Conference stringclasses 6 values | Year int64 1.99k 2.03k | Title stringlengths 8 187 | DOI stringlengths 16 32 | Abstract stringlengths 128 7.15k ⌀ | Accessible bool 2 classes | Early bool 2 classes | AuthorNames-Deduped listlengths 1 24 | Award listlengths 0 2 | Resources listlengths 0 5 | ResourceLinks listlengths 0 10 |
|---|---|---|---|---|---|---|---|---|---|---|
VAST | 2,007 | VAST to Knowledge: Combining tools for exploration and mining | 10.1109/VAST.2007.4389015 | The investigation of the VAST Contest collection provided a valuable test for text mining techniques. Our group has focused on creating analytical tools to unveil relevant patterns and to aid with the content navigation in such text collections. Our results show how such an approach, in combination with visualization techniques, can ease the discovery process especially when multiple tools founded on the same approach to data mining are used in complement to and in concert with one another. | false | false | [
"Loretta Auvil",
"Xavier Llorà",
"Duane Searsmith",
"Kelly Searsmith"
] | [] | [] | [] |
VAST | 2,007 | VAST to Knowledge: Combining tools for exploration and mining | 10.1109/VAST.2007.4389035 | The investigation of the VAST Contest collection provided a valuable test for text mining techniques. Our group has focused on creating analytical tools to unveil relevant patterns and to aid with the content navigation in such text collections. Our results show how such an approach, in combination with visualization techniques, can ease the discovery process especially when multiple tools founded on the same approach to data mining are used in complement to and in concert with one another. | false | false | [
"Loretta Auvil",
"Xavier Llorà",
"Duane Searsmith",
"Kelly Searsmith"
] | [] | [] | [] |
VAST | 2,007 | VisPad: Integrating Visualization, Navigation and Synthesis | 10.1109/VAST.2007.4389021 | We present a new framework - VisPad - to support the user to revisit the visual exploration process, and to synthesize and disseminate information. It offers three integrated views. The data view allows the user to interactively explore the data. The navigation view captures the exploration process. It enables the user to revisit any particular state and reuse it. The knowledge view enables the user to record his/her findings and the relations between these findings. | false | false | [
"Yedendra Babu Shrinivasan",
"Jarke J. van Wijk"
] | [] | [] | [] |
VAST | 2,007 | Visual Analysis of Controversy in User-generated Encyclopedias | 10.1109/VAST.2007.4389012 | Wikipedia is a large and rapidly growing Web-based collaborative authoring environment, where anyone on the Internet can create, modify, and delete pages about encyclopedic topics. A remarkable property of some Wikipedia pages is that they are written by up to thousands of authors who may have contradicting opinions. In this paper we show that a visual analysis of the "who revises whom"- network gives deep insight into controversies. We propose a set of analysis and visualization techniques that reveal the dominant authors of a page, the roles they play, and the alters they confront. Thereby we provide tools to understand how Wikipedia authors collaborate in the presence of controversy. | false | false | [
"Ulrik Brandes",
"Jürgen Lerner"
] | [] | [] | [] |
VAST | 2,007 | Visual Analysis of Dynamic Networks with Geological Clustering | 10.1109/VAST.2007.4389027 | Many dynamic networks have associated geological information. Here we present two complementing visual analysis methods for such networks. The first one provides an overview with summerized information while the second one presents a more detailed view. The geological information is encoded in the network layout, which is designed to help maintain user's mental map. We also combined visualization with social network analysis to facilitate knowledge discovery, especially to understand network changes in the context overall evolution. Both methods are applied to the "History of the FIFA World Cup Competition" data set. | false | false | [
"Adel Ahmed",
"Xiaoyan Fu",
"Seok-Hee Hong 0001",
"Quan Hoang Nguyen",
"Kai Xu 0003"
] | [] | [] | [] |
VAST | 2,007 | Visual Analytics Approach to User-Controlled Evacuation Scheduling | 10.1109/VAST.2007.4388995 | Application of the ideas of visual analytics is a promising approach to supporting decision making, in particular, where the problems have geographic (or spatial) and temporal aspects. Visual analytics may be especially helpful in time-critical applications, which pose hard challenges to decision support. We have designed a suite of tools to support transportation-planning tasks such as emergency evacuation of people from a disaster- affected area. The suite combines a tool for automated scheduling based on a genetic algorithm with visual analytics techniques allowing the user to evaluate tool results and direct its work. A transportation schedule, which is generated by the tool, is a complex construct involving geographical space, time, and heterogeneous objects (people and vehicles) with states and positions varying in time. We apply task-analytical approach to design techniques that could effectively support a human planner in the analysis of this complex information H. 1.2 [User/Machine Systems]: Human information processing - Visual Analytics; 1.6.9 [Visualization]: information visualization. | false | false | [
"Gennady L. Andrienko",
"Natalia V. Andrienko",
"Ulrich Bartling"
] | [] | [] | [] |
VAST | 2,007 | Visual Analytics on Mobile Devices for Emergency Response | 10.1109/VAST.2007.4388994 | Using mobile devices for visualization provides a ubiquitous environment for accessing information and effective decision making. These visualizations are critical in satisfying the knowledge needs of operators in areas as diverse as education, business, law enforcement, protective services, medical services, scientific discovery, and homeland security. In this paper, we present an efficient and interactive mobile visual analytic system for increased situational awareness and decision making in emergency response and training situations. Our system provides visual analytics with locational scene data within a simple interface tailored to mobile device capabilities. In particular, we focus on processing and displaying sensor network data for first responders. To verify our system, we have used simulated data of The Station nightclub fire evacuation. | false | false | [
"SungYe Kim",
"Yun Jang",
"Angela K. Mellema",
"David S. Ebert",
"Timothy W. Collins"
] | [] | [] | [] |
VAST | 2,007 | Visual Analytics with Jigsaw | 10.1109/VAST.2007.4389017 | This article briefly introduces the Jigsaw system and describes how we used it in analysis activities for the VAST '07 Contest. Jigsaw is a visual analytic system that provides multiple coordinated views to show connections between entities that are extracted from a collection of documents. | false | false | [
"Carsten Görg",
"Zhicheng Liu",
"Neel Parekh",
"Kanupriya Singhal",
"John T. Stasko"
] | [] | [] | [] |
VAST | 2,007 | WireVis: Visualization of Categorical, Time-Varying Data From Financial Transactions | 10.1109/VAST.2007.4389009 | Large financial institutions such as Bank of America handle hundreds of thousands of wire transactions per day. Although most transactions are legitimate, these institutions have legal and financial obligations in discovering those that are suspicious. With the methods of fraudulent activities ever changing, searching on predefined patterns is often insufficient in detecting previously undiscovered methods. In this paper, we present a set of coordinated visualizations based on identifying specific keywords within the wire transactions. The different views used in our system depict relationships among keywords and accounts over time. Furthermore, we introduce a search-by-example technique which extracts accounts that show similar transaction patterns. In collaboration with the Anti-Money Laundering division at Bank of America, we demonstrate that using our tool, investigators are able to detect accounts and transactions that exhibit suspicious behaviors. | false | false | [
"Remco Chang",
"Mohammad Ghoniem",
"Robert Kosara",
"William Ribarsky",
"Jing Yang 0001",
"Evan A. Suma",
"Caroline Ziemkiewicz",
"Daniel A. Kern",
"Agus Sudjianto"
] | [] | [] | [] |
InfoVis | 2,007 | A Taxonomy of Clutter Reduction for Information Visualisation | 10.1109/TVCG.2007.70535 | Information visualisation is about gaining insight into data through a visual representation. This data is often multivariate and increasingly, the datasets are very large. To help us explore all this data, numerous visualisation applications, both commercial and research prototypes, have been designed using a variety of techniques and algorithms. Whether they are dedicated to geo-spatial data or skewed hierarchical data, most of the visualisations need to adopt strategies for dealing with overcrowded displays, brought about by too much data to fit in too small a display space. This paper analyses a large number of these clutter reduction methods, classifying them both in terms of how they deal with clutter reduction and more importantly, in terms of the benefits and losses. The aim of the resulting taxonomy is to act as a guide to match techniques to problems where different criteria may have different importance, and more importantly as a means to critique and hence develop existing and new techniques. | false | false | [
"Geoffrey P. Ellis",
"Alan J. Dix"
] | [] | [] | [] |
InfoVis | 2,007 | AdaptiviTree: Adaptive Tree Visualization for Tournament-Style Brackets | 10.1109/TVCG.2007.70537 | 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. | false | false | [
"Desney S. Tan",
"Greg Smith",
"Bongshin Lee",
"George G. Robertson"
] | [] | [] | [] |
InfoVis | 2,007 | Animated Transitions in Statistical Data Graphics | 10.1109/TVCG.2007.70539 | In this paper we investigate the effectiveness of animated transitions between common statistical data graphics such as bar charts, pie charts, and scatter plots. We extend theoretical models of data graphics to include such transitions, introducing a taxonomy of transition types. We then propose design principles for creating effective transitions and illustrate the application of these principles in <i>DynaVis</i>, a visualization system featuring animated data graphics. Two controlled experiments were conducted to assess the efficacy of various transition types, finding that animated transitions can significantly improve graphical perception. | false | false | [
"Jeffrey Heer",
"George G. Robertson"
] | [] | [] | [] |
InfoVis | 2,007 | Browsing Zoomable Treemaps: Structure-Aware Multi-Scale Navigation Techniques | 10.1109/TVCG.2007.70540 | 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. | false | false | [
"Renaud Blanch",
"Eric Lecolinet"
] | [] | [] | [] |
InfoVis | 2,007 | Casual Information Visualization: Depictions of Data in Everyday Life | 10.1109/TVCG.2007.70541 | Information visualization has often focused on providing deep insight for expert user populations and on techniques for amplifying cognition through complicated interactive visual models. This paper proposes a new subdomain for infovis research that complements the focus on analytic tasks and expert use. Instead of work-related and analytically driven infovis, we propose casual information visualization (or casual infovis) as a complement to more traditional infovis domains. Traditional infovis systems, techniques, and methods do not easily lend themselves to the broad range of user populations, from expert to novices, or from work tasks to more everyday situations. We propose definitions, perspectives, and research directions for further investigations of this emerging subfield. These perspectives build from ambient information visualization (Skog et al., 2003), social visualization, and also from artistic work that visualizes information (Viegas and Wattenberg, 2007). We seek to provide a perspective on infovis that integrates these research agendas under a coherent vocabulary and framework for design. We enumerate the following contributions. First, we demonstrate how blurry the boundary of infovis is by examining systems that exhibit many of the putative properties of infovis systems, but perhaps would not be considered so. Second, we explore the notion of insight and how, instead of a monolithic definition of insight, there may be multiple types, each with particular characteristics. Third, we discuss design challenges for systems intended for casual audiences. Finally we conclude with challenges for system evaluation in this emerging subfield. | false | false | [
"Zachary Pousman",
"John T. Stasko",
"Michael Mateas"
] | [] | [] | [] |
InfoVis | 2,007 | Exploring Multiple Trees through DAG Representations | 10.1109/TVCG.2007.70556 | We present a directed acyclic graph visualisation designed to allow interaction with a set of multiple classification trees, specifically to find overlaps and differences between groups of trees and individual trees. The work is motivated by the need to find a representation for multiple trees that has the space-saving property of a general graph representation and the intuitive parent-child direction cues present in individual representation of trees. Using example taxonomic data sets, we describe augmentations to the common barycenter DAG layout method that reveal shared sets of child nodes between common parents in a clearer manner. Other interactions such as displaying the multiple ancestor paths of a node when it occurs in several trees, and revealing intersecting sibling sets within the context of a single DAG representation are also discussed. | false | false | [
"Martin Graham 0001",
"Jessie Kennedy"
] | [] | [] | [] |
InfoVis | 2,007 | Geographically Weighted Visualization: Interactive Graphics for Scale-Varying Exploratory Analysis | 10.1109/TVCG.2007.70558 | We introduce a series of geographically weighted (GW) interactive graphics, or geowigs, and use them to explore spatial relationships at a range of scales. We visually encode information about geographic and statistical proximity and variation in novel ways through <i>gw-choropleth maps</i>, multivariate <i>gw-boxplots, gw-shading</i> and <i>scalograms</i>. The new graphic types reveal information about GW statistics at several scales concurrently. We impement these views in prototype software containing dynamic links and GW interactions that encourage exploration and refine them to consider directional geographies. An informal evaluation uses interactive GW techniques to consider Guerry's dataset of 'moral statistics', casting doubt on correlations originally proposed through visual analysis, revealing new local anomalies and suggesting multivariate geographic relationships. Few attempts at visually synthesising geography with multivariate statistical values at multiple scales have been reported. The <i>geowigs </i>proposed here provide informative representations of multivariate local variation, particularly when combined with interactions that coordinate views and result in <i>gw-shading</i>. We argue that they are widely applicable to area and point-based geographic data and provide a set of methods to support visual analysis using GW statistics through which the effects of geography can be explored at multiple scales. | false | false | [
"Jason Dykes",
"Chris Brunsdon"
] | [] | [] | [] |
InfoVis | 2,007 | Hotmap: Looking at Geographic Attention | 10.1109/TVCG.2007.70561 | Understanding how people use online maps allows data acquisition teams to concentrate their efforts on the portions of the map that are most seen by users. Online maps represent vast databases, and so it is insufficient to simply look at a list of the most-accessed URLs. Hotmap takes advantage of the design of a mapping system's imagery pyramid to superpose a heatmap of the log files over the original maps. Users' behavior within the system can be observed and interpreted. This paper discusses the imagery acquisition task that motivated Hotmap, and presents several examples of information that Hotmap makes visible. We discuss the design choices behind Hotmap, including logarithmic color schemes; low-saturation background images; and tuning images to explore both infrequently-viewed and frequently-viewed spaces. | false | false | [
"Danyel Fisher"
] | [] | [] | [] |
InfoVis | 2,007 | Interactive Tree Comparison for Co-located Collaborative Information Visualization | 10.1109/TVCG.2007.70568 | In many domains, increased collaboration has lead to more innovation by fostering the sharing of knowledge, skills, and ideas. Shared analysis of information visualizations does not only lead to increased information processing power, but team members can also share, negotiate, and discuss their views and interpretations on a dataset and contribute unique perspectives on a given problem. Designing technologies to support collaboration around information visualizations poses special challenges and relatively few systems have been designed. We focus on supporting small groups collaborating around information visualizations in a co-located setting, using a shared interactive tabletop display. We introduce an analysis of challenges and requirements for the design of co-located collaborative information visualization systems. We then present a new system that facilitates hierarchical data comparison tasks for this type of collaborative work. Our system supports multi-user input, shared and individual views on the hierarchical data visualization, flexible use of representations, and flexible workspace organization to facilitate group work around visualizations. | false | false | [
"Petra Isenberg",
"Sheelagh Carpendale"
] | [] | [] | [] |
InfoVis | 2,007 | Interactive Visual Exploration of a Large Spatio-temporal Dataset: Reflections on a Geovisualization Mashup. | 10.1109/TVCG.2007.70570 | Exploratory visual analysis is useful for the preliminary investigation of large structured, multifaceted spatio-temporal datasets. This process requires the selection and aggregation of records by time, space and attribute, the ability to transform data and the flexibility to apply appropriate visual encodings and interactions. We propose an approach inspired by geographical 'mashups' in which freely-available functionality and data are loosely but flexibly combined using de facto exchange standards. Our case study combines MySQL, PHP and the LandSerf GIS to allow Google Earth to be used for visual synthesis and interaction with encodings described in KML. This approach is applied to the exploration of a log of 1.42 million requests made of a mobile directory service. Novel combinations of interaction and visual encoding are developed including spatial 'tag clouds', 'tag maps', 'data dials' and multi-scale density surfaces. Four aspects of the approach are informally evaluated: the visual encodings employed, their success in the visual exploration of the dataset, the specific tools used and the 'mashup' approach. Preliminary findings will be beneficial to others considering using mashups for visualization. The specific techniques developed may be more widely applied to offer insights into the structure of multifarious spatio-temporal data of the type explored here. | false | false | [
"Jo Wood",
"Jason Dykes",
"Aidan Slingsby",
"Keith C. Clarke"
] | [] | [] | [] |
InfoVis | 2,007 | Legible Cities: Focus-Dependent Multi-Resolution Visualization of Urban Relationships | 10.1109/TVCG.2007.70574 | Numerous systems have been developed to display large collections of data for urban contexts; however, most have focused on layering of single dimensions of data and manual calculations to understand relationships within the urban environment. Furthermore, these systems often limit the user's perspectives on the data, thereby diminishing the user's spatial understanding of the viewing region. In this paper, we introduce a highly interactive urban visualization tool that provides intuitive understanding of the urban data. Our system utilizes an aggregation method that combines buildings and city blocks into legible clusters, thus providing continuous levels of abstraction while preserving the user's mental model of the city. In conjunction with a 3D view of the urban model, a separate but integrated information visualization view displays multiple disparate dimensions of the urban data, allowing the user to understand the urban environment both spatially and cognitively in one glance. For our evaluation, expert users from various backgrounds viewed a real city model with census data and confirmed that our system allowed them to gain more intuitive and deeper understanding of the urban model from different perspectives and levels of abstraction than existing commercial urban visualization systems. | false | false | [
"Remco Chang",
"Ginette Wessel",
"Robert Kosara",
"Eric Sauda",
"William Ribarsky"
] | [] | [] | [] |
InfoVis | 2,007 | ManyEyes: a Site for Visualization at Internet Scale | 10.1109/TVCG.2007.70577 | We describe the design and deployment of Many Eyes, a public Web site where users may upload data, create interactive visualizations, and carry on discussions. The goal of the site is to support collaboration around visualizations at a large scale by fostering a social style of data analysis in which visualizations not only serve as a discovery tool for individuals but also as a medium to spur discussion among users. To support this goal, the site includes novel mechanisms for end-user creation of visualizations and asynchronous collaboration around those visualizations. In addition to describing these technologies, we provide a preliminary report on the activity of our users. | false | false | [
"Fernanda B. Viégas",
"Martin Wattenberg",
"Frank van Ham",
"Jesse Kriss",
"Matthew M. McKeon"
] | [
"TT"
] | [] | [] |
InfoVis | 2,007 | Multi-Level Graph Layout on the GPU | 10.1109/TVCG.2007.70580 | This paper presents a new algorithm for force directed graph layout on the GPU. The algorithm, whose goal is to compute layouts accurately and quickly, has two contributions. The first contribution is proposing a general multi-level scheme, which is based on spectral partitioning. The second contribution is computing the layout on the GPU. Since the GPU requires a data parallel programming model, the challenge is devising a mapping of a naturally unstructured graph into a well-partitioned structured one. This is done by computing a balanced partitioning of a general graph. This algorithm provides a general multi-level scheme, which has the potential to be used not only for computation on the GPU, but also on emerging multi-core architectures. The algorithm manages to compute high quality layouts of large graphs in a fraction of the time required by existing algorithms of similar quality. An application for visualization of the topologies of ISP (Internet service provider) networks is presented. | false | false | [
"Yaniv Frishman",
"Ayellet Tal"
] | [] | [] | [] |
InfoVis | 2,007 | NodeTrix: a Hybrid Visualization of Social Networks | 10.1109/TVCG.2007.70582 | The need to visualize large social networks is growing as hardware capabilities make analyzing large networks feasible and many new data sets become available. Unfortunately, the visualizations in existing systems do not satisfactorily resolve the basic dilemma of being readable both for the global structure of the network and also for detailed analysis of local communities. To address this problem, we present NodeTrix, a hybrid representation for networks that combines the advantages of two traditional representations: node-link diagrams are used to show the global structure of a network, while arbitrary portions of the network can be shown as adjacency matrices to better support the analysis of communities. A key contribution is a set of interaction techniques. These allow analysts to create a NodeTrix visualization by dragging selections to and from node-link and matrix forms, and to flexibly manipulate the NodeTrix representation to explore the dataset and create meaningful summary visualizations of their findings. Finally, we present a case study applying NodeTrix to the analysis of the InfoVis 2004 coauthorship dataset to illustrate the capabilities of NodeTrix as both an exploration tool and an effective means of communicating results. | false | false | [
"Nathalie Henry Riche",
"Jean-Daniel Fekete",
"Michael J. McGuffin"
] | [] | [] | [] |
InfoVis | 2,007 | Overview Use in Multiple Visual Information Resolution Interfaces | 10.1109/TVCG.2007.70583 | In interfaces that provide multiple visual information resolutions (VIR), low-VIR overviews typically sacrifice visual details for display capacity, with the assumption that users can select regions of interest to examine at higher VI Rs. Designers can create low VIRs based on multi-level structure inherent in the data, but have little guidance with single-level data. To better guide design tradeoff between display capacity and visual target perceivability, we looked at overview use in two multiple-VIR interfaces with high-VIR displays either embedded within, or separate from, the overviews. We studied two visual requirements for effective overview and found that participants would reliably use the low-VIR overviews only when the visual targets were simple and had small visual spans. Otherwise, at least 20% chose to use the high-VIR view exclusively. Surprisingly, neither of the multiple-VIR interfaces provided performance benefits when compared to using the high-VIR view alone. However, we did observe benefits in providing side-by-side comparisons for target matching. We conjecture that the high cognitive load of multiple-VIR interface interactions, whether real or perceived, is a more considerable barrier to their effective use than was previously considered. | false | false | [
"Heidi Lam",
"Tamara Munzner",
"Robert Kincaid"
] | [] | [] | [] |
InfoVis | 2,007 | Scented Widgets: Improving Navigation Cues with Embedded Visualizations | 10.1109/TVCG.2007.70589 | This paper presents scented widgets, graphical user interface controls enhanced with embedded visualizations that facilitate navigation in information spaces. We describe design guidelines for adding visual cues to common user interface widgets such as radio buttons, sliders, and combo boxes and contribute a general software framework for applying scented widgets within applications with minimal modifications to existing source code. We provide a number of example applications and describe a controlled experiment which finds that users exploring unfamiliar data make up to twice as many unique discoveries using widgets imbued with social navigation data. However, these differences equalize as familiarity with the data increases. | false | false | [
"Wesley Willett",
"Jeffrey Heer",
"Maneesh Agrawala"
] | [] | [] | [] |
InfoVis | 2,007 | Sequential Document Visualization | 10.1109/TVCG.2007.70592 | Documents and other categorical valued time series are often characterized by the frequencies of short range sequential patterns such as n-grams. This representation converts sequential data of varying lengths to high dimensional histogram vectors which are easily modeled by standard statistical models. Unfortunately, the histogram representation ignores most of the medium and long range sequential dependencies making it unsuitable for visualizing sequential data. We present a novel framework for sequential visualization of discrete categorical time series based on the idea of local statistical modeling. The framework embeds categorical time series as smooth curves in the multinomial simplex summarizing the progression of sequential trends. We discuss several visualization techniques based on the above framework and demonstrate their usefulness for document visualization. | false | false | [
"Yi Mao",
"Joshua V. Dillon",
"Guy Lebanon"
] | [] | [] | [] |
InfoVis | 2,007 | Show Me: Automatic Presentation for Visual Analysis | 10.1109/TVCG.2007.70594 | This paper describes Show Me, an integrated set of user interface commands and defaults that incorporate automatic presentation into a commercial visual analysis system called Tableau. A key aspect of Tableau is VizQL, a language for specifying views, which is used by Show Me to extend automatic presentation to the generation of tables of views (commonly called small multiple displays). A key research issue for the commercial application of automatic presentation is the user experience, which must support the flow of visual analysis. User experience has not been the focus of previous research on automatic presentation. The Show Me user experience includes the automatic selection of mark types, a command to add a single field to a view, and a pair of commands to build views for multiple fields. Although the use of these defaults and commands is optional, user interface logs indicate that Show Me is used by commercial users. | false | false | [
"Jock D. Mackinlay",
"Pat Hanrahan",
"Chris Stolte"
] | [] | [] | [] |
InfoVis | 2,007 | Spatialization Design: Comparing Points and Landscapes | 10.1109/TVCG.2007.70596 | Spatializations represent non-spatial data using a spatial layout similar to a map. We present an experiment comparing different visual representations of spatialized data, to determine which representations are best for a non-trivial search and point estimation task. Primarily, we compare point-based displays to 2D and 3D information landscapes. We also compare a colour (hue) scale to a grey (lightness) scale. For the task we studied, point-based spatializations were far superior to landscapes, and 2D landscapes were superior to 3D landscapes. Little or no benefit was found for redundantly encoding data using colour or greyscale combined with landscape height. 3D landscapes with no colour scale (height-only) were particularly slow and inaccurate. A colour scale was found to be better than a greyscale for all display types, but a greyscale was helpful compared to height-only. These results suggest that point-based spatializations should be chosen over landscape representations, at least for tasks involving only point data itself rather than derived information about the data space. | false | false | [
"Melanie Tory",
"David W. Sprague",
"Fuqu Wu",
"Wing Yan So",
"Tamara Munzner"
] | [] | [] | [] |
InfoVis | 2,007 | Toward a Deeper Understanding of the Role of Interaction in Information Visualization | 10.1109/TVCG.2007.70515 | Even though interaction is an important part of information visualization (Infovis), it has garnered a relatively low level of attention from the Infovis community. A few frameworks and taxonomies of Infovis interaction techniques exist, but they typically focus on low-level operations and do not address the variety of benefits interaction provides. After conducting an extensive review of Infovis systems and their interactive capabilities, we propose seven general categories of interaction techniques widely used in Infovis: 1) Select, 2) Explore, 3) Reconfigure, 4) Encode, 5) Abstract/Elaborate, 6) Filter, and 7) Connect. These categories are organized around a user's intent while interacting with a system rather than the low-level interaction techniques provided by a system. The categories can act as a framework to help discuss and evaluate interaction techniques and hopefully lay an initial foundation toward a deeper understanding and a science of interaction. | false | false | [
"Ji Soo Yi",
"Youn ah Kang",
"John T. Stasko",
"Julie A. Jacko"
] | [] | [] | [] |
InfoVis | 2,007 | VisLink: Revealing Relationships Amongst Visualizations | 10.1109/TVCG.2007.70521 | We present VisLink, a method by which visualizations and the relationships between them can be interactively explored. VisLink readily generalizes to support multiple visualizations, empowers inter-representational queries, and enables the reuse of the spatial variables, thus supporting efficient information encoding and providing for powerful visualization bridging. Our approach uses multiple 2D layouts, drawing each one in its own plane. These planes can then be placed and re-positioned in 3D space: side by side, in parallel, or in chosen placements that provide favoured views. Relationships, connections, and patterns between visualizations can be revealed and explored using a variety of interaction techniques including spreading activation and search filters. | false | false | [
"Christopher Collins 0001",
"Sheelagh Carpendale"
] | [] | [] | [] |
InfoVis | 2,007 | Visual Analysis of Network Traffic for Resource Planning, Interactive Monitoring, and Interpretation of Security Threats | 10.1109/TVCG.2007.70522 | The Internet has become a wild place: malicious code is spread on personal computers across the world, deploying botnets ready to attack the network infrastructure. The vast number of security incidents and other anomalies overwhelms attempts at manual analysis, especially when monitoring service provider backbone links. We present an approach to interactive visualization with a case study indicating that interactive visualization can be applied to gain more insight into these large data sets. We superimpose a hierarchy on IP address space, and study the suitability of Treemap variants for each hierarchy level. Because viewing the whole IP hierarchy at once is not practical for most tasks, we evaluate layout stability when eliding large parts of the hierarchy, while maintaining the visibility and ordering of the data of interest. | false | false | [
"Florian Mansmann",
"Daniel A. Keim",
"Stephen C. North",
"Brian Rexroad",
"Daniel Sheleheda"
] | [] | [] | [] |
InfoVis | 2,007 | Visualization of Heterogeneous Data | 10.1109/TVCG.2007.70617 | Both the resource description framework (RDF), used in the semantic web, and Maya Viz u-forms represent data as a graph of objects connected by labeled edges. Existing systems for flexible visualization of this kind of data require manual specification of the possible visualization roles for each data attribute. When the schema is large and unfamiliar, this requirement inhibits exploratory visualization by requiring a costly up-front data integration step. To eliminate this step, we propose an automatic technique for mapping data attributes to visualization attributes. We formulate this as a schema matching problem, finding appropriate paths in the data model for each required visualization attribute in a visualization template. | false | false | [
"Mike Cammarano",
"Xin Dong 0001",
"Bryan Chan 0001",
"Jeff Klingner",
"Justin Talbot",
"Alon Y. Halevy",
"Pat Hanrahan"
] | [] | [] | [] |
InfoVis | 2,007 | Visualizing Causal Semantics Using Animations | 10.1109/TVCG.2007.70528 | Michotte's theory of ampliation suggests that causal relationships are perceived by objects animated under appropriate spatiotemporal conditions. We extend the theory of ampliation and propose that the immediate perception of complex causal relations is also dependent on a set of structural and temporal rules. We designed animated representations, based on Michotte's rules, for showing complex causal relationships or causal semantics. In this paper we describe a set of animations for showing semantics such as causal amplification, causal strength, causal dampening, and causal multiplicity. In a two part study we compared the effectiveness of both the static and animated representations. The first study (N=44) asked participants to recall passages that were previously displayed using both types of representations. Participants were 8% more accurate in recalling causal semantics when they were presented using animations instead of static graphs. In the second study (N=112) we evaluated the intuitiveness of the representations. Our results showed that while users were as accurate with the static graphs as with the animations, they were 9% faster in matching the correct causal statements in the animated condition. Overall our results show that animated diagrams that are designed based on perceptual rules such as those proposed by Michotte have the potential to facilitate comprehension of complex causal relations. | false | false | [
"Nivedita R. Kadaba",
"Pourang Irani",
"Jason Leboe-McGowan"
] | [] | [] | [] |
InfoVis | 2,007 | Visualizing Changes of Hierarchical Data using Treemaps | 10.1109/TVCG.2007.70529 | 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. | false | false | [
"Ying Tu",
"Han-Wei Shen"
] | [] | [] | [] |
InfoVis | 2,007 | Visualizing the History of Living Spaces | 10.1109/TVCG.2007.70621 | The technology available to building designers now makes it possible to monitor buildings on a very large scale. Video cameras and motion sensors are commonplace in practically every office space, and are slowly making their way into living spaces. The application of such technologies, in particular video cameras, while improving security, also violates privacy. On the other hand, motion sensors, while being privacy-conscious, typically do not provide enough information for a human operator to maintain the same degree of awareness about the space that can be achieved by using video cameras. We propose a novel approach in which we use a large number of simple motion sensors and a small set of video cameras to monitor a large office space. In our system we deployed 215 motion sensors and six video cameras to monitor the 3,000-square-meter office space occupied by 80 people for a period of about one year. The main problem in operating such systems is finding a way to present this highly multidimensional data, which includes both spatial and temporal components, to a human operator to allow browsing and searching recorded data in an efficient and intuitive way. In this paper we present our experiences and the solutions that we have developed in the course of our work on the system. We consider this work to be the first step in helping designers and managers of building systems gain access to information about occupants' behavior in the context of an entire building in a way that is only minimally intrusive to the occupants' privacy. | false | false | [
"Yuri A. Ivanov",
"Christopher Richard Wren",
"Alexander Sorokin",
"Ishwinder Kaur"
] | [
"BP"
] | [] | [] |
InfoVis | 2,007 | Weaving Versus Blending: a quantitative assessment of the information carrying capacities of two alternative methods for conveying multivariate data with color. | 10.1109/TVCG.2007.70623 | In many applications, it is important to understand the individual values of, and relationships between, multiple related scalar variables defined across a common domain. Several approaches have been proposed for representing data in these situations. In this paper we focus on strategies for the visualization of multivariate data that rely on color mixing. In particular, through a series of controlled observer experiments, we seek to establish a fundamental understanding of the information-carrying capacities of two alternative methods for encoding multivariate information using color: color blending and color weaving. We begin with a baseline experiment in which we assess participants' abilities to accurately read numerical data encoded in six different basic color scales defined in the L*a*b* color space. We then assess participants' abilities to read combinations of 2, 3, 4 and 6 different data values represented in a common region of the domain, encoded using either color blending or color weaving. In color blending a single mixed color is formed via linear combination of the individual values in L*a*b* space, and in color weaving the original individual colors are displayed side-by-side in a high frequency texture that fills the region. A third experiment was conducted to clarify some of the trends regarding the color contrast and its effect on the magnitude of the error that was observed in the second experiment. The results indicate that when the component colors are represented side-by-side in a high frequency texture, most participants' abilities to infer the values of individual components are significantly improved, relative to when the colors are blended. Participants' performance was significantly better with color weaving particularly when more than 2 colors were used, and even when the individual colors subtended only 3 minutes of visual angle in the texture. However, the information-carrying capacity of the color weaving approach has its limits. We found that participants' abilities to accurately interpret each of the individual components in a high frequency color texture typically falls off as the number of components increases from 4 to 6. We found no significant advantages, in either color blending or color weaving, to using color scales based on component hues thatare more widely separated in the L*a*b* color space. Furthermore, we found some indications that extra difficulties may arise when opponent hues are employed. | false | false | [
"Haleh Hagh-Shenas",
"Sunghee Kim",
"Victoria Interrante",
"Christopher G. Healey"
] | [] | [] | [] |
EuroVis | 2,007 | A Tri-Space Visualization Interface for Analyzing Time-Varying Multivariate Volume Data | 10.2312/VisSym/EuroVis07/115-122 | The dataset generated by a large-scale numerical simulation may include thousands of timesteps and hundreds of variables describing different aspects of the modeled physical phenomena. In order to analyze and understand such data, scientists need the capability to explore simultaneously in the temporal, spatial, and variable domains of the data. Such capability, however, is not generally provided by conventional visualization tools. This paper presents a new visualization interface addressing this problem. The interface consists of three components which abstracts the complexity of exploring in temporal, variable, and spatial domain, respectively. The first component displays time histograms of the data, helps the user identify timesteps of interest, and also helps specify time-varying features. The second component displays correlations between variables in parallel coordinates and enables the user to verify those correlations and possibly identity unanticipated ones. The third component allows the user to more closely explore and validate the data in spatial domain while rendering multiple variables into a single visualization in a user controllable fashion. Each of these three components is not only an interface but is also the visualization itself, thus enabling efficient screen-space usage. The three components are tightly linked to facilitate tri-space data exploration, which offers scientists new power to study their time-varying, multivariate volume data. | false | false | [
"Hiroshi Akiba",
"Kwan-Liu Ma"
] | [] | [] | [] |
EuroVis | 2,007 | Animation of Orthogonal Texture-Based Vector Field Visualization | 10.2312/VisSym/EuroVis07/219-226 | This paper introduces orthogonal vector field visualization on 2D manifolds: a representation by lines that are perpendicular to the input vector field. Line patterns are generated by line integral convolution (LIC). This visualization is combined with animation based on motion along the vector field. This decoupling of the line direction from the direction of animation allows us to choose the spatial frequencies along the direction of motion independently from the length scales along the LIC line patterns. Vision research indicates that local motion detectors are tuned to certain spatial frequencies of textures, and the above decoupling enables us to generate spatial frequencies optimized for motion perception. In addition, a filtering process is described to achieve a consistent and temporally coherent animation of the orthogonal vector field visualization. We present respective visualization algorithms for 2D planar vector fields and tangential vector fields on curved surfaces, and demonstrate that those algorithms lend themselves to efficient and interactive GPU implementations. | false | false | [
"Sven Bachthaler",
"Daniel Weiskopf"
] | [] | [] | [] |
EuroVis | 2,007 | Depth Cues and Density in Temporal Parallel Coordinates | 10.2312/VisSym/EuroVis07/035-042 | This paper introduces Temporal Density Parallel Coordinates (TDPC) and Depth Cue Parallel Coordinates (DCPC) which extend the standard 2D parallel coordinates technique to capture time-varying dynamics. The proposed techniques can be used to analyse temporal positions of data items as well as temporal positions of changes occurring using 2D displays. To represent temporal changes, polygons (instead of traditional lines) are rendered in parallel coordinates. The results presented show that rendering polygons is superior at revealing large temporal changes. Both TDPC and DCPC have been efficiently implemented on the GPU allowing the visualization of thousands of data items over thousands of time steps at interactive frame rates. | false | false | [
"Jimmy Johansson 0001",
"Patric Ljung",
"Matthew Cooper 0001"
] | [] | [] | [] |
EuroVis | 2,007 | Design of Multi-dimensional Transfer Functions Using Dimensional Reduction | 10.2312/VisSym/EuroVis07/131-138 | Direct volume rendering techniques allow visualization of volume data without extracting intermediate geometry. The mapping from voxel attributes to optical properties is performed by transfer functions which, consequently, play a crucial role in building informative images from the data. One-dimensional transfer functions, which are based only on a scalar value per voxel, often do not provide proper visualizations. On the other hand, multidimensional transfer functions can perform more sophisticated data classification, based on vectorial voxel signatures. The transfer function design is a non-trivial and unintuitive task, especially in the multi-dimensional case. In this paper we propose a multi-dimensional transfer function design technique that uses self-organizing maps to perform dimensional reduction. Our approach gives uniform treatment to volume data containing voxel signatures of arbitrary dimension, and allows the use of any type of voxel attribute as part of the voxel signatures. | false | false | [
"Francisco de Moura Pinto",
"Carla M. D. S. Freitas"
] | [] | [] | [] |
EuroVis | 2,007 | Dimensional Congruence for Interactive Visual Data Mining and Knowledge Discovery | 10.2312/VisSym/EuroVis07/099-106 | Many authors in the field of 3D human computer interaction have described the advantages of 3D user interfaces: Intuitive metaphors from daily life, immersive workspaces, virtual environments that closely resemble natural environments, and the usefulness of the third dimension as an additional visualization scale. Nevertheless, there are still few or no successful applications for complex information spaces that make use of it in a natural human-centered manner. In this paper, we propose a novel hybrid user interface for knowledge workers to support document spaces and corresponding visualizations. We propose a combined 2D + 3D interface to support both visualization approaches and interaction metaphors to their maximum potential. Interaction is matched due to the principle of dimensional congruence and a thorough investigation of previous approaches and problems is given. Finally, a user study to evaluate the effectiveness and usability of the proposed system is presented. | false | false | [
"Sebastian Baumgärtner",
"Achim Ebert",
"Matthias Deller"
] | [] | [] | [] |
EuroVis | 2,007 | Feature Emphasis and Contextual Cutaways for Multimodal Medical Visualization | 10.2312/VisSym/EuroVis07/275-282 | Dense clinical data like 3D Computed Tomography (CT) scans can be visualized together with real-time imaging for a number of medical intervention applications. However, it is difficult to provide a fused visualization that allows sufficient spatial perception of the anatomy of interest, as derived from the rich pre-operative scan, while not occluding the real-time image displayed embedded within the volume.
We propose an importance-driven approach that presents the embedded data such that it is clearly visible along with its spatial relation to the surrounding volumetric material. To support this, we present and integrate novel techniques for importance specification, feature emphasis, and contextual cutaway generation. We show results in a clinical context where a pre-operative CT scan is visualized alongside a tracked ultrasound image, such that the important vasculature is depicted between the viewpoint and the ultrasound image, while a more opaque representation of the anatomy is exposed in the surrounding area. | false | false | [
"Michael Burns",
"Martin Haidacher",
"Wolfgang Wein",
"Ivan Viola",
"M. Eduard Gröller"
] | [] | [] | [] |
EuroVis | 2,007 | Feature Identification and Extraction in Function Fields | 10.2312/VisSym/EuroVis07/195-201 | We present interactive techniques for identifying and extracting features in function fields. Function fields map points in n-dimensional Euclidean space to 1-dimensional scalar functions. Visual feature identification is ac- complished by interactively rendering scalar distance fields, constructed by applying a function-space distance metric over the function field. Combining visual exploration with feature extraction queries, formulated as a set of function-space constraints, facilitates quantitative analysis and annotation. Numerous application domains give rise to function fields. We present results for two-dimensional hyperspectral images, and a simulated time-varying, three-dimensional air quality dataset. | false | false | [
"John C. Anderson",
"Luke J. Gosink",
"Mark A. Duchaineau",
"Kenneth I. Joy"
] | [] | [] | [] |
EuroVis | 2,007 | Flexible And Topologically Localized Segmentation | 10.2312/VisSym/EuroVis07/179-186 | One of the most common visualization tasks is the extraction of significant boundaries, often performed with isosurfaces or level set segmentation. Isosurface extraction is simple and can be guided by geometric and topological analysis, yet frequently does not extract the desired boundary. Level set segmentation is better at boundary extraction, but either leads to global segmentation without edges, [CV01], that scales unfavorably in 3D or requires an initial estimate of the boundary from which to locally solve segmentation with edges. We propose a hybrid system in which topological analysis is used for semi-automatic initialization of a level set segmentation, and geometric information bounded topologically is used to guide and accelerate an iterative segmentation algorithm that combines several state-of-the-art level set terms. We thus combine and improve both the flexible isosurface interface and level set segmentation without edges. | false | false | [
"Gunnar Johansson",
"Ken Museth",
"Hamish A. Carr"
] | [] | [] | [] |
EuroVis | 2,007 | Functional Unit Maps for Data-Driven Visualization of High-Density EEG Coherence | 10.2312/VisSym/EuroVis07/259-266 | Synchronous electrical activity in different brain regions is generally assumed to imply functional relationships between these regions. A measure for this synchrony is electroencephalography (EEG) coherence, computed between pairs of signals as a function of frequency. Existing high-density EEG coherence visualizations are generally either hypothesis-driven, or data-driven graph visualizations which are cluttered. In this paper, a new method is presented for data-driven visualization of high-density EEG coherence, which strongly reduces clutter and is referred to as functional unit (FU) map. Starting from an initial graph, with vertices representing electrodes and edges representing significant coherences between electrode signals, we define an FU as a set of electrodes represented by a clique consisting of spatially connected vertices. In an FU map, the spatial relationship between electrodes is preserved, and all electrodes in one FU are assigned an identical gray value. Adjacent FUs are visualized with different gray values and FUs are connected by a line if the average coherence between FUs exceeds a threshold. Results obtained with our visualization are in accordance with known electrophysiological findings. FU maps can be used as a preprocessing step for conventional analysis. | false | false | [
"Michael ten Caat",
"Natasha M. Maurits",
"Jos B. T. M. Roerdink"
] | [] | [] | [] |
EuroVis | 2,007 | Grouse: Feature-Based, Steerable Graph Hierarchy Exploration | 10.2312/VisSym/EuroVis07/067-074 | Grouse is a feature-based approach to steerable exploration of a graph and an associated hierarchy. Steerability allows exploration to begin immediately, rather than requiring a costly layout of the entire graph as an initial step. In a feature-based approach, the subgraph inside a metanode of the graph hierarchy is laid out with a well- chosen algorithm appropriate for its topological structure. Grouse preserves the input hierarchy, which provides meaningful information to the user when its metanodes correspond to features of interest. When a metanode in the hierarchy is opened, a limited number of metanodes are laid out again along the path between the opened node and the root. We demonstrate the effectiveness of Grouse on datasets from IMDB, the Internet Movie Database, where nodes are actors and cliques represent movies. The combination of feature-based layout and limited relayout computation does not fragment features in the hierarchy and improves the number of levels in the hierarchy that can be seen at once over previous approaches. | false | false | [
"Daniel Archambault",
"Tamara Munzner",
"David Auber"
] | [] | [] | [] |
EuroVis | 2,007 | Hardware-accelerated Stippling of Surfaces derived from Medical Volume Data | 10.2312/VisSym/EuroVis07/235-242 | We present a fast hardware-accelerated stippling method which does not require any preprocessing for placing points on surfaces. The surfaces are automatically parameterized in order to apply stippling textures without major distortions. The mapping process is guided by a decomposition of the space in cubes. Seamless scaling with a constant density of points is realized by subdividing and summarizing cubes. Our mip-map technique enables arbitrarily scaling with one texture. Different shading tones and scales are facilitated by adhering to the constraints of tonal art maps. With our stippling technique, it is feasible to encode all scaling and brightness levels within one self-similar texture. Our method is applied to surfaces extracted from (segmented) medical volume data. The speed of the stippling process enables stippling for several complex objects simultaneously. We consider application scenarios in intervention planning (neck and liver surgery planning). In these scenarios, object recognition (shape perception) is supported by adding stippling to semi-transparently shaded objects which are displayed as context information. | false | false | [
"Alexandra Baer",
"Christian Tietjen",
"Ragnar Bade",
"Bernhard Preim"
] | [] | [] | [] |
EuroVis | 2,007 | Integrating Local Feature Detectors in the Interactive Visual Analysis of Flow Simulation Data | 10.2312/VisSym/EuroVis07/171-178 | We present smooth formulations of common vortex detectors that allow a seamless integration into the concept of interactive visual analysis of flow simulation data. We express the originally binary feature detectors as fuzzy-sets that can be combined using the linking and brushing concepts of interactive visual analysis. Both interaction and visualization gain from having multiple detectors concurrently available and from the ability to combine them. An application study on automotive data reveals how these vortex detectors combine and perform in praxis. | false | false | [
"Raphael Buerger",
"Philipp Muigg",
"Martin Ilcík",
"Helmut Doleisch",
"Helwig Hauser"
] | [] | [] | [] |
EuroVis | 2,007 | Interactive Visual Exploration of Unsteady 3D Flows | 10.2312/VisSym/EuroVis07/251-258 | In this paper we present GPU-based techniques for the interactive visualization of large unsteady 3D flow fields on uniform grids. We propose a novel dual-core approach to asynchronously stream such fields from the CPU, thus enabling the efficient exploration of large time-resolved sequences. This approach decouples visualization from data handling, resulting in interactive frame rates. Built upon a previously published GPU particle engine for flow visualization we have developed new strategies to compute and to visualize path lines and streak lines on the GPU. To provide additional visual cues, focus+context techniques for polygonal meshes have been integrated. The proposed techniques are used in the visual analysis of the Terashake 2.1 earthquake simulation data, and they have been shown to be very effective in revealing the relevant information in this data. | false | false | [
"Kai Bürger",
"Jens Schneider 0002",
"Polina Kondratieva",
"Jens H. Krüger",
"Rüdiger Westermann"
] | [] | [] | [] |
EuroVis | 2,007 | Interactive Visualization of Multi-Field Medical Data Using Linked Physical and Feature-Space Views | 10.2312/VisSym/EuroVis07/123-130 | Multi-field datasets contain multiple parameters defined over the same spatio-temporal domain. In medicine, such multi-field data is being used more often every day, and there is an urgent need for exploratory visualization approaches that are able to deal effectively with the data-analysis. In this paper, we present a highly interactive, coordinated view-based visualization approach that has been developed especially for dealing with multi-field medical data. It can show any number of views of the physical domain and also of the abstract high-dimensional feature space. The approach has been optimized for interactive use with very large datasets. It is based on intuitive interaction techniques, and integrates analysis techniques from pattern classification to guide the exploration process. We will give some details about the implementation, and we demonstrate the utility of our approach with two real medical use cases. | false | false | [
"Jorik Blaas",
"Charl P. Botha",
"Frits H. Post"
] | [] | [] | [] |
EuroVis | 2,007 | KeyStrokes: Personalizing Typed Text with Visualization | 10.2312/VisSym/EuroVis07/043-050 | With the ubiquity of typed text, the style and much of the personality of handwriting has been lost from general communication. To counter this we introduce an artistic real-time visualization of typed messages that additionally captures and encodes aspects of an individual's unique typing style. The potential of our system to augment electronic communication was evaluated and the results are provided along with analysis of their implications for social visualization. | false | false | [
"Petra Neumann 0001",
"Annie Tat",
"Torre Zuk",
"Sheelagh Carpendale"
] | [] | [] | [] |
EuroVis | 2,007 | Manual Clustering Refinement using Interaction with Blobs | 10.2312/VisSym/EuroVis07/059-066 | The huge amount of different automatic clustering methods emphasizes one thing: there is no optimal clustering method for all possible cases. In certain application domains, like genomics and natural language processing, it is not even clear if any of the already known clustering methods suffice. In such cases, an automatic clustering method is often followed by manual refinement. The refined version may then be used as either an illustration, a reference, or even an input for a rule based or other machine learning algorithm as a new clustering method. In this paper, we describe a novel interaction technique to manual cluster refinement using the metaphor of soap bubbles, represented by special implicit surfaces (blobs). For instance, entities can simply be moved inside and outside of these blobs. A modified force-directed layout process automatically arranges entities equidistant on the screen. The modifications include a reduction to the expected amount of computation per iteration down to O(|V| log |V|+|E|) in order to achieve a high response time for use in an interactive system. We also spend a considerable amount of effort making the display of blobs fast enough for an interactive system. | false | false | [
"Christian Heine 0002",
"Gerik Scheuermann"
] | [] | [] | [] |
EuroVis | 2,007 | Model-free Surface Visualization of Vascular Trees | 10.2312/VisSym/EuroVis07/283-290 | Expressive and efficient visualizations of complex vascular structures are essential for medical applications, such as diagnosis and therapy planning. A variety of techniques has been developed which provide smooth high-quality visualizations of vascular structures based on rather simple model assumptions. For diagnostic applications, these model assumptions and the resulting deviations from the actual vessel surface are not acceptable. We present a model-free approach which employs the binary result of a prior vessel segmentation as input. Instead of directly converting the segmentation result into a surface, we compute a point cloud which is adaptively refined at thin structures, where aliasing effects are particularly obvious and artifacts may occur. The point cloud is transformed into a surface representation by means of MPU Implicits, which provide a smooth piecewise quadratic approximation. Our method has been applied to a variety of datasets including pathologic cases. The generated visualizations are considerably more accurate than model-based approaches. Compared to other model-free approaches, our method produces smoother results. | false | false | [
"Christian Schumann",
"Steffen Oeltze",
"Ragnar Bade",
"Bernhard Preim",
"Heinz-Otto Peitgen"
] | [] | [] | [] |
EuroVis | 2,007 | Multi-Resolution Techniques for Visual Exploration of Large Time-Series Data | 10.2312/VisSym/EuroVis07/027-034 | Time series are a data type of utmost importance in many domains such as business management and service monitoring. We address the problem of visualizing large time-related data sets which are difficult to visualize effectively with standard techniques given the limitations of current display devices. We propose a framework for intelligent time- and data-dependent visual aggregation of data along multiple resolution levels. This idea leads to effective visualization support for long time-series data providing both focus and context. The basic idea of the technique is that either data-dependent or application-dependent, display space is allocated in proportion to the degree of interest of data subintervals, thereby (a) guiding the user in perceiving important information, and (b) freeing required display space to visualize all the data. The automatic part of the framework can accommodate any time series analysis algorithm yielding a numeric degree of interest scale. We apply our techniques on real-world data sets, compare it with the standard visualization approach, and conclude the usefulness and scalability of the approach. | false | false | [
"Ming C. Hao",
"Umeshwar Dayal",
"Daniel A. Keim",
"Tobias Schreck"
] | [] | [] | [] |
EuroVis | 2,007 | Multiresolution MIP Rendering of Large Volumetric Data Accelerated on Graphics Hardware | 10.2312/VisSym/EuroVis07/243-250 | This paper is concerned with a multiresolution representation for maximum intensity projection (MIP) volume rendering based on morphological pyramids which allows progressive refinement. We consider two algorithms for progressive rendering from the morphological pyramid: one which projects detail coefficients level by level, and a second one, called streaming MIP, which resorts the detail coefficients of all levels simultaneously with respect to decreasing magnitude of a suitable error measure. The latter method outperforms the level-by-level method, both with respect to image quality with a fixed amount of detail data, and in terms of flexibility of controlling approximation error or computation time. We improve the streaming MIP algorithm, present a GPU implementation for both methods, and perform a comparison with existing CPU and GPU implementations. | false | false | [
"Wladimir J. van der Laan",
"Andrei C. Jalba",
"Jos B. T. M. Roerdink"
] | [] | [] | [] |
EuroVis | 2,007 | Multiscale Visualization of Dynamic Software Logs | 10.2312/VisSym/EuroVis07/011-018 | We present a set of techniques and design principles for the visualization of large dynamic software logs consisting of attributed change events, such as obtained from instrumenting programs or mining software repositories. We enhance the visualization scalability with importance-based antialiasing techniques that guarantee visibility of several types of events. We present a hierarchical clustering method that uncovers several patterns of interest in the event logs, such as same-lifetime memory allocations and software releases. We visualize the clusters using a new type of technique called interleaved cushions. We demonstrate our methods on two real-world problems: the monitoring of a dynamic memory allocator and the analysis of a software repository. | false | false | [
"Sergio Moreta",
"Alexandru C. Telea"
] | [] | [] | [] |
EuroVis | 2,007 | Online Dynamic Graph Drawing | 10.2312/VisSym/EuroVis07/075-082 | This paper presents an algorithm for drawing a sequence of graphs online. The algorithm strives to maintain the global structure of the graph and thus the user's mental map, while allowing arbitrary modifications between consecutive layouts. The algorithm works online and uses various execution culling methods in order to reduce the layout time and handle large dynamic graphs. Techniques for representing graphs on the GPU allow a speedup by a factor of up to 8 compared to the CPU implementation. An application to visualization of discussion threads in Internet sites is provided. | false | false | [
"Yaniv Frishman",
"Ayellet Tal"
] | [
"BP"
] | [] | [] |
EuroVis | 2,007 | Parametric Visualization of High Resolution Correlated Multi-spectral Features Using PCA | 10.2312/VisSym/EuroVis07/203-210 | An imaging mass spectrometer is an analytical instrument that can determine the spatial distribution of chemical compounds on complex surfaces. The output of the device is a multi-spectral datacube; a three-dimensional (3D) dataset in which the xy-dimension represents the surface position and the z-dimension represents the mass spectral distribution. Analysts try to discover correlations in spectral profiles and spatial distributions inside a datacube. New technological developments allow mass spectrometric imaging on a higher spatial and spectral resolution. In this paper we present a parametric visualization technique which allows an analyst to examine spectral and spatially correlated patterns on the highest possible resolution. Principal component analysis (PCA) is used to decompose the datacube into several discriminating components. We represent these extracted features as abstract geometric shapes and use three parameters to allow for data exploration. The first parameter thresholds the spectral contribution at which an extracted component is visualized. The level of detail the shapes is controlled by a second parameter and a third parameter determines at which density-level the extracted feature is represented. This new visualization technique enables an analyst to select the most relevant spectral correlations and investigate their specific spatial distribution. With this method, less noise is included in the visualization of extracted features and by introducing various levels of detail the full spectral resolution can be utilized. | false | false | [
"Alexander Broersen",
"Robert van Liere",
"Ron M. A. Heeren"
] | [] | [] | [] |
EuroVis | 2,007 | Path Visualization for Adjacency Matrices | 10.2312/VisSym/EuroVis07/083-090 | For displaying a dense graph, an adjacency matrix is superior than a node-link diagram because it is more compact and free of visual clutter. A node-link diagram, however, is far better for the task of path finding because a path can be easily traced by following the corresponding links, provided that the links are not heavily crossed or tangled. We augment adjacency matrices with path visualization and associated interaction techniques to facilitate path finding. Our design is visually pleasing, and also effectively displays multiple paths based on the design commonly found in metro maps. We illustrate and assess the key aspects of our design with the results obtained from two case studies and an informal user study. | false | false | [
"Zeqian Shen",
"Kwan-Liu Ma"
] | [] | [] | [] |
EuroVis | 2,007 | Priority Streamlines: A context-based Visualization of Flow Fields | 10.2312/VisSym/EuroVis07/227-234 | Flow vector fields contain a wealth of information that needs to be visualized. As an extension of the well-known streamline technique, we have developed a context-based method for visualizing steady flow vector fields in two and three dimensions. We call our method "Priority Streamlines". In our approach, the density of the streamlines is controlled by a scalar function that can be user-defined, or be given by additional information (e.g., temperature, pressure, vorticity, velocity) considering the underlying flow vector field. In regions, which are interesting the streamlines are drawn with increased density, while less interesting regions are drawn sparsely. Since streamlines in the most important regions are drawn first, we can use thresholding to obtain a streamline representation highlighting essential features. Color-mapping and transparency can be used for visualizing other information hidden in the flow vector field. | false | false | [
"Michael Schlemmer",
"Ingrid Hotz",
"Bernd Hamann",
"Florian Morr",
"Hans Hagen"
] | [] | [] | [] |
EuroVis | 2,007 | Relevance Driven Visualization of Financial Performance Measures | 10.2312/VisSym/EuroVis07/019-026 | Visual data analysis has received a lot of research interest in recent years, and a wide variety of new visualization techniques and applications have been developed to improve insight into the various application domains. In financial data analysis, however, analysts still primarily rely on a set of statistical performance parameters in combination with traditional line charts in order to evaluate assets and to make decisions, and information visualization is only very slowly entering this important domain. In this paper, we analyze some of the standard statistical measures for technical financial data analysis and demonstrate cases where they produce insufficient and misleading results that do not reflect the real performance of an asset. We propose a technique for visualizing financial time series data that eliminates these inadequacies, offering a complete view on the real performance of an asset. The technique is enhanced by relevance and weighting functions according to the users' preferences in order to emphasize specific regions of interest. Based on these principles we redefine some of the standard performance measures. We apply our technique on real world financial data sets and combine it with higher-level financial analysis techniques such as performance/risk analysis, dominance evaluation, and efficiency curves in order to show how traditional techniques from economics can be improved by modern visual data analysis techniques. | false | false | [
"Hartmut Ziegler",
"Tilo Nietzschmann",
"Daniel A. Keim"
] | [] | [] | [] |
EuroVis | 2,007 | See What You Know: Analyzing Data Distribution to Improve Density Map Visualization | 10.2312/VisSym/EuroVis07/163-170 | Density maps allow for visually rendering density differences, usually mapping density values to a grey or color scale. The paper analyzes the drawbacks arising from the commonly used strategies and introduces a novel technique able to improve the overall mapping process. The technique is driven by statistical knowledge about the density distribution and a set of quality metrics allows for validating, in an objective way, its effectiveness. | false | false | [
"Enrico Bertini",
"Alessio Di Girolamo",
"Giuseppe Santucci"
] | [] | [] | [] |
EuroVis | 2,007 | Segmentation of DT-MRI Anisotropy Isosurfaces | 10.2312/VisSym/EuroVis07/187-194 | While isosurfaces of anisotropy measures for data from diffusion tensor magnetic resonance imaging (DT-MRI) are known to depict major anatomical structures, the anisotropy metric reduces the rich tensor data to a simple scalar field. In this work, we suggest that the part of the data which has been ignored by the metric can be used to segment anisotropy isosurfaces into anatomically meaningful regions. For the implementation, we propose an edge-based watershed method that adapts and extends a method from curvature-based mesh segmentation [MW99]. Finally, we use the segmentation results to enhance visualization of the data. | false | false | [
"Thomas Schultz 0001",
"Holger Theisel",
"Hans-Peter Seidel"
] | [] | [] | [] |
EuroVis | 2,007 | Sonar Explorer: A New Tool for Visualization of Fish Schools from 3D Sonar Data | 10.2312/VisSym/EuroVis07/155-162 | We present a novel framework for analysis and visualization of fish schools in 3D sonar surveys. The 3D sonar technology is new and there have not been applications to visualize the data in 3D. We have created an application called Sonar Explorer that satisfies the requirements of domain scientists. Sonar Explorer provides easy and intuitive semi-automatic fish school tracking and survey map generation. The overall pipeline is described and all pipeline stages relevant for visualization are highlighted. We present techniques to deal with 3D sonar data specifics: highly anisotropic volume data aligned on a curvilinear grid. Domain scientists provide initial impressions on interaction and outlook. | false | false | [
"Jean-Paul Balabanian",
"Ivan Viola",
"Egil Ona",
"Ruben Patel",
"M. Eduard Gröller"
] | [] | [] | [] |
EuroVis | 2,007 | Story Telling for Presentation in Volume Visualization | 10.2312/VisSym/EuroVis07/091-098 | In this paper we present a novel approach to volume visualization for presentation purposes that improves both the comprehensibility and credibility of the intended visualization message. Therefore, we combine selected aspects from storytelling as well as from interactive volume visualization to create a guided but at the same time interactive visualization presentation approach. To ease the observer's access to a presented visualization result we not only communicate the result itself, but also deliver its creational process in the form of an annotated visualization animation, which we call a visualization story. Additionally, we enable variable means of interactivity during story playback. The story observers may just watch the presentation passively, but they are also allowed to reinvestigate the visualization independently from story guidance, offering the ability to verify, confirm, or even disapprove the presented visualization message. For demonstration purposes, we developed a prototype application that provides tools to author, edit, and watch visualization stories. We demonstrate the potential of our approach on the basis of medical visualization examples. | false | false | [
"Michael Wohlfart",
"Helwig Hauser"
] | [] | [] | [] |
EuroVis | 2,007 | Subdivision Volume Splatting | 10.2312/VisSym/EuroVis07/139-146 | Volumetric Subdivision (VS) is a powerful paradigm that enables volumetric sculpting and realistic volume deformations that give rise to the concept of "virtual clay". In VS, volumes are commonly represented as a space-filling set of deformed polyhedra, which can be further decomposed into a mesh of tetrahedra for rendering. Images can then be generated via tetrahedral projection or raycasting. A current shortcoming in VS-based operations is the need for a very high level of subdivision to represent fine detail in the mesh and to obtain a high-fidelity visualization. However, we have discovered that the subdivision process itself can be closely simulated with radial basis functions (RBFs), making it possible to replace the finer subdivision levels by a coarser aggregation of RBF kernels. This reduction to a simplified assembly of RBFs subsequently enables interactive rendering of volumetric subdivision shapes within a GPU-based volume splatting framework. | false | false | [
"Kevin T. McDonnell",
"Neophytos Neophytou",
"Klaus Mueller 0001",
"Hong Qin"
] | [] | [] | [] |
EuroVis | 2,007 | The CoMIRVA Toolkit for Visualizing Music-Related Data | 10.2312/VisSym/EuroVis07/147-154 | We present CoMIRVA, which is an abbreviation for Collection of Music Information Retrieval and Visualization Applications. CoMIRVA is a Java framework and toolkit for information retrieval and visualization. It is licensed under the GNU GPL and can be downloaded from http://www.cp.jku.at/comirva/. At the moment, the main functionalities include music information retrieval, web retrieval, and visualization of the extracted information. In this paper, we focus on the visualization aspects of CoMIRVA. Since many of the information retrieval functions are intended to be applied to problems of the field of music information retrieval (MIR), we demonstrate the functions using data like similarity matrices of music artists gained by analyzing artist-related web pages. CoMIRVA is continuously being extended. Currently, it supports the following visualization techniques: Self-Organizing Map, Smoothed Data Histogram, Circled Bars, Circled Fans, Probabilistic Network, Continuous Similarity Ring, Sunburst, and Music Description Map. Since space is limited, we can only present a selected number of these in this paper. As one key feature of CoMIRVA is its easy extensibility, we further elaborate on how CoMIRVA was used for creating a novel user interface to digital music repositories. | false | false | [
"Markus Schedl",
"Peter Knees",
"Klaus Seyerlehner",
"Tim Pohle"
] | [] | [] | [] |
EuroVis | 2,007 | TrustNeighborhoods: Visualizing Trust in Distributed File Sharing Systems | 10.2312/VisSym/EuroVis07/107-114 | We present TrustNeighborhoods, a security trust visualization for situational awareness on the Internet aimed at novice and intermediate users of a distributed file sharing system. The TrustNeighborhoods technique uses the metaphor of a multi-layered city or fortress to intuitively represent trust as a simple geographic relation. The visualization uses a radial space-filling layout; there is a 2D mode for editing and configuration, as well as a 3D mode for exploration and overview. In addition, the 3D mode supports a simple animated "fly-to" command that is intended to show the user the context and trust of a particular document by zooming in on the document and its immediate neighborhood in the 3D city. The visualization is intended for integration into an existing desktop environment, connecting to the distributed file sharing mechanisms of the environment and non-obtrusively displaying a 3D orientation animation in the background for any file being accessed over the network. A formal user study shows that the technique supports significantly higher trust assignment accuracy than manual trust assignment at the cost of only a minor time investment. | false | false | [
"Niklas Elmqvist",
"Philippas Tsigas"
] | [] | [] | [] |
EuroVis | 2,007 | Viewpoint Selection for Intervention Planning | 10.2312/VisSym/EuroVis07/267-274 | Viewpoint selection is crucial for medical intervention planning. The interactive exploration of a scene with 3d objects involves the systematic analysis of several anatomic structures. Viewpoint selection techniques enhance the display of the currently selected structure. For animations in collaborative intervention planning and surgical education, the authoring process may be significantly enhanced if 'good' viewpoints for important objects as well as for the whole scene are chosen automatically. We describe a viewpoint selection technique guided by parameters like size of unoccluded surface, importance of occluding objects, preferred region and viewpoint stability. The influence of these parameters may be flexibly adjusted by weights. Parameter maps indicate the influence of the current parameter settings on the viewpoints. For selected applications, the weights may be predefined and reused for other cases. We also describe an informal user study which was accomplished to understand if our viewpoint selection strategies produce adequate results from the users' point of view. | false | false | [
"Konrad Mühler",
"Mathias Neugebauer",
"Christian Tietjen",
"Bernhard Preim"
] | [] | [] | [] |
EuroVis | 2,007 | Visualization Methods for Vortex Rings and Vortex Breakdown Bubbles | 10.2312/VisSym/EuroVis07/211-218 | Vortex breakdown bubbles are a subject which is of interest in many disciplines such as aeronautics, mixing, and combustion. Existing visualization methods are based on stream surfaces, direct volume rendering, tensor field visualization, and vector field topology. This paper presents a topological approach which is more closely oriented at the underlying theory of continuous dynamical systems. Algorithms are described for the detection of vortex rings and vortex breakdown bubbles, and for visualization of their characteristic properties such as the boundary, the chaotic dynamics, and possible islands of stability. Since some of these require very long streamlines, the effect of numerically introduced divergence has to be considered. From an existing subdivision scheme, a novel method for divergence conserving interpolation of cuboid cells is derived, and results are compared with those from standard trilinear interpolation. Also a comparison of results obtained with and without divergence cleaning is given. | false | false | [
"Ronald Peikert",
"Filip Sadlo"
] | [] | [] | [] |
EuroVis | 2,007 | Visualization of Uncertainty in Lattices to Support Decision-Making | 10.2312/VisSym/EuroVis07/051-058 | Lattice graphs are used as underlying data structures in many statistical processing systems, including natural language processing. Lattices compactly represent multiple possible outputs and are usually hidden from users. We present a novel visualization intended to reveal the uncertainty and variability inherent in statistically-derived lattice structures. Applications such as machine translation and automated speech recognition typically present users with a best-guess about the appropriate output, with apparent complete confidence. Through case studies we show how our visualization uses a hybrid layout along with varying transparency, colour, and size to reveal the lattice structure, expose the inherent uncertainty in statistical processing, and help users make better-informed decisions about statistically-derived outputs. | false | false | [
"Christopher Collins 0001",
"Sheelagh Carpendale",
"Gerald Penn"
] | [] | [] | [] |
CHI | 2,007 | An empirical study of the use of visually enhanced voip audio conferencing: the case of IEAC | 10.1145/1240624.1240780 | IBM Enhanced Audio Conferencing (IEAC) is a VoIP-based audio conferencing system that, like several other systems, provides a visualization showing who is present and their states (e.g., speaking, muted). This paper presents the first study of the use of such a system. Drawing on log files collected over six weeks of use by over 1300 corporate employees, and interviews with 10 of them, we look at how and why various features of the system are used and what sorts of practices are supported. Our findings shed light on the factors that drive the use of visual enhancements to audio conferencing, and suggest further research topics. | false | false | [
"Xianghua Ding",
"Thomas Erickson",
"Wendy A. Kellogg",
"Stephen Levy",
"Jim Christensen",
"Jeremy B. Sussman",
"Tracee Vetting Wolf",
"William E. Bennett"
] | [] | [] | [] |
CHI | 2,007 | Beyond visual acuity: the perceptual scalability of information visualizations for large displays | 10.1145/1240624.1240639 | The scalability of information visualizations has typically been limited by the number of available display pixels. As displays become larger, the scalability limit may shift away from the number of pixels and toward human perceptual abilities. This work explores the effect of using large, high resolution displays to scale up information visualizations beyond potential visual acuity limitations. Displays that are beyond visual acuity require physical navigation to see all of the pixels. Participants performed various information visualization tasks using display sizes with a sufficient number of pixels to be within, equal to, or beyond visual acuity. Results showed that performance on most tasks was more efficient and sometimes more accurate because of the additional data that could be displayed, despite the physical navigation that was required. Visualization design issues on large displays are also discussed. | false | false | [
"Beth Yost",
"Yonca Haciahmetoglu",
"Chris North 0001"
] | [] | [] | [] |
CHI | 2,007 | CAAD: an automatic task support system | 10.1145/1240624.1240731 | Recent HCI research shows strong interest in task management systems (e.g. [19, 27]) that support the multi-tasked nature of information work [13]. These systems either require users to manually create and maintain task representations or they depend on explicit user cues to guide the creation and maintenance process. To access and use the task representations in these systems, users must also specify their current task. This interaction overhead inhibits the adoption of these systems. In this paper, we present a novel approach to task management that automates the creation and maintenance of task representations. Our system supports the user by making commonly used information more "ready-at-hand" through an intuitive visualization of their task representations. Users can correct and organize their task representations by directly manipulating the visualization; however, this interaction is not required. We describe a feasibility study that demonstrates the actual utility (in terms of overhead reduction) and perceived utility of our system. | false | false | [
"Tye Rattenbury",
"John F. Canny"
] | [] | [] | [] |
CHI | 2,007 | ExperiScope: an analysis tool for interaction data | 10.1145/1240624.1240826 | We present ExperiScope, an analytical tool to help designers and experimenters explore the results of quantitative evaluations of interaction techniques. ExperiScope combines a new visualization incorporating aspects of the KLM and the three-state model with an interface helping users to rapidly cluster similar patterns of interactions. The tool makes it easy to identify and compare key patterns of use encountered during data collection. This promotes a deeper understanding of the results of a given evaluation.We illustrate the advantages of this tool by revisiting the data collected for an experiment conducted by Hinckley et al. [19] which compared different mode switching techniques. Our results show that our tool complements the previously reported results by offering insights about error behavior and the impact of mode switching on user performance.By providing a more fine-grained analysis of the data gathered during empirical evaluations, we hope that our tool will improve researchers' understanding of existing and newly developed interaction techniques. | false | false | [
"François Guimbretière",
"Morgan Dixon",
"Ken Hinckley"
] | [] | [] | [] |
CHI | 2,007 | FASTDash: a visual dashboard for fostering awareness in software teams | 10.1145/1240624.1240823 | Software developers spend significant time gaining and maintaining awareness of fellow developers' activities. FASTDash is a new interactive visualization that seeks to improve team activity awareness using a spatial representation of the shared code base that highlights team members' current activities. With FASTDash, a developer can quickly determine which team members have source files checked out, which files are being viewed, and what methods and classes are currently being changed. The visualization can be annotated, allowing programmers to supplement activity information with additional status details. It provides immediate awareness of potential conflict situations, such as two programmers editing the same source file. FASTDash was developed through user-centered design, including surveys, team interviews, and in situ observation. Results from a field study show that FASTDash improved team awareness, reduced reliance on shared artifacts, and increased project-related communication. Additionally, the team that participated in our field study continues to use FASTDash. | false | false | [
"Jacob T. Biehl",
"Mary Czerwinski",
"Greg Smith",
"George G. Robertson"
] | [] | [] | [] |
CHI | 2,007 | Improving recognition and characterization in groupware with rich embodiments | 10.1145/1240624.1240627 | Embodiments are visual representations of people in a groupware system. Embodiments convey awareness information such as presence, location, and movement -- but they provide far less information than what is available from a real body in a face-to-face setting. As a result, it is often difficult to recognize and characterize other people in a groupware system without extensive communication. To address this problem, information-rich embodiments use ideas from multivariate information visualization to maximize the amount of information that is represented about a person. To investigate the feasibility of rich embodiment and their effects on group interaction, we carried out three studies. The first shows that users are able to recall and interpret a large set of variables that are graphically encoded on an embodiment. The second and third studies demonstrated rich embodiments in two groupware systems -- a multiplayer game and a drawing application -- and showed that the enhanced representations do improve recognition and characterization, and that they can enrich interaction in a variety of ways. | false | false | [
"Tadeusz Stach",
"Carl Gutwin",
"David Pinelle",
"Pourang Irani"
] | [] | [] | [] |
CHI | 2,007 | Let's go to the whiteboard: how and why software developers use drawings | 10.1145/1240624.1240714 | Software developers are rooted in the written form of their code, yet they often draw diagrams representing their code. Unfortunately, we still know little about how and why they create these diagrams, and so there is little research to inform the design of visual tools to support developers' work. This paper presents findings from semi-structured interviews that have been validated with a structured survey. Results show that most of the diagrams had a transient nature because of the high cost of changing whiteboard sketches to electronic renderings. Diagrams that documented design decisions were often externalized in these temporary drawings and then subsequently lost. Current visualization tools and the software development practices that we observed do not solve these issues, but these results suggest several directions for future research. | false | false | [
"Mauro Cherubini",
"Gina Venolia",
"Robert DeLine",
"Amy J. Ko"
] | [] | [] | [] |
CHI | 2,007 | Perception of elementary graphical elements in tabletop and multi-surface environments | 10.1145/1240624.1240701 | Information shown on a tabletop display can appear distorted when viewed by a seated user. Even worse, the impact of this distortion is different depending on the location of the information on the display. In this paper, we examine how this distortion affects the perception of the basic graphical elements of information visualization shown on displays at various angles. We first examine perception of these elements on a single display, and then compare this to perception across displays, in order to evaluate the effectiveness of various elements for use in a tabletop and multi-display environment. We found that the perception of some graphical elements is more robust to distortion than others. We then develop recommendations for building data visualizations for these environments. | false | false | [
"Daniel Wigdor",
"Chia Shen",
"Clifton Forlines",
"Ravin Balakrishnan"
] | [] | [] | [] |
CHI | 2,007 | Seconds matter: improving distributed coordination bytracking and visualizing display trajectories | 10.1145/1240624.1240822 | Pauses in distributed groupware activity can indicate anything from technical latency through infrastructure failure to a participant's thoughtful contemplation. Unraveling these ambiguities highlights mismatches between unseen off-screen activities and on-screen cursor behaviors. In this paper we suggest that groupware systems have typically been poor at representing off-screen activities, and introduce the concept of display trajectories to bridge the sensor gap between the display and its surrounding space. We consider requirements for display trajectories using the distributed social scientific analysis of video data as an example domain. Drawing on these requirements, we prototype a freeform whiteboard pen tracking and visualization technique around displays using ultrasound. We describe an experiment which inspects the impact of display trajectories on remote response efficiency. Our findings show that visualization of the display trajectory improves participants' ability to coordinate their actions by one second per interaction turn, reducing latency in organizing turn taking by a 'standard maximum' conversation pause. | false | false | [
"Mike Fraser 0001",
"Michael R. McCarthy",
"Muneeb Shaukat",
"Phillip Smith"
] | [] | [] | [] |
CHI | 2,007 | Senspectra: a computationally augmented physical modeling toolkit for sensing and visualization of structural strain | 10.1145/1240624.1240744 | We present Senspectra, a computationally augmented physical modeling toolkit designed for sensing and visualization of structural strain. Senspectra seeks to explore a new direction in computational materiality, incorporating the material quality of malleable elements of an interface into its digital control structure. The system functions as a decentralized sensor network consisting of nodes, embedded with computational capabilities and a full spectrum LED, and flexible joints. Each joint functions as an omnidirectional bend sensing mechanism to sense and communicate mechanical strain between neighboring nodes. Using Senspectra, a user incrementally assembles and refines a physical 3D model of discrete elements with a real-time visualization of structural strain. While the Senspectra infrastructure provides a flexible modular sensor network platform, its primary application derives from the need to couple physical modeling techniques utilized in architecture and design disciplines with systems for structural engineering analysis. This offers direct manipulation augmented with visual feedback for an intuitive approach to physical real-time finite element analysis, particularly for organic forms. | false | false | [
"Vincent Leclerc",
"Amanda J. Parkes",
"Hiroshi Ishii 0001"
] | [] | [] | [] |
CHI | 2,007 | Task and social visualization in software development: evaluation of a prototype | 10.1145/1240624.1240716 | As open source development has evolved, differentiation of roles and increased sophistication of collaborative processes has occurred. Recently, we described coordination issues in software development and an interactive visualization tool called the Social Health Overview (SHO) developed to address them [12]. This paper presents an empirical evaluation of SHO intended to identify its strengths and weaknesses. Eleven informants in various open source roles were interviewed about their work practices. Eight of these participated in an evaluation comparing three change management tasks in SHO and Bugzilla. Results are discussed with respect to task strategy with each tool and participants' roles. | false | false | [
"Jason B. Ellis",
"Shahtab Wahid",
"Catalina Danis",
"Wendy A. Kellogg"
] | [] | [] | [] |
CHI | 2,007 | Voyagers and voyeurs: supporting asynchronous collaborative information visualization | 10.1145/1240624.1240781 | This paper describes mechanisms for asynchronous collaboration in the context of information visualization, recasting visualizations as not just analytic tools, but social spaces. We contribute the design and implementation of sense.us, a web site supporting asynchronous collaboration across a variety of visualization types. The site supports view sharing, discussion, graphical annotation, and social navigation and includes novel interaction elements. We report the results of user studies of the system, observing emergent patterns of social data analysis, including cycles of observation and hypothesis, and the complementary roles of social navigation and data-driven exploration. | false | false | [
"Jeffrey Heer",
"Fernanda B. Viégas",
"Martin Wattenberg"
] | [] | [] | [] |
CHI | 2,007 | White rooms and morphing don't mix: setting and the evaluation of visualization techniques | 10.1145/1240624.1240640 | The results presented in this paper illustrate how a specific map visualization technique is sensitive to setting: a comparative evaluation of the technique gives conflicting results depending on where it takes place. While prior research has explored the impact of factors other than basic visual perception on visualization techniques, relatively little attention has been directed toward the physical setting in which the technique is used. We present results from a study involving 120 participants, comparing the effectiveness of two different geovisualization techniques in promoting recall of map layout. Recall was shown to be sensitive to setting, such that one technique in particular was more effective in a noisy public space than in a controlled, 'white-room' environment. The results have implications for the validation and measurement of information visualization techniques as a whole, and in particular for those employing motion as a communicative attribute. | false | false | [
"Derek F. Reilly",
"Kori M. Inkpen"
] | [] | [] | [] |
Vis | 2,006 | A Generic and Scalable Pipeline for GPU Tetrahedral Grid Rendering | 10.1109/TVCG.2006.110 | Recent advances in algorithms and graphics hardware have opened the possibility to render tetrahedral grids at interactive rates on commodity PCs. This paper extends on this work in that it presents a direct volume rendering method for such grids which supports both current and upcoming graphics hardware architectures, large and deformable grids, as well as different rendering options. At the core of our method is the idea to perform the sampling of tetrahedral elements along the view rays entirely in local barycentric coordinates. Then, sampling requires minimum GPU memory and texture access operations, and it maps efficiently onto a feed-forward pipeline of multiple stages performing computation and geometry construction. We propose to spawn rendered elements from one single vertex. This makes the method amenable to upcoming Direct3D 10 graphics hardware which allows to create geometry on the GPU. By only modifying the algorithm slightly it can be used to render per-pixel iso-surfaces and to perform tetrahedral cell projection. As our method neither requires any pre-processing nor an intermediate grid representation it can efficiently deal with dynamic and large 3D meshes | false | false | [
"Joachim Georgii",
"Rüdiger Westermann"
] | [] | [] | [] |
Vis | 2,006 | A Novel Visualization Model for Web Search Results | 10.1109/TVCG.2006.111 | This paper presents an interactive visualization system, named WebSearchViz, for visualizing the Web search results and facilitating users' navigation and exploration. The metaphor in our model is the solar system with its planets and asteroids revolving around the sun. Location, color, movement, and spatial distance of objects in the visual space are used to represent the semantic relationships between a query and relevant Web pages. Especially, the movement of objects and their speeds add a new dimension to the visual space, illustrating the degree of relevance among a query and Web search results in the context of users' subjects of interest. By interacting with the visual space, users are able to observe the semantic relevance between a query and a resulting Web page with respect to their subjects of interest, context information, or concern. Users' subjects of interest can be dynamically changed, redefined, added, or deleted from the visual space | false | false | [
"Tien Nguyen",
"Jun Zhang"
] | [] | [] | [] |
Vis | 2,006 | A Pipeline for Computer Aided Polyp Detection | 10.1109/TVCG.2006.112 | We present a novel pipeline for computer-aided detection (CAD) of colonic polyps by integrating texture and shape analysis with volume rendering and conformal colon flattening. Using our automatic method, the 3D polyp detection problem is converted into a 2D pattern recognition problem. The colon surface is first segmented and extracted from the CT data set of the patient's abdomen, which is then mapped to a 2D rectangle using conformal mapping. This flattened image is rendered using a direct volume rendering technique with a translucent electronic biopsy transfer function. The polyps are detected by a 2D clustering method on the flattened image. The false positives are further reduced by analyzing the volumetric shape and texture features. Compared with shape based methods, our method is much more efficient without the need of computing curvature and other shape parameters for the whole colon surface. The final detection results are stored in the 2D image, which can be easily incorporated into a virtual colonoscopy (VC) system to highlight the polyp locations. The extracted colon surface mesh can be used to accelerate the volumetric ray casting algorithm used to generate the VC endoscopic view. The proposed automatic CAD pipeline is incorporated into an interactive VC system, with a goal of helping radiologists detect polyps faster and with higher accuracy | false | false | [
"Wei Hong 0006",
"Feng Qiu",
"Arie E. Kaufman"
] | [] | [] | [] |
Vis | 2,006 | A Spectral Analysis of Function Composition and its Implications for Sampling in Direct Volume Visualization | 10.1109/TVCG.2006.113 | In this paper we investigate the effects of function composition in the form g(f(x)) = h(x) by means of a spectral analysis of h. We decompose the spectral description of h(x) into a scalar product of the spectral description of g(x) and a term that solely depends on f(x) and that is independent of g(x). We then use the method of stationary phase to derive the essential maximum frequency of g(f(x)) bounding the main portion of the energy of its spectrum. This limit is the product of the maximum frequency of g(x) and the maximum derivative of f(x). This leads to a proper sampling of the composition h of the two functions g and f. We apply our theoretical results to a fundamental open problem in volume rendering - the proper sampling of the rendering integral after the application of a transfer function. In particular, we demonstrate how the sampling criterion can be incorporated in adaptive ray integration, visualization with multi-dimensional transfer functions, and pre-integrated volume rendering | false | false | [
"Steven Bergner",
"Torsten Möller",
"Daniel Weiskopf",
"David J. Muraki"
] | [] | [] | [] |
Vis | 2,006 | A Trajectory-Preserving Synchronization Method for Collaborative Visualization | 10.1109/TVCG.2006.114 | In the past decade, a lot of research work has been conducted to support collaborative visualization among remote users over the networks, allowing them to visualize and manipulate shared data for problem solving. There are many applications of collaborative visualization, such as oceanography, meteorology and medical science. To facilitate user interaction, a critical system requirement for collaborative visualization is to ensure that remote users would perceive a synchronized view of the shared data. Failing this requirement, the user's ability in performing the desirable collaborative tasks would be affected. In this paper, we propose a synchronization method to support collaborative visualization. It considers how interaction with dynamic objects is perceived by application participants under the existence of network latency, and remedies the motion trajectory of the dynamic objects. It also handles the false positive and false negative collision detection problems. The new method is particularly well designed for handling content changes due to unpredictable user interventions or object collisions. We demonstrate the effectiveness of our method through a number of experiments | false | false | [
"Lewis W. F. Li",
"Frederick W. B. Li",
"Rynson W. H. Lau"
] | [] | [] | [] |
Vis | 2,006 | Ambient Occlusion and Edge Cueing for Enhancing Real Time Molecular Visualization | 10.1109/TVCG.2006.115 | The paper presents a set of combined techniques to enhance the real-time visualization of simple or complex molecules (up to order of 10<sup>6</sup> atoms) space fill mode. The proposed approach includes an innovative technique for efficient computation and storage of ambient occlusion terms, a small set of GPU accelerated procedural impostors for space-fill and ball-and-stick rendering, and novel edge-cueing techniques. As a result, the user's understanding of the three-dimensional structure under inspection is strongly increased (even for'still images), while the rendering still occurs in real time | false | false | [
"Marco Tarini",
"Paolo Cignoni",
"Claudio Montani"
] | [
"TT"
] | [] | [] |
Vis | 2,006 | An Advanced Evenly-Spaced Streamline Placement Algorithm | 10.1109/TVCG.2006.116 | This paper presents an advanced evenly-spaced streamline placement algorithm for fast, high-quality, and robust layout of flow lines. A fourth-order Runge-Kutta integrator with adaptive step size and error control is employed for rapid accurate streamline advection. Cubic Hermite polynomial interpolation with large sample-spacing is adopted to create fewer evenly-spaced samples along each streamline to reduce the amount of distance checking. We propose two methods to enhance placement quality. Double queues are used to prioritize topological seeding and to favor long streamlines to minimize discontinuities. Adaptive distance control based on the local flow variance is explored to reduce cavities. Furthermore, we propose a universal, effective, fast, and robust loop detection strategy to address closed and spiraling streamlines. Our algorithm is an order-of-magnitude faster than Jobard and Lefer's algorithm with better placement quality and over 5 times faster than Mebarki et al.'s algorithm with comparable placement quality, but with a more robust solution to loop detection | false | false | [
"Zhanping Liu",
"Robert J. Moorhead II",
"Joe Groner"
] | [] | [] | [] |
Vis | 2,006 | An Atmospheric Visual Analysis and Exploration System | 10.1109/TVCG.2006.117 | Meteorological research involves the analysis of multi-field, multi-scale, and multi-source data sets. Unfortunately, traditional atmospheric visualization systems only provide tools to view a limited number of variables and small segments of the data. These tools are often restricted to 2D contour or vector plots or 3D isosurfaces. The meteorologist must mentally synthesize the data from multiple plots to glean the information needed to produce a coherent picture of the weather phenomenon of interest. In order to provide better tools to meteorologists and reduce system limitations, we have designed an integrated atmospheric visual analysis and exploration system for interactive analysis of weather data sets. Our system allows for the integrated visualization of 1D, 2D, and 3D atmospheric data sets in common meteorological grid structures and utilizes a variety of rendering techniques. These tools provide meteorologists with new abilities to analyze their data and answer questions on regions of interest, ranging from physics-based atmospheric rendering to illustrative rendering containing particles and glyphs. In this paper, we discuss the use and performance of our visual analysis for two important meteorological applications. The first application is warm rain formation in small cumulus clouds. In this, our three-dimensional, interactive visualization of modeled drop trajectories within spatially correlated fields from a cloud simulation has provided researchers with new insight. Our second application is improving and validating severe storm models, specifically the weather research and forecasting (WRF) model. This is done through correlative visualization of WRF model and experimental Doppler storm data | false | false | [
"Yuyan Song",
"Jing Ye",
"Nikolai A. Svakhine",
"Sonia Lasher-Trapp",
"Mike Baldwin",
"David S. Ebert"
] | [] | [] | [] |
Vis | 2,006 | Analyzing Complex FTMS Simulations: a Case Study in High-Level Visualization of Ion Motions | 10.1109/TVCG.2006.118 | Current practice in particle visualization renders particle position data directly onto the screen as points or glyphs. Using a camera placed at a fixed position, particle motions can be visualized by rendering trajectories or by animations. Applying such direct techniques to large, time dependent particle data sets often results in cluttered images in which the dynamic properties of the underlying system are difficult to interpret. In this case study we take an alternative approach to the visualization of ion motions. Instead of rendering ion position data directly, we first extract meaningful motion information from the ion position data and then map this information onto geometric primitives. Our goal is to produce high-level visualizations that reflect the physicists' way of thinking about ion dynamics. Parameterized geometric icons are defined to encode motion information of clusters of related ions. In addition, a parameterized camera control mechanism is used to analyze relative instead of only absolute ion motions. We apply the techniques to simulations of Fourier transform mass spectrometry (FTMS) experiments. The data produced by such simulations can amount to 5.10<sup>4</sup> ions and 10<sup>5</sup> timesteps. This paper discusses the requirements, design and informal evaluation of the implemented system | false | false | [
"Wojciech Burakiewicz",
"Robert van Liere"
] | [] | [] | [] |
Vis | 2,006 | Analyzing Vortex Breakdown Flow Structures by Assignment of Colors to Tensor Invariants | 10.1109/TVCG.2006.119 | Topological methods are often used to describe flow structures in fluid dynamics and topological flow field analysis usually relies on the invariants of the associated tensor fields. A visual impression of the local properties of tensor fields is often complex and the search of a suitable technique for achieving this is an ongoing topic in visualization. This paper introduces and assesses a method of representing the topological properties of tensor fields and their respective flow patterns with the use of colors. First, a tensor norm is introduced, which preserves the properties of the tensor and assigns the tensor invariants to values of the RGB color space. Secondly, the RGB colors of the tensor invariants are transferred to corresponding hue values as an alternative color representation. The vectorial tensor invariants field is reduced to a scalar hue field and visualization of iso-surfaces of this hue value field allows us to identify locations with equivalent flow topology. Additionally highlighting by the maximum of the eigenvalue difference field reflects the magnitude of the structural change of the flow. The method is applied on a vortex breakdown flow structure inside a cylinder with a rotating lid | false | false | [
"Markus Rütten",
"Min S. Chong"
] | [] | [] | [] |
Vis | 2,006 | Asynchronous Distributed Calibration for Scalable and Reconfigurable Multi-Projector Displays | 10.1109/TVCG.2006.121 | Centralized techniques have been used until now when automatically calibrating (both geometrically and photometrically) large high-resolution displays created by tiling multiple projectors in a 2D array. A centralized server managed all the projectors and also the camera(s) used to calibrate the display. In this paper, we propose an asynchronous distributed calibration methodology via a display unit called the plug-and-play projector (PPP). The PPP consists of a projector, camera, computation and communication unit, thus creating a self-sufficient module that enables an asynchronous distributed architecture for multi-projector displays. We present a single-program-multiple-data (SPMD) calibration algorithm that runs on each PPP and achieves a truly scalable and reconfigurable display without any input from the user. It instruments novel capabilities like adding/removing PPPs from the display dynamically, detecting faults, and reshaping the display to a reasonable rectangular shape to react to the addition/removal/faults. To the best of our knowledge, this is the first attempt to realize a completely asynchronous and distributed calibration architecture and methodology for multi-projector displays | false | false | [
"Ezekiel S. Bhasker",
"Pinaki Sinha",
"Aditi Majumder"
] | [] | [] | [] |
Vis | 2,006 | Caricaturistic Visualization | 10.1109/TVCG.2006.123 | Caricatures are pieces of art depicting persons or sociological conditions in a non-veridical way. In both cases caricatures are referring to a reference model. The deviations from the reference model are the characteristic features of the depicted subject. Good caricatures exaggerate the characteristics of a subject in order to accent them. The concept of caricaturistic visualization is based on the caricature metaphor. The aim of caricaturistic visualization is an illustrative depiction of characteristics of a given dataset by exaggerating deviations from the reference model. We present the general concept of caricaturistic visualization as well as a variety of examples. We investigate different visual representations for the depiction of caricatures. Further, we present the caricature matrix, a technique to make differences between datasets easily identifiable | false | false | [
"Peter Rautek",
"Ivan Viola",
"M. Eduard Gröller"
] | [] | [] | [] |
Vis | 2,006 | ClearView: An Interactive Context Preserving Hotspot Visualization Technique | 10.1109/TVCG.2006.124 | Volume rendered imagery often includes a barrage of 3D information like shape, appearance and topology of complex structures, and it thus quickly overwhelms the user. In particular, when focusing on a specific region a user cannot observe the relationship between various structures unless he has a mental picture of the entire data. In this paper we present ClearView, a GPU-based, interactive framework for texture-based volume ray-casting that allows users which do not have the visualization skills for this mental exercise to quickly obtain a picture of the data in a very intuitive and user-friendly way. ClearView is designed to enable the user to focus on particular areas in the data while preserving context information without visual clutter. ClearView does not require additional feature volumes as it derives any features in the data from image information only. A simple point-and-click interface enables the user to interactively highlight structures in the data. ClearView provides an easy to use interface to complex volumetric data as it only uses transparency in combination with a few specific shaders to convey focus and context information | false | false | [
"Jens H. Krüger",
"Jens Schneider 0002",
"Rüdiger Westermann"
] | [] | [] | [] |
Vis | 2,006 | Comparative Visualization for Wave-based and Geometric Acoustics | 10.1109/TVCG.2006.125 | We present a comparative visualization of the acoustic simulation results obtained by two different approaches that were combined into a single simulation algorithm. The first method solves the wave equation on a volume grid based on finite elements. The second method, phonon tracing, is a geometric approach that we have previously developed for interactive simulation, visualization and modeling of room acoustics. Geometric approaches of this kind are more efficient than FEM in the high and medium frequency range. For low frequencies they fail to represent diffraction, which on the other hand can be simulated properly by means of FEM. When combining both methods we need to calibrate them properly and estimate in which frequency range they provide comparable results. For this purpose we use an acoustic metric called gain and display the resulting error. Furthermore we visualize interference patterns, since these depend not only on diffraction, but also exhibit phase-dependent amplification and neutralization effects | false | false | [
"Eduard Deines",
"Martin Hering-Bertram",
"Jan Mohring",
"Jevgenijs Jegorovs",
"Frank Michel 0001",
"Hans Hagen",
"Gregory M. Nielson"
] | [] | [] | [] |
Vis | 2,006 | Composite Rectilinear Deformation for Stretch and Squish Navigation | 10.1109/TVCG.2006.127 | We present the first scalable algorithm that supports the composition of successive rectilinear deformations. Earlier systems that provided stretch and squish navigation could only handle small datasets. More recent work featuring rubber sheet navigation for large datasets has focused on rendering and on application-specific issues. However, no algorithm has yet been presented for carrying out such navigation methods; our paper addresses this problem. For maximum flexibility with large datasets, a stretch and squish navigation algorithm should allow for millions of potentially deformable regions. However, typical usage only changes the extents of a small subset k of these n regions at a time. The challenge is to avoid computations that are linear in n, because a single deformation can affect the absolute screen-space location of every deformable region. We provide an O(klogn) algorithm that supports any application that can lay out a dataset on a generic grid, and show an implementation that allows navigation of trees and gene sequences with millions of items in sub-millisecond time | false | false | [
"James Slack",
"Tamara Munzner"
] | [] | [] | [] |
Vis | 2,006 | Concurrent Visualization in a Production Supercomputing Environment | 10.1109/TVCG.2006.128 | We describe a concurrent visualization pipeline designed for operation in a production supercomputing environment. The facility was initially developed on the NASA Ames "Columbia" supercomputer for a massively parallel forecast model (GEOS4). During the 2005 Atlantic hurricane season, GEOS4 was run 4 times a day under tight time constraints so that its output could be included in an ensemble prediction that was made available to forecasters at the National Hurricane Center. Given this time-critical context, we designed a configurable concurrent pipeline to visualize multiple global fields without significantly affecting the runtime model performance or reliability. We use MPEG compression of the accruing images to facilitate live low-bandwidth distribution of multiple visualization streams to remote sites. We also describe the use of our concurrent visualization framework with a global ocean circulation model, which provides a 864-fold increase in the temporal resolution of practically achievable animations. In both the atmospheric and oceanic circulation models, the application scientists gained new insights into their model dynamics, due to the high temporal resolution animations attainable | false | false | [
"David Ellsworth",
"Bryan Green",
"Chris Henze",
"Patrick J. Moran",
"Timothy Sandstrom"
] | [] | [] | [] |
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