Exhibit: Research-related Images
Jim X. Chen, Ph.D.
Micromap: Web-based Micromap Plot for Statistical Georgraphical Data
by Jim X. Chen, Daniel B. Carr, Xusheng Wang
George Mason University
Fairfax, VA 22030-4444
B. Sue Bell and Linda W. Pickle
National Cancer Institute
Bethesda, MD 20892-8317
Linked Micromap plots (LM plots) present a template for the display of spatially indexed statistical summaries. This template has four key features . First, LM plots include at least three parallel sequences of panels (micromap, lable, and statistical summary) that are linked by position. The second feature is sorting the units of study. The third feature partitions the study units into panels to focus attention on a few units at a time. The forth feature links the highlighted study units across corresponding panels of the sequences. LM plots represent a new visualization methodology that is useful in the data and knowledge based pattern representation and knowledge discovery process. It can be used to visualize various complex data in many areas [1, 2]. Interactive LM plots can let readers clearly view and compare various relationships among the study units.
Using LM plots to display the federal cancer statistical summaries is an effective application. In this article, we nonetheless describe a web-based LM plots application that is developed for the National Cancer Institute (NCI) to visualize the cancer statistical summaries of the United States and all the states on the Internet. These web-based LM plots not only present all the key features of LM plots, but alsoshow the higher interactivity. Moreover, the magnified micromap and the overall look of statistical summaries make snternet SSince web is a public information, inventory, atusing LM plots on the web will make more readers share this effective visualization methodology, and bring this methodology to a more practical environment.
Anatomy: Virtual Human Anatomy
by Jim X. Chen, Yanling Liu, and Lin Yang
To learn human anatomy, medical students must practice on cadavers, as must physicians when they want to brush up on their anatomy knowledge. However, cadavers are in short supply in medical schools worldwide. Virtual anatomy and surgery can potentially solve this problem. We present a system VHASS (Virtual Human Anatomy and Surgery System) based on reconstructing the human body using cryosection images. By constructing 3D models that include details of human organs, we can give medical students and physicians unlimited access to realistic virtual cadavers.
Currently, many systems can reconstruct the human body via magnetic resonance imaging (MRI) or computerized tomography (CT). However, these systems have a common drawback in that they can’t group human body components and display human tissues in their natural colors. Consequently, technicians have difficulty in identifying human body components clearly and must assign artificial colors when generating 3D models from these images, which might look good, but are unrealistic and hinder anatomy and surgery simulation and training. Our virtual surgery system VHASS provides a better platform for virtual anatomy because it dissects all human organs according to their anatomic structures, separates human tissues within cryosection images, reconstructs a 3D mesh surface for each part, and, finally, renders each part as a high-quality 3D model, generating all parts and tissues with their natural colors.
L. Yang, J.X. Chen, and Y. Liu, “Virtual Human Anatomy,” IEEE Computing in Science and Engineering, vol. 7, no.5, Sept. 2005, pp. 71-73.
Dust: Real-time Simulation of Dust Behavior
by Jim X. Chen, Jingfang Wang, Xiaodong Fu, and Edward J. Wegman
(Funded by Office of the Provost at GMU; PI: Jim X. Chen)
Simulation of physically realistic complex dust behavior is very useful in training, education, art, advertising, and entertainment. There are no published models for real-time simulation of dust behavior generated by a traveling vehicle. We use particle systems, computational fluid dynamics, and behavioral simulation techniques to simulate dust behavior in real time. First, we analyze the forces and factors that affect dust generation and the behavior after dust particles are generated. Then, we construct physically-based empirical models to generate dust particles and control the behavior accordingly. We further simplify the numerical calculations by dividing dust behavior into three stages, and establishing simplified particle system models for each stage. We employ motion blur, particle blending, texture mapping, and other computer graphics techniques to achieve the final results. Our contributions include constructing physically-based empirical models to generate dust behavior and achieving simulation of the behavior in real time.
J. X. Chen, X. Fu, and E. J. Wegman, "Real-Time Simulation of Dust Behaviors Generated by a Fast Traveling Vehicle," ACM Transactions on Modeling and Computer Simulation, Vol. 9, No. 2, April, 1999, pp. 81-104.
Knee: Virtual Surgery: Knee Surgery Assistanceby Jim X. Chen and Ying Zhu
(Funded by Knee Alignment of Greater Washington, PI: Jim X. Chen)
We use computer graphics, physics-based modeling, and interactive visualization to assist the knee surgery study and operation. Current static examinations of the knee such as X-rays and MRI's are replaced by interactive visualization, surgery study, planning, exercise, and results predictions. First, a set of magnetic resonant image (MRI) slices of the knee, the height and weight of the patient, and other input data will be collected from the patient. Then, a 3D knee surface model will be constructed from the MRI slices and a standard reference knee model. After that, animations of the gait cycles will be generated with interactive visualization of the pressure distributions at the knee joint, which are calculated according to the current posture. At the same time, a virtual surgery can be performed, data concerning the surgery process can be recorded, and the simulation and visualization can demonstrate the gait cycles and the modified pressure distributions right after the surgery.
J.X. Chen, H. Wechsler, J.M. Pullen, Y. Zhu, E.B. MacMahon, “Knee Surgery Assistance: Patient Model Construction, Motion Simulation, and Biomechanical Visualization,” IEEE Transactions on Biomedical Engineering, vol. 48, no. 9, Sept. 2001, pp. 1042-1052.
Liquid: Real-time Simulation of Fluid Behaviorby Jim X. Chen
(Funded by US Army STRICOM)
We present a new method for real-time fluid simulation in computer graphics and dynamic virtual environments. By solving the 2D Navier-Stokes equations using a computational fluid dynamics method, we map the surface into 3D using the corresponding pressures in the fluid flow field. This achieves realistic real-time fluid surface behaviors by employing the physical governing laws of fluids but avoiding extensive 3D fluid dynamics computations. To complement the surface behaviors, we calculate fluid volume and external boundary changes separately to achieve full 3D general fluid flow. Unlike previous computer graphics fluid models, our model allows multiple fluid sources to be placed interactively at arbitrary locations in a dynamic virtual environment. The fluid will flow from these sources at user modifiable flow rates following a terrain which can be dynamically modified, for example, by a bulldozer. Our approach can simulate many different fluid behaviors by changing the internal or external boundary conditions. It can model different kinds of fluids by varying the Reynolds number. It can simulate objects moving or floating in fluids. It can produce synchronized general fluid flow in a distributed interactive simulation.
J. X. Chen, N. V. Lobo, C. E. Hughes and J. M. Moshell, "Real-time Fluid Simulation in a Networked Virtual Environment," IEEE Computer Graphics and Applications, Vol. 17, No. 3, 1997, pp. 52-61.
J. X. Chen and N. V. Lobo, "Toward Interactive-Rate Simulation of Fluids with Moving Obstacles Using Navier-Stokes Equations," CVGIP: Graphical Models and Image Processing, Vol. 57, No. 2, 1995, pp. 107-116.
DEVISE: Designing Environments for Virtual Immersive Science Educationby Mike Behrmann, Jim X. Chen, Chris Dede, Debra Sprague, Xusheng Wang, and Shuangbao Wang
(Funded by US Department of Education; PI Mike Behrmann; Co-PI Jim X. Chen, Chris Dede)Students with learning disabilities continue to fall behind regular education students as they move into more cognitively competing areas, such as science and math instruction. Immersive virtual environments can increase access for students in regular physics education curriculum, by providing 3D abstractions, for those concepts that cannot be represented in alternative delivery formats. The adaptability and creation of new virtual tools have the potential to provide students with learning disabilities access to the regular science curriculum. This project builds immersive multi-sensory virtual learning environments that address foundations of physics instruction for students with learning disabilities.
MUVE (Multi-User Virtual Environment): Museum-Related Multimedia and Virtual Environments for Teaching and Learning Scienceby Chris Dede, Jim X. Chen, Kevin Ruess, Yonggao Yang, Xusheng Wang et al.
(Funded by NSF; PI: Chris Dede; Co-PI: Jim X. Chen, L. Fontana, D. Allison.)This research project is creating and evaluating multi-user virtual environments (MUVEs) that use digitized museum resources to enhance middle school students' motivation and learning about science and its impacts on society. MUVEs enable multiple simultaneous participants to access virtual architectures configured for learning, to interact with digital artifacts, to represent themselves through graphical "avatars," to communicate both with other participants and with computer-based agents, and to enact collaborative activities of various types. The project's educational environments are extending current MUVE capabilities in order to study the science learning potential of interactive virtual museum exhibits and participatory historical situations in science units using the NSF-funded Multimedia and Thinking Skills (MMTS) program, an inquiry-centered curriculum engine. George Mason University's (GMU) Computer Graphics and Virtual Reality Labs, the Division of Information Technology and Society in the Smithsonian's National Museum of American History (NMAH), and pilot teachers from the Gunston Middle School in Arlington, Virginia are co-designing these MUVEs and implementing them in a variety of middle school settings. In particular, this project is studying how the design characteristics of these learning experiences affect students' motivation and educational outcomes, as well as the extent to which digitized museum can aid pupils' performance on assessments related to national science standards. This research also is examining both the process needed to successfully implement MMTS-based MUVEs in typical classroom settings and ways to enable strong learning outcomes across a wide range of individual student characteristics.
ScienceSpace: Virtual Reality for Learning Abstract Scientific Conceptsby Bowen Loftin, Chris Dede, Jim X. Chen, Xusheng Wang, et al.
(Funded by NSF)The purpose of Project ScienceSpace is to explore the strengths and limits of virtual reality (sensory immersion, 3-D representation) as a medium for science education. This project is a joint research venture among George Mason University, the University of Houston, and NASA's Johnson Space Center. Dr. Chris Dede from Harvard University is the project Co-Principal Investigator and Dr. R. Bowen Loftin of the University of Houston is the Principal investigator. Dr. Jim Chen and Mr Xusheng Wang have been funded on the project and are responsible for developing several major components for this project.