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A Unifying Version Model for Objects and Schema in Object-Oriented Database System

Description: There have been a number of different versioning models proposed. The research in this area can be divided into two categories: object versioning and schema versioning. In this dissertation, both problem domains are considered as a single unit. This dissertation describes a unifying version model (UVM) for maintaining changes to both objects and schema. UVM handles schema versioning operations by using object versioning techniques. The result is that the UVM allows the OODBMS to be much smaller… more
Date: August 1997
Creator: Shin, Dongil
Partner: UNT Libraries
open access

Rollback Reduction Techniques Through Load Balancing in Optimistic Parallel Discrete Event Simulation

Description: Discrete event simulation is an important tool for modeling and analysis. Some of the simulation applications such as telecommunication network performance, VLSI logic circuits design, battlefield simulation, require enormous amount of computing resources. One way to satisfy this demand for computing power is to decompose the simulation system into several logical processes (Ip) and run them concurrently. In any parallel discrete event simulation (PDES) system, the events are ordered according … more
Date: May 1996
Creator: Sarkar, Falguni
Partner: UNT Libraries
open access

An Algorithm for the PLA Equivalence Problem

Description: The Programmable Logic Array (PLA) has been widely used in the design of VLSI circuits and systems because of its regularity, flexibility, and simplicity. The equivalence problem is typically to verify that the final description of a circuit is functionally equivalent to its initial description. Verifying the functional equivalence of two descriptions is equivalent to proving their logical equivalence. This problem of pure logic is essential to circuit design. The most widely used technique to … more
Date: December 1995
Creator: Moon, Gyo Sik
Partner: UNT Libraries
open access

Convexity-Preserving Scattered Data Interpolation

Description: Surface fitting methods play an important role in many scientific fields as well as in computer aided geometric design. The problem treated here is that of constructing a smooth surface that interpolates data values associated with scattered nodes in the plane. The data is said to be convex if there exists a convex interpolant. The problem of convexity-preserving interpolation is to determine if the data is convex, and construct a convex interpolant if it exists.
Date: December 1995
Creator: Leung, Nim Keung
Partner: UNT Libraries
open access

Exon/Intron Discrimination Using the Finite Induction Pattern Matching Technique

Description: DNA sequence analysis involves precise discrimination of two of the sequence's most important components: exons and introns. Exons encode the proteins that are responsible for almost all the functions in a living organism. Introns interrupt the sequence coding for a protein and must be removed from primary RNA transcripts before translation to protein can occur. A pattern recognition technique called Finite Induction (FI) is utilized to study the language of exons and introns. FI is especially… more
Date: December 1997
Creator: Taylor, Pamela A., 1941-
Partner: UNT Libraries
open access

Practical Cursive Script Recognition

Description: This research focused on the off-line cursive script recognition application. The problem is very large and difficult and there is much room for improvement in every aspect of the problem. Many different aspects of this problem were explored in pursuit of solutions to create a more practical and usable off-line cursive script recognizer than is currently available.
Date: August 1995
Creator: Carroll, Johnny Glen, 1953-
Partner: UNT Libraries
open access

Concurrent Pattern Recognition and Optical Character Recognition

Description: The problem of interest as indicated is to develop a general purpose technique that is a combination of the structural approach, and an extension of the Finite Inductive Sequence (FI) technique. FI technology is pre-algebra, and deals with patterns for which an alphabet can be formulated.
Date: August 1991
Creator: An, Kyung Hee
Partner: UNT Libraries
open access

Efficient Parallel Algorithms and Data Structures Related to Trees

Description: The main contribution of this dissertation proposes a new paradigm, called the parentheses matching paradigm. It claims that this paradigm is well suited for designing efficient parallel algorithms for a broad class of nonnumeric problems. To demonstrate its applicability, we present three cost-optimal parallel algorithms for breadth-first traversal of general trees, sorting a special class of integers, and coloring an interval graph with the minimum number of colors.
Date: December 1991
Creator: Chen, Calvin Ching-Yuen
Partner: UNT Libraries
open access

Performance Study of Concurrent Search Trees and Hash Algorithms on Multiprocessors Systems

Description: This study examines the performance of concurrent algorithms for B-trees and linear hashing. B-trees are widely used as an access method for large, single key, database files, stored in lexicographic order on secondary storage devices. Linear hashing is a fast and reliable hash algorithm, suitable for accessing records stored unordered in buckets. This dissertation presents performance results on implementations of concurrent Bunk-tree and linear hashing algorithms, using lock-based, partitione… more
Date: May 1996
Creator: Demuynck, Marie-Anne
Partner: UNT Libraries
open access

Linearly Ordered Concurrent Data Structures on Hypercubes

Description: This thesis presents a simple method for the concurrent manipulation of linearly ordered data structures on hypercubes. The method is based on the existence of a pruned binomial search tree rooted at any arbitrary node of the binary hypercube. The tree spans any arbitrary sequence of n consecutive nodes containing the root, using a fan-out of at most [log₂ 𝑛] and a depth of [log₂ 𝑛] +1. Search trees spanning non-overlapping processor lists are formed using only local information, and can be use… more
Date: August 1992
Creator: John, Ajita
Partner: UNT Libraries
open access

DRVBLD: a UNIX Device Driver Builder

Description: New peripheral devices are being developed at an ever increasing rate. Before such accessories can be used in the UNIX environment (UNIX is a trademark of Bell Laboratories), they must be able to communicate with the operating system. This involves writing a device driver for each device. In order to do this, very detailed knowledge is required of both the device to be integrated and the version of UNIX to which it will be attached. The process is long, detailed and prone to subtle problems and… more
Date: May 1992
Creator: Cano, Agustin F.
Partner: UNT Libraries
open access

An Efficient Hybrid Heuristic and Probabilistic Model for the Gate Matrix Layout Problem in VLSI Design

Description: In this thesis, the gate matrix layout problem in VLSI design is considered where the goal is to minimize the number of tracks required to layout a given circuit and a taxonomy of approaches to its solution is presented. An efficient hybrid heuristic is also proposed for this combinatorial optimization problem, which is based on the combination of probabilistic hill-climbing technique and greedy method. This heuristic is tested experimentally with respect to four existing algorithms. As test ca… more
Date: August 1993
Creator: Bagchi, Tanuj
Partner: UNT Libraries
open access

The Telecommunications Network Configuration Optimization Problem

Description: The purpose of telecommunication network configuration optimization is to find the best homing relationship between tandems and switches so as to minimize interswitch traffic, or equivalently to maximize intraswitch traffic. Note that, since minimal interswitch traffic implies minimal IMT utilization, communication costs will also be minimal.
Date: August 1995
Creator: Azizoglu, Mustafa C.
Partner: UNT Libraries
open access

Merlin Classifier System

Description: There is a natural tendency for biological systems to change as their environments change. The fittest in the biological systems survive, adapt to their environment, and multiply while the weakest in the environment diminish. There have been attempts in computer science to model the processes of natural selection and survival which occur in biological systems in order to obtain more efficient and effective machine-learning algorithms. Genetic algorithms are the result of these attempts.
Date: May 1991
Creator: Pantermuehl, Brenda N.
Partner: UNT Libraries
open access

Intrinsic and Extrinsic Adaptation in a Simulated Combat Environment

Description: Genetic algorithm and artificial life techniques are applied to the development of challenging and interesting opponents in a combat-based computer game. Computer simulations are carried out against an idealized human player to gather data on the effectiveness of the computer generated opponents.
Date: May 1995
Creator: Dombrowsky, Steven P. (Steven Paul)
Partner: UNT Libraries
open access

Computational Complexity of Hopfield Networks

Description: There are three main results in this dissertation. They are PLS-completeness of discrete Hopfield network convergence with eight different restrictions, (degree 3, bipartite and degree 3, 8-neighbor mesh, dual of the knight's graph, hypercube, butterfly, cube-connected cycles and shuffle-exchange), exponential convergence behavior of discrete Hopfield network, and simulation of Turing machines by discrete Hopfield Network.
Date: August 1998
Creator: Tseng, Hung-Li
Partner: UNT Libraries
open access

Efficient Linked List Ranking Algorithms and Parentheses Matching as a New Strategy for Parallel Algorithm Design

Description: The goal of a parallel algorithm is to solve a single problem using multiple processors working together and to do so in an efficient manner. In this regard, there is a need to categorize strategies in order to solve broad classes of problems with similar structures and requirements. In this dissertation, two parallel algorithm design strategies are considered: linked list ranking and parentheses matching.
Date: December 1993
Creator: Halverson, Ranette Hudson
Partner: UNT Libraries
open access

Quality-of-Service Provisioning and Resource Reservation Mechanisms for Mobile Wireless Networks

Description: In this thesis, a framework for Quality of Service provisioning in next generation wireless access networks is proposed. The framework aims at providing a differentiated service treatment to real-time (delay-sensitive) and non-real-time (delay-tolerant) multimedia traffic flows at the link layer. Novel techniques such as bandwidth compaction, channel reservation, and channel degradation are proposed. Using these techniques, we develop a call admission control algorithm and a call control block … more
Date: August 1998
Creator: Jayaram, Rajeev, 1971-
Partner: UNT Libraries
open access

A Multi-Time Scale Learning Mechanism for Neuromimic Processing

Description: Learning and representing and reasoning about temporal relations, particularly causal relations, is a deep problem in artificial intelligence (AI). Learning such representations in the real world is complicated by the fact that phenomena are subject to multiple time scale influences and may operate with a strange attractor dynamic. This dissertation proposes a new computational learning mechanism, the adaptrode, which, used in a neuromimic processing architecture may help to solve some of these… more
Date: August 1994
Creator: Mobus, George E. (George Edward)
Partner: UNT Libraries
open access

Symplectic Integration of Nonseparable Hamiltonian Systems

Description: Numerical methods are usually necessary in solving Hamiltonian systems since there is often no closed-form solution. By utilizing a general property of Hamiltonians, namely the symplectic property, all of the qualities of the system may be preserved for indefinitely long integration times because all of the integral (Poincare) invariants are conserved. This allows for more reliable results and frequently leads to significantly shorter execution times as compared to conventional methods. The res… more
Date: May 1996
Creator: Curry, David M. (David Mason)
Partner: UNT Libraries
open access

A Theoretical Network Model and the Incremental Hypercube-Based Networks

Description: The study of multicomputer interconnection networks is an important area of research in parallel processing. We introduce vertex-symmetric Hamming-group graphs as a model to design a wide variety of network topologies including the hypercube network.
Date: May 1995
Creator: Mao, Ai-sheng
Partner: UNT Libraries
open access

Using Extended Logic Programs to Formalize Commonsense Reasoning

Description: In this dissertation, we investigate how commonsense reasoning can be formalized by using extended logic programs. In this investigation, we first use extended logic programs to formalize inheritance hierarchies with exceptions by adopting McCarthy's simple abnormality formalism to express uncertain knowledge. In our representation, not only credulous reasoning can be performed but also the ambiguity-blocking inheritance and the ambiguity-propagating inheritance in skeptical reasoning are simul… more
Date: May 1992
Creator: Horng, Wen-Bing
Partner: UNT Libraries
open access

Recognition of Face Images

Description: The focus of this dissertation is a methodology that enables computer systems to classify different up-front images of human faces as belonging to one of the individuals to which the system has been exposed previously. The images can present variance in size, location of the face, orientation, facial expressions, and overall illumination. The approach to the problem taken in this dissertation can be classified as analytic as the shapes of individual features of human faces are examined separate… more
Date: December 1994
Creator: Pershits, Edward
Partner: UNT Libraries
open access

Using Normal Deduction Graphs in Common Sense Reasoning

Description: This investigation proposes a powerful formalization of common sense knowledge based on function-free normal deduction graphs (NDGs) which form a powerful tool for deriving Horn and non-Horn clauses without functions. Such formalization allows common sense reasoning since it has the ability to handle not only negative but also incomplete information.
Date: May 1992
Creator: Munoz, Ricardo A. (Ricardo Alberto)
Partner: UNT Libraries
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