This special section of IEEE Transactions on Visualization and Computer Graphics ( TVCG) presents extended versions of four outstanding papers from the IEEE Pacific Visualization Symposium 2011 (PacificVis 2011) which was held in Hong Kong, China, on 1-4 March 2011. The objective of this annual symposium is to foster greater exchange between visualization researchers and practitioners, and to draw more researchers in the Asia-Pacific region to enter this fascinating and rapidly growing area of research. In only four years, it has become an established forum for visualization, as witnessed by the high quality and breadth of the papers published in the conference proceedings. PacificVis 2011 received 81 paper submissions from an international community. After a rigorous review process with at least four reviews per paper, 26 papers were finally accepted and presented in the conference. The four best papers from those presented were chosen by the guest editors based on the original reviews and the oral presentations. These papers were significantly extended for this special section and underwent a full journal review process. They cover four different topics in both scientific visualization and information visualization, and present visualization techniques for different data types like flow, multivariate data, textual corpora, and maps.
In “Flow Visualization with Quantified Spatial and Temporal Errors Using Edge Maps,” Harsh Bhatia, Shreeraj Jadhav, Peer-Timo Bremer, Guoning Chen, Joshua A. Levine, Luis Gustavo Nonato, and Valerio Pascucci propose a new data structure called Edge Maps to more precisely represent vector fields defined on triangulated surfaces. The new representation can address two issues facing traditional flow visualizations: inconsistent views of a vector field caused by the numerical errors in computing streamlines through numerical integration, and the wrong perception of certainty by users as the errors are hidden in traditional techniques. Edge Maps encode the inflow/outflow behavior over the boundary of a triangle by mapping entry and exit points of flow paths on the edges of the triangle, and unavoidable spatial and temporal errors are explicitly stored in the representation. They demonstrate that a number of useful flow analysis and visualization tools can be developed based on Edge Maps. This work is one of the two best paper award winners at the conference.
In “Scalable Multivariate Volume Visualization and Analysis Based on Dimension Projection and Parallel Coordinates,” Hanqi Guo, He Xiao, and Xiaoru Yuan present a novel transfer function design interface for volumetric data sets with many independent parameters. An adaptive continuous Parallel Coordinates Plot (PCP) is used to visualize the data distribution on each dimension and possible correlations between neighboring dimensions while Multi-Dimensional Scaling (MDS) plots are used to reveal clusters in low dimensional space. By integrating PCP and MDS and leveraging computing parallelism, the new method enables effective and scalable visualization of large multivariate volume data.
Exploring large textual corpora is becoming a very important topic for the humanities, but also for a wider audience such as researchers. “WORDGRAPH: Keyword-in-Context Visualization for NETSPEAK's Wildcard Search,” by Patrick Riehmann, Henning Gruendl, Martin Potthast, Martin Trenkmann, Benno Stein, and Bernd Froehlich, allows visualizing a queried expression with wildcards as a graph showing all the contexts where the expression template is used. This is a challenge for visualization since the graph has to be readable and the authors use clever techniques to nicely lay out the resulting graph; this is also a challenge for building the graph in interactive time, and again, the authors explain how to preprocess textual corpora to achieve this speed. This work is another best paper award winner at the conference.
In “Visualizing Dynamic Data with Maps,” Daisuke Mashima, Stephen G. Kobourov, and Yifan Hu propose geographic maps as an interesting way to represent relational information. In such maps, entities are represented by countries and links between entities are represented by the corresponding countries sharing borders. The authors exploit geographic maps to visualize dynamics in large data sets. Their challenges are to preserve the viewer's mental map under the dynamics in the data, to ensure readability of each individual layout, and to effectively visualize on the map the changes happening over time. They address those challenges and present a system used to visualize music trends collected from an Internet radio and TV viewing trends from an IPTV service. They suggest that the geographic map metaphor can be an effective tool for a number of visualization needs.
As editors of this special section, we thank Ming Lin, the Editor-in-Chief, for the opportunity to present this work and the staff of TVCG for the outstanding support they have provided. We especially thank the anonymous reviewers for their invaluable contribution in enhancing the quality of the final papers. We look forward to future meetings of Pacific Visualization and encourage our colleagues to consider submitting their work to such meetings.
Giuseppe Di Battista
G. Di Battista is with the Dipartimento di Informatica e Automazione, Universitá Roma Tre, Via della Vasca Navale, 79, 00146, Rome, Italy.
J.-D. Fekete is with INRIA/LRI, Bat 650, Université Paris-Sud, 91405 Orsay, France. E-mail: Jean-Daniel.Fekete@inria.fr.
H. Qu is with the Department of Computer Science and Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong. E-mail: email@example.com.
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Giuseppe Di Battista
received the PhD degree from the University of Rome “La Sapienza” and is currently a faculty member in the Department of Computer Science and Automation at the Third University of Rome. He is a professor of computer science. His current research interests include computer networks, graph drawing, and information visualization. He has published more than 150 papers in the above areas and has given several invited lectures worldwide. He is one of the authors of a book by Prentice Hall on graph drawing. He served and chaired program committees of international symposiums and is editor and guest editor of international journals. He is a founding member of the steering committee for the Graph Drawing Symposium. His research has been founded by the Italian National Research Council, by the EU, and by several industrial sponsors. He has been national and/or local coordinator of many Projects of Relevant Italian National Interest (PRIN). He is a member of the IEEE Computer Society.
received the PhD degree in computer science in 1996 from Université Paris-Sud. He joined INRIA in 2002 as a confirmed researcher and became research director in 2006. He is the scientific leader of the INRIA Project Team AVIZ that he founded in 2007. His main research areas are visual analytics, information visualization, and human computer interaction. He is the President of the French-Speaking HCI Association (AFIHM), and associate editor of the IEEE Transactions on Visualization and Computer Graphics
). He served as conference chair of the IEEE InfoVis Conference and paper cochair of the IEEE Pacific Visualization Conference. He is a member of the ACM and of the IEEE Computer Society.
received the BS degree in mathematics from Xi'an Jiaotong University, China, and the MS and PhD (2004) degrees in computer science from Stony Brook University. He is an associate professor in the Department of Computer Science and Engineering at the Hong Kong University of Science and Technology. His main research interests are in visualization and computer graphics. He is on the steering committee of the IEEE Pacific Visualization Conferences, and serves as the program cochair for IEEE PacificVis 2011 and 2012 and the conference cochair for VINCI 2011 and VINCI 2012. He received an Honorable Mention for the Best Paper Award at IEEE Visualization 2009 and is a winner of the 2009 IBM Faculty Award. He is a member of the IEEE Computer Society.