Digital Commons Network^™

Scintillation Behind The Collecting Lens Of A Receiver, Clarissa A. Fleming Russell

Retrospective Theses and Dissertations

One of the negative effects that a laser beam experiences as it propagates through the atmosphere is intensity fluctuations or scintillation. Because scintillation-- as it pertains to laser radar and laser satellite communication systems-- is the main subject of this research, the assumption of an optical element ( such as a Gaussian lens) along the propagation path in front of the detector is valid. The mathematical addition of optical elements to the propagation path is treated using the ABCD ray matrix method. The expression for scintillation is derived, analyzed, and numerically calculated for positions to the left and right of …

View-Centric Reasoning About Parallel And Distributed Computation, Marc L. Smith

Retrospective Theses and Dissertations

The development of distributed applications has not progressed as rapidly as its enabling technologies. In part, this is due to the difficulty of reasoning about such complex systems. In contrast to sequential systems, parallel systems give rise to parallel events, and the resulting uncertainty of the observed order of these events. Loosely coupled distributed systems complicate this even further by introducing the element of multiple imperfect observers of these parallel events. The goal of this dissertation is to advance parallel and distributed systems development by producing a parameterized model that can be instantiated to reflect the computation and coordination properties …

Optical Performance Of Grazing Incidence X-Ray / Euv Telescopes For Space Science Applications, Patrick Louis Thompson

Retrospective Theses and Dissertations

The science and technology of X-rays has only been part of human achievement for the past 100 years, while the study of image formation in general has endured for as long as 1000 years. The ability to conceive, design, and fabricate X-ray imagers, moreover, has existed for only the past 70 years, and X-ray astronomical telescopes have been in use for a mere 35 years. Considering that aplanatic, normal incidence telescope designs required more than 400 years to perfect, it is most interesting to note that the development of ‘aplanatic’ grazing incidence telescopes has taken only about 40 years. In …

An Intelligent Editor For Natural Language Processing Of Unrestricted Text, Demetrios George Glinos

Retrospective Theses and Dissertations

The understanding of natural language by computational methods has been a continuing and elusive problem in artificial intelligence. In recent years there has been a resurgence in natural language processing research. Much of this work has been on empirical or corpus-based methods which use a data-driven approach to train systems on large amounts of real language data. Using corpus-based methods, the performance of part-of-speech (POS) taggers, which assign to the individual words of a sentence their appropriate part of speech category (e.g., noun, verb, preposition), now rivals human performance levels, achieving accuracies exceeding 95%. Such taggers have proved useful as …

Well Characteristics Influencing Microscopic Particulate Analysis Risk Index, Robert Christopher Sharek

Retrospective Theses and Dissertations

Cryptosporidium parvum is a common surface water contaminant that can cause illness in human beings. The presence of this etiological agent in groundwater identifies the groundwater as under the direct influence (GWUDI) of surface water. Currently the determination of GWUDI water sources requires an expensive, labor-intensive laboratory procedure called the Microscopic Particulate Analysis (MPA). The results of the MPA provide a risk index that rates the degree of surface water contamination. The objective of this study is to identify other methods of identifying GWUDI of surface waters, such as well characteristics and hydrogeologic factors which may contribute to higher MPA …

Finding Paths In The Rotation Graph Of Binary Trees, Rodney O. Rogers

Retrospective Theses and Dissertations

A binary tree coding scheme is a bijection mapping a set of binary trees to a set of integer tuples called codewords. One problem considered in the literature is that of listing the codewords for n-node binary trees, such that successive codewords represent trees differing by a single rotation, a standard operation for rebalancing binary search trees. Then, the codeword sequence corresponds to an Hamiltonian path in the rotation graph R_n of binary trees, where each node is labelled with an n-node binary tree, and an edge connects two nodes when their trees differ by a …

Experimenting With The Finite Element Method In The Calculation Of Radiosity Form Factors, Donna Marie Chesteen

Retrospective Theses and Dissertations

Radiosity has been used to create some of the most photorealistic computer-generated images to date. The problem, however, is that radiosity algorithms are so computationally and memory expensive that few applications can employ them successfully. Form factor calculation is the most costly part of the process. This report describes an algorithm for using the finite element method to reduce the amount of time that is used in the form factor calculation portion of the radiosity algorithm. This technique for form factor calculation significantly reduces the number of projections done at each iteration by using shape functions to determine the distribution …

Shape Reconstruction From Shading Using Linear Approximation, Ping Sing Tsai

Retrospective Theses and Dissertations

Shape from shading (SFS) deals with the recovery of 3D shape from a single monocular image. This problem was formally introduced by Horn in the early 1970s. Since then it has received considerable attention, and several efforts have been made to improve the shape recovery. In this thesis, we present a fast SFS algorithm, which is a purely local method and is highly parallelizable. In our approach, we first use the discrete approximations for surface gradients, p and q, using finite differences, then linearize the reflectance function in depth, Z ( x , y), instead of p and q. This …

Behavior Of The Solutions To A Functional Equation Which Equates A Function's Inverse To Its Reciprocal, Robert Rudolph Anschuetz

Retrospective Theses and Dissertations

This thesis explores the behavior of solutions of the functional equation f-1(x)= 1/f(x) for x ε Dom(f), where f is a real-valued function of a real variable. It is quite common to mistake the notation f^-1, which means the inverse of f with respect to composition with the inverse of f with respect to multiplication, usually denoted by 1/f. This thesis shows that although f^-1 and 1/f are usually different function, they do indeed sometimes represent the same function. This thesis will also provide …

Global Domination Of Factors Of A Graph, Julie R. Carrington

Retrospective Theses and Dissertations

A factoring of a graph G = (V, E) is a collection of spanning subgraphs F₁, F₂, ... , F_k, known as factors into which the edge set E has been partitioned. A dominating set of a graph is a set of nodes such that every node in the graph is either contained in the set or has an edge to some node in the set. Each factor F_i is itself a graph and so has a dominating set. This set is called a local dominating set or LDS. An LDS of minimum …

Improving The Analytical Recovery Of Radiostrontium From Environmental Samples, Luz Selenia Acosta

Retrospective Theses and Dissertations

No abstract provided.

The Enhancement Of The Incineration Of Model Volatile Organic Solvents By The Use Of Hydrogen Peroxide As A Novel Oxidative Homogeneous Catalyst, Douglas James Tomlin

Retrospective Theses and Dissertations

No abstract provided.

Edge Contours, Donna J. Williams

Retrospective Theses and Dissertations

The accuracy with which a computer vision system is able to identify objects in an image is heavily dependent upon the accuracy of the low level processes that identify which points lie on the edges of an object. In order to remove noise and fine texture from an image, it is usually smoothed before edge detection is performed. This smoothing causes edges to be displaced from their actual location in the image. Knowledge about the changes that occur with different degrees of smoothing (scales) and the physical conditions that cause these changes is essential to proper interpretation of the results …

On K - Y - Insensitive Donimation, Teresa Haynes Rice

Retrospective Theses and Dissertations

A connected graph G is defined to be k-1-insensitive if the domination number 1(G) is unchanged when an arbitrary set of k edges is removed. The problem has been solved fork= 1. This Ph.D. dissertation focuses on finding extremal k-1-insensitive graphs on p nodes, fork~ 2. A graph is extremal if it has the minimum number of edges. Two subproblems are considered. The first, which has been solved completely, specifies that the same set of nodes dominates each graph obtained from G by removing k edges. The second requires only that the graph G be connected. This is a much …

Generating Multiple User Interfaces For Multiple Application Domains, Mahesh Hassomal Dodani

Retrospective Theses and Dissertations

This Ph.D. dissertation presents a classification scheme for User Interface Development Environments (UIDEs) based on the multiplicity of user interfaces and application domains that can be supported. The SISD, SIMD and MISD [S= Single, I= user Interface(s), M= Multiple, D= application Domain(s)] generator classes encompass most of the UIDEs described in the literature. A major goal of this research is to allow any user to develop a personalized interface for any interactive application, that is, the development of an MIMD UIDE.

Fundamental to the development of such a UIDE is the complete separation of the user interface component from the …

New Synthetic Transformations Of 1-Benzyl, 3,5-Dibromo, 1h-1,2,4-Triazole /C, Adam Michael Fivush

Retrospective Theses and Dissertations

This report details the study of the nucleophilic substitution of 1-benzyl-3,5-dibromo-lH-1,2,4-triazole. A variety of nucleophiles have been studied to date. The nucleophiles studied primarily fall into the categories of Phosphorous, Oxygen and Sul fur species. Some of the initially formed substitution products are thermally unstable and undergo unique rearrangements. The report describes the physical properties, 1H NMR, 13c NMR, IR and Mass spectra for all of the synthesized compounds. Possible mechanistic pathways are presented for the formation of the prepared compounds. Recommendations are made in order to suggest future research opportunities in this area.

Automatically Generating Syntax-Directed Editors For Graphical Languages, Farahangiz Arefi

Retrospective Theses and Dissertations

This research is concerned with the automatic generation of syntax-directed editors for graphical programming languages. A specification technique that is used to uniformly define graphical languages along with their syntax-directed editors is developed. The novel aspect of this specification technique, called a general graph transformation system, is that the graphical languages are described by specifying a family of editing operations. In this manner, a language is defined as a dynamic object which, by applying different editing operations, changes from one form to another, each form representing a sentence of the language. In order to demonstrate this process, the language of …

A Coprocessor Design For The Architectural Support Of Non-Numeric Operations, Timothy W. Curry

Retrospective Theses and Dissertations

Computer Science is concerned with the electronic manipulation of information. Continually increasing amounts of computer time are being expended on information that is not numeric. This is represented in part by modem computing requirements such as the block moves associated with context switching and virtual memory management, peripheral device communication, compilers, editors, word processors, databases, and text retrieval. This dissertation examines the traditional support of non-numeric information from a software, firmware, and hardware perspective and presents a coprocessor design to improve the performance of a set of non-numeric operations. Simple micro-coding of operations can provide a degree of performance improvement …

Some Optimally Adaptive Parallel Graph Algorithms On Erew Pram Model, Sajal K. Das

Retrospective Theses and Dissertations

The study of graph algorithms is an important area of research in computer science, since graphs offer useful tools to model many real-world situations. The commercial availability of parallel computers have led to the development of efficient parallel graph algorithms.

Using an exclusive-read and exclusive-write (EREW) parallel random access machine (PRAM) as the computation model with a fixed number of processors, we design and analyze parallel algorithms for seven undirected graph problems, such as, connected components, spanning forest, fundamental cycle set, bridges, bipartiteness, assignment problems, and approximate vertex coloring. For all but the last two problems, the input data structure …

I. Evaluation Of Iron Whiskers And Stainless Steel Microwaves As Catalysts For Ammonia Synthesis Ii. Hydrodechlorination Of Chloralkanes On Iron Whisker Catalysts, Diane Kaefer-Northcott

Retrospective Theses and Dissertations

This report consists of two parts. Part I concerns the evaluation of stainless steel microwires and iron whiskers, as catalysts for ammonia synthesis. Several comparison catalysts were also evaluated for their catalytic ability for ammonia synthesis. The effect of potassium promotion on filament and comparison catalysts was determined.

Part II concerns the evaluation of iron whisker catalysts with regard to their catalytic ability for their hydroechlorination fo chloroalkanes. The chloroalkanes that were used in the hydroechlorination reactions were carbon tetrachlorida, chloroform, methylene chloride, and 1, 1, 1-trichloroethane. The hydroechlorination reactions were conducted in the gas phase, either in the prsence …

A Relational Object-Oriented Management System And An Encapsulated Object-Oriented Programming System, Michael L. Nelson

Retrospective Theses and Dissertations

The purpose of the Relational Object-Oriented Management System (ROOMS) is to show that the relational database scheme is a viable approach for storing objectoriented data. ROOMS is designed so that it can be implemented in any object-oriented language with appropriate I/O commands, or added to any objectoriented database management system that allows userdefined collections of data. Various problems were encountered in developing ROOMS. While these problems have been solved, the best solution is to use the Encapsulated Object-Oriented Programming System (EOOPS) . EOOPS is based upon an inheritance scheme which preserves encapsulation. This encapsulated approach avoids the problems associated with …

Unexpected Products From The Reactions Of 1-(Bromodifluoromethyl)-2-(Bromoalkanes With Potassium Hydroxide,Characterization Of Some Gen-Difluorodienes And Attempted Syntheses Of Gem-Difluorocyclopropanes, Mariana Michael

Retrospective Theses and Dissertations

This research report discusses the reactions of CF2Br2 with various alkenes. Attempts to synthesize some gemdifluorocyclopropanes from alkenes and CF2x2 (X=Br, I) by modified Simmons-Smith procedures were Dehydrohalogenation reactions of some not successful. 1,3-dibromo-1,1- difluoroalkanes were conducted with potassium hydroxide or tributylamine. Heating cis or trans 1-(bromodifluoromethyl)- 2-bromocyclohexane with potassium hydroxide does not produce the expected gem-difluorodienes but instead gives the corresponding a,$ -unsaturated carboxylic acid. The mechanism for the productions of the various reaction intermediates from the reaction of the cyclic dibromide with potassium hydoxide is proposed. Experimental evidence supporting the proposed mechanism is presented. Gemdifluorodienes are isolated when …

Hardware Algorithms For Data Compression, N. Ranganathan

Retrospective Theses and Dissertations

Data compression is the reduction of redundancy m data representation in order to decrease storage and communication costs. Data compression techniques have been used in practice primarily through software implementations which fail to meet the speed and performance requirements of current and future systems. This Ph.D. dissertation presents a set of hardware algorithms for compression and decompression techniques and the results of detailed simulations performed to quantify the effects of incorporating such hardware in various architectural environments. A new pipelined algorithm for data compression applicable to static binary encoding schemes is presented. A fast hardware algorithm for decompression that uses …

The Reaction Of 2-Arylprop-1-En-3-Yltrimethylammonium Iodides With Sulfur Nucleophiles And Useful Synthetic Applications Of These Adducts, Steven J. Duranceau

Retrospective Theses and Dissertations

This report discusses research involving the reactions of 2-arylprop-1-en-3-yltrimethyl ammonium iodides with sulfur nucleophiles and the useful synthetic applications of the adducts formed. The present work may be subdivided into four sections: 1) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with benzenethiol; 2) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with the sodium salt of benzenesulfinic acid; 3) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with 2-mercapto-1-methyl imidazole; and 4) oxidation of 2-aryl-3-phenylthio-1-propenes and 2-aryl-3-phenylsulfonyl-1-propenes using sodium perborate. This report outlines the experimental conditions and procedures responsible for the synthesis of these products; in addition, this report describes the physical properties, NMR and IR spectra of …

Evaluation Of The Reduction Of The Nonadiabatic Hyperspherical Radial Equation To The First Order, Steven L. Carbon

Retrospective Theses and Dissertations

In this paper we examine the effectiveness of reducing the second order radial equation, of the hyperspherical coordinate solution to the two-electron Schrodinger equation, into a set of coupled first order linear equations as suggested by Klar. All results have been obtained in a completely nonadiabatic formalism thereby ensuring accuracy. We arrive at the conclusion that our application of the reduction process is in some way inconsistent and suggest a possible resolution to this anomaly.

Design And Performance Analysis Of A Relational Replicated Database Systems, Jon Gregory Hanson

Retrospective Theses and Dissertations

The hardware organization and software structure of a new database system are presented. This system, the relational replicated database system (RRDS), is based on a set of replicated processors operating on a partitioned database. Performance improvements and capacity growth can be obtained by adding more processors to the configuration. Based on designing goals a set of hardware and software design questions were developed. The system then evolved according to a five-phase process, based on simulation and analysis, which addressed and resolved the design questions. Strategies and algorithms were developed for data access, data placement, and directory management for the hardware …

Hydration Of Propylene To Isopropanol, Nehemiah Diala

Retrospective Theses and Dissertations

The hydration of propylene to isopropanol was investigated. The first part of this study concerned the direct hydration reaction in various liquid phase systems in the presence of sulfuric acid or p-toluenesulfonic acid. The second part in a two-stage process in which propylene was contacted with excess acetic acid to form isopropyl acetate; the ester was then hydrolyzed to isopropyl alcohol and acetic acid.

The Synthesis Of 2-Aryl-3-Fluoroalkoxy-1-Propenes And Some Potentially Useful Reaction Of These Systems, Joan E. Brown

Retrospective Theses and Dissertations

This report discusses research involving the fluoroalkoxylation of 2-arylprop-1-en-3-yltrimethylammonium iodides and the useful synthetic application of the adducts formed. The present work includes: 1) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with the sodium salt of 2,2,2-trifluoroethanol; 2) reactions of several fluoroalkoxy alcohols with 2-(4-bromophenyl)prop-1-en-3-yltrimethylammonium iodide; and 3) the oxidation of 2-(4-chlorophenyl)-3-(2,2,2-trifluoroethyoxy)-1-propene using the Lemieux/von Rudloff reagent. This report reveals the experimental conditions and procedures used as well as spectral and physical data of all new compounds synthesized. Explanation is offered for a possible mechanism for the formation of these compounds and recommendations for future research are given.

Preparation Of Geminal Diflourodienes, Antonio Landavazo

Retrospective Theses and Dissertations

This report discusses research involving the preparation of germinal difluorodienes. Free radical addition of dibromodifluoromethane to 1-hexene and cyclohexene was performed, followed by a double dehydrohalogenation to yield 1,1-difluoro-1,3-heptadiene and 3-(difluoromethylene)cyclohexene, respectively. NMR, IR, and mass spectral data were obtained and presented as groundwork for further research. A study comparing the free radical initiators, benzoyl peroxide and 2,2’-azobis-(2-methyl)proprionitrile (AIBN) was included, showing neither as ideal initiators for the free radical additions performed. The relative stabilities of the bromodifluoromethyl and the difluoroiodomethyl radicals were approximated. A Diels-Alder reaction of 1,1-difluoro-1,3-heptadiene with 4-phenyl-1,2,4-triazoline-3,5-dione produced the expected [4 + 2] cycloadduct in good …

The Slicing Extent Technique For Fast Ray Tracing, Sudhanshu Kumar Semwal

Retrospective Theses and Dissertations

A new technique for image generation using ray tracing is introduced. The “Slicing Extent Technique” (SET) partitions object space with slicing planes perpendicular to all three axes. Planes are divided into two dimensional rectangular cells, which contain pointers to nearby objects. Cell size and the space between slices varies, and is determined by the objects’ locations and orientations. Unlike oct-tree and other space-partitioning methods, SET is not primarily concerned with dividing space into mutually exclusive volume elements (‘voxels’) and identifying objects within each voxel. Instead, SET is based on analysis of projections of objects onto slicing planes. In comparison to …