Digital Commons Network^™

An Investigation Of Ibm Pc Computer Viruses Infection Rates And Types In A Western Australian Environment, Boon Guan Lee

Theses : Honours

In recent years computer viruses have become increasingly significant as a form of computer abuse. By virtue of their reproductive capability, computer viruses can have cumulative and potentially catastrophic effects to the many people who use those affected computers. There is a growing concern in the computing community about these forms of electronic vandalism. This concern arises from the possible damage to stored information on which the work depends and the ensuing disruption of the work-place. Although the vandalism or purposeful abuse by introducing computer viruses to computer systems was originally mainly an American experience, research reports published by the …

Electromagnetic Wave Scattering From Magnetic Fluctuations In Tokamaks, L. L. Vahala, G. Vahala, N. Bretz

Electrical & Computer Engineering Faculty Publications

Cross sections are calculated for electromagnetic wave scattering and mode transformation from magnetic and density fluctuations in a homogeneous plasma. For the special case of scattering perpendicular to the magnetic field, density fluctuations scatter ordinary to ordinary and extraordinary to extraordinary modes-but cannot transform these modes. On the other hand, magnetic fluctuations perpendicular to the field can transform modes but cannot scatter on a single branch. For incident frequencies on the order of the electron plasma frequency or gyrofrequency, the cross sections for scattering and transformation due to field and density fluctuations have a similar value. Estimates are given for …

Restoring Faith In Natural Resource Policy-Making: Incorporating Direct Participation Through Alternative Dispute Resolution Processes, Kaleen Cottingham, University Of Colorado Boulder. Natural Resources Law Center

Books, Reports, and Studies

8 p. ; 28 cm

Plasma As A High-Charge-State Projectile Stripping Medium, G. D. Alton, R. A. Sparrow, Ronald E. Olson

Physics Faculty Research & Creative Works

The classical trajectory Monte Carlo model has been used to computationally study the charge-state distributions that result from interactions between a high-energy, multielectron projectile and neutral and fully ionized targets. These studies are designed to determine the properties of a plasma for producing highly stripped ions as a possible alternative to gas and foil strippers that are commonly used to enhance the charge states of energetic ion beams. The results of these studies clearly show that a low-atomic-number, highly ionized plasma can yield higher charge states than a neutral target of the same density. The effect is principally attributable to …

The Application Of Liquid Junctions For Characterization Of Semiconductor Materials, Wu-Mian Shen

Dissertations, Theses, and Capstone Projects

In this study, liquid junctions were used to characterize silicon and silicon subjected to various reactive ion etching (RIE); surface optimization of CuInSe{dollar}\sb2{dollar}; and photo-modification of InSe. Impedance spectroscopy and modulation spectroscopies such as electrolyte electroreflectance (EER), photoreflectance (PR), and photoreflectance in the presence of electrolyte (EPR) were the major methodologies that were used for investigating the dielectric properties of the semiconductors and their interface with the ambients. It was shown that the above experimental techniques provide information about the flat-band potential, doping density, Fermi level pinning, the density and distribution of surface states, energy gap and broadening parameter related …

Denitrification In The Elk Valley Aquifer, Northeastern North Dakota, Gale G. Mayer

Theses and Dissertations

Biological denitrification controls nitrate distribution in the Elk Valley aquifer, which underlies approximately 725 square kilometres of northeastern North Dakota and provides drinking water for farms and rural communities in the area. Increased irrigation has raised concerns over potential contamination from agricultural practices. The purpose of this study was to establish the role of biological denitrification in minimizing concentration and distribution of nitrate and to determine the effect irrigation practices have on groundwater flow and nitrate distribution in the saturated zone.

The aquifer is unconfined and consists of up to 20 metres of glacial outwash and deltaic shale-rich sand deposits. …

Desorption Hysteresis In Five Ion Exchanged Montmorillonites, Jerry Paul Fairley

UNLV Theses, Dissertations, Professional Papers, and Capstones

It is generally believed that the formation of recalcitrant (slowly desorbing) fractions of volatile organic compounds (VOCs) in soils is due to diffusion of compounds to sorption sites inaccessible to bulk fluid. The exact nature of these sites, however, is not well understood. In clay minerals, researchers favor two probable areas for the storage of persistent contamination; sites between the clay lamella, or sites with clay particle aggregates.

To test the hypothesis that recalcitrant fractions are formed in interlamellar spaces, a Na/Ca Montmorillonite (Smectite) was ion exchanged with five different cations (K⁺, Na⁺, Ca⁺, …

Editing Digital Audio Using A Perceptual Model, J. Mark Goode

Theses

In this paper we describe an intelligent system used to aid an audio recording producer in the selection of edit points in a musical sequence. It is possible to make meaningful recommendations concerning auditory input data without the ability to fully classify that data or interpret all outside goals. Perceptual modeling of the auditory input can allow sufficient reasoning ability for an intelligent system to be of use editing digital audio. To create a perceptual model, the information which can be extracted by the ear is embodied in several expert sections which communicate with a rule based decision maker via …

Unix And Security: The Influences Of History, Eugene H. Spafford

Department of Computer Science Technical Reports

No abstract provided.

Biomass Conversion Of Solid-Waste (Newsprint) Into A Clean Fuel (Ethanol) By Enzymic Hydrolysis And Fermentation, Nimesh V. Gandhi

Theses

A feasibility study has been performed with two bioprocesses for conversion of newsprint waste to an environmentally safe fuel (ethyl alcohol) and carbon dioxide.

The following areas were investigated to accomplish this task: one hour pretreatment of newsprint by attrition, saccharification of paper slurry to glucose by cellulase and cellobiase, effects of pH, temperature and concentration of enzymes on conversion of paper to sugar, fermentation of glucose to ethanol and carbon dioxide by immobilized yeast, and simultaneous saccharification and fermentation of paper to ethanol and carbon dioxide using enzymes and immobilized yeast.

Results indicate that the enzymic hydrolysis of newsprint …

The Effects Of Oxygen Tension On Nitrate Reduction By Pseudomonas Isolate, Hao-Jan Hsing

Theses

It is a generally accepted concept that nitrate reduction only occurs under anaerobic conditions. Oxygen inhibits denitrification. However many studies of nitrate reduction under low oxygen tension have shown what has been called aerobic denitrification. This project examines the process of aerobic denitrification.

Oxgyen affects cell growth and the amount of nitrate utilized. When oxygen is absent, the cell growth rate is lower and nitrate utlization is higher then when oxygen is present.

Nitrate is reduced to nirite under anaerobic conditions. Nitrite accumulation did not continue increase. But increased then decreased producing a "Z" shaped graph when plotted.

Visualization Of Four Dimensional Space And Its Applications (Ph.D. Thesis), Jianhua Zhou

Department of Computer Science Technical Reports

No abstract provided.

Ccis Networking - December 1991, Nova University

CCIS Networking / SCIS Networking magazines

No abstract provided.

Recycling: Knowledge, Demographic & Motivational Factors Which Differentiate Behavior, David Ducoff

Masters Theses & Specialist Projects

This study focuses on motivation -Involved in recycling behavior among residents of Muhlenberg County, Kentucky. Knowledge of recycling and how it was acquired, and the variables of environmental concern, economic incentive and the peer pressure were compared so that behavior could be distinguished that separated recyclers from nonrecyclers. Talcott Parsons' work in action theory and George Homans' work in exchange theory provide the theoretical foundation for my study. The research was approached in a qualitatively based design with interviews of twenty area residents. Demographic factors of age, sex, religious affiliation, church attendance, education and income of respondents were solicited. In …

The Calendar - December 1991, Nova University

The Calendar

No abstract provided.

Specifying Interdatabase Dependencies In A Multidatabase Environment, Marek Rusinkiewicz, Amit P. Sheth, George Karabatis

Kno.e.sis Publications

The problem of interdatabase dependencies and the effect they have on applications updating interdependent data are addressed. A model that allows specifications of constraints among multiple databases in a declarative fashion is proposed. The separation of the constraints from the application programs facilitates the maintenance of data constraints and allows flexibility in their implementation. It allows investigation of various mechanisms for enforcing the constraints, independently of the application programs. By grouping the constraints together, it is possible to check their completeness and discover possible contradictions among them. The concepts of polytransactions, which use interdatabase dependencies to generate a series of …

Structured Hypermedia Application Development Model (Shadm): A Structured Model For Technical Documentation Application Design, Peter W. Cassell

Theses and Dissertations

This research was conducted to determine how a Royal Australian Air Force technical maintenance publication could be transformed into a task oriented hypermedia application and to develop a model that could be used for future similar transformations. The model was developed following in-depth analysis of the existing USAF F-15E maintenance publication set and validation was conducted using a prototype developed in HyperWriter, a commercial hypermedia product. The prototype model was based around the performance of three maintenance tasks on an aircraft sub-subsystem and incorporated online user access to the necessary support data for task completion. Publication managers, producers, and users …

An Event Driven State Based Interface For Synthetic Environments, Mark J. Gerken

Theses and Dissertations

Previous research at the Air Force Institute of Technology (AFIT) has produced synthetic environments using head mounted displays (HMDs) and hand measurement devices. This thesis is a continuation of AFIT synthetic environment research. Hand measurement data from a VPL DataGlove is combined with hand orientation and translational data to define a set of valid gestures. These gestures form the basis of an input language for class of finite automata known as finite state machines. Using the input symbols from this language, the user may define a finite state machine which associates a stream of input symbols with one or more …

A Cache Design To Exploit Structural Locality, Curtis M. Winstead

Theses and Dissertations

A design and VHDL implementation of a content-addressable memory (CAM) to exploit structural locality is the subject of this research. The concept of structural locality is that memory locations are referenced in the same order as they were previously referenced. Therefore, if memory locations that exhibit structural locality can be made available to the CPU (Center Processing Unit) through a fast data store, an increase in speed of the computer system can be realized. The CAM's purpose is to store memory references in the order they were used by the CPU and prefetch these locations to a smaller on- chip …

A Rigorous Uniform Diffraction Analysis Of The Electromagnetic Scattering From Impedance Edges And Junctions, Joseph C. Fortney

Theses and Dissertations

This paper investigates the scattering from impedance strips and impedance-loaded conducting strips. The impedance strips are analyzed using Senior's impedance half plane formulation. Once the primary diffraction from the impedance half plane is presented, it is used to develop multiple diffraction mechanisms on an impedance strip. The scattering from impedance-loaded strips are analyzed using Maliuzhinets' impedance wedge formulation. The primary diffraction mechanism from an impedance wedge is used to develop the multiple diffractions on an impedance double wedge. The multiple diffractions on both types of strips are developed using the Extended Spectral Ray Method. Sample calculations are made for impedance …

Real Imagery As A Three Dimensional Display, Juan C. Echeverry

Theses and Dissertations

This research effort implemented two 3-D display designs to assess their performance and effect on an observer's depth perception. Both 3-D displays produced real images for the observer to view. The first display setup combined a lens relay with a two concave mirror projector. The second display setup combined the two concave mirror projector with a diffuser. The lens relay/ two concave mirror projector combination was successful in imaging a source from the CRT to a point in space above the two mirror system. The problem was that the observer could not assess the image location by just looking at …

Reducing Requirements Errors Through The Use Of Computer-Aided Software Engineering (Case) Tools And During Requirements Analysis, Marvin B. Key Jr.

Theses and Dissertations

This study investigated whether using CASE tools in the requirements analysis phase of software development reduced the software coding errors attributable to requirement analysis. A survey of the population gathered data as to the current practices and efforts in the use of CASE tools. The data was gathered in two groups: a control group and a sample group. The data was analyzed by group and in various combinations to obtain a greater understanding into population trends and tendencies. The results of the research indicate that the Air Force does not use CASE tools to any great extent. Also, error and …

Selected Studies On Certain Iron Sandwich Complexes, Mashitah M. Yusoff

Masters Theses

In these studies, the synthesis of [2.3](1,3)cyclopentadiendoparacyclophane was attempted. Like ferrocene and [2.2]paracyclophane, it is expected to exhibit transannular π-electronic interaction throughout its molecular structure and therefore, one dimensional semiconductivity.

The preparation of dialkylferrocenes had resulted in complex inseparable mixtures. Due to the fluxional nature of its intermediates, their conversion to stable Diels-Alder adducts would facilitate analysis. In this project, certain Diels-Alder adducts of bis-cyclopentadienyliron dicarbonyl intermediates were prepared for analysis.

Very few transition metal complexes of pyrrole are currently known. [2.2](2,5)Pyrroloparacyclophane was perceived to be stable especially as a part of an iron sandwich complex. The final phase …

Knowledge-Based Systems Approach For Offshore Safety Training, B. S. Lee, Venky Shankararaman

Research Collection School Of Computing and Information Systems

A number of training methods has been used within the offshore industry to impart safety knowledge and safe operating skills. In this paper a Knowledge-Based Safety Training architecture is proposed. The architecture uses both expert system and hypertext methods and is also applicable to plants other than offshore platforms. Special attention is given to the types of knowledge dealt with in safety training and how to represent this knowledge and teach it using various teaching strategies.

Fabricating Magnetic Co-Ni-C Thin-Film Alloys By Organometallic Chemical Vapor Deposition, Yoon-Gi Kim, Dongjin Byun, C. Hutchings, Peter A. Dowben, H. Hejase, K. Schröder

Peter Dowben Publications

We have deposited Co_xNi_y^-C films with a variety of compositions to verify dependence of the saturation magnetization on the composition. These experiments suggest that we can produce Co_xNi_y^-C films with a variety of magnetic properties. The Co_xNi_y^-C films were fabricated by ultraviolet decomposition of cobaltocene and nickelocene. We demonstrated that the photolytic decomposition of these metallocenes produces cyclopentadienyl (C₅H₅) species, consistent with recent studies of the energetics of the ligand metal bonds.

Sputtering Pressure Effect On Microstructure Of Surface And Interface, And On Coercivity Of Co/Pt Multilayers, Ping He, William A. Mcgahan, S. Nafis, John A. Woollam, Z.S. Shan, Sy_Hwang Liou, F. Sequeda, T. Mcdaniel, H. Do

Sy-Hwang Liou Publications

Thin Co/Pt multilayers were prepared on Si and glass substrates by sputtering with Ar pressures ranging from 2.5 to 15 mTorr. The bilayer structure of the samples was Co(3 Å)/Pt(15 Å)×17, and all samples had the easy axis of magnetization perpendicular to the sample surface as determined with a SQUID magnetometer. All samples retained the layered structure, as revealed by low-angle x-ray diffraction. In addition, diffraction peaks due to the formation of Co-Pt compounds (presumably at the interfaces between Co and Pt) were identified. The coercivity of samples changed from about 400 Oe for films deposited at low Ar sputtering …

Studies Of Domain Dynamics In Amorphous Dy/Fe Multilayers, Roger D. Kirby, J.X. Shen, Z.S. Shan, David J. Sellmyer

Roger Kirby Publications

Compositionally-modulated Dy/Fe films were prepared by dc magnetron sputtering onto glass substrates. For this series of samples, the Dy thickness was fixed at 5 Å, while the Fe thickness was varied from 4 to 6 Å. To study the magnetization reversal, the samples were first saturated. The magnetic field was then reversed to a value near the coercive field, and the Kerr rotation was measured as a function of time after reversal. We interpret our results in terms of the model of domain reversal first described by Fatuzzo for ferroelectrics. For some Fe thicknesses, we found that the reversal process …

Temperature And Layer-Thickness Dependencies Of Kerr Rotation In Dy/Co Multilayers, Z.S. Shan, J.X. Shen, Roger D. Kirby, Sy_Hwang Liou, David J. Sellmyer

Sy-Hwang Liou Publications

Amorphous Dy/Co multilayers with the individual layer thickness between 4 and 10 Å in steps of 0.5 to 1 Å were studied systematically over the temperature range 100–300 K. The Kerr rotation increases as temperature decreases, or as Co content increases and the coercivity increases both in the low temperature region and in the vicinity of the compensation point. These characteristics were analyzed in terms of simple models of the magnetic structure and magnetization reversal.

The Calendar - November 1991, Nova University

The Calendar

No abstract provided.

A Common Application Model For Interfacing With Advanced Program To Program Communication/Vm, Joseph Viviano Jr.

Theses

The Merrill Lynch data processing environment is composed of a conglomeration of applications which reside on various platforms. LAN and minicomputer based applications coexist with those making their home in the mainframe arena. Unfortunately, coexistence does not imply cooperation, data uniformity, data centralization or coordinated application development. Within the Merrill Lynch mainframe arena alone there are two operating systems which reside across several computing complexes, MVS (Multiple Virtual Storage) and VM (Virtual Machine). Critical business applications and data are unique to each of these environments. The problem lies in the need for cooperative processing and sharing of distributed data among …