Physical Sciences and Mathematics Commons^™

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

Type 3 Diminimal Maps On The Torus, Adrian Riskin

Mathematics

A polyhedral map on the torus is diminimal if either shrinking or removing an edge yields a nonpolyhedral map. We show that all such maps on the torus fall into one of two classes, type 2 and type 3, and show that there are exactly two type 3 ones, which are given explicitly.

A Software World, David Morgan Lochhead

Dr. David Morgan Lochhead

What are the consequences when software defines reality? This essay was prepared for presentation at a church related computer event in 1991, but was never presented after the event was cancelled

Characterization Of Sh Groups In Porin Of Bovine Heart Mitochondria. Porin Cysteines Are Localized In The Channel Walls., Philadelphia University

Philadelphia University, Jordan

No abstract provided.

Three--Dimensional Medical Imaging: Algorithms And Computer Systems, M. R. Stytz, G. Frieder, O. Frieder

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

This paper presents an introduction to the field of three-dimensional medical imaging It presents medical imaging terms and concepts, summarizes the basic operations performed in three-dimensional medical imaging, and describes sample algorithms for accomplishing these operations. The paper contains a synopsis of the architectures and algorithms used in eight machines to render three-dimensional medical images, with particular emphasis paid to their distinctive contributions. It compares the performance of the machines along several dimensions, including image resolution, elapsed time to form an image, imaging algorithms used in the machine, and the degree of parallelism used in the architecture. The paper concludes …

Performance Prediction For Distributed Load Balancing On Multicomputer Systems, Ishfaq Ahmed, Arif Ghafoor, Kishan Mehrotra

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

This paper presents a performance evaluation approach to compare different distributed load balancing schemes on a unified basis. This approach is an integration of simulation, statistical and analytical models, and takes into account the fundamental system parameters that can possibly affect the performance. We show that all the sender-initiated distributed load balancing strategies can be modeled by a central server open queuing network. Furthermore, these load balancing strategies can be characterized by only two queuing parameters – the average execution queue length and the probability that a newly arrived task is executed locally or migrated to another node. To capture …

Analyzing Images Containing Multiple Sparse Patterns With Neural Networks, Rangachari Anand, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

We have addressed the problem of analyzing images containing multiple sparse overlapped patterns. This problem arises naturally when analyzing the composition of organic macromolecules using data gathered from their NMR spectra. Using a neural network approach, we have obtained excellent results in using NMR data to analyze the presence of various amino acids in protein molecules. We have achieved high correct classification percentages (about 87%) for images containing as many as five substantially distorted overlapping patterns.

Scatter Scheduling For Problems With Unpredictable Structures, Min-You Wu, Wei Shu

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

An extended scatter scheduling was applied to problems with unpredictable, asynchronous structures. It has been found that with this simple scheduling strategy, good load balance can be reached without incurring much runtime overhead. This scheduling algorithm has been implemented on hypercube machines, and its performance is compared with other scheduling strategies.

A Decentralized Task Scheduling Algorithm And Its Performance Modeling For Computer Networks, Ishfaq Ahmad, Arif Ghafoor, Kishan Mehrotra

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

A dynamic task scheduling algorithm, that is stable, de-centralized, and adaptive to network topology, is presented. The proposed algorithm is an extension of nearest neighbor load balancing strategy with an enhanced degree of efficiency and it is intended for multicomputers connected by a store and forward communication network. The proposed algorithm is modeled by a central server open queuing network. It is shown that the response time of a task consists of two parts. The first part comprises a task‘s settling time which consists of scheduling time, communication time, and waiting time in scheduling and communication queues. The second part …

Average Dependence And Random Oracles (Preliminary Report), Stuart A. Kurtz, Stephen R. Mahaney, James S. Royer

Electrical Engineering and Computer Science - Technical Reports

This paper is a technical investigation of issues in computational complexity theory relative to a random oracle. We introduce “average dependence,” an alternative method to Bennett and Gill’s “measure preserving map" technique and illustrate our technique by the following results.

Optimal Parallel Lexicographic Sorting Using A Fine-Grained Decomposition, Ramachandran Vaidyanathan, Carlos R.P. Hartmann, Pramod Varshney

Electrical Engineering and Computer Science - Technical Reports

Though non-comparison based sorting techniques like radix sorting can be done with less "work" than conventional comparison-based methods, they are not used for long keys. This is because even though parallel radix sorting algorithms process the keys in parallel, the symbols in the keys are processed sequentially. In this report, we give an optimal algorithm for lexicographic sorting that can be used to sort n m-bit keys on an EREW model in Ө (log nlogm) time with Ө (mn) "work". This algorithm is not only as fast as any optimal non-comparison based algorithm, but can also be executed with less …

Optimal Processor Assignment For Pipeline Computations, David Nicol, Rahul Simha, Alok N. Choudhury, Bhagirath Narahari

Electrical Engineering and Computer Science - All Scholarship

The availability of large-scale multitasked parallel architectures introduces the following processor assignment problem for pipelined computations. Given a set of tasks and their precedence constraints, along with their experimentally determined individual response times for different processor sizes, find an assignment of processors to tasks. Two objectives interest us: minimal response given a throughput requirement, and maximal throughput given a response time requirement. These assignment problems differ considerably from the classical mapping problem in which several tasks share a processor; instead, we assume that a large number of processors are to be assigned to a relatively small number of tasks. In …

On Minimizing Hardware Overhead For Exhaustive Circuit Testability, Dimitrios Kagaris, Fillia Makedon, Spyros Tragoudas

Computer Science Technical Reports

Exhaustive built-in self testing is given much attention as a viable technique in the context of VLSI technology. In this paper, we present heuristic in order to make exhaustive testing of combinational circuits practical. The goal is to place a small number of register cells on the nets of the input circuit so that the input dependency of combinational elements in the circuit is less than a small given integer k. Our heuristic guarantees that each output can be individually tested with 2k test patterns and can be used as a subroutine to generat efficient test patterns to test all …

A Metric Towards Efficient Exhaustive Test Pattern Generation, Dimitrios Kagaris, Fillia Makedon, Spyros Tragoudas

Computer Science Technical Reports

A viable technique [7] in built-in self-test (BIST)[2] is to generate test patterns pseudo-exhaustively by using linear feedback shift registers (LFSR's). The goal is to find an appropriate primitive polynomial of degree d that will generat 2d test patterns in order to exercise all circuit outputs simultaneously. In an attempt to reduce the degree d of the polynomial the following strategy was proposed in [6,5]. In the first phase, partition the circuit into segments by inserting a small number of register cells, so that the input dependency of any circuit element in the segments is no more than d. Then, …

Implementation Notes On Bdes(1), Matt Bishop

Computer Science Technical Reports

This note describes the implementation of bdes, the file encryption program being distributed in the 4.4 release of the Berkeley Software Distribution. It implements all modes of the Data Encryption Standard program.

An Overview Of Computer Viruses In A Research Environment, Matt Bishop

Computer Science Technical Reports

The threat of attack by computer viruses is in reality a very small part of a much more general threat, specifically attacks aimed at subverting computer security. This paper examines computer viruses as malicious logic in a research and development environment, relates them to various models of security and integrity, and examines current research techniques aimed at controlling the threats viruses in particular, and malicious logic in gerneral, pose to computer systems. Finally, a brief examination of the vulnerabilities of research and development systems that malicious logic and computer viruses may exploit is undertaken.

Privacy-Enhanced Electronic Mail, Matt Bishop

Computer Science Technical Reports

The security of electronic mail sent through the Internet may be described in exactly three words: there is none. The Privacy and Security Research Group has recommended implementing mechanisms designed to provide security enhancements. The first set of mechanisms provides a protocol to provide privacy, integrity, and authentication for electronic mail; the second provides a certificate-based key management infrastructure to support key distribution throughout the internet, to support the first set of mechanisms. This paper describes these mechanisms, as well as the reasons behind their selection and how these mechanisms can be used to provide some measure of securtiy in …

Optimal Parallel And Sequential Algorithms For The Vertex Updating Problem Of A Minimum Spanning Tree, Donald B. Johnson, Panagiotis Metaxas

Computer Science Technical Reports

We present a set of rules that can be used to give optimal solutions to the vertex updating problem for a minimum spanning tree: Update a given MST when a new vertex z is introducted, along with weighted edges that connect z with the vertices of the graph. These rules lead to simple parallel algorithms that run in O(lg n) parallel time using n/lg n EREW PRAMs. They can also be used to derive simple linear-time sequential algorithms for the same problem. Furthermore, we show how our solution can be used to solve the multiple vertex updating problem.

A Parallel Algorithm For The Minimum Spanning Tree, Donald B. Johnson, Panagiotis Metaxas

Computer Science Technical Reports

No abstract provided.

Reducing Computational Expense Of Ray-Tracing Using Surface Oriented Pre-Computation, Robert E. Rinker

UNF Graduate Theses and Dissertations

The technique of rendering a scene using the method of ray-tracing is known to produce excellent graphic quality, but is also generally computationally expensive. Most of this computation involves determining intersections between objects in the scene and ray projections. Previous work to reduce this expense has been directed towards ray oriented optimization techniques. This paper presents a different approach, one that bases pre-computation on the characteristics of the scene itself, making the results independent of the position of the observer. This means that the results of one pre-computation run can be applied to renderings of the scene from multiple view …

Three Denerations Of Dbms, Maria Skiba

Theses : Honours

This paper describes the evolution of data base technology from early computing to the sophisticated systems of today. It presents an overview of the most popular data base management systems architectures such as hierarchical, network, relational and object-oriented. The last section of this paper presents a view of the factors that will influence the future of data base technology.

Transforming A Rule-Based Program, Rose F. Gamble

All Computer Science and Engineering Research

Conflict resolution is a form of global control used in production systems to achieve an efficient sequential execution of a rule-based program. This type of control is not used to parallel production system models [6,13]. Instead, only those programs that make no assumptions regarding conflict resolution are executed in parallel. Therefore, the initial sequential rule-based programs are either executed in parallel without their conflict resolution strategy, which normally results in incorrect behavior, or the programs are transformed in an ad hoc manner to execute on an particular parallel production system model. As a result, these programs do not exhibit the …

Design For Testability And Test Generation With Two Clocks, Vishwani D. Agrawal, Sharad C. Seth, Jitender S. Deogun

CSE Conference and Workshop Papers

We propose a novel design for testability method that enhances the controllability of storage elements by use of additional clock lines Our scheme is applicable to synchronous circuits but is otherwise transparent to the designer. The associated area and speed penalties are minimal compared to scan based methods, however, a sequential ATPG system is necessary for test generation. The basic idea Is to use independent clock lines to control disjoint groups of flip-flops. No cyclic path are permitted among the flip-flops of the same group. During testing, a selected group can be made to hold its state by disabling its …

Disjoint Covers In Replicated Heterogeneous Arrays, P.K. Mckinley, N. Hasan, Ran Libeskind-Hadas, C.L. Liu

All HMC Faculty Publications and Research

Reconfigurable chips are fabricated with redundant elements that can be used to replace the faulty elements. The fault cover problem consists of finding an assignment of redundant elements to the faulty elements such that all of the faults are repaired. In reconfigurable chips that consist of arrays of elements, redundant elements are configured as spare rows and spare columns.

This paper considers the problem in which a chip contains several replicates of a heterogeneous array, one or more sets of spare rows, and one or more sets of spare columns. Each set of spare rows is identical to the set …

Selection Networks, Nicholas Pippenger

All HMC Faculty Publications and Research

An upper bound asymptotic to $2n\log _e n$ is established for the number of comparators required in a network that classifies $n$ values into two classes, each containing $n / 2$ values, with each value in one class less than or equal to each value in the other. (The best lower bound known for this problem is asymptotic to $(n / 2)\log _2 n$.)

Simulating Adaptive Load Sharing Policies On An Ipsc/2 Multicomputer, Yuh Jong Hu, Billy E. Gillett

Computer Science Faculty Research & Creative Works

Unlike most other adaptive load sharing (LS) policy studies, each node in the distributed system is modeled as a central server model represented by a closed queueing network (QN). The primary objective of this study is to use a simulation model to find the improvement for an adaptive LS policy in a distributed system. In homogeneous distributed systems, the simulation results in this study show that the performance improvements between no LS, LS with task placement, and LS with task migration are very small. These results are quite different from other studies, which show a significant improvement of mean response …

Functional Reasoning And Functional Modelling, J. Sticklen, William E. Bond

Computer Science Faculty Research & Creative Works

A car that will not start on a cold winter day and one that will not start on a hot summer day usually indicate two very different situations. When pressed to explain the difference, we would give a winter account- "Oil is more viscous in cold conditions, and that causes . . .'' -and a summer story- "Vapor lock is a possibility in hot weather and is usually caused by . . .'' How do we build such explanations? One possibility is that understanding how the car works as a device gives us a basis for generating the explanations. But …

Actuarial Computation Of Multiemployer Pension Plan Withdrawal Liability, Kelly A. Renze

Presidential Scholars Theses (1990 – 2006)

This project helps to demonstrate how pension actuaries must keep a constant eye on new laws. The pension industry is constantly bombarded with new laws which force them to alter policies and procedures. Because of the huge number of laws, it is difficult for all employees to fully understand every law. During my stay at the Principal, I discovered that many passages are interpreted differently by different people. I also uncovered some details through my research that other employees were not aware of.

Because of this complexity, it is often necessary to assign to one person, such as myself, the …

Graduate Bulletin, 1991-1993, Moorhead State University

Graduate Bulletins (Catalogs)

No abstract provided.

Intelligent Structural Operators For The K-Way Graph Partitioning Problem, Gregor Von Laszewski

Northeast Parallel Architecture Center

A parallel genetic algorithm for the graph partitioning problem is presented, which combines general heuristic algorithms with techniques that are described in evolution theory. In the parallel genetic algorithm the selection of a mate is restricted to a local neighborhood. In addition, the parallel genetic algorithm executes an adaptation step after an individual is generated, with the genetic operators crossover and mutation. During the adaptation step the solution is improved by a common algorithm. Another selection step decides if the adapted descendant should replace the parent individual. Instead of using a uniform crossover operator a more intelligent crossover operator, which …