IVAPP 2013 Abstracts


Area 1 - Spatial Data Visualization

Full Papers
Paper Nr: 3
Title:

Color Visualization of 2D Segmentations

Authors:

Christoph Dalitz, Tobias Bolten and Oliver Christen

Abstract: This paper deals with the problem of coloring a two-dimensional segmentation result in such a way that each segment has a different color with the constraint that adjacent segments have sufficiently distinct colors to be easily distinguishable by a human viewer. Our solution for this problem is based on a balanced coloring of the neighborhood graph built from the area Voronoi diagram. The balanced coloring with only a limited number of colors is subsequently modified to assign each segment a unique color. For picking the initial palette of evenly distributed colors, we propose a method that is based on the physical analogy of energy minimization in a Wigner crystal. To make the energy formula applicable to arbitrary color spaces and distance measures, we give generalized definitions for the center and radius of a color space with an arbitrary distance metric. The individual steps of our coloring algorithm have been evaluated on the PRIMA dataset.

Paper Nr: 6
Title:

Visualizing Temporal Behavior in Multifield Particle Simulations

Authors:

T. S. Reis Santos, F. V. Paulovich, V. Molchanov, L. Linsen and M. C. F. de Oliveira

Abstract: Particle-based simulations generate time-varying multifield volumetric datasets. Visualizations of such volumes traditionally focus on the physical space, displaying particles as glyphs or with volume rendering techniques. In this paper we deal specifically with the issue of helping users to observe and interpret the multidimensional feature space and its temporal behavior, as a complement to existing spatial views. Our approach combines multiple visualizations to assist analysis of time-varying data generated by particle simulations. Coordinated views of both feature and physical spaces allow the observation of particle behavior over specific time periods or the whole temporal domain, rather than describing a single simulation time step. Temporal behavior in the physical space is depicted as pathlines, whereas the temporal behavior of the underlying multidimensional feature space is depicted in a so-called streamfeature visualization. Streamfeatures are pathlines describing changes in feature space along time, obtained by projecting the feature vectors. Direct interaction with these line representations is difficult. Thus, two supporting views are supplied for user interaction, which show 2D projections of both the pathlines (pathline projection view) and the streamfeatures (streamfeature projection view), obtained by projecting geometric features extracted from the lines. By linking all visualizations, users may interact with these views to identify and select representative clusters of lines that reflect similar behavior of particle features. We use data from two particle simulations to illustrate the framework and its potential to support analysis of global temporal behavior and relationships between multiple variables.

Area 2 - Abstract Data Visualization

Full Papers
Paper Nr: 11
Title:

A Study on the Role of Similarity Measures in Visual Text Analytics

Authors:

F. San Roman S., R. D. de Pinho, R. Minghim and M. C. F. de Oliveira

Abstract: Text Analytics is essential for a large number of applications and good approaches to obtain visual mappings of text are paramount. Many visualization techniques, such as similarity based point placement layouts, have proved useful to support visual analysis of documents. However, they are sensitive to data quality, which, in turn, relies on a critical preprocessing step that involves text cleaning and in some cases term detecting and weighting, as well as the definition of a similarity function. Not much has been discussed on the effect of these important similarity calculations in the quality of visual representations. This paper presents a study on the role of different text similarity measurements on the generation of visual text mappings. We focus mainly on two types of distance functions, those based on the well-known text vector representation and on direct string comparison measurements, comparing their effect on visual mappings obtained with point placement techniques. We find that both have their value but, in many circumstances, the vector space model (VSM) is the best solution when discrimination is important. However, the VSM is not incremental, that is, new additions to a collection force a recalculation of the whole feature space and similarities. In this work we also propose a new incremental model based on the VSM, which is shown to present the best visualization results in many configurations tested. We show the evaluation results and offer recommendations on the application of different text similarity measurements for Visual Text Analytics tasks.

Paper Nr: 17
Title:

WebComets: A Tab-Oriented Approach for Browser History Visualization

Authors:

Daniel Cernea, Igor Truderung, Andreas Kerren and Achim Ebert

Abstract: Web browsers are our main gateways to the Internet. With their help we read articles, we learn, we listen to music, we share our thoughts and feelings, we write e-mails, or we chat. Current Web browser histories have mostly no visualization capabilities as well as limited options to filter patterns and information. Furthermore, such histories disregard the existence of parallel navigation in multiple browser windows and tabs. But a good understanding of parallel browsing behavior is of critical importance for the casual user and the behavioural analyst, while at the same time having implications in the design of search engines, Web sites and Web browsers. In this paper we present WebComets, an interactive visualization for extended browser histories. Our visualization employs browser histories that capture—among others—the tab-oriented, parallel nature of Web page navigation. Results presented in this paper suggest that WebComets better supports the analysis and comparison of parallel browsing and corresponding behavior patterns than common browser histories.

Area 3 - General Data Visualization

Full Papers
Paper Nr: 20
Title:

MolMap - Visualizing Molecule Libraries as Topographic Maps

Authors:

Martin Gronemann, Michael Jünger, Nils Kriege and Petra Mutzel

Abstract: We present a new application for graph drawing and visualization in the context of drug discovery. Combining the scaffold-based cluster hierarchy with molecular similarity graphs—both standard concepts in cheminformatics — allows one to get new insights for analyzing large molecule libraries. The derived clustered graphs represent different aspects of structural similarity. We suggest visualizing them as topographic maps. Since the cluster hierarchy does not reflect the underlying graph structure as in (Gronemann and Jünger, 2012), we suggest a new partitioning algorithm that takes the edges of the graph into account. Experiments show that the new algorithm leads to significant improvements in terms of the edge lengths in the obtained drawings.

Area 4 - Abstract Data Visualization

Full Papers
Paper Nr: 21
Title:

Telecommunications Customers Churn Monitoring using Flow Maps and Cartogram Visualization

Authors:

David L. García, Àngela Nebot and Alfredo Vellido

Abstract: Telecommunication companies compete in increasingly aggressive markets. Avoiding customer defection, or churn, should be at the core of successful management in such context. These companies store and manage abundant customer usage data. Their analysis using advanced techniques can be a source of valuable insight into customers’ behavior over time. Exploratory data visualization can help in this task. Many important contributions to multivariate data visualization using nonlinear techniques have recently been made. In this paper, we analyze a database of customer landline telephone usage in Brazil. These data are first visualized using a nonlinear manifold learning model, Generative Topographic Mapping (GTM). This visualization is enhanced using a cartogram technique, inspired in geographical representation methods, that reintroduces the local nonlinear distortion into the representation space. Yet another geographical information visualization technique, namely the Flow Maps, is then used to visualize customer migrations over time periods in the GTM data representation space. The experimental results shown in this paper provide evidence to support that the use of these methods can assist experts in the process of useful knowledge extraction, with an impact on customer retention management strategies.

Paper Nr: 30
Title:

Visualization of Large Ontologies with Landmarks

Authors:

Zong Lei Jiao, Qiang Liu, Yuan-Fang Li, Kim Marriott and Michael Wybrow

Abstract: Ontologies are building blocks of the Semantic Web and are essential for knowledge representation and data integration. Interactive visualization is an important tool for the understanding of ontologies, especially large ones. In this paper, we present a novel hierarchical ontology visualization method for effectively visualizing an ontology’s global landmarks, local structure and individual class’ details. We have implemented a visualization system that can handle large ontologies efficiently. Preliminary evaluation indicates that the method and the system can be effectively used to understand large ontologies.

Area 5 - General Data Visualization

Full Papers
Paper Nr: 35
Title:

The Inspector - A Cognitive Artefact for Visual Mapping

Authors:

Mohammad A. Kuhail, Soren Lauesen and Kostas Pantazos

Abstract: Existing custom visualization tools provide cognitive artefacts that can reduce the cognitive barriers designers encounter in visual mapping, mapping data to visual primitives (e.g. ellipse, rectangle) and their properties (e.g. colour, size.) However, our experience with designers shows that the existing artefacts are insufficient. In particular, designers struggle to understand the relationship between visual primitives, their properties, and data. Moreover, it is hard to verify the correctness of the visual mappings. In response, we developed a new cognitive artefact, the inspector, that explicitly shows the data behind visual primitive and their properties. We evaluated the impact of the inspector on usability with seven designers. The result shows that the inspector reduced usability problems and helped designers verify the visual mappings.

Area 6 - Abstract Data Visualization

Full Papers
Paper Nr: 38
Title:

Real-time Intelligent Clustering for Graph Visualization

Authors:

Lionel Martin and Géraldine Bous

Abstract: We present a tool for the interactive exploration and analysis of large clustered graphs. The tool empowers users to control the granularity of the graph, either by direct interaction (collapsing/expanding clusters) or via a slider that automatically computes a clustered graph of the desired size. Moreover, we explore the use of learning algorithms to capture graph exploration preferences based on a history of user interactions. The learned parameters are then used to modify the action of the slider in view of mimicking the natural interaction/exploration behavior of the user.

Short Papers
Paper Nr: 8
Title:

Situation Awareness-Oriented Alarm Visualizations: A next Step in HSC Environments

Authors:

Rosa Romero-Gómez, David Díez, Paloma Díaz and Ignacio Aedo

Abstract: Due to their effective capability to fix the attention of control room operators to such conditions that require some kind of response, alarm visualizations have become key control artifacts in Human Supervisory Control environments. Nevertheless, the increasing complexity and interconnectivity of controlled processes highlights the necessity of new control artifacts that support both identification and diagnosis tasks. In this line of work, this paper posits the need of redesigning alarm visualizations in order to assist not only the real-time detection of failures but also the achievement of Situation Awareness by control room operators. Based on dynamic interaction and exploration capabilities, this new design perspective for alarm visualizations may improve the operator’s ability to diagnose the causes of abnormal situations.

Area 7 - Spatial Data Visualization

Short Papers
Paper Nr: 9
Title:

Interactive Visual Intervention Planning - Interactive Visualization for Intervention Planning in Particle Accelerator Environments with Ionizing Radiation

Authors:

Thomas Fabry, Christian Braesch and Bruno Feral

Abstract: Intervention planning is crucial for maintenance operations in particle accelerator environments with ionizing radiation, during which the radiation dose contracted by maintenance workers should be reduced to a minimum. In this context, we discuss the visualization aspects of a new software tool, which integrates interactive exploration of a scene depicting an accelerator facility augmented with residual radiation level simulations, with the visualization of intervention data such as the followed trajectory and maintenance tasks. The visualization of each of these aspects has its effect on the final predicted contracted radiation dose. In this context, we explore the possible benefits of a user study, with the goal of enhancing the visual conditions in which the intervention planner using the software tool is minimizing the radiation dose.

Area 8 - Abstract Data Visualization

Short Papers
Paper Nr: 10
Title:

Data Visualisation and Statistical Analysis within the Decision Making Process

Authors:

Jamie Mahoney

Abstract: Large amounts of data are collected and stored within universities, but little is done to reuse this data to support decision making processes. This paper discusses the use of data visualisation and statistical analysis as methods of making sense of the collected data, analysing it to assess the effects of historical institutional decisions and discusses the use of such techniques to aid decision making processes.

Paper Nr: 15
Title:

A New Interactive Information Visualization Framework based on the Object-oriented Views of Querying and Visualizing Databases

Authors:

Wei Shi and Yuzuru Tanaka

Abstract: In this paper, we propose a new visualization framework which can help users to create highly-customized and interactive visualizations. This framework includes an Object-Oriented View Manipulation Model for querying and manipulating data, as well as an Object-Oriented Visualization Implementation Model for creating visualizations. The visualizations created using our framework allow users to directly manipulate them, which indirectly modifies the tree structures of the two models. Such interactions enable users to visually define an Object-Oriented view for querying the database, to visually create visualizations, and to modify existing visualizations. Users can also interact with the visualization results to filter out their visual objects which do not satisfy the user-specified conditions.

Area 9 - Spatial Data Visualization

Short Papers
Paper Nr: 18
Title:

Uncertainty Visualization and Hole Filling for Geometric Models of Ancient Water Systems

Authors:

Jeffrey Forrester, William McVicker, Timmy Gambin, Christopher Clark and Zoë J. Wood

Abstract: Geometric data acquired via a scanning process can suffer from holes due to errors in the acquisition process, noise, or challenges in merging multiple inputs together into a unified map. We present a straight forward algorithm to fill holes in incomplete evidence grids representing acquired geometric data. We also present our methods to apply learning in order to statistically evaluate the proposed hole filling algorithm. This analysis validates our proposed method for hole filling and additionally enables the construction of a probability distribution function to represent the accuracy of the filled data per model. During surface reconstruction, this function can be used to visualize the certainty of the filled geometry via transparency and coloring giving the user an understanding of the data’s accuracy. This work is motivated by a multi-year project to construct educational visualizations of ancient water storage systems, i.e. cisterns and wells within churches, fortresses and homes on the islands of Malta, Gozo and Sicily.

Paper Nr: 43
Title:

Fast and Efficient Vertex Data Representations for the Web

Authors:

Yvonne Jung, Max Limper, Pasquale Herzig, Karsten Schwenk and Johannes Behr

Abstract: Supporting decision processes via fast and accurate visualization of 3D data is an important aspect in many scientific fields, ranging from mathematics and engineering trough medical data analysis. Due to their high flexibility and platform-independence, 3D Web technologies have become more and more important for such visualization purposes. Within this paper, we concentrate on the accurate rendering of 3D surface models inside Web browsers and show efficient techniques that enable fast and precise visualization and interaction using state-of-the-art Web technologies. We introduce a smart vertex data storage format, which fits very well with the requirements of modern mobile graphics hardware. Furthermore, we discuss methods to partition models of high complexity. Finally, we present an hardware-accelerated picking algorithm that enables a high precision inspection of 3D objects and their vertex attributes.

Area 10 - General Data Visualization

Posters
Paper Nr: 22
Title:

Understanding the Role of Historical Context in a Point of Interest Recommendation System

Authors:

Paulo Pombinho, Ana Paula Afonso and Maria Beatriz Carmo

Abstract: The increasingly large quantities of points of interest make choosing between all the available information a painful task for the users. This limitation is aggravated by the reduced screen space of most mobile devices. To minimize these issues, it is fundamental that the information shown to the user is relevant, helping them in making good choices and decisions. We present a two phase evaluation of an adaptive degree of interest function that uses location and temporal contexts combined with the historical context of the previous searches to quantify the relevance of the points of interest shown to the user.

Paper Nr: 23
Title:

Comparison of Simultaneous Measurement While Viewing Real Objects and 3D Video Clips

Authors:

Tomoki Shiomi, Keita Uemoto, Takehito Kojima, Satoshi Hasegawa, Masako Omori, Hiromu Ishio, Hiroki Takada and Masaru Miyao

Abstract: The use of 3-dimensional images has been spreading rapidly in recent years such as in 3D films and 3D televisions. However, the influence of stereoscopic vision on human visual function remains insufficiently understood. The public has come to understand that lens accommodation and convergence are mismatched while viewing 3D video clips, and this is the main reason for the visual fatigue caused by 3D. The aim in this study is to compare the fixation distance of accommodation and convergence in viewing real objects and 3D video clips. Real objects and 3D video clips perform the same movements. We measured accommodation and convergence in viewing real objects and 3D video clips. From the result of this experiment, we found that no discrepancy exists in viewing 3D video clips like real object. Therefore, we argue that the symptoms in viewing stereoscopic vision may not be due to the discrepancy between lens accommodation and convergence.

Paper Nr: 27
Title:

Knowledge-assisted Visualization in the Cultural Heritage Domain - Case Studies, Needs and Reflections

Authors:

Patricia Martín-Rodilla

Abstract: We investigate on how to build software systems that assist cultural heritage researchers to reconstruct past events on the basis of present data. In this setting, knowledge-assisted visualization can be a useful mechanism to improve the knowledge generation process and emphasise collaboration. However, a useful visualization depends on the goals of the user and the specific research problem involved. In this position paper we present a set of case studies to defend the study of cognitive inferences through discourse analysis and its typologies as a starting point in the knowledge-assisted elicitation process. Once a complete study of usual inferences in the cultural heritage domain is done, the visualization needs in this domain will be easier to determine and apply, attaining our objective of knowledge-assisted visualization.

Area 11 - Abstract Data Visualization

Posters
Paper Nr: 28
Title:

Semantic Visualization in 3D Urban Environment - Taking Text as an Example

Authors:

Fan Zhang, Vincent Tourre and Guillaume Moreau

Abstract: One important aspect of semantic data in computer visualization is to offer supporting and extra information of the environment besides the pure graphical information to system users. It is devoted to help them understand the visualization result better. This paper presents a way to visualize semantic data in 3D urban environment in form of text, which is similar to the issue of 3D labelling and annotation. Different objects in 3D urban environment need different annotation techniques. Occlusions, overlaps, readability, visibility and information density are problems encountered frequently, and several potential solutions are proposed accordingly. A primary test is done to compare the performances among three different text layout techniques: floating text, fading text, linking text. The result shows that floating text and fading text are well understood in a 3D environment, the former one maintaining good readability and visibility and the latter one efficiently avoiding occlusions. Finally several open questions are proposed in the discussion part.

Area 12 - General Data Visualization

Posters
Paper Nr: 29
Title:

Semantic Visualization in Social Network Analysis - A Social Network Analysis Example Built using Tom Sawyer Perspectives

Authors:

Liangrong Yi, Wendy Feng and Brendan Madden

Abstract: With the rapid development of social network websites, the need for social network analysis has been increasing dramatically. Visualization is a very powerful tool in social network analysis. Tom Sawyer Perspectives is an advanced visualization software package and it integrates several visualization techniques including interactive visualization, data filtering, semantic zooming, search, animation and combination of multiple views. We propose to use a composite solution in social network analysis, present a case study of using Tom Sawyer Perspectives and validate its effectiveness.

Paper Nr: 31
Title:

Traffic Visualization - Applying Information Visualization Techniques to Enhance Traffic Planning

Authors:

Matteo Picozzi, Nervo Verdezoto, Matti Pouke, Jarkko Vatjus-Anttila and Aaron Quigley

Abstract: In this paper, we present a space-time visualization to provide city’s decision-makers the ability to analyse and uncover important “city events” in an understandable manner for city planning activities. An interactive Web mashup visualization is presented that integrates several visualization techniques to give a rapid overview of traffic data. We illustrate our approach as a case study for traffic visualization systems, using datasets from the city of Oulu that can be extended to other city planning activities. We also report the feedback of real users (traffic management employees, traffic police officers, city planners) to support our arguments.

Paper Nr: 42
Title:

Towards Interactive Multisensory Data Representations

Authors:

Susanne Tak and Lex Toet

Abstract: Despite the availability of a broad range of newly developed multisensory displays and interaction techniques, multisensory interactive data representations are still not widely used. We argue that for complex information analysis multisensory data representations and multimodal interactivity are essential. By leveraging the benefits of the individual sensory modalities multisensory representations and interaction techniques can make the representation and handling of complex data more intuitive and transparent. This can make complex data analysis accessible to a wider audience, also including non-experts. However, there is currently a lack of agreed guidelines for their integrated design, as well as little empirical research in this area. We argue that there is an urgent need for further systematic research into human multisensory information processing to provide rules that enable the design and construction of representations and interfaces that achieve optimal synergistic cooperation across sensory modalities.