Engineering Commons^™

Ultrasonic Nondestructive Evaluation Of Metal Additive Manufacturing., Venkata Karthik Nadimpalli

Electronic Theses and Dissertations

Metal Additive Manufacturing (AM) is increasingly being used to make functional components. One of the barriers for AM components to become mainstream is the difficulty to certify them. AM components can have widely different properties based on process parameters. Improving an AM processes requires an understanding of process-structure-property correlations, which can be gathered in-situ and post-process through nondestructive and destructive methods. In this study, two metal AM processes were studied, the first is Ultrasonic Additive Manufacturing (UAM) and the second is Laser Powder Bed Fusion (L-PBF). The typical problems with UAM components are inter-layer and inter-track defects. To improve the …

Horse Racing Prediction Using Graph-Based Features., Mehmet Akif Gulum

Electronic Theses and Dissertations

This thesis presents an applied horse racing prediction using graph based features on a set of horse races data. We used artificial neural network and logistic regression models to train then test to prediction without graph based features and with graph based features. This thesis can be explained in 4 main parts. Collect data from a horse racing website held from 2015 to 2017. Train data to using predictive models and make a prediction. Create a global directed graph of horses and extract graph-based features (Core Part) . Add graph based features to basic features and train to using same …

Vertical Gallium Nitride Schottky Diodes For Power Switching Applications., Sowmya Kolli

Electronic Theses and Dissertations

Gallium nitride (GaN) has enormous potential for use in devices operating at high power, frequency and temperature. Its wide band gap, high critical electric field and favourable carrier properties lead to lower switching losses and conduction losses in power electronic devices. However, most GaN rectifiers reported to date exhibit an ON-resistance (Ron) versus breakdown voltage much below theoretical predictions. Heteroepitaxial growth of GaN on substrates such as SiC, Si, and sapphire suffer from a high density of threading dislocations defects due to the mismatch in lattice constants and thermal expansion coefficients. Vertical devices, in which a bulk GaN substrate is …

Machine Learning For Omics Data Analysis., Ameni Trabelsi

Electronic Theses and Dissertations

In proteomics and metabolomics, to quantify the changes of abundance levels of biomolecules in a biological system, multiple sample analysis steps are involved. The steps include mass spectrum deconvolution and peak list alignment. Each analysis step introduces a certain degree of technical variation in the abundance levels (i.e. peak areas) of those molecules. Some analysis steps introduce technical variations that affect the peak areas of all molecules equally while others affect the peak areas of a subset of molecules with varying degrees. To correct these technical variations, some existing normalization methods simply scale the peak areas of all molecules detected …

Simulation-Based Analysis And Optimization Of The United States Army Performance Appraisal System., Lee A. Evans

Electronic Theses and Dissertations

In this dissertation, a discrete event simulation framework is considered to replicate the dynamics, structure, and regulatory constraints placed on the officers in the U.S. Army. Using performance appraisal data provided by the United States Army Human Resources Command, we create a multi-objective response function that quantifies the human behavior associated with evaluating subordinates. Utilizing simulation-optimization techniques for model validation enables estimating unknown input parameters, such as human behavior, based on historical data. Furthermore, the model allows users to analyze the effects of current constraints on the evaluation system and the effects of proposed personnel policy changes.The effectiveness of the …

Challenges In Flexible Microsystem Manufacturing : Fabrication, Robotic Assembly, Control, And Packaging., Danming Wei

Electronic Theses and Dissertations

Microsystems have been investigated with renewed interest for the last three decades because of the emerging development of microelectromechanical system (MEMS) technology and the advancement of nanotechnology. The applications of microrobots and distributed sensors have the potential to revolutionize micro and nano manufacturing and have other important health applications for drug delivery and minimal invasive surgery. A class of microrobots studied in this thesis, such as the Solid Articulated Four Axis Microrobot (sAFAM) are driven by MEMS actuators, transmissions, and end-effectors realized by 3-Dimensional MEMS assembly. Another class of microrobots studied here, like those competing in the annual IEEE Mobile …

A 3d Numerical Analysis Of The Railway To Compare The Performance Of The Granular And Asphalt Trackbeds., Thammapot Wattanapanalai

Electronic Theses and Dissertations

In the last two decades, trains have been developed either to carry heavy weight of cargo or for high-speed rail transport. Nonetheless, track structure, have not been improved adequate to support the extra loads or dynamic vibrations of high-speed trains. As a result, the performance of track will be affected from heavy freight or high-speed trains. In the long term it results in trackbed damage by increasing the subgrade and ballast displacement. Besides, it negatively affects the performance of the locomotives. Therefore, alternative subballast, should be introduced to reduce the stress and deformation of the track under dynamic or heavy …

Maintainability Analysis Of Mining Trucks With Data Analytics., Abdulgani Kahraman

Electronic Theses and Dissertations

The mining industry is one of the biggest industries in need of a large budget, and current changes in global economic challenges force the industry to reduce its production expenses. One of the biggest expenditures is maintenance. Thanks to the data mining techniques, available historical records of machines’ alarms and signals might be used to predict machine failures. This is crucial because repairing machines after failures is not as efficient as utilizing predictive maintenance. In this case study, the reasons for failures seem to be related to the order of signals or alarms, called events, which come from trucks. The …

Segmentation, Tracking, And Kinematics Of Lung Parenchyma And Lung Tumors From 4d Ct With Application To Radiation Treatment Planning., Jungwon Cha

Electronic Theses and Dissertations

This thesis is concerned with development of techniques for efficient computerized analysis of 4-D CT data. The goal is to have a highly automated approach to segmentation of the lung boundary and lung nodules inside the lung. The determination of exact lung tumor location over space and time by image segmentation is an essential step to track thoracic malignancies. Accurate image segmentation helps clinical experts examine the anatomy and structure and determine the disease progress. Since 4-D CT provides structural and anatomical information during tidal breathing, we use the same data to also measure mechanical properties related to deformation of …

End-To-End Learning Framework For Circular Rna Classification From Other Long Non-Coding Rnas Using Multi-Modal Deep Learning., Mohamed Chaabane

Electronic Theses and Dissertations

Over the past two decades, a circular form of RNA (circular RNA) produced from splicing mechanism has become the focus of scientific studies due to its major role as a microRNA (miR) ac tivity modulator and its association with various diseases including cancer. Therefore, the detection of circular RNAs is a vital operation for continued comprehension of their biogenesis and purpose. Prediction of circular RNA can be achieved by first distinguishing non-coding RNAs from protein coding gene transcripts, separating short and long non-coding RNAs (lncRNAs), and finally pre dicting circular RNAs from other lncRNAs. However, available tools to distinguish circular …

Assessment And Optimization Of Environmental Systems Using Data Analysis And Simulation., Milad Ebrahimi

Electronic Theses and Dissertations

For most environmental systems, specifically wastewater treatment plants and aquifers, a significant number of performance data variables are attained on a time series basis. Due to the interconnectedness of the variables, it is often difficult to assess over-arching trends and quantify temporal operational performance. The objective of this research study was to provide an effective means for comprehensive temporal evaluation of environmental systems. The proposed methodology used several multivariate data analyses and statistical techniques to present an assessment framework for the water quality monitoring programs as well as optimization of treatment plants and aquifer systems. The developed procedure considered the …

Robust Fuzzy Clustering For Multiple Instance Regression., Mohamed Trabelsi

Electronic Theses and Dissertations

Multiple instance regression (MIR) operates on a collection of bags, where each bag contains multiple instances sharing an identical real-valued label. Only few instances, called primary instances, contribute to the bag labels. The remaining instances are noise and outliers observations. The goal in MIR is to identify the primary instances within each bag and learn a regression model that can predict the label of a previously unseen bag. In this thesis, we introduce an algorithm that uses robust fuzzy clustering with an appropriate distance to learn multiple linear models from a noisy feature space simultaneously. We show that fuzzy memberships …

Longitudinal Tracking Of Physiological State With Electromyographic Signals., Robert Warren Stallard

Electronic Theses and Dissertations

Electrophysiological measurements have been used in recent history to classify instantaneous physiological configurations, e.g., hand gestures. This work investigates the feasibility of working with changes in physiological configurations over time (i.e., longitudinally) using a variety of algorithms from the machine learning domain. We demonstrate a high degree of classification accuracy for a binary classification problem derived from electromyography measurements before and after a 35-day bedrest. The problem difficulty is increased with a more dynamic experiment testing for changes in astronaut sensorimotor performance by taking electromyography and force plate measurements before, during, and after a jump from a small platform. A …

A Framework For Cardio-Pulmonary Resuscitation (Cpr) Scene Retrieval From Medical Simulation Videos Based On Object And Activity Detection., Anju Panicker Madhusoodhanan Sathik

Electronic Theses and Dissertations

In this thesis, we propose a framework to detect and retrieve CPR activity scenes from medical simulation videos. Medical simulation is a modern training method for medical students, where an emergency patient condition is simulated on human-like mannequins and the students act upon. These simulation sessions are recorded by the physician, for later debriefing. With the increasing number of simulation videos, automatic detection and retrieval of specific scenes became necessary. The proposed framework for CPR scene retrieval, would eliminate the conventional approach of using shot detection and frame segmentation techniques. Firstly, our work explores the application of Histogram of Oriented …

Network Science Algorithms For Mobile Networks., Heba Mohamed Elgazzar

Electronic Theses and Dissertations

Network Science is one of the important and emerging fields in computer science and engineering that focuses on the study and analysis of different types of networks. The goal of this dissertation is to design and develop network science algorithms that can be used to study and analyze mobile networks. This can provide essential information and knowledge that can help mobile networks service providers to enhance the quality of the mobile services. We focus in this dissertation on the design and analysis of different network science techniques that can be used to analyze the dynamics of mobile networks. These techniques …

Grid-Connected Photovoltaic Systems Based On Nonlinear Control., Pablo R. Rivera

Electronic Theses and Dissertations

Nowadays, due to the high-scale penetration of photovoltaic systems, reliable and efficient grid-connected photovoltaic (PV) systems utilizing the advances of power electronics and control system technology are desirable. Thus, single-stage grid-connected photovoltaic systems, have gained attention, especially in low voltage applications. However, PV systems exhibit nonlinear behavior that could negatively affect the performance of the system if they are not adequately compensated for. In this dissertation, using the general structure for the synchronous dq0 frame, a single-stage three-phase grid-connected photovoltaic system, and a single-stage single-phase grid-connected PV system, both with a nonlinear control strategy, are developed to track the maximum …

Multi Self-Adapting Particle Swarm Optimization Algorithm (Msapso)., Gerhard Koch

Electronic Theses and Dissertations

The performance and stability of the Particle Swarm Optimization algorithm depends on parameters that are typically tuned manually or adapted based on knowledge from empirical parameter studies. Such parameter selection is ineffectual when faced with a broad range of problem types, which often hinders the adoption of PSO to real world problems. This dissertation develops a dynamic self-optimization approach for the respective parameters (inertia weight, social and cognition). The effects of self-adaption for the optimal balance between superior performance (convergence) and the robustness (divergence) of the algorithm with regard to both simple and complex benchmark functions is investigated. This work …

Investigation Of Cardiovascular Tissue Following 56fe-Radiation And Potential Countermeasure Effectiveness., Alexandra R Decarlo

Electronic Theses and Dissertations

Exposure to ionizing radiation is an important medical concern because it can lead to health problems including cancer and cardiovascular issues. In space, astronauts are exposed to ionizing radiation that is not experienced by those who remain on Earth. This radiation can cause health problems such as cardiovascular disease. One way this can happen is through the creation of reactive oxygen species, which can activate TGF-β1, contributing to fibrosis or other cardiovascular problems. Antioxidants can be a potential pharmacological mitigator of these excess reactive oxygen species because of their ability to neutralize reactive oxygen species. One such antioxidant with potential …

Plga-Modified Nanoparticles For The Treatment Of Hypo-Vascularized Hpv-Related Cervical Cancers., Lee B. Sims

Electronic Theses and Dissertations

A major challenge associated with delivery of active agents in the female reproductive tract (FRT) is the ability of agents to efficiently diffuse through the cervicovaginal mucosa (CVM) and reach the underlying sub-epithelial immune cell layer and vasculature. A variety of drug delivery vehicles have been employed to improve the delivery of agents across the CVM and offer the capability to increase the longevity and retention of active agents to treat infections of the female reproductive tract. Nanoparticles (NPs) have been shown to improve retention, diffusion, and cell-specific targeting via specific surface modifications, relative to other delivery platforms. In particular, …

Phase Unwrapping Of 4d-Flow Mri Data With Graph Cuts., Andrew Justice

Electronic Theses and Dissertations

A common issue when measuring velocity utilizing 4D flow magnetic resonance imaging (MRI) is aliasing that occurs because of a low velocity encoding parameter (VENC). Aliasing can be avoided if the velocity encoding parameter is set above the largest velocity quantity. However, when this is done the velocity to noise ratio is lowered less detail is acquired in the image. Thusly, it is sometimes desirable to have a below the maximum velocity to acquire higher quality data.

Consequently, an efficient and robust algorithm is needed to unwrap the aliased data. This paper proposes an iterative graph cuts algorithm to perform …

Addition Of Exothermic Reaction Scale-Up Lab To Unit Operations Curriculum., Lisa A Anderson

Electronic Theses and Dissertations

According to the Chemical Safety Board’s 2002 report entitled "Improving Reactive Hazard Management,” the CSB identified 167 serious accidents involving uncontrolled chemical reactions in the United States between 1980 and 2001 causing 108 deaths and hundreds of millions of dollars in property damage. Of the 167 accidents, 35% involved runaway reactions. One noteworthy incident from recent history is the fatal explosion that occurred at T2 Laboratories in Jacksonville, FL as a result of improper scale-up and an insufficient cooling design for the system.

One recommendation resulting from the CSB investigation of the incident was that the Accreditation Board for Engineering …

A Novel Design For A Silicon And Cadmium Telluride Tandem Solar Cell., Jacob A Vittitow

Electronic Theses and Dissertations

No abstract provided.

Reactive Lamination Of Perovskite Solar Cells., Lyndie Burns

Electronic Theses and Dissertations

Due to the growing demand for energy internationally and the environmental impact of other conventional energy technologies, solar power has been a growing area in the energy landscape. Perovskite research has increased substantially because of the high power conversion efficiencies, up to 22%, with many recent advances in the use of these organic-inorganic hybrid perovskites for photovoltaic cells. However, to bring perovskite solar cells into the industrial world, the overall cost of the manufacturing of the solar cell must be improved to compete with other well-developed photovoltaic technologies. Here is presented an alternative perovskite deposition method for methylammonium lead halide …

Investigating The Likelihood Of Pediatric Femur Fracture Due To Falls Through Finite Element Analysis., Keyonna Mckinsey

Electronic Theses and Dissertations

Bone fracture is the second most common injury of child abuse. Studies have generally reported that femur fractures are more likely due to abuse than accidental causes in cases where the child is non-ambulatory. They have also found that household falls are commonly offered as the cause of injury in cases of abuse. In this study, a finite element (FE) pediatric femur model will be developed and used to evaluate likelihood of fracture in common household fall scenarios (bed falls and feet first falls). This will provide greater biomechanical evidence as to the likelihood of femur fracture due to common …

Enhancing Performance Of Ionic Liquid Property Prediction With Molecular Dynamics., Trisha H. Patel

Electronic Theses and Dissertations

Molecular dynamics have been used to predict thermodynamic and transport properties of eight room-temperature ionic liquids. Simulation parameters including box size and van der Waals cutoffs were varied. The density, heat capacity, and self-diffusion coefficients of the ionic liquids were computed and compared to experimental data and to previously published simulations. Predicted properties were generally close to their experimentally observed values. It was determined that the prediction of ionic liquid properties via molecular dynamics simulations could be accelerated several-fold by using less stringent integration parameters and smaller simulation sizes. The properties of density and heat capacity did not change significantly …

Comparing Stenotic Blood Flow In Three- And Two-Dimensional Arterial Renderings Using Computational Fluid Dynamics And Multiphase Mean Age Theory., Jacob S. Garza

Electronic Theses and Dissertations

Over one million invasive coronary angiography procedures are performed annually in patients who experience chest pain or are known to have coronary artery disease. The procedure is carried out to ascertain the degree of arterial blockage (stenosis) that hinders blood flow to the heart. A cardiologist performing the procedure determines the physiological degree of a stenosis by either visual estimation, which is routine practice, or by invasively measuring fractional flow reserve (FFR), which is the current gold standard that has been demonstrated to improve patient outcomes and temper the cost of healthcare. Nevertheless, FFR is performed in only 10–20% of …

Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., Jeremiah R. Bauer

Electronic Theses and Dissertations

This thesis is an examination of two material systems derived from polylactic acid (PLA) and polyethylene glycol (PEG). PLA is a polymer commonly sourced from renewable sources such as starches and sugars. It is a relatively strong, biodegradable polymer, making it ideal for use in the body. Even though it has a relative high strength, PLA is also brittle leading to the use of plasticizers to increase flexibility. One such plasticizer is PEG, which is a material that can exist at room temperature as either a thin liquid, or a hard waxy solid depending on the molecular weight. The first …

Sum Frequency Generation Spectroscopy Of Simulated Protein Secondary Structures., Andrew J. Adams

Electronic Theses and Dissertations

Sum frequency generation (SFG) spectroscopy is an experimental technique for differentiating between various conformations and orientations of interfacial proteins. Combining a theoretical framework for SFG with molecular dynamics (MD) simulations provides a powerful tool for studying systems containing interfacial proteins with applications in cell transport, biofilms, and fermentation processes. Roeters’ method was used to calculate theoretical SFG responses for a variety of individual α-helix and β-sheet peptide secondary structures simulated using MD. Results show how the shape and locations of SFG amide I responses change with differences in hydrogen bonding patterns, peptide orientations, and SFG polarization combinations. The data presented …

Design And Development Of A Multifunctional Surgical Device For Ground And Space-Based Surgical Applications., Brooke Elaine Barrow

Electronic Theses and Dissertations

With the possibility of longer ventures into space, NASA will face many new medical challenges. The ability to surgically treat trauma and other disorders in reduced gravity requires reliable wound access, containment, and visualization. In collaboration with Carnegie Mellon University, the University of Louisville is currently developing the AISS (Aqueous Immersion Surgical System) to increase efficiency and control of the operative field in space-based surgeries. Reliable wound access and containment is achieved by placing a transparent wound-isolation dome securely over the wound-site and pressurizing it with a saline solution. Leak-free trocars provide access ports for various surgical instruments. This system …

Tumor-Targeted Double Emulsions For Ultrasound-Triggered Delivery Of Molecular Therapeutics., Connor S Centner

Electronic Theses and Dissertations

Cancer is the second leading cause of death in the United States, with 1.74 million new cancer cases diagnosed and 610,000 cancer deaths expected in 2018 alone. Current treatments often result in negative systemic effects and ineffective treatment of the tumor. Drug delivery vehicles have been developed for more effective local delivery methods, but many drug delivery vehicles lack spatial and temporal control. Targeted double emulsions are a new class of drug delivery vehicles which present a promising option for a high payload and controlled delivery. The purpose of our project was to develop and characterize an aptamer-chelated double emulsion …