Digital Commons Network^™

Maintaining Consistency Of Interdependent Data In Multidatabase Systems, Amit P. Sheth, Yungho Leu, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.

Global Commitment In Multidatabase Systems, Ahmed K. Elmagarmid, Jin Jing, Won Kim

Department of Computer Science Technical Reports

No abstract provided.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, March 1991, 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.

A Unified Framework For Three-Valued Semantical Treatments Of Logic Programming, Feng Yang

Electrical Engineering and Computer Science - Technical Reports

Based on Fiting's Φ operator a unified framework for three-valued semantics of logic programming is presented. The truth space used in the framework is the class of partial interpretations. Underlying the truth space is two partial orderings, knowledge ordering and truth ordering. It turns out that the truth space with the truth ordering is a complete lattice and the truth space with knowledge ordering is a semi-complete lattice. Φ is proved to be continuous over the complete lattice and monotonic over the semi-complete lattice. With the use of Φ operator two well-known three-valued semantics for logic programming, Fitting's three-valued semantics …

A Study Of Approximating The Moments Of The Job Completion Time In Pert Networks, Kishan Mehrotra, John Chai, Sharma Pillutla

Electrical Engineering and Computer Science - Technical Reports

The importance of proper management of projects has not gone unrecognized in industry and academia. Consequently tools like Critical Path Method (CPM) and Program Evaluation Review Technique (PERT) for project planning have been the focus of attention of both practitioners and researchers. Determination of the Time to Complete the Job (TCJ) in PERT networks is important for planning and bidding purposes. The complexity involved in accurately determining the TCJ has led to the development of many approximating procedures. Most of them ignore the dependence between paths in the network. We propose an approximation to determine the TCJ which explicitly recognizes …

Transfer Of 4gl Application From Ingres To Oracle, Adnan Altunisik

Theses and Dissertations

This paper documents the transfer of 4GL applications from INGRES to ORACLE. As a result of a fast and conceptual change in computer languages, 4GLs were developed and evolved. These are programming support tools whose goal is, basically, to make the programs more efficient by reducing the number of instructions. Both ORACLE and INGRES database systems use 4GLs to develop applications. Their 4GL environments and their facilities for application development are investigated and explained in depth in this effort. The TWX application, which was originally implemented in INGRES by using its 4GL, is designed and reimplemented in ORACLE. This is …

An Automated Red Player For The Theater Warfare Exercise, Karl W. Kabanek

Theses and Dissertations

The Theater Warfare Exercise (TWX) is a two-sided, theater-level, decision-making exercise created, maintained and used by the personnel at the Air Force Wargaming Center. It is used to allow military officers to practice the decision-making process needed for the wartime employment of air power. An automated player was designed and a prototype implemented for the red (enemy) player using an expert system shell. The automated red player uses the TWX database that contains the data on the different units used in exercise. From the data the automated red player builds mission packages for the various types of missions required in …

Dna Mapping Algorithms: Topological Mapping, Kenneth Moorman, Paul Poulosky, Will Gillett

All Computer Science and Engineering Research

There are several basic approaches that can be used in attempting to produce high-resolution DNA restriction maps. A standard approach is the match/merge approach in which first the topology of the map units being mapped together is suppressed and lists of potential matches between fragments are generated, and second the topology is introduced to eliminate matchlists which are inconsistent with the topology. This technical report documents a different approach to DNA mapping, known as topological mapping. In topological mapping the precedence of the two criteria are reversed, i.e., the topology of the two map units is used as the primary …

Duality In Logic Programming, Feng Yang

Electrical Engineering and Computer Science - Technical Reports

Various approximations of classic negation have been proposed for logic programming. But the semantics for those approximations are not entirely clear. In this paper a proof-theoretic operator, we call it failure operator, denoted as FP, is associated with each logic program to characterize the meaning of various negations in logic programming. It is shown that the failure operator FP is a dual of the TP, immediate consequence operator developed by Van Emden and Kowalski and is downward continuous. It has the desirable properties entirely analogous to what TP has such as continuity, having a unique least fixpoint and a unique …

The N-Body Pipeline, Per Brinch Hansen

Electrical Engineering and Computer Science - Technical Reports

A general pipeline for all-pairs computations is adapted for direct force summation of n bodies which interact through gravitation only. To achieve approximate load balance the pipeline is folded several times across an array of processors. The performance of the pipeline is analyzed and measured on a Computing Surface.

The Boundary Element Method Applied To The Two Dimensional Stefan Moving Boundary Problem, Donald C. Vosika

Theses and Dissertations

This thesis considers problems for which the boundary is not known before the problem is solved and must be determined as part of the solution. We consider a time dependent problem which results in a moving boundary. We look at the heat conduction/diffusion equation in one and two spatial dimensions. We use Green's Theorem to yield a Volterra boundary integral equation which involves an unknown function on the moving boundary. We use the boundary element method to obtain a solution. Graphical results for the two dimensional problem are presented.

A Computer Simulation Of Braitenberg Vehicles, Eric B. Werkowitz

Theses and Dissertations

In his treatise, Vehicles: Experiments in Synthetic Psychology, Valentino Braitenberg used simple, autonomous vehicle designs to illustrate the principles behind animal nervous system organization and operation. The goal of this effort was to produce a computer program to allow a researcher to experiment with these concepts and to analyze their performance using methods employed by experimental psychologists. The resulting program allows the user to design vehicles that respond to changes in their environments and that have the ability to adapt their behavior, using a learning algorithm developed by Teuvo Kohonen. The vehicle designer is free to select sensor attributes, …

Optimal Iterative Task Scheduling For Parallel Simulations, Joann M. Sartor

Theses and Dissertations

The ultimate purpose of this research is to reduce the time needed for execution of parallel computer simulations. In particular, the impact of task assignment strategies is determined for parallel VHDL circuit simulations. The classical scheduling problem, which assigns n precedence-constrained tasks to m processors is NP-complete in all but the simplest cases. The problem of assigning simulation tasks is further complicated by the iterative nature of computer simulations: each task is required to execute multiple times as the simulation executes. This investigation develops a polynomial-time algorithm (the level strategy) which provides optimal assignment for iterative systems with specific constraints. …

Eliminating Extraneous Solutions In Curve And Surface Operations, Christoph M. Hoffmann, Pamela J. Vermeer

Department of Computer Science Technical Reports

No abstract provided.

A Framework For 1-D Compaction With Forbidden Region Avoidance, Susanne E. Hambrusch, Hung-Yi Tu

Department of Computer Science Technical Reports

No abstract provided.

Analyzing Availability Of Replicated Database Systems, Bharat Bhargava, Abdelsalam Helal, Karl Friesen

Department of Computer Science Technical Reports

No abstract provided.

Multisearch Techniques: Parallel Data Structures On Mesh-Connected Computers, Mikhail J. Atallah, Frank Dehne, Russ Miller, Andrew Rau-Chaplin, Jyh-Jong Tsay

Department of Computer Science Technical Reports

No abstract provided.

A Robust Intersection Algorithm Based On Delaunay Triangulation, Kokichi Sugihara

Department of Computer Science Technical Reports

No abstract provided.

Autocorrelation On Words And Its Applications, Philippe Jacquet, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

Efficient Crcw-Pram Algorithms Combining Multiple Autonomous Databases, Alberto Apostolico

Department of Computer Science Technical Reports

No abstract provided.

An Optimal Parallel Algorithm For Detecting Weak Visibility Of A Simple Polygon, Danny Z. Chen

Department of Computer Science Technical Reports

No abstract provided.

Concurrency Control, Version Management And Transactions In Advanced Database Systems, Jonathan Walpole, Muntuck Yap

Computer Science Faculty Publications and Presentations

This document constitutes the final deliverable for the research project titled “An Investigation of Selected Issues in Transaction Mechanism Design for Object Oriented Databases.” The document describes our ideas for extending the traditional transaction concept for use in object oriented databases, and concentrates specifically on providing an underlying model to support the concurrency control and version management aspects of the problem. The ideas presented here are not however restricted to the domain of object oriented databases. They are more generally applicable to database systems that require flexibility in their versioning and concurrency control policies.

In this document we define a …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, February 1991, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Performance Evaluation Of A Traffic Control Mechanism For Atm Networks, Andreas D. Bovopoulos

All Computer Science and Engineering Research

Future ATM networks will be required to support a plethora of services, transaction types and cell sequence behaviors with performance guarantees. Before this goal can be realized, however, some basically problems related to bandwidth allocation and traffic control in the ATM layer must be resolve. Such problems will in all likelihood defy solution as long as they studied in isolation without a unifying traffic characterization and traffic control framework. This work presented in this paper is part of an ongoing effort directed at the development of an integrated traffic characterization and control infrastructure for ATM networks. In this paper a …

Saam: The Strategic Asset Allocation Model, Judy Lewis, Todd Gamble, John Tai

All Computer Science and Engineering Research

Asset Allocation has become a dominant factor for investment strategies in recent years. It has found that by holding a strategically diversified portfolio, a high total return on investments can be maintained while, at the same time, reducing portfolio volatility. With recent federal regulations mandating pension investment responsibilities, appropriate asset allocation has become more important than ever. SAAM is a software package specifically designed to be used as a tool to aid the investment professional in determining pension portfolio allocations. SAAM uses the expect system shell CLIPS, has a user-friendly interface, displays output graphically, and runs within the confines of …

A Practical Hierarchial Model Of Parallel Computation: The Model, Todd Heywood, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

We introduce a model of parallel computation that retains the ideal properties of the PRAM by using it as a sub-model, while simultaneously being more reflective of realistic parallel architectures by accounting for and providing abstract control over communication and synchronization costs. The Hierarchical PRAM (H-PRAM) model controls conceptual complexity in the face of asynchrony in two ways. First, by providing the simplifying assumption of synchronization to the design of algorithms, but allowing the algorithms to work asynchronously with each other; and organizing this "control asynchrony" via an implicit hierarchy relation. Second, by allowing the restriction of "communication asynchrony" in …

Performance Analysis Of The Ethernet Under Conditions Of Bursty Traffic, Tony Y. Mazraani, Gurudatta M. Parulkar

All Computer Science and Engineering Research

In this paper we present a simulation study of the Ethernet performance under conditions of bursty traffic. This study is motivated by two observations: Ethernet will continue to be a widely used Local Area Network (LAN), especially as an access LAN for future high speed internet (or Broadband ISDN); and future high speed applications can best be modeled as bursty sources. Bursty traffic in this study is specified using three parameters: peak bandwidth, average bandwidth, and burst factor. The simulation study shows that the inherent behavior of the Ethernet does not change with bursty traffic. That is, as long as …

Multiple Expert System, Umesh Kumar Mittal

Theses

In many domains, for example medical diagnosis, there are several sources of knowledge, e.g., several domain experts. These domain experts may have disagreements over some issues in the domain. Research in the area of human decision making suggests that a human decision is not always made based on the advice of a single expert. Many current expert systems, however, expect consistency in their knowledge bases. An expert system does not deliberate by reasoning that "on one hand..." but "on the other hand..." The knowledge engineer, who is not necessarily an expert in the same domain, ensures consistency by eliminating all …

Evolution Of A Communication System For Distributed Transaction Processing In Raid, Bharat Bhargava, Yongguang Zhang, Enrique Mafla

Department of Computer Science Technical Reports

No abstract provided.

Mechanical Parts Orienting: The Case Of A Polyhedron On A Table, Michael Erdmann, Matthew T. Mason, George Vanĕček

Department of Computer Science Technical Reports

No abstract provided.