Digital Commons Network^™

Evolving Globally Synchronized Cellular Automata, Rajarshi Das, James P. Crutchfield, Melanie Mitchell, James M. Hanson

Computer Science Faculty Publications and Presentations

How does an evolutionary process interact with a decentralized, distributed system in order to produce globally coordinated behavior? Using a genetic algorithm (GA) to evolve cellular automata (CAs), we show that the evolution of spontaneous synchronization, one type of emergent coordination, takes advantage of the underlying medium's potential to form embedded particles. The particles, typically phase defects between synchronous regions, are designed by the evolutionary process to resolve frustrations in the global phase. We describe in detail one typical solution discovered by the GA, delineating the discovered synchronization algorithm in terms of embedded particles and their interactions. We also use …

Sciagents--An Agent Based Environment For Distributed, Cooperative Scientific Computing, Tzvetan T. Drashansky, Anupam Joshi, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Exceptions And Exception Handling In Computerized Information Processes, Diane M. Strong, Steven M. Miller

Research Collection School Of Computing and Information Systems

Exceptions, situations that cannot be correctly processed by computer systems, occur frequently in computer-based information processes. Five perspectives on exceptions provide insights into why exceptions occur and how they might be eliminated or more efficiently handled. We investigate these perspectives using an in-depth study of an operating information process that has frequent exceptions. Our results support the use of a total quality management (TQM) approach of eliminating exceptions for some exceptions, in particular, those caused by computer systems that are poor matches to organizational processes. However, some exceptions are explained better by a political system perspective of conflicting goals between …

Knowledge Acquisition And Structuring By Multiple Experts In A Group Support Systems Environment, Bernard Lee Lewis

Engineering Management & Systems Engineering Theses & Dissertations

This study addresses the impact of Group Decision Support Systems (GDSS) on expert system development by multiple Domain Experts. Current approaches to building expert systems rely heavily on knowledge acquisition and prototyping by a Knowledge Engineer working directly with the Domain Expert. Although the complexity of knowledge domains and new organizational approaches demand the involvement of multiple experts, standard procedures limit the ability of the Knowledge Engineer to work with more than one expert at a time.

Group Decision Support Systems offer a networked computerized environment for group work activities, in which multiple experts may express their ideas concurrently and …

Open-Loop State-Space Model Identification From Closed-Loop Data, Lori Guy

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis provides an investigation of a system identification algorithm which identifies an open-loop state-space model from a linear system that is operating under closed-loop conditions. In order to investigate the system identification algorithm some basic ideas of system identification theory are reviewed. Examples using simulated data are presented to characterize the effects of varying the parameters for open-loop and closed-loop system identification processes. Both noise· free and noise contaminated cases are simulated. Linear Quadratic Gaussian (LQG) control theory is reviewed and the motivation for using iterative LQG control feedback is discussed. The derivation of the proposed system identification algorithm …

Mpvm: A Migration Transparent Version Of Pvm, Jeremy Casas, Dan Clark, Ravi Konuru, Steve Otto, Robert Prouty, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Parallel Virtual Machine (PVM) is a widely-used software system that allows a heterogeneous set of parallel and serial UNIX-based computers to be programmed as a single message-passing parallel machine, In this paper, an extension to PVM to support dynamic process migration is presented. Support for migration is important in general-purpose workstation environments since it allows parallel computations to co-exist with other applications, using idle-cycles as they become available and off-loading from workstations when they are no longer free. A description and evaluation of the design and implementation of the prototype Migratable PVM system is presented together with some performance results.

Expanding The Potential For Disk-Directed I/O, David Kotz

Computer Science Technical Reports

As parallel computers are increasingly used to run scientific applications with large data sets, and as processor speeds continue to increase, it becomes more important to provide fast, effective parallel file systems for data storage and for temporary files. In an earlier work we demonstrated that a technique we call disk-directed I/O has the potential to provide consistent high performance for large, collective, structured I/O requests. In this paper we expand on this potential by demonstrating the ability of a disk-directed I/O system to read irregular subsets of data from a file, and to filter and distribute incoming data according …

1.4, Yolanda Jones

E-lert

No abstract provided.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 3, March 1995, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Formal Foundations For The Specification Of Software Architecture, Mark J. Gerken

Theses and Dissertations

This investigation establishes a formal foundation for software architecture that allows for the specification of large, non-trivial software systems using well founded, consistency preserving construction techniques. Two fundamental problems were addressed: how to define and express architectures formally using the concept of theories, and how architecture theories can be practically applied in specification construction. The initial stages of this investigation sought to establish a formal, mathematical relationship between functional specifications of behavior and specifications defining system structure. Experimental results lead to the conclusion that architectures defining the structure of functional operations can be defined using functional logic, but more complex …

To Learn Or Not To Learn ...., Anupam Joshi

Department of Computer Science Technical Reports

No abstract provided.

Characterization Of The Paging Activity Of Nas Benchmark Programs On The Intel Paragon, Kuei Yu Wang, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

On Pattern Occurrences In A Random Text, Ioannis Fudos, Evaggelia Pitoura, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

Display - A Visualization And User Interaction Interface For Parallel Simulation Environments, Edward Mascarenhas, Vernon J. Rego

Department of Computer Science Technical Reports

No abstract provided.

On Asymptotics Of Certain Sums Arising In In Coding Theory, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

Ariadne: Architecture Of A Portable Threads System Supporting Mobile Processes, Edward Mascarenhas, Vernon Rego

Department of Computer Science Technical Reports

No abstract provided.

Classical Ip And Arp Over Atm, Christoph L. Schuba, Berry Kercheval, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

An Efficient And Reliable Reservation Algorithm For Mobile Transactions, Ahmed K. Elmagarmid, Jin Jing, Omran Bukhres

Department of Computer Science Technical Reports

No abstract provided.

Study Of The Subjet Structure Of Quark And Gluon Jets, D. Buskulic, D., M. Thulasidas

Research Collection School Of Computing and Information Systems

Measurements of the subjet structure of quark and gluon jets in hadronic Z decays are presented. The analysis is based on one million hadronic events recorded by the Aleph detector. Roughly symmetric three-jet events are selected with a coarse jet-resolution cut-off, y1. Gluon jets are identified with a purity of 94.6% in those events where evidence of long-lived heavy-flavour hadrons in the other two jets is found. The jets are then analyzed using a smaller cut-off y0 (< y1) so that subjets are resolved. The properties of the jets (subjet multiplicities (Nq), (Ng) and rates Rng(q) for n = 1, 2, 3, 4) are determined and are found to be in good agreement with the expectations of perturbative QCD as long as the subjet resolution parameter y0 is sufficiently large to keep non-perturbative effects small. In particular, the ratio , which to leading order in QCD is given by the ratio of colour factors , is measured to be 1.96 ± 0.15 for y0 = 2 · 10−3, but falls to 1.29 ± 0.03 for y0 = 1.6 · 10−5.

Interview: Joel Slayton, Christine Laffer

SWITCH

Interview with Joel Slayton, Professor of Computers in Fine Art at San José State University, and Director of the CADRE Institute. Slayton discusses the history of the Cadre Institute and details his views on the relationship between art and new technology. Slayton describes the role of artists in exploring the possibilities and ethical implications of emerging technologies such as genetic engineering, nano-techology, robotics, and artificial life. He describes installations and in-progress work focused on ubiquitous video surveillance. The interview concludes with a discussion of Slayton’s use of the DoWhatDo model for artistic collaboration and of his piece "Conduits," presented in …

Exploring The Use Of I/O Nodes For Computation In A Mimd Multiprocessor, David Kotz, Ting Cai

Computer Science Technical Reports

As parallel systems move into the production scientific computing world, the emphasis will be on cost-effective solutions that provide high throughput for a mix of applications. Cost-effective solutions demand that a system make effective use of all of its resources. Many MIMD multiprocessors today, however, distinguish between ``compute'' and ``I/O'' nodes, the latter having attached disks and being dedicated to running the file-system server. This static division of responsibilities simplifies system management but does not necessarily lead to the best performance in workloads that need a different balance of computation and I/O. Of course, computational processes sharing a node with …

Weighted Coverings And Packings, G. D. Cohen, Iiro Honkala, S. N. Litsyn, H. F. Mattson Jr

Electrical Engineering and Computer Science - Technical Reports

In this paper we introduce a generalization of the concepts of coverings and packings in Hamming space called weighted coverings and packings. This allows us to formulate a number of well-known coding theoretical problems in a uniform manner. We study the existence of perfect weighted codes, discuss connections between weighted coverings and packings, and present many constructions for them.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 11, Number 2, February 1995, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Active Defense Of A Computer System Using Autonomous Agents, Mark Crosbie, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

Adapting Distributed Database Systems For High Availability, Xiangning Liu, Evaggelia Pitoura, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

Concurrent And Fail-Safe Replicated Simulations On Heterogeneous Networks: An Introduction To Eclipse, Felipe Knop, Edward Mascarenhas, Vernon J. Rego, V. S. Sunderam

Department of Computer Science Technical Reports

No abstract provided.

A Software Architecture To Support Misuse Intrusion Detection, Sandeep Kumar, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

Parallel Adaptive Mesh Generation And Decomposition, Poting Wu, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.

Consistent And Recoverable Agent-Based Access To Heterogeneous Mobile Databases, Evaggelia Pitoura, Bharat Bhargava

Department of Computer Science Technical Reports

No abstract provided.

A Type I Hybrid Arq System With Adaptive Code Rates, Robert H. Deng, Michael L. Lin

Research Collection School Of Computing and Information Systems

Type I hybrid ARQ systems use an error-control code of fixed rate for error-correction in each transmitted packet. In such systems, the code rate must be carefully chosen to match the channel bit error rate (BER) in order to maximize system throughput. Whenever there is a mismatch between code rate and channel BER, the throughput suffers. In this paper, we proposed a type I hybrid ARQ system which automatically adjusts its code rates to match channel BERs. The proposed system is very simple to implement and yet performs significantly better than type I hybrid ARQ systems of fixed code rate