Li Chen's Homepage

		Li Chen, Ph.D. Associate Professor   Department of Computer Science and Information Technology University of the District of Columbia 4200 Connecticut Avenue, N.W. Washington, DC 20008 Office 42/112-A Office Tel: (202) 274-6301 Email: lchen (at) udc.edu
		Major New Research: Digital-Discrete Fitting for Smoothed Functions
		Books: Li Chen, Discrete Surfaces and Manifolds, June 2004.

Education

	Ph.D.  University of Bedfordshire (Renamed from U of Luton, Luton, UK), 2001. Advisor: Dr. Osei Adjei.
		PhD Thesis: lambda-connectedness and  its application to image segmentation, recognition, and reconstruction.
	MS of Computer Science, Utah State University (Logan, USA), 1995.  Advisor: Dr. Don Cooley
		MS Thesis: Possibility functions based fuzzy neural networks and their applications to image processing
	BS of Computer Science, Wuhan University (Wuhan, China), 1982.     Advisor:  Li Qrong-Zhang
		BS Dissertation: Matrix representations of some combinatorial problems and their applications.

More about the three thesis and related publications.

Current Research and Teaching Areas:

• Image Processing
• Object Oriented Design and Programming
• Algorithm Design and Complexity
• Fall 2009 Courses: Theory of Computing, Design and Analysis of Algorithms (Grad), Senior Projects, Senior Seminars. (udc.blackboard.com)

Current Research Topics:

• 3D Object Recognition, Tracking and Search  
• Digital and Discrete Geometry  
• Algorithms for Finite Groups 

Recent Talks:

• Chen, Discrete Immersion and Gradually Varied Extension, The Workshop on Whitney’s Problem, College of William and Mary, Aug 3-8, 2009. The Workshop was organized by Princeton and WM.

• Chen, Graph homomorphism and gradually varied functions, DIMACS Mixer Series, October 21, 2008. Rutgers University.

• Chen, Algorithms and Complexity: Recent Development, March 6, 2009, Virginia Tech.  (http://www.nvc.cs.vt.edu/~ctlu/Course/2009/CS5944/Abs/Seminar-Chen.pdf) 

Publications (Publication List):

• Recent Articles
  • L. Chen, Y. Rong, Linear Time Recognition Algorithms for Topological Invariants in 3D,  Proceedings of  International Conference on Pattern Recognition 2008.
  • L. Chen_and B. Fu, Linear and sublinear time algorithms for the basis of Abelian groups, Electronic Colloquium on Computational Complexity, Report TR07-052, 2007 (ISSN 1433-8092, 14th Year, 52nd Report, 2007) 
  • C-T Lu, Y. Kou, J. Zhao, and L. Chen, Detecting and Tracking Region Outliers in Meteorological Data, Information Sciences,   Volume 177, Issue 7, 1 April 2007, Pages 1609-1632.
• Most Significant Articles (in Author's View, the descriptions are based on the author's best knowledge ) 
  • Chen, The necessary and sufficient condition and the efficient algorithms for gradually varied fill, Chinese Science Bulletin, 35:10(1990). (German Math Abstract-Zbl 0712.68085), It can also be found in the Abstracts of SIAM Conference on Geometric Design, 1989.  The World's first pure discrete method for discrete surface interpolations. (Experts' comments)
  • Chen and J. Zhang, Digital manifolds: An intuitive definition and some properties, In Proceedings of Second ACM Symp. on Solid Modeling and Applications, pp 459-460, 1993. The World's first mathematical definition to digital manifolds. (Experts' comments) 
  • Chen, An optimal generating algorithm for matrix of equal-weight column and quasiequal-weight row, Journal of Nanjing Institute of Tech, 2(1986). (German Math Abstract-Zbl, Zbl 0629.65046 In Chinese). This paper gives the first polynomial time algorithm to the Check Matrix of the World famous SEC-DED error correction code (Hsiao-codes). Introduced so-called the recursive combinatorial matrix. (Experts' comments) 
  • Chen, Algorithms and their complexity analysis for some problems in finite group. Journal of Sandong Normal University, (in Chinese), 2:27–33, 1984. This paper gives the first polynomial time algorithm to find the basis of finite Abelian Groups. It also gives (possibly the World's) first constructive proof for famous Fundamental Theorem of Finite Abelian Groups. (Experts' comments)
  • Chen and J. Zhang, Classification of simple digital surface points and a global theorem for simple closed surfaces, Vision Geometry II, Proc. SPIE Vol. 2060, 1993. (Mathematical Review) This paper first discovered exact 6-types of digital surface points in 3D digital space (in direct adjacency). It has the great importance in computing the genus and homology groups in 3D. (Experts' comments)     

    Again the above descriptions are based on the author's best knowledge. Will post correction when an error is found.

• Major Achievements in Theory and Methodology

• Chen, Discrete Surfaces and Manifolds,  SP Computing, June 2004.  Systematic work for developing a theory for digital topology. Cited by leading scientists in related areas in IEEE Trans on PAMI, Discrete Applied Mathematics, Pattern Recog etc.  (Experts' comments)   

• Chen, Gradually varied surfaces and gradually varied functions,  CITR-TR 156, The University of Auckland, 2005. Directly translated from a paper in Chinese with the same title written in 1990. This paper conducted a deep research to establish a totally new method for discrete surface reconstruction.  More information.

• (With H-D Cheng, J. Zhang, T. F. Berkey, D. H. Cooley, Lu, et al) lambda-connected image segmentation. More than 15 papers were published attempting to develop a widely-applicable method for image segmentation which is essential to image processing and computer vision. (Experts' comments)   

• Most Cited Articles
  • Chen and P. Wang, Fuzzy Relation Equations (I): The General and Specialized Solving Algorithms, Journal of Soft Computing, Vol 6, 428-435, 2002. (German Math Abstract-Zbl)  The paper was viewed as one of the most significant works for this topic.  Results are presented in two books. (Experts' comments) 
  • Chen, D. Cooley and J. Zhang, Equivalence between two definitions of digital surfaces, Information Sciences, Vol 115, 201-220, 1999.  (German Math Abstract-Zbl)   This article has been cited by a text book and other research papers. (Experts' comments)  

Awards :

• Outstanding Junior Faculty Award, SEAS, University of the District of Columbia 2005.
• One of the faculty members of Department of Computer Science who received Excellent Teaching Award from University of North Dakota in 2001.
• Outstanding Teacher of Wuhan University (1991)
• Outstanding Scientist of Wuhan University (1990)
• The Award Research Fund of The Academy of Science of China for Young Scientist (1987)
• Listed by  Who's Who in American  
• .....

Research and Professional Relations  

• Visiting Associate Professor, Oct. –Dec 2008, University of Maryland Institute for Advanced Computer Studies (UMIACS). 

• Visitor, Sept-Oct 2008, Center for Discrete Mathematics and Theoretical Computer Science (DIMACS), Rutgers U.– Princeton U.  

• May 2006-Aug. 2006, Adjunct professor in Computer Science, Virginia Tech. Class taught (Graduate Level):  Theory of Algorithms.

• Apr. 2004- 2006: Adjunct professor, Strayer University, Class Taught (Graduate level in Computer Information Systems):  Wireless Network Communications, and Client Server Computing. 

Software Development (under construction)

Other Links

• Luton University (UK)   England's newest university.  Now called University of Bedfordshire. 
• Utah State University The second research-one university in Utah. This is a link to Computer Science at USU.
• Wuhan University (China)(Click here for its English-Version) One of the top universities in China
• Spiricon, Inc. World leading company in Laser Beam Analysis.
• SorensonMedia, Inc. World leading company in Video Image Compression.

Li Chen has mixed features of computer science and software engineering. In the past twenty-five years, he has worked as a professional software engineer while retaining his career as an amateur computer scientist. He has also continued to develop computer software while working as a professional computer scientist and an educator.

He has published over 55 research papers in several areas of computer science and applied mathematics in research journals and conference proceedings including Discrete Mathematics, Chinese Science Bulletin, IEEE Tran.on SMC, Soft Computing, Information Sciences, and Chinese Journal of Computers. He has developed, both alone and jointly, over a dozen software systems and packages in various computer systems using different computer languages including Unix, PDP, IBM-PC, C/C++, FORTRAN, BASIC, TOOLBOOK, X-Windows, MS-Windows, etc.

His most important research contributions include:

His most important research contributions include:

• The definition of Gradually Varied Surfaces and discovery of the necessary and sufficient condition for Gradually Varied Interpolation. (A related paper was reviewed by Zbl and indexed by MR )
• (With J. Zhang and D. Cooley) The definition of Digital Manifolds in direct adjacency and the classification theorem for simple surface points in 3D digital spaces. (Three related papers were reviewed by Zbl and MR )
• The optimal algorithm for the Optimal Hamming code check matrix based a type of recursive matrix that he proposed.( The paper was reviewed by Zbl and indexed by MR)
• (With P.P. Wang) The branch-point solution in fuzzy relation equations
• (With H-D Cheng and J. Zhang) lambda-connected image segmentation   

His software developments include:

• The first special software system for lithology classification and oil-gas prediction in China.  He was the project leader, 1990. This software correctly identified an industrial gas trap.  
• World leading Spiricon M-square 101 for the laser beam propagation analysis system. He was the key programmer, 1995. This system was one of industry standard meaning that people use the device's measuring results  to compare their other research or lab results.
• World leading Spiricon LBA-PC for the laser beam profile analysis system. He was one of the key programmers, 1997. 
• The World leading video compressor by SorensonMedia, SorensonVideo 3 for Apple Computer QuickTime. (He was one of the key programmers who completed the pre-alpha version, 2000).

Chen has received many awards and honors. The most remarkable was the "Top 100 Young Scientist Award Fund" in China in 1987. He was also "a record holder" for the youngest person to publish a regular research paper alone in Chinese Journal of Computers, the best journal in computer science in China during that time in 1984 when he was 23 years old. This paper was reviewed by the Mathematical Review and Soviet Math Abstract. Chen wrote his first research paper in 1980 when he was 19 years old. The paper solved the Check-Matrix problem for (the nowadays World famous) Hsiao-codes. He also won the Student Research Paper Award of Wuhan University in 1981. It was published later and reviewed by the German Math Abstract (Zbl).

Chen was a very good Chinese flute player in his home county of Lishui, China when he was a high school student. He was a soloist for the Lishui County Spare-time Band (a highly selective traditional orchestra in the county).  He also enjoys classical music. He sometimes plays Ping-Pong, but he can be defeated very easily. He plays Chinese Chess sometimes and his skill in this event is a little bit better than his Ping-Pong technique.