Digital Commons Network^™

Development Of Composite Honeycomb Protective Structures For Above-Ground Steel Storage Tanks Against Wind-Borne Debris, Tamara Grooms Baker

Dissertations

Within the civil engineering industry, the evaluation of a retro-fit system or more- specifically, a post-installed, glass fiber reinforced polymer and honeycomb system over steel is evaluated on how this retro-fit system can help minimize impact and critical kinetic energy onto steel storage tanks caused from wind-borne debris to structures in hurricane prone regions. Determining an accurate formula for critical kinetic energy for steel has also been an on-going process in our industry for over 200 years. This research helps to get one-step closer to accurately determining a valid equation. Existing theories and equations of critical kinetic energy have been …

Measuring And Evaluating Directional Textures And Using Them In Visual Discovery, Manil Maskey

Dissertations

This dissertation focuses on three aspects of directional textures. The first aspect is the development of a new directional texture-based visualization technique to address challenges in visualizing multivariate data in a single display. The technique uses a multi level Markov Random Field-based texture synthesis to progressively generate a visualization that encodes data variables using various texture features, especially texture direction. Since texture directionality has not been used extensively in visualization, this technique provides a new visual cue to display additional data variable in a single display. Evaluations of the new texture-based visualization technique are also presented. The second aspect is …

Parallel Implementation Of Resampling Methods For Particle Filtering On Graphics Processing Units, Matthew A. Nicely

Dissertations

Particle filter techniques are common methods used to estimate the evolving state of nonlinear, non-Gaussian time-variant systems by utilizing a periodic sequence of noisy measurements. The accuracy of particle filtering has often been shown to be superior to other state estimation techniques, such as the extended Kalman filter (EKF), for many applications. Unfortunately, the high computational cost and highly nondeterministic run-time behavior of particle filters often precludes their use in hard, real-time environments where filter response must meet the strict timing requirements of the application. Particle filter algorithms are composed of three main stages: prediction, update, and resampling. General purpose …

Short-Range Phase Coded Linear Frequency Modulation Waveform Radar Design And Analysis, Jason M. Reneau

Dissertations

This dissertation presents the design and analysis of a short range radar sensor that utilizes a novel compound waveform. Compound waveforms consist of a combination of more than one type of traditional radar waveform. Unique to this work is the manner in which the phase of the compound waveform composed of linear frequency modulation and bi-phase code modulations are combined. The phase of the modulations is combined on an intra pulse basis with the sweep duration of the linear frequency modulation matched to the period of the bi-phase code. The frequency bandwidths of the component modulations are also matched. Combining …

Hybrid Impulsive Higher Order Sliding Mode Control, Fathi Muhammad Aldukali

Dissertations

A hybrid-impulsive second order/higher order sliding mode (2- SMC/HOSM) control is explored in order to reduce dramatically the convergence time practically to zero, achieving instantaneous (or short time) convergence and uniformity. For systems of relative degree 2, the impulsive portion of the control function drives the system’s output (the sliding variable) and it’s derivative to zero instantaneously (or in short time) achieving a uniform convergence. Then the discontinuous state or output feedback stabilizes system’s trajectory at the origin (or its close vicinity), while achieving the ideal or real second order sliding mode (2-SM). The Lyapunov analysis of the considered hybrid-impulsive-discontinuous …

Physically Derived Two-Dimensional Predictive Model For Dual-Gate Devices Using Quintic Splines, Scott C. Wolfson

Dissertations

This dissertation presents the first ever application of quintic splines in the development of a dual-gate Metal Oxide Semiconductor Field Effect Transistor (MOSFET) model based on the well-known drift-diffusion system of differential equations. The techniques and methodologies presented advance the current state of the art in this particular area by implementing improved two-dimensional numerical techniques and limiting the use of common accuracy reducing assumptions intended to decrease semiconductor equation complexity and simulation execution time. This results in the first known two-dimensional physics based model that uses this numerical technique, is valid in all regions of operation, includes Non-Quasi Static transient …

A Theoretical Evaluation Of Engineering Conceptual Design Methodologies, John M. Nicholson

Dissertations

Much of Systems Engineering (SE) involves heuristic tools and rules of thumb to aid the engineer in making decisions. Practicing engineers rely on these heuristic methods to manage risk, plan and perform tests, plan projects and design products. Product design is the focus of this research. Numerous product design methods in practice utilize heuristics and simplifying assumptions to ease the burden on the design engineer. However, do engineers pay a price for these simplifications? To understand the impact of design methods, a normative design framework is developed based on a rigorous consideration of Decision Theory and Social Choice Theory. Engineers …

Solar Energetic Particles Transport In Meandering Magnetic Field, Ashraf Moradi

Dissertations

No abstract provided.

Development Of Absorption-Coefficient-Based Narrow-Band Model And Its Application To The Calculation Of Radiative Heat Transfer In One And Two-Dimensional Enclosures, Annette Fisher

Dissertations

A narrow band model (NBM) with the absorption coefficient as the fundamental radiative property is investigated so that numerical solution methods compatible with the differential form of the radiative transfer equation (RTE) may be employed. The advantage of a NBM based on the absorption coefficient rather than the transmissivity is that the expression for the mean absorption coefficient is independent of the functional form of the probability density function for spectral line intensities, P(S). Accordingly, it is seen that the narrow-band mean absorption coefficient κ_η=^S/_d, where S and d are the mean line …

Control Of Emission Dynamics Of Quantum Dots Via Plasmonic Nanostructures And Lattices, Rithvik R. Gutha

Dissertations

No abstract provided.

Study Of Effects Of Rigid Body Vibrations On External Hypersonic Flow Using Smoothed Particle Hydrodynamics, Tyler Englestad

Dissertations

Vibrations plague wind tunnel data and are caused by several factors, such as sensor placement, flow inconsistencies due to imperfect collimation, and the sub-scale model mechanically vibrating upon its mounting apparatus, called a sting. This study focuses on the latter source, particularly at hypersonic velocities, due to fundamental changes that occur within the flow at these speeds. These flow changes differ from those at lower velocities, where the mechanical vibrations are generally superimposed upon the data and thus are easily remove via notch or band-stop filtering. Therefore, traditional post-processing noise removal techniques are not as effective. This dissertation presents an …

Technical Reviews In Complex Development Programs, Robert M. Braunger

Dissertations

Technical reviews in major complex defense and space projects are high-stakes events that technically assess programs costing up to billions of dollars, probing the work of hundreds of engineers. These technical reviews evolved since the 1960s into an industry-standard systems engineering process. Prior research argues that technical reviews at the subsystem level are the most technically important---conflicting with other work positing that mission-level technical reviews critically contribute to failures of government programs. Reviews are important, but research on reviews is inconsistent, fragmented, and lacks supporting data. To understand the practice of technical reviews and the alignment between practice and literature, …

Characterization Of Putative Peptidyl-Trna Hydrolase Domain Containing 1, Geordan L. Burks

Dissertations

Putative peptidyl-tRNA hydrolase domain containing 1 (PTRHD1) is a eukaryotic protein predicted to be a Pth2-like peptidyl-tRNA hydrolase. Peptidyl-tRNA hydrolases (Pth) perform the essential function of recycling tRNA from peptidyl-tRNA in the event of translational failure. This function is ubiquitous in all domains of life. Homologues of bacterial (Pth1) and archaeal (Pth2) Pths are present in eukaryotes; however, simultaneous knockout of Pth1 and Pth2 has no effect on cell viability, suggesting the presence of additional proteins in eukaryotes that contain Pth activity. PTRHD1 was proposed as one such eukaryotic Pth and was tested for Pth hydrolase activity. While PTRHD1 did …

Understanding The Significant Disparity Between Observations And Cmip5 Model Simulations At The Ocean/Atmosphere Interface In The Tropics, Robert Anthony Junod

Dissertations

Observations indicate that the warming of the tropical atmosphere is proceeding at a rate significantly less than depicted in model projections. Surface energy fluxes play a central role in the coupling of the atmosphere and ocean components which impact tropospheric temperature. In order to investigate the atmospheric temperature disparity, this study examines the near-surface air temperature and surface energy fluxes at the ocean-atmosphere interface using a suite of Coupled Model Intercomparison Project 5 (CMIP5) models, comparing their output with observations. Observations are used to test model fidelity with respect to the surface energy fluxes (net shortwave, net longwave, latent heat …

Three-Dimensional Modeling Of Fusion Yield In Plasma Jet-Driven Magneto-Inertial Fusion, Kevin John Schillo

Dissertations

Controlled nuclear fusion in a laboratory is a challenging problem. After more than half a century of research, no fusion reactor has been developed that is capable of generating more energy than what is required to operate the reactor. Creating accurate simulations of the fusion plasma conditions at peak compression is crucial to guide the development of future fusion experiments and ultimately determine what is necessary to create a viable fusion reactor. This dissertation presents an investigation into three-dimensional simulations of neutron and alpha particle yield of deuterium-tritium fusion. An overview of the physics of nuclear fusion presents the attractive …

Study Of Plume Dynamics From Laser-Ablated Elemental Materials For Propulsion Application, M. Shane Thompson

Dissertations

The efficacy of utilizing material ablation from picosecond laser pulses onto elemental metal targets for propulsion applications is studied by a variety of measurement methods to characterize laser ablation plume dynamics. A 100 ps, 532 nm laser is used for ablating elemental metals, and the resulting ablation plume dynamics are measured by time-of-flight (TOF) energy analyzer probes, a piezoelectric force sensor, and an intensified imager. Results indicate that plume dynamics exhibit a material dependence and behave in a manner indicative of laser-induced plasma formation and expansion, and indicate that ablation-based laser propulsion is characterized by high specific impulses (on the …

Development Of Carbon Reinforced High Performance Cementitious Composites (Crhpc²) For Reverse Bending, Matthew Pinkston

Dissertations

Cementitious composites offer design flexibility and can be tailored to a variety of applications. However, when used in unique and structurally demanding situations, consistent performance is critical. The objectives of this study are: 1) to develop a new class of lightweight cementitious composites that exhibit consistent structural performance and 2) to introduce novel methods for their construction. These, so-called Carbon Reinforced High Performance Cementitious Composites (CRHPC2), are envisioned for uses ranging from aerospace and lightweight construction to energy transfer and structural morphing. Beams are fabricated by placing lightweight (776-806 kg/m3), high-performance cementitious matrices having low flexural moduli (776-913 MPa) over …

Ion-Atom Charge-Exchange Collisions And Their Effect On Plasma-Neutral Coupling, Anthony M. Destefano

Dissertations

The heliosphere is a cavity carved out of the interstellar medium by the supersonic outflow of solar wind (SW) from the Sun. The local interstellar medium (LISM) is partially ionized with the neutral particles penetrating the heliosphere unimpeded by the electric and magnetic (EM) fields. In order to model the heliosphere, both a magnetohydrodynamic (MHD) and a kinetic Boltzmann (or fluid) approach should be used to represent the plasma and neutral particles, respectively. Even though neutral particles are unaffected by EM fields, certain collisions that exchange charge between ions do occur called charge-exchange. This charge-exchange process, in the form of …

Detection Of Offensive Youtube Comments, A Performance Comparison Of Deep Learning Approaches, Priyam Bansal

Dissertations

Social media data is open, free and available in massive quantities. However, there is a significant limitation in making sense of this data because of its high volume, variety, uncertain veracity, velocity, value and variability. This work provides a comprehensive framework of text processing and analysis performed on YouTube comments having offensive and non-offensive contents.

YouTube is a platform where every age group of people logs in and finds the type of content that most appeals to them. Apart from this, a massive increase in the use of offensive language has been apparent. As there are massive volume of new …

A Look Inside The Black Box: Understanding Communicative Exchanges In Online Learning Environments, Sara Douglas

Dissertations

Participation in academic discussions and peer collaboration activities is instrumental to student engagement, motivation, and mastery of course content. These activities also improve 21st century skills, such as listening, managing diverse viewpoints, and communicating effectively. Although online learning options in the United States have dramatically increased in the past decade, there is limited evidence that online high school courses offer sufficient opportunities for students to communicate and collaborate with teachers and peers. The purpose of this mixed-methods study seeks to find out if, how, and why students interact with others in online courses. Findings from observations of five high school …

The Contribution Of P. G. Wodehouse To The Field Of Gastronomy Through His Character, The French Chef, Anatole, Elizabeth Wilson

Dissertations

In her paper ‘A Cultural Field in the Making: Gastronomy in 19th-Century France’, Priscilla Parkhurst Ferguson argues that the field of gastronomy came into existence in the middle of the nineteenth century in France. This field of gastronomy was constructed from two elements, the significance that gastronomy, defined at the time as a structured set of culinary practices, had attained in France by the nineteenth century, but also, the contribution of writers of culinary discourse who wrote about this gastronomy. These writers came from different disciplines and included the realist fiction writer Honoré de Balzac (1799-1850), whose work Ferguson describes …

Angels And Sub-Divine Supernatural Beings: Their Characteristics, Function, And Relationship To God And Humanity In Deuteronomy-Kings, Joni Amanda Mcguire-Moushon

Dissertations

This research analyzes selected passages in Deuteronomy-Kings in order to determine the characteristics and roles of supernatural sub-divine beings within these books. Then this data is compared with the angelology of the Second Temple period in order to identify the similarities and the extent of the differences between them.

Deuteronomy contains references to supernatural sub-divine beings, such as “demons” and “holy one(s)”. While Deuteronomy affirms the existence of sub-divine beings, it forbids the Israelites to worship them. In the books of Joshua and Judges, there is awareness of supernatural beings and their roles as warriors, messengers, and tormentors. However, in …

Variations In Individualistic And Collectivistic Cultural Orientation And The Protective Factors That Contribute To Resilience: Comparisons From Jamaica, Rwanda, And The United States, Stacey Nicely

Dissertations

Problem

Despite the advancement in resilience research, and although mental health professionals are encouraged to become culturally competent, it is still unclear how I/C cultural orientation influence various protective factors that contribute to resilience. Individualists emphasize independence and autonomy while collectivists emphasize interdependence and in-group consensus (Hofstede, 1991; Markus & Kitayama, 1991). Therefore, it is expected that the protective factors that promote resilience will also operate differently for individualists as compared to collectivists (Triandis, 1995). Yet, mental health practitioners have very little information available to them to guide their intervention efforts with individualists and collectivists. When practitioners work with individuals …

Examining Perceptions Of Service Quality Of Student Services And Satisfaction Among International Students At Universities In Indiana And Michigan, Mordekai Ochieng Ongo

Dissertations

Problem

Universities in the United States face financial constraints, intense competition for students, declining student enrollment, and constant student attrition. However, an increasing number of international students seek higher education abroad, especially in the U.S. Providing quality services to these international students might help institutions attract and retain more of them. Unfortunately, little empirical research has been done on international students’ perceptions of service quality, especially of non-academic services. This study fills that gap by using a modified SERVPERF questionnaire to investigate international students perceived service quality and satisfaction at eight universities in Indiana and Michigan.

Method

The purpose of …

The Influence Of Pornography Consumption, Religiosity, And Family Sexual Communication On Emerging Adults' Engagement In Hookup Culture In The United States, Angie Powels Horner

Dissertations

Purpose

The primary purpose of the current research was to understand the influence of considerable social-cultural factors, including pornography consumption, religiosity, and family sexual communication, on the sexual values and behaviors of the emerging adult population. Particularly, how pornography consumption, religiosity, and family sexual communication influence emerging adult engagement in hookup culture was examined.

Method

Participants completed several surveys, which measured participants’ pornography consumption, personal religiosity, family sexual communication, and engagement in hookup culture. A path analysis model was used to analyze the relationship between the proposed variables.

Results

The path analysis model indicated that the initial model was a …

Islam, Christianity, Traditional Religions And Power Politics In Northern Nigeria Since Pre-Islamic Period, Emmanuel M. Abar

Dissertations

Problem

Currently in Northern Nigeria, religious interaction among the three major religious traditions, Islam, Christianity, and African Traditional Religion, is marred by violent religious conflicts. Also, competing concepts of religious legitimacy, which appeal to the historical heritage of Nigeria, are often used to validate and justify the violation of religious freedom. Does the current state of religious interaction among the various religious groups reflect the true heritage of religious interaction in Northern Nigeria? Or is it possible that the history of the interaction between African Traditional Religions, Islam, and Christianity in the past might actually be a heritage that points …

Ceramic Architectural Models From The Madaba Plains Region: A Selected Art Historical Analysis, Stefanie P. Elkins

Dissertations

Problem

Architectural models can be described as small, ceramic, house-shaped structures that come in an often bewildering array of shapes and sizes. They appear all over the ancient Near East, and although evidence shows that they were created as early as the Neolithic period, they seem to have peaked in popularity and proliferation during the Iron Age. A few studies and several typologies have been offered over the years, but none have addressed iconography or artistic motifs as well as shape. Furthermore, no in-depth typology of architectural models within the country of Jordan has been offered. This dissertation explores the …

Motivation For The Sharing Of Material Possessions In Acts, Philo's De Vita Contemplativa And The Didache: A Comparative Study, Lena V. Toews

Dissertations

Luke, in the book of Acts, depicts the sharing of possessions as a practice in the Jerusalem community of the first century. Several pericopes, occurring primarily in the first part of the book of Acts, embody the idea of shared property and seem to have important parallels to other sources of the time, including the Jewish author Philo’s work De vita contemplativa, where he describes a group he calls, “Therapeutae,” and in the Jewish Christian document Didache. This study seeks to identify beliefs correlated with the material sharing practices in the community of Acts and compare them with De vita …

The Third Space: The Meeting Of Jew And Christian In The Act Of Remembering, Restoring, And Reconciling - A Case Study Of The Matzevah Foundation, Steven D. Reece

Dissertations

Problem

Due to long-standing religious, racial, and cultural tensions, a complex and challenging relationship exists between Jews and Christians. The resulting breach isolates and separates these two faith groups from each other. Consequently, they struggle to interact and engage in meaningful dialogue, which could repair the breach and lead to forgiveness and reconciliation. Dialogue bridges the gap between Jew and Christian allowing them to meet in the third space—the liminal space of the Jewish cemetery in Poland. Jews and Christians may deal with the evil of the past through what researchers term as "loving acts."

Method

This study was conducted …

A Reassessment Of The Excavations At Tall Safut, Owen D. Chesnut

Dissertations

Problem

The site of Tall Safut in Jordan was excavated under the direction of Donald Wimmer during the years of 1982-2001. Other than the preliminary reports and encyclopedia articles published by Wimmer, no detailed analysis of the remains and no final reports have been published since the conclusion of excavations in 2001. The site has received only brief mention in other articles and books dealing with archaeology because of its remains dating to the Middle Bronze Age, Late Bronze Age, and Iron Age. However, there is a significant gap in the scholarly understanding of the history of the northern hill …