Digital Commons Network^™

Numerical Analysis And Computational Topology For Scientific Visualization, Hugh Cassidy

Doctoral Dissertations

In Computer Aided Geometric Design (CAGD) B-splines are frequently used to model complex geometric objects. The spline models are smooth structures but piecewise linear (PL) approximations are typically used to render the spline. Aeronautical, automotive and chemical simulations rely on topological algorithms to provide mathematically correct visualization. Topological changes are of significant interest to domain scientists, where self-intersection is a critical event that is often difficult to detect. This research focuses on algorithms that guarantee topology, in terms of ambient isotopic equivalence, between a spline curve and its PL approximations, as used in both static and dynamic visualization. Sufficient conditions …

Effects Of Two Six-Week Exercise Prescriptions On Running Performance And Clinical Manifestations Of Cardiometabolic Disease, Evan C. Johnson

Doctoral Dissertations

Adequate exercise is a powerful stimulus for change in fitness and a preventive and therapeutic stimulus for lifestyle related diseases. However, optimal dosage methodologies for exercise prescription remain unclear. Objective: To determine differences in achieved exercise intensity and the performance and metabolic disease related outcomes of six weeks of run training prescribed either via heart rate (HR) or rating of perceived exertion (RPE). Design: Laboratory and field controlled trial. Participants were assigned into a heart rate training group (HRTG) and a RPE training group (RPETG) in a non-randomized, counter-balanced method controlling for baseline values. Methods: Forty males completed maximal graded …

Nurses' Decision Making And Pain Management Outcomes, John Fedo

Doctoral Dissertations

Nurses’ Decision-making Processes and Pain Management Outcomes

John M. Fedo, PhD.

University of Connecticut, 2014

Abstract

The purpose of this study was to identify the cognitive processes used by nurses when making pain management decisions by testing how the structure of a task (well-structured or ill-structured) affects use of analytic cognitive processes. Identifying cognitive processes which nurses use to make clinical decisions in the practice setting may be used to gain understanding of which types of cognitive processes are more effective when managing decisions for planned pain management interventions. Two hypotheses were tested. H1: Nurses reading the well-structured patient vignette …

Multi-Objective Approaches In Transit Stop Location Problem, Sha Mamun

Doctoral Dissertations

An efficient bus network design is a difficult problem, and hence is usually considered as a series of sub-problems solved sequentially. The bus stop location problem (BSLP) is foremost in this series of problems. The BSLP in this research is formulated as a mixed integer problem (MIP) that consideres three important design sub-problems: stop location, demand allocation and service frequency. Given a set of candidate bus stops, the level of trip connectivity and origindestination pair-wise trip demands, the problem is to answer the following related questions. How many bus stops should be required and where should they be located? Which …

Vulnerability Analysis Of Cyber-Behavioral Biometric Authentication, Abdul Serwadda

Doctoral Dissertations

Research on cyber-behavioral biometric authentication has traditionally assumed naïve (or zero-effort) impostors who make no attempt to generate sophisticated forgeries of biometric samples. Given the plethora of adversarial technologies on the Internet, it is questionable as to whether the zero-effort threat model provides a realistic estimate of how these authentication systems would perform in the wake of adversity. To better evaluate the efficiency of these authentication systems, there is need for research on algorithmic attacks which simulate the state-of-the-art threats.

To tackle this problem, we took the case of keystroke and touch-based authentication and developed a new family of algorithmic …

An Examination Of The Effectiveness Of The Louisiana Gear Up Program In Promoting Self-Efficacy, Improving Academic Achievement And Increasing Teachers' Aspirations For Their Students, Candi Hill

Doctoral Dissertations

Students are likely to avoid academic pursuits if they lack academic self-efficacy (Bandura, 2000). Furthermore, past poor academic performance contributes to the development of low academic self-efficacy. Students who participate in extracurricular activities, like LA GEAR UP, demonstrate better academic achievement and less risk-taking behaviors than non-participating students (Barber, Stone, & Hunt, 2003). Research supports the notion that LA GEAR UP is an effective way to improve students' academic performance and to reduce the number of disciplinary referrals students receive (Beer, 2009). Additionally, within the academic literature research has demonstrated that teachers' attributions about students are based upon their perceptions …

Foundations Of Coverage Algorithms In Autonomic Mobile Sensor Networks, Mark Edward Snyder

Doctoral Dissertations

"Drones are poised to become a prominent focus of advances in the near future as hardware platforms manufactured via mass production become accessible to consumers in higher quantities at lower costs than ever before. As more ways to utilize such devices become more popular, algorithms for directing the activities of mobile sensors must expand in order to automate their work.

This work explores algorithms used to direct the behavior of networks of autonomous mobile sensors, and in particular how such networks can operate to achieve coverage of a field using mobility. We focus special attention to the way limited mobility …

The Effect Of Physical Activity On Fourth-Grade Students' Reading Achievement In One Elementary School, Donna Lynn Bush

Doctoral Dissertations

There is a critical need to improve students' reading and comprehending ability. In 2011, Louisiana's students scored well below the national average in reading on the National Assessment of Educational Progress (NAEP). Research suggests there is a connection between physical activity and students' ability to focus and comprehend during reading class, therefore improving reading comprehension. However, many school districts are cutting back physical activity time in favor of more academic time.

The purpose of this 12-week study was to examine the effect of physical activity on fourth-grade students' achievement in reading. A quasi-experimental design was used to study 108 fourth-grade …

Performance Modeling And Optimization Techniques For Heterogeneous Computing, Supada Laosooksathit

Doctoral Dissertations

Since Graphics Processing Units (CPUs) have increasingly gained popularity amoung non-graphic and computational applications, known as General-Purpose computation on GPU (GPGPU), CPUs have been deployed in many clusters, including the world's fastest supercomputer. However, to make the most efficiency from a GPU system, one should consider both performance and reliability of the system.

This dissertation makes four major contributions. First, the two-level checkpoint/restart protocol that aims to reduce the checkpoint and recovery costs with a latency hiding strategy in a system between a CPU (Central Processing Unit) and a GPU is proposed. The experimental results and analysis reveals some benefits, …

Dabigatran And Warfarin For Stroke Prevention In Atrial Fibrillation: Use, Switching, And Clinical Effects Following New Market Entry In Real-World Patients, Julie C. Lauffenburger '03

Doctoral Dissertations

Patients with atrial fibrillation frequently benefit from anticoagulation to prevent stroke and systemic embolism. For decades, warfarin was the primary oral anticoagulant option despite its narrow therapeutic index requiring monitoring and drug-drug interactions. Dabigatran’s recent availability provides practical advantages including no monitoring and fewer interactions; however, it lacks a convenient reversal agent for bleeding events. Currently, it is unclear what factors have driven anticoagulant utilization since dabigatran’s introduction, and little real-world evidence on the agents’ comparative effectiveness and safety is available. The objectives were to describe dabigatran and warfarin’s utilization and switching patterns and assess their comparative effectiveness and safety. …

Causes And Consequences Of Diversity Within Experimental Biofilms Of Pseudomonas Aeruginosa, Kenneth Mark Flynn

Doctoral Dissertations

Currently, we do not understand how much biodiversity may be maintained in any environment, especially not in the structured environments of biofilms, which constitute the dominant mode of microbial life. Although maintenance is associated with the complex spatial structure of biofilm architecture and resulting ecological opportunities, how both the abiotic and biotic environment defines available niches remains poorly understood. Here, we experimentally evolved three replicate populations founded by Pseudomonas aeruginosa strain PA14 for 540 generations under conditions favoring a regular cycle of biofilm formation and dispersal. Utilizing a variety of laboratory and genomic sequencing approaches, we characterize the population genetic …

Competencies For The 21st Century: Teaching An Understanding Of Others, Critical Thinking, Leadership And A Sense Of Obligation. Perceptions Of Educational Leaders., Michael F. Schwartz

Doctoral Dissertations

In the 18th century, utilitarian writers highlighted the importance of a sense of obligation, an understanding of others, and the ability to think critically (Daniels, Bizar, & Zemelman, 2001; Kant, 1785/2008). Additionally, scholars stressed the importance of leadership (Burns, 1978). Teacher instruction in the 19th century incorporated many of these values (Kliebard, 2004). However as the common school developed in the early 19th century there was a shift from these values toward a common curriculum meeting industrial needs (Tyack, 1974). As the 20th century ended, significant federal and state legislation further funneled school curriculum to focus on very specific instruction …

Estimating Proximity To The Asymmetric Reconnection X-Line, Matthew Argall

Doctoral Dissertations

Magnetic reconnection is a process that changes magnetic topology, allows plasma transport across boundaries, and converts field potential energy to particle kinetic energy. All of these processes are tied to the X-line, or site of reconnection, yet current methods of locating the reconnection site either do not uniquely identify the the X-line or have not been tested when asymmetries in field strength and plasma density and temperature are present. Furthermore, identification of spacial structures (such as the X-line) as they traverse satellites is limited by hardware constraints. This thesis proposes a new method of locating the reconnection site for asymmetric …

Asymmetry In The Magnocellular And Parvocellular Pathways, Jenny Louise Lang

Doctoral Dissertations

Why humans are less sensitive to increment than decrement contrast remains unknown. One hypothesis is that the psychophysical asymmetry in increment and decrement thresholds results from an asymmetry in respective ON and OFF cell contrast gains. Contrast gain also differs, however, by the visual pathway within which the ON and OFF cells travel. Cells show greater contrast gain in the magnocellular (M) than parvocellular (P) pathway. Therefore, the asymmetry in increment and decrement thresholds may also differ by visual pathway. My first three experiments established that observers were more sensitive to decrement than increment contrast in both pathways, in monocular …

A Generalized Optimal Power Flow Program For Distribution System Analysis And Operation With Distributed Energy Resources And Solid State Transformers, Fanjun Meng

Doctoral Dissertations

"The present distribution system is gradually trending towards a smart grid paradigm with massive development of distributed energy resources (DER), advanced power electronics interfaces, and a digitalized communication platform. Such profound changes bring challenges as well as opportunities for an entity like the distribution network operator (DNO) to optimally operate DERs and other controllable elements to achieve higher levels of energy efficiency, economic benefits, supply reliability and power quality.

The major contribution of this dissertation is in the development of a generalized three-phase optimal power flow (OPF) program in a novel control scheme for future distribution system optimization and economic …

On Some Inferential Problems With Recurrent Event Models, Withanage Ajith Raveendra De Mel

Doctoral Dissertations

"Recurrent events (RE) occur in many disciplines, such as biomedical, engineering, actuarial science, sociology, economy to name a few. It is then important to develop dynamic models for their modeling and analysis. Of interest with data collected in a RE monitoring are inferential problems pertaining to the distribution function F of the time between occurrences, or that of the distribution function G of the monitoring window, and their functionals such as quantiles, mean. These problems include, but not limited to: estimating F parametrically or nonparametrically; goodness of fit tests on an hypothesized family of distributions; efficient of tests; regression-type models, …

Teachers Adapting Common Core Informational-Text Writing Instruction For Students With Mild To Moderate Disabilities, Diana Hawley

Doctoral Dissertations

With the adoption of the Common Core State Standards, students must now become skilled at using different types of writing to help them critique text and process information. They also are required to write informational text. Informational-text writing is challenging for students with mild to moderate disabilities, including students with language-learning disabilities, who often struggle with aspects of language necessary for learning to read and write. These students show striking challenges with productivity, grammatical and spelling accuracy, and sentence complexity, with differences in performance by genre (Koutsoftas & Gray, 2012; Scott & Windsor, 2000; Troia, Lin, Cohen, & Monroe, 2011). …

Speciation Dynamics Of An Agent-Based Evolution Model In Phenotype Space, Adam David Scott

Doctoral Dissertations

"This dissertation is an exploration of phase transition behavior and clustering of populations of organisms in an agent-based model of evolutionary dynamics. The agents in the model are organisms, described as branching-coalescing random walkers, which are characterized by their coordinates in a two-dimensional phenotype space. Neutral evolutionary conditions are assumed, such that no organism has a fitness advantage regardless of its phenotype location. Lineages of organisms evolve by limiting the maximum possible offspring distance from their parent(s) (mutability, which is the only heritable trait) along each coordinate in phenotype space. As mutability is varied, a non-equilibrium phase transition is shown …

Turbo Equalization For Multiple-Input Multiple-Output (Mimo) Wireless Communication Systems, Longbao Wang

Doctoral Dissertations

"This dissertation investigates both of the frequency domain and time domain turbo equalization with multiple-input multiple-output (MIMO) fading channels for radio frequency and underwater acoustic communications. First, a low complexity frequency domain turbo equalization (FDTE) is proposed for the MIMO systems with zero padding (ZP) or cyclic prefix (CP) inserted between the transmitted data blocks and its performance is tested on the real-world UWA communications experiments.

Second, as high speed communication system requires efficient bandwidth usage and power consumption, CP or ZP is not transmitted as auxiliary information. An inter-block interference cancelation and CP reconstruction algorithm is developed to re-arrange …

Thermophysical Properties Of Reaction Processed Zirconium Diboride, Jason Michael Lonergan

Doctoral Dissertations

"This dissertation focuses on the thermophysical properties of high purity zirconium diboride ceramics. These ceramics have shown promise for potential applications such as leading edge materials for next generation hypersonic vehicles. The overall goal of this work was to improve the understanding of the thermal properties and maximize the thermal conductivity of ZrB₂. Four main areas were investigated in this work. First, the sintering kinetics and the intrinsic thermal properties of reaction processed ZrB₂ were studied and compared to ZrB₂ produced by hot pressing commercial powders. The reaction process produced ceramics with higher thermal conductivity and …

Crustal Thickness And Vp/Vs Beneath The Western United States: Constraints From Stacking Of Receiver Functions, Uranbaigal Purevsuren

Doctoral Dissertations

"This study investigates crustal characteristics beneath the western United States. Crustal parameters, including crustal thickness (H), mean Vp/Vs, and the sharpness of the Moho as quantified by the amplitude of the P-to-S converted phases from the Moho, are measured at a total of 1000 permanent and portable broadband seismic stations using over 150,000 receiver functions recorded between 1988 and 2012. The study area is composed of a diverse set of tectonic provinces formed by a series of tectonic events, and is thus ideal for investigating crustal formation and modification by different tectonic processes. The resulting crustal thickness varies from …

Proactive Search: Using Outcome-Based Dynamic Nearest-Neighbor Recommendation Algorithms To Improve Search Engine Efficacy, Christopher Shaun Wagner

Doctoral Dissertations

"The explosion of readily available electronic information has changed the focus of data processing from data generation to data discovery. The prevalent use of search engines has generated extensive research into improving the speed and accuracy of searches. The goal of this research is to accurately predict user behavior as a means to proactively improve speed, accuracy, and predictability of search engines. The proactive approach eliminates query entry time and hence reduces the overall processing time, improving speed. Assuming success, the user locates an electronic resource of interest, improving accuracy.

Algorithms that have been shown to predict many vastly different …

Aerogels As Diverse Nanomaterials, Abhishek N. Bang

Doctoral Dissertations

"Aerogels are 3-D light-weight nanoporous materials pursued for their low thermal conductivity, low dielectric constant and high acoustic attenuation. Those exceptional macroscopic properties of aerogels are dependent on the chemical nature of nanoparticles, complex hierarchical solid skeletal framework and porosity. Also, the free space can become host for functional guests such as pharmaceuticals. In chapter I, we investigated randomly mesoporous bio-compatible polymer-crosslinked dysprosia aerogels as drug delivery vehicles and demonstrated storage and release of drugs under physiological conditions. Comparative study with ordered and randomly mesoporous silica showed high drug uptake and slower release rate for random nanostructures (silica or dysprosia) …

Bay Area Student Involvement In The Environmental And Food Justice Movements: A Narrative Of Motivations, Experiences, And Community Impact, Laura E. Solof

Doctoral Dissertations

Many California public school students lack exposure to any formal, academic curriculum that emphasizes environmental awareness and activism. This may result in a population of adults who believe they know more about the environment than they actually do, lack the skills to compete in an expanding green job market, lack creativity and the ability to problem-solve, suffer from obesity, depression, anxiety, and attention disorders, and unknowingly contribute to the ever-increasing problems of air and water pollution, land and habitat destruction, and other environmental injustices. Community organizations and university programs are filling this much-needed gap in student environmental education, as they …

The Effects Of Explicit Listening Strategy Instruction On The Listening Comprehension Of English As Second Language (Esl) Community College Students, Yi Guan

Doctoral Dissertations

This mixed methods study explored the effects of explicit listening strategy instruction on the beginning-level ESL learner's listening comprehension at a community college in Northern California. Most previous studies measured the effectiveness of listening strategy instruction by comparing students' test scores, but little research explored the students' listening strategy development and their perceptions of the strategy instruction. Furthermore, no prior research exists on the effects of listening strategy instruction among community college students.

The researcher employed the concurrent triangulation approach, collecting and analyzing both quantitative and qualitative data simultaneously. Data sources included interviews, a listening test, background surveys, and classroom …

The Effects Of The Read 180 Program On Oral Reading Fluency, Linguistic Comprehension, And Reading Comprehension With Secondary Special Education Students, David Lyon Teja

Doctoral Dissertations

There is great concern about secondary special education students reading achievement in decoding, listening comprehension, and reading comprehension. The READ 180 Program is an evidence and scientific based reading program that includes direct instruction, computer aided instruction, and reading materials that are high interest and implement the common core. The purpose of this study was to see the differences in oral reading fluency, linguistic comprehension, and reading comprehension in a pretest posttest model over a fourteen-week testing period. Ten ninth grade secondary students who were reading below the 25th percentile were instructed with the READ 180 Program with fidelity (90 …

Four Preservice Teachers' Use Of Mathematical Knowledge During Lesson Planning And Instruction In The Field Experience, Margaret Swearingen

Doctoral Dissertations

The field experience of a teacher education program offers the opportunity for authentic practice in lesson planning and instruction for preservice teachers prior to their transition into their teaching career. However, preservice teachers often struggle applying their developing knowledge and skills because of the multifaceted nature of the field experience context. This complexity is particularly true in mathematics instruction since it includes simultaneously understanding mathematical concepts and mathematical procedure standards during instruction.

This study used mini-case studies to examine how four preservice teachers used their developing mathematical knowledge learned in the teacher education program while lesson planning and teaching within …

Ready To Write: Exploring The Student Perspective On The Transition To College, Julie Sullivan

Doctoral Dissertations

Written communication is a cornerstone of college and career success, yet many students arrive at college underprepared for the writing demands of the academic discourse community. The potential reasons for the perceived gap in writing ability point to the ongoing challenges of education in the United States. As the population pursuing college degrees becomes more diverse, expectations differ between high school and college, equity in education issues persist and standardization focuses on academic skills, overlooking the potential role that nonacademic or "soft" skills play in student success. When decisions are made to address these concerns, the student perspective is frequently …

An Investigation Of Special Education Teachers' Perceptions Of The Effectiveness Of A Systematic 7-Step Virtual Worlds Teacher Training Workshop For Increasing Social Skills, Natalie Christina Nussli

Doctoral Dissertations

This study describes how a systematic 7-Step Virtual Worlds Teacher Training Workshop promoting inquiry, experiential learning, and sociocultural theory guided the enculturation of 18 special education teachers into three-dimensional virtual worlds. The main purpose was to enable these teachers to make informed decisions about the usability of virtual worlds for students with social skills challenges, such as students with autism. Mixed-methods data analysis and triangulation were based on the analysis of seven instruments. Six of the seven steps of the intervention received high ratings indicating its viability for teachers' professional development opportunities

Rehearsal And Enactment For Teaching In Urban School Settings: A Qualitative Study Investigating The Connections Between A Math Methods Course And Fieldwork, Rajeev Virmani

Doctoral Dissertations

In this dissertation, I studied teacher education reform efforts aimed at improving the preparation of preservice teachers through the use of rehearsals in a math methods class. As many experts in the field of teacher education call for curricula in which preservice teachers learn from and in practice, I investigated a type of pedagogy called rehearsals within a practice-based teacher education setting that may afford preservice teachers with the initial preparation needed to become effective teachers.

In this qualitative study, I examined how three preservice teachers and math methods instructors rehearse the high leverage practice of leading a whole-class discussion. …