Computer Sciences Commons^™

Some Applications Of Constructive Real Algebraic Geometry, Chandrajit L. Bajaj

Department of Computer Science Technical Reports

No abstract provided.

Semantic Problems Of Generative, Constraint Based Design, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.

A Distributed Memory Algorithm For 3-D Fft, Calin R. Costian, Dan C. Marinescu

Department of Computer Science Technical Reports

No abstract provided.

Gencray Language Reference Manual, Version 2, Sanjiva Weerawarana, Ann C. Catlin, Elias N. Houstis, John R. Rice

Department of Computer Science Technical Reports

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 …

Entity Identification In Database Integration: An Evidential Reasoning Approach, Ee Peng Lim, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

Entity identification is the problem of matching object instances from different databases which correspond to the same real-world entity. In this paper, we present a 2-step entity identification process in which attributes for matching tuples may be missing in certain tuples, and thus need to be derived prior to the matching. To match tuples, we require identity rules which specify the conditions to be satisfied by a pair of tuples, from different databases, before they can be considered as modeling the same real-world entity. We also introduce ILFD's (instance-level functional dependencies) as a form of inference rules which derive the …

Rsvp: A New Resource Reservation Protocol, Daniel Zappala, Stephen Deering, Deborah Estrin, Scott Shenker, Lixia Zhang

Faculty Publications

The current Internet architecture, embodied in the Internet Protocol (IP) network protocol, offers a very simple service model: point-to-point best-effort service. In recent years, several new classes of distributed applications have been developed, such as remote video, multimedia conferencing, data fusion, visualization, and virtual reality. It is becoming increasingly clear that the Internet’s primitive service model is inadequate for these new applications. This inadequacy stems from the failure of the point-to-point best-effort service model to address two application requirements. First, many of these applications are very sensitive to the quality of service their packets receive. For a network to deliver …

Computerized Vehicle Routing Programs And Their Effect On Vehicle Utilization In The Air Force, Rex E. Adee, William G. Howard

Theses and Dissertations

The purpose of this study is to determine if a commercial computerized vehicle routing program improves vehicle utilization for an Air Force base transportation organization. First, the researchers investigate current routing procedures of Air Force base transportation organizations. Second, researchers identify a commercial computerized vehicle routing program that enables the authors to conduct a comparison of vehicle utilization rates between an Air Force base transportation organization and commercial computerized vehicle routing programs. The study reveals that implementing a computerized vehicle routing program in place of a manual routing procedure does not improve vehicle utilization. However, the study reveals some limitations …

On The Automation Of Object-Oriented Requirements Analysis, Nancy L. Crowley

Theses and Dissertations

The research investigated the possibility that an object-oriented requirements analysis (OORA) specification model can be represented in a computer system and used as a basis for the elicitation of the information necessary for the development of an object-oriented specification for a particular problem. The proof-of-concept system developed is called the OORA automated Knowledge System (OAKS). OAKS contains a generic domain model that is modified to satisfy a particular problem in the domain. The core of OAKS is a reusable domain model, which represents a domain of interest. The domain model is used as a basis for user changes that are …

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 …

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 …

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 …

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 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, …

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.

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

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.

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 …

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.

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 …

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 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 …