DevLan/vispubs huggingface dataset:
Similarity clustering of dimensions for an enhanced visualization of multidimensional data
Authors: Mihael Ankerst, Stefan Berchtold, Daniel A. Keim
Published at InfoVis, 1998

The order and arrangement of dimensions (variates) is crucial for the effectiveness of a large number of visualization techniques such as parallel coordinates, scatterplots, recursive pattern, and many others. We describe a systematic approach to arrange the dimensions according to their similarity. The basic idea is to rearrange the data dimensions such that dimensions showing a similar behavior are positioned next to each other. For the similarity clustering of dimensions, we need to define similarity measures which determine the partial or global similarity of dimensions. We then consider the problem of finding an optimal one- or two-dimensional arrangement of the dimensions based on their similarity. Theoretical considerations show that both, the one- and the two-dimensional arrangement problem are surprisingly hard problems, i.e. they are NP complete. Our solution of the problem is therefore based on heuristic algorithms. An empirical evaluation using a number of different visualization techniques shows the high impact of our similarity clustering of dimensions on the visualization results.
The generalized detail in-context problem
Authors: Alan Keahey
Published at InfoVis, 1998

The paper describes a general formulation of the "detail-in-context" problem, which is a central issue of fundamental importance to a wide variety of nonlinear magnification systems. A number of tools are described for dealing with this problem effectively. These tools can be applied to any continuous nonlinear magnification system, and are not tied to specific implementation features of the system that produced the original transformation. Of particular interest is the development of "seamless multi level views", which allow multiple global views of an information space (each having different information content) to be integrated into a single view without discontinuity.
The shape of Shakespeare: visualizing text using implicit surfaces
Authors: Randall M. Rohrer, John L. Sibert, David S. Ebert
Published at InfoVis, 1998

Information visualization focuses on the use of visual means for exploring non-visual information. While free-form text is a rich, common source of information, visualization of text is a challenging problem since text is inherently non-spatial. The paper explores the use of implicit surface models for visualizing text. The authors describe several techniques for text visualization that aid in understanding document content and document relationships. A simple method is defined for mapping document content to shape. By comparing the shapes of multiple documents, global content similarities and differences may be noted. In addition, they describe a visual clustering method in which documents are arranged in 3D based upon similarity scoring. Documents deemed closely related blend together as a single connected shape. Hence, a document corpus becomes a collection of shapes that reflect inter-document relationships. These techniques provide methods to visualize individual documents as well as corpus meta-data. They then combine the two techniques to produce transparent clusters enclosing individual document shapes. This provides a way to visualize both local and global contextual information. Finally, they elaborate on several potential applications of these methods.
Traversal-based visualization of data structures
Authors: Jeffrey L. Korn, Andrew W. Appel
Published at InfoVis, 1998

Algorithm animation systems and graphical debuggers perform the task of translating program state into visual representations. While algorithm animations typically rely on user augmented source code to produce visualizations, debuggers make use of symbolic information in the target program. As a result, visualizations produced by debuggers often lack important semantic content, making them inferior to algorithm animation systems. The paper presents a method to provide higher level, more informative visualizations in a debugger using a technique called traversal based visualization. The debugger traverses a data structure using a set of user supplied patterns to identify parts of the data structure to be drawn a similar way. A declarative language is used to specify the patterns and the actions to take when the patterns are encountered. Alternatively, the user can construct traversal specifications through a graphical user interface to the declarative language. Furthermore, the debugger supports modification of data. Changes made to the on-screen representation are reflected in the underlying data.
Visualizing decision table classifiers
Authors: Barry G. Becker
Published at InfoVis, 1998

Decision tables, like decision trees or neural nets, are classification models used for prediction. They are induced by machine learning algorithms. A decision table consists of a hierarchical table in which each entry in a higher level table gets broken down by the values of a pair of additional attributes to form another table. The structure is similar to dimensional stacking. A visualization method is presented that allows a model based on many attributes to be understood even by those unfamiliar with machine learning. Various forms of interaction are used to make this visualization more useful than other static designs.
WEBPATH-a three dimensional Web history
Authors: Emmanuel Frécon, Gareth Smith
Published at InfoVis, 1998

A number of usability studies report that many users of the WWW cannot find pages already visited, additionally many users cannot visualise where they are, or where they have been browsing. Currently, readily available WWW browsers provide history mechanisms that offer little or no support in the presentation and manipulation of visited sites. Manipulation and presentation of usage data, such as a browse history has been used in a number of cases to aid users in searching for previously attained data, and to teach or assist other users in their browse or searching techniques. The paper presents a virtual reality (VR) based application to be used alongside traditional Web browsers, which provides them with a flexibly tailorable real time visualisation of their history.
DIVA: Exploratory Data Analysis with Multimedia Streams
Authors: Wendy E. Mackay, Michel Beaudouin-Lafon
Published at CHI, 1998

DIVA supports exploratory data analysis of multimedia streams, enabling users to visualize, explore and evaluate patterns in data that change over time. The underlying stream algebra provides the mathematical basis for operating on diverse kinds of streams. The streamer visualization technique provides a smooth transition between spatial and temporal views of the data. Mapping source and presentation streams into a two-dimensional space provides users with a direct manipulation, nontemporal interface for viewing and editing streams. DIVA was developed to help us analyze both qualitative and quantitative data collected in our research with French air traffic controllers, including video of controllers at work, audio records of telephone, radio and other conversations, output from tools such as RADAR, and coded logs based on our observations. Although our emphasis is on exploratory data analysis, DIVA's stream architecture should prove useful for a wide variety of multimedia applications.
Finding and Visualizing Inter-Site Clan Graphs
Authors: Loren G. Terveen, William C. Hill
Published at CHI, 1998

For many purposes, the Web page is too small a unit of interaction. Users often want to interact with larger-scale entities, particularly collections of topically related items. We report three innovations that address this user need. l We replaced the web page with the web sire as the basic unit of interaction and analysis* We defined a new information structure, the clan graph, that groups together sets of related sites. l We invented a new graph visualization, the auditorium visualization, that reveals important structural and content properties of sites within a clan graph. We have discovered interesting information that can be extracted from the structure of a clan graph. We can identify structurally important sites with many incoming or outgoing links. Lii between sites serve important functions: they often identify “f?ont door” pages of sites, sometimes identify especially significant pages within a site, and occasionally contain informative anchor text.
Information Archiving with Bookmarks: Personal Web Space Construction and Organization
Authors: David Abrams, Ronald Baecker, Mark H. Chignell
Published at CHI, 1998

Bookmarks are used as "personal Web information spaces" to help people remember and retrieve interesting Web pages. A study of personal Web information spaces surveyed 322 Web users and analyzed the bookmark archives of 50 Web users. The results of this study are used to address why people make bookmarks, and how they create, use, and organize them. Recommendations for improving the organization, visualization, representation, and integration of bookmarks are provided. The recommendations include simple mechanisms for filing bookmarks at creation time, the use of time-based visualizations with automated filters, the use of contextual information in representing bookmarks, and the combination of hierarchy formation and Web page authoring to aid in organizing and viewing bookmarks.
Visualizing the Evolution of Web Ecologies
Authors: Ed Huai-hsin Chi, James E. Pitkow, Jock D. Mackinlay, Peter Pirolli, Rich Gossweiler, Stuart K. Card
Published at CHI, 1998

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.
A comparison of normal estimation schemes
Authors: Torsten Möller, Raghu Machiraju, Klaus Mueller 0001, Roni Yagel
Published at Vis, 1997

The task of reconstructing the derivative of a discrete function is essential for its shading and rendering as well as being widely used in image processing and analysis. We survey the possible methods for normal estimation in volume rendering and divide them into two classes based on the delivered numerical accuracy. The three members of the first class determine the normal in two steps by employing both interpolation and derivative filters. Among these is a new method which has never been realized. The members of the first class are all equally accurate. The second class has only one member and employs a continuous derivative filter obtained through the analytic derivation of an interpolation filter. We use the new method to analytically compare the accuracy of the first class with that of the second. As a result of our analysis we show that even inexpensive schemes can in fact be more accurate than high order methods. We describe the theoretical computational cost of applying the schemes in a volume rendering application and provide guidelines for helping one choose a scheme for estimating derivatives. In particular we find that the new method can be very inexpensive and can compete with the normal estimations which pre-shade and pre-classify the volume (M. Levoy, 1988).
A topology modifying progressive decimation algorithm
Authors: William J. Schroeder
Published at Vis, 1997

Triangle decimation techniques reduce the number of triangles in a mesh, typically to improve interactive rendering performance or reduce data storage and transmission requirements. Most of these algorithms are designed to preserve the original topology of the mesh. Unfortunately, this characteristic is a strong limiting factor in overall reduction capability, since objects with a large number of holes or other topological constraints cannot be effectively reduced. The author presents an algorithm that yields a guaranteed reduction level, modifying topology as necessary to achieve the desired result. In addition, the algorithm is based on a fast local decimation technique, and its operations can be encoded for progressive storage, transmission, and reconstruction. He describes the new progressive decimation algorithm, introduces mesh splitting operations and shows how they can be encoded as a progressive mesh. He also demonstrates the utility of the algorithm on models ranging in size from 1,132 to 1.68 million triangles and reduction ratios of up to 200:1.
A visualization of music
Authors: Sean M. Smith, Glen N. Williams
Published at Vis, 1997

Currently, the most popular method of visualizing music is music notation. Through music notation, an experienced musician can gain an impression of how a particular piece of music sounds simply by looking at the notes on paper. However, most listeners are unfamiliar or uncomfortable with the complex nature of music notation. The goal of this project is to present an alternate method for visualizing music that makes use of color and 3D space. This paper describes one method of visualizing music in 3D space. The implementation of this method shows that music visualization is an effective technique, although it is certainly not the only possible method for accomplishing the task. Throughout the course of this project, several variations and alternative approaches were discussed. The final version of this project reflects the decisions that were made in order to present the best possible representation of music data.
Accelerated volume rendering using homogeneous region encoding
Authors: Jason Freund, Kenneth R. Sloan
Published at Vis, 1997

Previous accelerated volume rendering techniques have used auxiliary hierarchical datastructures to skip empty and homogeneous regions. Although some recent research has taken advantage of more efficient direct encoding techniques to skip empty regions, no work has been done to directly encode homogeneous but not empty regions. 3D distance transforms previously used to encode empty space can be extended to preprocess homogeneous regions as well, and these regions can be efficiently encoded and incorporated into volume ray-casting and back projection algorithms with a high degree of flexibility.
An anti-aliasing technique for splatting
Authors: J. Edward Swan II, Klaus Mueller 0001, Torsten Möller, Naeem Shareef, Roger Crawfis, Roni Yagel
Published at Vis, 1997

Splatting is a popular direct volume rendering algorithm. However, the algorithm does not correctly render cases where the volume sampling rate is higher than the image sampling rate (e.g. more than one voxel maps into a pixel). This situation arises with orthographic projections of high-resolution volumes, as well as with perspective projections of volumes of any resolution. The result is potentially severe spatial and temporal aliasing artifacts. Some volume ray-casting algorithms avoid these artifacts by employing reconstruction kernels which vary in width as the rays diverge. Unlike ray-casting algorithms, existing splatting algorithms do not have an equivalent mechanism for avoiding these artifacts. The authors propose such a mechanism, which delivers high-quality splatted images and has the potential for a very efficient hardware implementation.
An interactive cerebral blood vessel exploration system
Authors: Anna Puig, Dani Tost, Isabel Navazo
Published at Vis, 1997

An interactive cerebral blood vessel exploration system is described. It has been designed on the basis of neurosurgeons' requirements in order to assist them in the diagnosis of vascular pathologies. The system is based on the construction of a symbolic model of the vascular tree, with automatic identification and labelling of vessel bifurcations, aneurysms and stenoses. It provides several types of visualization: individual MRA (magnetic resonance angiography) slices, MIP (maximum intensity projection), shaded rendering, symbolic schemes and surface reconstruction.
Application-controlled demand paging for out-of-core visualization
Authors: Michael Cox, David Ellsworth
Published at Vis, 1997

In the area of scientific visualization, input data sets are often very large. In visualization of computational fluid dynamics (CFD) in particular, input data sets today can surpass 100 Gbytes, and are expected to scale with the ability of supercomputers to generate them. Some visualization tools already partition large data sets into segments, and load appropriate segments as they are needed. However, this does not remove the problem for two reasons: 1) there are data sets for which even the individual segments are too large for the largest graphics workstations, 2) many practitioners do not have access to workstations with the memory capacity required to load even a segment, especially since the state-of-the-art visualization tools tend to be developed by researchers with much more powerful machines. When the size of the data that must be accessed is larger than the size of memory, some form of virtual memory is simply required. This may be by segmentation, paging, or by paged segments. The authors demonstrate that complete reliance on operating system virtual memory for out-of-core visualization leads to egregious performance. They then describe a paged segment system that they have implemented, and explore the principles of memory management that can be employed by the application for out-of-core visualization. They show that application control over some of these can significantly improve performance. They show that sparse traversal can be exploited by loading only those data actually required.
Architectural walkthroughs using portal textures
Authors: Daniel G. Aliaga, Anselmo Lastra
Published at Vis, 1997

This paper outlines a method to dynamically replace portals with textures in a cell-partitioned model. The rendering complexity is reduced to the geometry of the current cell thus increasing interactive performance. A portal is a generalization of windows and doors. It connects two adjacent cells (or rooms). Each portal of the current cell that is some distance away from the viewpoint is rendered as a texture. The portal texture (smoothly) returns to geometry when the viewpoint gets close to the portal. This way all portal sequences (not too close to the viewpoint) have a depth complexity of one. The size of each texture and distance at which the transition occurs is configurable for each portal.
Auralization of streamline vorticity in computational fluid dynamics data
Authors: Christopher R. Volpe, Ephraim P. Glinert
Published at Vis, 1997

Presents a new method for auralization of the vorticity of a streamline in a vector field. This technique involves using a composite tone formed by superimposing sine waves of various amplitudes whose frequency and amplitude vary in such a way as to give the perception that the resulting sound increases or decreases endlessly in pitch without ever extending beyond the listener's range of audible frequencies. Continuous clockwise or counterclockwise rotations of a streamline resulting from vorticity can then be displayed aurally as an apparently continuous increase or decrease in pitch.
Brushing techniques for exploring volume datasets
Authors: Pak Chung Wong, R. Daniel Bergeron
Published at Vis, 1997

Describes several visualization techniques based on the notion of multi-resolution brushing to browse large 3D volume datasets. Our software is implemented using public-domain libraries, and is designed to run on average-equipped desktop computers such as a Linux machine with 32 MBytes of memory. Empirically, our system allows scientists to obtain information from a large dataset with over 8.3 million numbers in interactive time. We show that very large scientific volume datasets can be accessed and utilized without expensive hardware and software.
Building and traversing a surface at variable resolution
Authors: Leila De Floriani, Paola Magillo, Enrico Puppo
Published at Vis, 1997

The authors consider the multi-triangulation, a general model for representing surfaces at variable resolution based on triangle meshes. They analyse characteristics of the model that make it effective for supporting basic operations such as extraction of a surface approximation, and point location. An interruptible algorithm for extracting a representation at a resolution variable over the surface is presented. Different heuristics for building the model are considered and compared. Results on both the construction and the extraction algorithm are presented.
Case study: efficient visualization of physical and structural properties in crash-worthiness simulations
Authors: Sven Kuschfeldt, Thomas Ertl, Michael Holzner
Published at Vis, 1997

Numerical finite element simulations of the behaviour of a car body in frontal, side or rear impact collision scenarios have become increasingly complex as well as reliable and precise. They are well-established as a standard evaluation tool in the automotive development process. Both the increased complexity and the advances in computer graphics technology have resulted in the need for new visualization techniques to facilitate the analysis of the immense amount of data originating from such scientific engineering computations. Expanding the effectiveness of traditional post-processing techniques is one key to achieve shorter design cycles and faster time-to-market. In this paper, we describe how the extensive use of texture mapping and new visualization mappings like force tubing can considerably enhance the post-processing of structural and physical properties of car components in crash simulations. We show that, using these techniques, both the calculation costs and the rendering costs are reduced, and the quality of the visualization is improved.
Case study: visualizing customer segmentations produced by self organizing maps
Authors: Holly E. Rushmeier, Richard D. Lawrence, George S. Almási
Published at Vis, 1997

We describe a set of visualization programs developed for understanding segmentations of customer records produced by a self organizing map (SOM) algorithm. A SOM produces segments of similar customer records that can then be used as the basis of a marketing campaign. Since the characteristics that each segment will have in common are not specified a priori, visualization is essential to understanding the segment to design specific marketing strategies. Two different styles of visualizations were found to be useful for the two types of observers of the data. Abstract overviews of the entire segmentation were designed for analysts applying the SOM algorithm. Detailed scatterplots of individual records were designed for communicating the results to decision makers specifying marketing strategy.
Case study: wildfire visualization
Authors: James P. Ahrens, Patrick S. McCormick, James Bossert, Jon Reisner, Judith Winterkamp
Published at Vis, 1997

The ability to forecast the progress of crisis events would significantly reduce human suffering and loss of life, the destruction of property and expenditures for assessment and recovery. Los Alamos National Laboratory has established a scientific thrust in crisis forecasting to address this national challenge. In the initial phase of this project, scientists at Los Alamos are developing computer models to predict the spread of a wildfire. Visualization of the results of the wildfire simulation will be used by scientists to assess the quality of the simulation and eventually by fire personnel as a visual forecast of the wildfire's evolution. The fire personnel and scientists want the visualization to look as realistic as possible without compromising scientific accuracy. This paper describes how the visualization was created, analyzes the tools and approach that were used, and suggests directions for future work and research.