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Chuan-Kai Yang (楊傳凱)

 
Professor 

Department of Information Management
National Taiwan University of Science and Technology

 

ckyang@cs.ntust.edu.tw
www.cs.ntust.edu.tw/ckyang
Tel : (02) 2737-6756
Fax: (02) 27373-6777


 
 

 

Education

Ph.d., Computer Science, 
State University of New York, 
Dissertation Topic: "On-the-Fly Processing of Compressed Volume Data" 
Advisor: Professor Tzi-cker Chiueh 

Master, Computer Science,
National Taiwan University, Taiwan, May 1993, 
Thesis Topic: "The synthesis of a cavern with eroded stalactites and stalagmites using radiosity illumination" 
Advisor: Professor Ming Ouhyoung 

Bachelor, Mathematics,
National Taiwan, University, Taiwan, May 1991

Research
Interests

My research interests are mainly focused on the fields of Volume Visualization, Computer Graphics and Multimedia Systems. 

  • Volume Visualization: volume visualization and its acceleration techniques, including out-of-core rendering, I/O conscious rendering, application-specific prefetching, and integration with volume compression and volume simplification; iso-surface extraction 
  • Computer Graphics: radiosity rendering, photo realistic rendering, natural phenomenon modeling, physics-based modeling 
  • Multimedia Systems: video authoring, video annotations, graphical user interfaces 

Research 
Summary

  • Volume Visualization

My Ph.D. research here at Stony Brook involves mainly on volume visualization. And the goal is to address the two general problems in volume rendering: huge data sets and lengthy rendering process. The first one burdens the storage system as well as the run-time memory requirement while the second one hinders the interactivity thus making most rendering systems far from attractive or even practically useless. To address the first problem, compression is an obvious choice. However, the naive use of decompression then rendering only solves the storage issue while a more clever integration of both may help reducing the rendering time as well. 

This project attempted to solve both problems in one shot by making use of the FPST (Fourier Projection Slice Theorem), which can provide an asymptotically faster algorithm for volume rendering. By partitioning the data sets into sub-cubes and compositing the sub-images from applying the FPST on each of them, our system can perform rendering directly in the compression domain, thus saving data loading time, reducing memory footprint, and at the same time being asymptotically faster. 

For irregular grids, where the structure of data sets is quite complex and apparently the previous method cannot be applied, we therefore used a different strategy called on-the-fly rendering during decompression. The system, called Gatun, not only loads a data set from its compressed form, thus saving the data loading time, but also performs a garbage collection scheme to further minimize the working set of the renderer, thus further improving the rendering speed as a result. Both compression and rendering algorithms in Gatun exploit the same local connectivity information among adjacent tetrahedra, and thus can be tightly integrated into a unified implementation framework. 

In this project, we further incorporate volume simplification into Gatun. Since simplification is a form of lossy compression, the on-the-fly volume simplification algorithm provides a powerful mechanism to dynamically create versions of a tetrahedral mesh at multiple resolution levels directly from its losslessly compressed representation. With decompression, simplification and rendering all merged together, Gatun becomes a seamless and powerful pipeline for volume visualization.

There is another way to address the first issue of data loading time, at least for regular grids: by prefetching. Because our rendering algorithm is raycasting, where the data accessing patterns are quite irregular, normal Unix linear prefetching is proven not very useful. We have implemented two systems to mask I/O time by performing prefetching, one is done manually, while the other is done automatically. 

This work re-examines implementation strategies of the ray casting algorithm, taking into account both computation and I/O overheads. Specifically, we developed a data-driven execution model for ray casting that achieves the maximum overlap between rendering computation and disk I/O. It can also be readily extended to do out-of-core visualization as well. 

The main idea of our approach is to convert an application into two threads: a computation thread , which is the original program containing both computation and disk I/O, and a prefetch thread , which contains all the instructions in the original program that are related to disk I/O. At run time, the prefetch thread runs far ahead of the computation thread, so that blocks can be prefetched and put in the file system buffer cache before the computation thread needs them. A source-to-source translator is developed to automatically generate the prefetch and computation thread from a given application program, without any user intervention. 

  • Computer Graphics

My master thesis in National Taiwan University involved mainly three techniques: 

    • Fractal modeling, Recursive Subdivisions

We applied this technique to model stalactites, whose shapes are usually much sharper and simpler. Using fractal theory to employ randomly and adaptively recursive subdivision at each level, a good approximation can be achieved. 

    • Natural Phenomenon Modeling

Stalagmites are more difficult to model because of their much higher complexity. Therefore instead of using fractal subdivision, we simulate the natural process of erosion and accumulation, the reasons how they have been formed, to obtain a better approximation. 

    • Radiosity Illumination

The global illumination method radiosity (by progressive refinement) is used to provide a more photorealistic lighting environment for the synthesized cavern with stalactites and stalagmites.

  • Multimedia Systems

I have also been involved in the following project where I have designed most of the graphical user interfaces. To have a more efficient display and better control of the video components required from the project, I have traced and modified the well known Berkeley Mpeg Player (for video display) and XV (for colormap tuning) thus gaining substantial amount of knowledge of the X windows under the Unix environment. In this project, I have also implemented the video annotation part, whose enabling technique is the underlying object tracking in video mechanism that combines the algorithms of active contour (snake) and motion estimation


This system, called Zodiac provides users a conceptually clean and semantically powerful branching history model of edit operations to organize the authoring process, and to navigate among the design alternatives. In addition, by analyzing the edit history, Zodiac is able to reliably detect a composed stream's shot and scene boundaries, which facilitate interactive video browsing. It also features a video object annotation capability that allows users to associate annotations to moving objects in a video sequence. The annotations themselves could be text, image, audio, or video. Zodiac is built on top of MMFS (MultiMedia File System), a file system specifically designed for interactive multimedia development environments, and implements an internal buffer manager that supports transparent lossless compression/decompression. 

Experience

  • Assistant Professor (2002/08-2008/02), Department of Information Management, National Taiwan University of Science and Technology

  • Research Assistant (1991-1993), National Taiwan University: 

Built a generic graphics rendering system, which incorporates 3D transformations, clippings, different lighting and shadings. Designed a modeling system which combined fractal theory for subdivision and a natural simulation of erosion and accumulation effect for a cavern with stalactites and stalagmites. Studied and implemented the radiosity rendering method. 

  • System Maintainer and Software Developer (1993-1995), Navel Headquarters, Taiwan, in compulsory military service: 

Performed system maintenance for hundreds of machines, including both software and hardware setup and troubleshooting. Designed a large-scale documentary and personnel system using Gupta's SQLwindows. The system included detailed interface design and full-blown database functionalities. 

  • Summer Intern in 1996, ICASE/NASA LaRC

Studied the generic wavelet theory and how it is used to perform multiresolution analysis for arbitrary surface mesh type. Also implemented a generic 3D volume compressor that can support different wavelet transforms. 

  • Teaching Assistant (1996-1997), State University of New York at Stony Brook: 

For courses of "C & Unix" and "Computer Graphics". 

  • Research Assistant (1997-Present), State University of New York at Stony Brook: 

Involved in multiple projects. See "Research Summary".

Journal 
Publications

(15) Chuan-Kai Yang and Ching-Yang Tsai, “Fast Architecture Prototyping through 3D Collage”, to appear in Multimedia Tools and Applications. (SCI) (NSC-98-2221-E-011-099-MY2)
(14) Jia-Kai Chou, Chuan-Kai Yang and Sing-Dong Gong, “Face-off: Automatic Alteration of Facial Features”, to appear in Multimedia Tools and Applications. (SCI) (NSC-98-2221-E-011-099-MY2)
(13) Chuan-kai Yang, “An Optimal Balanced Partitioning of a Set of 1D Intervals”, International Journal of Artificial Life Research 1(2): 72-79, 2010. (NSC-98-2221-E-011-099-MY2)
(12) Hsing-Chin Chang,
Chuan-kai Yang, Jia-Wei Chiou and Shih-Hsien Liu, “Synthesizing Solid Particle Textures via a Visual-Hull Algorithm”, Computers and Graphics 33(5):648-658, 2009. (SCI) (NSC-97-2221-E-011-109-)
(11)
Chuan-kai Yang and Chiang-Han Hong, “A New Seed-Set Finding Approach for Iso-Surface Extraction”, Journal of Information Science and Engineering 24(6):1771-1785, 2008. (SCI) (NSC-96-2221-E-011-139-)
(10)
Chuan-kai Yang and Li-kai Peng, “Automatic Mood-Transferring between Color Images”, IEEE Computer Graphics and Applications 28(2):52-61, 2008. (SCI) (NSC-96-2221-E-011-139-)
(9) Chuan-kai Yang and Wei-ting Chiang, “An Interactive Facial Expression Generation System”, Multimedia Tools and Applications 40(1):41-60, 2008. (SCI) (NSC-96-2221-E-011-139-)
(8) Chuan-kai Yang and Hui-lin Yang, “Realization of Seurat’s Pointillism via Non-Photorealistic Rendering”, The Visual Computer 24(5):303-322, 2008. (SCI) (NSC96-2221-E-011-139-)
(7) Min-te Sun, Chih-wei Yi, Chuan-kai Yang, Ten-hwang Lai, “An Optimal Algorithm for The Minimum Disc Cover Problem”, Algorithmica 50(1):58-71, 2008. (SCI)
(6) Chuan-kai Yang and Tzi-cker Chiueh, “Time-Critical Rendering of Tetrahedral Meshes”, Journal of Information Science and Engineering 23(5):1437-1451, 2007. (SCI) (NSC-91-2218-E-011-005-)
(5) Chih-chung Lin and Yuan-cheng Lai and J. D. Tygar and Chuan-kai Yang and Chi-lung Chiang, “Coexistence Proof Using Chain of Timestamps for Multiple RFID Tags”, Lecture Notes in Computer Science 4537/2007 (Advances in Web and Network Technologies, and Information Management), pp. 634-643, 2007.
(4) Jia-wei Chiou and Chuan-kai Yang, “A New Algorithm for Solid Texture Synthesis”, Lecture Notes in Computer Science 4292/2006 (Advances in Visual Computing), pp. 780-789, 2006. (SCI)
(3) Hui-lin Yang and Chuan-kai Yang, “A Non-photorealistic Rendering of Seurat's Pointillism”, Lecture Notes in Computer Science 4292/2006 (Advances in Visual Computing), pp. 760-769, 2006. (SCI)
(2) Chuan-kai Yang and Tzi-cker Chiueh, “Integration of Volume Decompression and Out-of-Core Iso-Surface Extraction from Irregular Volume Data”, The Visual Computer 22(4): 249-265 (2006). (SCI) (NSC-92-2213-E-011-082-)
(1)
Tzi-cker, Tulika Mitra, Anindya Neogi and Chuan-kai Yang, 2000, “Zodiac: A History-Based Interactive Video Authoring System”, Multimedia Systems, Volume 8, Issue 3, Page 201-211. (SCI)

Referred 
Conference
Publications

(22) 陳彥秀 and 楊傳凱, 2010, July, 居家風水自動化室內設計系統, Computer Graphics Workshop 2010 (CGW 2010).
(21)
蘇錦芬 and 楊傳凱, 2010, July, 三維模型串珠化, Computer Graphics Workshop 2010 (CGW 2010).
(20)
陳佑鈞 and 楊傳凱, 2009, July, 以手勢為主之視窗互動介面, Computer Graphics Workshop 2009 (CGW 2009).
(19) 周家愷 and 楊傳凱, 2009, July, “Automatic Hair Cutting and Cloning”, Computer Graphics Workshop 2009 (CGW 2009).
(18)
蔡青揚 and 楊傳凱, 2009, July, “3D建築原型拼貼”, Computer Graphics Workshop 2009 (CGW 2009).
(17)
Hsing-Chin Chang, Chuan-kai Yang, 2008, August, Content-Aware Video Resizing in Temporal and Spatial Domain”, The 21th IPPR Conference on Computer Vision Graphics and Image Processing (CVGIP 2008).
(16) Chih-chung Lin and Yuan-cheng Lai and J. D. Tygar and Chuan-kai Yang and Chi-lung Chiang, 2007, June, “Coexistence Proof Using Chain of Timestamps for Multiple RFID Tags”, International Workshop on Application and Security Service in Web and Pervasive Environments (ASWAN 2007), pp. 634-643.
(15) Jia-wei Chiou and Chuan-kai Yang, 2006, November, “A New Algorithm for Solid Texture Synthesis”, Internatinal Symposium on Visual Computing (ISVC‘2006), pp. 780-789.
(14) Hui-lin Yang and Chuan-kai Yang, 2006, November, “A Non-photorealistic Rendering of Seurat's Pointillism”, Internatinal Symposium on Visual Computing (ISVC ‘2006), pp. 760-769.

(13) Min-Te Sun, Xiaoli Ma, Chih-Wei Yi, Chuan-Kai Yang and Ten-Huang Lai, 2005, August, “Minimum Disc Cover Set Construction in Mobile Ad Hoc Networks” Proceeding of 2005 International Conference on Computer Networks and Mobile Computing (ICCNMC'05).
(12)
Chuan-Kai Yang and Tzi-Cker Chiueh , 2005, June, “Integration of Volume Decompression and Out-of-Core Iso-Surface Extraction from Irregular Volume Data”, poster paper, Proceeding of International Workshop on Volume Graphics.
(11) Chuan-Kai Yang and Tzi-Cker Chiueh, 2005, June, “An Integrated Pipeline of Decompression, Simplication and Rendering for Irregular Volume Data”, Proceeding of International Workshop on Volume Graphics.
(10) Chiang-Han Hung and Chuan-kai Yang, 2005, June, “A Simple and Novel Seed-Set Finding Approach for Iso-Surface Extraction” Proceeding of EuroVis2005.
(9)
Chiang-Han Hung and Chuan-kai Yang, 2004, December, “A New Approach of Seed-Set Finding for Iso-Surface Extraction”, Proceeding of international computer symposium (ICS 2004).
(8) Chuan-kai Yang, Tulika Mitra and Tzi-cker Chiueh, 2002, June, “A Decoupled Architechture for Application-Specific File Prefetching”, FREENIX Track of the USENIX 2002 Annual Conference, Page 157-170.
(7) Chuan-kai Yang and Tzi-cker Chiueh, 2001, May, “I/O Conscious Volume Rendering”, VisSym 2001, Joint Eurographics – IEEE TCVG Symposium on Visualization.
(6) Chuan-kai Yang, Tulika Mitra and Tzi-cker Chiueh, 2000, October, “On-the-Fly Rendering of Losslessly Compressed Irregular Volume Data”, IEEE Visualization 2000, Page 101-108.
(5) Tulika Mitra, Chuna-kai Yang and Tzi-cker Chiueh, 2000, July, “Application-Specific File Prefetching for Multimedia Programs”, IEEE International Conference on Multimedia and Expo (I) 2000, Page 459-462.
(4) Tzi-cker Chiueh, Tulika Mitra, Anindya Neogi and Chuan-kai Yang, 1998, September, “Zodiac: A History-Based Interactive Video Authoring System”, ACM Multimedia 1998, Page 435-444.
(3) Tzi-cker Chiueh, Chuan-kai Yang, Taosong He, Hanspeter Pfister and Arie Kaufman, 1997, October, “Integrated Volume Compression and Visualization”, IEEE Visualization 1997, Page 329-336
(2) Ming Ouhyoung and Chuan-kai Yang, 1993, August, “The Synthesis of a Cavern with Eroded Stalactites and Stalagmites”, Proc. Of CAD/Graphics’93, Page 125-129.
(1) Chuan-kai Yang and Ming Ouhyoung, 1992, “A Stalactite Cave by Stochastic Modeling with Radiosity Illumincation”, Proc. of 1992 International Computer Symposium, Volume 2, Page 976-983.

Technical
Reports

(6) and Chuan-kai Yang, 2005, July, “A Character-Based Animation System”.
(5) 張佑瑋and Chuan-kai Yang, 2005, July, “Automatic grayscale image colorization”.
(4) 毛紹嘉and Chuan-kai Yang, 2004, July, “3D Model Alignment”.
(3) Chuan-kai Yang, 2002, August, “On-the-Fly Processing of Compressed Volume Data”, Phd Dissertation.
(2) Chuan-kai Yang, 2001, October, “On-the-Fly Processing of Compressed Volume Data”, Dissertation Proposal Report.
(1) Chuan-kai Yang, 2000, September, “Integration of Volume Compression and Visualization: A Survey”, Research Proficiency Exam Report.

Languages

C/C++, Java, (Visual) Basic, Tcl/Tk, OpenGL, C Shell, Scheme, ML, SmallTalk, SQLwindows, Fortran, Pascal, 80x86 Assembly, 

Platforms

Linux, FreeBSD, Solaris, SunOS, Irix, Dos/Windows

References

(In alphabetical order) 
Prof. Tzi-cker Chiueh (advisor) 
Department of Computer Science 
State University of New York at Stony Brook 
Stony Brook, NY 11794-4400 
(O)+1-631-632-8449 
(F)+1-631-632-8334
chiueh@cs.sunysb.edu 

Prof. Kwan-liu Ma
Department of Computer Science 
2063 Engineering II 
University of California-Davis 
One Shields Avenue 
Davis, CA 95616-8562 
(O)+1-530-752-6958 
(F)+1-530-752-4767 
ma@cs.ucdavis.edu 

Prof. Klaus Mueller
Department of Computer Science 
State University of New York at Stony Brook 
Stony Brook, NY 11794-4400 
(O)+1-631-632-1524 
(F)+1-631-632-8334
mueller@cs.sunysb.edu 

Prof. Ming Ouhyoung
Department of Computer Science and Information Engineering 
National Taiwan University 
1 Roosevelt Rd. Sec. 4, Taipei, 106 Taiwan 
(O)+886-2-2362-5336 Ext.421 
(F)+886-2-2362-8167 
ming@csie.ntu.edu.tw