Digital Commons Network^™

Oblivious Data Hiding : A Practical Approach, Husrev T. Sencar

Dissertations

This dissertation presents an in-depth study of oblivious data hiding with the emphasis on quantization based schemes. Three main issues are specifically addressed:

1. Theoretical and practical aspects of embedder-detector design.

2. Performance evaluation, and analysis of performance vs. complexity tradeoffs.

3. Some application specific implementations.

A communications framework based on channel adaptive encoding and channel independent decoding is proposed and interpreted in terms of oblivious data hiding problem. The duality between the suggested encoding-decoding scheme and practical embedding-detection schemes are examined. With this perspective, a formal treatment of the "processing" employed in quantization based hiding methods is presented. In …

Fabrication And Characterization Of Microcrystalline Silicon Solar Cells, Liwei Li

Dissertations

In this study, single junction p-i-n μc-Si:H solar cells were prepared using plasma of silane diluted by hydrogen in a low-cost, single chamber, non-load-locked RF-PECVD system. Direct structural characterization of μc-Si:H solar cells, rather than stand-alone films, was conducted using Raman Spectroscopy, XRD, and AFM. Strong correlations among device deposition, i-layer structural properties, and device performance have been established. With such correlations, critical issues in fabricating low-cost, large-scale, high performance μc-Si:H solar cells were identified.

The critical importance of seeding processes in determining the microstructure of μc-Si:H i-layers and performance of μc-Si:H solar cells has been demonstrated. Using …

Studies On Improved Integrated Membrane-Based Chromatographic Process For Bioseparation, Yanke Xu

Dissertations

To improve protein separation and purification directly from a fermentation broth, a novel membrane filtration-cum-chromatography device configuration having a relatively impermeable coated zone near the hollow fiber module outlet has been developed. The integrated membrane filtration-cum-chromatography unit packed with chromatographic beads on the shell side of the hollow fiber unit enjoys the advantages of both membrane filtration and chromatography; it allows one to load the chromatographic media directly from the fermentation broth or lysate and separate the adsorbed proteins through the subsequent elution step in a cyclic process.

Interfacial polymerization was carried out to coat the bottom section of the …

The Use Of A Water Quality Model To Evaluate The Impacts Of Combined Sewer Overflows On The Lower Hudson River, Wen-Pin Shu

Dissertations

CSO discharges have long been recognized as a significant source of water pollution. While many sources of water pollution have been controlled over the past 20 years, CSOs continue to be a main environmental concern in several areas, especially in old cities. In the past, most CSO research focused on the CSO control processes, including floatables and suspended solids removal. Few studies have been conducted in the area of the impacts of CSO discharge on the receiving water quality. To achieve this purpose, a powerful water-modeling tool, WASP 6.1, is utilized in this study. The Lower Hudson River is selected …

Vibration-Induced Densification Of Granule Materials, Ninghua Zhang

Dissertations

Physical experiments as well as discrete element simulations of vibration are carried out. The use of different amplitudes and frequencies are applied in the experiments to facilitate the observation of densification trends with mono-disperse acrylic spheres and multi-disperse polyethylene pellets. For mono-disperse acrylic spheres, four densification trends are found at different vibration conditions, and attaining the "maximum density" is closely related to the combination of vibration frequency and amplitude, in agreement with experiments in the literature. For multi-disperse polyethylene pellets, there is a substantial increase in solids fraction due to the effects of particle shape and surface friction. Computer simulations …

Multi-Spectral Light Interaction Modeling And Imaging Of Skin Lesions, Sachin Vidyanand Patwardhan

Dissertations

Nevoscope as a diagnostic tool for melanoma was evaluated using a white light source with promising results. Information about the lesion depth and its structure will further improve the sensitivity and specificity of melanoma diagnosis. Wavelength-dependent variable penetration power of monochromatic light in the trans-illumination imaging using the Nevoscope can be used to obtain this information. Optimal selection of wavelengths for multi-spectral imaging requires light-tissue interaction modeling. For this, three-dimensional wavelength dependent voxel-based models of skin lesions with different depths are proposed. A Monte Carlo simulation algorithm (MCSVL) is developed in MATLAB and the tissue models are simulated using the …

Ip-Based Virtual Private Networks And Proportional Quality Of Service Differentiation, Jingdi Zeng

Dissertations

IP-based virtual private networks (VPNs) have the potential of delivering cost-effective, secure, and private network-like services. Having surveyed current enabling techniques, an overall picture of IP VPN implementations is presented.

In order to provision the equivalent quality of service (QoS) of legacy connection-oriented layer 2 VPNs (e.g., Frame Relay and ATM), IP VPNs have to overcome the intrinsically best effort characteristics of the Internet. Subsequently, a hierarchical QoS guarantee framework for IP VPNs is proposed, stitching together development progresses from recent research and engineering work.

To differentiate IP VPN QoS, the proportional QoS differentiation model, whose QoS specification granularity compromises …

High Resolution Solar Observations In The Context Of Space Weather Prediction, Guo Yang

Dissertations

Space weather has a great impact on the Earth and human life. It is important to study and monitor active regions on the solar surface and ultimately to predict space weather based on the Sun's activity. In this study, a system that uses the full power of speckle masking imaging by parallel processing to obtain high-spatial resolution images of the solar surface in near real-time has been developed and built. The application of this system greatly improves the ability to monitor the evolution of solar active regions and to predict the adverse effects of space weather. The data obtained by …

Dielectrophoretic Manipulation Of Biological And Non-Biological Analytes In A Microfluidic Channel, Dawn J. Bennett

Dissertations

Micro-total-analytical systems (μTASs) for analyzing chemical/biological substances are now used across a wide variety of applications ranging from biological warfare agent detection to the healthcare industry. The first step in the operation of a μTAS consists of concentrating and separating the analytes of interest from the background matrix and positioning them into selected locations for subsequent analysis. The use of ac electric fields was demonstrated to have promising potential for a μTAS because the application of an ac field suppresses undesirable electrolytic effects in the liquid. The main purpose of this work is to study micro-scale phenomena in a flowing …

The Impacts Of Delphi Communication Structure On Small And Medium Sized Asynchronous Virtual Teams, Hee-Kyung Cho

Dissertations

The improvement of Internet technology has motivated distributed work groups to collaborate without meeting face to face. Although asynchronous meetings through Web-based group communications systems enable groups dispersed temporarily and geographically to collaborate more flexibly, parallel and non-linear communication among dispersed members also challenge effective and efficient group coordination. Moreover, the Web-based asynchronous meeting is distinguished not only from the face-to-face meeting but also from the synchronous computer-supported meeting in terms of coordination process. However, previous asynchronous group communications or virtual team research focused more on the comparison of this new type of meeting with the face-to-face meeting. Not many …

A Conceptual Framework For Using Feedback Control Within Adaptive Traffic Control Systems, Renu Chhonkar

Dissertations

Existing adaptive traffic control strategies lack an effective evaluation procedure to check the performance of the control plan after implementation. In the absence of an effective evaluation procedure, errors introduced in the system such as inaccurate estimates of arrival flows, are carried forward in time and reduce the efficiency of the traffic flow algorithms as they assess prevalent traffic conditions. It is evident that the feed-forward nature of these systems cannot accurately update the estimated quantities, especially during oversaturated conditions.

This research is an attempt to develop a conceptual framework for the application of feedback control within the basic operation …

Development Of Supercritical Processes For Particle Coating / Encapsulation With Polymers, Yulu Wang

Dissertations

This work presents the investigation of particle coating using supercritical fluid processes as novel coating approaches to coat particles from 20 nanometers to 500 microns with different polymers. Particle coating using different supercritical technologies of a modified rapid expansion of a supercritical solution (RESS) for particle coating and a supereritical antisolvent (SAS) process was described.

In the modified RESS process for particle coating, experiments were performed using a pilot-scale supercritical apparatus, glass beads as host particles and two different polymers as coating materials. By adjusting temperature and pressure, the polymer nucleated and precipitated onto the surface of the host particles …

Statistical Study Of Solar Radio Bursts, Gelu-Marius Nita

Dissertations

The peak flux distribution of 40 years of solar radio burst data recorded by NOAA, as a function of frequency and time over a wide range of frequencies, was investigated to quantify the potential impact of radio bursts on wireless systems. Tables of fit parameters, which can be used to find burst occurrence rates in a number of frequency ranges, are presented. The typical power-law index of number density distribution, -1.8, is similar to that found in many hard X-ray studies. Significant changes were found in power-law index with frequency. The results may be useful for designers of current and …

Personality Measurement In The Prediction Of Positive And Negative Police Officer Performance, Brian P. Enright

Dissertations

Police officer selection research has revealed a number of relationships between scores on psychological tests and performance on the job. Although a few of these predictor scales have been consistently linked with job performance, many still require further investigation. It was proposed that the personality scales most consistently linked to job performance concern two broad constructs including: (1) prosocial personality characteristics, and (2) level of psychological distress. Guided by findings from the police outcomes literature and research regarding the factor structure and intercorrelation of MMPI and CPI scales, it was proposed that Scales 4 and 9 from the MMPI and …

Perceptions Of Board Effectiveness In Selected Institutions Of Higher Education In Zimbabwe, Bonginkosi Zvandasara

Dissertations

Problem

The purpose of this study was to identify the level of board effectiveness in selected private and public universities in Zimbabwe as perceived by board members. Also, the study sought to determine the influence of such demographic variables as age, education level, and years of service on the seven factors of university functioning: institutional mission, institutional planning, physical plant, financial management, board membership, board organization and performance, and board/vice chancellor relations.

Method

The survey method was used to collect data. Respondents were asked to complete a 47-item questionnaire and indicate their level of agreement on each of the questions …

Self-Reported Personal Problems Of Adventist Academy Students, Ellen Marsh Crosby

Dissertations

Problem. Adolescence is a time fraught with many challenges. There are no current studies prior to this one for Adventist academy students concerning the whole range of their personal problems.

Method. A survey of students in 14 Adventist academies was conducted in the regular classroom setting using the Personal Problems Checklist for Adolescents (PPC-A). The data were analyzed using descriptive and inferential statistics. Data were tested with one-way, two-way, and, three-way ANOVA and correlation coefficients to determine differences between males and females, age groups 13/14 to 18/19, and in three different settings of day, boarding, and self-supporting Adventist …

An Examination Of Cross-Cultural Understanding In A Global Automotive Company, A. Dale Phillips

Dissertations

Purpose of the Study

Global Motors o f the United States and Baumgart AG of Germany came together to produce an automobile that was marketable in both countries. Since this project involved people from two cultures, the purpose of this study was to examine perceived cultural markers at work during this joint vehicle development project by identifying these markers and investigating their effects on the overall success of the joint-venture project.

Methodology

I chose to use a qualitative methodology, specifically focus groups. All engineers who worked on the project team received an email inviting them to participate and assuring them …

Attitudes Of Junior High Teachers Towards Teaching Students With Learning Disabilities In Inclusive Classes In Public Schools In New Providence, Bahamas, Virginia Alicia Romer

Dissertations

Problem. The implementation of inclusive programs has met disapproval and concerns from many general educators regarding the presence of students with learning disabilities in their classes. The purpose therefore of this study was to survey junior high teachers in New Providence, Bahamas, to determine their attitudes toward teaching students with learning disabilities in general education classes; to investigate the type of instructional methodology used in general classes and to determine if instructional delivery is modified to assist students with learning disabilities; examine whether general educators collaborate with special educators when planning their instruction; and to identify if there are differences …

Validating The Substance Abuse Subtle Screening Inventory For Identifying Substance Abuse Among Adolescents In A Residential Treatment Center, Ann Carol Singler

Dissertations

Purpose. This study examines the construct validity of the Substance Abuse Subtle Screening Inventory for Adolescents (SASSI-A) as a substance-abuse screening instrument for dual-diagnosed adolescents in a residential treatment center.

Method. Using archival records of 336 subjects from a long-term residential treatment center, this study applied a two-group comparison method to examine the construct validity of the SASSI-A for screening substance abuse among adolescents in a residential treatment center. Residents were initially clinically assessed by a state certified counselor as either substance abuser/chemically dependent or non-substance abuser/chemically dependent. At this residential treatment center, the clinical assessment included a full review …

Teacher Perceptions Of Internet-Based Distance Education In Adventist Colleges And Universities : A Mixed-Methods Study, Susan B. Smith

Dissertations

Problem. An examination of Internet-based distance education (IBDE) is important in order to maintain the delivery of quality higher education and to encourage the systemic adoption of policies and practices that promote excellence in IBDE. The quality of online distance education will increasingly become the standard by which students choose a program as their educational options have multiplied with the dramatic growth in distance education.

Method. This was a sequential exploratory mixed-methods study o f the perceptions of teachers on IBDE. It was conducted collaboratively with Pamela Cress who examined administrator perceptions. Data were collected for both studies from teachers …

A Dictionary Of Middle Egyptian For Students Of Biblical Archaeology And Old Testament Studies, Robert D. Bates

Dissertations

Problem. Middle Egyptian has played an increasingly important role in Biblical Archaeology and Old Testament studies. Much of biblical chronology is closely connected to Egyptian chronology; many biblical events record Egyptian involvement, and some of these are included on Egyptian monuments. A knowledge of Middle Egyptian has been crucial in understanding the historical background and cultural context of the biblical world because this phase of the Egyptian language influenced the widest range of Egyptian writing, particularly as it pertains to Old Testament history. Unfortunately, students do not have all the necessary tools for searching for unfamiliar words in Middle Egyptian. …

The Creation And Development Of An Afrocentric Christian College: Imani Kuumba College And Graduate School, Juanita M. Browne Edd

Dissertations

The study examines Imani Kuumba College, (IKC), an Afrocentric Christian College. Since previous research does not examine any higher institution that provides a type of learning that focuses totally on the study of the Afrocentric world, this historical case study describes a unique educational institution that proposes to teach from a focus designed to raise self-esteem for African-Americans and racial understanding for other groups by studying the African-American experience, historically, spiritually and culturally. The study begins with an introduction that outlines the environmental and societal issues that motivated the creation of this innovative institution and its unique program. After discussion …

Leaders' Influence On School Reculturing: A Case Study Of An International School, Brian C. Matthews Edd

Dissertations

Organizational theorists and even practitioners are beginning to use the construct of organizational culture to analyze and characterize the complexities and challenges of organizational life. The construct has been used to metaphorize, frame, interpret, and understand various aspects of organizational life, including leadership and the change process. The literature indicates that leaders can influence an organization by attending to its cultural dimensions. Much of this literature, however, is theoretical and speculative, and the empirical work has focused, for the most part, on business. The overarching purpose of this qualitative study was to enrich understanding of the culture construct and its …

Nursing Students' Experiences In Personal Spiritual Formation And In Provision Of Spiritual Care To Patients, Beverly Jane Cobb

Dissertations

Problem. Nursing professionals acknowledge that (a) spiritual care is part of holistic care, and (b) nursing education about spiritual care of patients is inadequate. Evidence points to the importance of personal faith and spirituality in order for the nurse to more effectively render spiritual care to patients. Enhancing knowledge about how nursing students learn spiritual care can benefit nursing education and, ultimately, patient care. This study explored how students with high faith maturity provided spiritual nursing care to patients.

Method. This study engaged phenomenological methods with a study population selected from two faith-based educational institutions. A total of 187 nursing …

Administrator Perceptions Of Internet-Based Distance Education In Adventist Colleges And Universities : A Mixed-Method Study, Pamela K. Cress

Dissertations

Problem . The quality of Internet-based distance education (IBDE) will increasingly become the standard by which students choose a program as higher educational options multiply due to the dramatic growth in distance education. A system-wide examination of perceptions of IBDE in Adventist highereducation is important to administrators for future institutional strategic planning purposes, systemic adoption of policies and practices that promote excellence, and identifying collaborative efforts.

Method . This was a sequential exploratory mixed-method study of the perceptions of administrators on IBDE. It was conducted collaboratively with Susan Smith who examined teacher perceptions. Data were collected for both studies from …

Job Satisfaction And Organizational Commitment Among Teachers In Norway : A Comparative Study Of Selected Schools From Public And Private Educational Systems, Styrkår A. Dramstad

Dissertations

Problem. Recruiting teachers and motivating them to stay in their jobs represents a major educational challenge in Norway. Growing demands and greater expectations on teachers are factors that have resulted in higher turnover and problems of filling vacancies.

Based on this background, the primary purpose of this study was to determine if job satisfaction is associated with organizational commitment among public and Seventh-day Adventist (SDA) teachers in Norway. The secondary purpose was to compare job satisfaction and organizational commitment between public and SDA teachers in Norway, and to establish linear combination based on the factors of job satisfaction that …

The Improv Church : A Qualitative, Theoretical, And Interdisciplinary Explanation Of Its Appeal To Collegians, Karl Haffner

Dissertations

The college years often represent the time when young people drop out of church. The reasons vary. One of the factors in a decision to abandon church is that college students feel many traditional churches are irrelevant. Conventional methods of pedagogy and communication are typically used. The result is a learning environment that feels stale to many young people.

Some educators are experimenting with new methods of instruction based on advances in learning theories, instructional strategies, and in whole-person learning. The purpose of this study was to consider the Improv Church as a learning environment where these advances in education …

Faculty Perceptions Of Institutional Commitment To The Scholarship Of Engagement, Mackenzi Anne Huyser

Dissertations

Problem. Institutions of higher education are in an important position in relation to fulfillment of their institutional mission. Boyer (1996) introduced to the higher education community an alternative approach to scholarship to address this shift from original mission. While Boyer (1990) examined institutions of higher education as a whole, the distinctive worldview, mission, and philosophy of reformed Christian institutions have not been examined to determine to what extent they are fulfilling their calling to transform creation and redeem culture. Therefore, the purpose of this study was to examine social perceptions that full-time faculty, serving in reformed institutions, hold about their …

How Instructional Leadership Is Addressed In Educational Administration/Leadership Programs, Lolethia Jones Kibble

Dissertations

Problem

Instructional leadership is a major factor in school effectiveness and student achievement, yet it is not widely practiced by school principals. One of the contributing factors, identified in the literature, is a lack of skills and knowledge. Although there is a great deal of information about principal preparation programs, there is very little information on the preparation of school leaders in the practice of instructional leadership behaviors. The purpose of this study was to examine how instructional leadership is addressed in both traditional and restructured educational administration/leadership programs and to what extent this is related to institutional and demographic …

A Comparison Of Kinetic Family Drawings Of Firstborn And Second-Born Siblings, Lynn Anderson

Dissertations

Problem. While the Kinetic Family Drawing (KFD) is a popular assessment tool for clinicians, research on developmental issues and how siblings draw their families is lacking. The purpose of this study was to (a) describe the way siblings perceive themselves and their family interpersonal relationships as expressed in the KFD; and (b) to describe possible developmental age differences in the KFD.

Method. The KFD and a Family Dynamics Interview Schedule were administered to 50 pairs of first- and second-born children from Southwestern Michigan, ages 5-14. The data were analyzed quantitatively by the Wilcoxon Sign Test and Chi-Square, using …