Digital Commons Network^™

The Evaluation And Analysis Of The Impact Of Variability On The Twelve Workstation Factory, Hernando Garrido

Theses and Dissertations - UTB/UTPA

Presently, there is theory and work examples about factory performance presented in the book ―Optimizing factory Performance‖ by James Ignizio, Ph.D. The theory explains how to determine performance using three fundamental equations by considering the impact and propagation of variability through a 12-Workstation Factory Model, and a number of its variations. The objective of developing a simulation model was to serve as a tool for instructors to illustrate the impact and propagation of variability in the manufacturing industry and to investigate phenomena (i.e., time to reach steady state, impact of variability) in the three dimensions of manufacturing. The validation of …

Analysis And Design Of An Anisotropic, Compliant Suspension Component, Samantha Jean Salinas

Theses and Dissertations - UTB/UTPA

A steering pad on a train is meant to reduce the force on the wheel while moving along a curve in the rail. A new steering pad was desired with properties tuned for a new suspension system design. An anisotropic, compliant pad was designed for a specific stiffness anisotropy, 20:1. Finite element analysis was performed on various models as a guide to designing a pin with the desired stiffness ratio. A design was chosen for a prototype made of thermoset polyurethane, a similar material to that currently used. Experiments were performed on the prototype pad model to determine vertical and …

Analog Signal Processing Elements For Energy-Constrained Platforms, Kyle Robert Mcmillan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Energy constrained processing poses a number of challenges that have resulted in tremendous innovations over the past decade. Shrinking supply voltages and limited clock speeds have placed an emphasis on processing efficiency over the raw throughput of a processor. One of the approaches to increase processing efficiency is to use parallel processing with slower, lower resolution processing elements. By utilizing this parallel approach, power consumption can be decreased while maintaining data throughput relative to other more power-hungry architectures.;This low resolution / parallel architecture has direct application in the analog as well as the digital domain. Indeed, research shows that as …

Ultrasonic Instrumentation Instruction In Dental Hygiene Programs In The United States, Sharon Lee Stemple Hinchman

Graduate Theses, Dissertations, and Problem Reports (ETD)

The purpose of this study is to determine the existence and extent of ultrasonic scaling instrumentation instruction in dental hygiene programs nationally. Currently, there is no research available defining a consensus of instruction for ultrasonic instrumentation in dental hygiene programs. An email survey was sent to all directors of dental hygiene programs in the United States (n=323). The response rate was 45%. No significant differences in methods or extent of instruction were found between associate and baccalaureate degree granting programs. Eighty-nine percent of programs introduce hand scaling prior to ultrasonic scaling instrumentation instruction. Students in 96% of the programs are …

Experimental Analysis Of The Post-Failure Behavior Of Coal And Rock Under Laboratory Compression Tests, Dachao Neil Nie

Graduate Theses, Dissertations, and Problem Reports (ETD)

A major aspect of coal mine design is the structural stability of the mine. For establishing structural stability, the strength of the strata is determined by recovering the cores. The strength is determined through various methods and one method in particular is the Uniaxial Compressive Strength of the rock, which is commonly adopted as the standard strength indicator. However, in-situ behavior by past researchers have shown that rock and coal show significant residual strength contrary to the failure path observed in a conventional compression tests. Researchers in past had used stiff system for generating the post failure behavior of the …

Modeling And Flight Testing Of Differential Thrust And Thrust Vectoring On A Small Uav, Zachary J. Merceruio

Graduate Theses, Dissertations, and Problem Reports (ETD)

The primary objectives of this research are to mathematically model the propulsion forces applied to the aircraft during nominal, differential thrust, and thrust vectored flight configurations, and verify this modeling through simulation and flight testing experiments. This thesis outlines the modeling process, simulator development, design, and implementation of a propulsion assisted control system for the WVU Flight Control Systems Lab (FCSL) research aircraft. Differential thrust and thrust vectoring introduce additional propulsive terms in the aircraft force equations that are not present when the thrust line passes through the center of gravity. These additional forces were modeled and incorporated into a …

Modeling Of Utility Distribution Feeder In Opendss With Steady State Impact Analysis Of Distributed Generation, Vaidyanath Ramachandran

Graduate Theses, Dissertations, and Problem Reports (ETD)

With the deregulation of the electric power industry and the advancement of new technologies, the attention of the utilities has been drawn towards adopting Distributed Generation (DG) into their existing infrastructure. The deployment of DG brings ample technological and environmental benefits to the traditional distribution networks. The appropriate sizing and placement of DGs which generate power locally to fulfill consumer demands, helps to reduce power losses and avoid transmission and distribution system expansion.;The primary objective of this thesis is to model a utility distribution feeder in OpenDSS. Studies are conducted on the data obtained from American Electric Power utility. This …

Anisotropic Particles: Preparation And Study, Shengrong Ye

Graduate Theses, Dissertations, and Problem Reports (ETD)

Anisotropic particles have received significant attention in self-assembly for the large scale fabrication of hierarchical structures. Janus particles, a specific class of anisotropic particles, have two hemispheres with different materials. Due to the anisotropic nature of the particle shape and interactions, Janus particles have demonstrated interesting properties in interfacial assembly, switchable devices, cargo transport, and optical sensing. The objective of this research is to fabricate novel anisotropic Janus particles and explore their potential unique properties.;One of the driving forces arises from the previous work of bimetallic nanorods and their autonomous motion. The bimetallic nanorod systems undergo chemically powered non- Brownian …

Iris Recognition: Robust Processing, Synthesis, Performance Evaluation And Applications, Jinyu Zuo

Graduate Theses, Dissertations, and Problem Reports (ETD)

The popularity of iris biometric has grown considerably over the past few years. It has resulted in the development of a large number of new iris processing and encoding algorithms. In this dissertation, we will discuss the following aspects of the iris recognition problem: iris image acquisition, iris quality, iris segmentation, iris encoding, performance enhancement and two novel applications.;The specific claimed novelties of this dissertation include: (1) a method to generate a large scale realistic database of iris images; (2) a crosspectral iris matching method for comparison of images in color range against images in Near-Infrared (NIR) range; (3) a …

Modeling Studies To Evaluate Performance Of The Horizontal Wells Completed In Shale, Abbas Belyadi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The results of the modeling studies to determine the production performance of multiple fractured horizontal wells completed in shale formation has been summarized in this dissertation. A commercial reservoir simulator was utilized to model both single and dual porosity reservoir (with and without adsorption) with multiple layers. The impact of reservoir characteristics including natural fractures and hydraulic fractures properties on the production performance were investigated. In addition, the results were utilized to investigate the flow regimes for horizontal wells with one or multiple hydraulic fractures.;Flow regime identification in low permeability reservoirs is extremely critical to evaluate performance of the horizontal …

Modeling And Analysis Of Multiple Engine Aircraft Configurations For Fault Tolerant Control, Frederick M. Beamer

Graduate Theses, Dissertations, and Problem Reports (ETD)

A formal framework is presented that allows for the analysis of the potential for using engine thrust control for aircraft actuator failure accommodation. Three sets of parameters have been identified as critical: number of engines and their position, engine thrust and throttle dynamics, and type and severity of the actuator failure. A mathematical model was developed that allows for the determination of the values of some of the parameters when the others are imposed such as determining the thrust control authority when the engine locations and Euler angles are known. Additionally, the engine locations can be determined when the thrust …

Creating Reporter Systems Within Drosophila Melanogaster, Ashley Elizabeth Banks

Graduate Theses, Dissertations, and Problem Reports (ETD)

The objective of these projects was to generate two fluorescently based systems within Drosophila melanogaster for the advancement of molecular research. The first project was aimed to create fluorescent phosphomimetic constructs of m8, a regulator in eye formation. The second project was to create a fluorescent visual marker for heterochromatic gene silencing in Drosophila. Proper formation of the eye requires that only one cell from a group of equipotent cells assumes a neural fate (the R8 cell). The cells surrounding the R8 cell are prevented from assuming this outcome through a process known as lateral inhibition. Lateral inhibition uses the …

Gis Assisted Problem Analysis Of Trail Erosion In Monongahela National Forest, Steven J. Storck

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research investigates the frequency and patterns of trail erosion on purposefully selected natural surface trails in Monongahela National Forest. Trail erosion is considered a non-self-limiting process which degrades trail beds making them unattractive, difficult to travel on, and has the potential to impact local streams with the introduction of silt. Recreation ecology research delineates factors which influence the rate of erosion on a trail into three broad categories: recreational use, environmental conditions, and managerial actions. This study tests the relationship of variables from each of these categories to the local patterns of erosion. Three sampling strategies are used to …

Preclinical Pharmacology Of The Mdm2 Antagonist Nutlin-3a, Fan Zhang

Theses and Dissertations (ETD)

Nutlin-3a is an MDM2-p53 interaction antagonist that is under investigation in preclinical models for a variety of pediatric malignancies, including neuroblastoma, retinoblastoma, leukemia, and rhabdomyosarcoma. In the current research, we conducted preclinical pharmacology studies of nutlin-3a to evaluate the synergistic effect of the nutlin-3a and topotecan combination on neuroblastoma cell growth, to assess the effect of nutlin-3a on breast cancer resistance protein (BCRP), and to characterize the disposition of nutlin-3a in the mouse plasma and multiple tissues.

Activating the p53 pathway might offer a new therapy for neuroblastoma. In the first part of the study, we assessed the effect of …

Workplace Harassment: The Social Costs Of Bullying, Andra Gumbus, Bridget M. Lyons

WCBT Faculty Publications

Most research on workplace bullying uses survey results to understand working conditions, target and bully characteristics, and results of bullying situations. This study uses content analysis to determine themes emerging from a writing assignment that asks students to respond to questions about workplace bullying. The intent of the research is to enable bullying targets to better understand the situation, to help managers to learn how to mitigate possible bullying situations, and to assist witnesses to better react to workplace incidents.

A Network Based Theory Of Foreign Market Entry Mode And Post-Entry Performance, Jing'an Tang, Ben S. Liu

WCBT Faculty Publications

Foreign market entry through equity investment has been extensively studied and various theoretical lenses have been used. Most previous research also focuses attention on either the entry mode selection decision or the topic of post-entry performance, but rarely both. We build on existing research by developing a model of foreign market entry and post-entry performance that uses network theory and organizational ecology to provide a fuller explanation of this complex and critical multinational enterprise strategic behaviour. Four pairs of total eight propositions were developed and justified based on extent literature and sound logical reasoning. By focusing on both entry mode …

Sensitivity Of Seismic Response Of A 12 Story Reinforced Concrete Building To Varying Material Properties, Colin Leung

Master's Theses

The main objective of this investigation is to examine how various material properties, governed by code specification, affect the seismic response of a twelve- story reinforced concrete building. This study incorporates the pushover and response history analysis to examine how varying steel yield strength (Fy), 28 day nominal compressive concrete strength (f’c), modes, and ground motions may affect the base shear capacity and displacements of a reinforced concrete structure.

Different steel and concrete strengths were found to have minimal impact on the initial stiffness of the structure. However, during the post-yielding phase, higher steel and concrete compressive strengths resulted in …

Cubesat Constellation Analysis For Data Relaying, Bradley Ryan Smalarz

Master's Theses

Current CubeSat communication technology limits the amount of time, and number of accesses with ground stations. It has been proposed to use a constellation of CubeSats to improve relay performance and increase the number of accesses between a CubeSat and ground stations. By using the spatial and temporal analysis features of STK, coupled with the STK/Matlab interface a robust tool was created to analyze the performance of CubeSat constellations based on a store-and-forward communications model which is not currently supported by the STK Engine. Utilizing the Connect messaging format through a socket connection on the local machine, a Matlab graphical …

Seasonal And Anatomical Variation In Compact Bone Remodeling In The Adult Sheep, Joseph Calcagno

Master's Theses

ABSTRACT

SEASONAL AND ANATOMICAL VARIATION IN COMPACT BONE REMODELING IN THE ADULT SHEEP

Joseph Calcagno

In order to determine whether ovine compact bone is suitable for study of osteoporosis, the remodeling parameters of the untreated animal must be fully characterized. Ovine compact bone is an attractive large animal model due to its similarities in size and bone remodeling to humans. However hormonal, exercise, and dietary changes due to seasonal changes can cause treatment effects to be hidden or superimposed on existing changes in the bone. In order to determine if any seasonal or anatomical variation occurred in the compact bone …

Dimensional Stability Of Geosynthetic Clay Liners In Landfill Applications, Gregory R. Olsen

Master's Theses

An investigation was conducted related to the dimensional stability of geosynthetic clay liners (GCLs) in landfill applications. Multiple occurrences of panel separation of overlap seams in GCLs have been documented; however, explanation for the relative contribution of various mechanisms causing shrinkage has been limited. A systematic test program was conducted to determine the effects of a variety of conditions on GCL dimensional stability.

Effects of initial moisture content, permeant type, and overburden pressure were tested by subjecting various GCL products to wet-dry cycles and measuring the dimensional change with each cycle. Different GCL types were each tested under various combinations …

Analysis Of Contrast Enhancement Methods For Infrared Images, Sprinkle Christian

Master's Theses

Contrast enhancement techniques are used widely to improve the visual quality of images. The difference in luminance reflected from two adjacent surfaces creates contrast between the surfaces in the image. The greater the contrast, the easier it is to recognize and differentiate objects in an image. Thus object contrast is an important factor in the perception of the visual quality of an image and in its usefulness for object recognition and image analysis applications.

The focus of this thesis is on studying how well different contrast enhancement techniques developed for visible spectrum photographic images work on infrared images; to determine …

Modeling And Analysis Of A Four-Switch Buck-Boost Dynamic Capacitor, Oscar Plasencia

Master's Theses

Modern electric power utilities are facing a variety of challenges introduced by the increasing complexity of their operation, structure, and consumer loads. One such challenge has been to supply the ever growing demand for reactive power which is essential for grid support. For this reason dynamic VAR technologies are becoming much more important to modern day power systems. A recent dynamic VAR technology known as the Dynamic Capacitor offers full quadrant capacitive VAR control through the combination of AC/AC buck and boost cells. This paper introduces a new topology deemed the “Four-Switch Buck-Boost Dynamic Capacitor” which promises to combine the …

State Estimation For Tracking Of Tagged Sharks With An Auv, Christina Forney

Master's Theses

Presented is a method for estimating the planar position, velocity, and orientation states of a tagged shark. The method is designed for implementation on an Autonomous Underwater Vehicle (AUV) equipped with a stereo-hydrophone and receiver system that detects acoustic signals transmitted by a tag. The particular hydrophone system used here provides a measurement of relative bearing angle to the tag, but does not provide the sign (+ or -) of the bearing angle. A particle filter was used for fusing measurements over time to produce a state estimate of the tag location. The particle filter combined with an active control …

Comet: Constrained Optimization Of Multiple-Dimensions For Efficient Trajectories, Michael Curt Conrad

Master's Theses

The paper describes the background and concepts behind a master’s thesis platform known as COMET (Constrained Optimization of Multiple-dimensions for Efficient Trajectories) created for mission designers to determine and evaluate suitable interplanetary trajectories. This includes an examination of the improvements to the global optimization algorithm, Differential Evolution, through a cascading search space pruning method and decomposition of optimization parameters. Results are compared to those produced by the European Space Agency’s Advanced Concept Team’s Multiple Gravity Assist Program. It was found that while discrepancies in the calculation of ΔV’s for flyby maneuvers exist between the two programs, COMET showed a noticeable …

Madonna Inn: A Hotel In Context, Galadriel Bree Highhouse

Master's Theses

This paper examines the political, economic and social influences that contributed to the development of the Madonna Inn in San Luis Obispo. I provide a brief history of the hotel industry and place the Madonna Inn within the historiography and argue that the nexus of three elements in the 1950s and 1960s led to the growth and popularity of the Madonna Inn: fear of nuclear war, growth of the middle class, and the rise of automobile culture in America.

Developing Dendrifrom Facades Using Flow Nets As A Design Aid, Jonas H. Houston

Master's Theses

This thesis highlights a method of arriving at form that minimizes the need for high end technology and complex mathematical models, yet has structural principles of load flow at the highlighted methods core. Similar to how graphical statics assisted earlier architects and engineers to arrive at form by relating form and forces, this thesis suggests a method of form finding that relates the flow of stresses within solid masses to possible load-bearing façades. Looking to nature, where an abundance of efficient structural solutions can be found, this thesis focuses on a tree-like structural form called the dendriform. In doing so, …

Enhancement Of Light Absorption Efficiency Of Solar Cell Using Dual, Ashton Ellaboudy

Master's Theses

In this research we study the effect of adding a single diffraction grating on top of a solar cell. We simulated the square diffraction grating, as well as triangular diffraction grating. The single square grating showed more favorable results, achieved 330% power improvement compared to 270% power improvement in the single triangular grating case.

We simulated a triangle/triangle (top-bottom) and triangular/rectangular (top-bottom) grating cases. The Triangular grating achieved higher light absorption compared to rectangular grating. The best top grating was around 200nm grating period. We realized solar cell efficiency improvement about 42.4% for the triangular rectangular (top-bottom) grating.

We studied …

The Relationship Between Attitude And Anxiety Toward Teaching Science In Pre-Service Elementary Teachers And The Use Of Science Olympiad Events, Allison Armstrong Downing

Dissertations

The purpose of this study was to examine the relationship between the anxiety and attitudes of pre-service elementary teachers toward teaching science and the use of Science Olympiad events in an elementary science methods course. The participants were 34 pre-service elementary teachers enrolled in the Winter 2010 and Spring 2011 trimesters in the course Science in the Elementary School at a private university in south Mississippi. Attitude toward teaching science was measured using the Revised Science Attitude Scale. Anxiety was measured using the State-Trait Anxiety Inventory (Form Y). Data collection involved participants taking pretests for attitude and state anxiety on …

Investments In Leadership And Management Succession Planning At A Department Of Defense Organization In The Southeastern United States: A Review Of Strategic Implications, Richard Allen Jeffries

Dissertations

With the impending aging workforce retirement tidal wave, targeted investments are needed in leadership and management skills for new leader growth. Some organizations currently invest in leadership and management skill development. However, the impacts of the investments remain unknown in the organizations. A Department of Defense Organization in the Southeast United States (DODSE) serves as a scientific knowledge generating organization that supports the Department of Defense. At the DODSE, investments in leadership and management skills training began in 2007 with little understanding of how an increased investment in leadership and management training would be utilized within the organization. To create …

Is There A Relationship Between Electronic White Boards In The Classroom And Student Success?, John Joseph Mundy

Dissertations

The purpose of this study was to determine the effect of interactive electronic white boards, an advanced technology, on the academic performance of kindergarten through fifth grade elementary students. The participants represent seven local school districts with approximately 700 teachers instructing 16,421 students. The research gathered data from the teachers through a questionnaire designed by the researcher. Student data was also gathered as well as perceptions of trainers, teachers and administrators.

The study was designed to examine the independent variables and the impact or effect it has on students’ achievement in a Kindergarten through fifth grade elementary classroom. The independent …