Publications
A Parallel Visualization Pipeline for Terascale Earthquake Simulations (DVD Proceedings)
Hongfeng Yu, Kwan-Liu Ma, and Joel WellingIn Proceedings of ACM/IEEE Conference on Supercomputing
November, 2004This paper presents a parallel visualization pipeline implemented at the Pittsburgh Supercomputing Center (PSC) for studying the largest earthquake simulation ever performed. The simulation employs 100 million hexahedral cells to model 3D seismic wave propagation of the 1994 Northridge earthquake. The time-varying dataset produced by the simulation requires terabytes of storage space. Our solution for visualizing such terascale simulations is based on a parallel adaptive rendering algorithm coupled with a new parallel I/O strategy which effectively reduces interframe delay by dedicating some processors to I/O and preprocessing tasks ...
Visualization for Security
Kwan-Liu MaVisFiles, Computer Graphics
ACM SIGGRAPH
Volume 38, Number 4, November, 2004, pp. 4-6The widespread use of computers and internet makes computer security an increasingly important problem. Homeland security has also become the top prority of our nation. One basic approach to the security problem is to analyze large data collected from all possible sources. The results of the analysis can help spot suspecious activities and track down known malicious intents. As demonstrated in many other data analysis problems, visualization can be very useful when massive data is involved. ...
Anisotropic Volume Rendering for Extremely Dense, Thin Line Data
Greg Schussman and Kwan-Liu MaIn Proceedings of IEEE Visualization 2004 Conference
October, 2004, pp. 107-114Many large scale physics-based simulations which take place on PC clusters or supercomputers produce huge amounts of data including vector fields. While these vector data such as electromagnetic fields, fluid flow fields, or particle paths can be represented by lines, the sheer number of the lines overwhelms the memory and computation capability of a high-end PC used for visualization. Further, very dense or intertwined lines, rendered with traditional visualization techniques, can produce unintelligible results with unclear depth relationships between the lines and no sense of global structure ...
Visualizing Gyrokinetic Simulations
David Crawford, Kwan-Liu Ma, Min-Yu Huang, Scott Klasky, and Stephanie EthierIn Proceedings of IEEE Visualization 2004 Conference
October, 2004, pp. 59-66The continuing advancement of plasma science is central to realizing fusion as an inexpensive and safe energy source. Gryokinetic simulations of plasmas are fundamental to the understanding of turbulent transport in fusion plasma. This paper discusses the visualization challenges presented by gyrokinetic simulations using magnetic field line following coordinates, and presents an effective solution exploiting programmable graphics hardware to enable interactive volume visualization of 3D plasma flow on a toroidal coordinate system ...
Combining Visual and Automated Data Mining for Near-Real-Time Anomaly Detection and Analysis in BGP
Soon Tee Teoh, Ke Zhang, Shih-Ming Tseng, Kwan-Liu Ma, and S. Felix WuIn Proceedings of ACM CCS Workshop on Visualization and Data Mining for Computer Security, ACM Conference on Computer and Communications Security
October, 2004, pp. 35-44The security of Internet routing is a major concern because attacks and errors can result in data packets not reaching their intended destination and/or falling into the wrong hands. A key step in improving routing security is to analyze and understand it. In the past, we and other researchers have presented various visual-based, statistical-based, and signature-based methods of analyzing Internet routing data ...
PortVis: A Tool for Port-Based Detection of Security Events
Jonathan McPherson, Kwan-Liu Ma, Paul Krystosek, Tony Bartoletti, and Marvin ChristensenIn Proceedings of ACM CCS Workshop on Visualization and Data Mining for Computer Security, ACM Conference on Computer and Communications Security
October, 2004, pp. 73-81Most visualizations of security-related network data require large amounts of finely detailed, high-dimensional data. However, in some cases, the data available can only be coarsely detailed because of security concerns or other limitations. How can interesting security events still be discovered in data that lacks important details, such as IP addresses, network security alarms, and labels? In this paper, we discuss a system we have designed that takes very coarsely detailed data—basic, summarized information of the activity on each TCP port during each given hour—and uses ...
Lighting Transfer Functions Using Gradient Aligned Sampling
Eric Lum and Kwan-Liu MaIn Proceedings of IEEE Visualization 2004 Conference
October, 2004, pp. 289-296An important task in volume rendering is the visualization of boundaries between materials. This is typically accomplished using transfer functions that increase opacity based on a voxel’s value and gradient. Lighting also plays a crucial role in illustrating surfaces. In this paper we present a multi-dimensional transfer function method for enhancing surfaces, not through the variation of opacity, but through the modification of surface shading ...
Visual Data Analysis for Detecting Flaws and Intruders in Computer Network Systems
Soon Tee Teoh, T.J. Jankun-Kelly, Kwan-Liu Ma, and Felix WuIEEE Computer Graphics and Applications (Special Issue on Visual Analytics)
Volume 24, Number 5, September/October, 2004, pp. 27-35Keeping computer and network systems secure and stable requires collecting vast amounts of data and analyzing how the systems perform dynamically. No matter how rigorous a system’s design process, runtime factors can compromise performance. Even network protocols with strong theoretical bases can suffer security flaws and instability when deployed. Furthermore, few systems are designed with perfect security. Intrusion detection and response are thus important components of any computer system. ...
Techniques for Visualizing Time-Varying Volume Data
Kwan-Liu Ma and Eric LumVisualization Handbook
Chapter 26 pp. 511-531October, 2004Our ability to study and understand complex, transient phenomena is critical to the solution of many scientific and engineering problems. Examples include data from the study of neuron excitement, crack propagation in a material, evolution of a thunderstorm, unsteady flow surrounding an aircraft, seismic reflection from geological strata, and the merging of galaxies. A typical time-varying dataset from a computational fluid dynamics ...
Visualization for Computational Accelerator Physics
Kwan-Liu Ma, Greg Schussman, and Brett WilsonVisualization Handbook
Chapter 47 pp. 152-154October, 2004High-energy physics is about the study of the smallest elementary particles, the building blocks of the universe. New discoveries in high-energy physics often lead to fundamental advances in other disciplines such as astronomy, biology, environmental science, materials science, and medicine. Particle accelerators are used in the laboratory by high-energy physicists to study the properties of these particles, how they are created, and how they interact . ...
Data Visualization
Kwan-Liu MaBerkshire Encyclopedia of Human-Computer Interaction
pp.152-154Berkshire Publishing Group, October, 2004Data visualization has emerged as a new discipline that is about the art and science of using computers to make pictures that elucidate a concept, phenomenon, relationship, or trend hidden in a large quantity of data. By extensively using interactive 3D graphics it is beyond the making of static illustrations or graphs. A strong emphasis of data visualization is thus placed on interactive exploration. ...
I/O Strategies for Parallel Rendering of Large Time-Varying Volume Data
Hongfeng Yu, Kwan-Liu Ma, and Joel WellingIn Proceedings of the Eurographics/ACM SIGGRAPH Symposium on Parallel Graphics and Visualization
June, 2004, pp. 31-40This paper presents I/O solutions for the visualization of time-varying volume data in a parallel and distributed computing environment. Depending on the number of rendering processors used, our I/O strategies help significantly lower interframe delay by employing a set of I/O processors coupled with MPI parallel I/O support. The targeted application is earthquake modeling using a large 3D unstructured mesh consisting of one hundred millions cells ...
Rendering Complexity in Computer-Generted Pen-and-Ink Illustrations
Brett Wilson and Kwan-Liu MaIn Proceedings of the International Symposium on NonPhotorealistic Animation and Rendering (NPAR 2004)
June, 2004, pp. 129-137We present a method to aid in the generation of pen-and-ink style renderings of complex geometry. Most illustration algorithms focus on rendering a small number of surfaces with as much detail and expression as possible. These methods break down when the scene is composed of many small, overlapping details that are not individually resolvable. We propose a hybrid 2D/3D pipeline that incorporates image processing with the full scene geometry to extract regions which may require special handling ...
A Cluster-Space Visual Interface for Arbitrary Dimensional Classification of Volume Data
Fan-Yin Tzeng and Kwan-Liu MaIn Proceedings of Joint Eurographics-IEEE TVCG Symposium on Visualization
May, 2004, pp. 17-24In volume visualization, users typically specify transfer functions to classify the data and assign visual attributes to each material class. Higher-dimensional classication makes it easier to differentiate material classes since more data properties are considered. One of the difculties in using higher-dimensional classication is the absence of appropriate user interfaces. We introduce an intuitive user interface that allows the user to work in the cluster space, which shows the material classes with a set of material widgets, rather than work in the transfer function
space ...
High-Quality Lighting and Efficient Pre-Integration for Volume Rendering
Eric Lum, Brett Wilson, and Kwan-Liu MaIn Proceedings of Joint Eurographics-IEEE TVCG Symposium on Visualization
May, 2004, pp. 25-34Pre-integrated volume rendering is an effective technique for generating high-quality visualizations. The precomputed lookup tables used by this method are slow to compute and can not include truly pre-integrated lighting due to space constraints. The lighting for pre-integrated rendering is therefore subject to the same sampling artifacts as in standard volume rendering. We propose methods to speed up lookup table generation and minimize lighting artifacts ...