Engineering Commons^™

Optimization Of Wsu Total Ankle Replacement Systems, Bradley Jay Elliott

Browse all Theses and Dissertations

Total ankle arthroplasty (TAR) is performed in order to reduce the pain and loss of ambulation in patients with various forms of arthritis and trauma. Although replacement devices fail by a number of mechanisms, wear in the polyethylene liner constitutes one of the dominating failure modes. This leads to instability and loosening of the implant. Mechanisms that contribute to wear in the liners are high contact and subsurface stresses that break down the material over time. Therefore, it is important to understand the gait that generates these stresses. Methods to characterize and decrease wear in Ohio TARs have been performed …

Inventory Systems With Transshipments And Quantity Discounts, Gregory Daniel Noble

Browse all Theses and Dissertations

This research advances knowledge in the area of inventory systems and the relationship between competing retailers and suppliers of goods. This dissertation studies retailers that face uncertainty in the demand for goods and who purchase the goods from a single supplier. A game theoretic methodology is developed to analyze supplier pricing decisions and retailer quantity decisions and interactions in a competitive transshipment system where quantity discounts are offered. The system studied differs from previous work in the subject by introducing quantity discounts from supplier to retailer into a system of competitive retailers that transship stock. Analysis of these systems focuses …

Human Action Recognition By Principal Component Analysis Of Motion Curves, Daniel Stephen Chivers

Browse all Theses and Dissertations

Human action recognition is used to automatically detect and recognize actions per- formed by humans in a video. Applications include visual surveillance, human-computer interaction, and robot intelligence, to name a few. An example of a surveillance application is a system that monitors a large public area, such as an airport, for suspicious activity. In human-machine interaction, computers may be controlled by simple human actions. For example, the motion of an arm may instruct the computer to rotate a 3-D model that is being displayed. Human action recognition is also an important capability of intelligent robots that interact with humans.

General …

Computational Investigation Of Ethanol And Bifuel Feasibility In Solstice Engine, Adam Michael Blake

Browse all Theses and Dissertations

A Gasoline Direct Injection (GDI) engine enables an increased fuel efficiency and higher power output than a conventional Port Fuel Injection (PFI) system. By injecting pressurized fuel straight into each cylinder of an internal-combustion engine, the degree of fuel atomization is increased, as well as the fuel vaporization rate. In order to further harness the effects of direct injection, ethanol is implemented as a fuel. The cooling effect of ethanol fuel droplets changing to vapor inside the combustion chamber facilitates a higher compression ratio, thus increasing engine power and efficiency. Three dimensional computational simulation is used to investigate the feasibility …

Traffic Surveillance Using Low Cost Continuous Wave (Cw) Doppler Radars, Wu Yang

Browse all Theses and Dissertations

Low cost un-modulated continuous wave (CW) radar (CW Doppler radar) can be used to measure the speed of a vehicle. Traditionally, a radar gun, a lidar gun or a speed camera is used to capture a speeding vehicle. A radar gun can either measure the fastest vehicle or the vehicle with the strongest reflection. If a radar gun is used, a police officer must determine which vehicle has the speed shown on the screen of the radar gun. A lidar gun can precisely detect a speeding vehicle, but it requires precise aiming. When a camera is used, a picture will …

High-K Material Based Leaky-Wave Antenna Design, Implementation, And Manufacture, Jiahui Wang

Browse all Theses and Dissertations

Leaky-wave antennas are a class of antennas which apply a traveling wave on a guiding structure as the main radiation mechanism. The properties of leaky-wave antennas are light weight, easy to fabricate, and readily integrated into conventional millimeter-wave systems. These features make leaky-wave antennas attractive. The most important characteristic is that the antenna can steer the beam direction through changing the operating frequency rather than switching the antenna itself. Variety types of leaky-wave antennas have been introduced and developed during the past 70 years. However, there is no existing leaky-wave antenna which can widely steer the beam scanning angle by …

Regulation Of The Transcription And Subcellular Localization Of The Tumor Suppressor Pten By Δnp63Α, Mary Kathryn Leonard

Browse all Theses and Dissertations

Non-melanoma skin cancers (NMSCs) are the most common form of cancer in the United States with an estimated 3.5 million new cases each year. Surgical excision is the main treatment for NMSC, but leaves the potential for disfiguring scars and does not fully reduce the risk of recurrence since the surrounding tissue is also sun damaged and may contain tumor-promoting mutations. By understanding the molecular etiology of NMSC we may be able to expand treatment options to more than just resection. Normal epidermal development is dependent upon the expression of the transcription factor p63. Amplification of the ΔNp63α isoform is …

Uhf-Sar And Lidar Complementary Sensor Fusion For Unexploded Buried Munitions Detection, Randy S. Depoy Jr.

Browse all Theses and Dissertations

Given the UHF bands properties of foliage and round penetration, a UHF-SAR image contains both above- and below-surface scatterers. The problem of detecting sub-surface objects is problematic due to the presence of above-surface scatterers in the detection images. In case of a single-pass anomaly image or a two-pass change image, the resulting anomalies or changes are due to scatterers above and below the surface, where the above surface anomalies/changes act as confusers. LIDAR digital elevation models (DEM) provide georegistered information about the above-surface objects present in the UHF-SAR scene. Detection of the above-surface objects in the LIDAR domain is used …

Behavioral Signature-Based Framework For Identifying Unsatisfiable Variable Mappings Between Digital Designs, Vaibhav Uday Tendulkar

Browse all Theses and Dissertations

Throughout its design process (from specification to implementation) a digital circuit goes through a variety of structural changes. These changes are introduced primarily due to the use of automated tools in the design process. Checking whether the Boolean functions representing the two designs are equivalent is thus necessary to verify if a design implementation adheres to its specification. Combinational Equivalence Checking (CEC) - a process of determining whether two combinational design functions are equiv-alent, has been one of the most researched Boolean matching problems. The well-known CEC techniques that have been proposed adopt some kind of a formal approach such …

Measurement Of Static And Dynamic Performance Characteristics Of Electric Propulsion Systems, Aron Jon Brezina

Browse all Theses and Dissertations

Today's unmanned aerial vehicles are being utilized by numerous groups around the world for various missions. Most of the smaller vehicles that have been developed use commercially-off-the-shelf parts, and little information about the performance characteristics of the propulsion systems is available in the archival literature. In light of this, the aim of the present research was to determine the performance of various small-scale propellers in the 4.0 to 6.0 inch diameter range driven by an electric motor. An experimental test stand was designed and constructed in which the propeller/electric motor was mounted in a wind tunnel for both static and …

Nano-Scale Rf/Microwave Characterization Of Materials' Electromagnetic Properties, Joshua Allen Myers

Browse all Theses and Dissertations

There are two words that describe the direction of today's electronic technology, smaller and faster. With the ever decreeing size scientists and engineers must have a way to characterize materials in the nm range. In this thesis characterization of nano-materials is discussed based on scanning probe microscopy and an in-depth look at RF/microwave frequencies by scanning microwave microscopy. Recently, low-temperature spin-sprayed ferrite films (Fe3O4) with a high self-biased magnetic anisotropy field have been reported, showing FMR frequency>5 GHz. Such films hold great potential for RF/microwave devices and find immediate applications. In this study, we performed in situ scanning microwave …

Digital Wideband Spectral Sensing Receiver, Lawrence D. Burich

Browse all Theses and Dissertations

Detecting, channelizing, and characterizing radio frequency signals is a fundamental requirement for electronic warfare receivers as well as in commercial wireless applications where it is important to determine activity/inactivity in specified bands for spectral sharing and interference avoidance. Spectral sensing receivers are required to cover bandwidths in the GHz range and channelize signals into frequency bins in the kilo-hertz or mega-hertz range depending on the application. The difficulty is to detect, then determine spectral characteristics of multiple signals with varying power levels and signal characteristics in real time. A number of current Digital Wideband Spectral Sensing Receiver (DWSSR) architectures are …

Prediction Of Optimal Bayesian Classification Performance For Ladar Atr, Kristjan H. Greenewald

Browse all Theses and Dissertations

We consider the problem of LADAR ATR classifier performance prediction in the presence of arbitrary nuisance parameters including but not limited to pose. We use several noise models for both range images and point clouds that are significantly more accurate and complex than the Gaussian models used by previous non-Monte Carlo prediction methods. Two accurate new methods of efficiently predicting the optimum Bayesian classification performance are then derived, and applied to the noise models. Advantages of these methods include significant gains in accuracy for medium to high noise levels and the ability to handle target near symmetry. Extensions are developed …

'Omic' Evaluation Of The Region Specific Changes Induced By Non-Cholinergic Diisopropylfluorophosphate (Dfp) Exposure In Fischer 344 Rat Brain, Deirdre A. Mahle

Browse all Theses and Dissertations

Organophosphorous compounds (OPs) are a class of serine esterase inhibitors that have widespread application as pesticides, veterinary pharmaceuticals and chemical warfare agents. Environmental contamination is ubiquitous. The threat of exposure is a concern for both military and civilian populations. Acute inhibition of acetylcholinesterase by OPs triggers a cholinergic crisis that results in muscle flaccidity, paralysis, convulsions and death. At low doses OPs can alter neuronal differentiation, cell signaling, behavior and cognition through unknown mechanisms. An imbalance of reactive oxygen species may be implicated in the adverse effects of OPs. An integrated approach using both metabolomic and transcriptomic techniques was used …

An Evaluation Of Discharge Policies At A Generic Acute Care Hospital, Elizabeth A. Crawford

Browse all Theses and Dissertations

One of the main issues faced within the U.S. healthcare continuum is ineffective care transition. Ineffective transitions from one area of care to the next can lead to a reduction in quality of care, an increased risk of readmission, and an increase in healthcare costs. According to the National Transitions of Care Coalition (NTOCC), as many as 42% of the hospitals surveyed reported that care transitions during coordinated care delivery do not go as planned. One of the primary reasons for ineffective care transition is poor discharge planning. The purpose of this research is to analyze the effect of various …

Characterization, Stability, And Transport Through Defects In Graphene Nanoribbons, Sri Krishna Divya Pemmaraju

Browse all Theses and Dissertations

Graphene nanoribbons (GNRs) constitute a new class of nanostructured materials with unique properties and significant potential for applications. During production of GNRs, defects are generally introduced within the lattice. Assessment of defects' stability and characterization of their effects on GNRs are therefore very important for predicting GNRs performance under realistic circumstances. Here we consider various possible defects, namely the ones caused by removal/addition of carbon atoms from/to the lattice as well as those caused by bond rotation/rearrangement. Our study is based on ab initio geometry optimization and electronic structure calculations. We determine which defects can be stable in graphene nanoflakes …

Extension Of Polar Format Scene Size Limits To Squinted Geometries, Matthew Steven Horvath

Browse all Theses and Dissertations

The Polar Format Algorithm (PFA) is an often used algorithm to image synthetic aperture radar (SAR) phase history data. The algorithm relies on a far-field approximation wherein the curved wavefront of the transmitted pulses is approximated as a planar wavefront, introducing spatially variant phase errors in the phase history. While allowing for faster image formation compared to more exact imaging algorithms such as convolution backprojection, these phase errors lead to the distortion and defocus of point targets, degrading the quality of the resulting imaged scene.

Historically, a Taylor expansion has been used to approximate the phase errors leading to distortion …

A Unified Nonlinear Adaptive Approach For The Fault Diagnosis Of Aircraft Engines, Remus C. Avram

Browse all Theses and Dissertations

In this thesis, a fault detection and isolation (FDI) method is developed for aircraft engines by utilizing nonlinear adaptive estimation techniques. Engine sensor faults, actuator faults and component faults are considered under one unified framework. The fault diagnosis architecture consists of a bank of nonlinear adaptive estimators. One of them is the fault detection estimator used for fault detection, and the remaining ones are fault isolation estimators employed to determine the particular fault type/location after fault detection. Each isolation estimator is designed based on the functional structure of a particular fault type under consideration. The FDI architecture has been integrated …

Mapping Algorithm For Autonomous Navigation Of Lawn Mower Using Sick Laser, Shashidhar Baichbal

Browse all Theses and Dissertations

The objective of this thesis is to present a mapping algorithm for autonomous navigation of a lawnmower based on the range and bearing information of a SICK laser. The Simultaneous Localization and Mapping (SLAM) algorithm is a tool that can be used to navigate unmanned vehicle in an unknown environment. The two-dimensional (2D) maps of the obstacles can be obtained if the laser scans the environment in a plane horizontal to the ground. However, the 2D map does not give information of the objects that are placed below the height of the laser. This makes it difficult for the lawn …

The Demonstration Of Smse Based Cognitive Radio In Mobile Environment Via Software Defined Radio, Ruolin Zhou

Browse all Theses and Dissertations

With the emergence of increasing number of wireless devices and demands for higher data rates, spectrum crowding and congestion increases. Spectrum congestion problem has been challenging wireless communication engineers for a few decades. However, recent studies indicate that most of the time wide ranges of the radio spectrum are rarely utilized. Hence, the spectrum congestion is mainly due to the inefficient spectrum usage rather than the spectrum scarcity. To exploit under used spectrum and utilize the spectrum efficiently in dynamically changing environments, a new technology is needed. Cognitive Radio (CR) arises to be a possible solution to spectral crowding problem …

Key Factors Influencing The Structure And Electrochemical Performances Of Lifepo4 Via Sol-Gel Synthesis, Chuang Guan

Browse all Theses and Dissertations

Olivine structured LiFePO4 is a promising cathode material for the next generation of lithium ion batteries for its low cost, environmental benign, good cycling performance and safety, etc. However, its intrinsic poor electrical conductivity and diffusion capability of lithium ion greatly hinder its application in the high power recharge battery. In this research, a cost-effective sol-gel method was used to synthesize carbon coated LiFePO4 (LiFePO4/C) materials. The influences of the synthesis parameters, including the species of iron source, lithium content, chelating agents and carbon sources, PH value of the sol, and sintering conditions etc., on the structure and electrochemical properties …

The Role Of Amp-Activated Protein Kinase (Ampk) In Hypoxic Chemotransduction By The Carotid Body, Heidi Lynn Jordan

Browse all Theses and Dissertations

The carotid bodies are small sensory organs located along the bifurcation of the carotid arteries. They detect changes in blood gases and relay this information to the brain to allow for initiation of appropriate respiratory and cardiovascular responses. A decrease in oxygen (hypoxia) sensed by the carotid body results in an increase in firing of the carotid sinus nerve and ultimately a change in one's breathing pattern. An inability to respond to an acute hypoxic (low oxygen) episode via increased ventilation may result in death or lead to pathological or chronic conditions such as stroke and hypertension (Prabhakar et.al., 2005). …

Modeling And Simulation Of A Dynamic Turbofan Engine Using Matlab/Simulink, Scott Michael Eastbourn

Browse all Theses and Dissertations

A dynamic, high-bypass turbofan engine has been developed in the modeling and simulation environment of MATLAB/Simulink. Individual elements, including the fan, high pressure compressor, combustor, high pressure turbine, low pressure turbine, plenum volumes, and exit nozzle, have been combined to investigate the behavior of a typical turbofan engine throughout an aircraft mission. Special attention has been paid to the development of transient capabilities throughout the model, increasing model fidelity, eliminating algebraic constraints, and reducing simulation time through the use of advanced numerical solvers. This lessening of computation times is paramount for conducting future aircraft system-level design trade studies efficiently, as …

A Basic Understanding Of Rapid Mold Surface Heating Via Laser Energy, Charles Daniel Fox

Browse all Theses and Dissertations

As the research and development of surface heating methods have increased in the recent years, the consensus has been reached amongst the injection molding community that an elevated mold surface temperature near or greater than the polymer solidification temperature provides acceptable replication of the desired micro-structured parts. The laser heating experimental work and simulation development carried out includes two sample sizes similar to those used in injection molding. A 100W CO2 laser incident on three samples of different surface roughnesses has shown to have elevated temperatures via thermal cameral data and thermocouple measurements. Among five different laser spot sizes varying …

The Role Of Angiotensin Converting Enzyme (Ace) 2 In A Murine Model Of Insulin Resistance And Albuminuria, Nathan Michael Weir

Browse all Theses and Dissertations

Insulin resistance and kidney disease are intimately linked and both independently tied to dysregulation of the renin angiotensin system (RAS). The purpose of this research was to better investigate Angiotensin Converting Enzyme (ACE) 2 as a possible motif in the pathophysiology of these two disease processes. The project was divided into two parts. Part 1 investigated ACE2 KO mice as a model of albuminuria. Part 2 investigated how the lack of ACE2 enzyme affected glucose homeostasis and subsequent albuminuria.

Part 1: The Role of ACE2 in the Progression of Albuminuria. To determine if global loss of ACE2 leads to spontaneous …

Effect Of Cooling Rate And Mold Counter Pressure On The Crystallinity And Foaming Control In Microcellular Injection Molded Polypropylene Parts, Jeffrey Scott Cousineau

Browse all Theses and Dissertations

Microcellular polymer injection molding is a growing industry technique due to its ability to produce dimensionally stable stress free parts while reducing cycle time, material usage, and energy costs. The process was invented by Dr. Nam P. Suh at the Massachusetts Institute of Technology in the early 1980's. The basic idea is to dissolve a supercritical fluid into the polymer melt which will nucleate and expand within the part core after injection during the cooling stage. Microcellular polymer injection molding is becoming increasingly popular in automotive, semiconductor, and industrial applications. While the technique has been widely successful using amorphous polymers, …

Structural And Electronic Properties Of Two-Dimensional Silicene, Graphene, And Related Structures, Ruiping Zhou

Browse all Theses and Dissertations

Traditional CMOS (complementary metal-oxide-semiconductor) transistors have already been in the nanometer range. As bulk silicon material is approaching its physical limits, it is highly desirable to seek novel, functional materials to continue Moore's law. Two-dimensional(2D) materials, such as graphene and silicene, have attracted great attention since they were envisioned a few years ago, having extraordinary electrical properties. Research in this work was focused on understanding the structural and electronic properties of a few atomic layers of carbon (graphene) and silicon (silicene). Atomic structures of the 2D materials, corresponding band structures, and transport properties were calculated based on density functional theory. …

Isothermal Deformation And Modeling Of Ti-6al-4v, Vamsi Krishna Vempati

Browse all Theses and Dissertations

Ti-6Al-4V has attractive properties such as high strength to weight ratio, good fatigue properties and excellent corrosion resistance and these properties have made this alloy an important material for the aerospace industry. In this thesis, the deformation behavior of Ti-6Al-4V with several processing histories, was studied by conducting isothermal constant strain rate compression tests over a temperature range of 829°C to 996°C (1525°F to 1825°F) and at strain rates of 10-2 s-1, 10-1 s-1 and 100 s-1. True stress versus true strain flow curves showed a peak stress followed by flow softening. The data was analyzed to obtain constitutive equations …

Computational Investigation Of A Hinge-Connected Hovering Plate, Zachary Robert Gaston

Browse all Theses and Dissertations

A simplified conceptual flapping wing MAV design, capable of hover, is formed from the works of both biologists and engineers, studying the behavior of flying insects and the aerodynamics of flapping flight. With this new model, hovering hinged plates are used to study the effects of passive deflection on aerodynamic performance using two-dimensional Direct Numerical Simulations (DNS) at low Reynolds numbers (Re). The hinge is modeled as a torsional spring at the leading edge, where prescribed motion is applied. The influence of forced-to-natural frequency ratio (hinge stiffness) and stroke-to-chord ratio (leading edge kinematics) are studied, to explore the effects that …

Ultra Low Power Read-Out Integrated Circuit Design, Jian Chen

Browse all Theses and Dissertations

Carbon nanotubes (CNTs) are widely studied by the researchers in recent years, as they have small size, large strength, highly electrical and thermal conductivity. The single-walled CNT (SWNT) is readily changed in electrical resistance when exposed to gas, and has significant use in environmental monitoring, agriculture and fishing industry, chemical industry and even security. A read-out integrated circuit (ROIC) is required to detect the resistive change. In this thesis, an ultra-low power, wide dynamic detecting range and small size CMOS ROIC design is presented. This ROIC can interface wide dynamic range signal up to more than two orders (100pA-60nA) from …