Digital Commons Network^™

Structured And Object-Oriented Methodologies: A Comparative Analysis Based On A Case Study, Gary Brian Warren

Honors Capstone Projects and Theses

No abstract provided.

Hybrid Arq Schemes For Point-To-Multipoint Communications Over Nonstationary Broadcast Channels, Robert H. Deng

Research Collection School Of Computing and Information Systems

Hybrid automatic-repeat-request (ARQ) error control schemes make use of both error detection and error correction in order to achieve high throughput and low undetected error probabilities on two way channels. Two hybrid ARQ schemes, termed hybrid go-back-N (HGB- N) and hybrid selective-repeat (HSR), are proposed for point-to-multipoint communications over broadcast channels. Both schemes incorporate a concatenated code for error correction and error detection. The performance study of the hybrid schemes is based on a two-state Markov model of a burst noise channel. An analytic solution is derived for the throughput efficiency of the HSR scheme, while approximations and computer simulation …

Implicit Methods On Parallel Processors, Larry Reeves

Computer Science Technical Reports

Since most partial differential equations (PDEs) do not have exact solutions, they are usually solved by some type of numerical method. Since a numerical method is commonly built from finite difference approximations derived from Taylor series expansions, such a development is derived. Stability and convergence of these methods is defined and the rate of convergence is defined and shown for a few simple methods. Of particular importance is the difference between implicit and explicit methods. Finally, the current applications and adaptations of implicit methods on parallel processors are examined and their strengths and weaknesses discussed.

Evaluating The Effectiveness Of Certain Metrics In Measuring The Quality Of End User Documentation, Ronald Morrison

Dissertations and Theses

Traditional methods of evaluating quality in computer end user documentation have been subjective in nature, and have not been widely used in practice. Attempts to quantify quality and more narrowly define the essential features of quality have been limited -- leaving the issue of quality largely up to the writer of the user manual.

Quantifiable measures from the literature, especially Velotta (1992) and Brockman (1990), have been assembled into a set of uniformly weighted metrics for the measurement of document quality. This measure has been applied to the end user documentation of eighty-two personal computer packages. End user documentation is …

Specifying And Enforcing Intertask Dependencies, Paul Attie, Munindar Singh, Amit P. Sheth, Marek Rusinkiewicz

Kno.e.sis Publications

Extensions of the traditional atomic transaction model are needed to support the development of multi-system applications or workflows that access heterogeneous databases and legacy application systems. Most extended transaction models use conditions involving events or dependencies between transactions. Intertask dependencies can serve as a uniform framework for defining extended transaction models. In this paper we introduce event attributes needed to determine whether a dependency is enforceable and to properly schedule events in extended transaction models. Using these attributes and a formalization of a dependency into the temporal logic CTL, we can automatically synthesize an automaton that captures the computations that …

A Survey Of Expert Systems In Singapore And The Integration Of Multimedia Technology And Expert Systems, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

Expert systems technologies have been widely adopted by different industries form the early 1980s. There have been examples of expert systems embedded in applications developed for the financial and banking sector, manufacturing, services and government. In section 2 of this paper, we present a scan of expert systems used in different sectors. Section 3 will cover the expert system tools and applications developed in the decade of the 1980s. Section 4 will present some of the ongoing expert systems related activities. Section 5 will extrapolate the present work to forecast the future types of expert systems that might be developed …

Global Committability In Multidatabase Systems, O. Bukhres, Ahmed K. Elmagarmid, J. Jing, W. Kim, A. Zhang

Department of Computer Science Technical Reports

No abstract provided.

Optimizing Communication Routing In Parallel Computer Architectures, Nikolaos T. Liolios

Masters Theses

This thesis is a research effort to improve on existing algorithms for processor placement and routing on hypercube and 2d-transputer parallel architectures that perform communications through message propagation. Given a set of processors N, randomly distributed on the parallel computer network, the problem is to find an optimal communication routing that minimizes the number of required links and intermediate processors. It was concluded that the spanning tree is the best starting heuristic for the routing problem. For hypercubes an algorithm was developed that outperforms all algorithms in the literature. For 2d-transputers the method of overlap maximization used in VLSI routing, …

Performance Analysis Of Two Bridged Csma/Cd Networks, C. C. Ko, W. C. Wang, J. L. Du, Robert H. Deng, K. M. Lye

Research Collection School Of Computing and Information Systems

This paper analyses the performance of two non-persistent CSMA/CD LANs linked by a bridge. The main function of the bridge is to buffer all internet work packets and forward them across networks to their destinations. From establishing and solving the main equations governing the behaviour of the bridged networks, the effects of design parameters such as the bridge buffer size and re-transmission back off delay on the performance of the system are studied. It is shown that if these parameters are chosen properly, better throughput and delay performance can be obtained, when compared with an equivalent CSMA/CD network without using …

Genetic Algorithm With 3-Parent Uniform Crossover, L. Vincent Edmondson, Billy E. Gillett

Computer Science Technical Reports

A new genetic algorithm which uses a 3-parent uniform crossover operator is developed and analyzed. Uniform crossover operators are shown to be based on the premise that all bit-level genetic information should be passed from parents to children. The 3-parent uniform crossover operator is shown to adhere to this premise. The 3-parent uniform crossover operator is shown to be better than the 2-parent uniform crossover operator on the De Jong test functions.

Two new genetic algorithms which use 3-parent traditional crossover operators are developed and analyzed. The first uses a strategy of randomly selecting 3 of the 6 children resulting …

On Object Semantic Similarity In Heterogeneous Database Integration, Xiangning Lui, Omran A. Bukhres

Department of Computer Science Technical Reports

No abstract provided.

A Framework For Flexible Transaction Management In Multidatabase Systems, Aidong Zhang, Omran Bukhres, Ahmed Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.

Policy And Procedures Manual: Department Of Computer Sciences, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Performance Of A Token-Passing System With Batch Arrivals And Its Application To File Transfers, Robert H. Deng, Xuanyu Zhang, Kuan Tase Huang

Research Collection School Of Computing and Information Systems

This paper investigates the performance of token-passing systems with limited service and Poisson arrivals. For pure Poisson arrivals, the Laplace-Stieltjes Transform (LST) of an approximate customer/packet waiting time distribution is derived and expressed as a functional equation, from which the approximate mean and variance of waiting time are obtained; for batch Poisson arrivals, an approximate mean of waiting time is derived. Mean waiting time approximations are compared against both simulation results and other results presented in the literature; the variance approximation is evaluated by comparing it to simulation results only, since no other results on variance have been reported so …

Performance Analysis Of Interconnected Lans With Server/Client Configuration, Jiangling Du, Robert H. Deng, Chi Chung Ko

Research Collection School Of Computing and Information Systems

In this paper, we study the end-to-end performance of interconnected local area networks (LAN) with server/client configuration. The system uses bridges to connect two token-ring LANs through a high-speed communication link. A server station located on one LAN receives requests from client-stations on the same LAN as well as on the remote LAN, processes the requests, and returns responses to the client-stations. The end-to-end connections of the interconnected network are modelled as single-chain and multiple-chain closed queueing systems, which are solved by an iterative algorithm based on the MVA (mean value analysis) method. The performance examples are shown in terms …

A General Method For Maximizing The Error-Detecting Ability Of Distributd Algorithms, Martina Schollmeyer, Bruce M. Mcmillin

Computer Science Technical Reports

Error-detecting algorithms can determine when, at run time, a program deviates from its expected behavior due to a hardware, software or communication error. In a fixed interconnect multiprocessor system, the error detecting ability heavily depends on the number of faults, which is bounded, and their spatial distribution. Otherwise multiple fault occurrences can mask each other. This paper provides a general method for computing the overall system failure bound, the maximal fault index, from the system topology and local communication patterns. The result of the computation is used to design a mapping of processes to processor groups such that multiple processor …

Putting Humpty-Dumpty Together Again: Reconstructing Functions From Their Projections., Anil Ravindran Menon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

Electrical Engineering and Computer Science - Technical Reports

We present a problem decomposition approach to reduce neural net training times. The basic idea is to train neural nets in parallel on marginal distributions obtained from the original distribution (via projection), and then reconstruct the original table from the marginals (via a procedure similar to the join operator in database theory). A function is said to be reconstructible, if it may be recovered without error from its projections. Most distributions are non-reconstructible. The main result of this paper is the Reconstruction theorem, which enables non-reconstructible functions to be expressed in terms of reconstructible ones, and thus facilitates the application …

Off-Line Cursive Handwriting Recognition Using Style Parameters, Berrin A. Yanikoglu, Peter A. Sandon

Computer Science Technical Reports

We present a system for recognizing off-line cursive English text, guided in part by global characteristics of the handwriting. A new method for finding the letter boundaries, based on minimizing a heuristic cost function, is introduced. The function is evaluated at each point along the baseline of the word to find the best possible segmentation points. The algorithm tries to find all the actual letter boundaries and as few additional ones as possible. After size and slant normalizations, the segments are classified by a one hidden layer feedforward neural network. The word recognition algorithm finds the segmentation points that are …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 9, Number 6, June 1993, 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.

Feasible Offset And Optimal Offset For Single-Layer Channel Routing, Ronald I. Greenberg, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

The paper provides an efficient method to find all feasible offsets for a given separation in a VLSI channel routing problem in one layer. The prior literature considers this task only for problems with no single-sided nets. When single-sided nets are included, the worst-case solution time increases from Theta(n) to Omega(n^2), where n is the number of nets. But, if the number of columns c is O(n), one can solve the problem in time O(n^{1.5}lg n ), which improves upon a `naive' O(cn) approach. As a corollary of this result, the same time bound suffices to find the optimal offset …

Dmodel And Dalgebra : A Data Model And Algebra For Office Documents, Fortune Solani Mhlanga

Dissertations

This dissertation presents a data model (called D_model) and an algebra (called D_ algebra) for office documents. The data model adopts a very natural view of modeling office documents. Documents are grouped into classes; each class is characterized by a "frame template", which describes the properties (or attributes) for the class of documents. A frame template is instantiated by providing it with values to form a "frame instance" which becomes the synopsis of the document of the class associated with the frame template. Different frame instances can be grouped into a folder. Therefore, a folder is a set of frame …

Megsdf Mega-System Development Framework, Tamar Zemel

Dissertations

A framework for developing large, complex software systems, called Mega-Systems, is specified. The framework incorporates engineering, managerial, and technological aspects of development, concentrating on an engineering process. MegSDF proposes developing Mega-Systems as open distributed systems, pre-planned to be integrated with other systems, and designed for change.

At the management level, MegSDF divides the development of a Mega-System into multiple coordinated projects, distinguishing between a meta-management for the whole development effort, responsible for long-term, global objectives, and local managements for the smaller projects, responsible for local, temporary objectives.

At the engineering level, MegSDF defines a process model which specifies the tasks …

Techniques Of Petri Net Reduction, Sreeranga Kalavapalli

Theses

Petri Nets have the capability to analyze large and complex concurrent systems. However, there is one constraint. The number of reachability states of the concurrent systems outweighs the capability of Petri Nets. Previous Petri Net reduction techniques focussed on reducing a subnet to a single transition and hence not powerful enough to reduce a Petri Net. This paper presents six reduction rules and discusses their drawbacks. A new reduction technique called Knitting Technique to delete paths of a Petri Net while retaining all the properties of the original net is presented. Further Structural matrix which facilitates reduction is presented.

Throughput Of Existing Multiprocessor File Systems (An Informal Study), David Kotz

Computer Science Technical Reports

Fast file systems are critical for high-performance scientific computing, since many scientific applications have tremendous I/O requirements. Many parallel supercomputers have only recently obtained fully parallel I/O architectures and file systems, which are necessary for scalable I/O performance. Scalability aside, I show here that many systems lack sufficient absolute performance. I do this by surveying the performance reported in the literature, summarized in an informal table.

The State Of Computer Science Facilities Of Schools Across The United States That Are Comparable To Illinois Wesleyan University, Sarah A. Bartz '93

Honors Projects

The purpose of this study is to compare Illinois Wesleyan's academic computer facilities with those at other comparable U.S. colleges and universities. This study also investigates factors affecting these facilities such as the methods other institutions use to deal with and plan for the constantly changing computer world. To obtain this information a survey was mailed to over 250 institutions across the U.S. that were considered comparable to IWU. These institutions include the Associated Colleges of the Midwest, the Oberlin Group, and some of the top colleges and universities in the U.S. as ranked in U.S. News and World Report's …

The Design, Analysis, And Implementation Of Parallel Simulated Annealing And Parallel Genetic Algorithms For The Composite Graph Coloring Problem, Brent S. Elmer, Billy E. Gillett

Computer Science Technical Reports

The composite graph coloring problem (CGCP) is similar to the standard graph coloring problem (SGCP). Associated with each vertex of a composite graph is a positive integer which represents the chromaticity of that vertex. This number is the number of consecutive integers (colors) which must be assigned to the vertex. The goal of the CGCP is to color the graph with as few colors as possible. The largest integer used in the coloring is called the chromatic number of the graph. The CGCP is proven to be NP-complete.

Exact, heuristic, and stochastic methods are analyzed and compared. Exact methods are …

The Third International Conference On Expert Systems For Numerical Computing, Elias N. Houstis, John R. Rice, Robert Vichnevetsky

Department of Computer Science Technical Reports

No abstract provided.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 9, Number 4, April 1993, 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.

Parallel Electronic Prototyping Of Physical Objects, Poting Wu, Elias N. Houstis

Department of Computer Science Technical Reports

No abstract provided.

Building A Large Scale Distributed Object System For A Multilingual Programming Environment, Patrick A. Muckelbauer, Vincent F. Russo

Department of Computer Science Technical Reports

No abstract provided.