Digital Commons Network^™

Logical Inference Of Horn Clauses In Petri Net Models, C. Lin, A. Chaudhury, A. B. Whinston, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

A Framework For Intelligent Parallel Compilers, Ko-Yang Want

Department of Computer Science Technical Reports

No abstract provided.

On The Impossibility Of Atomic Commitment In Multidatabase Systems, James G. Mullen, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.

Preventing Weak Password Choices, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

Prefetching And Caching Techniques In File Systems For Mimd Multiprocessors, David F. Kotz

Dartmouth Scholarship

The increasing speed of the most powerful computers, especially multiprocessors, makes it difficult to provide sufficient I/O bandwidth to keep them running at full speed for the largest problems. Trends show that the difference in the speed of disk hardware and the speed of processors is increasing, with I/O severely limiting the performance of otherwise fast machines. This widening access-time gap is known as the “I/O bottleneck crisis.” One solution to the crisis, suggested by many researchers, is to use many disks in parallel to increase the overall bandwidth. \par This dissertation studies some of the file system issues needed …

An Evolutionary Approach To Load Balancing Parallel Computations, N. Mansouri, Geoffrey C. Fox

Electrical Engineering and Computer Science - Technical Reports

We present a new approach to balancing the workload in a multicomputer when the problem is decomposed into subproblems mapped to the processors. It is based on a hybrid genetic algorithm. A number of design choices for genetic algorithms are combined in order to ameliorate the problem of premature convergence that is often encountered in the implementation of classical genetic algorithms. The algorithm is hybridized by including a hill climbing procedure which significantly improves the efficiency of the evolution. Moreover, it makes use of problem specific information to evade some computational costs and to reinforce favorable aspects of the genetic …

Prediction Criteria For Successful Weaning From Respiratory Support: Statistical And Connectionist Analyses, K. Ashutosh, Hyungkeun Lee, Chilukuri K. Mohan, Sanjay Ranka, Kishan Mehrotra, C. Alexander

Electrical Engineering and Computer Science - Technical Reports

Objective: To develop predictive criteria for successful weaning from mechanical assistance to ventilation based upon simple clinical tests using discriminant analyses and neural network systems. Design: Retrospective development of predictive criteria and subsequent prospective testing of the same. Setting: Medical intensive care unit of a 300-bed teaching veterans administration hospital. Patients: Twenty-five ventilator-dependent elderly patients with acute respiratory failure. Interventions: Routine measurements of negative inspiratory force (NIF), tidal values (VT), minute ventilation (VE), respiratory rate (RR), vital capacity (FVC), and maximum voluntary ventilation (MVV), followed by weaning trial. Success or failure in 21 efforts analyzed by linear and quadratic discriminant …

Vehicle Routing Using The Sweep Algorithm In Parallel, Jana G. Beattie, Carol L. Spelman

Opportunities for Undergraduate Research Experience Program (OURE)

This paper presents a parallel version of the Sweep Algorithm, a heuristic solution to the smgle-termma] vehicle routing problem The Sweep Algorithm uses a duster-first route-second approach in finding a near-optimal set of routes. The clusters of delivery points are formed by using the terminal as the center and moving around it m a sweeping fashion After a duster is defined, the route is found with a traveling salesperson algorithm.

The parallel version begins the sweep at different angles and performs both forward and backward sweeps. Each node handles a sweep and returns information concerning total distance traveled to the …

The Architecture Of Braid: A System For Bridging Al/Db Systems, Amit P. Sheth, Anthony B. O'Hare

Kno.e.sis Publications

We describe the design of BrAID (a Bridge between Artificial Intelligence and Database Management Systems), an experimental system for the efficient integration of logic based Artificial Intelligence (Al) and database (DB) technologies. Features provided by BrAID include (a) access to conventional DBMSs, (b) support for multiple inferencing strategies, (c) a powerful caching subsystem that manages views and employs subsumption to facilitate the reuse of previously cached data, (d) lazy or eager evaluation of queries submitted by the AI system, and (e) the generation of advice by the AI system to aid in cache management and query execution planning. To discuss …

Simulated Annealing On The Composite Graph Coloring Problem, Kevin Alons

Opportunities for Undergraduate Research Experience Program (OURE)

The composite graph is a finite undirected graph G with no loops and no multiple edges and with positive integers associated with each vertex of G. The number of integers associated with each vertex is the chromaticity of the vertex. The chromatic degree of a vertex v is the sum of the chromaticity of v and the chromaticities of all vertices adjacent to v. The graph G is a v-composite graph if the chromaticities are not equal.

The Traveling Salesman Problem A Parallel Branch And Bound Solution, Tracy Orton, Lan Tran

Opportunities for Undergraduate Research Experience Program (OURE)

A book published in Germany in 1852 said of the successful traveling salesman: "The most important aspect is to cover as many locations as possible without visiting the same location twice." This quote is the earliest mention of the "Traveling Salesman Problem" (TSP). There are many algorithms to solve the TSP, the one we implemented was the Branch and Bound algorithm. The TSP graph G is completely connected by a set of edges E, with a non-negative cost C_ij associated with each edge. A tour of the graph is a cycle containing all vertices once and only once, starting …

An Overview And Evaluation: Computer Software To Aid Students In Prewriting, Writing, And Revision, Mary Lou Shomaker

Opportunities for Undergraduate Research Experience Program (OURE)

The research on computer software to aid inexperienced writers was done from May, 1990 through August, 1990, and involved examining software that would help students improve their writing. The softwares also were evaluated according to their value for use in computer assisted writing classes. The project had three objectives: 1) to evaluate software designed to aid the writer in the pre-writing, writing, and revising stages; 2) to identify the components of this type of software; 3) to recommend software for the beginning academic writer.

Computer Visualization Of Irrotational Flow Over Bluff And Streamlined Bodies, Nora Okong' O

Opportunities for Undergraduate Research Experience Program (OURE)

Computer programs were developed to visualize irrotational flow over bluff bodies (circular cylinders and half-bodies) and streamlined bodies (elliptical cylinders and airfoils). The method of superposition of flows was used, with stream functions or complex velocity potentials for fundamental flows being added to obtain the flows over the bodies. For the flow over the circular cylinders, half-bodies and elliptical cylinders, the stream function was calculated directly. The flow over the airfoil was obtained by Joukowski mapping of the imaginary part of the complex velocity potential for flow over a circular cylinder.

The programs developed will be valuable learning tools for …

Computer Modeling Of A Liquid Fuel Spray, Clemin R. Goodin Jr.

Opportunities for Undergraduate Research Experience Program (OURE)

The initial phase of this project involved manipulation of a lengthy FORTRAN computer code named "Kirwan." The code originated from England many years ago and was transferred to UMR by Dr. Drallmeier. Dr. Drallmeier had the code on a series of 5.25 inch floppy diskettes and the objective of the project was to load the code on to the Apollo computer system and be able to use it....The second phase of the project was begun in early November 1990 and is currently ongoing. The objective of this project is to predict "Rosin-Rammler" (RR) distribution equations for a fuel spray, given …

Using Software To Demonstrate Kinematics Of Gear Sets, John F. Hall

Opportunities for Undergraduate Research Experience Program (OURE)

The research was done in the area of developing software which could be used to demonstrate the motion of gears. To demonstrate this motion involved learning about programming using graphics. Engineering skills were used in the programming in various ways. One way was in developing and implementing the equations and theory. The more critical engineering aspect of this project is in determining what is effective in demonstrating the kinematic principles associated with gear sets.

The programs will be a helpful aid in showing students what is happening with the motion of gear sets. Not only will instructors be allowed to …

A Computer Graphics Program For Displaying Water Molecules On A Dn3500 Apollo Workstation, Michael A. Stuller

Opportunities for Undergraduate Research Experience Program (OURE)

A computer graphics program is developed for displaying water molecule configurations on the screen of a DN3500 Apollo workstation. The motivation was to generate a fast display of output from molecular dynamics or Monte Carlo computer simulations. Input to the program consists of a listing of the Cartesian coordinates of the atomic constituents of the molecules. Options in the program include: 1) number of molecules; 2) plot size; 3) atomic radii; 4) superposition of substrate atomic positions; 5) viewing angle; and 6) color-coded and/or numbered atoms. The program is written in Fortran.

Suggestions For Improvements In Current Computer Image Processing Methods In Detection And Quantification Of The Severity Of Atrophic Rhinitis In Pigs, Jimmy Yu

Opportunities for Undergraduate Research Experience Program (OURE)

This paper investigates several techniques to aid in the utilization of computer image processing methods to detect and quantify the severity of atrophic rhinitis in pigs. An algorithm for reducing the complexity of matrix multiplications from O(n³) to O(n^2.81) is explored. A one-pixel-wide edge detection method is also studied. These techniques are considered for improving the accuracy, repeatability, and speed of existing detection and quantification methods.

Ua66/3/2 Computer Science Alumni Newsletter, Vol. 6, Wku Computer Science

WKU Administration Documents

Newsletter created by WKU Computer Science for alumni of the program.

Termination Via Conditional Reductions, Timothy B. Baird, Ralph W. Wilkerson

Computer Science Faculty Research & Creative Works

We Generalize the Notion of Rewriting Modulo an Equational Theory to Include a Special Form of Conditional Reduction. We Are Able to Show that This Conditional Rewriting Relation Restores the Finite Termination Property Which is Often Lost When Rewriting in the Presence of Infinite Congruence Classes. in Particular, We Are Able to Handle the Class of Collapse Equational Theories Which Contain Associative, Commutative, and Identity Laws for One or More Operators.

Performance Prediction For Distributed Load Balancing In Multicomputer Systems, Ishfaq Ahmad, Arif Ghafoor, Kishan Mehrotra

Electrical Engineering and Computer Science - Technical Reports

Computing literature has being flooded recently with a plethora of dynamic load balancing strategies for multicomputer systems. The diversity of many strategies and their dependence on a number of parameters has made it difficult to compare their effectiveness on a unified basis. Not only does each strategy consider a different environment, but the simplified assumptions obscure the relative merits and demerits of each strategy. This paper presents a solution to compare different load balancing schemes on a unified basis. Our approach, which is an integration of simulation, statistical and analytical experiments, takes into account the fundamental system parameters that can …

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

On Serializability Of Multidatabase Transactions Through Forced Local Conflict, Dimitrios Georgakopoulos, Marek Rusinkiewicz, Amit P. Sheth

Kno.e.sis Publications

The main difficulty in enforcing global serializability in a multidatabase environment lies in resolving indirect transitive conflicts between multidatabase transactions. Indirect conflicts introduced by local transactions are difficult to resolve because the behavior or even the existence of local transactions is not known to the multidatabase system. To overcome these problems, we propose to incorporate additional data manipulation operations in the subtransactions of each multidatabase transaction. We show that if these operations create direct conflicts between subtransactions at each participating local database system, indirect conflicts can be resolved even if the multidatabase system is not aware of their existence. Based …

Effectiveness Analysis Of Knowledge Bases, Shensheng Zhao

Computer Science Theses & Dissertations

Knowledge base systems (expert systems) are entering a critical stage as interest spreads from university research to practical applications. If knowledge base systems are to withstand this transition, special attention must be paid to checking their effectiveness. The issue of effectiveness analysis of knowledge base systems has been largely ignored and few works have been published in this field. This dissertation shows how the effectiveness of a knowledge base system can be defined, discussed and analyzed at the knowledge base system level and the knowledge base level. We characterize the effectiveness of a knowledge base system in terms of minimality, …

Kinematic Synthesis Of Deployable-Foldable Truss Structures Using Graph Theory, Dirk B. Warnaar

Mechanical & Aerospace Engineering Theses & Dissertations

A graph theoretic approach is applied to the conceptual design of deployable truss structures. The characteristics that relate to the inter-connectivity of the elements of a deployable truss structure can be captured in a schematic representation, called a graph. A procedure is presented that enables the exhaustive generation of these graphs for structures of any given number of nodes and links and which are foldable onto a plane or onto a line.

A special type of truss structures, called truss modules, is presented. Graphs of this class of structures form a subset of the graphs of truss structures. Two procedures …

Simulator For Concurrent Processing Data Flow Architectures, Mahyar R. Malekpour

Electrical & Computer Engineering Theses & Dissertations

A software simulator capable of simulating execution of an algorithm graph on a given system under the Algorithm To Architecture Mapping Model (ATAMM) rules is presented in this thesis. ATAMM is capable of modeling the execution of large-grained algorithms on distributed data flow architectures. Investigating the behavior and determining the performance of an ATAMM based system requires the aid of software tools. The ATAMM Simulator presented in this thesis is capable of determining the behavior, performance, and reliability of a system without having to build a hardware prototype. Case studies are performed on four algorithms to demonstrate the capabilities of …

An Efficient Semantic Query Optimization Algorithm, Hwee Hwa Pang, Hongjun Lu, Beng Chin Lu

Research Collection School Of Computing and Information Systems

An efficient semantic query optimization algorithm is proposed, in which all possible transformations are tentatively applied to the query. Instead of physically modifying the query, the transformation process classifies the predicates into imperative, optional or redundant. At the end of the transformation process, all the imperative predicates are retained while the redundant predicates are eliminated. Optional predicates are retrained or discarded based on the estimated cost/benefit of retaining them. The issue of the grouping of semantic constraints to reduce the overhead of retrieving constraints and checking whether each constraint is relevant to the current query is also addressed. Based on …

Computer Use In The Scientific Office, Douglas L. Miller

Psychology Theses & Dissertations

Over the past two decades computers in research and development organizations have become a complex and integral part of the work process. Yet to date only a handful of systematic investigations have addressed issues involving scientists' or other professionals' use of computers, and very little is known about factors influencing use (Bikson and Gutek, 1983; Blacker and Brown, 1986; Collopy, 1988; Gasser, 1986; Helander, 1985; Nickolson, 1985; Pope, 1985). As a result, this research was designed to address four objectives. The first was to develop and evaluate a descriptive model of variables influencing scientists' computer use. The second objective was …

Determining Maximum K-Width-Connectivity On Meshes, Susanne E. Hambrusch, Frank Dehne

Department of Computer Science Technical Reports

No abstract provided.

A Parallel Algorithm For Computing Invariants Of Petri Net Models, Dan C. Marinescu, Mike Beaven, Ryan Stansifer

Department of Computer Science Technical Reports

No abstract provided.

A Purdue University Course In The History Of Computing, Saul Rosen

Department of Computer Science Technical Reports

No abstract provided.