Engineering Commons^™

Embedded System Design Of Robot Control Architectures For Unmanned Agricultural Ground Vehicles, Ryan Humphrey

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Engineering technology has matured to the extent where accompanying methods for unmanned field management is now becoming a technologically achievable and economically viable solution to agricultural tasks that have been traditionally performed by humans or human operated machines. Additionally, the rapidly increasing world population and the daunting burden it places on farmers in regards to the food production and crop yield demands, only makes such advancements in the agriculture industry all the more imperative. Consequently, the sector is beginning to observe a noticeable shift, where there exist a number of scalable infrastructural changes that are in the process of slowly …

Distributed Edge Bundling For Large Graphs, Yves Tuyishime

School of Computing: Dissertations, Theses, and Student Research

Graphs or networks are widely used to depict the relationships between data entities in diverse scientific and engineering applications. A direct visualization (such as node-link diagram) of a graph with a large number of nodes and edges often incurs visual clutter. To address this issue, researchers have developed edge bundling algorithms that visually merge similar edges into curved bundles and can effectively reveal high-level edge patterns with reduced visual clutter. Although the existing edge bundling algorithms achieve appealing results, they are mostly designed for a single machine, and thereby the size of a graph they can handle is limited by …

Exploring Eye Tracking Data On Source Code Via Dual Space Analysis, Li Zhang

School of Computing: Dissertations, Theses, and Student Research

Eye tracking is a frequently used technique to collect data capturing users' strategies and behaviors in processing information. Understanding how programmers navigate through a large number of classes and methods to find bugs is important to educators and practitioners in software engineering. However, the eye tracking data collected on realistic codebases is massive compared to traditional eye tracking data on one static page. The same content may appear in different areas on the screen with users scrolling in an Integrated Development Environment (IDE). Hierarchically structured content and fluid method position compose the two major challenges for visualization. We present a …

Modeling Climate Driven Urban Migration In The United States, Julia Beckwith

REU Final Reports

Though research on climate driven migration has become more prevalent, the majority of recent studies model migration patterns in the Global South. While these inquiries are rightfully focused on populations that will be disproportionately affected by climate change, countries in the Global North are not impervious to these effects. As global population distributions shift, it will be necessary to know which urban areas in the United States might be best equipped to handle influxes of people. Drawing on existing climate-migration frameworks, the agent-based model detailed in this paper utilizes available demographic and climate data to simulate climate-driven migration between key …

Bioengineering Extracellular Matrix Scaffolds For Volumetric Muscle Loss, Kevin Roberts

Graduate Theses and Dissertations

Volumetric muscle loss overwhelms skeletal muscle’s ordinarily capable regenerative machinery, resulting in fibrosis and severe functional deficits which have defied clinical repair strategies. My work spans the design and preclinical evaluation of implants intended to drive the cell community of injured muscle toward a regenerative state, as well as the development of an understanding of the molecular responses of this cell community to biomaterial interventions. I demonstrate a new class of biomaterial by leveraging the productive capacity of sacrificial hollow fiber membrane cell culture; I show specifically that unique threads of whole extracellular matrix can be isolated by solvent degradation …

Visualizing Ischemic Skin Flap Necrosis Through Phasor Analysis Of Autofluorescence Lifetime Images, Hallie Ramser Toomer

Graduate Theses and Dissertations

Necrotic skin flaps are difficult to predict and treat due to the lack of quantitative biomarkers. Label-free multiphoton microscopy is well suited for non-invasively monitoring skin metabolism through NAD(P)H and other intrinsic fluorophores, and offers immediate future directions for assessing necrosis in the clinic. The objective of this study was to assess whether phasor FLIM could be used to evaluate skin flap status and treatment efficacy in ex vivo skin sections. Phasor maps revealed differences in growth factor treatment and region, but changes in skin flap autofluorescence at 755nm excitation and 460nm emission were not just related to NAD(P)H. A …

Switching Trajectory Control For High Voltage Silicon Carbide Power Devices With Novel Active Gate Drivers, Shuang Zhao

Graduate Theses and Dissertations

The penetration of silicon carbide (SiC) semiconductor devices is increasing in the power industry due to their lower parasitics, higher blocking voltage, and higher thermal conductivity over their silicon (Si) counterparts. Applications of high voltage SiC power devices, generally 10 kV or higher, can significantly reduce the amount of the cascaded levels of converters in the distributed system, simplify the system by reducing the number of the semiconductor devices, and increase the system reliability.

However, the gate drivers for high voltage SiC devices are not available on the market. Also, the characteristics of the third generation 10 kV SiC MOSFETs …

Engineered Carbon-Nanocatalyst Composites And Carbon Mixed ‎Matrix Membranes ‎For Water And Wastewater Treatment ‎, Mojtaba Abolhassani

Graduate Theses and Dissertations

Carbonaceous materials such as graphene oxide, and activated ‎carbon have a wide range of ‎applications in water and wastewater treatment due to the high surface ‎area, unique structure, ‎and chemical and thermal stability. Carbon-based materials can be used as a ‎membrane, an ‎adsorbent, a support for nanomaterials, or ‎as a filler within membranes to remove contaminants ‎from water. In this research, the specific carbon materials and how their properties influence their ‎use and performance in ‎specific engineering applications is explored. ‎

Here, membrane filtration and adsorption/degradation of the water and wastewater using carbon-‎based material are investigated. The research firstly focuses …

Cognitive Satellite Communications And Representation Learning For Streaming And Complex Graphs., Wenqi Liu

Electronic Theses and Dissertations

This dissertation includes two topics. The first topic studies a promising dynamic spectrum access algorithm (DSA) that improves the throughput of satellite communication (SATCOM) under the uncertainty. The other topic investigates distributed representation learning for streaming and complex networks. DSA allows a secondary user to access the spectrum that are not occupied by primary users. However, uncertainty in SATCOM causes more spectrum sensing errors. In this dissertation, the uncertainty has been addressed by formulating a DSA decision-making process as a Partially Observable Markov Decision Process (POMDP) model to optimally determine which channels to sense and access. Large-scale networks have attracted …

Investigation Of The Biosynthetic Process Of Indigoidine, Yi Chen

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Indigoidine is a natural blue dye with antioxidant and antimicrobial activities. It has also been used as an indicator for gene expression based on its distinctive blue color. Similar to the industry blue dye indigo, indigoidine has a promising potential to be applied in industry as a blue dye. However, the indigoidine production level in the original microorganisms was very low. Heterologous expression of the responsible synthetase gene in Escherichia coli can facilitate the fast and large-scale production of indigoidine. Also, a good understating of the working mechanism of the synthetase is favorable for the industrial application.

In our previous …

Electrostatically Actuated Double Wall Carbon Nanotubes To Include Intertube Van Der Waals Forces, Ezequiel Juarez Ocanas

Theses and Dissertations

This work deals with the amplitude-frequency and amplitude-voltage responses of parametric and primary resonances of electrostatically actuated double-walled carbon nanotubes (DWCNTs). Nonlinear forces acting on the DWCNT are intertube van der Waals and electrostatic forces. Soft AC excitation and small viscous damping are assumed. In coaxial vibration, the outer and inner carbon nanotubes move together (in-phase), maintaining their geometric concentricity; while in noncoaxial vibration, the CNTs move in opposite direction (out-of-phase). Modal coordinate transformation is formulated. The Harmonic Balance Method (HBM) is used to find the free response solutions of the DWCNT. The Reduced Order Model (ROM) method is also …

Parametric Study Of Selective Laser Alloying Of Elemental Titanium And Boron Powders Using An Automated Deposition Mechanism, Julian V. Gonzalez

Theses and Dissertations

An automatic powder deposition and leveling mechanism was designed and constructed to assist in surface roughness experiments for titanium-boron samples. Previously developed energy models and x-ray diffraction analysis was used to confirm the creation of titanium diboride samples. To study TiB2 at different energy values, a 52 (2 factors, 5 levels) factorial design was used and carried out under an argon atmosphere, through the AM250 laser melting system. Two experimental runs were carried out and a total of 50 samples were assigned a surface roughness measurement through the Dektak XT profilometer. Graphically and with statistical analysis, the data was determined …

Optimal Control Strategies For Complex Biological Systems, Afroza Shirin

Mechanical Engineering ETDs

To better understand and to improve therapies for complex diseases such as cancer or diabetes, it is not sufficient to identify and characterize the interactions between molecules and pathways in complex biological systems, such as cells, tissues, and the human body. It also is necessary to characterize the response of a biological system to externally supplied agents (e.g., drugs, insulin), including a proper scheduling of these drugs, and drug combinations in multi drugs therapies. This obviously becomes important in applications which involve control of physiological processes, such as controlling the number of autophagosome vesicles in a cell, or regulating the …

A Methodology To Measure The Impact Of Diversity On Cybersecurity Team Effectiveness, Caralea May Cornel

Theses and Dissertations

In recent years, the definition of cybersecurity professional has been diluted to include more individuals, particularly women, to be included. Depending on the definition used, women currently comprise between 11% and 25% of the cybersecurity workforce. While multiple studies have indicated the benefits to diverse teams, research in the cybersecurity area is lacking.This research proposes a framework that uses a modified escape-the-room gamified scenario to measure the effectiveness of cybersecurity teams in technical problem-solving. The framework presents two routes, incident response and penetration testing, the participants can choose. In a preliminary study, this framework is used to show the combination …

Simulation Framework And Potential Field Relocation For Systems Of Shared Autonomous Vehicles, Landon Blaine Wright

Theses and Dissertations

Shared autonomous vehicles present a significant opportunity to change the way that urban mobility is viewed by society. By providing a shared mobility platform at a cost lower than has previously been obtainable there are significant possibilites to enable a new era of mobility for consumers. This opportunity, however, comes with significant risks in the form of emissions and increased road usage. Understanding how the risks and benefits of shared autonomous vehicles can be balanced is crucial to be able to adequately prepare for their introduction. One of the primary ways to understand the interplay between the risks and benefits …

Characterization Of Dislocation - Grain Boundary Interactions Through Electron Backscatter Diffraction, Landon Thomas Hansen

Theses and Dissertations

Further understanding of dislocation-GB interactions is critical to increasing the performance of polycrystalline metals. The research contained within this dissertation aims to further dislocation-GB interaction understanding through three research studies. First, the effect of noise in EBSPs on GND calculations was evaluated in order to improve dislocation characterization via HR-EBSD. Second, the evolution of GNDs and their effects on back stress was studied through experimental and computational methods applied to tantalum oligo specimens. Third, statistical analysis was used to evaluate grain parameters and current GB transmission parameters on their correlation with dislocation accumulation.

Distribution Of Tremorogenic Activity Among The Majorsuperficial Muscles Of The Upper Limb Insubjects With Essential Tremor, David Jordan Standring

Theses and Dissertations

Optimized peripheral tremor suppression could address many limitations of surgical or medicinal treatments of Essential Tremor, however it is not well understood how the tremorogenic activity is distributed among the muscles of the upper limb, and therefore how to optimize such suppression. We recorded electromyographic (EMG) activity in the 15 major superficial muscles from the shoulder to the wrist while subjects performed postural and kinetic tasks similar to activities of daily living. We calculated the power spectral density and computed the total power in the tremor band (4"12 Hz) for each muscle, from which we determined the distribution of tremorogenic …

The Effect Of Subglottic Stenosis On The Aerodynamic, Acoustical, And Vibratory Output Of Synthetic Vocal Fold Models, Benjamin Allen Hilton

Theses and Dissertations

There are many conditions and diseases that affect voice production. One of these, subglottic stenosis (SGS), is characterized by a narrowing of the trachea near the cricotracheal junction. SGS causes dyspnea (labored breathing) and frequently surgery is necessary to eliminate the airway obstruction. SGS is also believed to adversely affect voice quality. While significant research has been conducted to study the effect of SGS on breathing, relatively few studies concerning its effect on voice production have been performed. The purpose of this research was to provide quantitative results concerning the predicted effects of SGS on vocal fold (VF) vibration and …

Comparison Of Heat Generation Models In Finite Element Analysis Of Friction Welding, Richard Verile Livingston

Theses and Dissertations

Finite element models of friction welding can be used to estimate internal conditions of welds which are useful for weld analysis and developing experimental welding procedures. Many modeling techniques are used to accomplish these goals, each with relative strengths and weaknesses. A comparative analysis of friction welding models using different heat generation methods is presented. The three different heat generation methods examined were viscoplastic friction, constant steady-state generation, and experimentally measured power data. The models were compared against each other using three output measurements: temperature, axial force, and upset. The friction model predicted temperatures within 40 degrees C. Temperature accuracy …

Significance Of The Rates Of Atmospheric Deposition Around Utah Lake And Phosphorus-Fractionation Of Local Soils, Joshua Glen Reidhead

Theses and Dissertations

Eutrophic Utah Lake receives a large nutrient load from a variety of sources, includingtreated wastewater discharges, runoff and tributaries, recycling from bottom sediments andAtmospheric Deposition (AD). AD was the focus of this study and was comprised of twocomplementary parts. First was a study of nitrogen and phosphorus depositions from theatmosphere, and second was a study of phosphorous as contained in soils near Utah Lake viafractionation methods.The soil samples were found to contain approximately 1,000 mg-P/kg soil for totalphosphorus (TP). A separate phosphorus (P) fractionation gave slightly higher values, excludingthe residual P, we are 95% confident that one gram of sample …

Developing High Performance Magnesium Phosphate Cement Composite Bipolar Plates For Fuel Cells, Wenbin Hao, Hongyan Ma, Guoxing Sun, Zongjin Li

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this work, we report a comprehensive study on developing high performance magnesium phosphate cement (MPC) composite bipolar plates for fuel cells. The MPC composite bipolar plates composed of MPC with partial replacement of fly ash as the binding matrix phase and multiple carbon-based materials (including graphite, carbon fiber and multi-walled carbon nanotubes) as the conductive phase. A simple hot-press process was applied to produce the MPC composite. After the optimization on the formula and the structure of the MPC composite and the processing parameters, all the US DOE 2015 technical targets, including electrical conductivity, flexural strength, corrosion resistance were …

A Displacement Controlled Fatigue Test Method For Additively Manufactured Materials, Mohammad Masud Parvez, Yitao Chen, Sreekar Karnati, Connor Coward, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

A novel adaptive displacement-controlled test setup was developed for fatigue testing on mini specimens. In property characterization of additive manufacturing materials, mini specimens are preferred due to the specimen preparation, and manufacturing cost but mini specimens demonstrate higher fatigue strength than standard specimens due to the lower probability of material defects resulting in fatigue. In this study, a dual gauge section Krouse type mini specimen was designed to conduct fatigue tests on additively manufactured materials. The large surface area of the specimen with a constant stress distribution and increased control volume as the gauge section may capture all different types …

A Framework Of Integrating Manufacturing Plants In Smart Grid Operation: Manufacturing Flexible Load Identification, Md. Monirul Islam, Zeyi Sun, Wenqing Hu, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

In the deregulated electricity markets run by Independent System Operator (ISO), a two-settlement (day-ahead and real-time) process is typically used to determine the electricity price to the end-use customers at different buses. In the day-ahead settlement, the demand is predicted at each bus based on the previous consumption behavior of the consumers and thus, Locational Marginal Price (LMP) can be determined and shared to the consumers. A significant gap is usually observed between the planned and real-time demands due to the uncertainties of the weather (temperature, wind-speed etc.), the intensity of business, and everyday activities. Therefore, a large price variation …

Infrared Glass–Ceramics With Multidispersion And Gradient Refractive Index Attributes, Laura Sisken, Myungkoo Kang, Johann M. Veras, Charmayne Lonergan, Andrew Buff, Anupama Yadav, Devon Mcclane, Cesar Blanco, Clara Rivero-Baleine, Theresa S. Mayer, Kathleen A. Richardson

Materials Science and Engineering Faculty Research & Creative Works

Infrared (IR) glass–ceramics (GCs) hold the potential to dramatically expand the range of optical material solutions available for use in bulk and planar optical systems in the IR. Current material solutions are limited to single- or polycrystalline materials and traditional IR-transparent optical glasses. GCs that can be processed with spatial control and extent of induced crystallization present the opportunity to realize an effective refractive index variation, enabling arbitrary gradient refractive index elements with tailored optical function. This work discusses the role of the parent glass composition and morphology on nanocrystal phase formation in a multicomponent chalcogenide glass. Through a two-step …

Ionic Conductivity Behavior By Activated Hopping Conductivity (Ahc) Of Barium Aluminoborosilicate Glass–Ceramic System Designed For Sofc Sealing, M. J. Da Silva, W. M. Pontuschka, J. F. Bartolomé, P. Jasinski, J. Karczewski, Signo Tadeu Dos Reis

Materials Science and Engineering Faculty Research & Creative Works

Non-conducting BaO-B₂O₃ -Al₂O₃ -SiO₂ parent glasses designed for solid oxide fuel cell (SOFC) sealing applications were prepared using the melt-quenching technique. The glass formation region was determined according to phase equilibrium relations and was found to be in the composition range 70BaO-(x) Al₂O₃ -(10−x) B₂O₃ -₂₀SiO₂ where 3.0 < x < 6.0 wt.%. The conductivity values obtained conductivity ranged from 10 −5 to 10 −10 S/cm at temperatures between 600 and 850 °C. The batch compositions presented a threshold of dc conductivity near 70BaO wt% with a quasi linear behavior with the decrease of the BaO content. Different values of conduction activation energy were observed at temperatures above the glass transition temperature (T g ) (up to 700 °C), which were attributed to the thermal bond-breaking of non-bridging oxygen (NBO) defects. The experimental results of the electrochemical characterization by impedance spectroscopy of glass–ceramic interfaces with yttria-stabilized zirconia (YSZ) acting as solid ionic conductor electrolyte are presented and discussed.

Detection Of Sensor Attacks In Uncertain Stochastic Linear Systems, Chandreyee Bhowmick, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel attack detection scheme is developed for linear discrete-time systems with unknown dynamics that are subject to the additive process and output measurements noise. A novel stochastic adaptive observer is proposed to estimate the state vector in the presence of noisy sensor measurements and uncertain dynamics, and also to generate the innovation signal to detect attacks using a modified $\chi2} $ detector. It has been shown that the innovation signal, which is defined as the difference between the measured and the estimated output from the observer, has a Gaussian distribution with non-zero mean. The modified $\chi^ {2} $ detector …

Attack Detection In Linear Networked Control Systems By Using Learning Methodology, Haifeng Niu, A. Sahoo, C. Bhowmick, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

A novel learning-based attack detection scheme for linear networked control systems (NCS) is introduced. The class of attacks considered here tends to increase network induced delays and packet losses which affects the physical system dynamics. For the network side, an adaptive observer is proposed to generate the attack detection residual, which in turn is utilized to determine the onset of an attack when it exceeds a predefined threshold. The uncertain stochastic physical system dynamics as a result of network-induced delays of packet losses require an optimal Q-learning based event-triggered controller that optimizes the control policy and the event-triggering instants simultaneously. …

Triple-Junction Solar Cells : In Parallel., Levi C Mays

Electronic Theses and Dissertations

This paper looks into the current inefficiency of solar cells and attempts a few alternative solar cell structures in order to provide a more effective source of renewable energy. Currently, multi-junction solar cells are being developed to capture the sun’s light more efficiently. One of the ideas in this paper is to add a window to see if the addition of such a layer into a junction will increase the voltage while maintaining nearly the same current output. Central to this paper is the rearranging of the conducting layers of the multi-junction cell so that the junctions can be connected …

Purification Of Biomass Hydrolyzates For The Promotion Of Xylose Diester Formation, Laura Fernandez

Electronic Theses and Dissertations

The application of a novel xylose isolation procedure using phenyl boronic acid esterification has been limited to the hydrolyzates of low extractive biomasses like hardwoods and agricultural resides. Hydrolyzates with lower sugar and higher extractive concentrations, like softwoods, have not yielded xylose, or even xylose diester (XDE), the first intermediate product in the new process, under the same conditions. This research applied evaporation concentration, adsorbent separation and membrane filtration to these lower performing biomass hydrolyzates to maximize the yield of the XDE formation step of the new xylose extraction process. Lab-scale tests of these techniques were applied to pine hydrolyzate …

Fluid Flow Analysis Of Diluted Evaporating American Whiskey Droplets., Martin J. Brown Vi

Electronic Theses and Dissertations

The recent discovery of the unique structures, whiskey webs, formed when the evaporation of diluted American whiskey, has raised many questions as to the nature of the structures. Their formation process follows as such: (1) dilution of the whiskey to form nanoaggregates, (2) formation of a monolayer at the air-liquid interface, (3) chaotic ethanol evaporation caused monolayer collapse (via dynamic pressure), (4) bulk fluid evaporation caused monolayer collapse (via reduction of surface area), where the web-like structures reside on the surface, and finally, (5) web-like structures deposit on the substrate. The webs imaged via SEM had a striking resemblance to …