This page is still being developed.

The papers on this page are concerned with my model for parallelism in distributed memory, I have incrementally develop the TOP-C (Task-Oriented Parallel C) model. A simple model requires that the performance issues concerned with when a message is sent or arrives should be hidden from the programmer, while not greatly impacting overal efficiency. Hence, I felt that the key issue in maintaining good efficiency under these conditions was latency tolerance. This led me to the three abstractions of this model.

I assume a master-slave architecture. The three abstractions are (1) the task, (2) the environment, and (3) the action. The environment is the globally shared data. The task is a procedure executed on a slave process that takes an input, and the environment, and produces a unique output. The action is the decision taken by the master process when it is presented with a task input-output pair. Example actions are NO_ACTION, REDO, UPDATE_ENVIRONMENT, and CONTINUATION(), and various hybrid strategies are possible. Most of the issues of efficient parallelization can then be reduced to the choice of definition of a taks, and what action to take for various input-output pairs.

Some of the features that come with this abstraction are easy reuse of "legacy" sequential code, easy checkpointing (sinc This parallel model has proved quite successful in a variety of examples of largest applications of their kind. At this time, my research issues are: the scalability of CPU's (> 100); scalability for large, distributed memory (> 1 GB); and extension of the model to SMP/DSM (hopefully with minimal rewriting of application code).

In addition to the papers below, the software implementations are available for C (TOP-C), GAP (ParGAP or Parallel Groups, Algorithms and Programming) and GCL (Parallel GNU LISP). Descriptions of applications done with these systems are available here.

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- ``Parallel GAP: Mature Interactive Parallel'', G.~Cooperman, {\sl Proceedings of Conference on Groups and Computation}, DeGruyter Publishers, 2000, to appear.
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- ``TOP-C: Task-Oriented Parallel C for Distributed and Shared Memory'', G. Cooperman, Workshop on Wide Area Networks and High Performance Computing, Lecture Notes in Control and Information Sciences 249, 1999, Springer Verlag, pp. 109-118.
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- ``TOP-C: Task-Oriented Parallel C for Distributed and Shared Memory'',
G. Cooperman,
Lecture Notes in Control and Information Sciences
**249**, 1999, Springer Verlag - o
- ``TOP-WEB: Task-Oriented Metacomputing on the WEB'',
G. Cooperman and V. Grinberg,
*International Journal of Parallel and Distributed Systems and Networks***1**, 1998, pp. 184-192 - o
- ``TOP-WEB: Task-Oriented Metacomputing on the Web'',
G. Cooperman and V. Grinberg,
*Proceedings of Ninth IASTED International Conference on Parallel and Distributed Computing and Systems*(PDCS-97), IASTED/Acta Press, Anaheim, 1997, pp. 279-286 - o
- ``Practical Task-Oriented Parallelism for Gaussian Elimination
in Distributed Memory'', G. Cooperman,
*Linear Algebra and its Applications***275-276**, 1998, pp. 107-120 - o
- ``Using Tadpoles to Reduce Memory and Communication Requirements
for Exhaustive, Breadth-First Search Using Distributed Computers'',
G. Cooperman and M. Tselman,
*Proc. of ACM Symposium on Parallel Architectures and Algorithms*(SPAA-97), ACM Press, 1997, pp. 231-238; also N.U. Tech. Rept. NU-CCS-97-02, 1997 - o
- ``Practical Parallel Coset Enumeration'', G. Cooperman and G. Havas,
*Proc. of Workshop on High Performance Computation and Gigabit Local Area Networks*, Lecture notes in control and information sciences**226**, Springer Verlag, 1997, pp. 15-27 - o
- ``GAP/MPI: Facilitating Parallelism'', G. Cooperman,
*Proc. of DIMACS Workshop on Groups and Computation II***28**,*DIMACS Series in Discrete Mathematics and Theoretical Computer Science*, AMS, Providence, RI, 1997, pp. 69-84. - o
- ``New Sequential and Parallel Algorithms
for Generating High Dimension Hecke Algebras
using the Condensation Technique'', G. Cooperman and M. Tselman,
*Proc. of International Symposium on Symbolic and Algebraic Computation (ISSAC '96)*, ACM Press, 1996, pp. 155-160 - o
- ``TOP-C: A Task-Oriented Parallel C Interface'', G. Cooperman,
*5*(HPDC-5), IEEE Press, 1996, pp. 141-150^{th}International Symposium on High Performance Distributed Computing - o
- ``Computing with Matrix Groups using Permutation Representations'',
G. Cooperman, L. Finkelstein and M. Tselman,
*Proc. of International Symposium on Symbolic and Algebraic Computation (ISSAC '95)*, ACM Press, 1995, pp. 259-264 - o
- ``STAR/MPI: Binding a Parallel Library to Interactive
Symbolic Algebra Systems'', G. Cooperman,
*Proc. of International Symposium on Symbolic and Algebraic Computation (ISSAC '95)*, ACM Press, 1995, pp. 126-132 - o
- ``Parallel Implementations of Group Membership and the Method
of Random Subproducts'', G. Cooperman, L. Finkelstein, and B. York,
*Proc. of 1992 Dartmouth Institute for Advanced Graduate Studies in Parallel Computation Symposium (DAGS'92)*, D. Johnson, F. Makedon, and P. Metaxas (eds.), Department of Mathematics and Computer Science, Dartmouth College, pp. 94-100, June 17-20, 1992