Digital Commons Network^™

A Full Wave Method For Rough Surface Scattering Using Fictitious Current Distributions, Anthony A. Triolo

Dissertations

Rough surface scattering is a current topic of interest in many diverse fields. But, despite its importance, the two most widely used solution methods, the Kirchhoff and first order perturbation methods, are valid only for a restricted range of surface types. There is a large range of surface statistics for which neither of these theories is valid. There are purely numerical solutions to the problem, i.e., the integral equation technique and FDTD method, but these methods require a prohibitively large amount of computer time and storage space for use in practical applications. A full wave method has been introduced by …

Reduction Of Inertia-Induced Forces In A General Spatial Mechanism, Sahidur Rahman

Dissertations

A computer-aided design procedure has been developed for minimizing the adverse effects of the inertia-induced forces by optimum mass redistribution amongst the links of high speed general spatial linkages. The evaluation of an optimality criterion for the mass redistribution of the mechanism will be carried out with the aid of a quadratic programming technique. This has been found to be successful in minimizing inertia induced forces and torques. The validity of the optimization procedure will be demonstrated by application to one kind of spatial linkage.

No literature has been found on the balancing of a general spatial mechanism, since its …

Discrete Element Modeling Of Dry Granular Material Using A Massively Parallel Supercomputer, David W. Washington

Dissertations

It is the state-of -the-art within Geotechnical Engineering to model soils as systems of particles rather than using the traditional continuum approach. Simulating these systems of particles for geotechnical boundary value problems results in systems which are of necessity large, motivating the application of massively parallel supercomputers. This thesis pursues such an approach.

The following work describes numerical experiments using a Discrete Element Method (DEM) paradigm for soils (Trubal) together with massively parallel computers with Single Instruction Multiple Data (SIMD) architecture. The discrete element method describes the behavior of granular assemblies using the classical mechanics of discrete bodies. The computational …

Integrating Knowledge And Action: A Study Of Leadership In The Development Of Master's Degree Programs In Liberal Studies, Janet L. Littrell Edd

Dissertations

Master's degree programs in liberal studies (MALS programs) have proliferated in the United States over the past twenty years. Studying the leadership relationships that faculty and administration form during the MALS program development process provides insight into how non-traditional graduate programs may be developed in the future. The purposes of the study were to investigate the development of MALS programs, and to examine the leaders and followers who successfully advanced the MALS program development agenda. The specific objectives of the study were (1) to examine the theoretical bases and curricular frameworks of MALS programs; (2) to explore how individuals and …

The Public Administrationist As Civic Shaman: The Self-Reflective Integrator Of Policy Frames Of Reference And Social Character, Phillip A. Brown

Dissertations

This study discusses the discipline of Public Administration and the Public Administrationist in relation to policy frames of reference and social character. The relationship of policy frames of reference and social character is the basis for public trust As the American political system becomes more and more fragmented, public administrationists, sometimes by default, become the trustees for safeguarding the public trust.

The concept of policy frames of reference, as it evolves in this discussion, refers to the ability of the public administrationist to understand the interactions of changing issues impacting on the interactions of changing issues, or quantum thinking. Social …

On The Adaptive Multi-Stage Detector For Cancellation Of Multiuser Interference In Cdma Wireless Communication Systems, Nadir Sezgin

Dissertations

The classical multiple access techniques such as Frequency Division Multiple Access (FDMA) and Time Division Multiple Access (TDMA) schemes are band limited in terms of their capacity to be used for mobile radio communication. Recent developments in the area of digital signal processing, makes Code Division Multiple Access (CDMA) as a possible solution to the demand of capacity for the mobile radio communication. The capacity of CDMA is limited by multiuser interference, that is the interference from the other users.

The goal of this dissertation is to improve the multiuser CDMA detector with high Bit Error Rate (BER) performance, low …

Real Time Control Of Nonlinear Dynamic Systems Using Neuro-Fuzzy Controllers, Amitava Jana

Dissertations

The problem of real time control of a nonlinear dynamic system using intelligent control techniques is considered. The current trend is to incorporate neural networks and fuzzy logic into adaptive control strategies. The focus of this work is to investigate the current neuro-fuzzy approaches from literature and adapt them for a specific application. In order to achieve this objective, an experimental nonlinear dynamic system is considered. The motivation for this comes from the desire to solve practical problems and to create a test-bed which can be used to test various control strategies. The nonlinear dynamic system considered here is an …

Investigation Of Dynamic Friction In Lubricated Surfaces, Hanuman Rachoor

Dissertations

The research reported in this dissertation is concerned with the development of friction models for lubricated contacts. A few analytical models have been developed to investigate the friction under dynamic velocity conditions. In this study, two different tribological situations such as conformal and non-conformal contacts have been chosen. Friction modeling covers boundary, mixed and full fluid film friction regions. A new theory based on the elastic properties of the surface materials, and fluid film properties of the lubricant at the contact has been developed to determine the dynamic friction in boundary, mixed and full hydrodynamic lubrication regions. In the full …

Adaptive Space-Time Processing For Wireless Communications, Xiao Cheng Bernstein

Dissertations

Adaptive space-time processing techniques have been found to increase the capacity of two major, multiple-access wireless communication systems: Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA).

In an IS-54 TDMA system, the frequency re-use factor has to be set to 7 so that cells with the same spectrum are separated far enough to meet a required carrier-to-interference ratio (CIR). Space processing uses multiple antennas which, in turn, provide alternative signal paths in order to cancel interferences and combat multipath fading. We have proposed the eigencanceler method and have reviewed the theoretical optimum combining and the feasible direct …

Identifying And Exploiting Concurrency In Object-Based Real-Time Systems, Guohui Yu

Dissertations

The use of object-based mechanisms, i.e., abstract data types (ADTs), for constructing software systems can help to decrease development costs, increase understandability and increase maintainability. However, execution efficiency may be sacrificed due to the large number of procedure calls, and due to contention for shared ADTs in concurrent systems. Such inefficiencies are a concern in real-time applications that have stringent timing requirements. To address these issues, the potentially inefficient procedure calls are turned into a source of concurrency via asynchronous procedure calls (ARPCs), and contention for shared ADTS is reduced via ADT cloning. A framework for concurrency analysis in object-based …

On Optimal Design And Applications Of Linear Transforms, Mehmet V. Tazebay

Dissertations

Linear transforms are encountered in many fields of applied science and engineering. In the past, conventional block transforms provided acceptable answers to different practical problems. But now, under increasing competitive pressures, with the growing reservoir of theory and a corresponding development of computing facilities, a real demand has been created for methods that systematically improve performance. As a result the past two decades have seen the explosive growth of a class of linear transform theory known as multiresolution signal decomposition. The goal of this work is to design and apply these advanced signal processing techniques to several different problems.

The …

On The Optimization Problems In Multiaccess Communication Systems, Gangsheng Wang

Dissertations

In a communication system, the bandwidth is often a primary resource. In order to support concurrent access by numerous users in a network, this finite and expensive resource must be shared among many independent contending users. Multi-access protocols control this access of the resource among users to achieve its efficient utilization, satisfy connectivity requirements and resolve any conflict among the contending users. Many optimization problems arise in designing a multi-access protocol. Among these, there is a class of optimization problems known as NP-complete, and no polynomial algorithm can possibly solve them. Conventional methods may not be efficient arid often produce …

Anaerobic Digestion And Acid Hydrolysis Of Nitrocellulose, Fong-Jung Tai

Dissertations

In this investigation, studies were conducted to evaluate the biodegradation of nitrocellulose in anaerobic batch reactors with and without the supplemental carbon inducers, such as cellulose, cellobiose, and lactose. Results from the anaerobic study show that degradation of nitrocellulose alone is difficult and that nitrocellulose degradative enzymes could be induced by the three inducers tested. As high as 48.91% conversion could be obtained at Cellulose/Nitrocellulose ratio of 1 to I. Studies also indicated that type 20 and 50 celluloses would be more effective and optimum pH was about 6.4 in biodegradation of nitrocellulose. Three testing systems, namely, single-stage, two-stage, and …

An Investigation Of The Mechanism Of Advanced Oxidation Processes (Aop) Involving Free Radicals And Charged Species., Yaw-Kuen Lin

Dissertations

Hydrogen peroxide is a key component in Advanced Oxidation Processes (AOP). Its decomposition at different pH conditions has been studied and some interesting results were observed. When the pH value of hydrogen peroxide solution is less than 9, its rate of decomposition is independent of pH. On the other hand, in the pH range of 9-12.6, its rate of decomposition increases as pH increases, and goes through a maximum value then suddenly decreases with respect to pH. A reaction kinetic model with three rate constants in the form of beta probability function was used to describe the experimental data of …

A Case Study Of The Change Process In An Urban Public School As Teachers React To Mandated Change, Susan Kurland

Dissertations

No abstract provided.

A Return Of Christianity: The Christian Education Of Korean- American Children In The Chicago Area By Parents, 1965-1995, Mark Yoon

Dissertations

No abstract provided.

Chicago Public Schools March Off To War: Participation Of The City Public Schools In The Second World War: 1941-1945, Joan L. Rog

Dissertations

No abstract provided.

Relationships Between The Expression Of Genes Involved In The Regulation Of Apoptosis And Cell Death Induced By Nitrogen Mustard In Human Colon Carcinoma Cell Lines, Greggory Bernard Herbert

Dissertations

No abstract provided.

Children's Assignment Of Intentionality To People, Animals, Plants, And Objects: Challenges To Theory Of Mind And Animism, Elizabeth Nebeker Szendre

Dissertations

No abstract provided.

San Antonio V. Rodriguez & The Next Twenty Years Of State Court Cases, Mary J. Long

Dissertations

No abstract provided.

Women Mentoring Women: A Phenomenological Study, Jacqueline Jachym Fitzpatrick Edd

Dissertations

The purpose of this study was to examine the lived experience of ten business and professional women who have experienced a mentoring relationship as a mentor or protegee with another woman, to understand the essence of their mentoring experience, and to know more about their participation as mentors. This study began with the assumption that women who experienced mentoring whether from women or men would be active mentors themselves. However, the data reveal an important contradiction.

Since women are entering the business and professional ranks of the work force at an increasing pace, there are greater numbers of women who …

An Exploratory And Descriptive Analysis Of Total Quality Management And Professional Nursing Education To Meet Healthcare Needs, Barbara Mary Huspen Gaffke

Dissertations

No abstract provided.

Sowing The American Dream: Consumer Culture In The Rural Midwest, 1865-1900, David Blanke

Dissertations

No abstract provided.

An Investigation Of The Prior Academic Experiences, Family Characteristics, Undergraduate Experiences And Postgraduate Plans Of Gifted Black College Students, Joyce Maria Scott

Dissertations

No abstract provided.

A Structural Analysis Of A Social-Cognitive Model Of Career Interests, Paul Anthony Gore

Dissertations

No abstract provided.

Perceptions Of The Teaching Profession Among Academically Successful Students Of Selected Affluent High Schools In Cook And Dupage Counties Of Illinois, Stephen Heller

Dissertations

No abstract provided.

Susa Young Gates 1856-1933: Educator, Suffragist, Mormon, Patricia A. Lynott

Dissertations

No abstract provided.

A Descriptive And Exploratory Case Study Of The Evolution Of Intercollegiate Athletics And Education At Loyola University Chicago: 1922-1994, Thomas G. Hitcho

Dissertations

No abstract provided.

A Study Of Active Participation Instructional Strategies Increasing Student's Higher Order Thinking Skills, Scottie J. Griffin

Dissertations

No abstract provided.

The Acceptance Of Computers By Administrative Leadership At Baker College, William Mccormick Luczyk

Dissertations

Procedures for recording information, capturing data for distribution to faculty, students, and other campuses was often being done manually by administrators at Baker College. Because of either a lack of access, or a lack of knowledge and training, simple computer data searches, spreadsheets, and telecommunications were difficult to accomplish and in some cases could not be done by Baker College administrators.

The sample population for this research consisted of forty-six males and forty-seven females for a total of ninety-three existing Baker College administrators, from nine campuses of varying size, throughout the State of Michigan. Data in the areas of computer …