Digital Commons Network^™

Testing Procedures For Group Sequential Clinical Trials With Multiple Survival Endpoints, Rebecca C. Scherzer

Dissertations

This research gives methods for sequential monitoring of survival data in clinical trials with multiple endpoints. We illustrate the use of marginal proportional hazards models and other survival models with various group sequential methods to test multiple survival endpoints at K interim analyses. To adjust for multiplicity at each interim analysis, we consider and extend methods developed by Tang and Geller (1999), Follmann, et al. (1994), and others. These methods are motivated, compared, and evaluated using survival data from a clinical study and using simulation studies.

A Study On Perceptions Of Civil Engineers Regarding Mandatory Continuing Education, Alee A. Sleymann

Dissertations

This study explored the perceptions of civil engineers regarding continuing professional competency requirements for license renewal. In this study,continuing professional competency is assumed to have a direct relationship to public welfare and safety. The policy of mandatory continuing education was adopted primarily for this reason. Currently, mandatory continuing education is adopted by 29 states as the method of assuring continued professional competency.

Many professionals, however, have not welcomed this mandatory continuing education (MCE) policy. The reason for this opposition is the claimed ineffectiveness of this policy in fostering continued competency. In addition, the regulatory boards and policy advocates have not …

Study Of Decarbonization Reaction Of Sodium Carbonate By Sodium Borates, Zaki Yusuf

Dissertations

Today, the chemical process industries are facing many challenges in the wake of skyrocketing energy price. Paper industry as a whole is also not only looking into improving the process efficiency of its chemical recovery process but also is exploring to meet these challenges with gasification based energy/chemical recovery process. Borate based autocausticizing technology appears promising, provided it could be effectively integrated into both types of chemical recovery processes based on the principles of chemistry and chemical engineering.

My research was focused on the decarbonization reactions of sodium carbonate by sodium metaborate (NaBO₂) and sodium diborate (Na_{4 …}

An Examination Of The Job Satisfaction Of Mid-Level Managers In Student Affairs Administration, Jessie L. Grant

Dissertations

This study examined the job satisfaction, dissatisfaction, and attrition (intent to leave their position within the next twelve months) of mid-level managers in student affairs administration using Herzberg's (1966) Motivation-Hygiene Theory.

A purposive sample of 1943 mid-level managers from the American College Personnel Association (ACPA) was sent an invitation to take a Web-based survey. Four hundred seventy seven responses were received. Statistics were calculated for the demographic variables of age, education, gender, ethnic background, degree level and currently pursuing a degree, functional area(s) of the mid-level manager, supervision, Carnegie classification, student enrollment, institutional type, and career tenure in the student …

Changes In Functional Status Of Home Health Cardiac Patients From Admission To Discharge, Mary Rita Mcgoldrick Phd, Mph, Msn, Rn, Anp-Bc

Dissertations

The purpose of this research is to examine the functional status (ADLs and IADLs) in patients with a primary/secondary diagnosis of cardiac disease in the home health setting. The independent variables of dyspnea and service were examined for the effect on discharge functional status while controlling for the effects of age, gender, race, admission functional status, primary and secondary diagnosis. A descriptive correlational, non-experimental study of cardiac patients in an urban home health agency from January 2003 to December 2004 was conducted using data collected through a retrospective chart review. Seventeen areas of OASIS (ADL and IADL) were assessed for …

So You Think It's Inclusion…Think Again: A Quantitative Analysis Of Stakeholder Perceptions In Community Youth Organizations, Mary Mcallister Shea Edd

Dissertations

Over the last thirty years, a cultural transformation has occurred in public schools as students with disabilities have slowly moved from segregated sites and special day classes to more inclusive classroom environments. Although this change has largely been driven by legislative mandate, including the requirement that students be supported in the least restrictive environment possible, the benefits of inclusion have been exceedingly well documented in the literature. Unfortunately, the inclusiveness seen within schools has not extended to the provision of out-of-school programs, and as a result, sixteen years after the passage of the Americans with Disabilities Act, children with disabilities …

Nilpotent Orbits On Infinitesimal Symmetric Spaces, Joseph A. Fox

Dissertations

Let G be a reductive linear algebraic group defined over an algebraically closed field k whose characteristic is good for G. Let [straight theta] be an involution defined on G, and let K be the subgroup of G consisting of elements fixed by [straight theta]. The differential of [straight theta], also denoted [straight theta], is an involution of the Lie algebra [Special characters omitted.] = Lie (G ), and it decomposes [Special characters omitted.] into +1- and -1-eigenspaces, [Special characters omitted.] and [Special characters omitted.] , respectively. The space [Special characters omitted.] identifies with the tangent space at the …

Comparative Genomic Analyses And Expression Of A Set Of Overlapping Open Reading Frames Of Frog Virus 3, Type Species Of Ranavirus (Family Iridoviridae), Wendy Guat Hoon Tan

Dissertations

Frog virus 3 (FV3) is the type species member of the genus Ranavirus (family Iridoviridae ). To better understand the molecular mechanisms involved in the replication of FV3, including transcription of its highly methylated DNA genome, the complete nucleotide sequence of the FV3 genome has been determined. The FV3 genome is 105, 903 base pairs long excluding the terminal redundancy. The G+C content of FV3 genome is 55% and it encodes 98 non-overlappingpotential open reading frames (ORFs) containing 50 to 1293 amino acids. Eighty-four ORFs have significant homology to known proteins of other iridoviruses, whereas 14 are unique FV3 ORFs. …

Clients' Expectations Of Public Health Nurses' Home Visits, Eva G. Miller Dnsc, Ms, Rn, Phn

Dissertations

Although there is considerable research on the relationship between client expectations and outcomes of care in acute care settings, less is known about clients' expectations for public health nurses' home visits. The aim of this study was to understand clients' expectations of public health nurses' home visits as a first step in making explicit how expectations affect client responses to, and ultimately, outcomes of public health nurses' care. Interviews were conducted with a convenience sample of 19 primary caretakers of high-risk infants admitted to a Neonatal Intensive Care Unit (NICU) and voluntarily enrolled in a High-Risk Infant (HRI) Program in …

Homeless Mothers' Perceptions Of Parenting In Shelters, Sarah E. Young Whitaker Dnsc, Msn, Rn

Dissertations

Descriptions of parenting in a homeless shelter were obtained from nine single mothers housed in one of two shelters in a major southwestern border metroplex. Case study methodology was used to obtain their perspectives on parenting in this unique context. Content analysis was used to organize and analyze emerging themes. Major themes that emerged from the study were (a) a lack of autonomy, (b) gaining access to material resources, (c) lack of privacy, (d) constant change and insecurity in the environment, (e) differing values, and (e) psychosocial support.

Male Arab-Muslims Health And Health Promotion Perceptions And Practices, Abdel-Raheem O. Yosef Phd, Msn, Rn

Dissertations

The Arab Muslim population is one of the dramatically increasing minorities in the United States. In addition to other factors, gender, religion and cultural background influence individuals' beliefs, behaviors, and attitudes to health and illness. Little is known about Arab American male immigrants, how they perceive illness, how they promote their health, and the stressors they experience and barriers they face in accessing the American health care system. The purpose of this study was to develop knowledge about the male Arab-Muslims' health perceptions and health promotion perceptions and practices. This qualitative exploratory study used a grounded theory approach to gain …

Terrorism And College Students: A Generation's Response To September 11, 2001, Robert Mason Wild

Dissertations

The terrorist attacks on the United States of September 11, 2001 marked a significant cultural turning point for Americans. The tragic destruction of the World Trade Towers , the damage to the Pentagon and the loss of thousands of civilian lives brought an end to the optimism and feelings of security and invulnerability that marked the decade of the 1990s. Students who were enrolled in college at the time of the attacks were affected as well. This qualitative study examines the emotions and attitudes of 50 students enrolled a mid-sized, private research institution on September 11, 2001. The study explores …

Text Mining With Exploitation Of User's Background Knowledge : Discovering Novel Association Rules From Text, Xin Chen

Dissertations

The goal of text mining is to find interesting and non-trivial patterns or knowledge from unstructured documents. Both objective and subjective measures have been proposed in the literature to evaluate the interestingness of discovered patterns. However, objective measures alone are insufficient because such measures do not consider knowledge and interests of the users. Subjective measures require explicit input of user expectations which is difficult or even impossible to obtain in text mining environments.

This study proposes a user-oriented text-mining framework and applies it to the problem of discovering novel association rules from documents. The developed system, uMining, consists of two …

Facial Feature Representation And Recognition, Chao-Fa Chuang

Dissertations

Facial expression provides an important behavioral measure for studies of emotion, cognitive processes, and social interaction. Facial expression representation and recognition have become a promising research area during recent years. Its applications include human-computer interfaces, human emotion analysis, and medical care and cure.

In this dissertation, the fundamental techniques will be first reviewed, and the developments of the novel algorithms and theorems will be presented later. The objective of the proposed algorithm is to provide a reliable, fast, and integrated procedure to recognize either seven prototypical, emotion-specified expressions (e.g., happy, neutral, angry, disgust, fear, sad, and surprise in JAFFE database) …

Design And Stability Analysis Of High Performance Packet Switches, Zhen Guo

Dissertations

With the rapid development of optical interconnection technology, high-performance packet switches are required to resolve contentions in a fast manner to satisfy the demand for high throughput and high speed rates. Combined input-crosspoint buffered (CICB) switches are an alternative to input-buffered (IB) packet switches to provide high-performance switching and to relax arbitration timing for packet switches with high-speed ports.

A maximum weight matching (MWM) scheme can provide 100% throughput under admissible traffic for lB switches. However, the high complexity of MWM prohibits its implementation in high-speed switches. In this dissertation, a feedback-based arbitration scheme for CICB switches is studied, where …

Probabilistic Approaches To The Design Of Wireless Ad Hoc And Sensor Networks, Zhen Guo

Dissertations

The emerging wireless technologies has made ubiquitous wireless access a reality and enabled wireless systems to support a large variety of applications. Since the wireless self-configuring networks do not require infrastructure and promise greater flexibility and better coverage, wireless ad hoc and sensor networks have been under intensive research. It is believed that wireless ad hoc and sensor networks can become as important as the Internet. Just as the Internet allows access to digital information anywhere, ad hoc and sensor networks will provide remote interaction with the physical world.

Dynamics of the object distribution is one of the most important …

Color Image Quality Measures And Retrieval, Yan-Yu Fu

Dissertations

The focus of this dissertation is mainly on color image, especially on the images with lossy compression. Issues related to color quantization, color correction, color image retrieval and color image quality evaluation are addressed. A no-reference color image quality index is proposed. A novel color correction method applied to low bit-rate JPEG image is developed. A novel method for content-based image retrieval based upon combined feature vectors of shape, texture, and color similarities has been suggested. In addition, an image specific color reduction method has been introduced, which allows a 24-bit JPEG image to be shown in the 8-bit color …

Dynamic Simulations Of Particle Suspensions Subjected To An External Electric-Field, Xianjin Jiang

Dissertations

A numerical method is performed to study the suspension of polarizable particles in nonconductive solvents subjected to external electric fields. Such particles experience both hydrodynamic and electrostatic interactions. The hydrodynamic force acting on the particles is determined using the Stokesian dynamics method under the assumption that the Reynolds number is much smaller than 1, while the electrostatic force is determined by differentiating the electrostatic energy of the suspension, which is computed from the induced particle dipoles. In addition, the multiple image method is used to compensate for the electrostatic force when two particles are close to each other. Because the …

Multilevel Adaptive Security System, Hongwei Li

Dissertations

Recent trends show increased demand for content-rich media such as images, videos and text in ad-hoc communication. Since such content often tends to be private, sensitive, or paid for, there exists a requirement for securing such information over resource constrained ad hoc networks. In this work, traditional data security mechanisms, existing ad hoc secure routing protocols and multilevel security are first reviewed. Then a new system, called the Multilevel Adaptive Security System, which incorporates the multilevel security concept at both the application layer and the network layer, is proposed to provide adaptive security services for data and routing processes.

MLASS …

Modeling, Design, And Fabrication Of Pulsed Fluidic Micro-Actuators, Max Roman

Dissertations

The forced vibration of a thin flexible plate or membrane in a sealed cavity with a small opening can cause fluid to be pumped into and out-of the cavity. At particular frequencies and amplitudes of vibration, a streaming of vortex rings can occur near the orifice. These vortex rings move under their own self-induced momentum. Downstream of the opening the rings ultimately break up and can form a fully developed jet. This work is dedicated to the analysis, design, and fabrication of electrostatic micro fluidic actuators, which use the pulsing mechanism described above to generate a fluid flow. Particle Image …

Ligand-Based Design Of Dopamine Reuptake Inhibitors : Fuzzy Relational Clustering And 2-D And 3-D Qsar Modleing, Milind Misra

Dissertations

As the three-dimensional structure of the dopamine transporter (DAT) remains undiscovered, any attempt to model the binding of drug-like ligands to this protein must necessarily include strategies that use ligand information. For flexible ligands that bind to the DAT, the identification of the binding conformation becomes an important but challenging task. In the first part of this work, the selection of a few representative structures as putative binding conformations from a large collection of conformations of a flexible GBR 12909 analogue was demonstrated by cluster analysis. Novel structurebased features that can be easily generalized to other molecules were developed and …

The Effects Of Aging On Cardiac Mechanics, Samuel C. Lieber

Dissertations

It is well established that the aging heart exhibits left ventricular (LV) diastolic dysfunction and changes in mechanical properties, which have been attributed to alterations in the extracellular matrix (ECM). The investigators tested the hypothesis that the mechanical properties of cardiac myocytes significantly change with aging thereby contributing to the LV diastolic dysfunction. Cellular mechanical properties were determined by indenting cells with an atomic force microscope (AFM). The indentation results were interpreted by modeling the AFM probe as a blunted cone and determining an apparent elastic modulus (B) with classical infinitesimal strain theory (CIST). A commercially available finite element software …

Mobile Ad Hoc Networks For Intelligent Systems, Zhigang Wang

Dissertations

Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. Mobile ad hoc networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. They do not rely on specialized routers for path discovery and traffic routing. Research on ad hoc networks has been extensively investigated in the past few years and related work has focused on many of the layers of the communications architecture.

This research intends to investigate applications of MANET for intelligent systems, including intelligent transportation system (ITS), sensor …

Design And Resource Management Of Reconfigurable Multiprocessors For Data-Parallel Applications, Xiaofang Wang

Dissertations

FPGA (Field-Programmable Gate Array)-based custom reconfigurable computing machines have established themselves as low-cost and low-risk alternatives to ASIC (Application-Specific Integrated Circuit) implementations and general-purpose microprocessors in accelerating a wide range of computation-intensive applications. Most often they are Application Specific Programmable Circuiits (ASPCs), which are developer programmable instead of user programmable. The major disadvantages of ASPCs are minimal programmability, and significant time and energy overheads caused by required hardware reconfiguration when the problem size outnumbers the available reconfigurable resources; these problems are expected to become more serious with increases in the FPGA chip size. On the other hand, dominant high-performance computing …

Dynamic Measuring Tools For Online Discourse, Jeffrey S. Saltz

Dissertations

When evaluating participation within an Asynchronous Learning Network (ALN), current best practices include counting messages and reviewing participant surveys. To understand the impact of more advanced dynamic measurement tools for use within an ALN, a web-based tool, known as iPET (the integrated Participation Evaluation Tool), was created. iPET, which leverages Social Network Analysis and Information Visualization techniques, was then evaluated via an empirical study. This research demonstrates that using a tool such as iPET increases participation within an ALN without increasing facilitator workload. Due to the fact that active online discussion is a key factor in the success of an …

Study Of Organic Reactions In Pyridinium-Based Ionic Liquids, Ying Xiao

Dissertations

Recently, ionic liquids have attracted a lot of attention as novel materials for organic transformations. This is due to their unique properties, which make them suitable substitutes for organic solvents. Most of the available literature is focused on the application of imidazolium-based ionic liquids for organic reactions, while very limited information is available on the application of pyridinium-based ionic liquids.

In this study, two different ionic liquids, 1 -ethyl-pyridinium tetrafluoroborate ([EtPy]⁺[BF₄]^-) and 1 -ethyl-pyridinium trifluoroacetate ([EtPy]⁺[CF₃COO]^-) have been investigated. Compared to previous reports, the synthetic technique for preparation …

Flow-Oriented Anomaly-Based Detection Of Denial Of Service Attacks With Flow-Control-Assisted Mitigation, Sui Song

Dissertations

Flooding-based distributed denial-of-service (DDoS) attacks present a serious and major threat to the targeted enterprises and hosts. Current protection technologies are still largely inadequate in mitigating such attacks, especially if they are large-scale. In this doctoral dissertation, the Computer Network Management and Control System (CNMCS) is proposed and investigated; it consists of the Flow-based Network Intrusion Detection System (FNIDS), the Flow-based Congestion Control (FCC) System, and the Server Bandwidth Management System (SBMS). These components form a composite defense system intended to protect against DDoS flooding attacks. The system as a whole adopts a flow-oriented and anomaly-based approach to the detection …

Network Level Performance Of Differentiated Services (Diffserv) Networks, Li Zhu

Dissertations

The Differentiated Services (DiffServ) architecture is a promising means of providing Quality of Service (QoS) in Internet. In DiffServ networks, three service classes, or Per-hop Behaviors (PHBs), have been defined: Expedited Forwarding (EF), Assured Forwarding (AF) and Best Effort (BE).

In this dissertation, the performance of DiffServ networks at the network level, such as end-to-end QoS, network stability, and fairness of bandwidth allocation over the entire network have been extensively investigated.

It has been shown in literature that the end-to-end delay of EF traffic can go to infinity even in an over-provisioned network. In this dissertation, a simple scalable aggregate …

Phase Transitions Of Poly (L-Lactic Acid) In Bulk And In Solution, Jing Zhang

Dissertations

Poly(L-lactic acid) (PLLA) has been subject to intensive research in recent years because of its biodegradability. Applications of PLLA, such as porous tissue engineering scaffolds and excipients for controlled release, have been developed in the biomedical and pharmaceutical fields. The crystal structures and morphologies of this semicrystalline polyester are the underlying factors that determine the mechanical and degradation properties of PLLA.

A fundamental understanding of the development of crystal structures and morphologies during the phase transitions of PLLA in bulk and in solution is pursued in this dissertation. Synchrotron wide- and small-angle x-ray scattering (WAXS and SAXS) are adopted as …

Development Of Environmentally Benign Microencapsulation With Polymer Microspheres And Liposomes, Baohua Yue

Dissertations

Microencapsulation means applying a shell-like coating to encapsulate the contents of interest in a particle form with a size range of few micrometers or below. In this work, aqueous liposome systems and polymer based encapsulation of fine particles in supercritical CO₂ were studied. Compared to many other microencapsulation methods, these two methodologies feature reduction/prevention of using organic solvents, making them particularly attractive as green technology.

For polymer microencapsulation, a novel in situ polymerization based process to encapsulate various types of fine particles, include drugs, fire retardant, inorganic nanoparticles, and carbon nanotubes, was developed. In the process, host particles, monomers …