The Principles of Relational Databases (open access)

The Principles of Relational Databases

Every business has to keep records. Sometimes these records have to be presented in a standardized form, or more often they can be arranged in any way that suits the user. Business records are of little use unless they can be referred to quickly, to provide information when it is required. In computer systems it is essential to be able to recognize any particular record in a data file which is a collection of similar records kept on secondary computer storage devices.
Date: August 1986
Creator: Hsu, Chaur-Chun
System: The UNT Digital Library
Text Processing for Thai Characters (open access)

Text Processing for Thai Characters

The purpose of this project is 1) to create a Thai character set for text processing, 2) to write a text processing program for the character set, and 3) to allow users to create and save the text.
Date: August 1983
Creator: Tarapoom, Nirut
System: The UNT Digital Library
FORTRAN Graphics Library (open access)

FORTRAN Graphics Library

The objective of this work is to help the faculty, staffs and students of NTSU to use the CalComp plotting facility very easily. Therefore, this work is written in such a step by step and self-explanatory way to help the reader to understand and grasp the essential technique of the computer plotting. Each subroutine illustrated in this work has been run and checked by our NTSU computer-CalComp plotting facility; the results of sample programs and illustrated graphs are believed to be very useful to understand each individual subroutine. Basically, software packages are stored in the magnetic disk of the IBM 360 computer as the standard graphic subroutines. These subroutines were written in FORTRAN IV. The user can write the driving program to call these subroutines and also inputs the desire data to the computer for computation. The results of computation will be outputed and stored in the magnetic tape.
Date: August 1979
Creator: Ling-Yann, Huang
System: The UNT Digital Library
PILOT for the Apple II Microcomputer (open access)

PILOT for the Apple II Microcomputer

PILOT (Programmed Inquiry, Learning or Teaching) is a simple, conversational language developed in 1969 by John A. Starkweather at the University of California Medical Center in San Francisco. Originally designed for computer assisted instructional needs, PILOT also has been effectively used as an introductory computer language. The PILOT system developed for the Apple II microcomputer consists of two programs, PILOT EDITOR and PILOT DRIVER, which are written in Applesoft and which use the Apple II disk operating system. The PILOT system was designed to facilitate easy authoring and execution of programs written in an extended version of the PILOT language. Due to the memory requirements of the programs and the Apple II disk operating system, the PILOT system described here should be executed on a machine with at least 32k bytes of random access memory.
Date: August 1979
Creator: Ellis, Richard George
System: The UNT Digital Library
Triangle: A Teaching Program of High School Geometry (open access)

Triangle: A Teaching Program of High School Geometry

Among the early applications of computers, one can find frequent mention of intelligent instructional systems. Such intelligent instructional systems represent a new generation of learner-based computer aided instruction, preceded in time by the original frame-based systems and an intervening generation of expert-based CAI. The history of CAI is characterized by three generations: Frame-based CAI, Expert-based CAI and Learner-based CAI.
Date: August 1983
Creator: Chen, Yei-Huang
System: The UNT Digital Library
FORTRAN Optimizations at the Source Code Level (open access)

FORTRAN Optimizations at the Source Code Level

This paper discusses FORTRAN optimizations that the user can perform manually at the source code level to improve object code performance. It makes use of descriptive examples within the text of the paper for explanatory purposes. The paper defines key areas in writing a FORTRAN program and recommends ways to improve efficiency in these areas.
Date: August 1977
Creator: Barber, Willie D.
System: The UNT Digital Library
A Computer Algorithm for Synthetic Seismograms (open access)

A Computer Algorithm for Synthetic Seismograms

Synthetic seismograms are a computer-generated aid in the search for hydrocarbons. Heretofore the solution has been done by z-transforms. This thesis presents a solution based on the method of finite differences. The resulting algorithm is fast and compact. The method is applied to three variations of the problem, all three are reduced to the same approximating equation, which is shown to be optimal, in that grid refinement does not change it. Two types of algorithms are derived from the equation. The number of obvious multiplications, additions and subtractions of each is analyzed. Critical section of each requires one multiplication, two additions and two subtractions. Four sample synthetic seismograms are shown. Implementation of the new algorithm runs twice as fast as previous computer program.
Date: August 1977
Creator: Isaacson, James
System: The UNT Digital Library
Semaphore Solutions for General Mutual Exclusion Problems (open access)

Semaphore Solutions for General Mutual Exclusion Problems

Automatic generation of starvation-free semaphore solutions to general mutual exclusion problems is discussed. A reduction approach is introduced for recognizing edge-solvable problems, together with an O(N^2) algorithm for graph reduction, where N is the number of nodes. An algorithm for the automatic generation of starvation-free edge-solvable solutions is presented. The solutions are proved to be very efficient. For general problems, there are two ways to generate efficient solutions. One associates a semaphore with every node, the other with every edge. They are both better than the standard monitor—like solutions. Besides strong semaphores, solutions using weak semaphores, weaker semaphores and generalized semaphores are also considered. Basic properties of semaphore solutions are also discussed. Tools describing the dynamic behavior of parallel systems, as well as performance criteria for evaluating semaphore solutions are elaborated.
Date: August 1988
Creator: Yue, Kwok B. (Kwok Bun)
System: The UNT Digital Library
A Graphical, Database-Querying Interface for Casual, Naive Computer Users (open access)

A Graphical, Database-Querying Interface for Casual, Naive Computer Users

This research is concerned with some aspects of the retrieval of information from database systems by casual, naive computer users. A "casual user" is defined as an individual who only wishes to execute queries perhaps once or twice a month, and a "naive user" is someone who has little or no expertise in operating a computer and, more specifically for the purposes of this study, is not practiced at querying a database. The research initially focuses on a specific group of casual, naive users, namely a group of clinicians, and analyzes their characteristics as they pertain to the retrieval of information from a computer database. The characteristics thus elicited are then used to create the requirements for a database interface that would, potentially, be acceptable to this group. An interface having the desired requirements is then proposed. This interface consists, from a user's perspective, of three basic components. A graphical model gives a picture of the database structure. Windows give the ability to view different areas of the database, physically group together items that come under one logical heading and provide the user with immediate access to the data item names used by the system. Finally, a natural language query …
Date: August 1985
Creator: Burgess, Clifford G. (Clifford Grenville)
System: The UNT Digital Library
Computer Realization of Human Music Cognition (open access)

Computer Realization of Human Music Cognition

This study models the human process of music cognition on the digital computer. The definition of music cognition is derived from the work in music cognition done by the researchers Carol Krumhansl and Edward Kessler, and by Mari Jones, as well as from the music theories of Heinrich Schenker. The computer implementation functions in three stages. First, it translates a musical "performance" in the form of MIDI (Musical Instrument Digital Interface) messages into LISP structures. Second, the various parameters of the performance are examined separately a la Jones's joint accent structure, quantified according to psychological findings, and adjusted to a common scale. The findings of Krumhansl and Kessler are used to evaluate the consonance of each note with respect to the key of the piece and with respect to the immediately sounding harmony. This process yields a multidimensional set of points, each of which is a cognitive evaluation of a single musical event within the context of the piece of music within which it occurred. This set of points forms a metric space in multi-dimensional Euclidean space. The third phase of the analysis maps the set of points into a topology-preserving data structure for a Schenkerian-like middleground structural analysis. This …
Date: August 1988
Creator: Albright, Larry E. (Larry Eugene)
System: The UNT Digital Library
A Unifying Version Model for Objects and Schema in Object-Oriented Database System (open access)

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

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 than previous systems. Also, programmers need know only one set of versioning operations; thus, reducing the learning time by half. This dissertation shows that UVM is a simple but semantically sound and powerful version model for both objects and schema.
Date: August 1997
Creator: Shin, Dongil
System: The UNT Digital Library
Practical Cursive Script Recognition (open access)

Practical Cursive Script Recognition

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-
System: The UNT Digital Library
Computational Complexity of Hopfield Networks (open access)

Computational Complexity of Hopfield Networks

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
System: The UNT Digital Library
Automatic Speech Recognition Using Finite Inductive Sequences (open access)

Automatic Speech Recognition Using Finite Inductive Sequences

This dissertation addresses the general problem of recognition of acoustic signals which may be derived from speech, sonar, or acoustic phenomena. The specific problem of recognizing speech is the main focus of this research. The intention is to design a recognition system for a definite number of discrete words. For this purpose specifically, eight isolated words from the T1MIT database are selected. Four medium length words "greasy," "dark," "wash," and "water" are used. In addition, four short words are considered "she," "had," "in," and "all." The recognition system addresses the following issues: filtering or preprocessing, training, and decision-making. The preprocessing phase uses linear predictive coding of order 12. Following the filtering process, a vector quantization method is used to further reduce the input data and generate a finite inductive sequence of symbols representative of each input signal. The sequences generated by the vector quantization process of the same word are factored, and a single ruling or reference template is generated and stored in a codebook. This system introduces a new modeling technique which relies heavily on the basic concept that all finite sequences are finitely inductive. This technique is used in the training stage. In order to accommodate the variabilities …
Date: August 1996
Creator: Cherri, Mona Youssef, 1956-
System: The UNT Digital Library
A Programming Language For Concurrent Processing (open access)

A Programming Language For Concurrent Processing

This thesis is a proposed solution to the problem of including an effective interrupt mechanism in the set of concurrent- processing primitives of a block-structured programming language or system. The proposed solution is presented in the form of a programming language definition and model. The language is called TRIPLE.
Date: August 1972
Creator: Jackson, Portia M.
System: The UNT Digital Library
Building an Intelligent Filtering System Using Idea Indexing (open access)

Building an Intelligent Filtering System Using Idea Indexing

The widely used vector model maintains its popularity because of its simplicity, fast speed, and the appeal of using spatial proximity for semantic proximity. However, this model faces a disadvantage that is associated with the vagueness from keywords overlapping. Efforts have been made to improve the vector model. The research on improving document representation has been focused on four areas, namely, statistical co-occurrence of related items, forming term phrases, grouping of related words, and representing the content of documents. In this thesis, we propose the idea-indexing model to improve document representation for the filtering task in IR. The idea-indexing model matches document terms with the ideas they express and indexes the document with these ideas. This indexing scheme represents the document with its semantics instead of sets of independent terms. We show in this thesis that indexing with ideas leads to better performance.
Date: August 2003
Creator: Yang, Li
System: The UNT Digital Library
XML-Based Agent Scripts and Inference Mechanisms (open access)

XML-Based Agent Scripts and Inference Mechanisms

Natural language understanding has been a persistent challenge to researchers in various computer science fields, in a number of applications ranging from user support systems to entertainment and online teaching. A long term goal of the Artificial Intelligence field is to implement mechanisms that enable computers to emulate human dialogue. The recently developed ALICEbots, virtual agents with underlying AIML scripts, by A.L.I.C.E. foundation, use AIML scripts - a subset of XML - as the underlying pattern database for question answering. Their goal is to enable pattern-based, stimulus-response knowledge content to be served, received and processed over the Web, or offline, in the manner similar to HTML and XML. In this thesis, we describe a system that converts the AIML scripts to Prolog clauses and reuses them as part of a knowledge processor. The inference mechanism developed in this thesis is able to successfully match the input pattern with our clauses database even if words are missing. We also emulate the pattern deduction algorithm of the original logic deduction mechanism. Our rules, compatible with Semantic Web standards, bring structure to the meaningful content of Web pages and support interactive content retrieval using natural language.
Date: August 2003
Creator: Sun, Guili
System: The UNT Digital Library
Modeling Complex Forest Ecology in a Parallel Computing Infrastructure (open access)

Modeling Complex Forest Ecology in a Parallel Computing Infrastructure

Effective stewardship of forest ecosystems make it imperative to measure, monitor, and predict the dynamic changes of forest ecology. Measuring and monitoring provides us a picture of a forest's current state and the necessary data to formulate models for prediction. However, societal and natural events alter the course of a forest's development. A simulation environment that takes into account these events will facilitate forest management. In this thesis, we describe an efficient parallel implementation of a land cover use model, Mosaic, and discuss the development efforts to incorporate spatial interaction and succession dynamics into the model. To evaluate the performance of our implementation, an extensive set of simulation experiments was carried out using a dataset representing the H.J. Andrews Forest in the Oregon Cascades. Results indicate that a significant reduction in the simulation execution time of our parallel model can be achieved as compared to uni-processor simulations.
Date: August 2003
Creator: Mayes, John
System: The UNT Digital Library
Visualization of Surfaces and 3D Vector Fields (open access)

Visualization of Surfaces and 3D Vector Fields

Visualization of trivariate functions and vector fields with three components in scientific computation is still a hard problem in compute graphic area. People build their own visualization packages for their special purposes. And there exist some general-purpose packages (MatLab, Vis5D), but they all require extensive user experience on setting all the parameters in order to generate images. We present a simple package to produce simplified but productive images of 3-D vector fields. We used this method to render the magnetic field and current as solutions of the Ginzburg-Landau equations on a 3-D domain.
Date: August 2002
Creator: Li, Wentong
System: The UNT Digital Library
The Design and Implementation of a Prolog Parser Using Javacc (open access)

The Design and Implementation of a Prolog Parser Using Javacc

Operatorless Prolog text is LL(1) in nature and any standard LL parser generator tool can be used to parse it. However, the Prolog text that conforms to the ISO Prolog standard allows the definition of dynamic operators. Since Prolog operators can be defined at run-time, operator symbols are not present in the grammar rules of the language. Unless the parser generator allows for some flexibility in the specification of the grammar rules, it is very difficult to generate a parser for such text. In this thesis we discuss the existing parsing methods and their modified versions to parse languages with dynamic operator capabilities. Implementation details of a parser using Javacc as a parser generator tool to parse standard Prolog text is provided. The output of the parser is an “Abstract Syntax Tree” that reflects the correct precedence and associativity rules among the various operators (static and dynamic) of the language. Empirical results are provided that show that a Prolog parser that is generated by the parser generator like Javacc is comparable in efficiency to a hand-coded parser.
Date: August 2002
Creator: Gupta, Pankaj
System: The UNT Digital Library
Control Mechanisms and Recovery Techniques for Real-Time Data Transmission Over the Internet. (open access)

Control Mechanisms and Recovery Techniques for Real-Time Data Transmission Over the Internet.

Streaming multimedia content with UDP has become popular over distributed systems such as an Internet. This may encounter many losses due to dropped packets or late arrivals at destination since UDP can only provide best effort delivery. Even UDP doesn't have any self-recovery mechanism from congestion collapse or bursty loss to inform sender of the data to adjust future transmission rate of data like in TCP. So there is a need to incorporate various control schemes like forward error control, interleaving, and congestion control and error concealment into real-time transmission to prevent from effect of losses. Loss can be repaired by retransmission if roundtrip delay is allowed, otherwise error concealment techniques will be used based on the type and amount of loss. This paper implements the interleaving technique with packet spacing of varying interleaver block size for protecting real-time data from loss and its effect during transformation across the Internet. The packets are interleaved and maintain some time gap between two consecutive packets before being transmitted into the Internet. Thus loss of packets can be reduced from congestion and preventing loss of consecutive packets of information when a burst of several packets are lost. Several experiments have been conducted with …
Date: August 2002
Creator: Battula, Venkata Krishna Rao
System: The UNT Digital Library
Higher Compression from the Burrows-Wheeler Transform with New Algorithms for the List Update Problem (open access)

Higher Compression from the Burrows-Wheeler Transform with New Algorithms for the List Update Problem

Burrows-Wheeler compression is a three stage process in which the data is transformed with the Burrows-Wheeler Transform, then transformed with Move-To-Front, and finally encoded with an entropy coder. Move-To-Front, Transpose, and Frequency Count are some of the many algorithms used on the List Update problem. In 1985, Competitive Analysis first showed the superiority of Move-To-Front over Transpose and Frequency Count for the List Update problem with arbitrary data. Earlier studies due to Bitner assumed independent identically distributed data, and showed that while Move-To-Front adapts to a distribution faster, incurring less overwork, the asymptotic costs of Frequency Count and Transpose are less. The improvements to Burrows-Wheeler compression this work covers are increases in the amount, not speed, of compression. Best x of 2x-1 is a new family of algorithms created to improve on Move-To-Front's processing of the output of the Burrows-Wheeler Transform which is like piecewise independent identically distributed data. Other algorithms for both the middle stage of Burrows-Wheeler compression and the List Update problem for which overwork, asymptotic cost, and competitive ratios are also analyzed are several variations of Move One From Front and part of the randomized algorithm Timestamp. The Best x of 2x - 1 family includes Move-To-Front, …
Date: August 2001
Creator: Chapin, Brenton
System: The UNT Digital Library
Algorithms for Efficient Utilization of Wireless Bandwidth and to Provide Quality-of-Service in Wireless Networks (open access)

Algorithms for Efficient Utilization of Wireless Bandwidth and to Provide Quality-of-Service in Wireless Networks

This thesis presents algorithms to utilize the wireless bandwidth efficiently and at the same time meet the quality of service (QoS) requirements of the users. In the proposed algorithms we present an adaptive frame structure based upon the airlink frame loss probability and control the admission of call requests into the system based upon the load on the system and the QoS requirements of the incoming call requests. The performance of the proposed algorithms is studied by developing analytical formulations and simulation experiments. Finally we present an admission control algorithm which uses an adaptive delay computation algorithm to compute the queuing delay for each class of traffic and adapts the service rate and the reliability in the estimates based upon the deviation in the expected and obtained performance. We study the performance of the call admission control algorithm by simulation experiments. Simulation results for the adaptive frame structure algorithm show an improvement in the number of users in the system but there is a drop in the system throughput. In spite of the lower throughput the adaptive frame structure algorithm has fewer QoS delay violations. The adaptive call admission control algorithm adapts the call dropping probability of different classes of …
Date: August 2000
Creator: Kakani, Naveen Kumar
System: The UNT Digital Library