Publications
Transform Coding for Hardware-Accelerated Volume Rendering
Nathan Fout and Kwan-Liu MaIEEE Transactions on Visualization and Computer Graphics
(Also Proceedings of the Visualization 2007 Conference)
Volume 13, Number 6, November, 2007Hardware-accelerated volume rendering using the GPU is now the standard approach for real-time volume rendering, although limited graphics memory can present a problem when rendering large volume data sets. Volumetric compression in which the decompression is coupled to rendering has been shown to be an effective solution to this problem; however, most existing techniques were developed in the context of software volume rendering, and all but the simplest approaches are prohibitive in a real-time hardware-accelerated volume rendering context ...
Parallel Hierarchical Visualization of Large 3D Time-Varying Vector Fields
Hongfeng Yu, Chaoli Wang, and Kwan-Liu MaProceedings of the Supercomputing 2007 Conference (SC '07)
November, 2007We present the design of a scalable parallel pathline construction method for visualizing large time-varying 3D vector fields. A 4D (i.e., time and the 3D spatial domain) representation of the vector field is introduced to make a time accurate depiction of the flow field. This representation also allows us to obtain pathlines through streamline tracing in the 4D space. Furthermore, a hierarchical representation of the 4D vector field, constructed by clustering the 4D field, makes possible interactive visualization of the flow field at different levels of abstraction ...
Emerging Visualization Technologies for Ultra-Scale Simulations
Kwan-Liu MaCTWatch Quarterly
Volume 3, Number 4, November, 2007Supercomputers give scientists the power to model highly complex and detailed physical phenomena and chemical processes, leading to many advances in science and engineering. With the current growth rates of supercomputing speed and capacity, scientists are anticipated to study many problems of unprecedented complexity and fidelity and attempt to study many new problems for the first time. The size and complexity of the data produced by such ultra-scale simulations, however, present tremendous challenges to the subsequent data visualization and analysis tasks, creating a growing gap between scientists’ ability to simulate complex physics at high resolution and their ability to extract knowledge from the resulting massive data sets ...
Analysis of BGP Origin AS Changes among Brazil-Related Autonomous Systems
Shih-Ming Tseng, Ke Zhang, Felix Wu, Kwan-Liu Ma, Soon Tee Teoh, and Xiaoliang ZhaoIn Proceedings of Proceedings of the 7th IEEE International Workshop on IP Operations and Management (IPOM 2007)
Springer Verlag, October, 2007On the inter-domain Internet today, the address prefix origin in our BGP operations has become a major security concern. This critical problem can be stated simply as “Is the originating Autonomous
System (AS) authorized to advertise the destination address prefix?” In the long term maybe we will be able to prevent this problem by applying proposed solutions such as SBGP[1] or SoBGP[2] ...
VICA: A Voronoi Interface for Visualizing Collaborative Annotations
Yue Wang, James Shearer, and Kwan-Liu MaIn Proceedings of the 4th International Conference on Cooperative Design, Visualization, and Engineering
Springer-Verlag, September, 2007Large-scale scientific investigation often includes collaborative data exploration among geographically distributed researchers. The tools used for this exploration typically include some communicative component, and this component often forms the basis for insight and idea sharing among collaborators. Minimizing the tool interaction required to locate “interesting” communications is therefore of paramount importance. We present the design of a novel visualization interface for representing the communications among multiple collaborating authors, and detail the benefits of our approach versus traditional methods ...
Automatic Feature Modeling Techniques for Volume Segmentation Applications
Runzhen Huang, Hongfeng Yu, Kwan-Liu Ma, and Oliver StaadtProceedings of Volume Graphics 2007
September, 2007In many volume segmentation and visualization tasks, the ability to correctly identify the boundary surface of each volumetric feature of interest in the data is desirable. This surface can be used in subsequent quantitative study of the segmented features. In this paper, we present an automatic approach to generate accurate representations of a feature of interest from volume segmentation. Our method first locates a set of points which tightly define the boundary of the volumetric feature ...
Machine Learning to Boost the Next Generation of Visualization Technology
Kwan-Liu MaIEEE Computer Graphics and Applications
Volume 27, Number 5, September/October, 2007, pp. 6-9Many visualization systems do not get widespread adoption because they confront the user with sophisticated operations and interfaces. The author suggests augmenting visualization systems with learning capability to improve both the performance and usability of visualization systems. Several examples including volume segmentation, flow feature extraction, and network security are given illustrating how machine learning can help streamline the process of visualization, simplify the user interface and interaction, and support collaborative work ...
3D Paper-Cut Modeling and Animation
Yan Li, Jinhui Yu, Kwan-Liu Ma, and Jiaoying ShiThe Journal of Computer Animation and Virtual Worlds
(Also Proceedings of CASA 2007, June 11-13)
Volume 18, 2007Paper-cut is one of the most characteristic Chinese folk arts, often used during festivals and celebrations. Chinese artists have used paper-cut to make animations. Typical paper-cut artwork is made with 2D illustrations on paper, and making many frames necessary for an entire animation can be tedious and expensive. We present a system that allows a designer to directly annotate a 3D model with paper-cut patterns, while still allowing for adding an artistic touch to the design ...
Visual Interrogation of Gyrokinetic Particle Simulations
Chad Johnes, Kwan-Liu Ma, Allen Sanderson, and Lee Roy Myers JrJournal of Physics
(Proceedings of SciDAC 2007 Conference)
Volume 78, June, 2007Gyrokinetic particle simulations are critical to the study of anomalous energy transport associated with plasma microturbulence in magnetic confinement fusion experiments. The simulations are conducted on massively parallel computers and produce large quantities of particles, variables, and time steps, thus presenting a formidable challenge to data analysis tasks. We present two new visualization techniques for scientists to improve their understanding of the time-varying, multivariate particle data. ...
In Situ Processing and Visualization for Ultrascale Simulations
Kwan-Liu Ma, Chaoli Wang, Hongfeng Yu, and Anna TikhonovaJournal of Physics
(Proceedings of SciDAC 2007 Conference)
Volume 78, June, 2007The growing power of parallel supercomputers gives scientists the ability to simulate more complex problems at higher fidelity, leading to many high-impact scientific advances. To maximize the utilization of the vast amount of data generated by these simulations, scientists also need scalable solutions for studying their data to different extents and at different abstraction levels. As we move into peta- and exa-scale computing, simply dumping as much raw simulation data as the storage capacity allows for post-processing analysis and visualization is no longer a viable approach ...
Ultra-Scale Visualization: Research and Education
Kwan-Liu Ma, Robert Ross, Jian Huang, Greg Humphreys, Nelson Max, Kenneth Moreland, John D. Owens, and Han-Wei ShenJournal of Physics
(Proceedings of SciDAC 2007 Conference)
Volume 78, June, 2007Understanding the science behind large-scale simulations and high-throughput experiments requires extracting meaning from data sets of hundreds of terabytes or more. Visualization is the most intuitive means for scientists to understand data at this scale, and the most effective way to communicate their findings with others. Even though visualization technology has matured over the past twenty years, it is still limited by the extent and scale of the data that it can be applied to, and also by the functionalities that were mostly designed for single-user, single-variable, and single-space investigation ...
Path Visualization for Adjacency Matrices
Zeqian Shen and Kwan-Liu MaIn Proceedings of Eurographics/IEEE VGTC Syposium on Visualization
May, 2007, pp. 83-90For 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. ...
A Tri-Space Visualization Interface for Analyzing Time-Varying Multivariate Volume Data
Hiroshi Akiba and Kwan-Liu MaIn Proceedings of Eurographics/IEEE VGTC Symposium on Visualization
May, 2007, pp. 115-122The 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 must explore in the temporal, spatial, and variable domains of the data, which is not easily performed with a conventional visualization tool. This paper presents a new visualization interface (UI) addressing this problem ...
A Model and Framework for Visualization Exploration
T.J. Jankun-Kelly, Kwan-Liu Ma, and Michael GertzIEEE Transactions for Visualization and Computer Graphics
Volume 13, Number 2, March, 2007, pp. 357-369Visualization exploration is the process of extracting insight from data via interaction with visual depictions of that data. Visualization exploration is more than presentation; the interaction with both the data and its depiction is as important as the data and depiction itself. Significant visualization research has focused on the generation of visualizations (the depiction); less effort has focused on the exploratory aspects of visualization (the process) ...
Visualizing Multivariate Volume Data from Turbulent Combustion Simulations
Hiroshi Akiba, Kwan-Liu Ma, Jacqueline H. Chen, and Evatt R. HawkesIEEE Computing in Science and Engineering
March/April, 2007, pp. 86-93To understand dynamic mechanisms, scientists need intuitive and convenient ways to validate known relationships and reveal hidden ones among multiple variables ...
Multi-Scale Morphological Volume Segmentation and Visualization
Runzhen Huang, Eric Lum, and Kwan-Liu MaIn Proceedings of Asia-Pacific Symposium on Visualization
February, 2007, pp. 121-128This paper presents a multi-scale morphology approach to the volume segmentation and visualization problem. The basis of the approach is applying morphological operations with spherical structuring elements at various sizes to create a representation of the volume data that encodes structural information at multiple scales. Through an interactive user interface, the user can effectively segment and visualize a specific feature of interest using ...
Visualizing Social Interaction in Open Source Software Projects
Michael Ogawa, Kwan-Liu Ma, Christian Bird, Premkumar Devanbu, and Alex GourleyIn Proceedings of Asia-Pacific Symposium on Visualization
February, 2007, pp. 25-32Open source software projects such as Apache and Mozilla present an opportunity for information visualization. Since these projects typically require collaboration between developers located far apart, the amount of electronic communication between them is large. Our goal is to apply information visualization techniques to assist software engineering scientists and project managers with analyzing the data. We present a visualization technique that provides an intuitive, time-series, interactive summary view of the the social groups that form, evolve and vanish during the entire lifetime of the project ...
Visualization of Sanitized Email Logs for Spam Analysis
Chris Muelder and Kwan-Liu MaIn Proceedings of Asia-Pacific Symposium on Visualization
February, 2007, pp. 9-16Email has become an integral method of communication. However, it is still plagued by vast amounts of spam. Many statistical techniques, such as Bayesian filtering, have been applied to this problem, and been proven useful. But these techniques in general require training. Another common method of spam prevention is blacklisting known spam sources. In order to do this, the sources must be identified ...