DevLan/vispubs huggingface dataset:
Visualizing usability log data
Authors: Mark Gray, Albert N. Badre, Mark Guzdial
Published at InfoVis, 1996

Our approach to testing graphical user interfaces involves logging large amounts of data. These logs capture information at the key press and mouse click level about how an application is used. Since the raw data is voluminous and not at a useful level of detail, we use analysis and visualization to find information that is interesting and useful to a usability analyst but was previously buried in the data. We call some of our custom visualizations "contextual" meaning they use key elements of the context the data was collected in as an organizing structure. We expect this type of visualization to be easier and faster to understand and more helpful than traditional charts. We hope that our finding a natural geometry for these visualizations will inspire others whose data apparently has no inherent geometry to find natural ways to visualize their data.
Externalising Abstract Mathematical Models
Authors: Lisa Tweedie, Robert Spence, Huw Dawkes, Hua Su
Published at CHI, 1996

Abstract mathematical models play an important part in engineering design, economic decision making and other activities. Such models can be externalised in the form of Interactive Visualisation Artifacts (IVAs). These IVAs display the data generated by mathematical models in simple graphs which are interactively linked. Visual examination of these graphs enables users to acquire insight into the complex relations embodied in the model. In the engineering context this insight can be exploited to aid design. The paper describes two IVAs for engineering design: The Influence Explorer and The Prosection Matrix. Formative evaluation studies are briefly discussed.
Interaction Design and Human Factors Support in the Development of a Personal Communicator for Children
Authors: Ron Oosterholt, Mieko Kusano, Govert de Vries
Published at CHI, 1996

Today's computer games for children are primarily focused on boys. Two years ago Philips started the development of a new 'personal communication' product that addresses the needs of young children and especially the needs of young gifts. This article is focused on the interaction design and human factors support provided throughout the development of this product. It illustrates the involvement of the interaction design discipline, ranging from the initial generation and visualization of interface ideas to the final transfer to the software engineering team of detailed user interface specifications. The article also describes how human factors support ensured that potential users were involved on continuously in the design process, as well' as how this involvement influenced the development of the final product. The article concludes with a discussion of the lessons learned in designing products for children.
LifeLines: Visualizing Personal Histories
Authors: Catherine Plaisant, Brett Milash, Anne Rose, Seth Widoff, Ben Shneiderman
Published at CHI, 1996

LifeLines provide a general visualization environment for personal histories that can be applied to medical and court records, professional histories and other types of biographical data. A one screen overview shows multiple facets of the records. Aspects, for example medical conditions or legal cases, are displayed as individual time lines, while icons indicate discrete events, such as physician consultations or legal reviews. Line color and thickness illustrate relationships or significance, rescaling tools and filters allow users to focus on part of the information. LifeLines reduce the chances of missing information, facilitate spotting anomalies and trends, streamline access to details, while remaining tailorable and easily transferable between applications. The paper describes the use of LifeLines for youth records of the Maryland Department of Juvenile Justice and also for medical records. User's feedback was collected using a Visual Basic prototype for the youth record. Techniques to deal with complex records are reviewed and issues of a standard personal record format are discussed.
Multiagent Model of Dynamic Design: Visualization as an Emergent Behavior of Active Design Agents
Authors: Suguru Ishizaki
Published at CHI, 1996

This research has been motivated by the lack of models and languages in the visual design field that are able to address design solutions, which continuously adapt in response to the dynamic changes both in the information itself and in the goals or intentions of the information recipient. This paper postulates a muhiagent model of dynamic design--a theoretical framework of design that provides a model with which the visual designer can think during the course of designing. The model employs a decentralized model of design as a premise, and borrows its conceptual model from the improvisational performance, such as dance and music, and bases its theoretical and technical framework on the field of multiagent systems. A design solution is considered an emergent behavior of a collection of active design agents, or performers, each of which is responsible for presenting a particular segment of information. The graphical behaviors of design agents are described by their dynamic activities--rather than by the traditional method of fixed attributes. The model is illustrated with two design projects, Dynamic News Display System and E-Mail Display, both of which were implemented using a multiagent design simulation system, perform, along with an agent description language, persona.
Silk from a Sow's Ear: Extracting Usable Structures from the Web
Authors: Peter Pirolli, James E. Pitkow, Ramana Rao
Published at CHI, 1996

In its current implementation, the World-Wide Web lacks much of the explicit structure and strong typing found in many closed hypertext systems. While this property probably relates to the explosive acceptance of the Web, it further complicates the already difficult problem of identifying usable structures and aggregates in large hypertext collections. These reduced structures, or localities, form the basis for simplifying visualizations of and navigation through complex hypertext systems. Much of the previous research into identifying aggregates utilize graph theoretic algorithms based upon structural topology, i.e., the linkages between items. Other research has focused on content analysis to form document collections. This paper presents our exploration into techniques that utilize both the topology and textual similarity between items as well as usage data collected by servers and page meta-information lke title and size. Linear equations and spreading activation models are employed to arrange Web pages based upon functional categories, node types, and relevancy.
3D computational steering with parametrized geometric objects
Authors: Jurriaan D. Mulder, Jarke J. van Wijk
Published at Vis, 1995

Computational steering is the ultimate goal of interactive simulation: researchers change parameters of their simulation and immediately receive feedback on the effect. We present a general and flexible graphics tool that is part of an environment for computational steering developed at CWI. It enables the researcher to interactively develop his own interface with the simulation. This interface is constructed with 3D parametrized geometric objects. The properties of the objects are parametrized to output data and input parameters of the simulation. The objects visualize the output of the simulation, while the researcher can steer the simulation by direct manipulation of the objects. Several applications of 3D computational steering are presented.
A hardware acceleration method for volumetric ray tracing
Authors: Lisa M. Sobierajski, Ricardo S. Avila
Published at Vis, 1995

We present an acceleration method for volumetric ray tracing which utilizes standard graphics hardware without compromising image accuracy. The graphics hardware is employed to identify those segments of each ray that could possibly contribute to the final image. A volumetric ray tracing algorithm is then used to compute the final image, traversing only the identified segments of the rays. This technique can be used to render volumetric isosurfaces as well as translucent volumes. In addition, this method can accelerate the traversal of shadow rays when performing recursive ray tracing.
A model and a system for data-parallel program visualization
Authors: Thomas A. Wagner, R. Daniel Bergeron
Published at Vis, 1995

Parallel program visualization and debugging require new techniques for gathering and displaying execution trace and profile data. Interaction with the program during execution is also required to facilitate parallel debugging. We discuss the difficulties associated with runtime user/program interaction and how the data-parallel programming paradigm facilitates much more liberal runtime interaction than typical MIMD-based models. We present a model for data-parallel program visualization that addresses both data collection/interaction and visualization issues. We follow our model presentation with the design and implementation of a subset of our visualization model. We discuss our preliminary findings and propose future research directions.
A rule-based tool for assisting colormap selection
Authors: Lawrence D. Bergman, Bernice E. Rogowitz, Lloyd Treinish
Published at Vis, 1995

The paper presents an interactive approach for guiding the user's select of colormaps in visualization. PRAVDAColor, implemented as a module in the IBM Visualization Data Explorer, provides the user a selection of appropriate colormaps given the data type and spatial frequency, the user's task, and properties of the human perceptual system.
A visualization tool for studying the development of the moss Physcomitrella patens
Authors: F. David Fracchia, Neil W. Ashton
Published at Vis, 1995

The investigation of mechanisms responsible for the morphogenesis of complex biological organisms is an important area in biology. P. patens is an especially suitable plant for this research because it is a rather simple organism, facilitating its observation, yet it possesses developmental phenomena analogous to those which occur in higher plants, allowing the extrapolation of hypotheses to more complex organisms. The visualization consists of three components: biological data collection, computer-modelling (using L-systems), and model verification. The simulated developmental process is quite realistic and provides an excellent means for verifying the underlying hypotheses of morphogenesis.
An architecture for retaining and analyzing visual explorations of databases
Authors: John Peter Lee, Georges G. Grinstein
Published at Vis, 1995

A software architecture is presented to integrate a database management system with data visualization. One of its primary objectives, the retention of user-data interactions, is detailed. By storing all queries over the data along with high-level descriptions of the query results and the associated visualization, the processes by which a database is explored can be analyzed. This approach can lead to important contributions in the development of user models as "data explorers", metadata models for scientific databases, intelligent assistants and data exploration services. We describe the underlying elements of this approach, specifically the visual database exploration model and the metadata objects that support the model.
An extended data-flow architecture for data analysis and visualization
Authors: Greg Abram, Lloyd Treinish
Published at Vis, 1995

Modular visualization environments utilizing a data-flow execution model have become quite popular in recent years, especially those that incorporate visual programming tools. However, simplistic implementations of such an execution model are quite limited when applied to problems of realistic complexity, which negate the intuitive advantage of data-flow systems. This situation can be resolved by extending the execution model to incorporate a more complete and efficient programming infrastructure while still preserving the virtues of pure "data-flow". This approach has been used for the implementation of a general-purpose software package, IBM Visualization Data Explorer.
An illustrated analysis of sonification for scientific visualisation
Authors: Rosane Minghim, A. Robin Forrest
Published at Vis, 1995

This paper presents an analysis of progress in the use of sound as a tool in support of visualisation and gives an insight into its development and future needs. Special emphasis is given to the use of sound in scientific and engineering applications. A system developed to support surface data presentation and interaction by using sound is presented and discussed.
Astronomers and their shady algorithms
Authors: Richard Gooch
Published at Vis, 1995

The vast quantities of data which may be produced by modern radio telescopes have outstripped conventional visualisation techniques available to astronomers. While research in other areas of visualisation finds some application in astronomy, problems peculiar to the field require new techniques. This paper presents a brief overview of some of the problems of visualisation for astronomy and compares different shading algorithms. A more comprehensive overview may be found in Norris (1994) and Gooch (1995).
Authenticity analysis of wavelet approximations in visualization
Authors: Pak Chung Wong, R. Daniel Bergeron
Published at Vis, 1995

Wavelet transforms include data decompositions and reconstructions. This paper is concerned with the authenticity issues of the data decomposition, particularly for data visualization. A total of six datasets are used to clarify the approximation characteristics of compactly supported orthogonal wavelets. We present an error tracking mechanism, which uses the available wavelet resources to measure the quality of the wavelet approximations.
Automated generation of visual simulation databases using remote sensing and GIS
Authors: Martin Suter, Daniel Nüesch
Published at Vis, 1995

This paper reports on the development of a strategy to generate databases used for real-time interactive landscape visualization. The database construction from real world data is intended to be as automated as possible. The primary sources of information are remote sensing imagery recorded by Landsat's Thematic Mapper (TM) and digital elevation models (DEM). Additional datasets (traffic networks and buildings) are added to extend the database. In a first step the TM images are geocoded and then segmented into areas of different land coverage. During the visual simulation highly detailed photo textures are applied onto the terrain based on the classification results to increase the apparent amount of detail. The data processing and integration is carried out using custom image processing and geographic information systems (GIS) software. Finally, a sample visual simulation application is implemented. Emphasis is put on practical implementation to test the feasibility of the approach as a whole.
Automatic generation of triangular irregular networks using greedy cuts
Authors: Cláudio T. Silva, Joseph S. B. Mitchell, Arie E. Kaufman
Published at Vis, 1995

Proposes a new approach to the automatic generation of triangular irregular networks (TINs) from dense terrain models. We have developed and implemented an algorithm based on the greedy principle used to compute minimum-link paths in polygons. Our algorithm works by taking greedy cuts ("bites") out of a simple closed polygon that bounds the yet-to-be triangulated region. The algorithm starts with a large polygon, bounding the whole extent of the terrain to be triangulated, and works its way inward, performing at each step one of three basic operations: ear cutting, greedy biting, and edge splitting. We give experimental evidence that our method is competitive with current algorithms and has the potential to be faster and to generate many fewer triangles. Also, it is able to keep the structural terrain fidelity at almost no extra cost in running time and it requires very little memory beyond that for the input height array.
Case study: an integrated approach for steering, visualization, and analysis of atmospheric simulations
Authors: Yves Jean, Thomas Kindler, William Ribarsky, Weiming Gu, Greg Eisenhauer, Karsten Schwan, Fred Alyea
Published at Vis, 1995

In the research described, we have constructed a tightly coupled set of methods for monitoring, steering, and applying visual analysis to large scale simulations. The work shows how a collaborative, interdisciplinary process that teams application and computer scientists can result in a powerful integrated approach. The integrated design allows great flexibility in the development and use of analysis tools. The work also shows that visual analysis is a necessary component for full understanding of spatially complex, time dependent atmospheric processes.
Case study: using spatial access methods to support the visualization of environmental data
Authors: Charles Falkenberg, Ravi Kulkarni
Published at Vis, 1995

As part of a large effort evaluating the effect of the Exxon Valdez oil spill, we are using the spatial selection features of an object relational database management system to support the visualization of the ecological data. The effort, called the Sound Ecosystem Assessment project (SEA), is collecting and analyzing oceanographic and biological data from Prince William Sound in Alaska. To support visualization of the SEA data we are building a data management system which includes a spatial index over a bounding polygon for all of the datasets which are collected. In addition to other selection criteria the prototype provides several methods for selecting data within an arbitrary region. This case study presents the requirements and the implementation for the application prototype which combines visualization and database technology. The spatial indexing features of the Illustra object relational database management system are linked with the visualization capabilities of AVS to create an interactive environment for analysis of SEA data.
Compression domain rendering of time-resolved volume data
Authors: Rüdiger Westermann
Published at Vis, 1995

An important challenge in the visualization of three-dimensional volume data is the efficient processing and rendering of time-resolved sequences. Only the use of compression techniques, which allow the reconstruction of the original domain from the compressed one locally, makes it possible to evaluate these sequences in their entirety. In this paper, a new approach for the extraction and visualization of so-called time features from within time-resolved volume data is presented. Based on the asymptotic decay of multiscale representations of spatially localized time evolutions of the data, singular points can be discriminated. Also, the corresponding Lipschitz exponents, which describe the signals' local regularity, can be determined, and can be taken as a measure of the variation in time. The compression ratio and the comprehension of the underlying signal is improved if we first restore the extracted regions which contain the most important information.
Defining, computing, and visualizing molecular interfaces
Authors: Amitabh Varshney, Frederick P. Brooks Jr., David C. Richardson, William V. Wright, Dinesh Manocha
Published at Vis, 1995

A parallel, analytic approach for defining and computing the inter and intra molecular interfaces in three dimensions is described. The molecular interface surfaces are derived from approximations to the power diagrams over the participating molecular units. For a given molecular interface our approach can generate a family of interface surfaces parametrized by /spl alpha/ and /spl beta/, where /spl alpha/ is the radius of the solvent molecule (also known as the probe radius) and /spl beta/ is the interface radius that defines the size of the molecular interface. Molecular interface surfaces provide biochemists with a powerful tool to study surface complementarity and to efficiently characterize the interactions during a protein substrate docking. The complexity of our algorithm for molecular environments is O(nk log/sup 2/ k), where n is the number of atoms in the participating molecular units and k is the average number of neighboring atoms-a constant, given /spl alpha/ and /spl beta/.
Direct rendering of Laplacian pyramid compressed volume data
Authors: Mohammad H. Ghavamnia, Xue D. Yang
Published at Vis, 1995

Volume rendering generates 2D images by ray tracing 3D volume data. This technique imposes considerable demands on storage space as the data set grows in size. In this paper, we describe a method to render compressed volume data directly to reduce the memory requirements of the rendering process. The volume data was compressed by a technique called the Laplacian pyramid. A compression ratio of 10:1 was achieved by uniform quantization over the Laplacian pyramid. The quality of the images obtained by this technique as virtually indistinguishable from that of the images generated from the uncompressed volume data. A significant improvement in computational performance was achieved by using a cache algorithm to temporarily retain the reconstructed voxels to be used by the adjacent rays.
Enhanced spot noise for vector field visualization
Authors: Wim C. de Leeuw, Jarke J. van Wijk
Published at Vis, 1995

Spot noise is a technique for texture synthesis, which is very useful for vector field visualization. This paper describes improvements and extensions of the basic principle of spot noise. First, better visualization of highly curved vector fields with spot noise is achieved, by adapting the shape of the spots to the local velocity field. Second, filtering of spots is proposed to eliminate undesired low frequency components from the spot noise texture. Third, methods are described to utilize graphics hardware to generate the texture, and to produce variable viewpoint animations of spot noise on surfaces. Fourth, the synthesis of spot noise on grids with highly irregular cell sizes is described.
Enhancing transparent skin surfaces with ridge and valley lines
Authors: Victoria Interrante, Henry Fuchs, Stephen M. Pizer
Published at Vis, 1995

There are many applications that can benefit from the simultaneous display of multiple layers of data. The objective in these cases is to render the layered surfaces in a such way that the outer structures can be seen and seen through at the same time. The paper focuses on the particular application of radiation therapy treatment planning, in which physicians need to understand the three dimensional distribution of radiation dose in the context of patient anatomy. We describe a promising technique for communicating the shape and position of the transparent skin surface while at the same time minimally occluding underlying isointensity dose surfaces and anatomical objects: adding a sparse, opaque texture comprised of a small set of carefully chosen lines. We explain the perceptual motivation for explicitly drawing ridge and valley curves on a transparent surface, describe straightforward mathematical techniques for detecting and rendering these lines, and propose a small number of reasonably effective methods for selectively emphasizing the most perceptually relevant lines in the display.