Digital Commons Network^™

Finite Element Analysis Of Cancellous Bone, Lucas T. Wilkerson

Theses and Dissertations--Mechanical and Aerospace Engineering

A variety of pathologies exist which increase the likelihood of bone fracture. Present methods for determining the fracture risk of a specific patient are based exclusively on the amount of bone present. While the quantity of bone tissue is correlated with strength, it neglects to account for bone’s intricate microarchitecture. To assess the effect of bone quality on strength, a methodology was developed for the structural analysis of cancellous bone biopsies. Thirty biopsies were selected from a pre-existing biopsy bank, and scanned using a SCANCO µCT-40 at a resolution of 30 microns. Cortical bone was removed from the resulting three-dimensional …

Low Reynolds Number Flow Field Modification Via Travelling Wave Actuation Of A Vertically Aligned Wire Array Surface, John C. Calhoun

Theses and Dissertations--Mechanical and Aerospace Engineering

Experiments were conducted to observe the effects of an active wire surface on low-Reynolds number Poiseuille flow. The objective was to evaluate the feasibility of actuating piezoelectric nanowires into a travelling wave motion in order to reduce wall shear stress in turbulent flows. Studies have shown that travelling wave motions introduced into the bounding wall of turbulent flow can reduce wall shear stress by disrupting the formation of drag-inducing coherent vortical structures. A Reynolds number scaled flow facility was designed to represent the near-wall region of turbulent flow. A wire surface was installed in the bounding wall and dynamically actuated …

Applying Specific Arts Activities To Improve The Quality Of Life For Individuals With Alzheimer’S Disease And Dementia, Ann Christianson Tietyen

Theses and Dissertations--Art and Visual Studies

This study examined the effectiveness of a combination of seven different visual art activities, hat decoration, collage, embossing, painting, ceramics, photography, and printmaking, on quality of life for eight veterans with Alzheimer’s disease and dementia. The eight veterans were selected from the population of residents at the Thomson‐ Hood Veterans facility in Wilmore, Kentucky. These veterans were administered the seven art activities mentioned above, which ranged from less difficult to increasing difficulty. Three standard self‐reporting instruments, the Quality of Life‐AD, the Rosenberg Self‐Esteem Scale, and the Smiley‐Face Mood Assessment, as well as systematic observation and surveys were used to explore …

Localization And Functional Characterization Of Oatp4c1 Transporter In In Vitro Cell Systems And Human/Rat Tissues, Kuei-Ling Kuo

Theses and Dissertations--Pharmacy

The organic anion transporting polypeptide 4c1 (Oatp4c1) was previously identified as a novel uptake transporter predominantly expressed at the basolateral membrane in the rat kidney proximal tubules. Its functional role was suggested to be a vectorial transport partner of an apically-expressed efflux transporter for the efficient translocation of physiological substrates into urine, some of which were suggested to be uremic toxins. In vitro studies in polarized cell lines showed that upon transfection rat Oatp4c1 localizes at the apical membrane. The objectives of this project were to further validate the subcellular localization of Oatp4c1/OATP4C1 in rat and human tissues as well …

The Transmission Dynamics Of Equine Herpesvirus Type 1 (Ehv-1) Infection In Outbreaks Characterized Predominately By Neurologic Or Respiratory Illness, Barry Jay Meade

Theses and Dissertations--Veterinary Science

Formalized epidemiological field investigations were conducted to compare and contrast the transmission dynamics of EHV-1 neurological disease among horses stabled at Churchill Downs Racetrack, Louisville, Kentucky and of EHV-1 respiratory illness among horses stabled in the student barn at Murray State University. Differences were assessed by means of statistical and mathematical modeling techniques applied to survey and biological data collected over the course of the respective disease events.

Regression methods applied to survey data enabled the construction of a statistical model to predict a date of onset of illness for horses within each equine cohort. Comparisons of the epidemic curves …

Improving Model Performance Using Season-Based Evaluation, Misgana Muleta

Civil and Environmental Engineering

Computer models have become vital decision-making tools in many areas of science and engineering including water resources. However, models should be properly evaluated before use to improve the likelihood of making sound decisions based on their results. The model evaluation technique practiced today in hydrology assumes that model parameters are season insensitive and attempts to identify “optimal” values that would describe watershed behavior during dry and wet seasons. This assumption could compromise accuracy of model predictions. This study demonstrates performance improvement that would be achieved when a season-based model evaluation approach is pursued. A global sensitivity analysis (SA) model has …

Self-Regulation: The Link Between Academic Motivation And Executive Function In Urban Youth, Sara Ferry Walker

PCOM Psychology Dissertations

The present study investigated the relationship between academic motivation and executive function skills through teacher reports of prototypical students, perceived to lack motivation. Second, the study examined the effect of grade level (i.e., elementary, middle, high) on both teacher-perceived academic motivation and executive function skills for these prototypical students. It was hypothesized that there were significant relationships between executive function processes and academic motivation. It was also hypothesized that due to the decline in academic engagement during adolescence, middle school and high school teachers would perceive higher levels of executive dysfunction and deficits in academic motivation than would elementary teachers. …

Optical Mode Pattern Study Of Gan Based Leds With And Without Nanoscale Top Grating, Gregory Chavoor

Electrical Engineering

This study analyzes optical confinement factor and light emitting mode order for three different GaN LEDs: a conventional LED, thin Film LED, and thin Film LED with a photonic crystal (PhC) grating. For the first structure, we increase the thickness of Al_xGa_1-xN from 0 to 600nm, alter the x composition in Al_xGa_1-xN from 0.05 to 0.2 in steps of 0.05, and adjust the p-GaN and n-GaN thicknesses each from 0 to 200nm. For the second structure, we alter the n-GaN substrate thickness from 300-1000nm in steps of 100nm and 1000-4000nm in steps …

Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, Umesh K. Haritashya

Department of Earth, Environment and Sustainability Faculty Publications

Meltwater runoff modeling from glacierized basins needs several input data, including total meltwater contributing area. This study utilizes optical remote sensing data to assess glacierized basins in the central Himalayas where snow and glaciers contribute substantially to the water resources. Result shows that there are four main water-bearing zones in the basin: (a) dry snow, (b) wet snow, (c) exposed glacial ice, and (d) debris-covered glacial ice, and it is possible to differentiate and map these zones and their spatio-temporal variations from satellite sensor data. These zones can then be incorporated in meltwater runoff modeling as separate entities because they …

2012 Alumni Presenters, University Of Dayton. Department Of Mathematics

Biennial Alumni Seminar

No abstract provided.

A Meshless Numerical Solution Of The Family Of Generalized Fifth-Order Korteweg-De Vries Equations, Syed Tauseef Mohyud-Din, Elham Negahdary, Muhammad Usman

Mathematics Faculty Publications

In this paper we present a numerical solution of a family of generalized fifth-order Korteweg-de Vries equations using a meshless method of lines. This method uses radial basis functions for spatial derivatives and Runge-Kutta method as a time integrator. This method exhibits high accuracy as seen from the comparison with the exact solutions.

Existence And Uniqueness Conditions For A Class Of (K+4j)-Point N-Th Order Boundary Value Problems, Paul W. Eloe, Johnny Henderson, Rahmat Ali Khan

Mathematics Faculty Publications

No abstract provided.

A Leggett-Williams Type Theorem Applied To A Fourth Order Problem, Richard Avery, Paul Eloe, Johnny Henderson

Mathematics Faculty Publications

We apply an extension of a Leggett-Williams type fixed point theorem to a two-point boundary value problem for a fourth order ordinary differential equation. The fixed point theorem employs concave and convex functionals defined on a cone in a Banach spstce. Inequalities that extend the notion of concavity to fourth order differential inequalities are derived and employed to provide the necessary estimates. Symmetry is employed in the construction of the appropriate Banach space.

Bounded Solutions Of Almost Linear Volterra Equations, Muhammad Islam, Youssef Raffoul

Mathematics Faculty Publications

Fixed point theorem of Krasnosel’skii is used as the primary mathematical tool to study the boundedness of solutions of certain Volterra type equations. These equations are studied under a set of assumptions on the functions involved in the equations. The equations will be called almost linear when these assumptions hold.

Creating Macroscopes With Technology And Analytics: New Possibilities In Our Lives – The Important Role Of Tomorrow’S Mathematics Professionals (Abstract), Lilian S. Wu

Kenneth C. Schraut Memorial Lectures

Our world is increasingly computerized, interconnected, and instrumented with sensors. Massive amounts of data are being captured in computer systems about our natural environment and man-made engineered structures, processes, and systems. But it is necessary to make sense out of all this data. With new computer methods computers can in effect become macroscopes, enabling us to see the world portrayed by our data.

Thirteenth Kenneth C. Schraut Memorial Lecture (Poster), University Of Dayton. Department Of Mathematics

Kenneth C. Schraut Memorial Lectures

No abstract provided.

Synthesis And Flame Retardant Testing Of New Boronated And Phosphonated Aromatic Compounds, Vladimir Benin, Sravanthi Durganala, Alexander Morgan

Chemistry Faculty Publications

The present report describes the preparation and use of some dimethyl terephthalate derivatives in transition metal-catalyzed coupling reactions to produce new reactive flame retardants. Dimethyl iodoterephthalate and dimethyl 2,5-diiodoterephthalate were successfully employed in the preparation of phosphonic and boronic esters and acids. The latter were tested for heat release with a microcombustion calorimeter (ASTM D7309) to determine the potential for heat release reduction of these flame retardant molecules. The results showed that the addition of boronic or phosphonic acids greatly lowered the heat release, due to a condensed phase (char formation) mechanism. Adding ester groups to the boronic acids or …

Towards Evolving More Brain-Like Artificial Neural Networks, Sebastian Risi

Electronic Theses and Dissertations

An ambitious long-term goal for neuroevolution, which studies how artificial evolutionary processes can be driven to produce brain-like structures, is to evolve neurocontrollers with a high density of neurons and connections that can adapt and learn from past experience. Yet while neuroevolution has produced successful results in a variety of domains, the scale of natural brains remains far beyond reach. In this dissertation two extensions to the recently introduced Hypercube-based NeuroEvolution of Augmenting Topologies (HyperNEAT) approach are presented that are a step towards more brain-like artificial neural networks (ANNs). First, HyperNEAT is extended to evolve plastic ANNs that can learn …

Setpad: A Sketch-Based Tool For Exploring Discrete Math Set Problems, Travis Cossairt

Electronic Theses and Dissertations

We present SetPad, a new application prototype that lets computer science students explore discrete math problems by sketching set expressions using pen-based input. Students can manipulate the expressions interactively with the tool via pen or multi-touch interface. Likewise, discrete mathematics instructors can use SetPad to display and work through set problems via a projector to better demonstrate the solutions to the students. We discuss the implementation and feature set of the application, as well as results from both an informal perceived usefulness evaluation for students taking a computer science foundation exam in addition to a formal user study measuring the …

Networking And Security Solutions For Vanet Initial Deployment Stage, Baber Aslam

Electronic Theses and Dissertations

Vehicular ad hoc network (VANET) is a special case of mobile networks, where vehicles equipped with computing/communicating devices (called "smart vehicles") are the mobile wireless nodes. However, the movement pattern of these mobile wireless nodes is no more random, as in case of mobile networks, rather it is restricted to roads and streets. Vehicular networks have hybrid architecture; it is a combination of both infrastructure and infrastructure-less architectures. The direct vehicle to vehicle (V2V) communication is infrastructure-less or ad hoc in nature. Here the vehicles traveling within communication range of each other form an ad hoc network. On the other …

Modeling Annual Water Balance In The Seasonal Budyko Framework, Negin Alimohammadi

Electronic Theses and Dissertations

In this thesis, the role of soil water storage change on the annual water balance is evaluated based on observations at a large number of watersheds located in a spectrum of climate regions, and an annual water balance model is developed at the seasonal scale based on Budyko hypthesis. The annual water storage change is quantified based on water balance closure given the available data of precipitation, runoff, and evaporation estimated from remote sensing data and meteorology reanalysis. The responses of annual runoff, evaporation, and storage change to the interannual variability of precipitation and potential evaporation are then analyzed. Both …

An Assessment Of Ecological Processes In The Apalachicola Estuarine System, Florida, Daina Smar

Electronic Theses and Dissertations

The following is a compilation of field data collected in 2011 and 2012 in Apalachicola, FL as part of a five year study assessing the ecological effects of sea level rise in the northern Gulf of Mexico. Many coastal communities, both natural and developed, will soon be working to mitigate the effects of sea level rise, if they are not already doing so. This thesis investigates the natural patterns of the Apalachicola estuarine system through the collection and analysis of in situ water, sediment, and biomass samples. Additionally, results of the field samples are presented and recommendations for additional sampling …

Algorithms For Rendering Optimization, Jared Johnson

Electronic Theses and Dissertations

This dissertation explores algorithms for rendering optimization realizable within a modern, complex rendering engine. The first part contains optimized rendering algorithms for ray tracing. Ray tracing algorithms typically provide properties of simplicity and robustness that are highly desirable in computer graphics. We offer several novel contributions to the problem of interactive ray tracing of complex lighting environments. We focus on the problem of maintaining interactivity as both geometric and lighting complexity grows without effecting the simplicity or robustness of ray tracing. First, we present a new algorithm called occlusion caching for accelerating the calculation of direct lighting from many light …

Computational Methods For Analyzing Rna Folding Landscapes And Its Applications, Yuan Li

Electronic Theses and Dissertations

Non-protein-coding RNAs play critical regulatory roles in cellular life. Many ncRNAs fold into specific structures in order to perform their biological functions. Some of the RNAs, such as riboswitches, can even fold into alternative structural conformations in order to participate in different biological processes. In addition, these RNAs can transit dynamically between different functional structures along folding pathways on their energy landscapes. These alternative functional structures are usually energetically favored and are stable in their local energy landscapes. Moreover, conformational transitions between any pair of alternate structures usually involve high energy barriers, such that RNAs can become kinetically trapped by …

Systems Analysis For Urban Water Infrastructure Expansion With Global Change Impact Under Uncertainties, Cheng Qi

Electronic Theses and Dissertations

Over the past decades, cost-effectiveness principle or cost-benefit analysis has been employed oftentimes as a typical assessment tool for the expansion of drinking water utility. With changing public awareness of the inherent linkages between climate change, population growth and economic development, the addition of global change impact in the assessment regime has altered the landscape of traditional evaluation matrix. Nowadays, urban drinking water infrastructure requires careful long-term expansion planning to reduce the risk from global change impact with respect to greenhouse gas (GHG) emissions, economic boom and recession, as well as water demand variation associated with population growth and migration. …

Detecting, Tracking, And Recognizing Activities In Aerial Video, Vladimir Reilly

Electronic Theses and Dissertations

In this dissertation, we address the problem of detecting humans and vehicles, tracking them in crowded scenes, and finally determining their activities in aerial video. Even though this is a well explored problem in the field of computer vision, many challenges still remain when one is presented with realistic data. These challenges include large camera motion, strong scene parallax, fast object motion, large object density, strong shadows, and insufficiently large action datasets. Therefore, we propose a number of novel methods based on exploiting scene constraints from the imagery itself to aid in the detection and tracking of objects. We show, …

Optimization Of Process Parameters For Faster Deposition Of Cuin1-Xgaxs2 And Cuin1-Xgaxse2-Ysy Thin Film Solar Cells, Ashwani Kaul

Electronic Theses and Dissertations

Thin film solar cells have the potential to be an important contributor to the world energy demand in the 21st century. Among all the thin film technologies, CuInGaSe2 (CIGS) thin film solar cells have achieved the highest efficiency. However, the high price of photovoltaic (PV) modules has been a major factor impeding their growth for terrestrial applications. Reduction in cost of PV modules can be realized by several ways including choosing scalable processes amenable to large area deposition, reduction in the materials consumption of active layers, and attaining faster deposition rates suitable for in-line processing. Selenization-sulfurization of sputtered metallic Cu-In-Ga …

Complex-Valued Adaptive Digital Signal Enhancement For Applications In Wireless Communication Systems, Ying Liu

Electronic Theses and Dissertations

In recent decades, the wireless communication industry has attracted a great deal of research efforts to satisfy rigorous performance requirements and preserve high spectral efficiency. Along with this trend, I/Q modulation is frequently applied in modern wireless communications to develop high performance and high data rate systems. This has necessitated the need for applying efficient complex-valued signal processing techniques to highly-integrated, multi-standard receiver devices. In this dissertation, novel techniques for complex-valued digital signal enhancement are presented and analyzed for various applications in wireless communications. The first technique is a unified block processing approach to generate the complex-valued conjugate gradient Least …

Effluent Water Quality Improvement Using Silt Fences And Stormwater Harvesting, Ikiensinma Gogo-Abite

Electronic Theses and Dissertations

Construction sites are among the most common areas to experience soil erosion and sediment transport due to the mandatory foundation tasks such as excavation and land grubbing. Thus, temporary sediment barriers are installed along the perimeter to prevent sediment transport from the site. Erosion and sediment transport control measures may include, but not limited to, physical and chemical processes such as the use of a silt fence and polyacrylamide product. Runoff from construction sites and other impervious surfaces are routinely discharged into ponds for treatment before being released into a receiving water body. Stormwater harvesting from a pond for irrigation …

Effects Of Allotropic Transformations On Interdiffusion Behavior In Binary Systems, Ashley Elizabeth Ewh

Electronic Theses and Dissertations

Diffusion plays a significant role in most materials systems by controlling microstructural development. Consequently, the overall properties of a material can be largely dependent upon diffusion. This study investigated the interdiffusion behavior of three binary systems, namely, Mo-Zr, Fe-Mo, and Fe-Zr. The main interest in these particular metals is for application in nuclear fuel assemblies. Nuclear fuel plates generally consist of two main components which are the fuel and the cladding. Due to diffusional interactions that can occur between these two components, a third is sometimes added between the fuel and cladding to serve as a diffusion barrier layer. Fe, …