DevLan/vispubs huggingface dataset:
Volume deformation for tensor visualization
Authors: Xiaoqiang Zheng, Alex T. Pang
Published at Vis, 2002

Visualizing second-order 3D tensor fields continue to be a challenging task. Although there are several algorithms that have been presented, no single algorithm by itself is sufficient for the analysis because of the complex nature of tensor fields. In this paper, we present two new methods, based on volume deformation, to show the effects of the tensor field upon its underlying media. We focus on providing a continuous representation of the nature of the tensor fields. Each of these visualization algorithms is good at displaying some particular properties of the tensor field.
Volume warping for adaptive isosurface extraction
Authors: Laurent Balmelli, Christopher J. Morris 0001, Gabriel Taubin, Fausto Bernardini
Published at Vis, 2002

Polygonal approximations of isosurfaces extracted from uniformly sampled volumes are increasing in size due to the availability of higher resolution imaging techniques. The large number of I primitives represented hinders the interactive exploration of the dataset. Though many solutions have been proposed to this problem, many require the creation of isosurfaces at multiple resolutions or the use of additional data structures, often hierarchical, to represent the volume. We propose a technique for adaptive isosurface extraction that is easy to implement and allows the user to decide the degree of adaptivity as well as the choice of isosurface extraction algorithm. Our method optimizes the extraction of the isosurface by warping the volume. In a warped volume, areas of importance (e.g. containing significant details) are inflated while unimportant ones are contracted. Once the volume is warped, any extraction algorithm can be applied. The extracted mesh is subsequently unwarped such that the warped areas are rescaled to their initial proportions. The resulting isosurface is represented by a mesh that is more densely sampled in regions decided as important.
Volumetric shadows using splatting
Authors: Caixia Zhang, Roger Crawfis
Published at Vis, 2002

This paper describes an efficient algorithm to model the light attenuation due to a participating media with low albedo. The light attenuation is modeled using splatting volume renderer for both the viewer and the light source. During the rendering, a 2D shadow buffer attenuates the light for each pixel. When the contribution of a footprint is added to the image buffer, as seen from the eye, we add the contribution to the shadow buffer, as seen from the light source. We have generated shadows for point lights and parallel lights using this algorithm. The shadow algorithm has been extended to deal with multiple light sources and projective textured lights.
XFastMesh: fast view-dependent meshing from external memory
Authors: Christopher DeCoro, Renato Pajarola
Published at Vis, 2002

We present a novel disk-based multiresolution triangle mesh data structure that supports paging and view-dependent rendering of very large meshes at interactive frame rates from external memory. Our approach, called XFastMesh, is based on a view-dependent mesh simplification framework that represents half-edge collapse operations in a binary hierarchy known as a merge-tree forest. The proposed technique partitions the merge-tree forest into so-called detail blocks, which consist of binary subtrees, that are stored on disk. We present an efficient external memory data structure and file format that stores all detail information of the multiresolution triangulation method using significantly less storage then previously reported approaches. Furthermore, we present a paging algorithm that provides efficient loading and interactive rendering of large meshes from external memory at varying and view-dependent level-of-detail. The presented approach is highly efficient both in terms of space cost and paging performance.
A hybrid layout algorithm for sub-quadratic multidimensional scaling
Authors: Alistair Morrison, Greg Ross, Matthew Chalmers
Published at InfoVis, 2002

Many clustering and layout techniques have been used for structuring and visualising complex data. This paper is inspired by a number of such contemporary techniques and presents a novel hybrid approach based upon stochastic sampling, interpolation and spring models. We use Chalmers' 1996 O(N/sup 2/) spring model as a benchmark when evaluating our technique, comparing layout quality and run times using data sets of synthetic and real data. Our algorithm runs in O(N/spl radic/N) and executes significantly faster than Chalmers' 1996 algorithm, whilst producing superior layouts. In reducing complexity and run time, we allow the visualisation of data sets of previously infeasible size. Our results indicate that our method is a solid foundation for interactive and visual exploration of data.
A space-optimized tree visualization
Authors: Quang Vinh Nguyen, Mao Lin Huang
Published at InfoVis, 2002

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.
ACE: a fast multiscale eigenvectors computation for drawing huge graphs
Authors: Yehuda Koren, Liran Carmel, David Harel
Published at InfoVis, 2002

We present an extremely fast graph drawing algorithm for very large graphs, which we term ACE (for Algebraic multigrid Computation of Eigenvectors). ACE exhibits an improvement of something like two orders of magnitude over the fastest algorithms we are aware of; it draws graphs of millions of nodes in less than a minute. ACE finds an optimal drawing by minimizing a quadratic energy function. The minimization problem is expressed as a generalized eigenvalue problem, which is rapidly solved using a novel algebraic multigrid technique. The same generalized eigenvalue problem seems to come up also in other fields, hence ACE appears to be applicable outside of graph drawing too.
Angular brushing of extended parallel coordinates
Authors: Helwig Hauser, Florian Ledermann, Helmut Doleisch
Published at InfoVis, 2002

In this paper we present angular brushing for parallel coordinates (PC) as a new approach to highlighting rational data-properties, i.e., features which - in a non-separable way - depend on two data dimensions. We also demonstrate smooth brushing as an intuitive tool for specifying nonbinary degree-of-interest functions (for focus+context visualization). We also briefly describe our implementation as well as its application to the visualization of CFD data.
Arc diagrams: visualizing structure in strings
Authors: Martin Wattenberg
Published at InfoVis, 2002

This paper introduces a new visualization method, the arc diagram, which is capable of representing complex patterns of repetition in string data. Arc diagrams improve over previous methods such as dotplots because they scale efficiently for strings that contain many instances of the same subsequence. This paper describes design and implementation issues related to arc diagrams and shows how they may be applied to visualize such diverse data as music, text, and compiled code.
Beamtrees: compact visualization of large hierarchies
Authors: Frank van Ham, Jarke J. van Wijk
Published at InfoVis, 2002

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.
Building a visual database for example-based graphics generation
Authors: Michelle X. Zhou, Min Chen, Ying Feng
Published at InfoVis, 2002

Example-based graphics generation systems automatically create new information visualizations by learning from existing graphic examples. As part of the effort on developing a general-purpose example-based generation system, we are building a visual database of graphic examples. In this paper, we address two main issues involved in constructing such a database: example selection and example modeling. As a result, our work offers three unique contributions: First, we build a visual database that contains a diverse collection of well-designed examples. Second, we develop a feature-based scheme to model all examples uniformly and accurately. Third, our visual database brings several important implications to the area of information visualization.
Case study: visualizing sets of evolutionary trees
Authors: Nina Amenta, Jeff Klingner
Published at InfoVis, 2002

We describe a visualization tool which allows a biologist to explore a large set of hypothetical evolutionary trees. Interacting with such a dataset allows the biologist to identify distinct hypotheses about how different species or organisms evolved, which would not have been clear from traditional analyses. Our system integrates a point-set visualization of the distribution of hypothetical trees with detail views of an individual tree, or of a consensus tree summarizing a subset of trees. Efficient algorithms were required for the key tasks of computing distances between trees, finding consensus trees, and laying out the point-set visualization.
Demystifying venture capital investing
Authors: Mei C. Chuah
Published at InfoVis, 2002

Since the crash of the dot.coms, investors have gotten a lot more careful with where they place their money. Now more than ever it becomes really important for venture capitalists (VCs) to monitor the state of the startups market and continually update their investment strategy to suit the rapidly changing market conditions. This paper presents three new visualization metaphors (Spiral Map, TimeTicker, and Double Histogram) for monitoring the startups market. While we are focusing on the VC domain, the visual metaphors developed are general and can be easily applied to other domains.
Display design for the eye and mind
Authors: Stephen M. Kosslyn
Published at InfoVis, 2002

Complex sets of numbers often can be effectively digested only after they are illustrated in charts, graphs or diagrams. However, some of these pictures are worth far less than the proverbial 1,000 words. If a visual display taxes the human perceptual, memory, or cognitive systems, it will be difficult to understand. This talk shows how facts about human information processing can guide one to design “articulate” graphics, which can be read easily and understood immediately. This information is organized into three general “maxims,” which in turn are used to organize sets of individual principles. Each of the principles is illustrated with “good” and “bad” displays taken from magazines, technical digests, books, newspapers, and other sources. The talk will conclude with some reflections about ways in which computational systems can take advantage of these principles, for example by providing no more and no less information than is relevant to the viewer's immediate concerns.
Efficient cartogram generation: a comparison
Authors: Daniel A. Keim, Stephen C. North, Christian Panse, Jörn Schneidewind
Published at InfoVis, 2002

Cartograms are a well-known technique for showing geography-related statistical information, such as population demographics and epidemiological data. The basic idea is to distort a map by resizing its regions according to a statistical parameter, but in a way that keeps the map recognizable. We deal with the problem of making continuous cartograms that strictly retain the topology of the input mesh. We compare two algorithms to solve the continuous cartogram problem. The first one uses an iterative relocation of the vertices based on scanlines. The second one is based on the Gridfit technique, which uses pixel-based distortion based on a quadtree-like data structure.
Graphical encoding for information visualization: an empirical study
Authors: Lucy T. Nowell, Robert S. Schulman, Deborah Hix
Published at InfoVis, 2002

Research in several areas provides scientific guidance for use of graphical encoding to convey information in an information visualization display. By graphical encoding we mean the use of visual display elements such as icon color, shape, size, or position to convey information about objects represented by the icons. Literature offers inconclusive and often conflicting viewpoints, including the suggestion that the effectiveness of a graphical encoding depends on the type of data represented. Our empirical study suggests that the nature of the users' perceptual task is more indicative of the effectiveness of a graphical encoding than the type of data represented.
Interactive information visualization of a million items
Authors: Jean-Daniel Fekete, Catherine Plaisant
Published at InfoVis, 2002

Existing information visualization techniques are usually limited to the display of a few thousand items. This article describes new interactive techniques capable of handling a million items (effectively visible and manageable on screen). We evaluate the use of hardware-based techniques available with newer graphics cards, as well as new animation techniques and non-standard graphical features such as stereovision and overlap count. These techniques have been applied to two popular information visualizations: treemaps and scatter plot diagrams; but are generic enough to be applied to other 2D representations as well.
Internet traffic: visualization, discovery, and very large displays
Authors: William S. Cleveland
Published at InfoVis, 2002

For a decade, the ruling common wisdom for Internet traffic held that it was everywhere bursty: over periods lasting tens of milliseconds to hundreds, the traffic was either much below its average rate or much above. In other words, the traffic was not smooth, not staying at all times close to its average. It was bursty on the cable running down a street, carrying the merged traffic of a small number of cable modem users in one section of a town. It was bursty on the core fiber of an Internet service provider, carrying the merged traffic of thousands of users from all over the country. The Internet was designed to accommodate the bursty traffic. The routers and switches that forward traffic from one place to the next were designed for burstiness, and Internet service providers allocated traffic loads on the devices based on an assumption of burstiness. Recently, it was discovered that the old common wisdom is not true. Visualization played a fundamental role in the discovery. The old wisdom held up for links with a small numbers of users. But as the number of users increases, the burstiness dissipates, and the traffic becomes smooth. Design of the high-load part of the Internet needs to be rethought. The old wisdom had persisted for high-load links because the databases of traffic measurements from them are immense, and the traffic measurements had not been studied in their fullest detail, which is necessary to see the smoothing. Visualization tools allowed the detail to be seen, and allowed the verification of a mathematical theory that predicts the smoothing. To see the detail, individual visual displays were created that take up an amount of virtual screen real estate measured in hundreds of pages. It is a simple idea: if you have a lot of data, and you want to see it in detail, you need a lot of space. What is needed now is a rich set of ideas and methods for navigating such very large displays.
InterRing: an interactive tool for visually navigating and manipulating hierarchical structures
Authors: Jing Yang 0001, Matthew O. Ward, Elke A. Rundensteiner
Published at InfoVis, 2002

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.
Multiple foci drill-down through tuple and attribute aggregation polyarchies in tabular data
Authors: Nathan Conklin, Sandeep Prabhakar, Chris North 0001
Published at InfoVis, 2002

Information analysis often involves decomposing data into sub-groups to allow for comparison and identification of relationships. Breakdown Visualization provides a mechanism to support this analysis through user guided drill-down of polyarchical metadata. This metadata describes multiple hierarchical structures for organizing tuple aggregations and table attributes. This structure is seen in financial data, organizational structures, sport statistics, and other domains. A spreadsheet format enables comparison of visualizations at any level of the hierarchy. Breakdown Visualization allows users to drill-down a single hierarchy then pivot into another hierarchy within the same view. It utilizes a fix and move technique that allows users to select multiple foci for drill-down.
Multiscale visualization using data cubes
Authors: Chris Stolte, Diane Tang, Pat Hanrahan
Published at InfoVis, 2002

Most analysts start with an overview of the data before gradually refining their view to be more focused and detailed. Multiscale pan-and-zoom systems are effective because they directly support this approach. However generating abstract overviews of large data sets is difficult, and most systems take advantage of only one type of abstraction: visual abstraction. Furthermore, these existing systems limit the analyst to a single zooming path on their data and thus a single set of abstract views. This paper presents: (1) a formalism for describing multiscale visualizations of data cubes with both data and visual abstraction, and (2) a method for independently zooming along one or more dimensions by traversing a zoom graph with nodes at different levels of detail. As an example of how to design multiscale visualizations using our system, we describe four design patterns using our formalism. These design patterns show the effectiveness of multiscale visualization of general relational databases.
Process visualization with levels of detail
Authors: Kresimir Matkovic, Helwig Hauser, Reinhard Sainitzer, M. Eduard Gröller
Published at InfoVis, 2002

We demonstrate how we apply information visualization techniques to process monitoring. Virtual instruments are enhanced using history encoding instruments are capable of displaying the current value and the value from the near past. Multi-instruments are capable of displaying several data sources simultaneously. Levels of detail for virtual instruments are introduced where the screen area is inversely proportional to the information amount displayed. Furthermore the monitoring system is enhanced by using: 3D anchoring attachment of instruments to positions on a 3D model, collision avoidance a physically based spring model prevents instruments from overlapping, and focus+context rendering - giving the user a possibility to examine particular instruments in detail without loosing the context information.
SpaceTree: supporting exploration in large node link tree, design evolution and empirical evaluation
Authors: Catherine Plaisant, Jesse Grosjean, Benjamin B. Bederson
Published at InfoVis, 2002

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.
The illusion of perceived metric 3D structure
Authors: Mats Lind, Geoffrey P. Bingham, Camilla Forsell
Published at InfoVis, 2002

A large body of results on the characteristics of human spatial vision suggests that space perception is distorted. Recent studies indicate that the geometry of visual space is best understood as Affine. If this is the case, it has far reaching implications on how 3D visualizations can be successfully employed. For instance, all attempts to build visualization systems where users are expected to discover relations based on Euclidean distances or shapes will be ineffective. Because visualization can, and sometimes do, employ all possible types of depth information and because the results from vision research usually concentrates on one or two such types, three experiments were performed under near optimal viewing conditions. The aim of the experiments was twofold: To test whether the earlier findings generalize to optimal viewing conditions and to get a sense of the size of the error under such conditions. The results show that the findings do generalize and that the errors are large. The implications of these results for successful visualizations are discussed.
Visual path analysis
Authors: Alan Keahey, Stephen G. Eick
Published at InfoVis, 2002

We describe a system for analyzing the flow of traffic through Web sites. We decomposed the general path analysis problem into a set of distinct subproblems, and created a visual metaphor for analyzing each of them. Our system works off of multiple representations of the clickstream, and exposes the path extraction algorithms and data to the visual metaphors as Web services. We have combined the visual metaphors into a Web-based "path analysis portal" that lets the user easily switch between the different modes of analysis.
Visual unrolling of network evolution and the analysis of dynamic discourse
Authors: Ulrik Brandes, Steven R. Corman
Published at InfoVis, 2002

A new method for visualizing the class of incrementally evolving networks is presented. In addition to the intermediate states of the network it conveys the nature of the change between them by unrolling the dynamics of the network. Each modification is shown in a separate layer of a three-dimensional representation, where the stack of layers corresponds to a time line of the evolution. We focus on discourse networks as the driving application, but our method extends to any type of network evolving in similar ways.