Physical Sciences and Mathematics Commons^™

Data Dependence In Programs Involving Indexed Variables, Borislav Nikolik

Dissertations and Theses

Symbolic execution is a powerful technique used to perform various activities such as program testing, formal verification of programs, etc. However, symbolic execution does not deal with indexed variables in an adequate manner. Integration of indexed variables such as arrays into symbolic execution would increase the generality of this technique. We present an original substitution technique that produces array-term-free constraints as a counterargument to the commonly accepted belief that symbolic execution cannot handle arrays. The substitution technique deals with constraints involving array terms with a single aggregate name, array terms with multiple aggregate names, and nested array terms. Our approach …

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 …

Formal Model And Specification Of Deadlock, Pei-Yu Li, Bruce M. Mcmillin

Computer Science Technical Reports

In this paper, we present a formal model of deadlock in a distributed system and develop the deadlock specification in terms of time-dependent predicates. Primitive activities of processes in the distributed system are specified by the predicates so that system behaviors can be described by logic operations. With the formal model, we have an insight into the definition of deadlock in local views. A rigorous proof to show the equivalence of local-time and global-time deadlock specifications is presented. The local-time deadlock specification, which defines the timing of dependence between deadlocked processes, will be useful in the correctness verification of distributed …

Distributed And Collaborative Volume Visualization, Vinod Anupam, Chandrajit Bajaj, Daniel Schikore, Matthew Schikore

Department of Computer Science Technical Reports

No abstract provided.

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.

Parallel Detection Of All Palindromes In A String, Alberto Apostolico, Dany Breslauer, Zvi Galil

Department of Computer Science Technical Reports

No abstract provided.

Geometric Approaches To Mesh Generation, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

Smoothing Vertex-Degree Bounded Polyhedra, Jörg Peters

Department of Computer Science Technical Reports

No abstract provided.

A Geometric Constraint Solver, William Bouma, Ioannis Fudos, Christoph M. Hoffmann, Jiazhen Cai, Robert Paige

Department of Computer Science Technical Reports

No abstract provided.

A Study Of Automated Estimating Of Software Cost, Steven Shouli Wang

Masters Theses

The objectives of this thesis are to survey software cost estimation methods and to discuss how the methods can be applied as conceptual knowledge in a software cost estimation expert database system. The various applications of expert database systems are discussed. Consequently, a new method to approach the software cost estimation has been proposed.

This proposed method is based upon a dozen years of analyzing software cost models which have been done by some dedicated scientists in universities, research organizations, and industry. A CASE tool called IASCE has been designed to assist the project manager to estimate a proposed project …

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, …

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 …

Facial Image Retrieval, Identification, And Inference System, Jian Kang Wu, Yew Hock Ang, Chiam Prong Lam, S. K. Moorthy, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

Recognition of a human face is very easy even to a child, but is extremely difficult for computers. Here we present a Computer Aided Facial Image Identification, Retrieval and Inference System (CAFIIRIS) for criminal identification. The system stores and manages facial images and criminal records, providing necessary image and text processing, and editing tools. Inference of facial images of different ages of a person is also possible. Access to facial images can be done via key words, fuzzy descriptions, and visual browsing.

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 …

Measuring The Effects Of Thread Placement On The Kendall Square Ksr1, Amy Apon, T D. Wagner, E Smirni, M Madhukar, L W. Dowdy

Publications

This paper describes a measurement study of the effects of thread placement on memory access times on the Kendall Square multiprocessor, the KSRl. The KSRl uses a conventional shared memory programming model in a distributed memory architecture. The architecture is based on a ring of rings of 64-bit superscalar microprocessors. The KSRl has a Cache-Only Memory Architecture (COMA). Memory consists of the local cache memoria attached to each processor. Whenever an address is accessed, the data item is automatically copied to the local cache memory module, 80 that access times for subsequent references will be minimal. If a local cache …

Memory-Adaptive External Sorting, Hwee Hwa Pang, Michael J. Carey, Miron Livny

Research Collection School Of Computing and Information Systems

In real-time and goal-oriented database systems, the amount of memory assigned to queries that sort or join large relations may fluctuate due to contention from other higher priority transactions. This study focuses on techniques that enable external sorts both to reduce their buffer usage when they lose memory, and to effectively utilize any additional buffers that are given to them. We also show how these techniques can be extended to work with sort-merge joins. A series of experiments confirms that our proposed techniques are useful for sorting and joining large relations in the face of memory fluctuations.

A Network Management Tool For The University Of Tennessee At Chattanooga Using Simple Network Management Protocol, Ghasem Shojaie

Masters Theses and Doctoral Dissertations

This research is an attempt to develop a general purpose network management tool, using the Simple Network Management Protocol, for the University of Tennessee at Chattanooga (UTC). This tool is intended to be a non vendor specific application that runs on very low cost hardware, yet provides the primary functions one needs to monitor the health of network devices such as routers and bridges. The Simple Network Management Protocol was chosen because it is an industry standard. It has fewer operators than other network management protocols; therefore, it is simpler to implement. Because of the type of network that is …

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 …

A Cognitively Motivated System For Software Component Reuse, Michael Joseph Mateas

Dissertations and Theses

Software reuse via component libraries suffers from the twin problems of code location and comprehension. The Intelligent Code Object Planner (ICOP) is a cognitively motivated system that facilitates code reuse by answering queries about how to produce an effect with the library. It can plan for effects which are not primitive with respect to the library by building a plan that incorporates multiple components. The primary subsystems of ICOP are a knowledge base which describes the ontology of the library, a natural language interface which translates user queries into a formal effect language (predicates), a planner which accepts the effect …

Parallel Genetic Algorithm For The Dag Vertex Splitting Problem, Matthias Mayer

Computer Science Technical Reports

Directed Acyclic Graphs (DGAs) are often used to model circuits and networks. The path length in such DAGs represents circuit or network delays. In the vertex splitting problem, the objective is to determine a minimum number of vertices from the graph to split such that the resulting graph has no path of length greater than a given maximum delay δ. The problem has been proven to be NP-hard. A sequential Genetic Algorithm has been developed to solve the DAG Vertex Splitting Problem. Unlike a standard Genetic Algorithm, this approach uses a variable chromosome length to represent the vertices that split …

Parallel Algorithm Fundamentals And Analysis, Bruce M. Mcmillin, Hanan Lutfiyya, Grace Tsai, Jun-Lin Liu

Computer Science Technical Reports

This session explores, through the use of formal methods, the “intuition” used in creating a parallel algorithm design and realizing this design on distributed memory hardware. The algorithm class NC and the LSTM machine are used to show why some algorithms realize their promise of speedup better than others and the algorithm class NP is used to show why other algorithms will never be good for parallelization. Performance and correctness through cooperative axiomatic reasoning and temporal reasoning provide an additional basis for understanding parallel algorithm design and specification. Finally, the realities of algorithm design are presented through partitioning and mapping …

Parallel Algorithm Fundamentals And Analysis, Bruce M. Mcmillin, Hanan Lutfiyya, Grace Tsai, Jun-Lin Liu

Computer Science Technical Reports

This session explores, through the use of formal methods, the “intuition” used in creating a parallel algorithm design and realizing this design on distributed memory hardware. The algorithm class NG and the LSTM machine are used to show why some algorithms realize their promise of speedup better than others and the algorithm class NP is used to show why other algorithms will never be good for parallelization. The realities of algorithm design are presented through partitioning and mapping issues and models. Finally, correctness through cooperative axiomatic reasoning provides an additional basis for understanding parallel algorithm design and specification and is …

X.500 Directory Service Support For Electronic Mail, Mihai G. Sirbu, Fikret ErçAl

Computer Science Technical Reports

One of the difficult problems on the Internet is finding the electronic mail addresses of users. In practice, there are some indirect ways of finding these addresses such as the finger program in UNIX, but almost all of these methods require the user to know the exact host name of the destination. What is most desirable is an automated mechanism which provides the e-mail addresses of users if some minimal information about the destination site is known.

This thesis describes the design of such a directory service support system, based on the X.500 Series of CCITT Recommendation, for the elm …

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 …

Converting A Rational Function To A Standard Nurbs Representation, Chandrajit Bajaj, Guoliang Xu

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.

A Taxonomic And Analytical Survey Of Multidatabase Systems, Tony Schaller, Omran A. Bukhres, Jiansan Chen, Ahmed K. 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.

Convergence Analysis Of A Non-Overlapping Domain Decomposition Method For Elliptic Pdes, John R. Rice, E. A. Vavalis, D. Yang

Department of Computer Science Technical Reports

No abstract provided.