Digital Commons Network^™

An Analysis Of The Paging Activity Of Parallel Programs, Kuei Yu Wang, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

Eppod: A Problem Solving Environment For Parallel Electronic Prototyping Of Physical Object Design, Poting Wu, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Indexing And Distributing A General Patterned Spare Array, Daria Dooling, Lenore Mullin

Computer Science Technical Reports

High performance computing and communication (HPCC) requires that space and time usage are kept to a minimum when solving very large scientific problems. These problems often are represented by sparse systems, and in particular banded systems. In this paper, a new banded array index algorithm is presented that uses substantially less memory than the BLAS (Basic Linear Algebra Subroutines) representation. The algorithm presented here works for multi-dimensional arrays and on all bandwidths. It is visualized as a layer between the applications and the data, thus shielding the caller from the complexities of the sparse representation. Information is returned to the …

Ccsp - A Formal System For Distributed Program Debugging, Beth Arrowsmith, Bruce Mcmillin

Computer Science Technical Reports

One of the major problems with programming in a parallel/distributed environment is the difficulty in debugging the programs due to their complex interactions. One can have results that appear random, but when given a complete knowledge of the specific run-time behavior, the results are foregone. Unfortunately, this complete knowledge is not generally attainable in a distributed system. In order to develop a system for debugging distributed program and, for the more general case, ensuring their correctness at run-time, we built a distributed execution enviromnent based on Hoare's CSP [5] which allows for the execution and evaluation of embedded assertions within …

Parallel Adaptive Mesh Refinement Algorithms, Mustafa Keskin, Fikret Ercal

Computer Science Technical Reports

This study is aimed at developing 2D parallel adaptive mesh refinement algorithms for engineering applications such as penetration mechanics, manufacturing and combustion which use the finite element method for simulation. A new algorithmic approach, called piecewise adaptive mesh refinement for parallelization, is developed and implemented to run on a sequential machine. Performance of the new method is compared against a conventional advancing front technique proposed earlier. A parallel implementation model to run on a massively parallel computer is proposed and its expected efficiency is analyzed theoretically. Furthermore, some issues concerning parallelization and task partitioning are also discussed. In addition, a …

A Deterministic Membership Algorithm In Asynchronous Distributed Systems, P. Su, B. Mcmillin, A. Dekock

Computer Science Technical Reports

This work presents a deterministic asynchronous membership protocol (AMP). Conceptually a membership algorithm provides a means of recruiting members (machines) in a distributed system. Currently most of the research in membership recruiting emphasizes how to obtain the members after a machine fail-stop has occurred during the system operation, and the membership algorithms proposed arc non-deterministic. This work extends the research to develop a deterministic membership algorithm to recruit machines dynamically at the system cold-start. Once it is possible to recruit machines at system cold-start, then it is trivial to recruit members after a machine fail-stop has occurred during the system …

Using Temporal Subsumption To Generate Efficient Error-Detecting Distributed Algorithms, Martina Schollmeyer, Bruce Mcmillin

Computer Science Technical Reports

Distributed algorithms can use executable assertions, which can be derived from program verificatioll or specified in an ad hoc manner, to detect. errors at run-time. However, there may be more assertions available than are really unecessary, and embedding all of them into the program to be checked at run-time would make error-detection very inefficient. For safety-critical systems we often need to make decisions very quickly and cannot allow too much time to be spent on error detection.

The new technique of temporal submission, which is introduced in this dissertation, examines the dependencies between the individual assertions along program execution paths. …

The Formal Description Of Resource Deadlock In Distributed Systems, P. Lu, B. Mcmillin

Computer Science Technical Reports

Deadlock detection is a fundamental problem in a distributed system and has been extensively studied in the past few years. Many distributed deadlock detection/resolution alg·orithms have been proposed, but most of them either have not given a correctness proof or have given an informal proof by using intuitive operational arguments. Informal arguments are prone to errors and many of the published algorithms have been fouud to be incorrect. In trying to avoid this situation, the development of a formal approach to the algorithm correctness proof is required.

In this work, a formal resource deadlock model with global and local clocks …

Hardware Assists For High Performance Computing Using A Mathematics Of Arrays, H. Pottinger, W. Eatherton, L. Mullin, T. Schiefelbein

Computer Science Technical Reports

Work in progress at the University of Missouri - Rolla on hardware assists for high performance computing and communication is presented. This research consists of a field programmable gate array based rapid prototyping environment (Chameleon) being used to evaluate hardware architectures for speedup of array partitioning and routing algorithms. These algorithms have been developed using a Mathematics of Arrays (MOA) and are optimal in the sense that they reduce normal array indexing operations to a series of primitive additions based on array shape. The method is simple yet powerful, produces algorithms which are provably correct, and are independent of dimensionality. …

Parallel Exact Enumeration Of Self-Avoiding Walk On Cubic Lattices And Its Applications To Protein Folding Studies, Anek Vorapanya

Theses

Exact enumeration of self-avoiding walk on many lattices have been studied extensively recently. Even a short chain polymer (about 30 monomers) represented as a chain of cubic lattice sites requires a considerable amount of computer time to exhaustively search for all unique conformations. However, self-avoiding walk process can be modified such that it exhibits a high degree of independence among subprocesses. Parallel implementation of such subprocesses can reduce a great amount of enumeration time. Parallel enumeration makes longer chain enumeration possible.

Enumerating only unique conformations requires that all rotation and mirror conformations be removed. An algorithm to avoid generating such …

Extracting Parallelism At Compile-Time Through Dependence Analysis & Cloning Techniques In An Object-Based Paradigm, Binoy Ravindran

Theses

The construct of Abstract Data Type (ADT) modules and Abstract Data Object (ADO) modules supported by most object-based languages are a great source for developing reusable code. To improve the run time performance of such object-based programs, we consider the asynchronous remote procedure call (ARPC) model of parallel execution, in which concurrency is achieved by having the caller and the callee (which are module instances) running on different processors. Frequently, an ADT module is needed simultaneously by other modules, thus causing contention. To resolve this, we clone the module instance in demand and distribute the copies across different processors, so …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 5, May 1994, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A twelve page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Creation And Simulation Of A Model For A Discrete Time Buffer System With Interrupted Poisson Arrivals And Uncorrelated Server Interruptions, Susanne Naegele-Jackson

Masters Theses & Specialist Projects

A mathematical model for a discrete-time buffer system with both arrival and server interruptions is developed. In this model fixed-size packets arrive at the buffer according to a Poisson distribution and are stored there until they can be transmitted over the output channel. Service times are constant and the buffer is assumed to be of infinite size. Both arrival stream as well as the service of the packets are subjected to random interruptions described by Bernoulli processes, where the interruption process of the Poisson input stream is uncorrelated to the interruptions of the output line. Expressions are derived for the …

Multirate Time-Frequency Distributions, John R. O'Hair

Theses and Dissertations

Multirate systems, which find application in the design and analysis of filter banks, are demonstrated to also be useful as a computational paradigm. It is shown that any problem which can be expressed a set of vector-vector, matrix-vector or matrix-matrix operations can be recast using multirate. This means all of numerical linear algebra can be recast using multirate as the underlying computational paradigm. As a non-trivial example, the multirate computational paradigm is applied to the problem of Generalized Discrete Time- Frequency Distributions GDTFD to create a new family of fast algorithms. The first of this new class of distributions is …

Communication Operations On Coarse-Grained Mesh Architectures, Susanne E. Hambrusch, Farooq Hameed, Ashfaq A. Khokhar

Department of Computer Science Technical Reports

No abstract provided.

Building Information Systems For Mobile Environments, Evaggelia Pitoura, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

The Roles Of Models, Software Tools, And Applications In High Performance Computing, Leah H. Jamieson, Susanne E. Hambrusch, Ashfaq A. Khokhar, Edward J. Delp

Department of Computer Science Technical Reports

No abstract provided.

A Software Platform For Integrating Symbolic Computation With A Pde Solving Environment, Sanjiva Weerawarana, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Load Balancing The Heat Equation In A Heterogeneous Environment With Pvm, N. Nemer-Preece, L. Mullin

Computer Science Technical Reports

Parallel processing is maturing with the ability to program heterogeneous environments and the help of networking systems such as PVM. Heterogeneous multiprocessing has been revolutionized due to tools such as PVM which allows the user to develop code independent of the machine arthitecture. This thesis develops a load balancing algorithm to handle the time march problem, heat conduction. It is based on the speeds of the machines in the current environment.

The heat equation algorithm is enhanced by the Psi Calculus of a Mathematics of Arrays. \l' Calculus allows the indexing of the heat matrix in terms of starts, stops …

Providing Assurance For Reponsive Computing Systems, G. Tsai, B. Mcmillin

Computer Science Technical Reports

A responsive computing system is a hybrid of real-time, distributed and fault-tolerant systems. In such a system, severe consequences will occur if the logical and physical specifications of the system are not met. In this dissertation, an approach to ensure satisfaction of specifications in the operational environment is presented as follows. First, we specify properties of the system using ITL formulas. Next, we collect, at runtime, events and maintain equivalent event histories to represent system execution. Finally, we apply a decision procedure to determine satisfaction of the formulas. A run-time evaluation system was built according to this approach and we …

The Myriad Federated Database Prototype, San-Yih Hwang, Ee Peng Lim, H. R. Yang, S. Musukula, K. Mediratta, M. Ganesh, D. Clements, J. Stenoien, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

Myriad is a federated database system (FDBS) prototype being developed at the University of Minnesota. The main objective behind this prototyping effort is to provide "enterprise-wide" information by integrating independently developed databases while preserving the local autonomy of the component DBMSs and applications. In Myriad, multiple federations can be formed. A federation consists of an integrated database whose schema is represented as a set of integrated relations derived from the export relations provided by the component DBMSS. SQL, mainly due to its simplicity and popularity among database users and vendors, has been adopted to express global queries as well as …

A User-Level Process Package For Concurrent Computing, Ravi Konuru, Steve Otto, Jonathan Walpole, Robert Prouty, Jeremy Casas

Computer Science Faculty Publications and Presentations

A lightweight user-level process(ULP) package for parallel computing is described. Each ULP has its own register context, stack, data and heap space and communication with other ULPs is performed using locally synchronous, location transparent, message passing primitives. The aim of the package is to provide support for lightweight over-decomposition, optimized local communication and transparent dynamic migration. The package supports a subset of the Parallel Virtual Machine(PVM) interface[Sun90).

Knowledge-Based Nonuniform Crossover, Harpal Maini, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

We present a new "knowledge-based non-uniform crossover" (KNUX) operator for genetic algorithms (GA's) that generalizes uniform crossover. We extend this to "Dynamic KNUX" (DKNUX), which constantly updates the knowledge extracted so far from the environment's feedback on previously generated chromosomes. KNUX can improve on good solutions previously obtained by using other algorithms. The modifications made by KNUX are orthogonal to other changes in parameters of GA's, and can be pursued together with any other proposed improvements. Whereas most genetic search methods focus on improving the move-selection procedures, after having chosen a fixed move-generation mechanism, KNUX and DKNUX make the move-generation …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 10, Number 4, April 1994, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Global Picture Archiving And Communication Systems (Gpacs): An Overview, Russell C. Ellis

Theses and Dissertations

The world is currently experiencing a computer revolution. With the expansion and development of new computer technology, the age of video is upon us. The medical world is also currently undergoing a dramatic change. With the development and perfection of non-invasive techniques of probing the body, large amounts of computer data is collected and much of it is used to generate images. The organization and management of these images is the topic of this thesis. The discussion of storage schemes, databases, communications and data compression techniques gives the reader a background and some insight to the current state of the …

Maintaining Consistency Of Data In Mobile Distributed Environments, Evaggelia Pitoura, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

Tcp Buffering And Performance Over An Atm Network, Douglas E. Comer, John C. Lin

Department of Computer Science Technical Reports

No abstract provided.

Countering Abuse Of Name-Based Authentication, Christoph L. Schuba, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

Supporting Complex Data Types In A Relational Distributed Database System, Bharat Bhargava, Yin-He Jiang

Department of Computer Science Technical Reports

No abstract provided.

Dynamic Task Scheduling For The Atamm Multicomputer Operating System Using Embedded Firmware On Microcontrollers, Sudhir Sastry

Electrical & Computer Engineering Theses & Dissertations

A dynamic task scheduling strategy for the distributed processing of large grain dataflow algorithms using embedded firmware on an ATAMM testbed consisting of interconnected microcontrollers is presented in this thesis. The ODU/NASA developed Algorithm to Architecture Mapping Model, ATAMM, uses marked graph models to specify data and control flow for the execution of iterative, deterministic large grain dataflow algorithms in a multicomputing environment. The testbed consists of a bank of four 68HC11 microcontrollers that communicate over a token bus. The token bus arbitration scheme used is contention free and well suited for real-time computing applications. The execution of data flow …