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[ Network/graph analysis |
Sparse matrix computations |
Parallel computing |
CS education |
Other ]
At the moment I'm mostly thinking about network analysis.
Other research interests include sparse matrix
computations, high performance
computing (particularly performance modelling), algorithms, and
computer science education.

Below (in no particular order) is more information on various aspects
of my work. Some publications are listed in more than one category.
A [*] indicates that a co-author was an undergraduate at the time they did
the work. A [**] indicates that a co-author was a post-baccalaureate
researcher.

**Some topics of interest:**
preconditioners
perfect-elimination orderings
fill-reducing orderings
incomplete LU preconditioners
balancing sparse
matrices

**Publications:**
L. Peairs** and T.-Y. Chen.
Using reinforcement learning to vary the m in GMRES(m).
*Proceedings of the 2011 International Conference on Computational Science*,
also *Procedia Computer Science*, 4: 2257–2266. 2011.
<
ScienceDirect link>
E. Kuefler* and T.-Y. Chen.
On using reinforcement learning to solve sparse linear systems.
* Proceedings of the International
Conference on Computational Science*, also * Lecture Notes
in Computer Science*, 5101: 955-964, 2008.
<DOI link>
A. Holloway** and T.-Y. Chen.
Neural networks for predicting the behavior of preconditioned
iterative solvers. * Proceedings of the International
Conference on Computational Science*, also * Lecture Notes
in Computer Science*, 4487: 302--309, 2007.
<DOI link>
<pdf>
M. Lazzareschi* and T.-Y. Chen.
Using performance profiles to evaluate preconditioners for
iterative methods. * Proceedings of the 2006 International
Conference on Computational Science and its Applications*,
also * Lecture Notes in Computer Science*, 3982: 1081--1089,
2006. <DOI link>
T.-Y. Chen and M. Egan**.
On the existence of nonsymmetric matrices with perfect elimination
orderings. * Proceedings of the Fifth Grace Hopper Celebration
of Women in Computing*, 2004. <pdf>
<ps>
T.-Y. Chen. ILUTP_Mem: A space-efficient incomplete LU
preconditioner, * Proceedings of the 2004 International
Conference on Computational Science and its Applications*,
also * Lecture Notes in Computer Science*, 3046: 31--39,
2004. <springerlink>
T.-Y. Chen and J. Demmel. Balancing sparse matrices for
computing eigenvalues. * Linear Algebra and Its Applications*,
309: 261--287, 2000.
<pdf>
<ps>
T.-Y. Chen and J. Demmel. Balancing sparse matrices for
computing eigenvalues. Section 7.2 in * Templates for the
Solution of Algebraic Eigenvalue Problems: A Practical Guide*.
Editors Z. Bai, J. Demmel, J. Dongarra, A. Ruhe, and H. van der
Vorst. SIAM, Philadelphia, 2000. <online book>
T.-Y. Chen, J. Gilbert, and S. Toledo. Toward an efficient
column minimum degree code for symmetric multiprocessors.
* Proceedings of the 9th SIAM Conference on Parallel Processing
for Scientific Computing*, 1999.
<pdf>
<ps>

**Posters:**
L. Peairs** and T.-Y. Chen.
On the effect of varying the restart parameter of GMRES(m).
In Grace Hopper Celebration of Women in Computing.
Atlanta, GA. September 2010.
S. Ehrlich* and T.-Y. Chen.
Minimum fill with column permutations is NP-complete. In SIAM
Workshop on Combinatorial Scientific Computing. Monterey, CA.
October 2009.
A. Holloway** and T.-Y. Chen.
Using supervised machine learning techniques to understand
preconditioner behavior. In SIAM Conference on Computational
Science and Engineering. Costa Mesa, CA. February 2007.

**Theses:**
T.-Y. Chen. Preconditioning sparse matrices for computing
eigenvalues and solving linear systems of equations. Ph.D. Thesis,
Computer Science Division, UC Berkeley, 2001.
<pdf> <abstract>
T.-Y. Chen. Balancing sparse matrices for computing eigenvalues.
Masters Thesis, Computer Science Division, UC Berkeley, 1998.
<ps>
<pdf>

**Some topics of interest:**
performance modeling
workload characterization
algorithms

**Publications:**
S. Bhowmick, T.-Y. Chen, and M. Halappanavar.
A new augmentation based algorithm for extracting maximal chordal subgraphs.
*Journal of Parallel and Distributed Computing*, 2015.
<ScienceDirect link>
T.-Y. Chen, O. Khalili, R. L. Campbell Jr., L. Carrington,
M. Tikir, and A. Snavely. Performance prediction and ranking
of supercomputers. Chapter 3 in *High Performance Computing*,
volume 72 in series *Advances in Computers*.
Academic Press, 2008.
T.-Y. Chen, M. Gunn*, B. Simon,
L. Carrington, and A. Snavely. Metrics for ranking the
performance of supercomputers. *Cyberinfrastructure
Technology Watch*, 2(4B): 59--67, November 2006.
<html>
T.-Y. Chen, J. Gilbert, and S. Toledo. Toward an efficient
column minimum degree code for symmetric multiprocessors.
* Proceedings of the 9th SIAM Conference on Parallel Processing
for Scientific Computing*, 1999.
<pdf>
<ps>
<overview>
T.-Y. Chen. The effect of caches on the performance analysis of
data parallel CM-Fortran programs. *Proceedings of
the 1994 MIT Student Workshop on Scalable Computing*,
MIT LCS TR-622, 1994.

** Some topics of interest: **
Diversity, outreach
Pre-conceptions, pre-existing knowledge (Commonsense Computing group)
Student approaches to design
( Multi-national,
multi-institutional study of student-generated software designs )

**Publications:**
D. Bouvier, T.-Y. Chen, G. Lewandowski, R. McCartney, K. Sanders, and T. VanDeGrift. User evaluation by novices. *Proceedings of the 17th Annual Conference on Innovation and Technology in Computer Science Education (ITiCSE)*, 2012.
<ACM DL link>
M. Gonzalez, L. Vasserman, S. Sood, and T.-Y. Chen. Leveraging
existing outreach programs to reach underrepresented minorities,
in Proceedings of *the Fourth Annual Conference of the
Southwestern Region of the Consortium for Computing Sciences in
Colleges*, 2011.
<pdf>
T. VanDeGrift, D.
Bouvier, T.-Y. Chen, G. Lewandowski, R. McCartney, K.
Sanders, and B. Simon.
Commonsense computing (episode 7): Logic is harder than pie,
* Proceedings of 10th Koli Calling International Conference
on Computing Education Research*. October 2010.
G. Lewandowski, D.
Bouvier, T.-Y. Chen, R. McCartney, K.
Sanders, B. Simon, and T. VanDeGrift.
Commonsense understanding of concurrency: Computing
students and concert tickets, *Communications of the ACM*,
53(7): 60-70. July 2010.
<
DOI link>
R. McCartney, D.
Bouvier, T.-Y. Chen, G. Lewandowski, K.
Sanders, B. Simon, and T. VanDeGrift.
Commonsense probability: Preconceptions of entering engineering students, In
Proceedings of *Frontiers in Education*
(FIE),
2009.
San Antonio, TX
<pdf>
R. McCartney, D.
Bouvier, T.-Y. Chen, G. Lewandowski, K.
Sanders, B. Simon, and T. VanDeGrift.
Commonsense computing (episode 5): Algorithm
efficiency and balloon testing, In
Proceedings of the *2009
International Computer Science Education Research Workshop*
(ICER),
2009.
Berkeley CA.
<
DOI link>
B. Simon, D. Bouvier, T.-Y. Chen,
G. Lewandowski, R. McCartney,
and K. Sanders.
Commonsense computing (episode 4): Debugging. *Computer
Science Education, special issue on debugging*, 18(2): 117-133, 2008.
T.-Y. Chen, G. Lewandowski, R. McCartney, K. Sanders, and B. Simon.
Commonsense Computing: using student sorting abilities to improve
instruction. In Proceedings of
SIGCSE, 2007.
<DOI link>
B. Simon, T.-Y. Chen, G. Lewandowski, R. McCartney, and K. Sanders.
Commonsense computing: What students know before we teach (Episode
1: Sorting). In the Proceedings of the * 2006
International Computer Science Education Research Workshop *
(ICER),
2006. Canterbury, UK.
<DOI link>
T.-Y. Chen, A. Monge, and B. Simon. Relationship of early
programming language to novice generated design. In
Proceedings of the * 2006 Technical Symposium on Computer Science
Education * (SIGCSE),
2006. <DOI
link>
T.-Y. Chen, S. Cooper, R. McCartney, and L. Schwartzman.
The (relative) importance of software design criteria.
In Proceedings of the * 10th Annual Conference
on Innovation and Technology in Computer Science Education
* (ITiCSE), 2005.
Also SIGCSE Bulletin, 37(3): 34--38, September 2005.
<DOI link>
S. Fincher, M. Petre, J. Tenenberg, K. Blaha, D. Bouvier,
T.-Y. Chen, D. Chinn, S. Cooper, A. Eckerdal, H. Johnson,
R. McCartney, A. Monge, J. E. Mostrom, K. Powers, M. Ratcliffe,
A. Robins, D. Sanders, L. Schwartzman, B. Simon, C. Stoker,
A. E. Tew, T. VanDeGrift. Cause for alarm?: A multi-national,
multi-institutional study of student-generated software
designs. In the Proceedings of the *4th Annual Finnish/Baltic Sea
Conference on Computer Science Education*, 2004. Invited to
Informatics in Education, 4(1): 143--162, 2005. (Earlier
version available as tech report: University of Kent,
Canterbury: Computing Laboratory, Technical Report No. 16-04,
2004. <abstract>
<pdf>)

**Posters:**
T.-Y. Chen, G. Lewandowski, R. McCartney, K. Sanders, and B. Simon.
What do beginning students know, and what can they do?
In Proceedings of the * 11th Annual Conference
on Innovation and Technology in Computer Science Education
* (ITiCSE), 2006.
Also SIGCSE Bulletin, 38(3): 329, September 2006.
<DOI
link>

**Publications:**
P. McCormack* and T.-Y. Chen. Optimizing
leader proportion and behavior for evacuating buildings.
*Proceedings of the Symposium on Agent-Directed Simulation*, 2014.
S. Azenkot*, T.-Y. Chen, and G. Cormode.
An evaluation of the edit-distance-with-moves metric for
comparing genetic sequences. DIMACS Technical Report 2005-39,
November 2005. <abstract>
<ps.gz>

[*] work done while an undergraduate researcher

[**] work done while a postbaccalaureate
researcher

The research on sparse matrices was funded in part by
an NSF
CAREER grant (abstract).

The research in computer science education was funded in part by
an NSF CCLI
grant. (abstract).

"If we knew what it was we were doing, it would not be
called research, would it?"

-- Albert Einstein