the user defined geographic axis. We
	have developed a branch-and-bound algorithm that allows optimal leaf
	orderings to be determined quickly enough to support interactive
	exploration of different geographic axes even for large multifurcating
	hierarchies. The quantitative nature of our visualization has allowed
	us to specify a permutation test for determining if the relationship
	between a tree topology and a geographic axis is statistically significant.
	In this paper, the utility of our visualization is demonstrated on
	biological data sets, but our method is applicable to any hierarchical
	data where geographic structure may be of interest.},
  crossref = {GeoInformatics2009},
  doi = {10.1109/GEOINFORMATICS.2009.5293552}
}

@INPROCEEDINGS{Parsia2005,
  author = {Bijan Parsia and Taowei Wang and Jennifer Golbeck},
  title = {Visualizing Web Ontologies with {CropCircles}},
  abstract = {We apply a new visualization for complex heirarchies, CropCircles,
	to the interactive visualization ofWeb Ontologies and E-Connections
	of Web Ontologies.},
  crossref = {EUSW2005},
  url = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-172/enduserSWI_paper05.pdf}
}

@INPROCEEDINGS{Plaisant2002,
  author = {Catherine Plaisant and Jesse Grosjean and Benjamin B. Bederson},
  title = {{SpaceTree}: Supporting Exploration in Large Node Link Tree, Design
	Evolution and Empirical Evaluation},
  pages = {57--64},
  abstract = {We present a novel tree browser that builds on the conventional node
	link tree diagrams. It adds dynamic rescaling of branches of the
	tree to best fit the available screen space, optimized camera movement,
	and the use of preview icons summarizing the topology of the branches
	that cannot be expanded. In addition, it includes integrated search
	and filter functions. This paper reflects on the evolution of the
	design and highlights the principles that emerged from it. A controlled
	experiment showed benefits for navigation to already previously visited
	nodes and estimation of overall tree topology.},
  crossref = {INFOVIS2002},
  doi = {10.1109/INFVIS.2002.1173148}
}

@INPROCEEDINGS{Pulo2003a,
  author = {Kevin Pulo and Peter Eades and Masahiro Takatsuka},
  title = {Smooth Structural Zooming of h-v Inclusion Tree Layouts},
  pages = {14--25},
  abstract = {We present a new paradigm for achieving focus+context visualizations
	called smooth structural zooming, which varies the level of detail
	of the data in different areas of the visualization, as opposed to
	geometrically distorting the visualization or employing rapid zooming
	techniques. A smooth structural zooming technique for horizontal-vertical
	(h-v) inclusion tree layouts is described and applied to the domain
	of the software design process, specifically, design behaviour trees
	(DBTs). This system has the ability to navigate and explore data
	too large to be fully displayed, whilst maintaining an approximately
	constant level of visual complexity, good visualization aesthetics
	and preservation of the user's mental map through animation. The
	technique may be readily extended to arbitrary layout styles and
	algorithms, and to other hierarchical data structures and relational
	information, such as clustered graphs.},
  crossref = {CMV2003},
  doi = {10.1109/CMV.2003.1214999}
}

@INPROCEEDINGS{Pulo2003,
  author = {Kevin Pulo and Masahiro Takatsuko},
  title = {Inclusion Tree Layout Convention: An Empirical Investigation},
  pages = {27--37},
  abstract = {The inclusion tree layout convention involves drawing trees as nested
	rectangles rather than the more common node-link diagrams. Finding
	good inclusion layouts presents some unique challenges, for example,
	the quantification of what is meant by the "size" of a rectangle.
	This paper empirically evaluates and investigates several rectangle
	size measures for their usefulness in the inclusion tree layout convention.
	We find that the area size measure, commonly used in graph drawing,
	is very poorly suited to the inclusion layout convention, whilst
	size measures based on the aspect ratio of the layout are more appropriate
	and give better results.},
  crossref = {APVIS2003},
  url = {http://portal.acm.org/citation.cfm?id=857084}
}

@INPROCEEDINGS{Rekimoto1993,
  author = {Jun Rekimoto and Mark Green},
  title = {The information cube: Using transparency in {3D} information visualization},
  pages = {125--132},
  abstract = {In this paper, we propose a new 3D visualization technique for hierarchical
	information. This technique is based on the nested box metaphor,
	a familiar concept for any users. By using semi-transparent rendering,
	the system controls the complexity of the information presented to
	the user. With several 3D interaction techniques provided by the
	system, the user can recognize and inspect the information structure
	intuitively. Normally, the user puts on the VR equipment to use the
	system, but the system is also accessible through a conventional
	CRT display.},
  crossref = {WITS1993}
}

@INPROCEEDINGS{Robertson1991,
  author = {George G. Robertson and Jock D. Mackinlay and Stuart K. Card},
  title = {{Cone Trees}: Animated 3D visualizations of hierarchical information},
  pages = {189--194},
  abstract = {The task of managing and accessing large information spaces is a problem
	in large scale cognition. Emerging technologies for 3D visualization
	and interactive animation offer potential solutions to this problem,
	especially when the structure of the information can be visualized.
	We describe one of these Information Visualization techniques, called
	the Cone Tree, which is used for visualizing hierarchical information
	structures. The hierarchy is presented in 3D to maximize effective
	use of available screen space and enable visualization of the whole
	structure. Interactive animation is used to shift some of the user's
	cognitive load to the human perceptual system.},
  crossref = {CHI1991},
  doi = {10.1145/108844.108883}
}

@INPROCEEDINGS{Rusu2007,
  author = {Adrian Rusu and Confesor Santiago and Radu Jianu},
  title = {Real-time interactive visualization of information hierarchies},
  pages = {117--123},
  abstract = {An information hierarchy is a collection of relational information
	that is arranged in a ranking organization where each entity is subject
	to a single other entity, except for the top (root) element. The
	usefulness of a visualization of an information hierarchy depends
	on its capability of conveying the information quickly and clearly.
	The interaction with the information hierarchy allows a user to further
	analyze its underlying structures and relationships, which is essential
	for the effectiveness of the visualization. In this paper we present
	a novel method to interactively visualize information hierarchies
	in real-time. We use the World Wide Web as an application example
	of our techniques. The result is a novel Web browsing and visualization
	method with an innovative combination of features: (i) Web data is
	retrieved and displayed in real-time (i.e. Web data is not pre-recorded),
	(ii) browsing and visualization are synchronized together in the
	same interface, (iii) tree-based visualization engine, and (iv) space-efficient
	display of visualization. Our study shows that users are able to
	orient themselves better in cyberspace and locate Web pages of interest
	faster.},
  crossref = {IV2007},
  doi = {10.1109/IV.2007.92}
}

@INPROCEEDINGS{Schedl2007,
  author = {Markus Schedl and Peter Knees and Gerhard Widmer and Klaus Seyerlehner
	and Tim Pohle},
  title = {Browsing the Web Using Stacked Three-Dimensional Sunbursts to Visualize
	Term Co-Occurrences and Multimedia Content},
  pages = {2--3},
  abstract = {We present a novel visualization approach that extends the Sunburst
	technique to the third dimension, which allows for encoding additional
	data in the height of each arc segment. By stacking a number of such
	3D-Sunbursts, we build a user interface for browsing collections
	of web pages. We apply techniques for web content indexing of multimedia
	data (text, audio, image, video) and text analysis to create a UI
	where each layer of the Sunburst stack represents a specific multimedia
	content type. We call this user interface the Co-Occurrence Browser
	(COB) and demonstrate its usability on a collection of web pages
	related to music artists.},
  crossref = {INFOVISposter2007},
  url = {http://www.cp.jku.at/research/papers/Schedl_etal_Vis_2007.pdf}
}

@INPROCEEDINGS{Schreck2006,
  author = {Tobias Schreck and Daniel Keim and Florian Mansmann},
  title = {Regular TreeMap Layouts for Visual Analysis of Hierarchical Data},
  pages = {184--191},
  abstract = {Hierarchical relationships play an utmost important role in many application
	domains. The appropriate visualization of hierarchically structured
	data sets can contribute towards supporting the data analyst in effectively
	analyzing hierarchic structures using visualization as a user friendly
	means to communicate information. Information Visualization has contributed
	a number of useful techniques for visualization of hierarchically
	structured data sets. Yet, the support for certain regularity requirements
	as arising from many data element types has to be improved. In this
	paper, we analyze an existing variant of the popular TreeMap family
	of hierarchical layout algorithms, and we introduce a novel TreeMap
	algorithm supporting space efficient layout of hierarchical data
	sets providing global regular layouts. We detail our algorithm, and
	we present applications on a real-world data set as well as experiments
	performed on a synthetic data set, showing its applicability and
	usefulness.},
  crossref = {SCCG2006},
  url = {http://www.inf.uni-konstanz.de/gk/pubsys/publishedFiles/ScKeMa06.pdf}
}

@INPROCEEDINGS{Schulz2008,
  author = {Hans-J\"org Schulz and Steffen Hadlak and Heidrun Schumann},
  title = {A Point-Based Layout for Large Hierarchies},
  abstract = {Space-filling layout techniques for tree representations are frequently
	used when the available screen space is small or the data set is
	large. In this paper, we propose a new approach to space-filling
	tree representations, which uses mechanisms from the point-based
	rendering paradigm. We also numerically evaluate our new technique
	together with two established space-filling techniques using the
	measures of the Ink-Paper-Ratio and overplotted\%.},
  crossref = {INFOVISposter2008},
}

@INPROCEEDINGS{Schulz2009,
  author = {Hans-J\"org Schulz and Steffen Hadlak and Heidrun Schumann},
  title = {Point-based tree representation: A new approach for large hierarchies},
  pages = {81--88},
  abstract = {Space-filling layout techniques for tree representations are frequently
	used when the available screen space is small or the data set is
	large. In this paper, we propose a new approach to space-filling
	tree representations, which uses mechanisms from the point-based
	rendering paradigm. Additionally, helpful interaction techniques
	that tie in with our layout are presented. We will relate our new
	technique to established space-filling techniques along the lines
	of a newly developed classification and also evaluate it numerically
	using the measures of the Ink-Paper-Ratio and overplotted\%.},
  crossref = {PACIFICVIS2009},
  doi = {10.1109/PACIFICVIS.2009.4906841}
}

@INPROCEEDINGS{Shneiderman2001,
  author = {Ben Shneiderman and Martin Wattenberg},
  title = {Ordered {Treemap} Layouts},
  pages = {73--78},
  abstract = {Treemaps, a space-filling method of visualizing large hierarchical
	data sets, are receiving increasing attention. Several algorithms
	have been proposed to create more useful displays by controlling
	the aspect ratios of the rectangles that make up a treemap. While
	these algorithms do improve visibility of small items in a single
	layout, they introduce instability over time in the display of dynamically
	changing data, and fail to preserve an ordering of the underlying
	data. This paper introduces the ordered treemap, which addresses
	these two shortcomings. The ordered treemap algorithm ensures that
	items near each other in the given order will be near each other
	in the treemap layout. Using experimental evidence from Monte Carlo
	trials, we show that compared to other layout algorithms ordered
	treemaps are more stable while maintaining relatively favorable aspect
	ratios of the constituent rectangles. A second test set uses stock
	market data.},
  crossref = {INFOVIS2001},
  doi = {10.1109/INFVIS.2001.963283}
}

@INPROCEEDINGS{Slack2005,
  author = {James Slack and Kristian Hildebrand and Tamara Munzner},
  title = {{PRISAD}: A partitioned rendering infrastructure for scalable accordion
	drawing},
  pages = {41--48},
  abstract = {We present PRISAD, the first generic rendering infrastructure for
	information visualization applications that use the accordion drawing
	technique: rubber sheet navigation with guaranteed visibility for
	marked areas of interest. Our new rendering algorithms are based
	on the partitioning of screen space, which allows us to handle dense
	dataset regions correctly. The algorithms in previous work led to
	incorrect visual representations because of overculling, and to inefficiencies
	due to overdrawing multiple items in the same region. Our pixel based
	drawing infrastructure guarantees correctness by eliminating overculling,
	and improves rendering performance with tight bounds on overdrawing.
	PRITree and PRISeq are applications built on PRISAD, with the feature
	sets of TreeJuxtaposer and SequenceJuxtaposer, respectively. We describe
	our PRITree and PRISeq dataset traversal algorithms, which are used
	for efficient rendering, culling, and layout of datasets within the
	PRISAD framework. We also discuss PRITree node marking techniques,
	which offer order-of-magnitude improvements to both memory and time
	performance versus previous range storage and retrieval techniques.
	Our PRITree implementation features a five fold increase in rendering
	speed for nontrivial tree structures, and also reduces memory requirements
	in some real world datasets by up to eight times, so we are able
	to handle trees of several million nodes. PRISeq renders fifteen
	times faster and handles datasets twenty times larger than previous
	work.},
  crossref = {INFOVIS2005},
  doi = {10.1109/INFVIS.2005.1532127}
}

@INPROCEEDINGS{Slack2003,
  author = {James Slack and Tamara Munzner and Fran\c{c}ois Guimbreti\'ere},
  title = {{TreeJuxtaposer} {InfoVis} Contest Entry},
  pages = {118--119},
  abstract = {TreeJuxtaposer is a tool for interactive side-by-side tree comparison.
	Its two key innovations are the automatic marking of topological
	structural differences, and the guaranteed visibility of marked items.
	It uses the AccordionDrawer approach for layout and navigation, a
	multifocus global Focus+Context approach where stretching one part
	of the tree or screen causes the rest to shrink, and vice versa.
	Progressive rendering guarantees immediate interactive response even
	for large trees.},
  crossref = {INFOVISposter2003},
  url = {http://www.cs.ubc.ca/~tmm/papers/contest03/contest.pdf}
}

@INPROCEEDINGS{Song2002,
  author = {Hongzhi Song and Edwin P. Curran and Roy Sterritt},
  title = {{FlexTree}: Visualising large quantities of hierarchical information},
  abstract = {Visualising large quantities of hierarchical information is a difficult
	topic in information visualisation and it has been attracting much
	effort since the emergence of this research area. The paper presents
	the FlexTree, an approach to visualising, navigating and analysing
	large hierarchies. It is based on the focus+context technique and
	combines the power of the histogram with traditional two dimensional
	(2D) node-link diagrams. This approach maintains the context of a
	large hierarchy while providing easy and consistent access to details
	of multiple focal points. Simple aesthetic rules and an interactive
	design were applied to the system. As a demonstration of the approach
	a computer file system hierarchy with 6,351 file folders and 130,400
	files on a personal computer has been successfully visualised.},
  crossref = {SMC2002}
}

@INPROCEEDINGS{Song2006,
  author = {Hongzhi Song and Yu Qi and Lei Xiao and Tonglin Zhu and Edwin P.
	Curran},
  title = {{LensTree}: Browsing and Navigating Large Hierarchical Information
	Structures},
  pages = {682--687},
  abstract = {This paper presents LensTree, a novel browsing and navigation tool
	for large hierarchical information structures. It enhances traditional
	indented lists by applying focus+context view to its design. LensTree
	dynamically changes the sizes of nodes to provide a focal area around
	the mouse pointer while keeping nodes in the peripheral area in smaller
	sizes as context. This enables it to display a larger hierarchy than
	traditional indented lists within the same screen area. Therefore
	scrolling and expanding/collapsing are less often used so that it
	is more efficient for performing browsing and navigation tasks. An
	informal user test was conducted and the users showed strong interest
	to LensTree's visual presentation. It suggested that this technique
	was worth further exploitation.},
  crossref = {ICAT2006},
  doi = {10.1109/ICAT.2006.81}
}

@INPROCEEDINGS{Stasko2000,
  author = {John Stasko and Eugene Zhang},
  title = {Focus+Context Display and Navigation Techniques for Enhancing Radial,
	Space-Filling Hierarchy Visualizations},
  pages = {57--65},
  abstract = {Radial, space-filling visualizations can be useful for depicting information
	hierarchies, but they suffer from one major problem. As the hierarchy
	grows in size, many items become small, peripheral slices that are
	difficult to distinguish. We have developed three visualization/interaction
	techniques that provide flexible browsing of the display. The techniques
	allow viewers to examine the small items in detail while providing
	context within the entire information hierarchy. Additionally, smooth
	transitions between views help users maintain orientation within
	the complete information space.},
  crossref = {INFOVIS2000},
  doi = {10.1109/INFVIS.2000.885091}
}

@INPROCEEDINGS{Steinbruckner2010,
  author = {Frank Steinbr\"uckner and Claus Lewerentz},
  title = {Representing development history in software cities},
  pages = {193--202},
  abstract = {In this paper we describe a systematic approach to utilize the city
	metaphor for the visualization of large software systems as evolving
	software cities. The main contribution is a new layout approach which
	explicitly takes the development history of software systems into
	account and makes history directly visible in the layouts. These
	layouts incrementally evolve in a very smooth and stable way during
	the development of the represented software system. They are used
	as a visualization platform for integrating a large variety of product
	and process data and thus create a coherent set of specialized visualizations.
	To illustrate this we present some example maps capturing specific
	development history aspects.},
  crossref = {SOFTVIS2010},
  doi = {10.1145/1879211.1879239}
}

@INPROCEEDINGS{Sun2003a,
  author = {Lisong Sun and Steve Smith and Thomas Preston Caudell},
  title = {{FROTH} -- A force-directed representation of tree hierarchies},
  pages = {108--109},
  abstract = {FROTH is the implementation of a low complexity force-directed tree
	layout algorithm based on the Lennard-Jones potential. The recursive
	method lays out sub-trees as small disks contained in their parent
	disk. Inside each disk, children disks are dynamically laid out using
	a new force directed simulation. Unlike most other force-directed
	layout methods which run in quadratic time for each simulation step,
	this algorithm runs in $O(n^{m+1/m})$ time per each step for a tree
	with $n$ nodes, depth $m$ and all the nodes having uniform number
	of children. The layout uses space efficiently and reflects both
	global structure and local detail. The method supports runtime insertion
	and deletion. Both operations and the evolving process are rendered
	with smooth animation to preserve visual continuity. The method could
	be used to monitor in real time, visualize and analyze a wide variety
	of data which has a rooted tree structure, e.g. internet hosts could
	be laid out by domain name (DNS) hierarchies.},
  crossref = {INFOVISposter2003},
  url = {http://conferences.computer.org/infovis/files/compendium2003.pdf}
}

@INPROCEEDINGS{Tanaka2003,
  author = {Yoichi Tanaka and Yoshihiro Okada and Koichi Niijima},
  title = {Treecube: Visualization Tool for Browsing {3D} Multimedia Data},
  pages = {427--432},
  abstract = {This paper proposes a new 3D visualization tool for hierarchical information.
	A 2D visualization tool for hierarchical information called treemap
	has already been proposed by Ben Shneiderman, et al. in 1992. In
	general, hierarchical information is represented as a tree structure.
	Treemap hierarchically lays out each node as a bounding box, whose
	size is the same as the specific weight or attribute value of the
	node. After the original treemap algorithm called slice-and-dice,
	some extensions to it have been proposed: squarified treemap, ordered
	treemap and strip treemap. Furthermore, quantum treemap is a quantization
	version of these extensions. In this paper, the authors propose a
	new 3D visualization tool for hierarchical information called treecube
	that can be taken as a 3D extension of treemap. Especially, this
	paper shows its usefulness for browsing 3D multimedia data, i.e.,
	2D images, 3D shape models, motion data, etc., originally stored
	in a file system.},
  crossref = {IV2003},
  doi = {10.1109/IV.2003.1218020}
}

@INPROCEEDINGS{Tanaka2004,
  author = {Yoichi Tanaka and Yoshihiro Okada and Koichi Niijima},
  title = {Interactive Interfaces of Treecube for Browsing {3D} Multimedia Data},
  pages = {298--302},
  abstract = {The authors of this paper have already proposed Treecube which is
	a visualization tool for browsing 3D multimedia data. In this paper,
	the authors also propose its interactive interfaces for efficiently
	browsing 3D multimedia data. Treecube is regarded as a 3D extension
	of treemap, which is a visualization tool for hierarchical information
	proposed by Ben Shneiderman et al. in 1992. For treemap, there are
	several layout algorithms: slice-and-dice, ordered treemap, strip
	treemap and so on. Furthermore, quantum treemap exists. It means
	a quantization version of these treemap layout algorithms. The authors
	implemented mainly three layout algorithms, i.e., slice-and-dice,
	ordered and strip treecube algorithm, and implemented their quantization
	version. Practically sophisticated interfaces are necessary for efficiently
	browsing 3D multimedia data. In this paper, the authors also propose
	such interfaces. The authors implemented mainly five interface functionalities
	for the following operations. (1) "Cutting plane" concept to solve
	the occlusion problem, i.e., nodes located before the plane are hidden
	to make it easy to see inside nodes. (2) The control of node frames,
	i.e., their brightness and thickness, for easily understanding the
	hierarchical structure of nodes. (3) Standard operations for the
	translation and the rotation of an eye position, and for the zoom
	in/out. (4) Particular operations for the extraction of the user
	focus node and for the backward/forward for browsing such node. The
	authors also implemented (5) a function to assign color information
	to any node properties because color is the most important factor
	of the visual display properties.},
  crossref = {AVI2004},
  doi = {10.1145/989863.989914}
}

@INPROCEEDINGS{Tekusova2008a,
  author = {Tatiana Tekusova and Martin Knuth and Tobias Schreck and J\"orn Kohlhammer},
  title = {Data Quality Visualization for Multivariate Hierarchic Data},
  year = {2008},
  abstract = {In many business applications, decision makers often have to base
	their decisions on large amounts of data from various sources. Often,
	the quality of this data varies substantially, affecting the degree
	of certainty the analyst can put into the analyzed data values. The
	data quality measures may be of qualitative or quantitative nature,
	and consist of one or many dimensions. In this poster paper, we first
	present a brief survey of currently available uncertainty visualization
	techniques. We then present experimental results we obtained with
	several techniques for visualization of multidimensional data quality
	information, applied on multivariate hierarchic data used in an economic
	data analysis scenario.},
  crossref = {INFOVISposter2008},
  url = {https://cms.uni-konstanz.de/fileadmin/informatik/ag-schreck/PublicPublications/inproceedings/infovis08-paper.pdf}
}

@INPROCEEDINGS{Tekusova2008,
  author = {Tatiana Tekusova and Tobias Schreck},
  title = {Visualizing Time-Dependent Data in Multivariate Hierarchic Plots
	-- Design and Evaluation of an Economic Application},
  pages = {143-150},
  abstract = {For successfully competing in a modern economy, large amounts of hierarchic
	time-dependent data need to be analyzed. As an example, one could
	consider the geographic composition of inflation in the European
	Union, or the revenue by product (sub) categories of a firm in the
	last month. Analysts wish to interpret the structure of the data
	not only at a single point in time, but examine the changes in the
	data categories through time. The analysts may need to consider additional
	dimensions to composition and time, such as the growth rate or profit
	rate. To reflect such analytic requirements, we have developed an
	interactive visualization of multi-dimensional, structured data taking
	the time dimension into account. The data are displayed in a three
	dimensional hierarchic circular or column plot. The time dimension
	of the data is represented by animation. Our system provides interactive
	tools for the visual data analysis and variable set-up of the data
	display. For better orientation in the data space, we have enhanced
	the visualization with smooth transitions between different data
	selections in case of 3D hierarchic plots. The techniques presented
	can be applied to various data domains. A user study using European
	inflation data has shown the usefulness for effective economic analysis.},
  crossref = {IV2008},
  doi = {10.1109/IV.2008.51}
}

@INPROCEEDINGS{Teoh2002,
  author = {Soon Tee Teoh and Kwan-Liu Ma},
  title = {{RINGS}: A Technique for Visualizing Large Hierarchies},
  pages = {51--73},
  abstract = {We present RINGS, a technique for visualizing large trees. We introduce
	a new ringed circular layout of nodes to make more efficient use
	of limited display space. RINGS provides the user with the means
	to specify areas of primary andsecond ary focus, andis able to show
	multiple foci without compromising understanding of the graph. The
	strength of RINGS is its ability to show more area in focus andmore
	contextual information than existing techniques. We demonstrate the
	effectiveness of RINGS by applying it to the visualization of a Unix
	file directory.},
  crossref = {GD2002},
  doi = {10.1007/3-540-36151-0_25}
}

@INPROCEEDINGS{Tick1992,
  author = {Evan Tick and Daesun Park},
  title = {Kaleidoscope visualization of fine-grain parallel programs},
  year = {1992},
  editor = {Bruce D. Shriver},
  volume = {2},
  pages = {137--148},
  abstract = {A software visualization tool is described that transforms program
	execution trace data from a multiprocessor into a single, color image.
	The image is essentially the program's logical procedure-invocation
	tree, displayed radially from the root. An algorithm is described
	that condenses the image both radially and laterally, producing a
	color-dense abstraction of the program's execution behavior: a program
	signature, within a workstation window. An implementation of the
	tool was made in X-Windows, including a user interface that can zoom
	the image and annotate any node in the image with the corresponding
	procedure-invocation data. Experimentation with the system was performed
	with trace data from Panda, a concurrent logic programming system
	on shared-memory multiprocessors. The authors demonstrate how the
	tool helps the programmer develop intuitions about parallel performance
	and how condensation successfully abstracts very large traces.},
  crossref = {HICSS1992},
  doi = {10.1109/HICSS.1992.183287}
}

@INPROCEEDINGS{Tominski2006,
  author = {Christian Tominski and James Abello and Frank van Ham and Heidrun
	Schumann},
  title = {Fisheye Tree Views and Lenses for Graph Visualization},
  pages = {17--24},
  abstract = {We present interactive visual aids to support the exploration and
	navigation of graph layouts. They include fisheye tree views and
	composite lenses. These views provide, in an integrated manner, overview+detail
	and focus+context. Fisheye tree views are novel applications of the
	well known fisheye distortion technique. They facilitate the exploration
	of the hierarchy trees associated with clustered graphs. Composite
	lenses are the result of the integration of several lens techniques.
	They facilitate the display of local graph information that may be
	otherwise difficult to grasp in large and dense graph layouts},
  crossref = {IV2006},
  doi = {10.1109/IV.2006.54}
}

@INPROCEEDINGS{Turo1992,
  author = {David Turo and Brian Johnson},
  title = {Improving the visualization of hierarchies with treemaps: Design
	Issues and Experimentation},
  pages = {124--131},
  abstract = {Controlled experiments with novice treemap users and real data highlight
	the strengths of treemaps and provide direction for improvement.
	Issues discussed include experimental results, layout algorithms,
	nesting offsets, labeling, animation, and small multiple displays.
	Treemaps prove to be a potent tool for hierarchy display. The principles
	discussed are applicable to many information visualization situations.},
  crossref = {VIS1992},
  doi = {10.1109/VISUAL.1992.235217}
}

@INPROCEEDINGS{Venolia2003,
  author = {Gina Danielle Venolia and Carman Neustaedter},
  title = {Understanding sequence and reply relationships within email conversations:
	a mixed-model visualization},
  pages = {361--368},
  abstract = {It has been proposed that email clients could be improved if they
	presented messages grouped into conversations. An email conversation
	is the tree of related messages that arises from the use of the reply
	operation. We propose two models of conversation. The first model
	characterizes a conversation as a chronological sequence of messages;
	the second as a tree based on the reply relationship. We show how
	existing email clients and prior research projects implicitly support
	each model to a greater or lesser degree depending on their design,
	but none fully supports both models simultaneously. We present a
	mixed-model visualization that simultaneously presents sequence and
	reply relationships among the messages of a conversation, making
	both visible at a glance. We describe the integration of the visualization
	into a working prototype email client. A usability study indicates
	that the system meets our usability goals and verifies that the visualization
	fully conveys both types of relationships within the messages of
	an email conversation.},
  crossref = {CHI2003},
  doi = {10.1145/642611.642674}
}

@INPROCEEDINGS{Verbeek2011,
  author = {Kevin Verbeek and Kevin Buchin and Bettina Speckmann},
  title = {Angle-Restricted {Steiner} Arborescences for {Flow Map} Layout},
  pages = {250--259},
  abstract = {We introduce a new variant of the geometric Steiner arborescence problem,
	motivated by the layout of flow maps. Flow maps show the movement
	of objects between places. They reduce visual clutter by bundling
	lines smoothly and avoiding self-intersections. To capture these
	properties, our angle-restricted Steiner arborescences, or flux trees,
	connect several targets to a source with a tree of minimal length
	whose arcs obey a certain restriction on the angle they form with
	the source. We study the properties of optimal flux trees and show
	that they are planar and consist of logarithmic spirals and straight
	lines. Flux trees have the shallow-light property. We show that computing
	optimal flux trees is NP-hard. Hence we consider a variant of flux
	trees which uses only logarithmic spirals. Spiral trees approximate
	flux trees within a factor depending on the angle restriction. Computing
	optimal spiral trees remains NP-hard, but we present an efficient
	2-approximation, which can be extended to avoid "positive monotone"'
	obstacles.},
  crossref = {ISAAC2011},
  doi = {10.1007/978-3-642-25591-5_27}
}

@INPROCEEDINGS{Vernier2002,
  author = {Frederic Vernier and Neal Lesh and Chia Shen},
  title = {Visualization techniques for circular tabletop interfaces},
  pages = {257--265},
  abstract = {This paper presents visualization and layout schemes developed for
	a novel circular user interface designed for a round, tabletop display.
	Since all the displayed items are in a polar coordinate system, many
	interface and visualization schemes must be revisited to account
	for this new layout of UI elements. We discuss the direct implications
	of such a circular interface on document orientation. We describe
	two types of fisheye deformation of the circular layout and explain
	how to use them in a multi-person collaborative interface. These
	two schemes provide a general layout framework for circular interfaces.
	We have also designed a new visualization technique derived from
	the particularities of the circular layout we have highlighted. In
	this technique the user controls the layout of the elements of a
	hierarchical tree. Our approach is to provide the user rich interaction
	possibilities to easily and quickly produce a layout comparable to
	the hyperbolic view developed at Xerox PARC. The visualization work
	presented in this paper is part of our ongoing Personal Digital Historian
	(PDH) research project. The overall goal of PDH is to investigate
	ways to effectively and intuitively organize, navigate, browse, present
	and visualize digital data in an interactive multi-person conversational
	setting.},
  crossref = {AVI2002},
  doi = {10.1145/1556262.1556305}
}

@INPROCEEDINGS{Wang2006a,
  author = {Taowei David Wang and Bijan Parsia},
  title = {{CropCircles}: Topology Sensitive Visualization of {OWL} Class Hierarchies},
  pages = {695-708},
  abstract = {OWL ontologies present many interesting visualization challenges.
	Here we present CropCircles, a technique designed to view the class
	hierarchies in ontologies as trees. We place special emphasis on
	topology understanding when designing the tool. We drew inspiration
	from treemaps, but made substantial changes in the representation
	and layout. Most notably, the spacefillingness of treemap is relaxed
	in exchange for visual clarity. We outline the problem scape of visualizing
	ontology hierarchies, note the requirements that go into the design
	of the tool, and discuss the interface and implementation. Finally,
	through a controlled experiment involving tasks common to understanding
	ontologies, we show the benefits of our design.},
  crossref = {ISWC2006},
  doi = {10.1007/11926078_50}
}

@INPROCEEDINGS{Wang2006,
  author = {Weixin Wang and Hui Wang and Guozhong Dai and Hongan Wang},
  title = {Visualization of Large Hierarchical Data by Circle Packing},
  pages = {517--520},
  abstract = {In this paper a novel approach is described for tree visualization
	using nested circles. The brother nodes at the same level are represented
	by externally tangent circles; the tree nodes at different levels
	are displayed by using 2D nested circles or 3D nested cylinders.
	A new layout algorithm for tree structure is described. It provides
	a good overview for large data sets. It is easy to see all the branches
	and leaves of the tree. The new method has been applied to the visualization
	of file systems.},
  crossref = {CHI2006},
  doi = {10.1145/1124772.1124851}
}

@INPROCEEDINGS{Wattenberg1999,
  author = {Martin Wattenberg},
  title = {Visualizing the stock market},
  pages = {188--189},
  abstract = {We describe a new 2-dimensional visualization algorithm capable of
	presenting detailed information on hundreds of items while emphasizing
	overall patterns in the data. This display method, which builds on
	Shneiderman's treemap technique, makes use of both hierarchy and
	similarity information. We have implemented this display in the SmartMoney
	Map of the Market, a web page that reports current data on over 500
	publicly traded companies.},
  crossref = {CHIabs1999},
  doi = {10.1145/632716.632834}
}

@INPROCEEDINGS{Wattenberg2005,
  author = {Martin Wattenberg},
  title = {A Note on Space-Filling Visualizations and Space-Filling Curves},
  pages = {181--185},
  abstract = {A recent line of treemap research has focused on layout algorithms
	that optimize properties such as stability, preservation of ordering
	information, and aspect ratio of rectangles. No ideal treemap layout
	algorithm has been found, and so it is natural to explore layouts
	that produce non-rectangular regions. This note describes a connection
	between space-filling visualizations and the mathematics of space-filling
	curves, and uses that connection to characterize a family of layout
	algorithms which produce nonrectangular regions but enjoy geometric
	continuity under changes to the data and legibility even for highly
	unbalanced trees.},
  crossref = {INFOVIS2005},
  doi = {10.1109/INFVIS.2005.1532145}
}

@INPROCEEDINGS{Wattenberg2003,
  author = {Martin Wattenberg and Danyel Fisher},
  title = {A Model of Multi-Scale Perceptual Organization in Information Graphics},
  pages = {23--30},
  abstract = {We propose a new method for assessing the perceptual organization
	of information graphics, based on the premise that the visual structure
	of an image should match the structure of the data it is intended
	to convey. The core of our method is a new formal model of one type
	of perceptual structure, based on classical machine vision techniques
	for analyzing an image at multiple resolutions. The model takes as
	input an arbitrary grayscale image and returns a lattice structure
	describing the visual organization of the image. We show how this
	model captures several aspects of traditional design aesthetics,
	and we describe a software tool that implements the model to help
	designers analyze and refine visual displays. Our emphasis here is
	on demonstrating the model's potential as a design aid rather than
	as a description of human perception, but given its initial promise
	we propose a variety of ways in which the model could be extended
	and validated.},
  crossref = {INFOVIS2003},
  doi = {10.1109/INFVIS.2003.1249005}
}

@INPROCEEDINGS{Wesson2004,
  author = {Janet Wesson and MC du Plessis and Craig Oosthuizen},
  title = {A {ZoomTree} interface for searching genealogical information},
  pages = {131--136},
  abstract = {Genealogical information systems (GIS) typically contain large amounts
	of information about families and relationships between family members.
	Most existing GIS have textual, form-based interfaces for searching
	and browsing family information. These interfaces do not support
	dynamic browsing and manipulation of family trees. This paper discusses
	the design and development of a novel interface, called ZoomTree,
	for WINGIS (the GIS developed at UPE), to facilitate dynamic exploration
	and browsing of family tree information.},
  crossref = {AFRIGRAPH2004},
  doi = {10.1145/1029949.1029974}
}

@INPROCEEDINGS{Wettel2008a,
  author = {Richard Wettel},
  title = {Scripting {3D} Visualizations with {CodeCity}},
  abstract = {Software visualization is a useful means to present and explore large
	amounts of information. However, constructing useful visualizations
	targeted at specific tasks is often a trial-and-error process. As
	a consequence, a visualization prototyping tools needs to be flexible
	to allow for the creation of new visualizations and also to provide
	an environment that grants access to its powerful mechanisms. In
	this paper, we report on our experience with complementing the rich
	graphical user interface of CodeCity, a 3D visualization tool, with
	a scripting environment. The scripting language gives the programmers
	full access to the configurability of our system, without the need
	for them to be exposed to the real complexity of the application.
	Thanks to the scripting engine, adapting CodeCity to new types of
	data has become easy, as we illustrate with examples.},
  crossref = {FAMOOSr2008},
  url = {http://www.inf.usi.ch/phd/wettel/download.php?f=Wettel08e-famoosr.pdf}
}

@INPROCEEDINGS{Wettel2007,
  author = {Richard Wettel and Michele Lanza},
  title = {Visualizing Software Systems as Cities},
  pages = {92--99},
  abstract = {This paper presents a 3D visualization approach which gravitates around
	the city metaphor, i.e., an object-oriented software system is represented
	as a city that can be traversed and interacted with: the goal is
	to give the viewer a sense of locality to ease program comprehension.
	The key point in conceiving a realistic software city is to map the
	information about the source code in meaningful ways in order to
	take the approach beyond beautiful pictures. We investigated several
	concepts that contribute to the urban feeling, such as appropriate
	layouts, topology, and facilities to ease navigation and interaction.
	We experimented our approach on a number of systems, and present
	our findings.},
  crossref = {VISSOFT2007},
  doi = {10.1109/VISSOF.2007.4290706}
}

@INPROCEEDINGS{Wettel2008,
  author = {Richard Wettel and Michele Lanza},
  title = {Visually localizing design problems with disharmony maps},
  pages = {155--164},
  abstract = {Assessing the quality of software design is difficult, as "design"
	is expressed through guidelines and heuristics, not rigorous rules.
	One successful approach to assess design quality is based on detection
	strategies, which are metrics-based composed logical conditions,
	by which design fragments with specific properties are detected in
	the source code. Such detection strategies, when executed on large
	software systems usually return large sets of artifacts, which potentially
	exhibit one or more "design disharmonies", which are then inspected
	manually, a cumbersome activity. In this article we present disharmony
	maps, a visualization-based approach to locate such flawed software
	artifacts in large systems. We display the whole system using a 3D
	visualization technique based on a city metaphor. We enrich such
	visualizations with the results returned by a number of detection
	strategies, and thus render both the static structure and the design
	problems that affect a subject system. We evaluate our approach on
	a number of open-source Java systems and report on our findings.},
  crossref = {SOFTVIS2008},
  doi = {10.1145/1409720.1409745}
}

@INPROCEEDINGS{Wijk1999,
  author = {Jarke J. van Wijk and Huub van de Wetering},
  title = {Cushion {Treemaps}: Visualization of Hierarchical Information},
  pages = {73--78},
  abstract = {A new method is presented for the visualization of hierarchical information,
	such as directory structures and organization structures. Cushion
	treemaps inherit the elegance of standard treemaps: compact, space-filling
	displays of hierarchical information, based on recursive subdivision
	of a rectangular image space. Intuitive shading is used to provide
	insight in the hierarchical structure.During the subdivision ridges
	are added per rectangle, which are rendered with a simple shading
	model. The result is a surface that consists of recursive cushions.
	The method is efficient, effective, easy to use and implement, and
	has a wide applicability.},
  crossref = {INFOVIS1999},
  doi = {10.1109/INFVIS.1999.801860}
}

@INPROCEEDINGS{Wilson1999,
  author = {Richard M. Wilson and R. Daniel Bergeron},
  title = {Dynamic hierarchy specification and visualization},
  pages = {65--72},
  abstract = {This paper describes concepts that underlie the design and implementation
	of an information exploration system that allows users to impose
	arbitrary hierarchical organizations on their data. Such hierarchies
	allow a user to embed important semantic information into the hierarchy
	definition. Our goal is to recognize the significance of this implicit
	information and to utilize it in the hierarchy visualization. The
	innovative features of our system include the dynamic modification
	of the hierarchy definitions and the definition and implementation
	of a set of layout algorithms that utilize semantic information implicit
	in the tree construction.},
  crossref = {INFOVIS1999},
  doi = {10.1109/INFVIS.1999.801859}
}

@INPROCEEDINGS{Workman2004,
  author = {David Workman and Margaret Bernard and Steven Pothoven},
  title = {An Incremental Editor for Dynamic Hierarchical Drawing of Trees},
  pages = {986--995},
  abstract = {We present an incremental tree editor based on algorithms for manipulating
	shape functions. The tree layout is hierarchical, left-to-right.
	Nodes of variable size and shape are supported. The paper presents
	algorithms for basic tree editing operations, including cut and paste.
	The layout algorithm for positioning child-subtrees rooted at a given
	parent is incrementally recomputed with each edit operation; it attempts
	to conserve the total display area allocated to child-subtrees while
	preserving the user’s mental map. The runtime and space efficiency
	is good as a result of exploiting a specially designed Shape abstraction
	for encoding and manipulating the geometric boundaries of subtrees
	as monotonic step functions to determine their best placement. All
	tree operations, including loading, saving trees to files, and incremental
	cut and paste, are worst case O(N) in time, but typically cut and
	paste are O(log(N)2), where N is the number of nodes.},
  crossref = {ICCS2004},
  doi = {10.1007/978-3-540-24688-6_126}
}

@INPROCEEDINGS{Wu2007,
  author = {Liang-Hong Wu and Ping-Yu Hsu},
  title = {The Perceptual Eye View: A User-Defined Method for Information Visualization},
  pages = {181--190},
  abstract = {With the growing volumes of data, exploring the relationships within
	the huge amounts of data is difficult. Information visualization
	uses the human perception system to assist users in analyzing complex
	relationships and graphical hierarchy trees used commonly to present
	the relationship among the data. Conventional information visualization
	approaches fail to consider human factors, they only provide fixed
	degree of detail to different users. However, different users have
	different perceptions. A well-known information visualization called
	'Magic Eye View' uses a three-dimensional interaction to allow the
	user to control the degree of detail he would like. However, it fails
	to consider some important focus+context features such as the smooth
	transition of the focus region and the global context. In this paper,
	we propose a novel information visualization method, called the 'Perceptual
	Eye View,' by which users may control the focus points three-dimensionally
	enabling different users to view their user-defined degree of detail
	of information space and to perceive based on their own knowledge
	and perception. The results demonstrate that our proposed method
	improve the 'Magic Eye View' by providing smooth transition of the
	focus region and the global context, which are important focus+context
	features that the 'Magic Eye View' fails to consider.},
  crossref = {HCII2007},
  doi = {10.1007/978-3-540-73107-8_20}
}

@INPROCEEDINGS{Yamaguchi2003,
  author = {Yumi Yamaguchi and Takayuki Itoh},
  title = {Visualization of Distributed Processes Using {Data Jewelry Box} Algorithm},
  pages = {162--169},
  abstract = {Visualization of distributed processes is useful for the management
	of large-scale distributed computing systems. Reactivity and scalability
	are especially important requirements for such visualization of distributed
	processes. We have proposed the visualization technique "Data Jewelry
	Box" algorithm, which satisfies both of the above requirements. The
	technique can be applied for the visualization of distributed processes,
	however, the algorithm has a problem that may yield much different
	data layouts even among very similar datasets. This is a serious
	issue for the seamless visualization of time-varying data. To solve
	the problem, we propose the extension of "Data Jewelry Box" algorithm.
	The extension places data elements referring positions of the previous
	data layout, so that the extension can yield similar layouts among
	similar datasets. We introduce the extended algorithm, and propose
	the visualization system for distributed computing systems using
	the extended algorithm.},
  crossref = {CGI2003},
  doi = {10.1109/CGI.2003.1214461}
}

@INPROCEEDINGS{Yang2002,
  author = {Jing Yang and Matthew O. Ward and Elke A. Rundensteiner},
  title = {{InterRing}: An Interactive Tool for Visually Navigating and Manipulating
	Hierarchical Structures},
  pages = {77--84},
  abstract = {Radial, space-filling (RSF) techniques for hierarchy visualization
	have several advantages over traditional node-link diagrams, including
	the ability to efficiently use the display space while effectively
	conveying the hierarchy structure. Several RSF systems and tools
	have been developed to date, each with varying degrees of support
	for interactive operations such as selection and navigation. We describe
	what we believe to be a complete set of desirable operations on hierarchical
	structures. We then present InterRing, an RSF hierarchy visualization
	system that supports a significantly more extensive set of these
	operations than prior systems. In particular, InterRing supports
	multi-focus distortions, interactive hierarchy reconfiguration, and
	both semi-automated and manual selection. We show the power and utility
	of these and other operations, and describe our on-going efforts
	to evaluate their effectiveness and usability.},
  crossref = {INFOVIS2002},
  doi = {10.1109/INFVIS.2002.1173151}
}

@INPROCEEDINGS{Zhao2005,
  author = {Shengdong Zhao and Michael J. McGuffin and Mark H. Chignell},
  title = {Elastic Hierarchies: Combining {Treemaps} and node-link diagrams},
  pages = {57--64},
  abstract = {We investigate the use of elastic hierarchies for representing trees,
	where a single graphical depiction uses a hybrid mixture, or "interleaving",
	of more basic forms at different nodes of the tree. In particular,
	we explore combinations of node link and treemap forms, to combine
	the space efficiency of treemaps with the structural clarity of node
	link diagrams. A taxonomy is developed to characterize the design
	space of such hybrid combinations. A software prototype is described,
	which we used to explore various techniques for visualizing, browsing
	and interacting with elastic hierarchies, such as side by side overview
	and detail views, highlighting and rubber banding across views, visualization
	of multiple foci, and smooth animations across transitions. The paper
	concludes with a discussion of the characteristics of elastic hierarchies
	and suggestions for research on their properties and uses.},
  crossref = {INFOVIS2005},
  doi = {10.1109/INFVIS.2005.1532129}
}

@ARTICLE{Aborisade2010,
  author = {D. O. Aborisade and Olanrewaju Jelili Oyelade},
  title = {{HierarchyMap}: A Novel Approach to {Treemap} Visualization of Hierarchical
	Data},
  journal = {Global Journal of Computer Science and Technology},
  year = {2010},
  volume = {9},
  pages = {77--81},
  number = {5 v.2},
  month = {January},
  abstract = {The HierarchyMap describes a novel approach for Treemap Visualization
	method for representing large volume of hierarchical information
	on a 2-dimensional space. HierarchyMap algorithm is a new ordered
	treemap algorithm. Results of the implementation of HierarchyMap
	treemap algorithm show that it is capable of representing several
	thousands of hierarchical data on 2-dimensional space on a computer
	and Portable Device Application (PDA) screens while still maintaining
	the qualities found in existing treemap algorithms such as readability,
	low aspect ratio, reduced run time, and reduced number of thin rectangles.
	The HierarchyMap treemap algorithm is implemented in Java programming
	language and tested with dataset of Departmental and Faculty systems
	of Universities, Family trees, Plant and Animal taxonomy structures.},
  url = {http://computerresearch.org/stpr/index.php/gjcst/article/viewArticle/96}
}

@ARTICLE{Allen2002,
  author = {Maryellen Mott Allen},
  title = {The Hype Over Hyperbolic Browsers},
  journal = {Online},
  year = {2002},
  volume = {26},
  pages = {20--28},
  number = {3},
  month = {May+June},
  abstract = {Considers complaints about the usability in the human-computer interaction
	aspect of information retrieval and discusses information visualization,
	the Online Library of Information Visualization Environments, hyperbolic
	information structure, subject searching, real-world applications,
	relational databases and hyperbolic trees, and the future of visual
	information structures.},
  url = {http://www.onlinemag.net/may02/allen.htm}
}

@ARTICLE{Andrews2002,
  author = {Keith Andrews and Wolfgang Kienreich and Vedran Sabol and Jutta Becker
	and Georg Droschl and Frank Kappe and Michael Granitzer and Peter
	Auer and Klaus Tochtermann},
  title = {The {InfoSky} visual explorer: Exploiting hierarchical structure
	and document similarities},
  journal = {Information Visualization},
  year = {2002},
  volume = {1},
  pages = {166--181},
  number = {3/4},
  abstract = {InfoSky is a system enabling users to explore large, hierarchically
	structured document collections. Similar to a real-world telescope,
	InfoSky employs a planar graphical representation with variable magnification.
	Documents of similar content are placed close to each other and are
	visualised as stars, forming clusters with distinct shapes. For greater
	performance, the hierarchical structure is exploited and force-directed
	placement is applied recursively at each level on much fewer objects,
	rather than on the whole corpus. Collections of documents at a particular
	level in the hierarchy are visualised with bounding polygons using
	a modified weighted Voronoi diagram. Their area is related to the
	number of documents contained. Textual labels are displayed dynamically
	during navigation, adjusting to the visualisation content. Navigation
	is animated and provides a seamless zooming transition between summary
	and detail view. Users can map metadata such as document size or
	age to attributes of the visualisation such as colour and luminance.
	Queries can be made and matching documents or collections are highlighted.
	Formative usability testing is ongoing; a small baseline experiment
	comparing the telescope browser to a tree browser is discussed.},
  doi = {10.1057/palgrave.ivs.9500023}
}

@ARTICLE{Aydin2011,
  author = {Burcu Aydin and Gabor Pataki and Haonan Wang and Alim Ladha and Elizabeth
	Bullitt and J.S. Marron},
  title = {Visualizing the Structure of Large Trees},
  journal = {Electronic Journal of Statistics},
  year = {2011},
  volume = {5},
  pages = {405--420},
  abstract = {This study introduces a new method of visualizing complex tree structured
	objects. The usefulness of this method is illustrated in the context
	of detecting unexpected features in a data set of very large trees.
	The major contribution is a novel two-dimensional graphical representation
	of each tree, with a covariate coded by color. The motivating data
	set contains three dimensional representations of brain artery systems
	of 105 subjects. Due to inaccuracies inherent in the medical imaging
	techniques, issues with the reconstruction algo- rithms and inconsistencies
	introduced by manual adjustment, various discrepancies are present
	in the data. The proposed representation enables quick visual detection
	of the most common discrepancies. For our driving example, this tool
	led to the modification of 10% of the artery trees and deletion of
	6.7%. The benefits of our cleaning method are demonstrated through
	a statistical hypothesis test on the effects of aging on vessel structure.
	The data cleaning resulted in improved significance levels.},
  url = {http://projecteuclid.org/euclid.ejs/1305034908}
}

@ARTICLE{Aydin2010,
  author = {Burcu Aydin and Gabor Pataki and Haonan Wang and Alim Ladha and Elizabeth
	Bullitt and J.S. Marron},
  title = {Visualizing the structure of large trees},
  journal = {arXiv.org e-print service},
  year = {2010},
  volume = {1001.0951v2},
  abstract = {This study introduces a new method of visualizing complex tree structured
	objects. The usefulness of this method is illustrated in the context
	of detecting unexpected features in a data set of very large trees.
	The major contribution is a novel two-dimensional graphical representation
	of each tree, with a covariate coded by color. The motivating data
	set contains three dimensional representations of brain artery systems
	of 105 subjects. Due to inaccuracies inherent in the medical imaging
	techniques, issues with the reconstruction algo- rithms and inconsistencies
	introduced by manual adjustment, various discrepancies are present
	in the data. The proposed representation enables quick visual detection
	of the most common discrepancies. For our driving example, this tool
	led to the modification of 10\% of the artery trees and deletion
	of 6.7\%. The benefits of our cleaning method are demonstrated through
	a statistical hypothesis test on the effects of aging on vessel structure.
	The data cleaning resulted in improved significance levels.},
  url = {http://arxiv.org/abs/1001.0951v2}
}

@ARTICLE{Bagheri2005,
  author = {Alireza Bagheri and Mohammadreza Razzazi},
  title = {How to draw free trees inside bounded simple polygons},
  journal = {Journal of Universal Computer Science},
  year = {2005},
  volume = {11},
  pages = {804--829},
  number = {6},
  abstract = {In this paper we investigate polyline grid drawing of free trees on
	2D grids which are bounded by simple polygons. We focus on achieving
	uniform node distribution while we also try to achieve minimum edge
	crossings. We do not consider achieving symmetry as a mandatory task,
	but our algorithm can exploit some symmetries present in both the
	given trees and the given polygons. To our knowledge, our work is
	the first attempt for developing algorithms that draw graphs on regions
	which are bounded by simple polygons.},
  doi = {10.3217/jucs-011-06-0804}
}

@ARTICLE{Baron1969,
  author = {Margaret E. Baron},
  title = {A Note on the Historical Development of Logic Diagrams: {L}eibniz,
	{E}uler and {V}enn},
  journal = {The Mathematical Gazette},
  year = {1969},
  volume = {53},
  pages = {113--125},
  number = {384},
  doi = {10.2307/3614533}
}

@ARTICLE{Bederson2002,
  author = {Benjamin B. Bederson and Ben Shneiderman and Martin Wattenberg},
  title = {Ordered and quantum treemaps: Making effective use of {2D} space
	to display hierarchies},
  journal = {ACM Transactions on Graphics},
  year = {2002},
  volume = {21},
  pages = {833--854},
  number = {4},
  abstract = {Treemaps, a space-filling method for visualizing large hierarchical
	data sets, are receiving increasing attention. Several algorithms
	have been previously proposed to create more useful displays by controlling
	the aspect ratios of the rectangles that make up a treemap. While
	these algorithms do improve visibility of small items in a single
	layout, they introduce instability over time in the display of dynamically
	changing data, fail to preserve order of the underlying data, and
	create layouts that are difficult to visually search. In addition,
	continuous treemap algorithms are not suitable for displaying fixed-sized
	objects within them, such as images.This paper introduces a new "strip"
	treemap algorithm which addresses these shortcomings, and analyzes
	other "pivot" algorithms we recently developed showing the trade-offs
	between them. These ordered treemap algorithms ensure that items
	near each other in the given order will be near each other in the
	treemap layout. Using experimental evidence from Monte Carlo trials
	and from actual stock market data, we show that, compared to other
	layout algorithms, ordered treemaps are more stable, while maintaining
	relatively favorable aspect ratios of the constituent rectangles.
	A user study with 20 participants clarifies the human performance
	benefits of the new algorithms. Finally, we present quantum treemap
	algorithms, which modify the layout of the continuous treemap algorithms
	to generate rectangles that are integral multiples of an input object
	size. The quantum treemap algorithm has been applied to PhotoMesa,
	an application that supports browsing of large numbers of images.},
  doi = {10.1145/571647.571649}
}

@MISC{Bereiter1999,
  author = {Thomas William Bereiter and Doron Gan},
  title = {Method and apparatus for the viewing and exploration of the content
	of hierarchical information},
  howpublished = {United States Patent US 5917492, filed Mar. 31, 1997, issued Jun.
	29},
  year = {1999},
  abstract = {A method and system are disclosed for displaying a graphical representation
	on a display screen of a data processing system in a manner that
	optimizes screen "real estate" and ease of information viewing. The
	graphical representation may be a tree hierarchy including a plurality
	of expandable and collapsible nodes. The method begins as the hierarchy
	is displayed within a primary display window on the display screen
	when the user selects a node to be expanded . In response, a first
	display region is output within the primary display window and includes
	a set of one or more subnodes associated with the selected node.
	If a first subnode in the first display region is then selected for
	expansion, a second display region is then output within the first
	display region, and the second display region in turn includes a
	set of one or more subnodes of the first subnode. This generation
	of new "nested" display regions then continues as the user continues
	to explore deeper into the tree hierarchy. A given subnode display
	region may have one or more controls, such as a sizing button or
	one or more scroll bars, to facilitate display of node information
	within the region, and preferably each expanded node remains associated
	with its subnode display region using a guideline. If generation
	and display of a subnode display region requires additional screen
	space, one or more of the subnodes in the "parent" display region
	are re-positioned.},
  url = {http://www.freepatentsonline.com/5917492.html}
}

@ARTICLE{Berg2011a,
  author = {Mark de Berg and Bettina Speckmann and Vincent van der Weele},
  title = {Treemaps with Bounded Aspect Ratio},
  journal = {arXiv.org e-print service},
  year = {2011},
  volume = {1012.1749v2},
  abstract = {Treemaps are a popular technique to visualize hierarchical data. The
	input is a weighted tree $\tree$ where the weight of each node is
	the sum of the weights of its children. A treemap for $\tree$ is
	a hierarchical partition of a rectangle into simply connected regions,
	usually rectangles. Each region represents a node of $\tree$ and
	the area of each region is proportional to the weight of the corresponding
	node. An important quality criterium for treemaps is the aspect ratio
	of its regions. Unfortunately, one cannot bound the aspect ratio
	if the regions are restricted to be rectangles. Hence Onak and Sidiropoulos
	in SoCG 2008 introduced \emph{polygonal partitions}, which use convex
	polygons. We are the first to obtain convex partitions with optimal
	aspect ratio $O(\depth(\tree))$. Furthermore, we consider rectilinear
	partitions, which retain more of the schematized flavor of standard
	rectangular treemaps. Our rectilinear treemaps have constant aspect
	ratio, independent of $\depth(\tree)$ or the number and weight of
	the nodes. The leaves of $\tree$ are represented by rectangles, L-,
	and S-shapes and internal nodes by orthoconvex polygons. We also
	consider the important special case that $\depth(\tree)=1$, that
	is, single-level treemaps. We prove that it is strongly NP-hard to
	minimize the aspect ratio of a rectangular single-level treemap.
	On the positive side we show how to construct rectilinear and convex
	single-level treemaps with constant aspect ratio. Our rectilinear
	single-level treemaps use only rectangles and L-shapes and have aspect
	ratio at most $2 + 2 \sqrt{3}/3$. The convex version uses four different
	octilinear shapes and has aspect ratio at most 9/2.},
  url = {http://arxiv.org/abs/1012.1749v2}
}

@BOOK{Bertin1984,
  title = {Semiology of graphics: Diagrams, networks, maps},
  publisher = {University of Wisconsin Press},
  year = {1984},
  author = {Jacques Bertin},
  isbn = {0299090604},
  abstract = {Originally published in French in 1967, Semiology of Graphics is internationally
	recognized as a foundational work in the fields of design and cartography.
	Based on Jacques Bertin's practical experience as a cartographer,
	part one of this work is an unprecedented attempt to synthesize principles
	of graphic communication with the logic of standard rules applied
	to writing and topography. Part two brings Bertin's theory to life,
	presenting a close study of graphic techniques, including shape,
	orientation, color, texture, volume, and size, in an array of more
	than 1,000 maps and diagrams. Now, with a new epilogue written by
	the author shortly before his death, this new 2010 edition in English
	reawakens us to the information design possibilities of modern technology.
	Jacques Bertin was a French cartographer and theorist, and a world
	renowned authority on the subject of information visualization. In
	1954, he founded the Cartographic Laboratory of the Ecole Pratique
	des Hautes Etudes, and in 1957 he was named director of education.
	In 1967, Bertin became a professor at the Sorbonne, and in 1974 he
	was appointed director of education and director of the Geographical
	Laboratory of the Ecole des Hautes Etudes en Sciences Sociales. In
	the late 1970s, he became head of research at the Centre National
	de la Recherche Scientifique.}
}

@BOOK{Bertin1981,
  title = {Graphics and Graphic Information Processing},
  publisher = {Walter de Gruyter},
  year = {1981},
  author = {Jacques Bertin},
  isbn = {3110088681},
  doi = {10.1515/9783110854688}
}

@BOOK{Bertin1967,
  title = {Semiologie graphique. Les diagrammes, les reseaux, les cartes},
  publisher = {Editions Gauthier-Villars},
  year = {1967},
  author = {Jacques Bertin},
  abstract = {Jacques Bertin a joue un role majeur dans l'evolution des conceptions
	graphiques et cartographiques. Semiologie graphique est l'un de ses
	ouvrages incontournables, plusieurs fois reedite et traduit en anglais.
	Cette nouvelle edition propose une carte hors texte offrant une vision
	saisissante du relief de la France. Elle comporte egalement des mises
	au point originales de Jacques Bertin et constitue une synthese de
	ses demarches. Semiologie graphique apporte une reponse objective
	aux deux questions suivantes: dans quel cas faut-il faire un dessin?
	Quel dessin faut-il faire? La semiologie graphique remplace l'inventaire
	classique des formules graphiques par une analyse des moyens et des
	buts et par un ensemble de regles imperatives qui commandent la redaction
	graphique, c'est-a-dire le choix des correspondances entre les sensibilites
	visuelles disponibles et les elements de l'information.}
}

@ARTICLE{Bhattacharya1994,
  author = {Sourav Bhattacharya and Wei-Tek Tsai},
  title = {Recursive binary tree layout mixing},
  journal = {Information Sciences},
  year = {1994},
  volume = {77},
  pages = {39--49},
  number = {1-2},
  month = {March},
  abstract = {Binary tree layout with adequate boundary-I/O has been approached
	by mixing the H-layout and standard layout patterns. This paper proposes
	a recursive method of mixing these two tree layout patterns. Unlike
	the existing technique (of using a single continuous stretch of H-layout
	and then standard layout for the remaining tree levels), we propose
	to mix these two layout styles in a finer grain. The finer grain
	mixed pattern is then repeated to obtain an overall tree layout.
	This approach offers an order of area improvement over the existing
	single stretch layout mixing approaches, while retaining identical
	boundary-I/O. This makes the proposed approach an order of magnitude
	superior to the existing techniques.},
  doi = {10.1016/0020-0255(94)90047-7}
}

@ARTICLE{Blanch2007,
  author = {Renaud Blanch and \'Eric Lecolinet},
  title = {Browsing {Zoomable Treemaps}: Structure-Aware Multi-Scale Navigation
	Techniques},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2007},
  volume = {13},
  pages = {1248--1253},
  number = {6},
  month = {November},
  abstract = {Treemaps provide an interesting solution for representing hierarchical
	data. However, most studies have mainly focused on layout algorithms
	and paid limited attention to the interaction with treemaps. This
	makes it difficult to explore large data sets and to get access to
	details, especially to those related to the leaves of the trees.
	We propose the notion of zoomable treemaps (ZTMs), an hybridization
	between treemaps and zoomable user interfaces that facilitates the
	navigation in large hierarchical data sets. By providing a consistent
	set of interaction techniques, ZTMs make it possible for users to
	browse through very large data sets (e.g., 700,000 nodes dispatched
	amongst 13 levels). These techniques use the structure of the displayed
	data to guide the interaction and provide a way to improve interactive
	navigation in treemaps.},
  doi = {10.1109/TVCG.2007.70540}
}

@MISC{Bowers1996,
  author = {Frank H. Bowers and Stuart K. Card},
  title = {Method and apparatus for visualization of database search results},
  howpublished = {United States Patent US 5546529, filed Jul. 28, 1994, issued Aug.
	13},
  year = {1996},
  abstract = {A method and apparatus for representing the results of a search of
	a database. The present invention provides for creating a view of
	database search results via a tree structure in which detail is selected
	and context preserved. In the present invention, the tree structure
	is created based on user specified parameters. These parameters represent
	attributes of documents stored in the database and may differ from
	the search parameters. The tree structure is then mapped to a static
	reference surface which is visually perceived as three-dimensional.
	The reference surface is comprised of a detail area where detail
	of the tree structure is displayed and a context area for displaying
	other portions of the tree in less detail but which conveys to the
	viewer a sense of context. The tree structure may be scrolled about
	the reference surface to bring portions of the structure into a direct
	detail view while retaining a context view of the overall tree.},
  url = {http://www.freepatentsonline.com/5546529.html}
}

@ARTICLE{BruggemannKlein1989,
  author = {Anne Br\"uggemann-Klein and Derick Wood},
  title = {Drawing trees nicely with {\TeX}},
  journal = {Electronic Publishing},
  year = {1989},
  volume = {2},
  pages = {101--115},
  number = {2},
  abstract = {Various algorithms have been proposed for the difficult problem of
	producing aesthetically pleasing drawings of trees, see Reingold
	and Tilford (1981), Wetherell and Shannon (1979) but implementations
	only exist as ``special purpose software'', designed for special
	environments. Therefore, many users resort to the drawing facilites
	available on most personal computers, but the figures obtained in
	this way still look ``hand-drawn''; their quality is inferior to
	the quality of the surrounding text that can be realized by today''s
	high quality text processing systems. In this paper we present an
	entirely new solution that integrates a tree drawing algorithm into
	one of the best text processing systems available. More precisely,
	we present a TeX macro package TreeTeX that produces a drawing of
	a tree from a purely logical description. Our approach has three
	advantages. First, labels for nodes can be handled in a reasonable
	way. On the one hand, the tree drawing algorithm can compute the
	widths of the labels and take them into account for the positioning
	of the nodes; on the other hand, all the textual parts of the document
	can be treated uniformly. Second, TreeTeX can be trivially ported
	to any site running TeX. Finally, modularity in the description of
	a tree and TeX's macro capabilities allow for libraries of subtrees
	and tree classes. In addition, we have implemented an option that
	produces drawing which make the structure of the trees more obvious
	to the human eye, even though they may not be as aesthetically pleasing.},
  url = {http://cajun.cs.nott.ac.uk/compsci/epo/papers/volume2/issue2/epabk022.pdf}
}

@BOOK{Brinton1939,
  title = {Graphic Presentation},
  publisher = {Brinton Associates},
  year = {1939},
  author = {Willard Cope Brinton},
  abstract = {Graphic Presentation is largely a collection of interesting charts
	and pictures, mostly of a non-technical nature,covering a wide range
	of subject matter, with brief comment on methodology under each illustration.
	These charts and pictures are reproductions from numerous sources,
	including a few from his Graphic Methods. In addition to the chapters
	on types of charts and excerpts from Time Series Charts: A Manual
	of Design and Construction published by the American Society of Mechanical
	Engineers, there are some quasi-technical chapters on such things
	as the use of cameras and lantern slides, selection of paper, and
	methods of reproduction, printing, and binding. A chapter on tabulation
	is thrown in, apparently for good measure. Illustrations on alternate
	pairs of facing pages arc in color, and these pages contain also
	decorative chapter identification (bleed-outs) at the top and bottom.
	Printing was done by the photo offset process. The verbal language
	is Basic English. A minor feature of the book is a device whereby
	the reader may spin the pages rapidly until he reaches the desired
	chapter. On page 453 is given a detailed description of how the book
	was made up, including the names and addresses of the companies furnishing
	materials or services. This book departs from the earlier contribution
	in several respects. Text material is boiled down almost to the vanishing
	point, leaving the maximum number of charts to speak for themselves.},
  url = {http://www.archive.org/details/graphicpresentat00brinrich}
}

@ARTICLE{Buchin2011a,
  author = {Kevin Buchin and David Eppstein and Maarten L\"offler and Martin
	N\"ollenburg and Rodrigo I. Silveira},
  title = {Adjacency-Preserving Spatial {Treemaps}},
  journal = {arXiv.org e-print service},
  year = {2011},
  volume = {1105.0398v1},
  abstract = {Rectangular layouts, subdivisions of an outer rectangle into smaller
	rectangles, have many applications in visualizing spatial information,
	for instance in rectangular cartograms in which the rectangles represent
	geographic or political regions. A spatial treemap is a rectangular
	layout with a hierarchical structure: the outer rectangle is subdivided
	into rectangles that are in turn subdivided into smaller rectangles.
	We describe algorithms for transforming a rectangular layout that
	does not have this hierarchical structure, together with a clustering
	of the rectangles of the layout, into a spatial treemap that respects
	the clustering and also respects to the extent possible the adjacencies
	of the input layout.},
  url = {http://arxiv.org/abs/1105.0398}
}

@ARTICLE{Buchin2011c,
  author = {Kevin Buchin and Bettina Speckmann and Kevin Verbeek},
  title = {{Flow Map} Layout via {Spiral Trees}},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2011},
  volume = {17},
  pages = {2536--2544},
  number = {12},
  note = {to appear},
  abstract = {Flow maps are thematic maps that visualize the movement of objects,
	such as people or goods, between geographic regions. One or more
	sources are connected to several targets by lines whose thickness
	corresponds to the amount of flow between a source and a target.
	Good flow maps reduce visual clutter by merging (bundling) lines
	smoothly and by avoiding self-intersections. Most flow maps are still
	drawn by hand and only few automated methods exist. Some of the known
	algorithms do not support edge-bundling and those that do, cannot
	guarantee crossing-free flows. We present a new algorithmic method
	that uses edge-bundling and computes crossing-free flows of high
	visual quality. Our method is based on so-called spiral trees, a
	novel type of Steiner tree which uses logarithmic spirals. Spiral
	trees naturally induce a clustering on the targets and smoothly bundle
	lines. Our flows can also avoid obstacles, such as map features,
	region outlines, or even the targets. We validate our approach with
	extensive experiments.},
  doi = {10.1109/TVCG.2011.202}
}

@ARTICLE{Buchin2011d,
  author = {Kevin Buchin and Bettina Speckmann and Kevin Verbeek},
  title = {Angle-Restricted {Steiner} Arborescences for {Flow Map} Layout},
  journal = {arXiv.org e-print service},
  year = {2011},
  volume = {1109.3316},
  abstract = {We introduce a new variant of the geometric Steiner arborescence problem,
	motivated by the layout of flow maps. Flow maps show the movement
	of objects between places. They reduce visual clutter by bundling
	lines smoothly and avoiding self-intersections. To capture these
	properties, our angle-restricted Steiner arborescences, or flux trees,
	connect several targets to a source with a tree of minimal length
	whose arcs obey a certain restriction on the angle they form with
	the source. We study the properties of optimal flux trees and show
	that they are planar and consist of logarithmic spirals and straight
	lines. Flux trees have the shallow-light property. We show that computing
	optimal flux trees is NP-hard. Hence we consider a variant of flux
	trees which uses only logarithmic spirals. Spiral trees approximate
	flux trees within a factor depending on the angle restriction. Computing
	optimal spiral trees remains NP-hard, but we present an efficient
	2-approximation, which can be extended to avoid ``positive monotone''
	obstacles.},
  url = {http://arxiv.org/abs/1109.3316}
}

@INPROCEEDINGS{Burch2011,
  author = {Michael Burch and Daniel Weiskopf},
  title = {Visualizing Dynamic Quantitative Data in Hierarchies. {TimeEdgeTrees}:
	Attaching Dynamic Weights to Tree Edges},
  booktitle = {IVAPP'11: Proceedings of International Conference on Visualization
	Theory and Applications},
  year = {2011},
  pages = {177--186},
  abstract = {In this paper we introduce a technique for visualizing the dynamics
	of quantitative data in static hierarchical structures. We exploit
	the straight links of orthogonal tree diagrams as a timeline on which
	we visually encode dynamic quantitative information. We use color
	coding and varying thicknesses to represent the time-varying data.
	Bimodal data can also be displayed by exploiting both sides of the
	time axes simultaneously. Our TimeEdgeTrees tool allows us to explore
	dynamic quantitative data in tree diagrams by interactive data filtering
	and zooming. The spatial proximity of neighboring hierarchically
	structured elements allows us to easily explore trends, countertrends,
	periodicity, temporal shifts, or anomalies during the evolution synchronously.
	Interactive features such as expanding or collapsing of subhierarchies
	additionally help to detect the aforementioned phenomena on different
	levels of granularity. The usefulness of our visualization technique
	is illustrated by water level data acquired at more than 450 measurement
	stations along German rivers for 768 points in time.},
  url = {http://www.vis.uni-stuttgart.de/uploads/tx_vispublications/Burch2011.pdf}
}

@MISC{Cao2011,
  author = {Nan Cao and Shixia Liu and Hao Lu and Xi Jun Ma and Martin M. Wattenberg},
  title = {Method and apparatus for improving the visibility of a {Treemap}},
  howpublished = {United States Patent US 7870509 B2, filed Apr. 26, 2007, issued Jan.
	11},
  year = {2011},
  abstract = {The visibility of a treemap is improved by offsetting the area of
	a parent node relative to a bounding box containing all of its child
	nodes while constructing the treemap, so that a part of the bounding
	box lies outside the area of the parent node, and the area of each
	child node in the bounding box is located entirely or partially within
	the area of the parent node. The present invention highlights the
	parent-child relationships in the treemap with a cascading effect
	to make the structural information therein more apparent and easier
	to recognize.},
  url = {http://www.freepatentsonline.com/7870509.html}
}

@MISC{Cao2008,
  author = {Nan Cao and Shi Xia Liu and Hui Su},
  title = {Method and apparatus for generating {3D Carousel Tree} data visualization
	and related device},
  howpublished = {United States Patent Application US 2008/0295037 A1, filed Apr. 25,
	2008, published Nov. 27},
  year = {2008},
  abstract = {A method for generating 3D carousel visualization of large-scale tree
	data, which comprises the steps of: receiving a user's selection
	of a node in the carousel; according to the radius of a sub-carousel
	corresponding to the user-selected node and the radius of a carousel
	at which the selected node is located, judging whether or not the
	sub-carousel can be expanded at the carousel at which the selected
	node is located; expanding the sub-carousel at the carousel at which
	the selected node is located, if it is determined that the sub-carousel
	can be expanded at the carousel at which the selected node is located.
	A device capable of implementing the method is provided. The number
	of carousel levels visualized on a visualization device can be adjusted
	dynamically, and the visualization of a focus becomes more prominent,
	and relationships between nodes at each level of the tree data visualization
	get more apparent.},
  url = {http://www.freepatentsonline.com/y2008/0295037.html}
}

@MISC{Card2005,
  author = {Stuart K. Card and David A. Nation},
  title = {System and method for browsing hierarchically based node-link structures
	based on an estimated degree of interest},
  howpublished = {United States Patent US 6944830 B2, filed Dec. 21, 2000, issued Sep.
	13},
  year = {2005},
  abstract = {Method and system to enable a user to view large collections of hierarchically
	linked information on a computer based display. A tree structure
	visualization is created which presents a representation of the complete
	collection of information on the display. The visualization fits
	completely within a fixed area of the computer based display, negating
	the need to scroll information into the display area. The visualization
	is based on identified focus nodes and through calculation of a Degree
	of Interest (DOI) for each of the nodes based in the structure. Layout
	and presentation of the visualization structure is based on the DOI
	values in combination with considerations of available display space.
	A user may dynamically manipulate views of the structure by selecting
	one or more focus nodes, thus causing a recalculation of the degree
	of interest.},
  url = {http://www.freepatentsonline.com/6944830.html}
}

@INPROCEEDINGS{Cava2002,
  author = {Ricardo A. Cava and Paulo R. G. Luzzardi and Carla M. D. S. Freitas},
  title = {The Bifocal Tree: A Technique for the Visualization of Hierarchical
	Information Structures},
  booktitle = {IHC'02: } # PROC # {Workshop on Human factors in Computer Systems},
  year = {2002},
  abstract = {This paper reports a new technique for visualizing hierarchies which
	is based on the focus+context concept, but uses two foci instead
	of one. The technique allows improving the presentation of details
	related to some item in the information space as well as the context.
	This is achieved by displaying the hierarchy as a node-edge diagram
	separated in two connected sub-diagrams. One corresponds to the subtree
	with the node of interest as root. The other one represents the context
	and contains the selected node parent and remaining subtrees. Interaction
	issues regarding browsing and other operations are also discussed.},
  url = {http://www.irit.fr/~Marco.Winckler/projects/spider/publications/IHC2002-CavaEtAl.pdf}
}

@MASTERSTHESIS{Chauhan2010,
  author = {Janki Chauhan},
  title = {Analysis and extension of tree visualization},
  school = {University of Texas, Dallas},
  year = {2010},
  month = {December},
  abstract = {Information visualization has always attracted human eye, as visual
	representation and interaction techniques allows one's mind to explore
	and understand large amount of information at a glance. Various information
	visualization techniques have been developed to show results in novel
	forms like graph drawing, hyperbolic tree, tree mapping and many
	more. Some recent development in visualization techniques has been
	done using fractal grammar and adoption for some existing aesthetic
	forms. This thesis presents how the existing algorithm of tree-mapping
	can be made more interactive and informative for end users. By adding
	level based information display, displaying communities in tree and
	treemap and animating the tree drawing adds more readability and
	reduces ambiguity of treemap. We will also discuss, what are various
	ways for data to be extracted and how new information can be derived
	from a given data set.},
  url = {http://proquest.umi.com/pqdweb?did=2262985971&Fmt=2&RQT=309}
}

@ARTICLE{Chen2010,
  author = {Xiaowu Chen and Haolin Yang and Yongtao Ma and Bin Zhou},
  title = {A Magic Treemap Cube for Visualizing Olympic Games Data},
  journal = {The International Journal of Virtual Reality},
  year = {2010},
  volume = {9},
  pages = {9--17},
  number = {3},
  month = {September},
  abstract = {Treemap, a common information visualization approach for dividing
	a display area into nested rectangles, has a good performance on
	visualizing hierarchical data. And it enables user to compare nodes
	in the same level and to learn certain relationship between adjacent
	levels. However, treemap layout is limited to visualize multi-dimensional
	hierarchical data in which the hierarchy is unfixed and complex,
	especially when the hierarchy is an arbitrary graph. Considering
	this problem, we present a novel extension called magic treemap cube,
	which improves the layout and has a good performance on visualizing
	unfixed (cross-level) and complex data, inverting hierarchy without
	reorganizing the structure, and enabling users to easily compare
	among treemaps. The magic treemap cube is a three-dimensional regular
	hexahedron whose six faces are covered by six different treemaps.
	Each dimension of the magic treemap cube is a hierarchy structure
	specified by users according to a hierarchical division of visualization
	information. With the treemap algorithm, tagcloud and mapping rules,
	the treemaps are automatically controlled by permutations of three
	dimensions of the cube. Users could observe the six correlative treemaps
	respectively by rotating the magic treemap cube in three dimensional
	Cartesian coordinate. And this magic treemap cube can be unfolded
	into a tiled treemap in 2D Cartesian coordinate for users-friendly
	comparison of each treemap. Meanwhile, a merging operation to the
	tiled treemap is proposed to not only compare two treemaps through
	the adjacency relations among faces but also provide more information.
	For demonstrating the above characteristics, an application (called
	OlympicVis) has been implemented to visualize the Beijing 2008 Olympic
	Games information, which involves multi-dimensional hierarchy and
	interconnected data. The OlympicVis can display Cube View, Schedule
	View, Medal View, Date Filter and Time Line.},
  url = {http://www.ijvr.org/issues/issue3-2010/paper2.pdf}
}

@ARTICLE{Collins2009,
  author = {Christopher Collins and Sheelagh Carpendale and Gerald Penn},
  title = {{DocuBurst}: Visualizing Document Content using Language Structure},
  journal = {Computer Graphics Forum},
  year = {2009},
  volume = {28},
  pages = {1039-1046},
  number = {3},
  month = {June},
  abstract = {Textual data is at the forefront of information management problems
	today. One response has been the development of visualizations of
	text data. These visualizations, commonly based on simple attributes
	such as relative word frequency, have become increasingly popular
	tools. We extend this direction, presenting the first visualization
	of document content which combines word frequency with the human-created
	structure in lexical databases to create a visualization that also
	reflects semantic content. DocuBurst is a radial, space-filling layout
	of hyponymy (the IS-A relation), overlaid with occurrence counts
	of words in a document of interest to provide visual summaries at
	varying levels of granularity. Interactive document analysis is supported
	with geometric and semantic zoom, selectable focus on individual
	words, and linked access to source text.},
  doi = {10.1111/j.1467-8659.2009.01439.x}
}

@ARTICLE{Ducheyne2009,
  author = {Steffen Ducheyne},
  title = {To treat of the world -- {Paul Otlet}'s ontology and epistemology
	and the circle of knowledge},
  journal = {Journal of Documentation},
  year = {2009},
  volume = {65},
  pages = {223-244},
  number = {2},
  abstract = {The purpose of this paper is to document how Paul Otlet, founding-father
	of what is termed at present as information science, attempted to
	provide a complete image of the world (and reality in general) by
	establishing the scientific discipline he dubbed documentation. The
	paper also aims to focus on how Otlet represented human knowledge
	and reality in a systematic and unified way. Most importantly, it
	is shown that Otlet's views on documentation were immersed in a cosmological,
	objectivist, humanitarian and ontological framework that is alien
	to contemporary information science. Correspondingly, his alleged
	affinity with positivism is reassessed.},
  doi = {10.1108/00220410910937598}
}

@ARTICLE{Eades1992,
  author = {Peter Eades},
  title = {Drawing free trees},
  journal = {Bulletin of the Institute of Combinatorics and its Applications},
  year = {1992},
  volume = {5},
  pages = {10--36},
  abstract = {Trees are models of various structures in computing and it is not
	surprising that considerable efforts have been made towards effective
	drawing algorithms for them. This paper discusses drawing algorithms
	for "free trees", that is, trees with no special root. The aim of
	these algorithms is to provide a drawing which satisfies several
	aesthetic criteria, such as avoiding edge crossings, minimizing variance
	in edge length, and keeping vertices a resonable distance apart.
	In this paper we measure the effectiveness of the algorithm presented
	by proving or disproving that they achieve such criteria.}
}

@ARTICLE{Eades1993,
  author = {Peter Eades and Tao Lin and Xuemin Lin},
  title = {Two Tree Drawing Conventions},
  journal = {International Journal of Computational Geometry and Applications},
  year = {1993},
  volume = {3},
  pages = {133--153},
  number = {2},
  abstract = {Rooted trees abound in computing and it is often necessary to draw
	them for visualization and documentation purposes. In the classical
	convention for tree drawing, the tree is drawn in a "level" fashion,
	with nodes (represented by boxes) at depth k lying on a horizontal
	line at a distance of k units below the root. The parent-child relationships
	are represented by lines between the boxes. Several algorithms have
	been developed for constructing a compact layout of a tree in the
	classical convention. In this paper we investigate algorithms for
	drawing trees according to two new conventions. In the inclusion
	convention, nodes are represented by boxes, and the parent-child
	relationship is represented by inclusion of one box in another. The
	tip-over convention again represents nodes as boxes, and, like the
	classical convention, represents the parent-child relationship by
	lines between the boxes; however, we allow siblings to be arranged
	vertically rather than horizontally. For many of the cases which
	arise in visualization of trees (for example, binary trees with textual
	information at the leaves) we present polynomial time algorithms.
	However, the general problem of finding minimum size layouts for
	either of the new conventions is shown to be NP-hard.},
  doi = {10.1142/S0218195993000099}
}

@MISC{Eichhorn2006,
  author = {Elisabeth Eichhorn},
  title = {Family tree visualization},
  howpublished = {University project ``Information architecture and -visualisation'',
	\url{http://www.elisabetheichhorn.de/_en/projekte/weiter/stammbaum/stammbaum.html}},
  year = {2006},
  note = {retrieved 26-APR-2010}
}

@ARTICLE{Engel2011,
  author = {Daniel Engel and Rene Rosenbaum and Bernd Hamann and Hans Hagen},
  title = {Structural Decomposition Trees},
  journal = {Computer Graphics Forum},
  year = {2011},
  volume = {30},
  pages = {921--930},
  number = {3},
  month = {June},
  abstract = {Researchers and analysts in modern industrial and academic environments
	are faced with a daunting amount of multi-dimensional data. While
	there has been significant development in the areas of data mining
	and knowledge discovery, there is still the need for improved visualizations
	and generic solutions. The state-of-the-art in visual analytics and
	exploratory data visualization is to incorporate more profound analysis
	methods while focusing on fast interactive abilities. The common
	trend in these scenarios is to either visualize an abstraction of
	the data set or to better utilize screen-space. This paper presents
	a novel technique that combines clustering, dimension reduction and
	multi-dimensional data representation to form a multivariate data
	visualization that incorporates both detail and overview. This amalgamation
	counters the individual drawbacks of common projection and multi-dimensional
	data visualization techniques, namely ambiguity and clutter. A specific
	clustering criterion is used to decompose a multi-dimensional data
	set into a hierarchical tree structure. This decomposition is embedded
	in a novel Dimensional Anchor visualization through the use of a
	weighted linear dimension reduction technique. The resulting Structural
	Decomposition Tree (SDT) provides not only an insight of the data
	set's inherent structure, but also conveys detailed coordinate value
	information. Further, fast and intuitive interaction techniques are
	explored in order to guide the user in highlighting, brushing, and
	filtering of the data.},
  doi = {10.1111/j.1467-8659.2011.01941.x}
}

@MISC{Eppstein2009,
  author = {David Eppstein},
  title = {Visualizing {BFS} as a spiral},
  howpublished = {\url{http://11011110.livejournal.com/171440.html}},
  month = {May},
  year = {2009},
  note = {retrieved 26-APR-2010}
}

@MISC{Etemad2010,
  author = {Katayoon Etemad and Sheelagh Carpendale},
  title = {Symmetry and Node Focused Visualization of Large Trees},
  howpublished = {poster presentation at the GRAND NCE Annual Conference},
  month = {June},
  year = {2010},
  abstract = {In this paper, we take a different approach to visualizing very large
	trees. To facilitate presentation and exploration of massive hierarchical
	datasets such as linguistic and genealogical hierarchies, our approach
	considers drawing layouts of tree-cuts as a function of a node-of-interest
	or NOI, and uses interaction to support rapid access to the entire
	tree. Instead of emphasizing overall tree structure, our layout is
	designed to make the most space available for the node-of-interest
	and its immediate ancestors and descendants. Inspired from Persian
	floral patterns, we describe the development of ShamsehTree and PaisleyTree,
	showing how the use of symmetry can provide new structures for tree
	layouts.}
}

@MISC{Ganascia2012,
  author = {Jean-Gabriel Ganascia},
  title = {Memory Islands -- Ontology display},
  howpublished = {\url{http://www-poleia.lip6.fr/~polyle/NewEX/v11012012/result.html}},
  year = {2012},
  note = {retrieved 26-JAN-2012},
  abstract = {With the concept of Memory Islands, the ACASA team propose a new tree
	visualization approach that is based on cartography, i.e. on a spatialization
	of abstract data structures, mainly trees. The hypothesis on which
	the notion Memory Island is based is that the spatialization helps
	to memorize contents. This notion of Memory Island is applied to
	ontology visualization, which could help to access to many online
	documents.}
}

@BOOK{Gannett1903,
  title = {Twelfth census of the United States, taken in the year 1900. Statistical
	atlas},
  publisher = {U.S. Census Office Washington},
  year = {1903},
  author = {Henry Gannett}
}

@ARTICLE{Hadlak2010,
  author = {Steffen Hadlak and Christian Tominski and Hans-J\"org Schulz and
	Heidrun Schumann},
  title = {Visualization of attributed hierarchical structures in a spatiotemporal
	context},
  journal = {International Journal of Geographical Information Science},
  year = {2010},
  volume = {24},
  pages = {1497--1513},
  number = {10},
  abstract = {When visualizing data, spatial and temporal references of these data
	often have to be considered in addition to the actual data attributes.
	Nowadays, structural information is becoming more and more important.
	Hierarchies, for instance, are frequently applied to make large and
	complex data manageable. Hence, a visual depiction of hierarchical
	structures in space and time is required. While there are several
	techniques addressing specific aspects of spatiotemporal visualization,
	approaches that cope with space, time, data, and structure are rare.
	With this paper we take a step to fill this gap. By combining various
	well-established concepts we achieve a reasonably complete visualization
	of all of the aforementioned aspects, where our focus is on hierarchical
	structures. We embed hierarchies directly into regions of a map display
	using variants of the point-based layout. Layering and animation
	are applied to visualize temporal aspects. Depending on analysis
	goals, users can switch between representations that emphasize data
	attributes or hierarchical structures. Interaction techniques support
	users in navigating the data and their visualization. We demonstrate
	the usefulness of our approach by adapting it to implement a visualization
	for spatio-temporal human health data.},
  doi = {10.1080/13658816.2010.510840}
}

@MISC{Halachmi2000,
  author = {Avi Halachmi and Michael Jacovi and Menachem Shtalhaim and Sigalit
	Ur and Yoelle Maarek},
  title = {Large tree structure visualization and display system},
  howpublished = {United States Patent US 6104400, filed Jul. 28, 1998, issued Aug.
	15},
  year = {2000},
  abstract = {System for the visualization of a large tree structure in which the
	selection of a center object (40) amongst the objects of the large
	tree structure enables n levels of descendants from the center object
	to be visualized on a screen together with the center object, the
	system has a visualization control in computer memory enabling the
	objects of a given level corresponding to the children of a parent
	object of the immediate higher level to be visualized in a fan-shaped
	area centered around the parent object. A scrollbar associated with
	the parent object enables all the children of a parent object to
	be scrolled in a fan. Fan control buttons on the screen enable the
	aperture of the fans to be modified so that a variable number of
	children can be visualized in each fan.},
  url = {http://www.freepatentsonline.com/6104400.html}
}

@ARTICLE{Hao2010,
  author = {Jie Hao and Chad Allen Gabrysch and Chunying Zhao and Qiaoming Zhu
	and Kang Zhang},
  title = {Visualizing and Navigating Hierarchical Information on Mobile User
	Interfaces},
  journal = {International Journal of Advanced Intelligence},
  year = {2010},
  volume = {1},
  pages = {81--103},
  number = {1},
  month = {July},
  abstract = {This paper presents a visualization approach called Radial Edgeless
	Tree (RELT) for visualizing and navigating hierarchical information
	on small screens. Major advantages of the RELT approach include:
	elegance recursive division of the display area, space-filling, maximum
	usage of screen estate, and clarity of the hierarchical structure.
	It offers the flexibility such that users can customize the hierarchy's
	root location and stylize the layout. The RELT drawing algorithm
	is adaptable and customizable for different application domains.
	We have implemented the RELT interface on the Google Android emulator.
	The paper presents the Android implementation, and then provides
	an analytical and empirical comparison of the Android implementation
	with a traditional cell phone interface in terms of their performances
	in navigating hierarchical information.},
  url = {http://aia-i.com/ijai/sample/vol2/no1/81-103.pdf}
}

@ARTICLE{Harel2002,
  author = {David Harel and Gregory Yashchin},
  title = {An algorithm for blob hierarchy layout},
  journal = {The Visual Computer},
  year = {2002},
  volume = {18},
  pages = {164--185},
  number = {3},
  abstract = {We present an algorithm for the aesthetic drawing of basic hierarchical
	blob structures, of the kind found in higraphs and statecharts and
	in other diagrams in which hierarchy is depicted as topological inclusion.
	Our work could also be useful in Web page design, window system dynamics,
	and possibly also newspaper layout, etc. Several criteria for aesthetics
	are formulated, and we discuss their motivation, our methods of implementation
	and the algorithm's performance.},
  doi = {10.1007/s003710100133}
}

@ARTICLE{Hasan2003,
  author = {Masud Hasan and Md. Saidur Rahman and Takao Nishizeki},
  title = {A linear algorithm for compact box-drawings of trees},
  journal = {Networks},
  year = {2003},
  volume = {4},
  pages = {160--164},
  number = {3},
  abstract = {In a box-drawing of a rooted tree, each node is drawn by a rectangular
	box of prescribed size, no two boxes overlap each other, all boxes
	corresponding to siblings of the tree have the same x-coordinate
	at their left sides, and a parent node is drawn at a given distance
	apart from its first child. A box drawing of a tree is compact if
	it attains the minimum possible rectangular area enclosing the drawing.
	We give a linear-time algorithm for finding a compact box-drawing
	of a tree. A known algorithm does not always find a compact box-drawing
	and takes time $O(n^2)$ if a tree has n nodes.},
  doi = {10.1002/net.10092}
}

@INPROCEEDINGS{Hasan2002,
  author = {Masud Hasan and Md. Saidur Rahman and Takao Nishizeki},
  title = {A linear algorithm for compact box-drawings of trees},
  booktitle = {CCCG'02: } # PROC # {Canadian Conference on Computational Geometry},
  year = {2002},
  pages = {154--157},
  abstract = {In a box-drawing of a rooted tree, each node is drawn by a rectangular
	box of prescribed size, no two boxes overlap each other, all boxes
	corresponding to siblings of the tree have the same x-coordinate
	at their left sides, and a parent node is drawn at a given distance
	apart from its first child. A box drawing of a tree is compact if
	it attains the minimum possible rectangular area enclosing the drawing.
	We give a linear-time algorithm for finding a compact box-drawing
	of a tree. A known algorithm does not always find a compact box-drawing
	and takes time $O(n^2)$ if a tree has n nodes.},
  url = {http://www.cccg.ca/proceedings/2002/}
}

@ARTICLE{Heard2009,
  author = {Jeff Heard and William Kaufmann and Xiaojun Guan},
  title = {A novel method for large tree visualization},
  journal = {Bioinformatics},
  year = {2009},
  volume = {25},
  pages = {557--558},
  number = {4},
  abstract = {Many genomic and proteomic analyses generate as a result a tree of
	genes or proteins. These trees are often large (containing tens of
	thousands of nodes and edges), and need a visualization tool to fully
	display all the information contained in the tree. Clustering analysis
	can be performed on these trees to obtain clusters of proteins, and
	we need an efficient way to visualize the clustering results. We
	present a novel tree visualization tool to help with such analyses.},
  doi = {10.1093/bioinformatics/btn656}
}

@MISC{Heer2009,
  author = {Jeffrey M. Heer and Stuart K. Card},
  title = {Method, apparatus, and program product for visualizing tree structured
	information},
  howpublished = {United States Patent US 7627599 B2, filed Apr. 10, 2006, issued Dec.
	1},
  year = {2009},
  abstract = {Apparatus, methods, and computer program products are disclosed that
	perform computationally efficient layout of hierarchical data structures.},
  url = {http://www.freepatentsonline.com/7627599.html}
}

@ARTICLE{Heine2011,
  author = {Christian Heine and Dominic Schneider and Hamish Carr and Gerik Scheuermann},
  title = {Drawing Contour Trees in the Plane},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2011},
  volume = {17},
  pages = {1599--1611},
  number = {11},
  month = {November},
  abstract = {The contour tree compactly describes scalar field topology. From the
	viewpoint of graph drawing, it is a tree with attributes at vertices
	and optionally on edges. Standard tree drawing algorithms emphasize
	structural properties of the tree and neglect the attributes. Applying
	known techniques to convey this information proves hard and sometimes
	even impossible. We present several adaptions of popular graph drawing
	approaches to the problem of contour tree drawing and evaluate them.
	We identify five aesthetic criteria for drawing contour trees and
	present a novel algorithm for drawing contour trees in the plane
	that satisfies four of these criteria. Our implementation is fast
	and effective for contour tree sizes usually used in interactive
	systems (around 100 branches) and also produces readable pictures
	for larger trees, as is shown for a $\sim 800$ branch example.},
  doi = {10.1109/TVCG.2010.270}
}

@ARTICLE{Herman2000,
  author = {Ivan Herman and Guy Melan\c{c}on and M. Scott Marshall},
  title = {Graph Visualization and Navigation in Information Visualization:
	A Survey},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2000},
  volume = {6},
  pages = {24--43},
  number = {1},
  month = {January-March},
  abstract = {This is a survey on graph visualization and navigation techniques,
	as used in information visualization. Graphs appear in numerous applications
	such as Web browsing, state-transition diagrams, and data structures.
	The ability to visualize and to navigate in these potentially large,
	abstract graphs is often a crucial part of an application. Information
	visualization has specific requirements, which means that this survey
	approaches the results of traditional graph drawing from a different
	perspective.},
  doi = {10.1109/2945.841119}
}

@MISC{Hida2005,
  author = {Yozo Hida and John O. Lamping and Ramana B. Rao},
  title = {Tree visualization system and method based upon a compressed half-plane
	model of hyperbolic geometry},
  howpublished = {United States Patent US 6901555 B2, filed July 09, 2001, issued May
	31},
  year = {2005},
  abstract = {A node-link structure is displayed within a display area, having a
	narrow rectangular shape with an edge along one side acting as a
	horizon of a hyperbolic space half-plane. Lower level node features
	that share a parent node feature have centers of area positioned
	on the display in order along a line parallel with the horizon, with
	sufficiently similar spacings along an axis perpendicular to the
	horizon from the region around a parent node feature, and with sufficiently
	similar spacings in a dimension parallel to the horizon from adjacent
	node features along the line, that the lower level node features
	sharing the parent node feature are perceptible as a group of related
	node features. The half-plane model with compression is used for
	layout of the node-link data, and the hyperbolic layout data is mapped
	to a Euclidean space for display.},
  url = {http://www.freepatentsonline.com/6901555.html}
}

@ARTICLE{Hong2008,
  author = {Seok-Hee Hong and Peter Eades},
  title = {Drawing Trees Symmetrically in Three Dimensions},
  journal = {Algorithmica},
  year = {2008},
  volume = {36},
  pages = {153--178},
  number = {2},
  month = {March},
  abstract = {Symmetric graph drawing enables a clear understanding of the structure
	of the graph. Previous work on symmetric graph drawing has focused
	on two dimensions. Symmetry in three dimensions is much richer than
	that of two dimensions. This is the first paper to extend symmetric
	graph drawing into three dimensions. More specifically, the paper
	investigates the problem of drawing trees symmetrically in three
	dimensions. First, we suggest a model for drawing trees symmetrically
	in three dimensions. Based on this model, we present a linear time
	algorithm for finding the maximum number of three-dimensional symmetries
	in trees. We also present a three-dimensional symmetric drawing algorithm
	for trees.},
  doi = {10.1007/s00453-002-1011-4}
}

@INCOLLECTION{Huang2007a,
  author = {Mao Lin Huang and Quang Vinh Nguyen and Wei Lai},
  title = {Creating Visual Browsers for Large-Scale Online Auctions},
  booktitle = {E-Service Intelligence -- Methodologies, Technologies and Applications},
  publisher = {Springer},
  year = {2007},
  editor = {Jie Lu and Da Ruan and Guangquan Zhang},
  pages = {579--600},
  abstract = {This chapter discusses the requirements raised for running online
	auctions as well as the technical issues on the design of graphical
	user interfaces and how we could use these graphical interfaces to
	help users navigate visualization technique called EncCon as well
	as the design of graphic attributes that can be used to present the
	domain specific attributes of the auction items and the relational
	structures among these items, and these graphic presentations will
	provide users with a clear map showing the possible paths to the
	target items. We will demonstrate the effectiveness of our techniques
	by illustrating an online auction prototype that simulates the ordinary
	auction activities with the assistance of visualization.},
  doi = {10.1007/978-3-540-37017-8_27}
}

@TECHREPORT{Itoh2002,
  author = {Takayuki Itoh and Yasumasa Kajinaga and Yuko Ikehata and Yumi Yamaguchi},
  title = {Data Jewelry Box: A Graphics Showcase for Large-Scale Hierarchical
	Data Visualization},
  institution = {IBM Research},
  year = {2002},
  number = {RT0427},
  abstract = {We see many kinds of large-scale hierarchical data in our daily lives,
	such as file systems of computers, company organizations, and category-based
	Web search sites such as Yahoo. Most of the GUIs for these data sources
	first represent a higher level of the data, and provide an interface
	so that users can select an interesting portion of the data and locally
	explore the lower levels. On the other hand, there are not many visualization
	techniques that give an overview of the data by placing all of the
	lower-level data onto a display region. How can we implement such
	a technique that represents all the data in one display, just like
	the showcases of a jewelry store displays all the jewels in the shop?
	That is the motivation of this research.
	
	The report presents a visualization technique that places all of the
	lowest-level portions of a hierarchical data set on a display space.
	It first groups icons that denote the lowest-level data, and then
	generates rectangles that enclose each group of icons. It repeats
	the process of generating rectangles that enclose the lower-level
	rectangles, until the highest-level rectangles are enclosed by the
	largest rectangle. To use the display space most reasonably, our
	technique efficiently searches for gaps where rectangles can be located
	without overlapping adjacent rectangles. We use Delaunay triangular
	meshes that connect the centers of the rectangles to quickly find
	the gaps.},
  url = {http://domino.research.ibm.com/library/cyberdig.nsf/1e4115aea78b6e7c85256b360066f0d4/65ee18867a4cf82385256b870028fa47!OpenDocument}
}

@INPROCEEDINGS{Itoh2003,
  author = {Takayuki Itoh and Koji Koyamada},
  title = {{HeiankyoView}: Orthogonal Representation of Large-scale Hierarchical
	Data},
  booktitle = {PBit'03: } # PROC # {International Symposium Towards Peta-Bit Ultra
	Networks},
  year = {2003},
  pages = {125--130},
  abstract = {Visualization is very useful for various large-scale computing fields.
	One of the authors has reported a hierarchical data visualization
	technique, and applied it to various large-scale computing data including
	large-scale Web sites, but also for data mining results, Web search
	queries, network intrusion detection results, and distributed processes.
	This paper presents the new hierarchical data visualization technique,
	HeiankyoView, which can be also applied to various large-scale computing
	fields. It places data items of input data while it packs the items
	as many as possible in small display areas, and aligns the items
	along X-axis and Y-axis of the display area. The technique represents
	nodes of hierarchical data as a set of rectangles, which are parallel
	to X-axis and Y-axis. Here the technique orthogonally divides the
	display area by extension lines of edges of previously placed rectangles.
	By referring the grid-like subspaces of the display area, the technique
	quickly finds the adequate positions to place remaining rectangles.},
  url = {http://itolab.is.ocha.ac.jp/~itot/paper/ItotRICPE18.pdf}
}

@ARTICLE{Itoh2004,
  author = {Takayuki Itoh and Yumi Yamaguchi and Yuko Ikehata and Yasumasa Kajinaga},
  title = {Hierarchical Data Visualization Using a Fast Rectangle-Packing Algorithm},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2004},
  volume = {10},
  pages = {302--313},
  number = {3},
  month = {May-June},
  abstract = {We present a technique for the representation of large-scale hierarchical
	data which aims to provide good overviews of complete structures
	and the content of the data in one display space. The technique represents
	the data by using nested rectangles. It first packs icons or thumbnails
	of the lowest-level data and then generates rectangular borders that
	enclose the packed data. It repeats the process of generating rectangles
	that enclose the lower-level rectangles until the highest-level rectangles
	are packed. We present two rectangle-packing algorithms for placing
	items of hierarchical data onto display spaces. The algorithms refer
	to Delaunay triangular meshes connecting the centers of rectangles
	to find gaps where rectangles can be placed. The first algorithm
	places rectangles where they do not overlap each other and where
	the extension of the layout area is minimal. The second algorithm
	places rectangles by referring to templates describing the ideal
	positions for nodes of input data. It places rectangles where they
	do not overlap each other and where the combination of the layout
	area and the distances between the positions described in the template
	and the actual positions is minimal. It can smoothly represent time-varying
	data by referring to templates that describe previous layout results.
	It is also suitable for semantics-based or design-based data layout
	by generating templates according to the semantics or design.},
  doi = {10.1109/TVCG.2004.1272729}
}

@ARTICLE{Jia2010a,
  author = {Ming Jia and Suh-Yeon Choi and Dirk Reiners and Eve S. Wurtele and
	Julie A. Dickerson},
  title = {{MetNetGE}: interactive views of biological networks and ontologies},
  journal = {BMC Bioinformatics},
  year = {2010},
  volume = {11},
  number = {469},
  abstract = {Linking high-throughput experimental data with biological networks
	is a key step for understanding complex biological systems. Currently,
	visualization tools for large metabolic networks often result in
	a dense web of connections that is difficult to interpret biologically.
	The MetNetGE application organizes and visualizes biological networks
	in a meaningful way to improve performance and biological interpretability.
	MetNetGE is an interactive visualization tool based on the Google
	Earth platform. MetNetGE features novel visualization techniques
	for pathway and ontology information display. Instead of simply showing
	hundreds of pathways in a complex graph, MetNetGE gives an overview
	of the network using the hierarchical pathway ontology using a novel
	layout, called the Enhanced Radial Space-Filling (ERSF) approach
	that allows the network to be summarized compactly. The non-tree
	edges in the pathway or gene ontology, which represent pathways or
	genes that belong to multiple categories, are linked using orbital
	connections in a third dimension. Biologists can easily identify
	highly activated pathways or gene ontology categories by mapping
	of summary experiment statistics such as coefficient of variation
	and overrepresentation values onto the visualization. After identifying
	such pathways, biologists can focus on the corresponding region to
	explore detailed pathway structure and experimental data in an aligned
	3D tiered layout. In this paper, the use of MetNetGE is illustrated
	with pathway diagrams and data from E. coli and Arabidopsis. MetNetGE
	is a visualization tool that organizes biological networks according
	to a hierarchical ontology structure. The ERSF technique assigns
	attributes in 3D space, such as color, height, and transparency,
	to any ontological structure. For hierarchical data, the novel ERSF
	layout enables the user to identify pathways or categories that are
	differentially regulated in particular experiments. MetNetGE also
	displays complex biological pathway in an aligned 3D tiered layout
	for exploration.},
  doi = {10.1186/1471-2105-11-469}
}

@TECHREPORT{Jia2008,
  author = {Yuntao Jia and John C. Hart},
  title = {Drawing Trees: How Many Circles to Use?},
  institution = {University of Illinois},
  year = {2008},
  abstract = {In this paper, we proposed a new approach for drawing rooted trees
	on circles. Previous approaches either draw entire tree on a single
	circle or draw too many circles that every node and its children
	are on a new circle. As a result, they only work well on limited
	kinds of trees. In contrary, our approach adaptively choose how many
	circles to use based on a single user input and it can be generalized
	well to all kinds of trees. Our approach has three phases. First,
	we recursively divide the tree into a hierarchy of subtrees according
	to the user input. The subtrees are then processed from bottom to
	top of the hierarchy and each of them is drawn around a separated
	circle. Finally, layout of subtrees are assembled together to form
	the layout of the entire tree. Comparing to previous methods, our
	approach obtains both compact and pleasing tree drawings with less
	bends. Furthermore, our method naturally supports visualization interactions,
	such as locally zooming in/out, when user navigates the drawings.
	Several examples are provided to demonstrate the effectiveness of
	our approach.},
  url = {http://hdl.handle.net/2142/14068}
}

@PHDTHESIS{Johnson1993,
  author = {Brian Scott Johnson},
  title = {Treemaps: Visualizing hierarchical and categorical data},
  school = {University of Maryland},
  year = {1993},
  note = {HCIL-94-04, UMI-94-25057},
  abstract = {Treemaps are a graphically based method for the visualization of hierarchical
	or categorical data spaces. Treemap presentations of data shift mental
	workload from the cognitive to the perceptual systems, taking advantage
	of the human visual processing system to increase the bandwidth of
	the human-computer interface. Efficient use of display space allows
	for the simultaneous presentation of thousands of data records, as
	well as facilitating the presentation of semantic information. Treemaps
	let users see the forest and the trees by providing local detail
	in the context of a global overview, providing a visually engaging
	environment in which to analyze, search, explore and manipulate large
	hierarchical and categorical data spaces. The treemap method of hierarchical
	visualization, at its core, is based on the property of containment.
	This property of containment is a fundamental idea which powerfully
	encapsulates many of our reasons for constructing information hierarchies.
	All members of the treemap family of algorithms partition multi-dimensional
	display spaces based on weighted hierarchical data sets. In addition
	to generating treemaps and standard traditional hierarchical diagrams,
	the treemap algorithms extend non-hierarchical techniques such as
	bar and pie charts into the domain of hierarchical presentation.
	Treemap algorithms can be used to generate bar charts, outlines,
	traditional 2-D node and link diagrams, pie charts, cone trees, cam
	trees, drum trees, etc. Generating existing diagrams via treemap
	transformations is an excercise meant to show the power, ease, and
	generality with which alternative presentations can be generated
	from the basic treemap algorithms. Controlled experiments with novice
	treemap users and real data highlight the strengths of treemaps and
	provide direction for improvement. Experimental results show that
	treemaps are a powerful visualization tool for large data sets, significantly
	reducing user performance times for global comparison tasks. Effective
	visualizations of large data sets can help users gain insight into
	relevant features of the data, construct accurate mental models of
	the information, and locate regions of particular interest. Treemaps
	are based on simple, fundamental ideas, but they are the building
	blocks with which an entire world of unique and exciting visualizations
	can be built.}
}

@INPROCEEDINGS{Karstens2003,
  author = {Bernd Karstens and Matthias Kreuseler and Heidrun Schumann},
  title = {Visualization of Complex Structures on Mobile Handhelds},
  booktitle = {IMC'03: } # PROC # {International Workshop Mobile Computing},
  year = {2003},
  abstract = {Information Visualization has become an important research topic in
	Computer Graphics. One key issue of this topic is the visual presentation
	of intrinsic structures of complex information spaces. Today nearly
	all approaches of structure visualization are designed for none-mobile
	devices such as PCs or workstations. However, mobile handhelds have
	become more popular in recent years, and are increasingly used in
	different application domains. Limited resources of these devices
	require new paradigms for information presentation and interaction
	such as new methods for structure visualization based on new metaphors
	for efficient screen space usage. This paper describes how recent
	techniques of structure visualization can be adapted or redesigned
	for mobile pocket-sized devices.},
  url = {http://vcg.informatik.uni-rostock.de/~schumann/papers/2002+/IMC_2003.pdf}
}

@ARTICLE{Kidd2010,
  author = {David M. Kidd},
  title = {Geophylogenies and the Map of Life},
  journal = {Systematic Biology},
  year = {2010},
  volume = {59},
  pages = {741--752},
  number = {6},
  abstract = {One hundred and fifty years after Charles Darwin wrote his ``Origin
	of Species'', two major ongoing Web-based scientific projects are
	collating information on the earth's biological diversity. The Encyclopaedia
	of Life (EoL) provides a single interface through which information
	on each being of the same class can be accessed, whereas The Tree
	of Life (ToL) Web project places these classes onto an evolutionary
	tree. Here, I propose that a third complementary project should now
	be considered, the Map of Life (MoL), in which all we know about
	the biogeographical history of life -- including clades, species,
	their genes, and the communities they are members of -- is threaded
	through a dynamic earth history, capturing the spatiotemporal pathways
	that underlie current and past patterns of biodiversity.},
  doi = {10.1093/sysbio/syq043}
}

@ARTICLE{Kim2007,
  author = {Namshin Kim and Christopher Lee},
  title = {Three-Dimensional Phylogeny Explorer: Distinguishing paralogs, lateral
	transfer, and violation of ''molecular clock´´ assumption with {3D}
	visualization},
  journal = {BMC Bioinformatics},
  year = {2007},
  volume = {8},
  number = {213},
  abstract = {Construction and interpretation of phylogenetic trees has been a major
	research topic for understanding the evolution of genes. Increases
	in sequence data and complexity are creating a need for more powerful
	and insightful tree visualization tools. We have developed 3D Phylogeny
	Explorer (3DPE), a novel phylogeny tree viewer that maps trees onto
	three spatial axes (species on the X-axis; paralogs on Z; evolutionary
	distance on Y), enabling one to distinguish at a glance evolutionary
	features such as speciation; gene duplication and paralog evolution;
	lateral gene transfer; and violation of the "molecular clock" assumption.
	Users can input any tree on the online 3DPE, then rotate, scroll,
	rescale, and explore it interactively as "live" 3D views. All objects
	in 3DPE are clickable to display subtrees, connectivity path highlighting,
	sequence alignments, and gene summary views, and etc. To illustrate
	the value of this visualization approach for microbial genomes, we
	also generated 3D phylogeny analyses for all clusters from the public
	COG database. We constructed tree views using well-established methods
	and graph algorithms. We used Scientific Python to generate VRML2
	3D views viewable in any web browser. 3DPE provides a novel phylogenetic
	tree projection method into 3D space and its web-based implementation
	with live 3D features for reconstruction of phylogenetic trees of
	COG database.},
  doi = {10.1186/1471-2105-8-213}
}

@INCOLLECTION{Kim1996,
  author = {Sung Kwon Kim},
  title = {H-v drawings of binary trees},
  booktitle = {Software Visualization},
  publisher = {World Scientific Publishing},
  year = {1996},
  editor = {Peter Eades and Kang Zhang},
  pages = {101--116},
  abstract = {This chapter considers h-v drawings of binary trees and presents new
	results on it. We prove that binary trees with n nodes can be h-v
	drawn so that the total edge length is O(n log log n), and so that
	the maximum edge length is O(SQRT(n log n).},
  url = {http://ebooks.worldscinet.com/ISBN/9789812797995/9789812797995_0006.html}
}

@ARTICLE{Kleiner1981,
  author = {Beat Kleiner and John A. Hartigan},
  title = {Representing Points in Many Dimensions by Trees and Castles},
  journal = {Journal of the American Statistical Association},
  year = {1981},
  volume = {76},
  pages = {260--269},
  number = {374},
  month = {June},
  abstract = {A number of points in k dimensions are displayed by associating with
	each point a symbol: a drawing of a tree or a castle. All symbols
	have the same structure derived from a hierarchical clustering algorithm
	applied to the k variables (dimensions) over all points, but their
	parts are coded according to the coordinates of each individual point.
	Trees and castles show general size effects, the change of whole
	clusters of variables from point to point, trends, and outliers.
	They are especially appropriate for evaluating the clustering of
	variables and for observing clusters of points. Their major advantage
	over earlier attempts to represent multivariate observations (such
	as profiles, stars, faces, boxes, and Andrews's curves) lies in their
	matching of relationships between variables to relationships between
	features of the representing symbol. Several examples are given,
	including one with 48 variables.},
  doi = {10.2307/2287820}
}

@ARTICLE{Kleiner1981a,
  author = {Beat Kleiner and John A. Hartigan},
  title = {Representing Points in Many Dimensions by Trees and Castles -- Rejoinder},
  journal = {Journal of the American Statistical Association},
  year = {1981},
  volume = {76},
  pages = {276},
  number = {374},
  month = {June},
  doi = {10.2307/2287824}
}

@BOOK{Knuth1968,
  title = {The Art of Computer Programming},
  publisher = {Addison-Wesley},
  year = {1968},
  author = {Donald Knuth},
  volume = {1},
  edition = {1st},
  isbn = {0201038013},
  url = {http://en.wikipedia.org/wiki/The_Art_of_Computer_Programming}
}

@ARTICLE{Koike1995,
  author = {Hideki Koike},
  title = {Fractal views: A fractal-based method for controlling information
	display},
  journal = {ACM Transactions on Information Systems},
  year = {1995},
  volume = {13},
  pages = {305--323},
  number = {3},
  month = {July},
  abstract = {Computer users often must view large amounts of information through
	video displays which are physically limited in size. Although some
	methods, which automatically display/erase information units based
	on their degrees of importance, have been proposed, they lack an
	ability to keep the total amount of displayed information nearly
	constant. We propose a new method for information display based on
	fractal theory. By regarding the information structures used in computers
	as complex objects, we can abstract these objects as well as control
	their amount. Using our method, (1) the total amount of information
	is kept nearly constant even when users change their focuses of attention
	and (2) this amount can be set flexibly. Through mathematical analysis,
	we show our method's ability to control the amount. An application
	to program display is also shown. When this method is applied to
	the display of structured programs, it provides fisheye-like views
	which integrate local details around the focal point and major landmarks
	further away.},
  doi = {10.1145/203052.203065}
}

@ARTICLE{Kruskal1983,
  author = {Joseph B. Kruskal and James M. Landwehr},
  title = {Icicle Plot: Better Displays for Hierarchical Clustering},
  journal = {The American Statistician},
  year = {1983},
  volume = {37},
  pages = {162--168},
  number = {2},
  abstract = {An icicle plot is a method for presenting a hierarchical clustering.
	Compared with other methods of presentation, it is far easier in
	an icicle plot to read off which objects belong to which clusters,
	and which objects join or drop out from a cluster as we move up and
	down the levels of the hierarchy, though these benefits only appear
	when enough objects are being clustered. Icicle plots are described,
	and their benefits are illustrated using a clustering of 48 objects.},
  doi = {10.2307/2685881}
}

@ARTICLE{Lamping1996,
  author = {Jonh Lamping and Ramana Rao},
  title = {The {Hyperbolic Browser}: A Focus+Context Technique for Visualizing
	Large Hierarchies},
  journal = {Journal of Visual Languages and Computing},
  year = {1996},
  volume = {7},
  pages = {33--55},
  number = {1},
  month = {March},
  abstract = {We present a new focus+context technique based on hyperbolic geometry
	for visualizing and manipulating large hierarchies. Our technique
	assigns more display space to a portion of the hierarchy while still
	embedding it in the context of the entire hierarchy. We lay out the
	hierarchy in a uniform way on a hyperbolic plane and map this plane
	onto a display region. The chosen mapping provides a fisheye distortion
	that supports a smooth blending of focus and context. We have deveoped
	effective procedures for manipulating the focus using pointer clicks
	as well as interactive dragging and for smoothly animating transitions
	across such manipulation. Enhancements to the core mechanisms provide
	support for multiple foci, control of the tradeoff between node density
	and node display space, and for visualizing graphs by transforming
	them into trees.},
  doi = {10.1006/jvlc.1996.0003}
}

@MISC{Lamping1997,
  author = {John O. Lamping and Ramana B. Rao},
  title = {Displaying node-link structure with region of greater spacings and
	peripheral branches},
  howpublished = {United States Patent US 5619632, filed Sep. 14, 1994, issued Apr.
	8},
  year = {1997},
  abstract = {Node-link data defining a node-link structure are used to present
	a sequence of representations on a display. The last representation
	in the sequence is perceptible as a changed continuation of the first.
	Each representation includes bounded node features, each with a center
	of area and a nearest node spacing that define a mid-spacing circle.
	All mid-spacing circles together determine an outer convex hull enclosing
	a total area for the representation. The mid-spacing circles of a
	subset of more spaced node features determine an inner convex hull
	enclosing approximately half the total area and enclosing a region
	in which nearest node spacings are in general perceptibly greater
	than in another region outside the second convex hull. The node features
	also represent a peripheral branch with lower level nodes that are
	not represented by more spaced node features. In the peripheral branch,
	node features that share a parent have centers of area positioned
	approximately along an arc with sufficiently similar spacings from
	the center of area of the parent node feature and from adjacent node
	features that they are perceptible as a group of related node features.
	The inner convex hulls of the first and last representations include
	subsets of node features representing different sets of nodes. The
	sequence can produce a perception that one node feature's nearest
	node spacing increases while another's decreases. The representations
	can be presented by a series of iterations, and can be presented
	at animation speeds to produce a perception of continuously moving
	node features.},
  url = {http://www.freepatentsonline.com/5619632.html}
}

@MISC{Lamping1996b,
  author = {John O. Lamping and Ramana B. Rao},
  title = {Layout of node-link structures in space with negative curvature},
  howpublished = {United States Patent US 5590250, filed Sep. 14, 1994, issued Dec.
	31},
  year = {1996},
  abstract = {Layout data indicate positions in a negatively curved layout space
	for nodes in a hierarchical branch of a node-link structure. The
	layout data indicate a parent position for parent nodes and, for
	children that share a parent node, child positions approximately
	along a circle in the layout space with the parent position approximately
	at the circle's center. Adjacent child positions are separated by
	approximately a base spacing. The radii of circles within the branch
	together approximate a function that increases slowly with number
	of child nodes such that the radii and spacings along circles are
	all approximately uniform within the branch. The layout data can
	be obtained from data defining the node-link structure. The layout
	data can be used to perform mappings, each obtaining positions for
	a subset of the nodes. The layout data can be used to present a first
	representation of the node-link structure on a display. In response
	to a user signal indicating a change from a first display position
	near a first feature to a second display position, a second representation
	can be presented that is perceptible as a changed continuation of
	the first. The second representation includes, near the second display
	position, a second feature representing the same part of the node-link
	structure as the first feature. The second representation can be
	obtained by a transformation of the layout space, which can be a
	discrete approximation of a hyperbolic plane.},
  url = {http://www.freepatentsonline.com/5590250.html}
}

@ARTICLE{Larrea2009,
  author = {Martin Larrea and Dana Urribarri and Sergio Martig and Silvia Castro},
  title = {Spherical Layout Implementation using Centroidal Voronoi Tessellations},
  journal = {Journal of Computing},
  year = {2009},
  volume = {1},
  pages = {81--86},
  number = {1},
  month = {Dec},
  abstract = {The 3D tree visualization faces multiple challenges: the election
	of an appropriate layout, the use of the interactions that make the
	data exploration easier and a metaphor that helps in the process
	of information understanding. A good combination of these elements
	will result in a visualization that effectively conveys the key features
	of a complex structure or system to a wide range of users and permits
	the analytical reasoning process. In previous works we presented
	the Spherical Layout, a technique for 3D tree visualization that
	provides an excellent base to achieve those key features. The layout
	was implemented using the TriSphere algorithm, a method that discretized
	the spheres's surfaces with triangles to achieve a uniform distribution
	of the nodes. The goal of this work was centered in a new algorithm
	for the implementation of the Spherical layout; we called it the
	Weighted Spherical Centroidal Voronoi Tessellations (WSCVT). In this
	paper we present a detailed description of this new implementation
	and a comparison with the TriSphere algorithm.},
  url = {http://arxiv.org/abs/0912.3974}
}

@MISC{Leah2008,
  author = {Robert Leah and Kenneth Parzygnat and Robert Uthe},
  title = {Intelligent positioning of items in a tree map visualization},
  howpublished = {United States Patent US 7429987 (B2), filed Sep. 19, 2003, issued
	Sep. 30},
  year = {2008},
  abstract = {Displaying data from a data set in a tree map visualization is provided
	by prioritizing the data in the data set so as to associate a priority
	with respective elements of the data in the data set. A tree map
	visualization is generated based on the data set where a location
	of bounding boxes in the tree map is based on the priority associated
	with the corresponding element. Tree maps having locations of bounding
	boxes that are based on a priority associated with the bounding boxes
	are also provided.},
  url = {http://www.freepatentsonline.com/7429987.html}
}

@MISC{Leclair2010,
  author = {Andrew LeClair},
  title = {Directory Tree, A data visualization mashup},
  howpublished = {Online portfolio, \url{hhttp://www.andrewleclair.com/archive.html}},
  year = {2010},
  note = {retrieved 09-JAN-2012}
}

@ARTICLE{Lee2009,
  author = {Bongshin Lee and Lev Nachmanson and George Robertson and Jonathan
	M. Carlson and David Heckerman},
  title = {{PhyloDet}: A scalable visualization tool for mapping multiple traits
	to large evolutionary trees},
  journal = {Bioinformatics},
  year = {2009},
  volume = {25},
  pages = {2611--2612},
  number = {19},
  abstract = {Evolutionary biologists are often interested in finding correlations
	among biological traits across a number of species, as such correlations
	may lead to testable hypotheses about the underlying function. Because
	some species are more closely related than others, computing and
	visualizing these correlations must be done in the context of the
	evolutionary tree that relates species. In this note, we introduce
	PhyloDet (short for PhyloDetective), an evolutionary tree visualization
	tool that enables biologists to visualize multiple traits mapped
	to the tree.},
  doi = {10.1093/bioinformatics/btp454}
}

@MISC{Lee2009a,
  author = {Bongshin Lee and Lev Nachmanson and George G. Robertson},
  title = {Visualizing tree structure with different edge lengths},
  howpublished = {United States Patent Application US 2009/0198725 A1, filed May 13,
	2008, published Aug. 06},
  year = {2009},
  abstract = {A system described herein includes a receiver component that receives
	multiple data elements, wherein each of the data elements has a common
	attribute, and wherein the several data elements are hierarchically
	related. The system may further include an assignor component that
	independently assigns each of the multiple data elements to one of
	a plurality of layers, wherein a data element is assigned to a layer
	based at least in part upon a value of the common attribute that
	corresponds to the data element. The system may also include a renderer
	component that receives assignments made by the assignor component
	and graphically renders a tree structure based at least in part upon
	the assignments. Furthermore, a color bar can be generated that includes
	one or more rows based at least in part upon content of the tree
	structure.},
  url = {http://www.freepatentsonline.com/y2009/0198725.html}
}

@TECHREPORT{Lee2008,
  author = {Bongshin Lee and Lev Nachmanson and George G. Robertson and Jonathan
	Carlson and David Heckerman},
  title = {Det. ({Distance Encoded Tree}): A Scalable Visualization Tool for
	Mapping Multiple Traits to Large Evolutionary Trees},
  institution = {Microsoft Research},
  year = {2008},
  number = {MSR-TR-2008-97},
  abstract = {Evolutionary biologists are often interested in finding correlations
	among biological traits (or attributes) across a number of species,
	as such correlations may lead to testable hypotheses about the underlying
	function. Because some species are more closely related than others,
	computing and visualizing these correlations must be done in the
	context of the evolutionary tree that relates the species. Although
	dozens of visualizations for correlated traits have been developed
	over the decades, the recent explosive growth in the number of traits
	and species has created a need for a visualization that can scale
	to dozens of traits mapped to thousands of species and their evolutionary
	tree to allow the interactive exploration of complex interactions.
	In this paper, we introduce Det., called detective, an evolutionary
	tree visualization that allows biologists to see multiple attributes
	of leaf nodes. We describe a new tree layout algorithm to represent
	different branch lengths and several visualization and intereaction
	techniques to address user requirements. We also report informal
	feedbacks we collected from evolutionary biologists.},
  url = {http://research.microsoft.com/apps/pubs/default.aspx?id=70606}
}

@ARTICLE{Lin2007,
  author = {Chun-Cheng Lin and Hsu-Chun Yen},
  title = {On Balloon Drawings of Rooted Trees},
  journal = {Journal of Graph Algorithms and Applications},
  year = {2007},
  volume = {11},
  pages = {431--452},
  number = {2},
  abstract = {Among various styles of tree drawing reported in the literature, balloon
	drawing enjoys a desirable feature of displaying tree structures
	in a rather balanced fashion. Each subtree in the balloon drawing
	of a tree is enclosed in a circle. Along any path from the root node,
	the radius of each circle reflects the number of descendants associated
	with the root node of the subtree. In this paper, we investigate
	various issues related to balloon drawings of rooted trees from the
	algorithmic viewpoint. First, we design an efficient algorithm to
	optimize the angular resolution and the aspect ratio for the balloon
	drawings of rooted unordered trees. For the case of ordered trees
	for which the center of the enclosing circle of a subtree need not
	coincide with the root of the subtree, flipping the drawing of a
	subtree (along the axis from the parent to the root of the subtree)
	might change both the aspect ratio and the angular resolution of
	the drawing. We show that optimizing the angular resolution as well
	as the aspect ratio with respect to this type of rooted ordered trees
	is reducible to the perfect matching problem for bipartite graphs,
	which is solvable in polynomial time. In addition, a related problem
	concerning the optimization of the drawing area can be modelled as
	a specific type of nonlinear programming for which there exist several
	robust algorithms in practice. With a slight modification to the
	balloon drawing, we are able to generate the drawings of galaxy systems,
	H-trees, and sparse graphs, which are of practical interest.},
  url = {http://www.emis.de/journals/JGAA/accepted/2007/LinYen2007.11.2.pdf}
}

@ARTICLE{Lin2011,
  author = {Chun-Cheng Lin and Hsu-Chun Yen and Sheung-Hung Poon and Jia-Hao
	Fan},
  title = {Complexity analysis of balloon drawing for rooted trees},
  journal = {Theoretical Computer Science},
  year = {2011},
  volume = {412},
  pages = {430--447},
  number = {4-5},
  abstract = {In a balloon drawing of a tree, all the children under the same parent
	are placed on the circumference of the circle centered at their parent,
	and the radius of the circle centered at each node along any path
	from the root reflects the number of descendants associated with
	the node. Among various styles of tree drawings reported in the literature,
	the balloon drawing enjoys a desirable feature of displaying tree
	structures in a rather balanced fashion. For each internal node in
	a balloon drawing, the ray from the node to each of its children
	divides the wedge accommodating the subtree rooted at the child into
	two sub-wedges. Depending on whether the two sub-wedge angles are
	required to be identical or not, a balloon drawing can further be
	divided into two types: even sub-wedge and uneven sub-wedge types.
	In the most general case, for any internal node in the tree there
	are two dimensions of freedom that affect the quality of a balloon
	drawing: (1) altering the order in which the children of the node
	appear in the drawing, and (2) for the subtree rooted at each child
	of the node, flipping the two sub-wedges of the subtree. In this
	paper, we give a comprehensive complexity analysis for optimizing
	balloon drawings of rooted trees with respect to angular resolution,
	aspect ratio and standard deviation of angles under various drawing
	cases depending on whether the tree is of even or uneven sub-wedge
	type and whether (1) and (2) above are allowed. It turns out that
	some are NP-complete while others can be solved in polynomial time.
	We also derive approximation algorithms for those that are intractable
	in general.},
  doi = {10.1016/j.tcs.2010.10.015}
}

@ARTICLE{Lin2010,
  author = {Chun-Cheng Lin and Hsu-Chun Yen and Sheung-Hung Poon and Jia-Hao
	Fan},
  title = {Complexity analysis of balloon drawing for rooted trees},
  journal = {arXiv.org e-print service},
  year = {2010},
  volume = {arXiv:1004.2338v1},
  abstract = {In a balloon drawing of a tree, all the children under the same parent
	are placed on the circumference of the circle centered at their parent,
	and the radius of the circle centered at each node along any path
	from the root reflects the number of descendants associated with
	the node. Among various styles of tree drawings reported in the literature,
	the balloon drawing enjoys a desirable feature of displaying tree
	structures in a rather balanced fashion. For each internal node in
	a balloon drawing, the ray from the node to each of its children
	divides the wedge accommodating the subtree rooted at the child into
	two sub-wedges. Depending on whether the two sub-wedge angles are
	required to be identical or not, a balloon drawing can further be
	divided into two types: even sub-wedge and uneven sub-wedge types.
	In the most general case, for any internal node in the tree there
	are two dimensions of freedom that affect the quality of a balloon
	drawing: (1) altering the order in which the children of the node
	appear in the drawing, and (2) for the subtree rooted at each child
	of the node, flipping the two sub-wedges of the subtree. In this
	paper, we give a comprehensive complexity analysis for optimizing
	balloon drawings of rooted trees with respect to angular resolution,
	aspect ratio and standard deviation of angles under various drawing
	cases depending on whether the tree is of even or uneven sub-wedge
	type and whether (1) and (2) above are allowed. It turns out that
	some are NP-complete while others can be solved in polynomial time.
	We also derive approximation algorithms for those that are intractable
	in general.},
  url = {http://arxiv.org/abs/1004.2338v1}
}

@MASTERSTHESIS{Lin2008,
  author = {Xiaochuan Lin},
  title = {Algorithm for Improving the Aspect Ratio of Treemaps},
  school = {Dalhousie University, Halifax, CA},
  year = {2008},
  url = {http://web.cs.dal.ca/~farrag/lin.doc}
}

@ARTICLE{Linsen2011,
  author = {Lars Linsen and Sabine Behrendt},
  title = {Linked Treemap: A {3D} Treemap-nodelink layout for visualizing hierarchical
	structures},
  journal = {Computational Statistics},
  year = {2011},
  volume = {26},
  pages = {679--697},
  number = {4},
  abstract = {Hierarchical structures are present in many different areas of our
	daily life as well as in sciences. Visualization methods are quite
	commonly applied to support comprehension of the more complex structures.
	Nodelinks and treemaps are two widely spread directions of such visualization
	methods. Visualizations using nodelinks have the advantage of explicitly
	displaying the hierarchical relations between entities. Visualizations
	using treemaps, on the other hand, allow for a good global understanding
	of the present entities and some of their properties. We present
	a visualization tool for hierarchical structures that combines the
	advantages of treemaps and nodelinks by naturally incorporating them
	into a 3D layout. The nodelink is built upon the treemap in a direction
	orthogonal to the treemap plane. Our visualization tool supports
	various navigation techniques suitable for different analysis tasks.
	First, the user interaction allows users to render subtrees of the
	nodelink transparently. Second, the various levels can be explored
	separately in an intuitive fashion by sliding its plane through the
	orthogonal nodelink layout and, thus, moving the treemap to the respective
	level of the hierarchy. Third, zooming into regions of interest is
	supported by using a focus+context technique that operates on the
	combined 3D layout. We demonstrate the efficacy and efficiency of
	our system for visual exploration purposes in a case study that uses
	our system as a file explorer. In this context, we perform a user
	study that evaluates our approach and allows for a comparison to
	other existing approaches.},
  doi = {10.1007/s00180-011-0272-2}
}

@MISC{Lu2008a,
  author = {Hao Lu and Shi Xia Liu and Martin Wattenberg and Xi Jun Ma},
  title = {Method and System for Constructing a {Labeled Treemap} with Balanced
	Layout},
  howpublished = {United States Patent Application US 2008/0088628 A1, filed Apr. 10,
	2007, published Apr. 17},
  year = {2008},
  abstract = {The present invention provides a method and system for constructing
	a labeled treemap with balanced layout. The method comprises: determining
	a range of possible densities of leaf nodes based on designated weights
	of the leaf nodes and a designated treemap region, wherein the density
	of a leaf node is the area of region on one unit of weight occupied
	by the leaf node; searching the rang of possible densities for a
	density that could be fitted on and a labeled treemap that could
	fit on the density, wherein said density that could be fitted on
	is referred to that there is at least a labeled treemap for the density
	in which the area of region occupied by each leaf node is at least
	the product of the weight of the node and the density; and presenting
	the labeled treemap on the specified display region. By introducing
	the concept of density into labeled treemap, the present invention
	ensures the area of region occupied by each leaf node in the constructed
	labeled treemap is approximately corresponding to the weight of the
	node, and avoids the case of invisible leaf node in the treemap.},
  url = {http://www.freepatentsonline.com/y2008/0088628.html}
}

@ARTICLE{Marriott2011,
  author = {Kim Marriott and Peter Sbarski and Tim van Gelder and Daniel Prager
	and Andy Bulka},
  title = {{Hi-Trees} and Their Layout},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2011},
  volume = {17},
  pages = {290--304},
  number = {3},
  month = {March},
  abstract = {We introduce hi-trees, a new visual representation for hierarchical
	data in which, depending on the kind of parent node, the child relationship
	is represented using either containment or links. We give a drawing
	convention for hi-trees based on the standard layered drawing convention
	for rooted trees, then show how to extend standard bottom-up tree
	layout algorithms to draw hi-trees in this convention. We also explore
	a number of other more compact layout styles for layout of larger
	hi-trees and give algorithms for computing these. Finally, we describe
	two applications of hi-trees: argument mapping and business decision
	support.},
  doi = {10.1109/TVCG.2010.45}
}

@MASTERSTHESIS{Matela2010,
  author = {Mateusz Matela},
  title = {Metody wizualizacji dla zmieniajacych sie w czasie zbiorow danych
	o strukturze hierarchicznej},
  school = {Poznan University of Technology},
  year = {2010},
  url = {http://project.carrot2.org/publications/matela-2010-foamtree.pdf}
}

@MISC{Matela2011,
  author = {Mateusz Matela and Dawid Weiss},
  title = {{FoamTree}: Physics-inspired tree map},
  howpublished = {\url{http://carrotsearch.com/foamtree}},
  month = {May},
  year = {2011},
  note = {retrieved 18-JUN-2011}
}

@ARTICLE{Meier1996,
  author = {John Meier and Clifford A. Reiter},
  title = {Fractal representations of {Cayley} graphs},
  journal = {Computers and Graphics},
  year = {1996},
  volume = {20},
  pages = {163--170},
  number = {1},
  month = {January/February},
  abstract = {The visualization of Cayley graphs for many groups is possible using
	3-D models. Most of our examples are Cayley graphs of infinite groups
	where we exploit automatic structures to efficiently produce computer
	images of the Cayley graphs. The infinite groups are visualized using
	fractal rescaling so that the infinite graph projects into a bounded
	domain. Varying the color choice for these fractal representations
	of the Cayley graphs allows the visual recognition of features such
	as positivity of the total exponent of the words.},
  doi = {10.1016/0097-8493(95)00101-8}
}

@TECHREPORT{Melancon1998,
  author = {Guy Melan\c{c}on and Ivan Herman},
  title = {Circular drawings of rooted trees},
  institution = {Centrum voor Wiskunde en Informatica},
  year = {1998},
  number = {INS-R9817},
  month = {December},
  abstract = {We describe an algorithm producing circular layouts for trees, that
	is drawings, where subtrees of a node lie within circles, and these
	circles are themselves placed on the circumference of a circle. The
	complexity and methodology of our algorithm compares to Reingold
	and Tilford's algorithm for trees. Moreover, the algorithm naturally
	admits distortion transformations of the layout. This, added to its
	low complexity, makes it very well suited to be used in an interactive
	environment.},
  url = {http://repository.cwi.nl/search/fullrecord.php?publnr=4602}
}

@ARTICLE{Metaxas1998,
  author = {Panagiotis T. Metaxas and Grammati E. Pantziou and Antonis Symvonis},
  title = {A note on parallel algorithms for optimal h-v drawings of binary
	trees},
  journal = {Computational Geometry},
  year = {1998},
  volume = {9},
  pages = {145--158},
  number = {3},
  abstract = {In this paper we present a method to obtain optimal h-v drawings in
	parallel. Based on parallel tree contraction, our method computes
	optimal (with respect to a class of cost functions of the enclosing
	rectangle) drawings in O(log2n) parallel time by using a polynomial
	number of EREW processors. The number of processors reduces substantially
	when we study minimum area drawings. Our work places the problem
	of obtaining optimal size h-v drawings in NC, presenting the first
	algorithm with polylogarithmic time complexity.},
  doi = {10.1016/S0925-7721(96)00018-1}
}

@ARTICLE{Moen1990,
  author = {Sven Moen},
  title = {Drawing dynamic trees},
  journal = {IEEE Software},
  year = {1990},
  volume = {7},
  pages = {21--28},
  number = {4},
  month = {July},
  abstract = {A tree-drawing algorithm that addresses the weaknesses of current
	approaches to constructing graphical user interfaces is presented.
	Present algorithms either do not let you draw tree nodes of varying
	shapes and sizes or they draw such trees in a way that does not produce
	trees as compact as they could be, which is especially important
	when diagramming a large system. Also, they cannot reuse layout information
	when the trees changes, so after every change the layout must be
	recomputed and the tree redrawn. The main difference between these
	traditional approaches and the author's approach is that his algorithm
	is more geometric. Unlike other algorithms, it uses an explicit representation
	of node and subtree contours, and it stores every contour as a polygon.
	It has three advantages over traditional algorithms. It allows one
	to draw trees with nodes of any polygonal shape compactly. The data
	structure supports insert and delete operations on subtrees. It is
	simple to implement, yet flexible.},
  doi = {10.1109/52.56447}
}

@ARTICLE{Moret2010,
  author = {Philippe Moret and Walter Binder and Alex Villaz\'on and Danilo Ansaloni
	and Abbas Heydarnoori},
  title = {Visualizing and exploring profiles with calling context ring charts},
  journal = {Software -- Practice and Experience},
  year = {2010},
  volume = {40},
  pages = {825--847},
  number = {9},
  month = {August},
  abstract = {Calling context profiling is an important technique for analyzing
	the performance of object-oriented software with complex inter-procedural
	control flow. The Calling Context Tree (CCT) is a common data structure
	that stores dynamic metrics, such as CPU time, separately for each
	calling context. As CCTs may comprise millions of nodes, there is
	a need for a condensed visualization that eases the localization
	of performance bottlenecks. In this article, we discuss Calling Context
	Ring Charts (CCRCs), a compact visualization for CCTs, where callee
	methods are represented in ring segments surrounding the caller's
	ring segment. In order to reveal hot methods, their callers, and
	callees, the ring segments can be sized according to a chosen dynamic
	metric. We describe two case studies where CCRCs help us to detect
	and fix performance problems in applications. A performance evaluation
	also confirms that our implementation can efficiently handle large
	CCTs.},
  doi = {10.1002/spe.985}
}

@PHDTHESIS{Munzner2000,
  author = {Tamara Munzner},
  title = {Interactive visualization of large graphs and networks},
  school = {Stanford University},
  year = {2000},
  abstract = {Many real-world domains can be represented as large node-link graphs:
	backbone Internet routers connect with 70,000 other hosts, mid-sized
	Web servers handle between 20,000 and 200,000 hyperlinked documents,
	and dictionaries contain millions of words defined in terms of each
	other. Computational manipulation of such large graphs is common,
	but previous tools for graph visualization have been limited to datasets
	of a few thousand nodes. Visual depictions of graphs and networks
	are external representations that exploit human visual processing
	to reduce the cognitive load of many tasks that require understanding
	of global or local structure. We assert that the two key advantages
	of computer-based systems for information visualization over traditional
	paper-based visual exposition are interactivity and scalability.
	We also argue that designing visualization software by taking the
	characteristics of a target user's task domain into account leads
	to systems that are more effective and scale to larger datasets than
	previous work. This thesis contains a detailed analysis of three
	specialized systems for the interactive exploration of large graphs,
	relating the intended tasks to the spatial layout and visual encoding
	choices. We present two novel algorithms for specialized layout and
	drawing that use quite different visual metaphors. The H3 system
	for visualizing the hyperlink structures of web sites scales to datasets
	of over 100,000 nodes by using a carefully chosen spanning tree as
	the layout backbone, 3D hyperbolic geometry for a Focus+Context view,
	and provides a fluid interactive experience through guaranteed frame
	rate drawing. The Constellation system features a highly specialized
	2D layout intended to spatially encode domain-specific information
	for computational linguists checking the plausibility of a large
	semantic network created from dictionaries. The Planet Multicast
	system for displaying the tunnel topology of the Internet's multicast
	backbone provides a literal 3D geographic layout of arcs on a globe
	to help MBone maintainers find misconfigured long-distance tunnels.
	Each of these three systems provides a very different view of the
	graph structure, and we evaluate their efficacy for the intended
	task. We generalize these findings in our analysis of the importance
	of interactivity and specialization for graph visualization systems
	that are effective and scalable.},
  url = {http://graphics.stanford.edu/papers/munzner_thesis/}
}

@ARTICLE{Munzner1998,
  author = {Tamara Munzner},
  title = {Exploring large graphs in {3D} hyperbolic space},
  journal = {IEEE Computer Graphics and Applications},
  year = {1998},
  volume = {18},
  pages = {18--23},
  number = {4},
  month = {June/July},
  abstract = {Drawing graphs as nodes connected by links is visually compelling
	but computationally difficult. Hyperbolic space and spanning trees
	can reduce visual clutter, speed up layout, and provide fluid interaction.
	This article briefly describes a software system that explicitly
	attempts to handle much larger graphs than previous systems and support
	dynamic exploration rather than final presentation. It then discusses
	the applicability of this system to goals beyond simple exploration.
	A software system that supports graph exploration should include
	both a layout and an interactive drawing component. I have developed
	new algorithms for both layout and drawing (H3 and H3Viewer). The
	H3Viewer drawing algorithm remains under development, so this article
	presents preliminary results. I have implemented a software library
	that uses these algorithms. It can handle graphs of more than 100,000
	edges by using a spanning tree as the backbone for the layout and
	drawing algorithms.},
  doi = {10.1109/38.689657}
}

@ARTICLE{Munzner2003,
  author = {Tamara Munzner and Fran\c{c}ois Guimbreti\'ere and Serdar Tasiran
	and Li Zhang and Yunhong Zhou},
  title = {{TreeJuxtaposer}: Scalable tree comparison using Focus+Context with
	guaranteed visibility},
  journal = {ACM Transactions on Graphics},
  year = {2003},
  volume = {22},
  pages = {453--462},
  number = {3},
  month = {July},
  abstract = {Structural comparison of large trees is a difficult task that is only
	partially supported by current visualization techniques, which are
	mainly designed for browsing. We present TreeJuxtaposer, a system
	designed to support the comparison task for large trees of several
	hundred thousand nodes. We introduce the idea of "guaranteed visibility",
	where highlighted areas are treated as landmarks that must remain
	visually apparent at all times. We propose a new methodology for
	detailed structural comparison between two trees and provide a new
	nearly-linear algorithm for computing the best corresponding node
	from one tree to another. In addition, we present a new rectilinear
	Focus+Context technique for navigation that is well suited to the
	dynamic linking of side-by-side views while guaranteeing landmark
	visibility and constant frame rates. These three contributions result
	in a system delivering a fluid exploration experience that scales
	both in the size of the dataset and the number of pixels in the display.
	We have based the design decisions for our system on the needs of
	a target audience of biologists who must understand the structural
	details of many phylogenetic, or evolutionary, trees. Our tool is
	also useful in many other application domains where tree comparison
	is needed, ranging from network management to call graph optimization
	to genealogy.},
  doi = {10.1145/882262.882291}
}

@MISC{Nadeau2008,
  author = {David Robert Nadeau},
  title = {Visualizing large trees and graphs using a {3D} cone tree layout},
  howpublished = {\url{http://nadeausoftware.com/node/83}},
  month = {September},
  year = {2008},
  note = {retrieved 30-MAY-2011},
  abstract = {Tree and graph structures are often visualized as 2D linear tree diagrams
	with labeled dots and connecting lines. But when the data grows beyond
	several dozen nodes, these diagrams become large and awkward. This
	article looks at a 3D Cone Tree scheme for visualizing trees and
	graphs with several thousand nodes. I outline the layout algorithm,
	show examples, and discuss strengths and weaknesses for the approach.}
}

@MISC{Newman2005,
  author = {Paula S. Newman and Stuart K. Card},
  title = {Method and apparatus for the viewing and exploration of the content
	of hierarchical information},
  howpublished = {United States Patent US 6944818 B2, filed Sep. 10, 2001, issued Sep.
	13},
  year = {2005},
  abstract = {A method for the conversion and display of tree-structured information
	to a "treetable", a table-like display structure, in which each path
	from a root to a leaf node is represented by a single column, and
	cells representing the immediate successors of a node are placed
	immediately under that node. Variation in the amount of space given
	to cells within particular columns is used to allow more detail to
	be given for selected paths and subtrees. Extraction of subparts
	of a treetable into another such structure is used for deeper exploration
	of trees. The treetable structure is also suitable for use as a selector
	and guide to the reading, in auxiliary displays, of the concatenated
	node content associated with either (a) individual columns (representing
	full paths), or (b) all successors to a given node.},
  url = {http://www.freepatentsonline.com/6944818.html}
}

@MISC{Newman2005a,
  author = {Paula S. Newman and Stuart K. Card},
  title = {Method and apparatus for the construction and use of table-like visualizations
	of hierarchic material},
  howpublished = {United States Patent US 6976212 B2, filed Sep. 10, 2001, issued Dec.
	13},
  year = {2005},
  abstract = {A method for the conversion and display of tree-structured information
	to a "treetable", a table-like display structure, in which each path
	from a root to a leaf node is represented by a single column, and
	cells representing the immediate successors of a node are placed
	immediately under that node. Variation in the amount of space given
	to cells within particular columns is used to allow more detail to
	be given for selected paths and subtrees. Extraction of subparts
	of a treetable into another such structure is used for deeper exploration
	of trees. The treatable structure is also suitable for use as a selector
	and guide to the reading, in auxiliary displays, of the concatenated
	node content associated with either (a) individual columns (representing
	full paths), or (b) all successors to a given node.},
  url = {http://www.freepatentsonline.com/6976212.html}
}

@ARTICLE{Nguyen2005,
  author = {Quang Vinh Nguyen and Mao Lin Huang},
  title = {{EncCon}: An approach to constructing interactive visualization of
	large hierarchical data},
  journal = {Information Visualization},
  year = {2005},
  volume = {4},
  pages = {1--21},
  number = {1},
  abstract = {This paper describes a new technique called EncCon for visualizing
	and navigating large hierarchical information. This technique consists
	of two components: visualization and navigation. Visualization uses
	a fast enclosure+connection method to calculate the geometrical layout
	for the display of large hierarchies in a two-dimensional space.
	Our technique uses a rectangular division algorithm for recursively
	positioning the graph. This visualization aims to maximize the utilization
	of display space while retaining a good geometrical layout as well
	as a clear (explicit) presentation of the hierarchical structure
	of graphs. This paper also presents an experimental evaluation of
	EncCon's layout algorithm. Besides the layout algorithm, EncCon uses
	a new focus+context viewing technique for the navigation of large
	hierarchies. We use the zooming+layering concept to achieve the focus+context
	viewing, rather than the traditional enlarge+embedded concept, which
	is used by most of the available focus+context techniques. Technically,
	it employs semi-transparency to achieve the display of two layers
	of information in z-coordination at the same visualization. Both
	context view and detail view are drawn at two separate layers. These
	layers are then displayed in an overlapped manner at the same physical
	screen space.},
  doi = {10.1057/palgrave.ivs.9500087}
}

@ARTICLE{Nguyen2003,
  author = {Quang Vinh Nguyen and Mao Lin Huang},
  title = {Space-optimized tree: A connection+enclosure approach for the visualization
	of large hierarchies},
  journal = {Information Visualization},
  year = {2003},
  volume = {2},
  pages = {3--15},
  number = {1},
  abstract = {This paper describes a new approach, space-optimized tree, for the
	visualization and navigation of tree-structured relational data.
	This technique can be used especially for the display of very large
	hierarchies in a two-dimensional space. We discuss the advantages
	and limitations of current techniques of tree visualization. Our
	strategy is to optimize the drawing of trees in a geometrical plane
	and maximize the utilization of display space by allowing more nodes
	and links to be displayed at a limited screen resolution. Space-optimized
	tree is a connection+enclosure visualization approach that recursively
	positions children of a subtree into polygon areas and still uses
	a node-link diagram to present the entire hierarchical structure.
	To be able to handle the navigation of large hierarchies, we use
	a new hybrid viewing technique that combines two viewing methods,
	the modified semantic zooming and a focus+context technique. While
	the semantic zooming technique can enlarge a particular viewing area
	by filtering out the rest of tree structure from the visualization,
	the focus+context technique allows the user to interactively focus,
	view and browse the entire visual structure with a reasonable high-density
	display.},
  doi = {10.1057/palgrave.ivs.9500031}
}

@BOOK{Orr1977,
  title = {Structured Systems Development},
  publisher = {Yourdon Press},
  year = {1977},
  author = {Kenneth T. Orr},
  isbn = {0917072065},
  url = {http://www.worldcat.org/oclc/3615720}
}

@ARTICLE{Paiva2011,
  author = {Jose Gustavo S. Paiva and Laura Florian-Cruz and Helio Pedrini and
	Guilherme P. Telles and Rosane Minghim},
  title = {Improved Similarity Trees and their Application to Visual Data Classification},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2011},
  volume = {17},
  pages = {2459--2468},
  number = {12},
  month = {December},
  abstract = {An alternative form to multidimensional projections for the visual
	analysis of data represented in multidimensional spaces is the deployment
	of similarity trees, such as Neighbor Joining trees. They organize
	data objects on the visual plane emphasizing their levels of similarity
	with high capability of detecting and separating groups and subgroups
	of objects. Besides this similarity-based hierarchical data organization,
	some of their advantages include the ability to decrease point clutter;
	high precision; and a consistent view of the data set during focusing,
	offering a very intuitive way to view the general structure of the
	data set as well as to drill down to groups and subgroups of interest.
	Disadvantages of similarity trees based on neighbor joining strategies
	include their computational cost and the presence of virtual nodes
	that utilize too much of the visual space. This paper presents a
	highly improved version of the similarity tree technique. The improvements
	in the technique are given by two procedures. The first is a strategy
	that replaces virtual nodes by promoting real leaf nodes to their
	place, saving large portions of space in the display and maintaining
	the expressiveness and precision of the technique. The second improvement
	is an implementation that significantly accelerates the algorithm,
	impacting its use for larger data sets. We also illustrate the applicability
	of the technique in visual data mining, showing its advantages to
	support visual classification of data sets, with special attention
	to the case of image classification. We demonstrate the capabilities
	of the tree for analysis and iterative manipulation and employ those
	capabilities to support evolving to a satisfactory data organization
	and classification.},
  doi = {10.1109/TVCG.2011.212}
}

@ARTICLE{Parks2009b,
  author = {Donovan Parks and Norman MacDonald and Robert Beiko},
  title = {Tracking the evolution and geographic spread of {Influenza A}},
  journal = {PLoS Currents},
  year = {2009},
  abstract = {The 2009 swine-origin strain of Influenza A H1N1 has spread to nearly
	all parts of the world, with 175 countries reporting confirmed cases
	thus far. Consistent with seasonal flu outbreaks, the current pandemic
	strain has shown rapid dispersal, with multiple examples of introduction
	into different geographic regions. Here we use an automated pipeline
	to collect data for analysis in the geospatial package GenGIS, which
	allows the geographic and temporal tracking of new sequence types
	and polymorphisms. Using this approach, we examine a pair of amino
	acid changes in the neuraminidase protein that are implicated in
	antibody recognition, and exhibit global dispersal with little or
	no geographic structure.},
  doi = {10.1371/currents.RRN1014}
}

@ARTICLE{Parks2009a,
  author = {Donovan H. Parks and Michael Porter and Sylvia Churcher and Suwen
	Wang and Christian Blouin and Jacqueline Whalley and Stephen Brooks
	and Robert G. Beiko},
  title = {{GenGIS}: A geospatial information system for genomic data},
  journal = {Genome Research},
  year = {2009},
  volume = {19},
  pages = {1896-1904},
  abstract = {The increasing availability of genetic sequence data associated with
	explicit geographic and ecological information is offering new opportunities
	to study the processes that shape biodiversity. The generation and
	testing of hypotheses using these data sets requires effective tools
	for mathematical and visual analysis that can integrate digital maps,
	ecological data, and large genetic, genomic, or metagenomic data
	sets. GenGIS is a free and open-source software package that supports
	the integration of digital map data with genetic sequences and environmental
	information from multiple sample sites. Essential bioinformatic and
	statistical tools are integrated into the software, allowing the
	user a wide range of analysis options for their sequence data. Data
	visualizations are combined with the cartographic display to yield
	a clear view of the relationship between geography and genomic diversity,
	with a particular focus on the hierarchical clustering of sites based
	on their similarity or phylogenetic proximity. Here we outline the
	features of GenGIS and demonstrate its application to georeferenced
	microbial metagenomic, HIV-1, and human mitochondrial DNA data sets.},
  doi = {10.1101/gr.095612.109}
}

@ARTICLE{Pavlo2006,
  author = {Andrew Pavlo and Christopher Homan and Jonathan Schull},
  title = {A parent-centered radial layout algorithm for interactive graph visualization
	and animation},
  journal = {arXiv.org e-print service},
  year = {2006},
  volume = {arXiv:cs/0606007v1},
  abstract = {We have developed (1) a graph visualization system that allows users
	to explore graphs by viewing them as a succession of spanning trees
	selected interactively, (2) a radial graph layout algorithm, and
	(3) an animation algorithm that generates meaningful visualizations
	and smooth transitions between graphs while minimizing edge crossings
	during transitions and in static layouts. Our system is similar to
	the radial layout system of Yee et al. (2001), but differs primarily
	in that each node is positioned on a coordinate system centered on
	its own parent rather than on a single coordinate system for all
	nodes. Our system is thus easy to define recursively and lends itself
	to parallelization. It also guarantees that layouts have many nice
	properties, such as: it guarantees certain edges never cross during
	an animation. We compared the layouts and transitions produced by
	our algorithms to those produced by Yee et al. Results from several
	experiments indicate that our system produces fewer edge crossings
	during transitions between graph drawings, and that the transitions
	more often involve changes in local scaling rather than structure.
	These findings suggest the system has promise as an interactive graph
	exploration tool in a variety of settings.},
  url = {http://arxiv.org/abs/cs/0606007v1}
}

@ARTICLE{Penna2002,
  author = {Paolo Penna},
  title = {On the approximability of two tree drawing conventions},
  journal = {Information Processing Letters},
  year = {2002},
  volume = {82},
  pages = {237--242},
  number = {5},
  month = {June},
  abstract = {We consider two aesthetic criteria for the visualization of rooted
	trees: inclusion and tip-over. Finding the minimum area layout according
	to either of these two standards is an NP-hard task, even when we
	restrict ourselves to binary trees. We provide a fully polynomial
	time approximation scheme for this problem. This result applies to
	any tree for tip-over layouts and to bounded degree trees in the
	case of the inclusion convention. We also prove that such restriction
	is necessary since, for unbounded degree trees, the inclusion problem
	is strongly NP-hard. Hence, neither a fully polynomial time approximation
	scheme nor a pseudopolynomial time algorithm exists, unless P=NP.
	Our technique, combined with the parallel algorithm by Metaxas et
	al., also yields an NC fully parallel approximation scheme. This
	latter result holds for inclusion of binary trees and for the slicing
	floorplanning problem. Although this problem is in P, it is unknown
	whether it belongs to NC or not. All the above results also apply
	to other size functions of the drawing (e.g., the perimeter).},
  doi = {10.1016/S0020-0190(01)00280-0}
}

@MISC{Pulo2003b,
  author = {Kevin Pulo and Peter Eades and Masahiro Takatsuko},
  title = {Smooth Structural Zooming as a Tool for Navigating Large Inclusion
	Hierarchies},
  howpublished = {poster presentation at the Softvis'03: ACM Symposium on Software
	Visualization},
  month = {June},
  year = {2003},
  abstract = {We present a new method for achieving Focus+Context visualizations
	called smooth structural zooming, which varies the level of detail
	of the data being visualized, rather than geometrically distorting
	the visualization. We apply a preliminary smooth structural zooming
	technique to the horizontal-vertical (h-v) inclusion tree layout
	convention, in particular Design Behaviour Trees (DBTs). We illustrate
	several advantages of this system, including the ability to navigate
	and explore inclusion tree layout data too large to be displayed
	at once, keeping good layouts at all times and preserving the user's
	mental map with animation.},
  url = {http://www.kev.pulo.com.au/publications/softvis03-poster/softvis03-kpulo-poster.pdf}
}

@MISC{Rafelsberger2007,
  author = {Walter Rafelsberger},
  title = {3D family tree visualization using Rhizome Navigation},
  howpublished = {part of a documentary by Benedikt Bjarnason},
  year = {2007},
  abstract = {For an upcoming documentary by Benedikt Bjarnason, Rhizome Navigation
	was used to create animated visualizations of large genealogy data
	sets. The graph layout was done using an adapted force-directed algorithm
	and features more than 3300 persons. What set's it apart from similar
	visualizations is the capability to show far more complex relationships
	by breaking up the classic tree structure and following a more rhizome-like
	approach - and of course the sheer amount of relationships shown.}
}

@ARTICLE{Reingold1981,
  author = {Edward M. Reingold and John S. Tilford},
  title = {Tidier Drawings of Trees},
  journal = {IEEE Transactions on Software Engineering},
  year = {1981},
  volume = {SE-7},
  pages = {223--228},
  number = {2},
  month = {March},
  abstract = {Various algorithms have been proposed for producing tidy drawings
	of trees - drawings that are aesthetically pleasing and use minimum
	drawing space. We show that these algorithms contain some difficulties
	that lead to aesthetically unpleasing, wider than necessary drawings.
	We then present a new algorithm with comparable time and storage
	requirements that produces tidier drawings. Generalizations to forests
	and m-ary trees are discussed, as are some problems in discretization
	when alphanumeric output devices are used.},
  doi = {10.1109/TSE.1981.234519}
}

@MISC{Robertson1994,
  author = {George G. Robertson and Jock Mackinlay and Stuart K. Card},
  title = {Display of hierarchical three-dimensional structures with rotating
	substructures},
  howpublished = {United States Patent US 5295243, filed May 21, 1993, issued Mar.
	15},
  year = {1994},
  abstract = {A processor presents a sequence of images of a hierarchical structure
	that is perceived as three-dimensional. The hierarchical structure
	includes conic substructures that can have vertical or horizontal
	axes. Each cone has a parent node at its vertex and children nodes
	along its base, each with a link to the parent node. Each child can
	in turn be at the vertex of another cone. The cones can be rotated
	in steps that produce the perception of object constancy for each
	node. For example, if the user requests that an indicated node be
	moved to a primary viewing position, each of the cones along the
	path from the indicated node to the root node is rotated in the direction
	that most directly moves the indicated node to the primary viewing
	position. Each node can include a selectable unit for indicating
	it, and a node can also include a grow tab that can be selected to
	request presentation of its children nodes and links to them. The
	user can request that the children nodes of a node be replaced by
	a grow tab. To reduce the computation necessary for each step of
	rotation, the position relative to a cone's axis for each of 80 points
	on the base of a cone is computed for a level of the hierarchy and
	is then stored in an array for subsequent use in positioning nodes
	on that level. The base point of each node on a rotating cone can
	then be changed in a linked node data structure, and its new position
	can then be obtained by simple arithmetic operations using the axis
	coordinates and the appropriate data from the array. The base of
	each array can be a polygon whose vertices are nodes, and the base
	shape can be presented as a shadow to provide additional information
	and strengthen the perception of three dimensions. Or, the profiles
	of the cones can be presented as a shadow.},
  url = {http://www.freepatentsonline.com/5295243.html}
}

@MISC{Rusu2011,
  author = {Adrian Rusu and Confesor Santiago},
  title = {Information visualization system},
  howpublished = {United States Patent US 7984389 B2, filed Jan. 26, 2007, issued Jul.
	19},
  year = {2011},
  abstract = {A Web browsing and visualization system and method wherein: (i) Web
	data is retrieved and displayed in real-time (i.e., Web data is not
	pre-recorded), (ii) browsing and visualization are synchronized together
	in the same interface, (iii) a tree-based, rings-type visualization
	engine, (iv) space-efficient display of visualization, and (v) the
	amount of resources needed from the host computer is comparatively
	modest. In addition, the tree-based rings engine used to create the
	visualization displays the information in a smaller area than previous
	systems. Thus, the system requires less screen space to display the
	same amount of information as comparable systems. Alternatively,
	it can display more information to the user in the same amount of
	screen space as comparable systems. Moreover, although the present
	invention is disclosed herein in connection with visualizing Web
	data, it can be applied to portray any information hierarchy.},
  url = {http://www.freepatentsonline.com/7984389.html}
}

@MISC{Sandberg2007,
  author = {Anders Sandberg},
  title = {Hilbert Tree of Life},
  howpublished = {\url{http://www.flickr.com/photos/arenamontanus/1916189332/in/set-72157594326128194/}},
  month = {November},
  year = {2007},
  note = {retrieved 26-APR-2010}
}

@ARTICLE{Schonlau2002,
  author = {Matthias Schonlau},
  title = {The {Clustergram}: A graph for visualizing hierarchical and nonhierarchical
	cluster analyses},
  journal = {The Stata Journal},
  year = {2002},
  volume = {2},
  pages = {391--402},
  number = {4},
  abstract = {In hierarchical cluster analysis, dendrograms are used to visualize
	how clusters are formed. I propose an alternative graph called a
	“clustergram” to examine how cluster members are assigned to clusters
	as the number of clusters increases. This graph is useful in exploratory
	analysis for nonhierarchical clustering algorithms such as k-means
	and for hierarchical cluster algorithms when the number of observations
	is large enough to make dendrograms impractical. I present the Stata
	code and give two examples.},
  url = {http://www.stata-journal.com/article.html?article=st0028}
}

@ARTICLE{Schuffenhauer2007,
  author = {Ansgar Schuffenhauer and Peter Ertl and Silvio Roggo and Stefan Wetzel
	and Marcus A. Koch and Herbert Waldmann},
  title = {The {Scaffold Tree} -- Visualization of the Scaffold Universe by
	Hierarchical Scaffold Classification},
  journal = {Journal of Chemical Information and Modeling},
  year = {2007},
  volume = {47},
  pages = {47--58},
  number = {1},
  abstract = {A hierarchical classification of chemical scaffolds (molecular framework,
	which is obtained by pruning all terminal side chains) has been introduced.
	The molecular frameworks form the leaf nodes in the hierarchy trees.
	By an iterative removal of rings, scaffolds forming the higher levels
	in the hierarchy tree are obtained. Prioritization rules ensure that
	less characteristic, peripheral rings are removed first. All scaffolds
	in the hierarchy tree are well-defined chemical entities making the
	classification chemically intuitive. The classification is deterministic,
	data-set-independent, and scales linearly with the number of compounds
	included in the data set. The application of the classification is
	demonstrated on two data sets extracted from the PubChem database,
	namely, pyruvate kinase binders and a collection of pesticides. The
	examples shown demonstrate that the classification procedure handles
	robustly synthetic structures and natural products.},
  doi = {10.1021/ci600338x}
}

@ARTICLE{Schulz2011,
  author = {Hans-J\"org Schulz and Steffen Hadlak and Heidrun Schumann},
  title = {The Design Space of Implicit Hierarchy Visualization: A Survey},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2011},
  volume = {17},
  pages = {393--411},
  number = {4},
  month = {April},
  note = {to appear},
  abstract = {Apart from explicit, node-link representations, implicit visualizations
	and especially the Treemap as their frontrunner have acquired a solid
	position among the available techniques to visualize hierarchies.
	Their advantage is an extremely space-efficient graphical representation
	that does not require explicit drawing of edges. In this paper, we
	survey the design space for this class of visualization techniques.
	For that purpose, we first establish the design space along the four
	axes of dimensionality, edge representation, node representation,
	and layout by examining most of the existing implicit hierarchy visualization
	techniques. The survey is completed by an outlook to the so far unexplored
	regions of the design space by giving a few examples of novel combinations
	of design parameters. Furthermore, we ensure that our design space
	is not a mere theoretical construct, but a practically usable tool
	for rapid visualization development by discussing and presenting
	a concrete software implementation of the introduced design space.},
  doi = {10.1109/TVCG.2010.79}
}

@ARTICLE{Schulz2011a,
  author = {Hans-J\"org Schulz and Steffen Hadlak and Heidrun Schumann},
  title = {Point-Based Visualization for Large Hierarchies},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2011},
  volume = {17},
  pages = {598--611},
  number = {5},
  month = {May},
  note = {to appear},
  abstract = {Space-filling layout techniques for tree representations are frequently
	used when the available screen space is small or the data set is
	large. In this paper, we propose an efficient approach to space-filling
	tree representations, which uses mechanisms from the point-based
	rendering paradigm. We relate this new layout approach to common
	layout mechanisms and present helpful interaction techniques that
	tie in with our layout. Additionally, we compare and contrast the
	new layout with established space-filling techniques in a preliminary
	user study and along the lines of a numerical evaluation using the
	measures of the Ink-Paper-Ratio and overplotted\%. The flexibility
	of the general approach is illustrated by several enhancements of
	the basic layout, as well as its usage within the context of two
	software frameworks from different application fields.},
  doi = {10.1109/TVCG.2010.89}
}

@ARTICLE{Schumann2011,
  author = {Heidrun Schumann and Christian Tominski},
  title = {Analytical, visual and interactive concepts for geo-visual analytics},
  journal = {Journal of Visual Languages and Computing},
  year = {2011},
  volume = {22},
  pages = {257--267},
  number = {4},
  abstract = {Supporting the visual analysis of structured multivariate geo-spatial
	data is a challenging task involving many different aspects. In this
	paper, we describe a systematic view of this task based on Chi's
	data state reference model. The analytical, visual and interaction
	components of the systematic view will be instantiated with specific
	examples that demonstrate how their tight interconnection facilitates
	exploration and analysis of geo-spatial data. In particular, we address
	the visualization of hierarchical structures on maps applying an
	extended focus+context concept. Moreover, we introduce an approach
	to extracting association rules from geo-spatial data and visualizing
	them on maps.},
  doi = {10.1016/j.jvlc.2011.03.002}
}

@PHDTHESIS{Shiloach1976,
  author = {Yossi Shiloach},
  title = {Arrangements of Planar Graphs on the Planar Lattice},
  school = {Weizmann Institute of Science},
  year = {1976},
  url = {http://proquest.umi.com/pqdweb?did=1885086831&Fmt=2&RQT=309}
}

@ARTICLE{Shin2011,
  author = {HyunJu Shin and GwangHyun Park and JungHyun Han},
  title = {Tablorer -- An Interactive Tree Visualization System for Tablet {PCs}},
  journal = {Computer Graphics Forum},
  year = {2011},
  volume = {30},
  pages = {1131--1140},
  number = {3},
  month = {June},
  abstract = {A variety of mobile devices are available today, but there is no dominant
	tree visualization system in the devices. This paper proposes Tablorer,
	a novel interactive tree visualization system for medium-sized mobile
	devices, especially for tablet PCs. The system shows the hierarchical
	information with a compact way using an expandable table format.
	For efficient navigation, the system provides an integrated view
	of context and focus information. The experimental results show that
	Tablorer can reduce the search time by about 22\%.},
  doi = {10.1111/j.1467-8659.2011.01962.x}
}

@ARTICLE{Shneiderman1992,
  author = {Ben Shneiderman},
  title = {Tree visualization with tree-maps: 2-d space-filling approach},
  journal = {ACM Transactions on Graphics},
  year = {1992},
  volume = {11},
  pages = {92--99},
  number = {1},
  abstract = {This paper presents a novel approach to representing trees that have
	weights or sizes on the leaf nodes. The 2-d visualization is space
	filling and the recursive algorithm for generation runs rapidly.
	It depends on color coding (or shading) of regions and easily provides
	users with a quick overview that clearly indicates relative sizes
	of the leaf nodes. Figures 3 and 4 show examples of tree-maps with
	size coding, as implemented by Brian Johnson on an Apple Macintosh
	II computer with a high resolution color display. Figure 3 shows
	fifteen files in four directories at three levels, with nested boxes
	to show the levels. Figure 4 represents actual disk directories encompassing
	850 files at four levels with color coding by file type (text, graphics,
	applications, etc.). We continue to explore refinements of tree-maps
	such as alternate layouts, better methods for coping with large ranges
	of file size, color coding schemes and operations applied to files.},
  doi = {10.1145/102377.115768}
}

@ARTICLE{Slack2006,
  author = {James Slack and Kristian Hildebrand and Tamara Munzner},
  title = {{PRISAD}: A Partitioned Rendering Infrastructure for Scalable Accordion
	Drawing (Extended Version)},
  journal = {Information Visualization},
  year = {2006},
  volume = {5},
  pages = {137--151},
  number = {2},
  abstract = {We present PRISAD, the first generic rendering infrastructure for
	information visualization applications that use the accordion drawing
	technique: rubber-sheet navigation with guaranteed visibility for
	marked areas of interest. Our new rendering algorithms are based
	on the partitioning of screen-space, which allows us to handle dense
	data set regions correctly. The algorithms in previous work led to
	incorrect visual representations because of overculling, and to inefficiencies
	due to overdrawing multiple items in the same region. Our pixel-based
	drawing infrastructure guarantees correctness by eliminating over-culling,
	and improves rendering performance with tight bounds on overdrawing.
	PRITree and PRISeq are applications built on PRISAD, with the feature
	sets of TreeJuxtaposer and SequenceJuxtaposer, respectively. We describe
	our PRITree and PRISeq data set traversal algorithms, which are used
	for efficient rendering, culling, and layout of data sets within
	the PRISAD framework. We also discuss PRITree node marking techniques,
	which offer order-of-magnitude improvements to both memory and time
	performance vs previous range storage and retrieval techniques. Our
	PRITree implementation features a fivefold increase in rendering
	speed for non-trivial tree structures, and also reduces memory requirements
	in some real-world data sets by up to eight times, so we are able
	to handle trees of several million nodes. PRISeq renders 15 times
	faster and handles data sets 20 times larger than previous work.
	The software is available as open source from http://olduvai.sourceforge.net.},
  doi = {10.1057/palgrave.ivs.9500118}
}

@ARTICLE{Slingsby2008,
  author = {Aidan Slingsby and Jason Dykes and Jo Wood},
  title = {Using {Treemaps} for variable selection in spatio-temporal visualisation},
  journal = {Information Visualization},
  year = {2008},
  volume = {7},
  pages = {210--224},
  number = {3},
  abstract = {We demonstrate and reflect upon the use of enhanced treemaps that
	incorporate spatial and temporal ordering for exploring a large multivariate
	spatio-temporal data set. The resulting data-dense views summarise
	and simultaneously present hundreds of space-, time-, and variable-constrained
	subsets of a large multivariate data set in a structure that facilitates
	their meaningful comparison and supports visual analysis. Interactive
	techniques allow localised patterns to be explored and subsets of
	interest selected and compared with the spatial aggregate. Spatial
	variation is considered through interactive raster maps and high-resolution
	local road maps. The techniques are developed in the context of 42.2
	million records of vehicular activity in a 98 sqkm area of central
	London and informally evaluated through a design used in the exploratory
	visualisation of this data set. The main advantages of our technique
	are the means to simultaneously display hundreds of summaries of
	the data and to interactively browse hundreds of variable combinations
	with ordering and symbolism that are consistent and appropriate for
	space- and time-based variables. These capabilities are difficult
	to achieve in the case of spatio-temporal data with categorical attributes
	using existing geovisualisation methods. We acknowledge limitations
	in the treemap representation but enhance the cognitive plausibility
	of this popular layout through our two-dimensional ordering algorithm
	and interactions. Patterns that are expected (e.g. more traffic in
	central London), interesting (e.g. the spatial and temporal distribution
	of particular vehicle types) and anomalous (e.g. low speeds on particular
	road sections) are detected at various scales and locations using
	the approach. In many cases, anomalies identify biases that may have
	implications for future use of the data set for analyses and applications.
	Ordered treemaps appear to have potential as interactive interfaces
	for variable selection in spatio-temporal visualisation.},
  doi = {10.1057/palgrave.ivs.9500185}
}

@TECHREPORT{Solo1986,
  author = {David M. Solo},
  title = {Readable Layout of Unbalanced N-ary Trees},
  institution = {MIT Artificial Intelligence Laboratory},
  year = {1986},
  number = {WP-289},
  abstract = {The automatic layout of unbounded n-ary tree structures is a problem
	of subjectively meshing two independent goals: clarity and space
	efficiency. This paper presents a minimal set of subjective aesthetics
	which insures highly readable structures, without overly restricted
	flexibility in the layout of the tree. This flexibility underlies
	the algorithm's ability to produce readable trees with greater uniformity
	of node density throughout the display than achieved by previous
	algorithms, an especially useful characteristic where nodes are labelled
	with text.},
  url = {http://hdl.handle.net/1721.1/41166}
}

@ARTICLE{Song2011,
  author = {Hongzhi Song and Xu Cai and Yi Fu},
  title = {Rectangular Tree Browser: a Navigation and Visualization Tool for
	Large Hierarchies},
  journal = {Journal of Information and Computational Science},
  year = {2011},
  volume = {8},
  pages = {354--361},
  number = {2},
  abstract = {Hierarchies, also known as trees, is a good means to manage information.
	Therefore handling hierarchical data structures becomes an important
	task in the field of information visualization. Focus+context concept
	is a well-known strategy to cope with the representation of large
	collections of data. This concept has been applied to many tools
	for visualizing large hierarchies, such as Hyperbolic Browser, SpaceTree,
	DOI Tree, etc. Despite the success of these tools, they could not
	adequately utilize the display space. We propose a technique named
	Rectangular Tree Browser for the visualization and navigation of
	large hierarchies. The technique lays out the tree on an imaginary
	geometrical plane with the root in the center, and then transforms
	and maps the plane to a limited rectangle area rather than an ellipse
	area as Hyperbolic Browser does. Comparing with Hyperbolic Browser,
	our browser makes better use of the display space. Moreover, because
	regular user interface components are rectangular, by doing this
	transformation, the browser is easy to be integrated into a user
	interface that contains more components. We conducted an informal
	user test with five users performing navigation and selection tasks.
	Through observation and interview, we found that our users didn't
	experience any uncomfortability. We believe that Rectangular Tree
	Browser has the potential to be a good tool for navigation and visualization
	of large hierarchies.},
  url = {http://www.joics.com/publishedpapers/2011_8_2_354_361.pdf}
}

@ARTICLE{Song2004,
  author = {Hongzhi Song and Edwin P. Curran and Roy Sterritt},
  title = {Multiple foci visualisation of large hierarchies with {FlexTree}},
  journal = {Information Visualization},
  year = {2004},
  volume = {3},
  pages = {19--35},
  number = {1},
  abstract = {One of the main tasks in information visualisation research is creating
	visual tools to facilitate human understanding of large and complex
	information spaces. Hierarchies, being a good mechanism for organising
	such information, are ubiquitous. Although much research effort has
	been spent on finding useful representations for hierarchies, visualising
	large hierarchies is still a difficult topic. One of the difficulties
	is how to handle the ever increasing scale of hierarchies. Another
	is how to enable the user to focus on multiple selections of interest
	while maintaining context. This paper describes a hierarchy visualisation
	technique called FlexTree to address these problems. It contains
	some important features that have not been exploited so far. A profile
	or contour unique to the hierarchy being visualised can be viewed
	in a bar chart layout. A normalised view of a common attribute of
	all nodes can be selected by the user. Multiple foci are consistently
	accessible within a global context through interaction. Furthermore
	it can handle a large hierarchy that contains 10,000 nodes in a PC
	environment. This technique has been applied to visualise computer
	file system structures and decision trees from data mining results.
	The results from informal user evaluations against these two applications
	are also presented. User feedback suggests that FlexTree is suitable
	for visualising large decision trees.},
  doi = {10.1057/palgrave.ivs.9500065}
}

@ARTICLE{Stasko2000a,
  author = {John Stasko and Richard Catrambone and Marc Guzdial and Kevin McDonald},
  title = {An evaluation of space-filling information visualizations for depiction
	hierarchical structures},
  journal = {International Journal of Human-Computer Studies},
  year = {2000},
  volume = {53},
  pages = {663--694},
  number = {5},
  abstract = {A variety of information visualization tools have been developed recently,
	but relatively little effort has been made to evaluate the effectiveness
	and utility of the tools. This article describes results from two
	empirical studies of two visualization tools for depicting hierarchies,
	in particular, computer file and directory structures. The two tools
	examined implement space-filling methodologies, one rectangular,
	the Treemap method, and one circular, the Sunburst method. Participants
	performed typical file/directory search and analysis tasks using
	the two tools. In general, performance trends favored the Sunburst
	tool with respect to correct task performance, particularly on initial
	use. Performance with Treemap tended to improve over time and use,
	suggesting a greater learning cost that was partially recouped over
	time. Each tool afforded somewhat different search strategies, which
	also appeared to influence performance. Finally, participants strongly
	preferred the Sunburst tool, citing better ability to convey structure
	and hierarchy.},
  doi = {10.1006/ijhc.2000.0420}
}

@ARTICLE{Stockmeyer1983,
  author = {Larry Stockmeyer},
  title = {Optimal orientations of cells in slicing floorplan designs},
  journal = {Information and Control},
  year = {1983},
  volume = {57},
  pages = {91--101},
  number = {2-3},
  month = {May-June},
  abstract = {A methodology of VLSI layout described by several authors first determines
	the relative positions of indivisible pieces, called cells, on the
	chip. Various optimizations are then performed on this initial layout
	to minimize some cost measure such as chip area or perimeter. If
	each cell is a rectangle with given dimensions, one optimization
	problem is to choose orientations of all the cells to minimize the
	cost measure. A polynomial time algorithm is given for this optimization
	problem for layouts of a special type called slicings. However, orientation
	optimization for more general layouts is shown to be NP-complete
	(in the strong sense).},
  doi = {10.1016/S0019-9958(83)80038-2}
}

@MISC{Strasnick1996,
  author = {Steven L. Strasnick and Joel D. Tesler},
  title = {Method and apparatus for displaying data within a three-dimensional
	information landscape},
  howpublished = {United States Patent US 5528735, filed Mar. 23, 1993, issued Jun.
	18},
  year = {1996},
  abstract = {A method and apparatus are presented for displaying three-dimensional
	navigable display space containing an aggregation of graphical objects
	and an overview of the aggregation of display objects. An altered
	perspective is provided by compressing the horizontal dimension of
	the displayed objects so that a user can see a representative overview
	of the entire aggregation of display objects that have been selected
	for display together on a display screen. The compressed component
	is expanded so that the objects appear wider as a navigator approaches
	the displayed objects. A spotlight shines down on objects responsive
	to a data query. The spotlight serves as a navigation aid to the
	navigator so that highlighted items are visible from a distance and
	can be easily located. The user's view of the display space is altered
	so that the navigator perceives that he is traveling in a straight
	line when approaching a display object in a display space in which
	the horizontal dimension of displayed objects is compressed in accordance
	with the apparent distance between a displayed object and the navigator.},
  url = {http://www.freepatentsonline.com/5528735.html}
}

@MISC{Strasnick1996a,
  author = {Steven L. Strasnick and Joel D. Tesler},
  title = {Method and apparatus for navigation within three-dimensional information
	landscape},
  howpublished = {United States Patent US 5555354, filed Mar. 23, 1993, issued Sep.
	10},
  year = {1996},
  abstract = {A method and apparatus for navigating within a three dimensional graphic
	display space and manipulating information and data represented by
	objects in display space. The method and apparatus presents users
	with a vastly expanded view of their data, displayed with a richer
	dimensionality. Data objects represented by graphic objects are arranged
	into a navigable landscape representing the containership and contextual
	relations of the underlying data. The graphic objects are columns,
	pedestals and disks, which represent data blocks, cells, and comparative
	values respectively. The columns rest on the pedestals. The disks
	are located with respect to the top of the column to signify a comparative
	attribute. The pedestal rest upon a ground plane. The ground plane
	represents a threshold value. Data attributes may be represented
	by visual, textual, executable, or audible characteristics of the
	display. The user may interact with the data to affect change in
	the underlying data or its representation within the display space.
	Less detail is displayed as the user navigates away from objects
	within the display space. Objects change from three-dimensional to
	two-dimensional, to line segments as the user moves away from the
	objects. Visible attributes such as text and icons are not displayed
	for distant objects.},
  url = {http://www.freepatentsonline.com/5555354.html}
}

@MISC{Sukla2005,
  author = {Ambika Sukla and Mohit Sauhta},
  title = {Nested Pie Chart},
  howpublished = {\url{http://nestedpiechart.sourceforge.net/}},
  year = {2005},
  note = {retrieved 26-JUL-2011},
  abstract = {A pie chart divides a circle or ellipse into slices, where the size
	and color of each slice is based on some attributes of the elements
	it represents. For example, one can show the constituents of a stock
	porfolio in a pie-chart, where each slice will be occupied by one
	stock and the size of the slice will be decided by the total value
	of the portfolio, and the color determined by percentage price change.
	A Nested Pie Chart extends the functionality of a pie-chart by adding
	letting it represent a tree data model, thus making it a elliptical
	heatmap.}
}

@TECHREPORT{Sun2003,
  author = {Lisong Sun and Steve Smith and Thomas Preston Caudell},
  title = {A Low Complexity Recursive Force-Directed Tree Layout Algorithm Based
	on the {Lennard-Jones} Potential},
  institution = {University of New Mexico},
  year = {2003},
  number = {EECE-TR-03-001},
  abstract = {In this paper, a low complexity force-directed tree layout algorithm
	based on the Lennard-Jones potential is described. The recursive
	method lays out sub-trees as small disks contained in their parent
	disk. Inside each disk, children disks are dynamically laid out using
	a new force directed simulation. Unlike most other force directed
	layout methods which run in quadratic time for each simulation step,
	this algorithm runs in O(n**(m+1)/m) time per each step for a tree
	with n nodes, depth m and all the nodes having uniform number of
	children. The layout uses space efficiently and reflects both global
	structure and local detail. The method supports runtime insertion
	and deletion. Both operations and the evolving process are rendered
	with smooth animation to preserve visual continuity. The method could
	be used to monitor in real time, visualize and analyze a wide variety
	of data which has a rooted tree structure, e.g. internet hosts could
	be laid out by domain name (DNS) hierarchies. This paper gives a
	description of the algorithm, a complexity analysis and an example
	of how the algorithm is implemented to visualize DNS tree.},
  url = {http://www.eece.unm.edu/techreports/trds/eece-tr-03-001.pdf}
}

@ARTICLE{Tan2007,
  author = {Desney S. Tan and Greg Smith and Bongshin Lee and George G. Robertson},
  title = {{AdaptiviTree}: Adaptive Tree Visualization for Tournament-Style
	Brackets},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2007},
  volume = {13},
  pages = {1113-1120},
  number = {6},
  month = {November-December},
  abstract = {Online pick'em games, such as the recent NCAA college basketball March
	Madness tournament, form a large and rapidly growing industry. In
	these games, players make predictions on a tournament bracket that
	defines which competitors play each other and how they proceed toward
	a single champion. Throughout the course of the tournament, players
	monitor the brackets to track progress and to compare predictions
	made by multiple players. This is often a complex sense making task.
	The classic bracket visualization was designed for use on paper and
	utilizes an incrementally additive system in which the winner of
	each match-up is rewritten in the next round as the tournament progresses.
	Unfortunately, this representation requires a significant amount
	of space and makes it relatively difficult to get a quick overview
	of the tournament state since competitors take arbitrary paths through
	the static bracket. In this paper, we present AdaptiviTree, a novel
	visualization that adaptively deforms the representation of the tree
	and uses its shape to convey outcome information. AdaptiviTree not
	only provides a more compact and understandable representation, but
	also allows overlays that display predictions as well as other statistics.
	We describe results from a lab study we conducted to explore the
	efficacy of AdaptiviTree, as well as from a deployment of the system
	in a recent real-world sports tournament.},
  doi = {10.1109/TVCG.2007.70537}
}

@MISC{Tan2009,
  author = {Desney S. Tan and Gregory R. Smith and Bongshin Lee and George G.
	Robertson},
  title = {Adaptive tree visualization for tournament-style brackets},
  howpublished = {United States Patent Application US 2009/0098937 A1, filed Oct. 12,
	2007, published Apr. 16},
  year = {2009},
  abstract = {An adaptive tree visualization system and method for adaptively deforming
	a traditional bracket tree to visualize information about competitors
	in a linear manner. A one-dimensional result line emanates from the
	name of each competitor such that the progress of each competitor
	can be immediately determined by examining the length of the competitor's
	result line. The result line typically is composed of multiple result
	line segments. Each line segment spans a particular time period column
	to indicate that the competitor is matched up with another competitor
	during that time period. A pending result line segment spans the
	adjacent time period to indicate that the results of the match-up
	are unknown. Once the result of the match-up is known, the pending
	result line is added to the result line segment of the winning competitor.
	This extends the winner's result line into the next time period while
	the loser's result line remains unchanged.},
  url = {http://www.freepatentsonline.com/y2009/0098937.html}
}

@MISC{Tesler2000,
  author = {Joel D. Tesler},
  title = {Method, system, and computer program product for visualizing data
	using partial hierarchies},
  howpublished = {United States Patent US 6137499, filed Mar. 07, 1997, issued Oct.
	24},
  year = {2000},
  abstract = {A method, system, and computer program product provides data visualization
	which optimizes visualization of and navigation through hierarchies.
	A partial hierarchy is generated and displayed. The partial hierarchy
	consists of a number levels at least equal to a predetermined depth
	and less than a total number of levels included in a corresponding
	complete hierarchy. Parent nodes in the bottom level of the partial
	hierarchy have segments of connection lines extending toward child
	nodes not included in the partial hierarchy. A user is permitted
	to mark selected nodes or locations in a displayed partial hierarchy.
	Partial hierarchies are generated and stored in a cache or generated
	on-the-fly. Each partial hierarchy ends at a progressively deeper
	level. An interpolator interpolates a partial hierarchy layout by
	interpolating corresponding nodes in two partial hierarchies. A hierarchy
	manager manages partial hierarchies in response to requests from
	a viewer to move a camera to camera positions. Partial hierarchies
	are fetched from the cache or the interpolator. A display then displays
	display views of fetched partial hierarchies corresponding to the
	camera positions. During free-form navigation, a hierarchy manager
	determines and maintain an orientation based on at least one reference
	object. During zooming, an angular orientation is maintained through
	successive partial hierarchies. Mapping is also provided between
	a three-dimensional 3D partial hierarchy and a two-dimensional 2D
	overview of a complete hierarchy.},
  url = {http://www.freepatentsonline.com/6137499.html}
}

@MISC{Tesler1992,
  author = {Joel D. Tesler and Steven L. Strasnick},
  title = {{FSN}: The {3D} file system navigator},
  howpublished = {\url{ftp://ftp.sgi.com/sgi/fsn}},
  month = {April},
  year = {1992},
  note = {retrieved 28-APR-2010},
  organization = {Silicon Graphics, Inc.}
}

@MISC{Theisen2001,
  author = {Karen Theisen and Eugene Jhong},
  title = {Method of generating and navigating a {3-D} representation of a hierarchical
	data structure},
  howpublished = {United States Patent US 6259458 B1, filed Jan. 29, 1999, issued Jul.
	10},
  year = {2001},
  abstract = {A method of generating a graphical representation of a hierarchical
	data structure to on a display unit, the hierarchical data structure
	including a first node having at least one content item. A graphic
	tree representative of the hierarchical data structure is displayed
	on the display unit, the graphic tree including a first graphic representation
	of the first node. A second graphic representation, associated with
	the first graphic representation, that provides a representation
	of a content item (e.g., a file) is displayed on the display unit,
	the second graphic representation differing in appearance from the
	first graphic representation.},
  url = {http://www.freepatentsonline.com/6259458.html}
}

@MISC{Thorn2006,
  author = {Matthew Thorn and Donald Hoffman},
  title = {Treemap display with minimum cell size},
  howpublished = {United States Patent US 7027052 B2, filed Aug. 13, 2002, issued Apr.
	11},
  year = {2006},
  abstract = {A treemap with cells that have a minimum size so that large data sets
	can be clearly represented. A treemap that represents a plurality
	of data elements is generated, the treemap including a plurality
	of two-dimensional cells. Each cell represents a corresponding data
	element in the data set. The treemap includes a portion of a display
	screen assigned to a first cell so that the first cell has a size.
	A portion of the display screen is then assigned to a subsequent
	cell. The size of the first cell is adjusted in order to compensate
	for a size of the subsequent cell and to maintain the minimum cell
	size.},
  url = {http://www.freepatentsonline.com/7027052.html}
}

@ARTICLE{Tu2007,
  author = {Ying Tu and Han-Wei Shen},
  title = {Visualizing Changes of Hierarchical Data using Treemaps},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2007},
  volume = {13},
  pages = {1286--1293},
  number = {6},
  month = {November-December},
  abstract = {While the treemap is a popular method for visualizing hierarchical
	data, it is often difficult for users to track layout and attribute
	changes when the data evolve over time. When viewing the treemaps
	side by side or back and forth, there exist several problems that
	can prevent viewers from performing effective comparisons. Those
	problems include abrupt layout changes, a lack of prominent visual
	patterns to represent layouts, and a lack of direct contrast to highlight
	differences. In this paper, we present strategies to visualize changes
	of hierarchical data using treemaps. A new treemap layout algorithm
	is presented to reduce abrupt layout changes and produce consistent
	visual patterns. Techniques are proposed to effectively visualize
	the difference and contrast between two treemap snapshots in terms
	of the map items' colors, sizes, and positions. Experimental data
	show that our algorithm can achieve a good balance in maintaining
	a treemap's stability, continuity, readability, and average aspect
	ratio. A software tool is created to compare treemaps and generate
	the visualizations. User studies show that the users can better understand
	the changes in the hierarchy and layout, and more quickly notice
	the color and size differences using our method.},
  doi = {10.1109/TVCG.2007.70529}
}

@ARTICLE{Tuttle2010,
  author = {Claurissa Tuttle and Luis Gustavo Nonato and Claudio Silva},
  title = {{PedVis}: A Structured, Space-Efficient Technique for Pedigree Visualization},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2010},
  volume = {16},
  pages = {1063--1072},
  number = {6},
  month = {November-December},
  abstract = {Public genealogical databases are becoming increasingly populated
	with historical data and records of the current population's ancestors.
	As this increasing amount of available information is used to link
	individuals to their ancestors, the resulting trees become deeper
	and more dense, which justifies the need for using organized, space-efficient
	layouts to display the data. Existing layouts are often only able
	to show a small subset of the data at a time. As a result, it is
	easy to become lost when navigating through the data or to lose sight
	of the overall tree structure. On the contrary, leaving space for
	unknown ancestors allows one to better understand the tree's structure,
	but leaving this space becomes expensive and allows fewer generations
	to be displayed at a time. In this work, we propose that the H-tree
	based layout be used in genealogical software to display ancestral
	trees. We will show that this layout presents an increase in the
	number of displayable generations, provides a nicely arranged, symmetrical,
	intuitive and organized fractal structure, increases the user's ability
	to understand and navigate through the data, and accounts for the
	visualization requirements necessary for displaying such trees. Finally,
	user-study results indicate potential for user acceptance of the
	new layout.},
  doi = {10.1109/TVCG.2010.185}
}

@MISC{Tuttle2011,
  author = {Claurissa Tuttle and Claudio Silva},
  title = {Space efficient visualization of pedigree data},
  howpublished = {United States Patent Application US 2011/0072009 A1, filed Sep. 18,
	2009, published Mar. 24},
  year = {2011},
  abstract = {A method of visually representing pedigree data is provided. A root
	individual in a genealogical dataset is identified. A first parent
	and a second parent of the identified root individual are identified
	from the genealogical dataset. A third parent and a fourth parent
	of the identified first parent are identified from the genealogical
	dataset. A pedigree visualization relative to the identified root
	individual is presented which includes a root indicator, a first
	parent indicator, a second parent indicator, a third parent indicator,
	and a fourth parent indicator. The first parent indicator is presented
	in a first direction relative to the root indicator, the second parent
	indicator is presented in a second direction relative to the root
	indicator, wherein the second direction is opposite the first direction,
	the third parent indicator is presented in a third direction relative
	to the first parent indicator, wherein the third direction is perpendicular
	to the first direction, and the fourth parent indicator is presented
	in a fourth direction relative to the first parent indicator, wherein
	the fourth direction is opposite the third direction.},
  url = {http://www.freepatentsonline.com/y2011/0072009.html}
}

@MISC{Ukrop2011,
  author = {Lubo\v{s} Ukrop},
  title = {New approaches in graph visualization},
  howpublished = {Faculty of Informatics and Information Technologies, Slovak University
	of Technology, \url{http://vgg.fiit.stuba.sk/wordpress/2011-03/new-approaches-in-graph-visualization-lubos-ukrop/}},
  month = {March},
  year = {2011},
  note = {retrieved 18-JUN-2011}
}

@INPROCEEDINGS{Vernier2000,
  author = {Fr\'ed\'eric Vernier and Laurence Nigay},
  title = {Modifiable {Treemaps} Containing Variable-Shaped Units},
  booktitle = {Extended Abstracts of the IEEE Information Visualization 2000},
  year = {2000},
  abstract = {This paper presents a novel method, for the visualization of hierarchical
	information such as directory structures or family trees. Our technique
	is based on nested Treemaps and inherits the main property of the
	Treemaps: space-filling display of hierarchical information. For
	each node, our technique allocates a bounding box according to a
	ratio (height/width) that can be modified by the user according to
	her/his task. To do so, our algorithm does not apply the slice and
	dice (top-down) approach of standard Treemaps. Our technique is effective,
	easy to implement and has a wide applicability. To illustrate its
	application, we developed a system called PARENT which displays a
	directory tree. PARENT is tightly coupled with Microsoft Windows
	Explorer.},
  url = {http://iihm.imag.fr/publs/2000/Visu2K_Vernier.pdf}
}

@ARTICLE{Vliegen2006,
  author = {Roel Vliegen and Jarke J. van Wijk and Erik-Jan van der Linden},
  title = {Visualizing Business Data with Generalized Treemaps},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2006},
  volume = {12},
  pages = {789--796},
  number = {5},
  month = {September-October},
  abstract = {Business data is often presented using simple business graphics. These
	familiar visualizations are effective for providing overviews, but
	fall short for the presentation of large amounts of detailed information.
	Treemaps can provide such detail, but are often not easy to understand.
	We present how standard treemap algorithms can be adapted such that
	the results mimic familiar business graphics. Specifically, we present
	the use of different layout algorithms per level, a number of variations
	of the squarified algorithm, the use of variable borders, and the
	use of non-rectangular shapes. The combined use of these leads to
	histograms, pie charts and a variety of other styles.},
  doi = {10.1109/TVCG.2006.200}
}

@ARTICLE{Walker1990,
  author = {Walker,II, John Q.},
  title = {A node-positioning algorithm for general trees},
  journal = {Software -- Practice and Experience},
  year = {1990},
  volume = {20},
  pages = {685--705},
  number = {7},
  month = {July},
  abstract = {Drawing a tree consists of two stages: determining the position of
	each node, and actually rendering the individuals nodes and interconnecting
	branches. The algorithm described in this paper is concerned with
	the first stage: given a list of nodes, an indication of the hierarchical
	relationship among them, and their shape and size, where should each
	node be positioned for optimal aesthetic effect? This algorithm determines
	the positions of the nodes for any arbitrary general tree. It is
	the most desirable positioning with respect to certain widely-accepted
	heuristics. The positioning, specified in x, y co-ordinates, minimizes
	the width of the tree. In a general tree, there is no limit on the
	number of offspring per node; this contrasts with binary and ternary
	trees, for example, which are trees with a limit of two and three
	offspring per node. This algorithm operates in time O(N), where N
	is the number of nodes in the tree. Previously, most tree drawings
	have been positioned by the sure hand of a human graphic designer.
	Many computer-generated positionings have been either trivial or
	contained irregularities. Earlier work by Wetherell and Shannon1
	and Tilford,2 upon which this algorithm builds, failed to position
	the interior nodes of some trees correctly. The algorithm presented
	here correctly positions a tree's node using only two passes. It
	also handles several practical considerations: alternative orientations
	of the tree, variable node sizes and out-of-bounds conditions. Radack,
	also building on Tilford's work, has solved this same problem with
	a different algorithm which makes four passes.},
  doi = {10.1002/spe.4380200705}
}

@BOOK{Warnier1974,
  title = {Logical Construction of Programs},
  publisher = {Van Nostrand Reinhold Company},
  year = {1981},
  author = {Jean Dominique Warnier},
  isbn = {0442291930},
  url = {http://www.worldcat.org/oclc/2792121}
}

@BOOK{Warnier1981,
  title = {Logical Construction of Systems},
  publisher = {Van Nostrand Reinhold Company},
  year = {1981},
  author = {Jean Dominique Warnier},
  isbn = {0442225563},
  url = {http://www.worldcat.org/oclc/6555014}
}

@ARTICLE{Wattenberg2004,
  author = {Martin Wattenberg and Danyel Fisher},
  title = {Analyzing perceptual organization in information graphics},
  journal = {Information Visualization},
  year = {2004},
  volume = {3},
  pages = {123--133},
  number = {2},
  abstract = {We propose a new method for assessing the perceptual organization
	of information graphics, based on the premise that the visual structure
	of an image should match the structure of the data it is intended
	to convey. The core of our method is a new formal model of one type
	of perceptual structure, based on classical machine vision techniques
	for analyzing an image at multiple resolutions. The model takes as
	input an arbitrary grayscale image and returns a lattice structure
	describing the visual organization of the image. We show how this
	model captures several aspects of traditional design aesthetics,
	and we describe a software tool that implements the model to help
	designers analyze and refine visual displays. Our emphasis here is
	on demonstrating the model's potential as a design aid rather than
	as a description of human perception, but given its initial promise
	we propose a variety of ways in which the model could be extended
	and validated.},
  doi = {10.1057/palgrave.ivs.9500070}
}

@ARTICLE{Wattenberg2008,
  author = {Martin Wattenberg and Fernanda B. Viegas},
  title = {The {Word Tree}, an Interactive Visual Concordance},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2008},
  volume = {14},
  pages = {1221--1228},
  number = {6},
  month = {November-December},
  abstract = {We introduce the Word Tree, a new visualization and information-retrieval
	technique aimed at text documents. A Word Tree is a graphical version
	of the traditional "keyword-in-context" method, and enables rapid
	querying and exploration of bodies of text. In this paper we describe
	the design of the technique, along with some of the technical issues
	that arise in its implementation. In addition, we discuss the results
	of several months of public deployment of word trees on Many Eyes,
	which provides a window onto the ways in which users obtain value
	from the visualization.},
  doi = {10.1109/TVCG.2008.172}
}

@ARTICLE{Webber2006,
  author = {Richard Webber and Ric D. Herbert and Wei Jiang},
  title = {Space-filling Techniques in Visualizing Output from Computer Based
	Economic Models},
  journal = {Computing in Economics and Finance},
  year = {2006},
  volume = {2006},
  number = {67},
  month = {July},
  abstract = {One important factor concerning economic models is that frequently
	large amounts of data are produced. There is the research issue of
	how end-users (who may not be researchers or model developers) can
	be presented with this data so that maximum benefits can be attained
	from the data production. The usual approach with economic models
	is a series of tables or data series plots. In this paper we use
	space-filling information visualization techniques as an aid to user’s
	understanding of data from an economic model. Based upon evaluation
	of the effectiveness of existing treemap and sunburst techniques
	through user experimentation, we introduce two new space-filling
	visualization techniques. We also describe fisheye-lens techniques
	applicable to these new visualizations.},
  url = {http://ideas.repec.org/p/sce/scecfa/67.html}
}

@ARTICLE{Wetherell1979,
  author = {Charles Wetherell and Alfred Shannon},
  title = {Tidy Drawings of Trees},
  journal = {IEEE Transactions on Software Engineering},
  year = {1979},
  volume = {SE-5},
  pages = {514--520},
  number = {5},
  abstract = {Trees are extremely common data structures, both as internal objects
	and as models for program output. But it is unusual to see a program
	actually draw trees for visual inspection. Although part of the difficulty
	lies in programming graphics devices, most of the problem arises
	because naive algorithms to draw trees use too much drawing space
	and sophisticated algorithms are not obvious. We survey two naive
	tree drawers, formalize aesthetics for tidy trees, and descnbe two
	algorithms which draw tidy trees. One of the algorithms may be shown
	to require the minimum possible paper width. Along with the algorithms
	proper, we discuss the reasoning behind the algorithm development.},
  doi = {10.1109/TSE.1979.234212}
}

@MISC{Wetzel2003,
  author = {Kai Wetzel},
  title = {Pebbles -- using Circular Treemaps to visualize disk usage},
  howpublished = {\url{http://lip.sourceforge.net/ctreemap.html}},
  year = {2003},
  note = {retrieved 26-APR-2010},
  abstract = {During the 1990s Ben Shneiderman of the Human-Computer Interaction
	Laboritory (HCIL) of the University of Maryland invented Treemaps
	as a "compact visualization of directory tree structures". Treemaps
	involve "turning a tree into a planar space-filling" representation.
	Unlike other variations such as squarified treemaps, or cushion treemaps,
	circular treemaps as presented here could be considered an evolutionary
	dead-end (rejected early by Ben Shneiderman) but at least I think
	it's a pretty one.}
}

@ARTICLE{Wood2008,
  author = {Jo Wood and Jason Dykes},
  title = {Spatially Ordered Treemaps},
  journal = {IEEE Transactions on Visualization and Computer Graphics},
  year = {2008},
  volume = {14},
  pages = {1348--1355},
  number = {6},
  abstract = {Existing treemap layout algorithms suffer to some extent from poor
	or inconsistent mappings between data order and visual ordering in
	their representation, reducing their cognitive plausibility. While
	attempts have been made to quantify this mismatch, and algorithms
	proposed to minimize inconsistency, solutions provided tend to concentrate
	on one-dimensional ordering. We propose extensions to the existing
	squarified layout algorithm that exploit the two-dimensional arrangement
	of treemap nodes more effectively. Our proposed spatial squarified
	layout algorithm provides a more consistent arrangement of nodes
	while maintaining low aspect ratios. It is suitable for the arrangement
	of data with a geographic component and can be used to create tessellated
	car tograms for geovisualization. Locational consistency is measured
	and visualized and a number of layout algorithms are compared. CIELab
	color space and displacement vector overlays are used to assess and
	emphasize the spatial layout of treemap nodes. A case study involving
	locations of tagged photographs in the Flickr database is described.},
  doi = {10.1109/TVCG.2008.165}
}

@ARTICLE{Yang2003,
  author = {Jing Yang and Matthew O. Ward and Elke A. Rundensteiner and Anilkumar
	Patro},
  title = {{InterRing}: A visual interface for navigating and manipulating hierarchies},
  journal = {Information Visualization},
  year = {2003},
  volume = {2},
  pages = {16--30},
  number = {1},
  month = {March},
  abstract = {Radial, space-filling (RSF) techniques for hierarchy visualization
	have several advantages over traditional node–link diagrams, including
	the ability to use the display space efficiently while effectively
	conveying the hierarchy structure. Several RSF systems and tools
	have been developed to date, each with varying degrees of support
	for interactive operations such as selection and navigation. In this
	paper, we describe what we believe to be a complete set of desirable
	operations on hierarchical structures. We then present InterRing,
	an RSF hierarchy visualization system that supports a significantly
	more extensive set of these operations than prior systems. In particular,
	InterRing supports multifocus distortions, interactive hierarchy
	reconfiguration, and both semiautomated and manual selection. We
	show the power and utility of these and other operations, and describe
	our ongoing efforts to evaluate their effectiveness and usability.},
  doi = {10.1057/palgrave.ivs.9500035}
}

@INPROCEEDINGS{Zeckzer2010,
  author = {Dirk Zeckzer and Fang Chen and Hans Hagen},
  title = {Computing an Optimal Layout for Cone Trees},
  booktitle = {Scientific Visualization: Advanced Concepts},
  year = {2010},
  editor = {Hans Hagen},
  pages = {11--29},
  abstract = {Many visual representations for trees have been developed in information
	and software visualization. One of them are cone trees, a well-known
	three-dimensional representation for trees. This paper is based on
	an approach for constructing cone trees bottom-up. For this approach,
	an optimal layout for these trees is given together with a proof
	that based on the assumptions, there can be no better layouts. This
	comprises special cases, an optimal constant for the general case,
	and a post-processing step improving the layout.},
  doi = {10.4230/DFU.SciViz.2010.11}
}

@PROCEEDINGS{IHM2007,
  title = {International Conference on Association Francophone d'Interaction
	Homme-Machine, 13-15 November 2007},
  year = {2007},
  abbrev = {IHM},
  booktitle = {IHM'07: } # PROC # {International Conference on Association Francophone
	d'Interaction Homme-Machine},
  editor = {Carlos Agon and Olivier Delerue},
  publisher = {ACM Press},
  location = {Paris, France},
  isbn = {9781595937919},
}

@PROCEEDINGS{IHM2007,
  title = {International Conference on Association Francophone d'Interaction
	Homme-Machine, 13-15 November 2007},
  year = {2007},
  abbrev = {IHM},
  booktitle = {IHM'07: } # PROC # {International Conference on Association Francophone
	d'Interaction Homme-Machine},
  editor = {Carlos Agon and Olivier Delerue},
  publisher = {ACM Press},
  location = {Paris, France},
  isbn = {9781595937919},
}

@PROCEEDINGS{INFOVIS2001,
  title = {IEEE Symposium on Information Visualization, 22-23 October 2001},
  year = {2001},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'01: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Keith Andrews and Steven Roth and Pak Chung Wong},
  publisher = {IEEE Computer Society},
  location = {San Diego, CA, USA},
  isbn = {0769513425},
}

@PROCEEDINGS{INFOVIS2001,
  title = {IEEE Symposium on Information Visualization, 22-23 October 2001},
  year = {2001},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'01: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Keith Andrews and Steven Roth and Pak Chung Wong},
  publisher = {IEEE Computer Society},
  location = {San Diego, CA, USA},
  isbn = {0769513425},
}

@PROCEEDINGS{INFOVIS2001,
  title = {IEEE Symposium on Information Visualization, 22-23 October 2001},
  year = {2001},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'01: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Keith Andrews and Steven Roth and Pak Chung Wong},
  publisher = {IEEE Computer Society},
  location = {San Diego, CA, USA},
  isbn = {0769513425},
}

@PROCEEDINGS{ISVD2009,
  title = {International Symposium on Voronoi Diagrams, 23-26 June 2009},
  year = {2009},
  abbrev = {ISVD},
  booktitle = {ISVD'09: } # PROC # {International Symposium on Voronoi Diagrams},
  editor = {Fran\c{c}ois Anton},
  publisher = {IEEE Computer Society},
  location = {Copenhagen, Denmark},
  isbn = {9780769537818},
}

@PROCEEDINGS{ISAAC2011,
  title = {International Symposium on Algorithms and Computations, 5-8 December
	2011},
  year = {2011},
  abbrev = {ISAAC},
  booktitle = {ISAAC'11: } # PROC # {International Symposium on Algorithms and Computations},
  editor = {Takao Asano and Shin-ichi Nakano and Yoshio Okamoto and Osamu Watanabe},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Yokohama, Japan},
  isbn = {9783642255908},
  doi = {10.1007/978-3-642-25591-5}
}

@PROCEEDINGS{IV2006,
  title = {International Conference on Information Visualisation, 5-7 July 2006},
  year = {2006},
  abbrev = {IV},
  booktitle = {IV'06: } # PROC # {International Conference on Information Visualisation},
  editor = {Ebad Banissi and Remo Aslak Burkhard and Anna Ursyn and Jian J. Zhang
	and Mark Bannatyne and Carsten Maple and Andrew J. Cowell and Gui
	Yun Tian and Ming Hou},
  publisher = {IEEE Computer Society},
  location = {London, UK},
  isbn = {0769526020},
}

@PROCEEDINGS{CGIV2007,
  title = {Computer Graphics, Imaging and Visualisation, 14-17 August 2007},
  year = {2007},
  abbrev = {CGIV},
  booktitle = {CGIV'07: } # PROC # {Computer Graphics, Imaging and Visualisation},
  editor = {Ebad Banissi and Muhammad Sarfraz and Natasha Dejdumrong},
  publisher = {IEEE Computer Society},
  location = {Bangkok, Thailand},
  isbn = {0769529283},
}

@PROCEEDINGS{IV2008,
  title = {International Conference on Information Visualisation, 9-11 July
	2008},
  year = {2008},
  abbrev = {IV},
  booktitle = {IV'08: } # PROC # {International Conference on Information Visualisation},
  editor = {Ebad Banissi and Liz Stuart and Mikael Jern and Gennady Andrienko
	and Francis T. Marchese and Nasrullah Memon and Reda Alhajj and Theodor
	G. Wyeld and Remo Aslak Burkhard and Georges Grinstein and Dennis
	Groth and Anna Ursyn and Carsten Maple and Anthony Faiola and Brock
	Craft},
  publisher = {IEEE Computer Society},
  location = {London, UK},
  isbn = {9780769532684},
}

@PROCEEDINGS{IV2009,
  title = {International Conference on Information Visualisation, 15-17 July
	2009},
  year = {2009},
  abbrev = {IV},
  booktitle = {IV'09: } # PROC # {International Conference on Information Visualisation},
  editor = {Ebad Banissi and Liz Stuart and Theodor G. Wyeld and Mikael Jern
	and Gennady Andrienko and Nasrullah Memon and Reda Alhajj and Remo
	Aslak Burkhard and Georges Grinstein and Dennis Groth and Anna Ursyn
	and Jimmy Johansson and Camilla Forsell and Urska Cvek and Marjan
	Trutschi and Francis T. Marchese and Carsten Maple and Andrew J.
	Cowell and Andrew Vande Moere},
  publisher = {IEEE Computer Society},
  location = {Barcelona, Spain},
  isbn = {9780769537337},
}

@PROCEEDINGS{IV2009,
  title = {International Conference on Information Visualisation, 15-17 July
	2009},
  year = {2009},
  abbrev = {IV},
  booktitle = {IV'09: } # PROC # {International Conference on Information Visualisation},
  editor = {Ebad Banissi and Liz Stuart and Theodor G. Wyeld and Mikael Jern
	and Gennady Andrienko and Nasrullah Memon and Reda Alhajj and Remo
	Aslak Burkhard and Georges Grinstein and Dennis Groth and Anna Ursyn
	and Jimmy Johansson and Camilla Forsell and Urska Cvek and Marjan
	Trutschi and Francis T. Marchese and Carsten Maple and Andrew J.
	Cowell and Andrew Vande Moere},
  publisher = {IEEE Computer Society},
  location = {Barcelona, Spain},
  isbn = {9780769537337},
}

@PROCEEDINGS{INTERACT2007,
  title = {IFIP TC13 Conference on Human-Computer Interaction, 10-14 September
	2007},
  year = {2007},
  abbrev = {INTERACT},
  booktitle = {INTERACT'07: } # PROC # {IFIP TC13 Conference on Human-Computer Interaction,
	Part II},
  editor = {C\'ecilia Baranauskas and Philippe Palanque and Julio Abascal and
	Simone Diniz Junqueira Barbosa},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Rio de Janeiro, Brazil},
  isbn = {9783540747994},
  doi = {10.1007/978-3-540-74800-7}
}

@PROCEEDINGS{GI2008,
  title = {Graphics Interface, 28-30 May 2008},
  year = {2008},
  abbrev = {GI},
  booktitle = {GI'08: } # PROC # {Graphics Interface Conference},
  editor = {Lyn Bartram and Chris Shaw},
  publisher = {Canadian Information Processing Society},
  location = {Windsor, Ontario, Canada},
  isbn = {9781568814230},
}

@PROCEEDINGS{CHI1992,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 03-07 May
	1992},
  year = {1992},
  abbrev = {CHI},
  booktitle = {CHI'92: } # PROC # {SIGCHI conference on Human Factors in Computing
	Systems},
  editor = {Penny Bauersfeld and John Bennett and Gene Lynch},
  publisher = {ACM Press},
  location = {Monterey, CA, USA},
  isbn = {0897915135},
}

@PROCEEDINGS{ISVC2010,
  title = {International Symposium on Visual Computing, 29 November - 1 December
	2010},
  year = {2010},
  abbrev = {ISVC},
  booktitle = {Advances in Visual Computing: } # PROC # {International Symposium
	on Visual Computing 2010},
  editor = {George Bebis and Richard Boyle and Bahram Parvin and Darko Koracin
	and Ronald Chung and Riad Hammoud and Muhammad Hussain and Tan Kar-Han
	and Roger Crawfis and Daniel Thalmann and David kao and Lisa Avila},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Las Vegas, NV, USA},
  isbn = {3642172881},
  doi = {10.1007/978-3-642-17289-2}
}

@PROCEEDINGS{ISVC2010,
  title = {International Symposium on Visual Computing, 29 November - 1 December
	2010},
  year = {2010},
  abbrev = {ISVC},
  booktitle = {Advances in Visual Computing: } # PROC # {International Symposium
	on Visual Computing 2010},
  editor = {George Bebis and Richard Boyle and Bahram Parvin and Darko Koracin
	and Ronald Chung and Riad Hammoud and Muhammad Hussain and Tan Kar-Han
	and Roger Crawfis and Daniel Thalmann and David kao and Lisa Avila},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Las Vegas, NV, USA},
  isbn = {3642172881},
  doi = {10.1007/978-3-642-17289-2}
}

@PROCEEDINGS{ISVC2011,
  title = {International Symposium on Visual Computing, 26-28 September2011},
  year = {2011},
  abbrev = {ISVC},
  booktitle = {Advances in Visual Computing: } # PROC # {International Symposium
	on Visual Computing 2011},
  editor = {George Bebis and Richard Boyle and Bahram Parvin and Darko Koracin
	and Song Wang and Kim Kyungnam and Bedrich Benes and Kenneth Moreland
	and Christoph Borst and Stephen DiVerdi and Chiang Yi-Jen and Jiang
	Ming},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Las Vegas, NV, USA},
  isbn = {9783642240270},
  doi = {10.1007/978-3-642-24028-7}
}

@PROCEEDINGS{EUSW2005,
  title = {ISWC Workshop on End User Semantic Web Interaction, 7 November 2005},
  year = {2005},
  abbrev = {EUSW},
  booktitle = PROC # {ISWC Workshop on End User Semantic Web Interaction 2005},
  editor = {Abraham Bernstein and Ion Androutsopoulos and Duane Degler and Brian
	McBride},
  publisher = {CEUR Workshop Proceedings},
  location = {Galway, Ireland},
  url = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-172/}
}

@PROCEEDINGS{IS2007,
  title = {International Multiconference Information Society, 8-12 October 2007},
  year = {2007},
  abbrev = {IS},
  booktitle = {IS'07: } # PROC # {International Multiconference Information Society},
  editor = {Marko Bohanec and Matja\v{z} Gams and Vladislav Rajkovi\v{c} and
	Tanja Urban\v{c}i\v{c} and Mojca Bernik and Dunja Mladeni\'c and
	Marko Grobelnik and Marjan Heri\v{c}ko and Urban Korde\v{s} and Olga
	Marki\v{c}},
  location = {Ljubljana, Slovenia},
  isbn = {9789616303941},
  url = {http://is.ijs.si/is/is2007/Proceedings/Proceedings.html}
}

@PROCEEDINGS{AVI2008,
  title = {Working Conference on Advanced Visual Interfaces, 28-30 May 2008},
  year = {2008},
  abbrev = {AVI},
  booktitle = {AVI'08: } # PROC # {Working Conference on Advanced Visual Interfaces},
  editor = {Paolo Bottoni and Stefano Levialdi},
  publisher = {ACM Press},
  location = {Naples, Italy},
  isbn = {9781605581415},
}

@PROCEEDINGS{GD2010,
  title = {International Symposium on Graph Drawing, 21-24 September 2010},
  year = {2010},
  abbrev = {GD},
  booktitle = {GD'10: } # PROC # {International Symposium on Graph Drawing},
  editor = {Ulrik Brandes and Sabine Cornelsen},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Konstanz, Germany},
  isbn = {9783642184680},
  doi = {10.1007/978-3-642-18469-7}
}

@PROCEEDINGS{GD2010,
  title = {International Symposium on Graph Drawing, 21-24 September 2010},
  year = {2010},
  abbrev = {GD},
  booktitle = {GD'10: } # PROC # {International Symposium on Graph Drawing},
  editor = {Ulrik Brandes and Sabine Cornelsen},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Konstanz, Germany},
  isbn = {9783642184680},
  doi = {10.1007/978-3-642-18469-7}
}

@PROCEEDINGS{EUROVIS2005,
  title = {Joint Eurographics - IEEE VGTC Symposium on Visualization, 1-3 June
	2005},
  year = {2005},
  abbrev = {EUROVIS},
  booktitle = {EuroVis'05: } # PROC # {Joint Eurographics - IEEE VGTC Symposium
	on Visualization},
  editor = {Ken Brodlie and David Duke and Kenneth I. Joy},
  publisher = {Eurographics Association},
  location = {Leeds, UK},
  isbn = {3905673193},
}

@PROCEEDINGS{EUROVIS2005,
  title = {Joint Eurographics - IEEE VGTC Symposium on Visualization, 1-3 June
	2005},
  year = {2005},
  abbrev = {EUROVIS},
  booktitle = {EuroVis'05: } # PROC # {Joint Eurographics - IEEE VGTC Symposium
	on Visualization},
  editor = {Ken Brodlie and David Duke and Kenneth I. Joy},
  publisher = {Eurographics Association},
  location = {Leeds, UK},
  isbn = {3905673193},
}

@PROCEEDINGS{HCI2006,
  title = {Human Computer Interaction, 11-15 September 2006},
  year = {2006},
  abbrev = {HCI},
  booktitle = {People and Computers XX -- Engage: } # PROC # {Human Computer Interaction
	2006},
  editor = {Nick Bryan-Kinns and Ann Blandford and Paul Curzon and Laurence Nigay},
  publisher = {Springer},
  location = {London, UK},
  isbn = {9781846285882},
  doi = {10.1007/978-1-84628-664-3}
}

@PROCEEDINGS{ICCS2004,
  title = {International Conference on Computational Science, 6-9 June 2004},
  year = {2004},
  abbrev = {ICCS},
  booktitle = {ICCS'04: } # PROC # {International Conference on Computational Science},
  editor = {Marian Bubak and Geert Dick van Albada and Peter M.A. Sloot and Jack
	J. Dongarra},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Krakow, Poland},
  isbn = {3540221166},
  doi = {10.1007/b97989}
}

@PROCEEDINGS{AVI1992,
  title = {Workshop on Advanced Visual Interfaces, 27-29 May 1992},
  year = {1992},
  abbrev = {AVI},
  booktitle = {AVI'92: } # PROC # {Workshop on Advanced Visual Interfaces},
  editor = {Tiziana Catarci and Maria Francesca Costabile and Stefano Levialdi},
  publisher = {World Scientific Publishing},
  location = {Rome, Italy},
  isbn = {9810211236},
}

@PROCEEDINGS{AVI2006,
  title = {Working Conference on Advanced Visual Interfaces, 23-26 May 2006},
  year = {2006},
  abbrev = {AVI},
  booktitle = {AVI'06: } # PROC # {Working Conference on Advanced Visual Interfaces},
  editor = {Augusto Celentano and Piero Mussio},
  publisher = {ACM Press},
  location = {Venezia, Italy},
  isbn = {1595933530},
}

@PROCEEDINGS{BIBMW2009,
  title = {IEEE International Conference on Bioinformatics and Biomedicine Workshops,
	1-4 November 2009},
  year = {2009},
  abbrev = {BIBMW},
  booktitle = {BIBMW'09: } # PROC # {IEEE International Conference on Bioinformatics
	and Biomedicine Workshops},
  editor = {Jake Chen and Xin Chen and John Ely and Dilek Hakkani-Tr and Jing
	He and Hui-Huang Hsu and Li Liao and Chunmei Liu and Mihai Pop and
	Shoba Ranganathan and Chandan K. Reddy and Jianhua Ruan and Yinglei
	Song and Vincent S. Tseng and Lyle Ungar and Di Wu and Zhijun Wu
	and Kai Xu and Hong Yu and Alexander Zelikovsky},
  publisher = {IEEE Computer Society},
  location = {Washington DC, USA},
  isbn = {9781424451210},
}

@PROCEEDINGS{ICAT2006,
  title = {International Conference on Artificial Reality and Telexistence,
	29 November-02 December 2006},
  year = {2006},
  abbrev = {ICAT},
  booktitle = {ICAT'06: } # PROC # {International Conference on Artificial Reality
	and Telexistence},
  editor = {Qingzhang Chen and Ronghua Liang and Zhigeng Pan},
  publisher = {IEEE Computer Society},
  location = {Hangzhou, China},
  isbn = {076952754X},
}

@PROCEEDINGS{CHI2003,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 5-10 April
	2003},
  year = {2003},
  abbrev = {CHI},
  booktitle = {CHI'03: } # PROC # {International Conference on Human Factors in
	Computing Systems},
  editor = {Gilbert Cockton and Panu Korhonen},
  publisher = {ACM Press},
  location = {Ft. Lauderdale, FL, USA},
  isbn = {1581136307},
}

@PROCEEDINGS{AVI2004,
  title = {Working Conference on Advanced Visual Interfaces, 25-28 May 2004},
  year = {2004},
  abbrev = {AVI},
  booktitle = {AVI'04: } # PROC # {Working Conference on Advanced Visual Interfaces},
  editor = {Maria Francesca Costabile},
  publisher = {ACM Press},
  location = {Gallipoli (Lecce), Italy},
  isbn = {1581138679},
}

@PROCEEDINGS{AVI2004,
  title = {Working Conference on Advanced Visual Interfaces, 25-28 May 2004},
  year = {2004},
  abbrev = {AVI},
  booktitle = {AVI'04: } # PROC # {Working Conference on Advanced Visual Interfaces},
  editor = {Maria Francesca Costabile},
  publisher = {ACM Press},
  location = {Gallipoli (Lecce), Italy},
  isbn = {1581138679},
}

@PROCEEDINGS{INTERACT2005,
  title = {IFIP TC13 Conference on Human-Computer Interaction, 12-16 September
	2005},
  year = {2005},
  abbrev = {INTERACT},
  booktitle = {INTERACT'05: } # PROC # {IFIP TC13 Conference on Human-Computer Interaction},
  editor = {Maria Francesca Costabile and Fabio Patern\'o},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Rome, Italy},
  isbn = {3540289437},
  doi = {10.1007/11555261}
}

@PROCEEDINGS{ISWC2006,
  title = {International Semantic Web Conference, 5-9 November 2006},
  year = {2006},
  abbrev = {ISWC},
  booktitle = {ISWC'06: } # PROC # {International Semantic Web Conference},
  editor = {Isabel Cruz and Stefan Decker and Dean Allemang and Chris Preist
	and Daniel Schwabe and Peter Mika and Mike Uschold and Lora Aroyo},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Athens, GA, USA},
  isbn = {9783540490296},
  doi = {10.1007/11926078}
}

@PROCEEDINGS{WADS2011,
  title = {International Symposium on Algorithms and Data Structures, 15-17
	August 2011},
  year = {2011},
  abbrev = {WADS},
  booktitle = {WADS'11: } # PROC # {International Symposium on Algorithms and Data
	Structures},
  editor = {Frank Dehne and John Iacono and J\"org-R\"udiger Sack},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Brooklyn, NY, USA},
  isbn = {9783642222993},
  doi = {10.1007/978-3-642-22300-6}
}

@PROCEEDINGS{ISAAC2005,
  title = {International Symposium on Algorithms and Computations, 19-21 December
	2005},
  year = {2005},
  abbrev = {ISAAC},
  booktitle = {ISAAC'05: } # PROC # {International Symposium on Algorithms and Computations},
  editor = {Xiaotie Deng and Dingzhu Du},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Sanya, Hainan, China},
  isbn = {9783540309352},
  doi = {10.1007/11602613}
}

@PROCEEDINGS{GD1997,
  title = {International Symposium on Graph Drawing, 18-20 September 1997},
  year = {1997},
  abbrev = {GD},
  booktitle = {GD'97: } # PROC # {International Symposium on Graph Drawing},
  editor = {Giuseppe DiBattista},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Rome, Italy},
  isbn = {3540639381},
  doi = {10.1007/3-540-63938-1}
}

@PROCEEDINGS{INFOVIS1997,
  title = {IEEE Symposium on Information Visualization, 18-25 October 1997},
  year = {1997},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'97: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {John Dill and Nahum D. Gershon},
  publisher = {IEEE Computer Society},
  location = {Phoenix, AZ, USA},
  isbn = {0818681896},
}

@PROCEEDINGS{ISAAC1994,
  title = {International Symposium on Algorithms and Computations, 25-27 August
	1994},
  year = {1994},
  abbrev = {ISAAC},
  booktitle = {ISAAC'94: } # PROC # {International Symposium on Algorithms and Computations},
  editor = {Ding-Zhu Du and Xiang-Sun Zhang},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Beijing, China},
  isbn = {3540583254},
  doi = {10.1007/3-540-58325-4}
}

@PROCEEDINGS{PACIFICVIS2009,
  title = {IEEE Pacific Visualization Symposium, 20-23 April 2009},
  year = {2009},
  abbrev = {PACIFICVIS},
  booktitle = {PacificVis'09: } # PROC # {IEEE Pacific Visualization Symposium},
  editor = {Peter Eades and Thomas Ertl and Han-Wei Shen},
  publisher = {IEEE Computer Society},
  location = {Beijing, China},
  isbn = {9781424444055},
}

@PROCEEDINGS{PACIFICVIS2009,
  title = {IEEE Pacific Visualization Symposium, 20-23 April 2009},
  year = {2009},
  abbrev = {PACIFICVIS},
  booktitle = {PacificVis'09: } # PROC # {IEEE Pacific Visualization Symposium},
  editor = {Peter Eades and Thomas Ertl and Han-Wei Shen},
  publisher = {IEEE Computer Society},
  location = {Beijing, China},
  isbn = {9781424444055},
}

@PROCEEDINGS{NPIVM1997,
  title = {Workshop on New Paradigms in Information Visualization and Manipulation,
	10-14 November 1997},
  year = {1997},
  abbrev = {NPIVM},
  booktitle = {NPIVM'97: } # PROC # {Workshop on New Paradigms in Information Visualization
	and Manipulation},
  editor = {David S. Ebert and Charles K. Nicholas},
  publisher = {ACM Press},
  location = {Las Vegas, NV, USA},
  isbn = {1581130511},
}

@PROCEEDINGS{NPIV1999,
  title = {Workshop on New Paradigms in Information Visualization and Manipulation,
	02-06 November 1999},
  year = {1999},
  abbrev = {NPIV},
  booktitle = {NPIV'99: } # PROC # {Workshop on New Paradigms in Information Visualization
	and Manipulation},
  editor = {David S. Ebert and Christopher D. Shaw},
  publisher = {ACM Press},
  location = {Kansas City, MO, United States},
}

@PROCEEDINGS{ASE2005,
  title = {IEEE/ACM international Conference on Automated Software Engineering,
	07-11 November 2005},
  year = {2005},
  abbrev = {ASE},
  booktitle = {ASE'05: } # PROC # {IEEE/ACM international Conference on Automated
	Software Engineering},
  editor = {Tom Ellman and Andrea Zisman},
  publisher = {ACM Press},
  location = {Long Beach, CA, USA},
  isbn = {1581139934},
}

@PROCEEDINGS{ENC2005,
  title = {Mexican International Conference on Computer Science, 26-30 September
	2005},
  year = {2005},
  abbrev = {ENC},
  booktitle = {ENV'05: } # PROC # {Mexican International Conference on Computer
	Science},
  editor = {Vladimir Estivill-Castro and J. Alfredo Sanchez},
  publisher = {IEEE Computer Society},
  location = {Puebla, Mexico},
  isbn = {0769524540},
}

@PROCEEDINGS{PACIFICVIS2008,
  title = {IEEE Pacific Visualization Symposium, 5-7 March 2008},
  year = {2008},
  abbrev = {PACIFICVIS},
  booktitle = {PacificVis'08: } # PROC # {IEEE Pacific Visualization Symposium},
  editor = {Issei Fujishiro and Hua Li and Kwan-Liu Ma},
  publisher = {IEEE Computer Society},
  location = {Kyoto, Japan},
  isbn = {9781424419661},
}

@PROCEEDINGS{PACIFICVIS2008,
  title = {IEEE Pacific Visualization Symposium, 5-7 March 2008},
  year = {2008},
  abbrev = {PACIFICVIS},
  booktitle = {PacificVis'08: } # PROC # {IEEE Pacific Visualization Symposium},
  editor = {Issei Fujishiro and Hua Li and Kwan-Liu Ma},
  publisher = {IEEE Computer Society},
  location = {Kyoto, Japan},
  isbn = {9781424419661},
}

@PROCEEDINGS{INFOVIS1995,
  title = {IEEE Symposium on Information Visualization, 30-31 October 1995},
  year = {1995},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'95: } # PROC # {IEEE Symposium On Information Visualization},
  editor = {Nahum D. Gershon and Stephen G. Eick},
  publisher = {IEEE Computer Society},
  location = {Atlanta, Georgia, USA},
  isbn = {0818672013},
}

@PROCEEDINGS{AVI2000,
  title = {Working Conference on Advanced Visual Interfaces, 23-26 May 2000},
  year = {2000},
  abbrev = {AVI},
  booktitle = {AVI'00: } # PROC # {Working Conference on Advanced Visual Interfaces},
  editor = {Vito Di Ges\'u and Stefano Levialdi and Laura Tarantino},
  publisher = {ACM Press},
  location = {Palermo, Italy},
  isbn = {1581132522},
}

@PROCEEDINGS{AVI2000,
  title = {Working Conference on Advanced Visual Interfaces, 23-26 May 2000},
  year = {2000},
  abbrev = {AVI},
  booktitle = {AVI'00: } # PROC # {Working Conference on Advanced Visual Interfaces},
  editor = {Vito Di Ges\'u and Stefano Levialdi and Laura Tarantino},
  publisher = {ACM Press},
  location = {Palermo, Italy},
  isbn = {1581132522},
}

@PROCEEDINGS{DIAGRAMS2010,
  title = {International Conference on the Theory and Application of Diagrams,
	9-11 August 2010},
  year = {2010},
  abbrev = {DIAGRAMS},
  booktitle = {Diagrammatic Representation and Inference: } # PROC # {International
	Conference Diagrams 2010},
  editor = {Ashok K. Goel and Mateja Jamnik and N. Hari Narayanan},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Portland, OR, USA},
  isbn = {364214599X},
  doi = {10.1007/978-3-642-14600-8}
}

@PROCEEDINGS{GD2002,
  title = {International Symposium on Graph Drawing, 26-28 August 2002},
  year = {2002},
  abbrev = {GD},
  booktitle = {GD'02: } # PROC # {International Symposium on Graph Drawing},
  editor = {Michael T. Goodrich and Stephen G. Kobourov},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Irvine, CA, USA},
  isbn = {9783540001584},
  doi = {10.1007/3-540-36151-0}
}

@PROCEEDINGS{GD2002,
  title = {International Symposium on Graph Drawing, 26-28 August 2002},
  year = {2002},
  abbrev = {GD},
  booktitle = {GD'02: } # PROC # {International Symposium on Graph Drawing},
  editor = {Michael T. Goodrich and Stephen G. Kobourov},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Irvine, CA, USA},
  isbn = {9783540001584},
  doi = {10.1007/3-540-36151-0}
}

@PROCEEDINGS{VISSYM1999,
  title = {Joint Eurographics - IEEE TCVG Symposium on Visualization, 26-28
	May 1999},
  year = {1999},
  abbrev = {VISSYM},
  booktitle = {VisSym'99: } # PROC # {Joint Eurographics - IEEE TCVG Symposium on
	Visualization},
  editor = {Eduard Gr\"oller and Helwig L\"offelmann and William Ribarsky},
  publisher = {Eurographics Association},
  location = {Vienna, Austria},
  url = {http://diglib.eg.org/EG/DL/WS/VisSym99}
}

@PROCEEDINGS{CHI2006,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 22-27 April
	2006},
  year = {2006},
  abbrev = {CHI},
  booktitle = {CHI'06: } # PROC # {International Conference on Human Factors in
	Computing Systems},
  editor = {Rebecca Grinter and Thomas Rodden and Paul Aoki and Ed Cutrell and
	Robin Jeffries and Gary Olson},
  publisher = {ACM Press},
  location = {Montreal, Quebec, Canada},
  isbn = {1595933727},
}

@PROCEEDINGS{INTERACT2009,
  title = {IFIP TC13 Conference on Human-Computer Interaction, 24-28 August
	2009},
  year = {2009},
  abbrev = {INTERACT},
  booktitle = {INTERACT'09: } # PROC # {IFIP TC13 Conference on Human-Computer Interaction,
	Part II},
  editor = {Tom Gross and Jan Gulliksen and Paula Kotz\'{e} and Lars Oestreicher
	and Philippe Palanque and Raquel Oliveira Prates and Marco Winckler},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Uppsala, Sweden},
  isbn = {3642036570},
  doi = {10.1007/978-3-642-03658-3}
}

@PROCEEDINGS{VL1995,
  title = {IEEE Symposium on Visual Languages, 05-09 September 1995},
  year = {1995},
  abbrev = {VL},
  booktitle = {VL'95: } # PROC # {IEEE Symposium on Visual Languages},
  editor = {Volker Haarslev},
  publisher = {IEEE Computer Society},
  location = {Darmstadt, Germany},
  isbn = {0818670452},
}

@PROCEEDINGS{SE2004,
  title = {IASTED International Conference on Software Engineering, 17-19 February
	2004},
  year = {2004},
  abbrev = {SE},
  booktitle = {SE'04: } # PROC # {IASTED International Conference on Software Engineering},
  editor = {M. H. Hamza},
  publisher = {ACTA Press},
  location = {Innsbruck, Austria},
  isbn = {0889863814}
}

@PROCEEDINGS{HCII2003,
  title = {HCI International, 22-27 June 2003},
  year = {2003},
  abbrev = {HCII},
  booktitle = {Human-Centered Computing: Cognitive, Social, and Ergonomic Aspects:
	} # PROC # {HCI International},
  editor = {Don Harris and Vincent Duffy and Michael Smith and Constantine Stephanidis},
  publisher = {Lawrence Erlbaum Associates},
  location = {Heraclion, Greece},
  isbn = {0805849327},
}

@PROCEEDINGS{GD2005,
  title = {International Symposium on Graph Drawing, 12-14 September 2005},
  year = {2005},
  abbrev = {GD},
  booktitle = {GD'05: } # PROC # {International Symposium on Graph Drawing},
  editor = {Patrick Healy and Nikola S. Nikolov},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Limerick, Ireland},
  isbn = {9783540314257},
  doi = {10.1007/11618058}
}

@PROCEEDINGS{OWLED2009,
  title = {International Workshop on OWL: Experiences and Directions, 23-24
	October 2009},
  year = {2009},
  abbrev = {OWLED},
  booktitle = {OWLED'09: } # PROC # {International Workshop on OWL: Experiences
	and Directions},
  editor = {Rinke Hoekstra and Peter F. Patel-Schneider},
  publisher = {CEUR Workshop Proceedings},
  location = {Chantilly, VA, USA},
  url = {http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-529/}
}

@PROCEEDINGS{APVIS2007,
  title = {Asia Pacific Symposium on Information Visualization, 5-7 February
	2007},
  year = {2007},
  abbrev = {APVIS},
  booktitle = {APVIS'07: } # PROC # {Asia Pacific Symposium on Information Visualization},
  editor = {Seok-Hee Hong and Kwan-Liu Ma},
  publisher = {IEEE Computer Society},
  series = {Conference in Research and Practice in Information Technology},
  location = {Sydney, Australia},
  isbn = {1424408083},
}

@PROCEEDINGS{HCII2009,
  title = {HCI International, 19-24 July 2009},
  year = {2009},
  abbrev = {HCII},
  booktitle = {Human-Computer Interaction. Novel Interaction Methods and Techniques:
	} # PROC # {HCI International},
  editor = {Julie A. Jacko},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {San Diego, CA, USA},
  isbn = {9783642025761},
  doi = {10.1007/978-3-642-02577-8}
}

@PROCEEDINGS{HCII2007,
  title = {HCI International, 22-27 July 2007},
  year = {2007},
  abbrev = {HCII},
  booktitle = {Human-Computer Interaction. Interaction Platforms and Techniques:
	} # PROC # {HCI International},
  editor = {Julie A. Jacko},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Beijing, China},
  isbn = {3540731067},
  doi = {10.1007/978-3-540-73107-8}
}

@PROCEEDINGS{WSCGposter2006,
  title = {International Conference in Central Europe on Computer Graphics,
	Visualization and Computer Vision, 31 January-2 February 2006},
  year = {2006},
  abbrev = {WSCGposter},
  booktitle = {WSCG'06: } # PROC # {International Conference in Central Europe on
	Computer Graphics, Visualization and Computer Vision},
  editor = {Joaquim Jorge and Vaclav Skala},
  publisher = {University of West Bohemia},
  location = {Plzen, Czech Republic},
  isbn = {8086943046},
  url = {http://wscg.zcu.cz/WSCG2006/Papers_2006/Poster/!WSCG2006_Poster_Proceedings_Final.pdf}
}

@PROCEEDINGS{SMC2002,
  title = {IEEE International Conference on Systems, Man and Cybernetics, 6-9
	October 2002},
  year = {2002},
  abbrev = {SMC},
  booktitle = {SMC'02: } # PROC # {IEEE International Conference on Systems, Man
	and Cybernetics},
  editor = {Abdelkader El Kamel and Khaled Mellouli and Pierre Borne},
  publisher = {IEEE Computer Society},
  location = {Yasmine Hammamet, Tunisia},
  isbn = {0780374371},
}

@PROCEEDINGS{Bridges2009,
  title = {Bridges Conference on Mathematics, Music, Art, Architecture, Culture,
	26-29 July 2009},
  year = {2009},
  abbrev = {Bridges},
  booktitle = {Bridges'09: } # PROC # {Bridges Conference on Mathematics, Music,
	Art, Architecture, Culture},
  editor = {Craig S. Kaplan and Reza Sarhangi},
  publisher = {Tarquin Books},
  location = {Banff, Canada},
  isbn = {9780966520194},
  url = {http://bridgesmathart.org/past-conferences/bridges-2009/2009-proceedings/}
}

@PROCEEDINGS{CHI1998,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 18-23 April
	1998},
  year = {1998},
  abbrev = {CHI},
  booktitle = {CHI'98: } # PROC # {SIGCHI conference on Human Factors in Computing
	Systems},
  editor = {Clare-Marie Karat and Arnold Lund and Jo\"elle Coutaz and John Karat},
  publisher = {ACM Press},
  location = {Los Angeles, CA, USA},
  isbn = {0201309874},
}

@PROCEEDINGS{WALCOM2011,
  title = {International Workshop on Algorithms and Computation, 18-20 February
	2011},
  year = {2011},
  abbrev = {WALCOM},
  booktitle = {WALCOM'11: } # PROC # {International Workshop on Algorithms and Computation},
  editor = {Naoki Katoh and Amit Kumar},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {New Delhi, India},
  isbn = {9783642190933},
  doi = {10.1007/978-3-642-19094-0}
}

@PROCEEDINGS{CHI1995,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 07-11 May
	1995},
  year = {1995},
  abbrev = {CHI},
  booktitle = {CHI'95: } # PROC # {SIGCHI conference on Human Factors in Computing
	Systems},
  editor = {Katz, Irvin R. and Mack, Robert and Marks, Linn and Rosson, Mary
	Beth and Nielsen, Jakob},
  publisher = {ACM Press/Addison-Wesley Publishing Co.},
  location = {Denver, CO, USA},
  isbn = {0201847051},
}

@PROCEEDINGS{VIS1992,
  title = {IEEE Conference on Visualization, 19-23 October 1992},
  year = {1992},
  abbrev = {VIS},
  booktitle = {Visualization'92: } # PROC # {IEEE Conference on Visualization},
  editor = {Arie Kaufman and Gregory M. Nielson},
  publisher = {IEEE Computer Society},
  location = {Boston, MA, USA},
  isbn = {0818628979},
}

@PROCEEDINGS{GD2006,
  title = {International Symposium on Graph Drawing, 18-20 September 2006},
  year = {2006},
  abbrev = {GD},
  booktitle = {GD'06: } # PROC # {International Symposium on Graph Drawing},
  editor = {Michael Kaufmann and Dorothea Wagner},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Karlsruhe, Germany},
  isbn = {9783540709039},
  doi = {10.1007/978-3-540-70904-6}
}

@PROCEEDINGS{INFOVIS1999,
  title = {IEEE Symposium on Information Visualization, 24-29 October 1999},
  year = {1999},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'99: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Daniel Keim and Graham Wills},
  publisher = {IEEE Computer Society},
  location = {San Francisco, CA, USA},
  isbn = {0769504310},
}

@PROCEEDINGS{INFOVIS1999,
  title = {IEEE Symposium on Information Visualization, 24-29 October 1999},
  year = {1999},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'99: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Daniel Keim and Graham Wills},
  publisher = {IEEE Computer Society},
  location = {San Francisco, CA, USA},
  isbn = {0769504310},
}

@PROCEEDINGS{ProVis2004,
  title = {Program Visualization Workshop, 1-2 July 2004},
  year = {2004},
  abbrev = {ProVis},
  booktitle = PROC # {Program Visualization Workshop 2000},
  editor = {Ari Korhonen},
  publisher = {University of Warwick Research Report CS-RR-407},
  location = {Coventry, UK},
  isbn = {0902683748},
  url = {http://www.dcs.warwick.ac.uk/pvw04/}
}

@PROCEEDINGS{GD1999,
  title = {International Symposium on Graph Drawing, 15-19 September 1999},
  year = {1999},
  abbrev = {GD},
  booktitle = {GD'99: } # PROC # {International Symposium on Graph Drawing},
  editor = {Jan Kratochv\'{\i}yl},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Stirin Castle, Czech Republic},
  isbn = {3540669043},
  doi = {10.1007/3-540-46648-7}
}

@PROCEEDINGS{GD1999,
  title = {International Symposium on Graph Drawing, 15-19 September 1999},
  year = {1999},
  abbrev = {GD},
  booktitle = {GD'99: } # PROC # {International Symposium on Graph Drawing},
  editor = {Jan Kratochv\'{\i}yl},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Stirin Castle, Czech Republic},
  isbn = {3540669043},
  doi = {10.1007/3-540-46648-7}
}

@PROCEEDINGS{VIEW2006,
  title = {Visual Information Expert Workshop, 24-25 April 2006},
  year = {2006},
  abbrev = {VIEW},
  booktitle = {VIEW'06: } # PROC # {Visual Information Expert Workshop},
  editor = {Pierre P. L\'evy and B\'en\'edicte Le Grand and Fran\c{c}ois Poulet
	and Michel Soto and Laszlo Darago and Laurent Toubiana and Jean-Fran\c{c}ois
	Vibert},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Paris, France},
  isbn = {3540710264},
  doi = {10.1007/978-3-540-71027-1}
}

@PROCEEDINGS{VISSOFT2009,
  title = {IEEE International Workshop onVisualizing Software for Understanding
	and Analysis, 25-26 September 2009},
  year = {2009},
  abbrev = {VISSOFT},
  booktitle = {VisSoft'09: } # PROC # {IEEE International Workshop on Visualizing
	Software for Understanding and Analysis},
  editor = {Michele Lanza and Hausi A. M\"uller and Margaret-Anne Storey},
  publisher = {IEEE Computer Society},
  location = {Edmonton, Canada},
  isbn = {9781424450251},
}

@PROCEEDINGS{VISSYM2000,
  title = {Joint Eurographics - IEEE TCVG Symposium on Visualization, 29-30
	May 2000},
  year = {2000},
  abbrev = {VISSYM},
  booktitle = {VisSym'00: } # PROC # {Joint Eurographics - IEEE TCVG Symposium on
	Visualization},
  editor = {Wim de Leeuw and Robert van Liere},
  publisher = {Eurographics Association},
  location = {Amsterdam, Netherlands},
  isbn = {3211835156},
  url = {http://diglib.eg.org/EG/DL/WS/VisSym/VisSym00}
}

@PROCEEDINGS{APWEB2009,
  title = {Joint International Conferences APWeb/WAIM, 2-4 April 2009},
  year = {2009},
  abbrev = {APWEB},
  booktitle = {Advances in Data and Web Management: } # PROC # {Joint International
	Conferences APWeb/WAIM 2009},
  editor = {Qing Li and Ling Feng and Jian Pei and Sean X.Wang and Xiaofang Zhou
	and Qiao-Ming Zhu},
  publisher = {Springer},
  location = {Suzhou, China},
  isbn = {9783642006715},
  doi = {10.1007/978-3-642-00672-2}
}

@PROCEEDINGS{CDVE2007,
  title = {International Conference on Cooperative Design, Visualization, and
	Engineering, 16-20 September 2007},
  year = {2007},
  abbrev = {CDVE},
  booktitle = {CDVE'07: } # PROC # {International Conference on Cooperative Design,
	Visualization, and Engineering},
  editor = {Yuhua Luo},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Shanghai, China},
  isbn = {9783540747796},
  doi = {10.1007/978-3-540-74780-2}
}

@PROCEEDINGS{VISSOFT2007,
  title = {IEEE International Workshop onVisualizing Software for Understanding
	and Analysis, 25-26 June 2007},
  year = {2007},
  abbrev = {VISSOFT},
  booktitle = {VisSoft'07: } # PROC # {IEEE International Workshop on Visualizing
	Software for Understanding and Analysis},
  editor = {Jonathan I. Maletic and Alexandru Telea and Andrian Marcus},
  publisher = {IEEE Computer Society},
  location = {Banff, Canada},
  isbn = {1424406005},
}

@PROCEEDINGS{VISSOFT2007,
  title = {IEEE International Workshop onVisualizing Software for Understanding
	and Analysis, 25-26 June 2007},
  year = {2007},
  abbrev = {VISSOFT},
  booktitle = {VisSoft'07: } # PROC # {IEEE International Workshop on Visualizing
	Software for Understanding and Analysis},
  editor = {Jonathan I. Maletic and Alexandru Telea and Andrian Marcus},
  publisher = {IEEE Computer Society},
  location = {Banff, Canada},
  isbn = {1424406005},
}

@PROCEEDINGS{VISSOFT2005,
  title = {IEEE International Workshop on Visualizing Software for Understanding
	and Analysis, 25 September 2005},
  year = {2005},
  abbrev = {VISSOFT},
  booktitle = {VisSoft'05: } # PROC # {IEEE International Workshop on Visualizing
	Software for Understanding and Analysis},
  editor = {Andrian Marcus and Jonathan I. Maletic and Margaret-Anne Storey and
	Michele Lanza and St\'ephane Ducasse},
  publisher = {IEEE Computer Society},
  location = {Budapest, Hungary},
  isbn = {0780395409},
}

@PROCEEDINGS{UIST2001,
  title = {Annual ACM Symposium on User Interface Software and Technology, 11-14
	November 2001},
  year = {2001},
  abbrev = {UIST},
  booktitle = {UIST'01: } # PROC # {Annual ACM Symposium on User Interface Software
	and Technology},
  editor = {Marks, Joe and Mynatt, Elizabeth D.},
  publisher = {ACM Press},
  location = {Orlando, FL, USA},
  isbn = {158113438X},
}

@PROCEEDINGS{APCHI2004,
  title = {Asia Pacific Conference on Computer Human Interaction, 29 June -
	2 July 2004},
  year = {2004},
  abbrev = {APCHI},
  booktitle = {APCHI'04: } # PROC # {Asia Pacific Conference on Computer Human Interaction},
  editor = {Masood Masoodian and Steve Jones and Bill Rogers},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Rotorua, New Zealand},
  isbn = {9783540223122},
  doi = {10.1007/b98382}
}

@PROCEEDINGS{HCI2000,
  title = {Human Computer Interaction, 05-08 September 2000},
  year = {2000},
  abbrev = {HCI},
  booktitle = {People and Computers XIV -- Usability or Else! } # PROC # {Human
	Computer Interaction 2000},
  editor = {Sharon McDonald and Yvonne Waern and Gilbert Cockton},
  publisher = {Springer},
  location = {Sunderland, UK},
  isbn = {9781852333188}
}

@PROCEEDINGS{CogSci2007,
  title = {Conference of the Cognitive Science Society, 1-4 August 2007},
  year = {2007},
  abbrev = {CogSci},
  booktitle = {CogSci'07: } # PROC # {Conference of the Cognitive Science Society},
  editor = {Danielle S. McNamara and Greg Trafton},
  publisher = {Psychology Press},
  location = {Nashville, TN, USA},
  isbn = {9781605605074},
}

@PROCEEDINGS{APVIS2006,
  title = {Asia Pacific Symposium on Information Visualization, 1-3 February
	2006},
  year = {2006},
  abbrev = {APVIS},
  booktitle = {APVIS'06: } # PROC # {Asia Pacific Symposium on Information Visualization},
  editor = {Kazuo Misue and Kozo Sugiyama and Jiro Tanaka},
  publisher = {Australian Computer Society},
  series = {Conference in Research and Practice in Information Technology},
  location = {Tokyo, Japan},
  isbn = {1920682414},
}

@PROCEEDINGS{INFOVIS2003,
  title = {IEEE Symposium on Information Visualization, 20-21 October 2003},
  year = {2003},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'03: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Tamara Munzner and Stephen North},
  publisher = {IEEE Computer Society},
  location = {Seattle, WA, USA},
  isbn = {0780381548},
}

@PROCEEDINGS{INFOVIS2003,
  title = {IEEE Symposium on Information Visualization, 20-21 October 2003},
  year = {2003},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'03: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Tamara Munzner and Stephen North},
  publisher = {IEEE Computer Society},
  location = {Seattle, WA, USA},
  isbn = {0780381548},
}

@PROCEEDINGS{INFOVIS2003,
  title = {IEEE Symposium on Information Visualization, 20-21 October 2003},
  year = {2003},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'03: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Tamara Munzner and Stephen North},
  publisher = {IEEE Computer Society},
  location = {Seattle, WA, USA},
  isbn = {0780381548},
}

@PROCEEDINGS{VIS1991,
  title = {IEEE Conference on Visualization, 22-25 October 1991},
  year = {1991},
  abbrev = {VIS},
  booktitle = {Visualization'91: } # PROC # {IEEE Conference on Visualization},
  editor = {Gregory M. Nielson and Larry Rosenblum},
  publisher = {IEEE Computer Society},
  location = {San Diego, CA, USA},
  isbn = {0818622458},
}

@PROCEEDINGS{APVIS2003,
  title = {Asia Pacific Symposium on Information Visualization, 3-4 February
	2003},
  year = {2003},
  abbrev = {APVIS},
  booktitle = {APVIS'03: } # PROC # {Asia Pacific Symposium on Information Visualization},
  editor = {Tim Pattison and Bruce Thomas},
  publisher = {Australian Computer Society},
  series = {Conference in Research and Practice in Information Technology},
  location = {Adelaide, Australia},
  isbn = {1920682031},
}

@PROCEEDINGS{IWPSE2007,
  title = {International workshop on Principles of Software Evolution, 3-4 September
	2007},
  year = {2007},
  abbrev = {IWPSE},
  booktitle = {IWPSE'07: } # PROC # {International workshop on Principles of Software
	Evolution},
  editor = {Massimiliano Di Penta and Michele Lanza},
  publisher = {ACM Press},
  location = {Dubrovnik, Croatia},
  isbn = {9781595937223},
}

@PROCEEDINGS{VIP2004,
  title = {Pan-Sydney Area Workshop on Visual Information Processing, 2004},
  year = {2004},
  abbrev = {VIP},
  booktitle = {VIP'04: } # PROC # {Pan-Sydney Area Workshop on Visual Information
	Processing},
  editor = {Massimo Piccardi and Tom Hintz and Sean He and Mao Lin Huang and
	David Dagan Feng},
  publisher = {Australian Computer Society/CRPIT},
  location = {Sydney, Australia},
  isbn = {192068218X}
}

@PROCEEDINGS{VISUAL2007,
  title = {International Conference on Visual Information Systems, 28-29 June
	2007},
  year = {2007},
  abbrev = {VISUAL},
  booktitle = {VISUAL'07: Advances in Visual Information Systems},
  editor = {Guoping Qiu and Clement Leung and Xiangyang Xue and Robert Laurini},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Shanghai, China},
  isbn = {9783540764137},
  doi = {10.1007/978-3-540-76414-4}
}

@PROCEEDINGS{SODA2011,
  title = {ACM-SIAM Symposium on Discrete Algorithms, 23-25 January 2011},
  year = {2011},
  abbrev = {SODA},
  booktitle = {SODA'11: } # PROC # {ACM-SIAM Symposium on Discrete Algorithms},
  editor = {Dana Randall},
  publisher = {Society for Industrial and Applied Mathematics},
  location = {San Francisco, CA, USA}
}

@PROCEEDINGS{IHCI2007,
  title = {International Conference on Interfaces and Human Computer Interaction,
	6-8 July 2007},
  year = {2007},
  abbrev = {IHCI},
  booktitle = {IHCI'07: } # PROC # {IADIS International Conference on Interfaces
	and Human Computer Interaction},
  editor = {Antonio Palma dos Reis and Katherine Blashki and Yingcai Xiao},
  publisher = {IADIS Press},
  location = {Lisbon, Portugal},
  isbn = {9789728924393},
}

@PROCEEDINGS{VAST2007,
  title = {IEEE Symposium on Visual Analytics Science and Technology, 30 October-01
	November 2007},
  year = {2007},
  abbrev = {VAST},
  booktitle = {VAST'07: } # PROC # {IEEE Symposium on Visual Analytics Science and
	Technology},
  editor = {William Ribarsky and John Dill},
  publisher = {IEEE Computer Society},
  location = {Sacramento, CA, USA},
  isbn = {9781424416592},
}

@PROCEEDINGS{CMV2003,
  title = {International Conference on Coordinated and Multiple Views in Exploratory
	Visualization, 15 July 2003},
  year = {2003},
  abbrev = {CMV},
  booktitle = {CMV'03: } # PROC # {International Conference on Coordinated and Multiple
	Views in Exploratory Visualization},
  editor = {Jonathan Roberts},
  publisher = {IEEE Computer Society},
  location = {London, England},
  isbn = {0769520014},
}

@PROCEEDINGS{CHI1991,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 27 April-02
	May 1991},
  year = {1991},
  abbrev = {CHI},
  booktitle = {CHI'91: } # PROC # {SIGCHI conference on Human Factors in Computing
	Systems},
  editor = {Scott P. Robertson and Gary M. Olson and Judith S. Olson},
  publisher = {ACM Press},
  location = {New Orleans, LA, United States},
  isbn = {0897913833},
}

@PROCEEDINGS{EUROVIS2006,
  title = {Joint Eurographics - IEEE VGTC Symposium on Visualization, 8-10 May
	2006},
  year = {2006},
  abbrev = {EUROVIS},
  booktitle = {EuroVis'06: } # PROC # {Joint Eurographics - IEEE VGTC Symposium
	on Visualization},
  editor = {Beatriz Sousa Santos and Thomas Ertl and Kenneth I. Joy},
  publisher = {Eurographics Association},
  location = {Lisbon, Portugal},
  isbn = {3905673312},
}

@PROCEEDINGS{SCCG2006,
  title = {Spring Conference on Computer Graphics, 20-22 April 2006},
  year = {2006},
  abbrev = {SCCG},
  booktitle = {SCCG'06: } # PROC # {Spring Conference on Computer Graphics},
  editor = {Pavel Slav\'{\i}k},
  publisher = {Comenius University, Bratislava},
  location = {Casta Papiernicka, Slovak Republic},
  isbn = {8022321753},
}

@PROCEEDINGS{INFOVIS2005,
  title = {IEEE Symposium on Information Visualization, 23-25 October 2005},
  year = {2005},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'05: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {John Stasko and Matthew O. Ward},
  publisher = {IEEE Computer Society},
  location = {Minneapolis, MN, USA},
  isbn = {078039464X},
}

@PROCEEDINGS{INFOVIS2005,
  title = {IEEE Symposium on Information Visualization, 23-25 October 2005},
  year = {2005},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'05: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {John Stasko and Matthew O. Ward},
  publisher = {IEEE Computer Society},
  location = {Minneapolis, MN, USA},
  isbn = {078039464X},
}

@PROCEEDINGS{INFOVIS2005,
  title = {IEEE Symposium on Information Visualization, 23-25 October 2005},
  year = {2005},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'05: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {John Stasko and Matthew O. Ward},
  publisher = {IEEE Computer Society},
  location = {Minneapolis, MN, USA},
  isbn = {078039464X},
}

@PROCEEDINGS{INFOVIS2005,
  title = {IEEE Symposium on Information Visualization, 23-25 October 2005},
  year = {2005},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'05: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {John Stasko and Matthew O. Ward},
  publisher = {IEEE Computer Society},
  location = {Minneapolis, MN, USA},
  isbn = {078039464X},
}

@BOOK{Steele2010,
  title = {Beautiful Visualization},
  publisher = {O'Reilly},
  year = {2010},
  editor = {Julie Steele and Noah Iliinsky},
  isbn = {9781449379872},
  abstract = {Visualization is the graphic presentation of data -- portrayals meant
	to reveal complex information at a glance. Think of the familiar
	map of the New York City subway system, or a diagram of the human
	brain. Successful visualizations are beautiful not only for their
	aesthetic design, but also for elegant layers of detail that efficiently
	generate insight and new understanding. This book examines the methods
	of two dozen visualization experts who approach their projects from
	a variety of perspectives -- as artists, designers, commentators,
	scientists, analysts, statisticians, and more. Together they demonstrate
	how visualization can help us make sense of the world. Contributors
	include: Nick Bilton, Michael E. Driscoll, Jonathan Feinberg, Danyel
	Fisher, Jessica Hagy, Gregor Hochmuth, Todd Holloway, Noah Iliinsky,
	Eddie Jabbour, Valdean Klump, Aaron Koblin, Robert Kosara, Valdis
	Krebs, JoAnn Kuchera-Morin et al., Andrew Odewahn, Adam Perer, Anders
	Persson, Maximilian Schich, Matthias Shapiro, Julie Steele, Moritz
	Stefaner, Jer Thorp, Fernanda Viegas, Martin Wattenberg, and Michael
	Young.},
  booktitle = {Beautiful Visualization}
}

@PROCEEDINGS{CHIcomp1996,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 13-18 April
	1996},
  year = {1996},
  abbrev = {CHIcomp},
  booktitle = {CHI'96: Conference companion of the SIGCHI conference on Human Factors
	in Computing Systems},
  editor = {Michael J. Tauber},
  publisher = {ACM Press},
  location = {Vancouver, Canada},
  isbn = {0897918320},
}

@PROCEEDINGS{SOFTVIS2010,
  title = {ACM Symposium on Software Visualization, 25-26 October 2010},
  year = {2010},
  abbrev = {SOFTVIS},
  booktitle = {SoftVis'10: } # PROC # {Symposium on Software Visualization},
  editor = {Alexandru Telea and Carsten G\"org and Steven P. Reiss},
  publisher = {ACM Press},
  location = {Salt Lake City, UT, USA},
  isbn = {9781450300285},
}

@PROCEEDINGS{SOFTVIS2010,
  title = {ACM Symposium on Software Visualization, 25-26 October 2010},
  year = {2010},
  abbrev = {SOFTVIS},
  booktitle = {SoftVis'10: } # PROC # {Symposium on Software Visualization},
  editor = {Alexandru Telea and Carsten G\"org and Steven P. Reiss},
  publisher = {ACM Press},
  location = {Salt Lake City, UT, USA},
  isbn = {9781450300285},
}

@PROCEEDINGS{GD2008,
  title = {International Symposium on Graph Drawing, 21-24 September 2008},
  year = {2008},
  abbrev = {GD},
  booktitle = {GD'08: } # PROC # {International Symposium on Graph Drawing},
  editor = {Ioannis G. Tollis and Maurizio Patrignani},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Heraklion, Crete, Greece},
  isbn = {9783642002182},
  doi = {10.1007/978-3-642-00219-9}
}

@PROCEEDINGS{INFOVIS2004,
  title = {IEEE Symposium on Information Visualization, 10-12 October 2004},
  year = {2004},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'04: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Matthew O. Ward and Tamara Munzner},
  publisher = {IEEE Computer Society},
  location = {Austin, TX, USA},
  isbn = {0780387791},
}

@PROCEEDINGS{JSAI2006,
  title = {Japanese Society for Artificial Intelligence Conference and Workshops,
	5-9 June 2006},
  year = {2006},
  abbrev = {JSAI},
  booktitle = {New Frontiers in Artificial Intelligence: } # PROC # {Japanese Society
	for Artificial Intelligence Conference and Workshops},
  editor = {Takashi Washio and Ken Satoh and Hideaki Takeda and Akihiro Inokuchi},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Tokyo, Japan},
  isbn = {9783540699019},
  doi = {10.1007/978-3-540-69902-6}
}

@PROCEEDINGS{GD1998,
  title = {International Symposium on Graph Drawing, 13-15 August 1998},
  year = {1998},
  abbrev = {GD},
  booktitle = {GD'98: } # PROC # {International Symposium on Graph Drawing},
  editor = {Sue H. Whitesides},
  publisher = {Springer},
  series = {Lecture Notes in Computer Science},
  location = {Montreal, Canada},
  isbn = {9783540654735},
  doi = {10.1007/3-540-37623-2}
}

@PROCEEDINGS{INFOVIS1998,
  title = {IEEE Symposium on Information Visualization, 19-20 October 1998},
  year = {1998},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'98: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Graham Wills and John Dill},
  publisher = {IEEE Computer Society},
  location = {Research Triangle Park, NC, USA},
  isbn = {0818690933},
}

@PROCEEDINGS{INFOVIS1998,
  title = {IEEE Symposium on Information Visualization, 19-20 October 1998},
  year = {1998},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'98: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Graham Wills and John Dill},
  publisher = {IEEE Computer Society},
  location = {Research Triangle Park, NC, USA},
  isbn = {0818690933},
}

@PROCEEDINGS{INFOVIS1998,
  title = {IEEE Symposium on Information Visualization, 19-20 October 1998},
  year = {1998},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'98: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Graham Wills and John Dill},
  publisher = {IEEE Computer Society},
  location = {Research Triangle Park, NC, USA},
  isbn = {0818690933},
}

@PROCEEDINGS{ICCVG2004,
  title = {International Conference on Computer Vision and Graphics, 22-24 September
	2004},
  year = {2004},
  abbrev = {ICCVG},
  booktitle = {ICCVG'04: } # PROC # {International Conference on Computer Vision
	and Graphics},
  editor = {Konrad Wojciechowski and Bogdan Smolka and Henryk Palus and Ryszard
	Kozera and Wladyslaw Skarbek and Lyle Noakes},
  publisher = {Springer},
  location = {Warsaw, Poland},
  isbn = {9781402041785},
  doi = {10.1007/1-4020-4179-9}
}

@PROCEEDINGS{INFOVIS2002,
  title = {IEEE Symposium on Information Visualization, 27 October - 1 November
	2002},
  year = {2002},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'02: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Pak Chung Wong and Keith Andrews},
  publisher = {IEEE Computer Society},
  location = {Boston, MA, USA},
  isbn = {076951751X},
}

@PROCEEDINGS{INFOVIS2002,
  title = {IEEE Symposium on Information Visualization, 27 October - 1 November
	2002},
  year = {2002},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'02: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Pak Chung Wong and Keith Andrews},
  publisher = {IEEE Computer Society},
  location = {Boston, MA, USA},
  isbn = {076951751X},
}

@PROCEEDINGS{INFOVIS2002,
  title = {IEEE Symposium on Information Visualization, 27 October - 1 November
	2002},
  year = {2002},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'02: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Pak Chung Wong and Keith Andrews},
  publisher = {IEEE Computer Society},
  location = {Boston, MA, USA},
  isbn = {076951751X},
}

@PROCEEDINGS{INFOVIS2002,
  title = {IEEE Symposium on Information Visualization, 27 October - 1 November
	2002},
  year = {2002},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'02: } # PROC # {IEEE Symposium on Information Visualization},
  editor = {Pak Chung Wong and Keith Andrews},
  publisher = {IEEE Computer Society},
  location = {Boston, MA, USA},
  isbn = {076951751X},
}

@PROCEEDINGS{VAST2006,
  title = {IEEE Symposium on Visual Analytics Science and Technology, 31 October-02
	November 2006},
  year = {2006},
  abbrev = {VAST},
  booktitle = {VAST'06: } # PROC # {IEEE Symposium on Visual Analytics Science and
	Technology},
  editor = {Pak Chung Wong and Daniel Keim},
  publisher = {IEEE Computer Society},
  location = {Baltimore, MD, USA},
  isbn = {1424405912},
}

@PROCEEDINGS{VIS1997,
  title = {IEEE Conference on Visualization, 18-24 October 1997},
  year = {1997},
  abbrev = {VIS},
  booktitle = {Visualization'97: } # PROC # {IEEE Conference on Visualization},
  editor = {Roni Yagel and Hans Hagen},
  publisher = {ACM Press},
  location = {Phoenix, AZ, USA},
  isbn = {1581130112},
}

@PROCEEDINGS{VIS1996,
  title = {IEEE Conference on Visualization, 27 October - 1 November 1996},
  year = {1996},
  abbrev = {VIS},
  booktitle = {Visualization'96: } # PROC # {IEEE Conference on Visualization},
  editor = {Roni Yagel and Gregory M. Nielson},
  publisher = {ACM Press},
  location = {San Francisco, CA, USA},
  isbn = {0897918649},
}

@PROCEEDINGS{BioVis2011,
  title = {IEEE Symposium on Biological Data Visualization, 23-24 October 2011},
  year = {2011},
  abbrev = {BioVis},
  booktitle = {BioVis'11: } # PROC # {IEEE Symposium on Biological Data Visualization},
  publisher = {IEEE Computer Society},
  location = {Providence, RI, USA}
}

@PROCEEDINGS{EuroCG2011,
  title = {European Workshop on Computational Geometry, 28-30 March 2011},
  year = {2011},
  abbrev = {EuroCG},
  booktitle = {EuroCG'11: Book of Abstracts of the European Workshop on Computational
	Geometry},
  location = {Morschach, Switzerland}
}

@PROCEEDINGS{EuroCG2011,
  title = {European Workshop on Computational Geometry, 28-30 March 2011},
  year = {2011},
  abbrev = {EuroCG},
  booktitle = {EuroCG'11: Book of Abstracts of the European Workshop on Computational
	Geometry},
  location = {Morschach, Switzerland}
}

@PROCEEDINGS{ISIE2011,
  title = {International Conference on Intelligence Science and Information
	Engineering, 20-21 December 2011},
  year = {2011},
  abbrev = {ISIE},
  booktitle = {ISIE'11: } # PROC # {International Conference on Intelligence Science
	and Information Engineering},
  publisher = {IEEE Computer Society},
  location = {Wuhan, China},
  isbn = {9780769544809}
}

@PROCEEDINGS{SIGGRAPHposter2011,
  title = {Special Interest Group on Computer Graphics and Interactive Techniques
	Conference, 07-11 August 2011},
  year = {2011},
  abbrev = {SIGGRAPHposter},
  booktitle = {SIGGRAPH'11: Posters of the Special Interest Group on Computer Graphics
	and Interactive Techniques Conference},
  location = {Vancouver, Canada}
}

@PROCEEDINGS{INFOVISposter2010,
  title = {IEEE Information Visualization Conference, 24-29 October 2010},
  year = {2010},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'10: Poster at the IEEE Conference on Information Visualization},
  location = {Salt Lake City, UT, USA},
}

@PROCEEDINGS{ESEM2009,
  title = {International Symposium on Empirical Software Engineering and Measurement,
	15-16 October 2009},
  year = {2009},
  abbrev = {ESEM},
  booktitle = {ESEM'09: } # PROC # {International Symposium on Empirical Software
	Engineering and Measurement},
  publisher = {IEEE Computer Society},
  location = {Lake Buena Vista, FL, USA},
  isbn = {9781424448418},
}

@PROCEEDINGS{GeoInformatics2009,
  title = {International Conference on GeoInformatics, 12-14 August 2009},
  year = {2009},
  abbrev = {GeoInformatics},
  booktitle = PROC # {International Conference on GeoInformatics'09},
  publisher = {IEEE Computer Society},
  location = {Fairfax, VA, USA},
  isbn = {9781424445622}
}

@PROCEEDINGS{FAMOOSr2008,
  title = {Workshop on FAMIX and Moose in Reengineering, 17 October 2008},
  year = {2008},
  abbrev = {FAMOOSr},
  booktitle = {FAMOOSr'08: } # PROC # {Workshop on FAMIX and Moose in Reengineering},
  location = {Antwerp, Belgium}
}

@PROCEEDINGS{FHTW2008,
  title = {Workshop on Technology for Family History and Genealogical Research},
  year = {2008},
  abbrev = {FHTW},
  booktitle = {FHTW'08: } # PROC # {Workshop on Technology for Family History and
	Genealogical Research},
}

@PROCEEDINGS{INFOVISposter2008,
  title = {IEEE Information Visualization Conference, 19-24 October 2008},
  year = {2008},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'08: Poster at the IEEE Conference on Information Visualization},
  location = {Columbus, OH, USA},
}

@PROCEEDINGS{INFOVISposter2008,
  title = {IEEE Information Visualization Conference, 19-24 October 2008},
  year = {2008},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'08: Poster at the IEEE Conference on Information Visualization},
  location = {Columbus, OH, USA},
}

@PROCEEDINGS{SCG2008,
  title = {Symposium on Computational Geometry, 9-11 June 2008},
  year = {2008},
  abbrev = {SCG},
  booktitle = {SCG'08: } # PROC # {Symposium on Computational Geometry},
  publisher = {ACM Press},
  location = {College Park, MD, USA},
  isbn = {9781605580715},
}

@PROCEEDINGS{SOFTVIS2008,
  title = {ACM Symposium on Software Visualization, 16-17 September 2008},
  year = {2008},
  abbrev = {SOFTVIS},
  booktitle = {SoftVis'08: } # PROC # {Symposium on Software Visualization},
  publisher = {ACM Press},
  location = {Herrsching am Ammersee, Germany},
  isbn = {9781605581125}
}

@PROCEEDINGS{INFOVISposter2007,
  title = {IEEE Information Visualization Conference, 28-30 October 2007},
  year = {2007},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'07: Poster Compendium of the IEEE Conference on Information
	Visualization},
  location = {Sacramento, CA, USA},
  url = {http://conferences.computer.org/infovis/files/compendium2007.pdf}
}

@PROCEEDINGS{ISCE2007,
  title = {IEEE International Symposium on Consumer Electronics, 20-23 June
	2007},
  year = {2007},
  abbrev = {ISCE},
  booktitle = {ISCE'07: } # PROC # {IEEE International Symposium on Consumer Electronics},
  publisher = {IEEE Computer Society},
  location = {Dallas, TX, USA},
  isbn = {9781424411092},
}

@PROCEEDINGS{IV2007,
  title = {International Conference on Information Visualisation, 2-6 July 2007},
  year = {2007},
  abbrev = {IV},
  booktitle = {IV'07: } # PROC # {International Conference on Information Visualisation},
  publisher = {IEEE Computer Society},
  location = {Z\"urich, Switzerland},
  isbn = {0769529003},
}

@PROCEEDINGS{IV2007,
  title = {International Conference on Information Visualisation, 2-6 July 2007},
  year = {2007},
  abbrev = {IV},
  booktitle = {IV'07: } # PROC # {International Conference on Information Visualisation},
  publisher = {IEEE Computer Society},
  location = {Z\"urich, Switzerland},
  isbn = {0769529003},
}

@PROCEEDINGS{IV2007,
  title = {International Conference on Information Visualisation, 2-6 July 2007},
  year = {2007},
  abbrev = {IV},
  booktitle = {IV'07: } # PROC # {International Conference on Information Visualisation},
  publisher = {IEEE Computer Society},
  location = {Z\"urich, Switzerland},
  isbn = {0769529003},
}

@PROCEEDINGS{IV2007,
  title = {International Conference on Information Visualisation, 2-6 July 2007},
  year = {2007},
  abbrev = {IV},
  booktitle = {IV'07: } # PROC # {International Conference on Information Visualisation},
  publisher = {IEEE Computer Society},
  location = {Z\"urich, Switzerland},
  isbn = {0769529003},
}

@PROCEEDINGS{CHIabs2006,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 22-27 April
	2006},
  year = {2006},
  abbrev = {CHI},
  booktitle = {CHI'06: Extended abstracts of the SIGCHI conference on Human Factors
	in Computing Systems},
  publisher = {ACM Press},
  location = {Montreal, Quebec, Canada},
  isbn = {1595932984},
}

@PROCEEDINGS{CIKM2006,
  title = {ACM International Conference on Information and Knowledge Management,
	5-11 November 2006},
  year = {2006},
  abbrev = {CIKM},
  booktitle = {CIKM'06: } # PROC # {ACM International Conference on Information
	and Knowledge Management},
  publisher = {ACM Press},
  location = {Arlington, VA, USA},
  isbn = {1595934332},
}

@PROCEEDINGS{UISTdemos2006,
  title = {Annual ACM Symposium on User Interface Software and Technology, 15-18
	October 2006},
  year = {2006},
  abbrev = {UISTdemos},
  booktitle = {UIST'06: Adjunct } # PROC # {Annual ACM Symposium on User Interface
	Software and Technology},
  publisher = {ACM Press},
  location = {Montreux, Switzerland},
  isbn = {1595933131}
}

@PROCEEDINGS{UISTdemos2006,
  title = {Annual ACM Symposium on User Interface Software and Technology, 15-18
	October 2006},
  year = {2006},
  abbrev = {UISTdemos},
  booktitle = {UIST'06: Adjunct } # PROC # {Annual ACM Symposium on User Interface
	Software and Technology},
  publisher = {ACM Press},
  location = {Montreux, Switzerland},
  isbn = {1595933131}
}

@PROCEEDINGS{AFRIGRAPH2004,
  title = {International Conference on Computer Graphics, Virtual Reality, Visualisation
	and Interaction in Africa, 03-05 November 2004},
  year = {2004},
  abbrev = {AFRIGRAPH},
  booktitle = {AFRIGRAPH'04: } # PROC # {International Conference on Computer Graphics,
	Virtual Reality, Visualisation and Interaction in Africa},
  publisher = {ACM Press},
  location = {Cape Town, South Africa},
  isbn = {1581138636},
}

@PROCEEDINGS{CIFT2004,
  title = {Colloque International sur la Fouille de Texte, 21-25 June 2004},
  year = {2004},
  abbrev = {CIFT},
  booktitle = {CIFT'03: } # PROC # {Colloque International sur la Fouille de Texte},
  location = {La Rochelle, France}
}

@PROCEEDINGS{CODATA2004,
  title = {CODATA Prague Workshop on Information Visualisation, Presentation
	and Design, 29-31 March 2004},
  year = {2004},
  abbrev = {CODATA},
  booktitle = {CODATA'04: } # PROC # {Workshop on Information Visualisation, Presentation
	and Design},
  location = {Prague, Czech Republic},
}

@PROCEEDINGS{INFOVISposter2004,
  title = {IEEE Symposium on Information Visualization, 10-12 October 2004},
  year = {2004},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'04: Poster Compendium of the IEEE Symposium on Information
	Visualization},
  location = {Austin, TX, USA},
  url = {http://conferences.computer.org/infovis/files/compendium2004.pdf}
}

@PROCEEDINGS{VISposter2004,
  title = {IEEE Conference on Visualization, 10-15 October 2004},
  year = {2004},
  abbrev = {VISposter},
  booktitle = {Visualization'04: Poster Compendium of the IEEE Conference on Visualization},
  location = {Austin, TX, USA},
}

@PROCEEDINGS{WPC2004,
  title = {IEEE Symposium on Information Visualization, 24-26 June 2004},
  year = {2004},
  abbrev = {WPC},
  booktitle = {WPC'04: } # PROC # {IEEE Workshop on Program Comprehension},
  publisher = {IEEE Computer Society},
  location = {Bari, Italy},
  isbn = {0769521495},
}

@PROCEEDINGS{CGI2003,
  title = {Computer Graphics International, 09-11 July 2003},
  year = {2003},
  abbrev = {CGI},
  booktitle = PROC # {Computer Graphics International 2003},
  publisher = {IEEE Computer Society},
  location = {Tokyo, Japan},
  isbn = {0769519466},
}

@PROCEEDINGS{FGWM2003,
  title = {Workshop on Knowledge and Experience Management, 6-8 October 2003},
  year = {2003},
  abbrev = {FGWM},
  booktitle = {FGWM'03: } # PROC # {Workshop on Knowledge and Experience Management},
  location = {Karlsruhe, Germany}
}

@PROCEEDINGS{INFOVISposter2003,
  title = {IEEE Symposium on Information Visualization, 20-21 October 2003},
  year = {2003},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'03: Poster Compendium of the IEEE Symposium on Information
	Visualization},
  location = {Seattle, WA, USA},
  url = {http://conferences.computer.org/infovis/files/compendium2003.pdf}
}

@PROCEEDINGS{INFOVISposter2003,
  title = {IEEE Symposium on Information Visualization, 20-21 October 2003},
  year = {2003},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'03: Poster Compendium of the IEEE Symposium on Information
	Visualization},
  location = {Seattle, WA, USA},
  url = {http://conferences.computer.org/infovis/files/compendium2003.pdf}
}

@PROCEEDINGS{INFOVISposter2003,
  title = {IEEE Symposium on Information Visualization, 20-21 October 2003},
  year = {2003},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'03: Poster Compendium of the IEEE Symposium on Information
	Visualization},
  location = {Seattle, WA, USA},
  url = {http://conferences.computer.org/infovis/files/compendium2003.pdf}
}

@PROCEEDINGS{INFOVISposter2003,
  title = {IEEE Symposium on Information Visualization, 20-21 October 2003},
  year = {2003},
  abbrev = {INFOVISposter},
  booktitle = {InfoVis'03: Poster Compendium of the IEEE Symposium on Information
	Visualization},
  location = {Seattle, WA, USA},
  url = {http://conferences.computer.org/infovis/files/compendium2003.pdf}
}

@PROCEEDINGS{IV2003,
  title = {International Conference on Information Visualisation, 16-18 July
	2003},
  year = {2003},
  abbrev = {IV},
  booktitle = {IV'03: } # PROC # {International Conference on Information Visualisation},
  publisher = {IEEE Computer Society},
  location = {London, UK},
  isbn = {0769519881},
}

@PROCEEDINGS{AVI2002,
  title = {Working Conference on Advanced Visual Interfaces, 22-24 May 2002},
  year = {2002},
  abbrev = {AVI},
  booktitle = {AVI'02: } # PROC # {Working Conference on Advanced Visual Interfaces},
  publisher = {ACM Press},
  location = {Trento, Italy},
  isbn = {1581135378},
}

@PROCEEDINGS{AVI2002,
  title = {Working Conference on Advanced Visual Interfaces, 22-24 May 2002},
  year = {2002},
  abbrev = {AVI},
  booktitle = {AVI'02: } # PROC # {Working Conference on Advanced Visual Interfaces},
  publisher = {ACM Press},
  location = {Trento, Italy},
  isbn = {1581135378},
}

@PROCEEDINGS{IV2002,
  title = {International Conference on Information Visualisation, 10-12 July
	2002},
  year = {2002},
  abbrev = {IV},
  booktitle = {IV'02: } # PROC # {International Conference on Information Visualisation},
  publisher = {IEEE Computer Society},
  location = {London, UK},
  isbn = {0769516564},
}

@PROCEEDINGS{CHIabs2000,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 01-06 April
	2000},
  year = {2000},
  abbrev = {CHI},
  booktitle = {CHI'00: Extended abstracts of the SIGCHI conference on Human Factors
	in Computing Systems},
  publisher = {ACM Press},
  location = {The Hague, Netherlands},
  isbn = {1581132484},
}

@PROCEEDINGS{ICTAI2000,
  title = {Internationals Conference on Tools with Artificial Intelligence,
	13-15 November 2000},
  year = {2000},
  abbrev = {ICTAI},
  booktitle = {ICTAI'00: } # PROC # {Internationals Conference on Tools with Artificial
	Intelligence},
  publisher = {IEEE Computer Society},
  location = {Vancouver, BC, Canada},
  isbn = {0769509096},
}

@PROCEEDINGS{INFOVIS2000,
  title = {IEEE Symposium on Information Visualization, 9-10 October 2000},
  year = {2000},
  abbrev = {INFOVIS},
  booktitle = {InfoVis'00: } # PROC # {IEEE Symposium on Information Visualization},
  publisher = {IEEE Computer Society},
  location = {Salt Lake City, UT, USA},
  isbn = {0769508049},
}

@PROCEEDINGS{LISA2000,
  title = {Large Installation System Administration Conference, 3-8 December
	2000},
  year = {2000},
  abbrev = {LISA},
  booktitle = {LISA'00: } # PROC # {Large Installation System Administration Conference},
  location = {New Orleans, LA, USA}
}

@PROCEEDINGS{CHIabs1999,
  title = {SIGCHI Conference on Human Factors in Computing Systems, 15-20 May
	1999},
  year = {1999},
  abbrev = {CHI},
  booktitle = {CHI'99: Extended abstracts of the SIGCHI conference on Human Factors
	in Computing Systems},
  publisher = {ACM Press},
  location = {Pittsburgh, PA, USA},
  isbn = {1581131585},
}

@PROCEEDINGS{SOFTVIS1999,
  title = {Software Visualisation Workshop, 3-4 December 1999},
  year = {1999},
  abbrev = {SOFTVIS},
  booktitle = {SoftVis'99: } # PROC # {Software Visualisation Workshop},
  location = {Sydney, Australia},
}

@PROCEEDINGS{VL1993,
  title = {IEEE Workshop on Visual Languages, 24-27 August 1993},
  year = {1993},
  abbrev = {VL},
  booktitle = {VL'93: } # PROC # {IEEE Workshop on Visual Languages},
  publisher = {IEEE Computer Society},
  location = {Bergen, Norway},
  isbn = {0818639709},
}

@PROCEEDINGS{WITS1993,
  title = {Workshop on Information Technology and Systems, 4-5 December 1993},
  year = {1993},
  abbrev = {WITS},
  booktitle = {WITS'93: } # PROC # {Workshop on Information Technology and Systems},
  location = {Orlando, FL, USA},
}

@PROCEEDINGS{HICSS1992,
  title = {Hawaii International Conference on System Sciences, 7-10 January
	1992},
  year = {1992},
  abbrev = {HICSS},
  booktitle = {HICSS'92: } # PROC # {Hawaii International Conference on System Sciences},
  publisher = {IEEE Computer Society},
  location = {Kauai, HI, USA},
  isbn = {081862440X},
}