NPAC REU '93 Abstracts and Papers

Kim Mills
Project Leader, NPAC, Syracuse University
kim@npac.syr.edu

This project addresses the development of a graphical user interface to the Geographical Resources Analysis Support System (GRASS), a geographical information system. The Application Visualization System (AVS) is used for the user interface. In addition to providing visualization capabilities, AVS also provides an software environment for applications that require distributed execution on a heterogeneous computer network. The intent of this project is to demonstrate how AVS can be used to access GRASS.

Thong Q. Dang
Associate Professor
Depart. Mech., Aero. and Manufact. Engr., Syracuse University
tqdang@mailbox.syr.edu

Edward A. Bogucz
Associate Professor
Depart. Mech., Aero. and Manufact. Engr., Syracuse University
bogucz@npac.syr.edu

Gang Cheng
Junior Research Scientist, NPAC, Syracuse University
gcheng@npac.syr.edu

This project demonstrates the use of the commercial software package AVS to animate the results of an unsteady viscous flow computation. The physical problem considered is the flow induced by a two-dimensional flat plate that is impulsively started in motion in a direction normal to its length in an otherwise quiescent fluid. The unsteady flow is calculated using a vorticity-streamfunction formulation that is approximated using a finite-volume technique. Computed results for individual time steps are stored as separate files for subsequent processing by AVS. The animation shows development of large-scale vortex structures in the wake of the plate.

C.-Y. Roger Chen
Associate Professor
Department of Electrical and Computer Engineering, Syracuse University
rchen@cat.syr.edu

The development of software for an element of Multimedia Database Management Systems (DBMS) is addressed in this work. The present contribution concentrates on the design of software to control a laser disk player. Once the laser disk player is controlled, each frame of the laser disk will be interfaced with a closed caption, and a search will be performed on the basis of the closed caption. Some applications of the work are found in areas of criminal identification, graphic art design, sports statistics and records, and the movie/video industry.

Wojtek Furmanski
Research Professor of Physics
Associate Director, NPAC, Syracuse University
fum@npac.syr.edu

Diglio A. Simoni
Graduate Research Assistant, NPAC, Syracuse University

The intent of this project was to explore the artistic potential of current virtual reality technologies. This involved achieving access to appropriate hardware, exploring an existing software package (Minimal Reality Toolkit), designing a virtual environment, and executing the environment. The desired outcome was a working minimal environment. Many unforeseen complications involving both the hardware and software arose, preventing the realization of this minimal environment. Alternatively, this project explored other existing (non-virtual reality) software (Application Visualization System and Aldus Superpaint), along with some current multi-user networks (Multi-User Dimensions) found on the internet. Experiences with these resources and exposure to some of the existing virtual reality technologies led to the conclusion that a more versatile interface for designing virtual environments needs to be developed for artists.

Paul D. Coddington
Project Leader, NPAC, Syracuse University
paulc@npac.syr.edu

Parallel random number generators are studied and tested on a variety of parallel computers. The performance of each random number generator is evaluated using parallel Monte Carlo simulations. A model with known results is used to enable a more precise analysis of each random number generator. The results of these parallel simulations are similar to those achieved with sequential simulations.

Mark J. Bowick
Associate Professor, Physics Department, Syracuse University
bowick@npac.syr.edu

The theory is investigated in order to determine whether direct simulation of Quantum Field Theory is a reasonable alternative to currently existing methods. Advantages and disadvantages of direct simulation are discussed. A new approach to perturbation theory similar in spirit to the direct simulation method is introduced, and the applications of this theoretical structure to large coupling constant field theoretic conditions are investigated, both numerically and analytically.

Paul D. Coddington
Project Leader, NPAC, Syracuse University
paulc@npac.syr.edu

James R. Allwright
Visiting Assistant Professor
School of Computer and Information Science, Syracuse University

A system for modeling random surfaces that can evolve with time, specifically for computer simulations of String Theory, requires a fast and efficient means for coloring the sites to ensure that adjacent sites are not updated simultaneously. Effective coloring algorithms are implemented on two different parallel architectures and tested for efficiency.

Gustav A. Engbretson
Associate Professor
Department of Bioengineering and Neuroscience, Syracuse University
gus_engbretson@isr.syr.edu

Ernest E. Sibert
Professor
School of Computer and Information Science, Syracuse University

Engbretson and Solessio developed a model for the reptilian parietal eye that predicts the intensity response relationship of the parietal eye of the lizard Xantusia vigilis to sunlight with a reasonable degree of accuracy. The program SOLRAD is used to predict the intensity of natural light. When the model is implemented on the CM-5 to analyze the data from SOLRAD, a response that suggests a possible function of the parietal eye is generated. The function proposed is a mechanism that is able to detect ``dimness" in sunlight, and in doing so, able to determine when the sun is rising or setting.

Eric F. Spina
Associate Professor
Depart. of Mech., Aero. and Manufact. Engr., Syracuse Univ.
eric@mars.mae.syr.edu

A procedure was developed for entering jet velocity data into a visualization package called AVS. Images of density gradients produced by the schlieren method and three-dimensional total pressure data were converted into AVS readable formats. These images will be used to investigate flow field structures in heated supersonic flow.

Paul D. Coddington
Project Leader, Northeast Parallel Architectures Center
Syracuse University
paulc@npac.syr.edu

Geoffrey C. Fox
Director, NPAC, Syracuse, NY
Professor, Physics and Computer Science
Syracuse University

Enzo Marinari
Associate Director, NPAC, Syracuse, NY
Professor of Physics, Syracuse University
Professor of Physics, Università di Roma Tor Vergata
Rome, Italy

C. H. Wu
Graduate Assistant, School of Computer and Information Science
Syracuse University

A study of global optimization schemes is presented. Simulated annealing, a general and proven technique for minimizing functions with many coexisting states, is used as a foundation for the development of a new, more automatic approach, called simulated tempering. This novel method upholds the eminent attribute of simulated annealing-the probabilistic guarantee of convergence upon a global minimum. It is unique, however, in that system equilibrium is never disturbed. Although simulated tempering is in its infancy, it is promising indeed, as the preliminary results suggest. The two-dimensional Ising Spin Glass Model, an NP-complete optimization problem, is used as the test case. Its theoretical formulation is briefly addressed.

Denis G. Pelli
Professor, Department of Bioengineering and Neuroscience
Syracuse University
denis_pelli@isr.syr.edu

QUEST-2 uses ideal sequential estimation procedures to minimize the expected variance of a threshold estimate after a series of tests. The ideal psychometric procedure incorporates QUEST and the ``lookahead'' factor into finding the minimal effective threshold in a series of trials. Since the minimization techniques involve expensive computations, a parallel implementation of QUEST-2 was developed in an attempt to increase its speed and computational power and to allow a greater lookahead factor. The effectiveness of the sequential and parallel versions are examined.

Michael J. Vinson
Research Associate, NPAC and Physics Department
Syracuse University

A method for controlling extended chaotic systems, chaotic systems with many degrees of freedom, by applying existing techniques is examined. Background is given about the control techniques of Ott, Grebogi, and Yorke, as well as those of Pyragas. The significance of the use of a coupled map lattice for modeling a system is explained. The results of applying the Pyragas control method to a zero-dimensional case, as well as to a coupled map lattice, are discussed.

Chilukuri K. Mohan
Associate Professor, School of Computer and Information Science
Syracuse University
mohan@top.syr.edu

This paper addresses the development of parallel algorithms for automated theorem-proving of propositional logic. Current sequential theorem-prover implementations are not used extensively in practice, as they are slow to run. Parallel algorithms have been shown to drastically decrease search times over the sequential code. Unfortunately, parallel algorithms can fall into the same traps of greedy sequential algorithms and not be able to find the contradiction. However, an existing sequential code motivated by the methodology of genetic algorithms has already achieved significant progress in speeding up the process sequentially. A parallelization of this code is explored.

Michael J. Vinson
Research Associate, NPAC and Physics Department
Syracuse University

Farmer and Sidorowich proposed a nonlinear prediction algorithm that could successfully predict chaotic systems in the short term. We make this algorithm more accurate, test its effectiveness when confronted by error, optimize its controlling parameters for several data sets, adjust it so that it predicts future direction instead of future values, and modify it to utilize data from several concurrent time series simultaneously. We then join this improved algorithm with a method for determining whether or not a time series is chaotic or merely random.

Edward A. Bogucz
Associate Professor
Department of Mechanical, Aerospace and Manufacturing Engineering
Syracuse University
bogucz@npac.syr.edu

Knotica, a high-level interactive system for manipulating and performing calculations on mathematical knots is introduced. Knotica is based on the commercial symbolic algebra system, Mathematica, and can be used to calculate various topological properties of knots, as well as providing a set of ``building-block'' routines that can be incorporated into custom Mathematica-based knot theory programs.