My main research area concerns the development of parallel preconditioners for accelerating the convergence of KSP iterative methods. I am also working on applications of such methods to specific problem domains, for example, computing small eigenvalues of sparse matrices generated in quantum nanotechnology, and in spectral element methods for nonlinear PDE's. My interests lie in developing new algorithms and their efficient implementations with respect to cache hierarchies and data partitioning for multiprocessors.
Details are described in my Research Statement
Towards Block Incomplete Factorization Preconditioning, I. Lee, 2007, draft.
Sparse Matrix Vector Multiplication using Compressed Graph, I. Lee, 2008, draft.
Augmented Spanning Tree Preconditioner for Iterative Solvers, I. Lee, P. Raghavan, 2008, draft.
Program Phase Detection using Spectral Analysis, I. Lee, P. Raghavan, 2008, draft.
Characterizing Communication Patterns of NAS-MPI benchmark programs, I. Lee, P. Raghavan, 2008, waiting for submission.
Multithreaded Preconditioned Conjugate Gradient (mtPCG): Sparse Iterative Solver, I. Lee, P. Raghavan, 2007,
waiting for submission.
Refereed Publications
Scientific Algorithms: Performance, Power, Thermal
Properties on Modern Computing Architectures, I. Lee, P. Raghavan,
Workshop on Unique Chips and Systems (UCAS-3), 2007, accepted (8 pages).
Si Nanotrees: Structure and Electronic Properties,
M. Menon, E. Richter, I. Lee and P. Raghavan, Journal of
Computational Theoretical Nanoscience, 4, 252-256, 2007.
On Improving Performance and Energy Profiles of Sparse Scientific Applications,
K. Malkowski, I. Lee, P. Raghavan and M. Irwin, Workshop on NFS Next
Generation Software, in conjunction with IPDPS, 2005, (8 pages).
Conjugate Gradient Sparse Iterative Solvers: Performance-Power Characteristics,
K. Malkowski, I. Lee, P. Raghavan and M. Irwin, The Second Workshop
on High-Performance, Power-Aware Computing, in conjunction with
IPDPS, 2005, (8 pages).
Large Scale Simulations of Branched Si-Nanowires,
M. Menon, E. Richter, I. Lee and P. Raghavan, The IEEE/ACM
International Workshop on High Performance Computing for
Nano-science and Technology, held in conjunction with Supercomputing
05, (5 pages).
Effective Preconditioning through Ordering Interleaved with Incomplete Factorization,
I. Lee, P. Raghavan, and E. G. Ng. SIAM Journal on Matrix Analysis and Applications, Vol. 27, Issue4, pp. 1069-1088, 2006.
An O(nlogn) Solution Algorithm for Spectral Element Methods,
I. Lee, P. Raghavan, S. Schofield and P. Fisher, Computational Fluid and Solid Mechanics 2003,
Proceedings of the Second MIT Conference on Computational Fluid and Solid Mechanics, Editor K.J.Bathe,
Volume 2. pp.2039-2042, June 2003.
Thesis
Sparse Scientific Applications: Improving Performance and Energy Characteristics on Advanced Architectures, I. Lee, Ph.D. Thesis, Pennsylvania State University, Department of Computer Science and Engineering, December, 2006.
Tools for Inherent Latency Analysis in Processing Graph Method Applications,
I. Lee, M.S. Thesis, University of Nebraska in Lincoln, Department of Computer Science and Engineering, August, 2000.
Presentations
Scientific Algorithms: Performance, Power, Thermal
Properties on Modern Computing Architectures, I. Lee, P. Raghavan,
Workshop on Unique Chips and Systems (UCAS-3), San Jose, CA. April 25, 2007.
PxP: Co-Managing Quality-Performance-Power Tradeoffs,
S. Akioka, I. Lee, K. Malkowski, S. Kennedy, M.J. Irwin, P. Raghavan, L.C. McInnes, and
B. Norris, Supercomputing 2005, Seattle, WA. November 15, 2005.
Large Scale Simulations of Branched Si-Nanowires,
I. Lee, P. Raghavan, M. Menon and E. Richter, The IEEE/ACM International Workshop on High Performance Computing
for Nano-science and Technology, Seattle, WA. November 16, 2005.
Ordering Schemes for Preconditioning with Sparse Incomplete Factors,
I. Lee, P. Raghavan and E. G. Ng, 2003 International Conference on Preconditioning
Techniques for Large Sparse Matrix Problems in Scientific and Industrial Applications, Napa, CA. October 27-29, 2003.
An O(nlogn) Solution Algorithm for Spectral Element Methods,
I. Lee, P. Raghavan, S. Schofield, and P. Fisher, Second MIT Conference on
Computational Fluid and Solid Mechanics, Massachusetts Institute of Technology,
Boston, MA, June 17-20, 2003.
Software
sHotSpot: HotSpot (Heat modeling and solution software) using spectral methods -- In progress
