Digital Commons Network^™

Continuous Monitoring Of Volatile Organic Compounds Using Microtrap Based Gas Chromatographic Systems, Yonghua Xu

Dissertations

Continuous analysis allows a representative portion of a sample to flow continuously through an analytical instrument, which gives analytical information with little or no delay in time. A microtrap is a small diameter tube packed with adsorbents in series. When a gaseous sample containing volatile organic compounds (VOCs) flows through the microtrap, the VOCs can be trapped selectively by adsorbents. Then a pulse of electrical current is applied to the microtrap. This rapid heating results in a desorption that can act as a sharp injection for GC separation. Thus the microtrapped sample is the total amount of VOC present in …

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 …

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 …

Ground Water Movement Through The Highly-Fractured Crystalline Core Of A Large-Scale, Foreland Uplift, Roy Al Gorge Arch, South-Central Colorado, Timothy L. Clarey

Dissertations

The objectives of this study were twofold: ( 1) to examine the well-exposed, basement core of the Royal Gorge arch as a large-scale, field test of ground water flow through a fractured, crystalline, aquifer system; and (2) to devise a method to more accurately determine the direction of maximum aperture of a fractured aquifer through structural and hydrogeologic analysis.

The recognition of a preferred direction of maximum aperture in a fractured aquifer remains an important hydrogeologic consideration because flow through a fracture is proportional to the cube of the aperture width. Previous studies of hydraulic directions using fracture orientation techniques …

Adolescent Students At Risk: The Roles Of Stress, Distress, And Coping, Jennifer Massicotte

Dissertations

Male and female adolescents who reported recent suspension/ threats of suspension or academic failure were compared to male and female adolescents who did not report these two variables of dropping out on three measures--the discrete negative uncontrollable events experienced (LEQ-A, Garmezy, Masten, & Tellegen [1985]), the level of distress (GHQ-30, Goldberg [1972]), and the types of coping skills used (A-COPE, Patterson & McCubbin [1983]). Native and non-Native at risk for suspension and academic failure rates were also compared using archival data from a community mental health survey of 714 adolescents (36 Native) attending high school in Northern Ontario.

Native adolescents …

An Investigation Of The Relationship Between Homework Assignments In Counseling And Perceptions Of Specific Counselor Characteristics, George T. Starrett

Dissertations

This study investigated the relationship between the use of homework assignments in counseling and perceived counselor characteristics. An analog design was used with 60 introductory psychology students serving as subjects. One of two video taped counseling vignettes was presented to the two subject groups. The counselor depicted in the control group tape did not use homework assignments, while homework assignments were used by the counselor depicted in the treatment group tape.

After viewing the one of the two tapes the subjects completed the Counselor Evaluation Scale (CES) and the Counselor Rating Form-Short (CRF-S) to provide ratings of each of the …

The Experiences Of Mid-Career Elementary Teachers, Susan H.L. Johnston Edd

Dissertations

The demographics of the teaching population in British Columbia indicate a significant number of teachers in mid career. Their cares, concerns, and interests dramatically influence educational activity in the province. The experiences of these educators lie within a context of major restructuring of the entire provincial school system and substantive educational change mandated by the government of British Columbia. Using a phenomenological approach, this study explores the experiences of seven, mid-career, elementary school teachers in one British Columbia school district; investigates how these teachers experience system-wide, mandated, educational change; and suggests implications of these understandings for leadership practice. During three, …

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 …

Androgen Receptors In The Hippocampus: Localization, Autoregulation, And Modulation Of Gene Expression In The Adult Male Rat, Janice E. Kerr

Dissertations

No abstract provided.

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.

A Study Of The Concomitant Problems Facing Most Of The "At-Risk" African American Students In The Benton Harbor Elementary School System: A Case For An Alternative Model, Simon M. Honore

Dissertations

Problem

It would appear that the problem of school truancy, retention, and subsequent academic failure is a major educational crisis which puts most of the African American students at risk in the Benton Harbor area schools.

Purpose

The purpose of this study has been to determine the concomitant educational problems facing the "at-risk" African American students in the Benton Harbor Elementary School System and to suggest positive changes through an alternative model.

Results

The results of the survey indicated that approximately 90-95% of Benton Harbor educators agreed to changes. Administrators and teachers strongly agreed that the recommendations, based on the …

Photophysics And Photochemistry Of Carbocations, Maria R. Valentino

Dissertations

No abstract provided.

Critical Attributes Of Teachers Who Have Become Practitioners Of Authentic Assessment, Bernadette Meisenheimer

Dissertations

No abstract provided.

The American Bible College: An Eye To The Future, Larry J. Davidhizar

Dissertations

No abstract provided.

An Analysis Of Reading, Writing, And Language Development In An Integrated Intermediate School Program, Rosa Antonietta Rizzato

Dissertations

No abstract provided.

The Anchor School: A Rationale For Catholic Education In The Archdiocese Of Chicago Through An Historical Review Of The Financial Status Of Nine Parishes Of The Archdiocese Of Chicago Before And After Consolidation, Dennis M. Composto

Dissertations

No abstract provided.

Organizational Models In Developmental Education: A Taxonomy, Gail D. Lenn Dantzker

Dissertations

No abstract provided.

The Development, Molecular Characterization And Application Of A Model Stratum Corneum Lipid System, Rita M. Hatfield

Dissertations

No abstract provided.

Mysticism, Logic And The Metaphysics Of Time: Henri Bergson's Method And Its Implications For Contemporary Philosophy, Gregory A. Clark

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.