Department of Electrical and Computer Engineering

Parallel and Distributed Computing

Externally Funded Research Projects

MATCH: A MATLAB Compilation Environment for Adaptive Computing Systems

Investigators: P. Banerjee, A. Choudhary, S. Hauck

Sponsor: Defense Advanced Research Projects Agency (DARPA), 4/98 – 3/01

Adaptive computing systems constitute a new class of computing and communication technology composed of configurable hardware capable of system-level adaptation. Such systems are often built out of combinations of microprocessor-based embedded systems, specialized digital signal processors (DSP’s), and field-programmable gate arrays (FPGA’s). The objective of the MATCH (MATLAB Compiler for Heterogeneous adaptive computing systems) project is to make it easier for users to develop efficient codes for adaptive computing systems. As part of this project, we are developing a compiler that allows input of a user’s applications written in the high-level language, MATLAB, and generates efficient low-level code that runs on commercial off-the-shelf FPGA’s, embedded processors, and DSP’s. Our specific aims include:

• development of a hardware testbed consisting of commercial FPGA’s, embedded processors,
and DSP’s;

• development of a basic compiler for mapping a given MATLAB application onto this
heterogeneous target;

• investigation of automated parallelization and mapping techniques;

• design and support of compiler directives;

• development of library functions and applications of interest to DOD;

• development of faster algorithms for compilation.

PANTHER: A High-Performance Distributed Computing Infrastructure

Investigators: P. Banerjee, A. Choudhary, S. Hauck, D. T. Lee, M. Sarrafzadeh, P. Scheuermann,
and V. Taylor

Sponsor: National Science Foundation (NSF), 9/97 – 8/02

Specific aims of the PANTHER project include:

• exploration of using high-speed networking and computing to investigate file-systems and data-management issues for high-performance distributed computing;

• investigation of the parallel-programming support of networks of high-speed workstations and
personal computers as an alternative to stand-alone parallel computers;

• investigation of high-performance CAD of electronic systems in a heterogeneous environment;

• development of a Web-based CAD computing center that takes advantage of high-speed
networking;

• exploration of new instructional techniques that take advantage of high bandwidth and high
speed.

This project provides for the acquisition of 50 high-performance Hewlett-Packard C-180 UNIX workstations, 20 medium-performance B-132 UNIX workstations; 3 J-280 UNIX fileservers, an
8-processor Silicon Graphics Origin 2000 distributed shared-memory multiprocessor, and four CISCO systems LS1010 ATM switches. All of the machines are connected via an OC-3 ATM network operating at 155 Mbps.

PARADIGM: Efficient Compilation Issues in Distributed Memory Multicomputers

Principal Investigator: P. Banerjee

Sponsor: NSF, 9/96 – 9/99

In this research, we are developing efficient compilation and run-time techniques for optimized code generation for distributed-memory multicomputers and distributed shared-memory multiprocessors. We are producing the next generation PARADIGM compiler to handle general block, cyclic and block-cyclic data distributions in regular applications. We are also developing techniques using global dataflow analysis to perform redundant array access elimination. We are investigating techniques for handling regular and irregular codes in a uniform framework based on a runtime library.

Filtration Combustion for Microgravity Applications: (1) Smoldering; (2) Combustion
Synthesis of Advanced Materials

Investigators: A. Bayliss, B. J. Matkowsky, and V. Volpert (Applied Mathematics)

Sponsor: National Aeronautics and Space Administration (NASA), 6/1/94 – 11/30/98

In this grant, we study filtration combustion with an emphasis on combustion synthesis and smoldering. The objectives are to understand these processes, describe observed modes of combustion, and predict new modes. The investigations employ both analytical and numerical methods. We consider a variety of physical effects including cellular flames in filtration combustion, and the dynamics of solid-fuel combustion when melting occurs.

Investigation of Nuclear Burning on Neutron Stars

Investigators: A. Bayliss and R. Taam (Physics)

Sponsor: NASA , 2/15/98 – 2/14/99

We investigate the role of nuclear burning on accreting neutron stars in the X-ray burst phenomenon. Particular attention is focused on the study of instabilities of the burning front and its evolution to the previously unexplored pulsing regime. The ignition, nuclear evolution, and propagation of symmetric and asymmetric conductive burning fronts on the surface of a neutron star in multi-dimensional circumstances is investigated. Studies also include a multi-dimensional analysis of a nuclear burning front in which energy is transported by convection. We provide detailed treatments of the nuclear physics, thermodynamics, and gas dynamics using hydrodynamic, nuclear reaction network, and flame-propagation computer codes based on adaptive spectral and finite-difference methods that we previously developed. The results are used to determine the propagation speed and variability of the conductive and convective burning fronts, thereby providing fundamental understanding of nuclear burning on the surfaces of accreting neutron stars. The resulting influence of multi-dimensional effects on the X-ray light curve offers additional insights in interpreting the bursting behavior and variability seen in observed sources. Armed with these new theoretical models and the prospect of new observations with the Rossi X-Ray Timing Explorer, the potential for new insights into the X-ray burst phenomenon is high.

Non-Reflecting Boundary Conditions Based on Far Field Expansions

Principal Investigator: A. Bayliss

Sponsor: NSF, 7/96 – 6/99

In this project we develop, implement, and assess outer grid boundary conditions for wave-propagation problems that are based on far-field expansions of the solution. The methodology is to obtain a far-field expansion for the solution, for example, in terms of the distance from a given source location, and then derive outer boundary conditions as differential operators that annihilate progressively more terms in the expansion. Techniques of interest use interior information to improve the performance of the outer boundary conditions. This permits dealing with situations where the source location is not known in advance, where sources move, or where waves from different sources impinge on different portions of the boundary at the same time. We also develop techniques to increase the order of the outer boundary condition without increasing the order of the spatial derivatives in the boundary operator. This is done by incorporating inhomogeneous terms in the boundary condition derived from far-field expansions of the solution.

Nonlinear Dynamics in Combustion

Principal Investigator: A. Bayliss

Sponsor: NSF, 7/94 – 6/98

In this project we formulate and apply adaptive pseudospectral methods to numerically model the development of highly nonlinear space-time patterns in combustion. Pseudo-spectral methods are more accurate than commonly used finite-difference and finite-element techniques. Mesh adaptation provides increased spatial resolution of the narrow combustion reaction zones. We consider applications involving both gaseous and solid-fuel combustion. In gaseous combustion, we study flames stabilized on a rotating burner, and the effect of buoyancy on flames. In solid-fuel combustion, we study various modes that can occur in the self-propagating high-temperature synthesis process. We numerically simulate recently observed combustion modes involving counterpropagating hot spots. In addition, we analyze other modes, not yet observed, involving repeated reversals of the spinning direction of the hot spots.

Mathematical Sciences Computing Research Environments

Investigators: A. Bayliss and several faculty in Applied Mathematics

Sponsor: NSF , 8/96 – 7/98

This grant enabled acquisition of several Hewlett-Packard HP J2240 workstations to perform numerical analyses. Specific problems of interest include filtration combustion with application to materials synthesis, and pattern formation and nonlinear dynamics in gaseous combustion.

Compiler and Run-Time Optimization Techniques for Parallel Programming