Digital Commons Network^™

Energy Methods For Reaction-Diffusion Problems, Xing Zhong

Dissertations

Nonlinear reaction-diffusion equations arise in many areas of applied sciences such as combustion modeling, population dynamics, chemical kinetics, etc. A fundamental problem in the studies of these equations is to understand the long time behavior of solutions of the associated Cauchy problem. These kinds of questions were originally studied in the context of combustion modeling.

For suitable nonlinearity and a monotone increasing one-parameter family of initial data starting with zero data, small values of the parameter lead to extinction, whereas large values of the parameter may lead to spreading, i.e., the solution converging locally uniformly to a positive spatially independent …

Structural Analysis And Auditing Of Snomed Hierarchies Using Abstraction Networks, Yue Wang

Dissertations

SNOMED is one of the leading healthcare terminologies being used worldwide. Due to its sheer volume and continuing expansion, it is inevitable that errors will make their way into SNOMED. Thus, quality assurance is an important part of its maintenance cycle.

A structural approach is presented in this dissertation, aiming at developing automated techniques that can aid auditors in the discovery of terminology errors more effectively and efficiently. Large SNOMED hierarchies are partitioned, based primarily on their relationships patterns, into concept groups of more manageable sizes. Three related abstraction networks with respect to a SNOMED hierarchy, namely the area taxonomy …

Advanced Intelligent Control And Optimization For Cardiac Pacemaker Systems, Wei Shi

Dissertations

Since cardiovascular diseases are major causes of morbidity and mortality in the developed countries and the number one cause of death in the United States, their accurate diagnosis and effective treatment via advanced cardiac pacemaker systems have become very important. Intelligent control and optimization of the pacemakers are significant research subjects. Serious but infrequently occurring arrhythmias are difficult to diagnose. The use of electrocardiogram (ECG) waveform only cannot exactly distinguish between deadly abnormalities and temporary arrhythmias. Thus, this work develops a new method based on frequency entrainment to analyze pole-zero characteristics of the phase error between abnormal ECG and entrained …

Instabilities In Newtonian Films And Nematic Liquid Crystal Droplets, Te-Sheng Lin

Dissertations

The instabilities of Newtonian films and nematic liquid crystal droplets within the framework of the long wave (lubrication) approximation are studied. For Newtonian films, it is found that, under destabilizing gravitational force, a contact line, modeled by a commonly used precursor film model, leads to free surface instabilities without any additional natural or imposed perturbations. In addition, there is a coupling between the surface instabilities and the transverse (fingering) instabilities which leads to complex behavior. All the observed phenomena are characterized by a single parameter D = (3Ca)^1/3 cot α where Ca is the capillary number and …

Investigation Of The Fracture Phenomena During The Milling Process Of Inorganic Particulates And Brittle Fracture Of Polymer Composites Using Fractal Theory, Zheng Qian

Dissertations

This dissertation investigates the applicability and usefulness of applying Fractal mathematics and to the fracture of brittle particulates in Fluid Energy Mill devices, and in particular quantifying the resulting power law particle size distributions, examining the Surface Fractal Dimension of milled particulates, and relating the Izod Impact Strength values of composites of polypropylene and Calcium carbonate particulates which are large un-milled, small milled, as well as small and produced by the simultaneous milling and coating with nano-silica to the Surface Fractal Dimension of the impact fracture surfaces.

First, the dissertation examines the behavior of un-coated and micron-sized wax pre-coated particulates …

Effects Of Information Importance And Distribution On Information Exchange In Team Decision Making, Babajide James Osatuyi

Dissertations

Teams in organizations are strategically built with members from domains and experiences so that a wider range of information and options can be pooled. This strategic team structure is based on the assumption that when team members share the information they have, the team as a whole can access a larger pool of information than any one member acting alone, potentially enabling them to make better decisions. However, studies have shown that teams, unlike individuals, sometimes do not effectively share and use the unique information available to them, leading to poorer decisions. Research on information sharing in team decision making …

Evolution Of 3-D Magnetic Topology In Flare-Productive Active Regions, Yixuan Li

Dissertations

Solar eruptive phenomena, such as flares and coronal mass ejections (CMEs), derive their energy from complex magnetic fields and are the principal source of disturbances that affect space weather. Although physical mechanism and dynamic morphology of flares have been a subject of intense research, many aspects of the flaring process still remain unclear. The objective of this dissertation is to advance the understanding of the physics behind solar flares based on observations, simulations and nonlinear force-free (NLFF) field modeling of magnetic fields.

The data used in this study are obtained from several ground-based or space-borne instruments, including BBSO/DVMG, Hinode/SOT/SP, SDO/HMI …

Registration And Categorization Of Camera Captured Documents, Venkata Gopal Edupuganti

Dissertations

Camera captured document image analysis concerns with processing of documents captured with hand-held sensors, smart phones, or other capturing devices using advanced image processing, computer vision, pattern recognition, and machine learning techniques. As there is no constrained capturing in the real world, the captured documents suffer from illumination variation, viewpoint variation, highly variable scale/resolution, background clutter, occlusion, and non-rigid deformations e.g., folds and crumples. Document registration is a problem where the image of a template document whose layout is known is registered with a test document image. Literature in camera captured document mosaicing addressed the registration of captured documents with …

The Incorporation Of Electrohydrodynamics And Other Modifications Into A Dry Spinning Model To Develop A Theoretical Framework For Electrospinning, Yuki Imura

Dissertations

The objective of this research was the development of a mathematical model of the electrospinning process using dry spinning modeling principles as a basis. This model is directed at the identification of parameters which influence final fiber characteristics, e.g., solvent concentration, temperature, spin line tension, and electric field. Preliminary computer simulations were performed; however, the generated data was inconclusive and was determined to be due in part to the complexity of the modeled system and the subsequent computational difficulties encountered. Although a comprehensive computational model of the electrospinning process has not yet been demonstrated, the theoretical development that was undertaken …

Virtual Reality Visual Feedback And Its Effect On Brain Excitability, Soha Saleh

Dissertations

This dissertation examines manipulation of visual feedback in virtual reality (VR) to increase excitability of distinct neural networks in the sensorimotor cortex. The objective is to explore neural responses to visual feedback of motor activities performed in complex virtual environments during functional magnetic resonance imaging (fMRI), and to identify sensory manipulations that could further optimize VR rehabilitation of persons with hemiparesis. In addition, the effects of VR therapy on brain reorganization are investigated. An MRI-compatible VR system is used to provide subjects with online visual feedback of their hand movement. First, the author develops a protocol to analyze variability in …

Transport Of Terrigenous Sediment And Horseshoe Crab Eggs In The Swash Zone Of An Estuarine Foreshore In Delaware Bay, New Jersey, Usa, Sherestha Saini

Dissertations

Identification of processes responsible for egg exhumation and transport in the swash zone is paramount to conservation of species that use the intertidal foreshore. One example where the understanding of these processes is critical to egg exhumation, transport and deposition is in Delaware Bay, USA. Beaches in Delaware Bay provide foraging grounds to many shorebird species that migrate thousands of miles from Central and South America to feed on nutrient rich horseshoe crab eggs during their peak spawning season. Eggs laid at depth by horseshoe crabs are exhumed and transported by bioturbation, wave and swash processes and made available to …

Energy Harvesting-Aware Design Of Wireless Networks, Fabio Iannello

Dissertations

Recent advances in low-power electronics and energy-harvesting (EH) technologies enable the design of self-sustained devices that collect part, or all, of the needed energy from the environment. Several systems can take advantage of EH, ranging from portable devices to wireless sensor networks (WSNs). While conventional design for battery-powered systems is mainly concerned with the battery lifetime, a key advantage of EH is that it enables potential perpetual operation of the devices, without requiring maintenance for battery substitutions. However, the inherent unpredictability regarding the amount of energy that can be collected from the environment might cause temporary energy shortages, which might …

Example Based Texture Synthesis And Quantification Of Texture Quality, Chandralekha De

Dissertations

Textures have been used effectively to create realistic environments for virtual worlds by reproducing the surface appearances. One of the widely-used methods for creating textures is the example based texture synthesis method. In this method of generating a texture of arbitrary size, an input image from the real world is provided. This input image is used for the basis of generating large textures. Various methods based on the underlying pattern of the image have been used to create these textures; however, the problem of finding an algorithm which provides a good output is still an open research issue. Moreover, the …

Adsorption Of Particles On Fluid-Liquid Interfaces, Bhavin Dalal

Dissertations

Particles floating on fluid-liquid interfaces are of considerable interest because of their importance in a range of physical applications and biological processes, e.g., self-- assembly of particles at fluid-fluid interfaces resulting in novel nano structured materials, stabilization of emulsions, formation of pollen and insect egg rafts, etc. The aim of this dissertation is to explore the mechanism by which particles are adsorbed at fluid-liquid interfaces. It is shown that the inertia of a particle plays an important role in its motion in the direction normal to a fluid-liquid interface, and in determining the particles adsorption trajectory and orientation in …

Vector Coprocessor Sharing Techniques For Multicores: Performance And Energy Gains, Spiridon Florin Beldianu

Dissertations

Vector Processors (VPs) created the breakthroughs needed for the emergence of computational science many years ago. All commercial computing architectures on the market today contain some form of vector or SIMD processing.

Many high-performance and embedded applications, often dealing with streams of data, cannot efficiently utilize dedicated vector processors for various reasons: limited percentage of sustained vector code due to substantial flow control; inherent small parallelism or the frequent involvement of operating system tasks; varying vector length across applications or within a single application; data dependencies within short sequences of instructions, a problem further exacerbated without loop unrolling or other …

Dispersibility Of And Adsorption On Functionalized Carbon Nanotubes, Susana Addo Ntim

Dissertations

As the applications of carbon nanotubes (CNTs) proliferate, mass production and widespread use of these nanocarbons will continue to rise. While raw, unrefined, and hydrophobic carbon nanotubes tend to settle out of aqueous media/environments, water dispersible, functionalized CNTs (F-CNTs) will contaminate water resources and will also be highly bioavailable on exposure. Therefore, there is a need to develop an understanding of the fate of F-CNTs in aqueous media.

The colloidal behavior of aqueous dispersions of F-CNTs formed via carboxylation and polymer wrapping with polyvinyl pyrrolidone (PVP) is investigated. The presence of polymer on the nanotube surface provides steric stabilization, and …

Mathematical Models Of Combustion At High Pressure, Daniel Fong

Dissertations

In this dissertation, we develop new mathematical theories of flame propagation that are valid at elevated, or extreme, pressures. Of particular interest is the regime of burning in which the pressure exceeds the critical pressure of the species undergoing chemical reaction. Fluids and flames are known to behave differently under these extreme conditions as opposed to atmospheric pressure. The focus of this dissertation is to investigate these differences by deriving reduced models that contain the unique features.

In the first part of this dissertation, we analyze the structure of laminar diffusion flames at high pressure in the limit of large …

Exploring The Nature Of High School Student Engagement With Science And Technology As An Outcome Of Participation In Science Journalism, Jennifer M.G. Hope

Dissertations

In a mixed-methods study of high school student participants in the National Science Foundation-funded Science Literacy through Science Journalism (SciJourn) project, the new Youth Engagement with Science & Technology (YEST) Survey and classroom case studies were used to determine program impact on participant engagement with science and technology as well as describe the experience of SciJourn students. Student engagement with science and technology is considered as a construct made up of three components: student action, interest, and identification. Analysis of quasi-experimental administration of the (YEST) Survey resulted in rejection of the hypotheses that SciJourn high school student participants would exhibit …

Assessing The Impact Participation In Science Journalism Activities Has On Scientific Literacy Among High School Students, Cathy Farrar

Dissertations

As part of the National Science Foundation Science Literacy through Science Journalism (SciJourn) initiative (http://www.scijourn.org; Polman, Saul, Newman, and Farrar, 2008) a quasi-experimental design was used to investigate what impact incorporating science journalism activities had on students’ scientific literacy. Over the course of a school year students participated in a variety of activities culminating in the production of science news articles for Scijourner (http://www.scijourner.org). Participating teachers and SciJourn team members collaboratively developed activities focused on five aspects of scientific literacy: contextualizing information, recognizing relevance, evaluating factual accuracy, use of multiple credible sources and information seeking processes. This study details the …

The Impact Of Teacher Certification Programs On Teacher Efficacy, Job Satisfaction, And Teacher Performance: A Comparison Of Traditional And Alternative Certification, Christopher Mark Mueller

Dissertations

The method selected to prepare and certify teachers continues to be a widely debated issue. Advocates for alternative certification (AC) contend that allowing content specialists from fields outside of education into the classroom will help meet the demand for teachers in hard-to-fill areas like math, science, and special education. Proponents of traditional teacher certification (TC) programs maintain that placing individuals without strong backgrounds in teaching methods, learning strategies, and child development will impede student achievement.

This study compared the levels of teacher efficacy, job performance and job satisfaction of teachers between AC (N = 164) and TC (N = 960) …

School Reform Initiatives: Their Impact On Teacher Burnout And Perceptions Of Efficacy, W. Wesley Cottongim

Dissertations

This study involving 2,478 teachers from south central Kentucky sought to determine the impact school improvement initiatives have on a teacher. More specifically, it explored how experiencing school improvement initiatives affect the measured levels of burnout and self-efficacy of a teacher.

Participants (n = 2,478) of this study came from school districts within the south central region of Kentucky. The participating districts were selected due to varying sizes of enrollments and the number of employed teachers. Participants were invited to participate in this study via an email invitation. Two previously published instruments were used. Participants were first asked to provide …

A University-Wide Student Support Program: Comparative View On Student Success, Kevin Patrick Thomas

Dissertations

Student support programs occur throughout the country in various forms at colleges and universities. The STEPS program at Western Kentucky University provides support to students who are required by state mandate to enroll in developmental or supplemental education courses. This program tracks the individual interventions utilized by students such as tutoring, intrusive advising, and supplemental education seminars. Through an analysis of retention and graduation data, this study compared the success of STEPS participants to eligible students who are non-participants of the program. The study also compared the STEPS participant population with eligible students within other four-year public Commonwealth of Kentucky …

Perceptions Of Kentucky Educators Concerning The Kentucky State Assessment System As An Accurate Reflection Of Student Learning, Benny C. Lile

Dissertations

While educational testing has been in place since the one room school house, it was not until the 1990s that accountability began to accompany assessment programs. With the passage of the No Child Left Behind Act (NCLB) in 2001, virtually every public school district in the United States of America that desired to continue to receive Title 1 funding found themselves tied to rigorous assessment and accountability systems. This focus on accountability has impacted every school, district, and state as they have sought to implement and deal with the consequences it has wrought. As the 50 states have sought to …

Function Estimation Of Irregularly Spaced Data With Long Memory Dependence, Rosalie Michelle Wheeler

Dissertations

We examine the problem of estimating an underlying function from collected data. The methods considered include parametric regression, density estimation, kernel estimation, wavelet regression, and specific results from when our underlying function f\left(x\right) is a member of the Besov or the Triebel spaces. Then we consider the problem of long memory error in several settings, including data which is equally spaced, data which is unequally spaced, and data which is a member of the Holder class and several other spaces. Ultimately we focus on three different problems. The first involves using linear interpolation or local averaging to account for the …

A Study Of The Relationship Between Nonverbal Kindergarten Ability And Third-Grade Reading Achievement, Aaron John Wills

Dissertations

Increased scrutiny of educational proficiency targets has intensified the urgency for educators to identify measurements that indicate students’ likelihood of eventual achievement in reading. This regression analysis explored the relationship between nonverbal ability in kindergarten as measured by the Naglieri Nonverbal Ability Test (NNAT) and eventual third-grade achievement in reading and writing as measured by the Missouri Assessment Program (MAP). Naglieri and Ronning (2000) found a range of correlational r values from .49 to .56 when comparing NNAT results to results from the Stanford Achievement Test 9 (SAT-9) in reading when tested concurrently at various grade levels. The present research …

Assessment Of A University Faculty Development Program On Speaking And Writing Pedagogy Through Direct Measurement Of Student Learning Outcomes, Julie Gissendanner Howdeshell

Dissertations

The purpose of this study was to assess a faculty development program through direct measurement of student learning outcomes through investigating the relationship between participation in a faculty development program on speaking and writing pedagogy and student learning outcomes in oral and written communication. Faculty and students enrolled in senior capstone courses in Spring 2011 were asked to participate as part of requirements for internal assessment and external accreditation. Of the 1,448 students enrolled in capstone courses that semester, 1,002 papers and 727 recordings were received, representing 69% and 50% of those enrolled respectively. A sample of 400 papers and …

Home-School Collaboration: Concurrent Home And School Reading Interventions Within A Response To Intervention System, Qi Zhou

Dissertations

The current study investigated the effectiveness of reading interventions in the form of home-school collaboration on increasing oral reading fluency in elementary students exhibiting reading fluency deficits. Specifically, student participants were receiving Tier II reading interventions at their school. Additionally, parents were trained to implement an individualized intervention identified by brief experimental analysis with each student at home. Home-school notes were used to facilitate support and communication between the home and school. Results demonstrated that three of four students’ oral reading fluency improved. Furthermore, parents rated the interventions as acceptable. Parent treatment integrity was found to be adequate.

The Relationship Between Academic Achievement And School-Based Mental Health Services For Middle School Students, Lisa Ogle Williams

Dissertations

Mental health issues among American adolescents and children can negatively impact their potential for school success. As many as 10% of students among the general education population suffer from psychiatric disorders, yet only between 1% and 5% of those students are being served. The effects of mental health difficulties are problematic for students because they negatively impact academic performance, behavior, attendance, and school violence (Whelley, Cash, & Bryson, 2003). There are often barriers to academic performance relative to psychiatric illness and problems that include inadequate health insurance coverage, lack of transportation, shortages of child mental health professionals, and stigmas associated …

Do At-Risk Students Benefit When Novanet Is Used For Credit Recovery?, Rebecca Lynn Volkerding

Dissertations

The purpose of this study was to determine if it is effective and appropriate to place all students needing credit recovery in computer-based classes regardless of age, risk ratio, and their previous failing grade. Driven by the NCLB mandate for schools to produce greater gains and graduate all students in 4.5 years, districts are now using online credit recovery programs to help at-risk students gain promotion and put students back on-track for graduation without placing these students back in the traditional classroom setting where they failed the class the first time. Although there is an adequate knowledge base about the …

A Study Of Satp Scores And Principals’ Perceptions For Traditional And Alternate Routes To Teacher Certification, Eddie Eugene Moore

Dissertations

This study explores the differences between traditional and alternate route certification by focusing on the achievement of students who have been instructed by teachers from each program. In addition, this study identifies the strengths and weaknesses of teachers from each certification route through surveys and interviews with principals in the sample. Previous studies on this subject have focused on elementary or middle schools, which limits the information available for the high school level. This study was directed toward high school teachers in core subject areas tested in Mississippi’s accountability model. The purpose of this study was to connect student test …