Engineering Commons^™

Real Time Pii Scanning, John David

Electronic Theses and Dissertations

The increased amount of web applications and internet software solutions utilizing cloud frameworks has contributed to large data sets of system log messages being generated constantly. These messages may contain sensitive data, creating an additional security risk for the systems and contributing to the need for analysis of such large volumes of data in real time. Large commercial data monitoring systems can solve for these analysis requirements, but they can be costly. We present a solution to analyzing web application log data which ingests it, processes it and visualizes sensitive data found within in real time. Our solution utilizes an …

Heterogeneous Multi-Robot Person-Following In Constrained Environments, Ori A. Miller

Electronic Theses and Dissertations

Maintaining visibility of a person requires effective systems. Security cameras or ground robots might be ideal, but they often fail in uncontrolled or unknown environments. A single ground robot struggles to navigate and track an agent at the same time. This work addresses the challenge by developing a multi-robot system with a slow ground robot and an agile aerial robot. Three methods are evaluated: FORWARD-PF, RL-Person Following (RL), and a baseline closed-loop method. FORWARD-PF proved the most reliable, completing all nine paths and reaching targets nearly twice as fast as RL. Despite completing seven paths, RL faltered on complex tasks. …

Koopman-Based Modeling For Nonlinear Control Of Multirotor Uavs, Simone Martini

Electronic Theses and Dissertations

This PhD dissertation focuses on adopting the emerging Koopman Operator theory for modeling and nonlinear control of multirotor UAVs, focusing specifically on quadrotors for proof-of-concept demonstration purposes.

The Koopman Operator theory is based on the foundation that nonlinear dynamics in the state space may be represented as a linear evolution of some functions in the state space. Thus, using appropriately defined and possibly nonlinear functions of the state variables, called observables, as a new and maybe infinite set of coordinates that are referred to as lifted space, the original nonlinear dynamics appear to be linear. The implications of this theory …

Integrating Authentication Schemes In Augmented And Virtual Reality Classrooms, Naheem Noah

Electronic Theses and Dissertations

Augmented Reality and Virtual Reality (AR/VR) technologies are revolutionizing educational experiences, but their widespread adoption hinges on addressing critical security and usability challenges, particularly in the domain of user authentication. This research presents an investigation into the security landscape of AR/VR and explores a graphical authentication scheme called “Things” that enhances both security and usability in immersive learning environments. Through a systematic evaluation of popular AR/VR devices and applications, potential vulnerabilities and limitations were identified, such as high usage of pin/passwords which are susceptible to shoulder-surfing attacks, lack of multi-factor authentication, and unclear data-sharing practices. A review of existing knowledge-based …

Denoising And Super-Resolution Of In-Vitro 4e Flow Mri In A Stenotic Phantom Model Using Physics-Informed Neural Networks., Shrouk M. Wally

Electronic Theses and Dissertations

In recent years, the use of 4D flow MRI has revolutionized cardiovascular imag- ing by providing comprehensive data on blood flow dynamics over time. However, the limited spatial and temporal resolution of this imaging modality can hinder the accurate assessment of complex hemodynamic phenomena. This thesis explores the application of Physics-Informed Neural Networks (PINNs) to enhance the resolution of 4D flow MRI data, thereby improving its clinical utility. PINNs are a class of neural networks that integrate physical laws into their training process. By embedding these physics equations, PINNs can discover the underlying physics of fluid dynamics to produce more …

Novel Sensors, Algorithms And Metrics For Human-Robot Interaction., Henry Lee Reynolds

Electronic Theses and Dissertations

The increased presence and deployment of robotics in sectors such as the medical field results in the demand for robots to, directly and indirectly, interface with people and their environment, making human-robot interaction (HRI) a vital thrust of robotics research. Assistive robots, for example, aid humans in accomplishing tasks or by providing support in the workforce. As the demand for nurses and the aging population increases, the assistive robots deployed will be deeply rooted in environments that require constant interaction with humans. This work contributed to improving aspects of HRI through 1) Expanding accessibility of the methods used for interfacing …

Analysis Of The Relationship Between Flow Patterns In The Post-Stenotic Region Of Model Arteries And Stenosis Severity., Michael Laroche

Electronic Theses and Dissertations

In this study, contour fields of mean age and turbulence kinetic energy (TKE) in the post-stenotic region of model arteries were analyzed to explore their correlation with FFR. While both high and low FFR cases exhibited similarities with an inner low-age region and an outer high-age region, low FFR cases displayed asymmetry in their low-age regions due to eccentric stenosis. Moreover, gradients of age across the artery diameter were more pronounced for low FFR cases. Additionally, low FFR cases demonstrated significantly higher TKE in the post-stenotic blood jet stream compared to high FFR cases that are reflected in low-age boundary …

Carboxen Micropreconcentrator Performance For Analyzing Btex In Air., Raymond Daniel Spargo

Electronic Theses and Dissertations

Volatile Organic Compounds (VOCs) are a class of toxic chemicals in environmental air associated with several serious health risks. Some of the most common and concerning VOCs are Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX). To maintain healthy air quality in these environments, researchers pursue instruments and processes to quickly and accurately predict sub-ppb concentrations of BTEX in indoor and outdoor air. By employing a micropreconcentrator (μPC) to combine Solid-Phase Micro-Extraction (SPME) with Gas Chromatography Mass Spectrometry (GC-MS) analysis, trace BTEX content in air samples can be captured, extracted and analyzed. In this thesis, a dual-compartment μPC with Carboxen 1000 …

The Impact Of Internal Curing Additives On Compressive Strength, Shrinkage, And Internal Relative Humidity Of Mortars., Payton Scott

Electronic Theses and Dissertations

Curing is a critical step in concrete construction. When a concrete specimen is properly cured, its shrinkage and early age curling/warping can be reduced, and the concrete strength can be increased. Curing methods can be divided into two categories: traditional external curing and emerging internal curing methods. Internal curing has similar benefits to external curing, such as reduced early-age cracking and shrinkage risk, and increased durability and strength. The purpose of this research is to investigate internal curing additives and their impact on length change, weight change, compressive strength, autogenous shrinkage, and internal relative humidity. Mortar mixtures with lightweight aggregate …

Development And 3d Printing Of Glass Fiber And Carbon Fiber Reinforced Shape Memory Polymer Composites For Structural Applications., Krishna Sai Aparna Munjuluri

Electronic Theses and Dissertations

This study aims at the development of shape memory polymer composites with two types of reinforcements, milled glass fibers, and chopped carbon fibers, for potential structural applications in aircraft and automotive industries. Glass fiber-SMP composites were made at fiber loading wt.% of 0%, 5%, 10%, and 20%. In contrast, carbon fiber-SMP composites were made at fiber loading wt.% of 0%, 5%, 10% and 15%. The feedstocks were extruded into filaments and characterized by their physical, rheological, chemical properties and morphologies. Fused Filament Fabrication 3D printing was used to manufacture specimens for mechanical testing of hardness and flexural properties. The findings …

Reinforcement Learning Assisted Communication Resources Optimization In Advanced Air Mobility., Ruixuan Han

Electronic Theses and Dissertations

Advanced air mobility (AAM), which envisages a safe and efficient aviation transportation system, has drawn significant attention to support the increasing mobility demand in metropolitan areas. Communication services for AAM aerial vehicles (AVs) are crucial for ensuring flight safety. This dissertation explores three research topics on communication resource allocation problems in AAM applications. The first topic, addressed in Chapter II, investigates the joint velocity selection and spectrum allocation problem for AAM applications to enhance spectrum utilization efficiency (SUE). In the AAM scenario, multiple AVs travel along predefined paths for passenger and cargo deliveries. Given that AAM aims to provide fast …

Virtual Engagement: Can Law Enforcement Benefit From Utilizing Extended Reality In Their Training Systems?, Jacob Maxwell Read

Electronic Theses and Dissertations

Introduction: Extended reality (XR) technologies offer innovative training solutions for various industries, including healthcare, manufacturing, aviation, sports, military, and law enforcement. XR can provide a solution for training where job tasks are difficult or near impossible to train in real-life. A human factors research and design approach could provide an effective, low-risk, and cost and time-efficient option for integrating the use of XR technology into training for many industries. To advance this goal, this research answered two main research questions: (1) What training needs/challenges are best suited for an XR training system designed for law enforcement officers (LEOs)? (2) …

Deep Reinforcement Learning-Based Dynamic Routing And Spectrum Access In Aeronautical Networks., Zhe Wang

Electronic Theses and Dissertations

As the airspace is experiencing an increasing number of aircraft, spectrum sharing among Air Vehicles (AVs) and Terrestrial Users (TUs) emerges as a compelling solution to improve spectrum utilization efficiency. I investigated three types of aeronautical communication including the single-hop Air-Air Communication Network (AACN), the multi-hop Air-Air Ad-hoc Network (AAAN), and the Aerial and Terrestrial Hybrid Network (ATHN). I assume a spectrum-limited scenario through all communication networks. Thus, the number of communication pairs is greater than that of the available channels, resulting in co-channel interference due to the reuse of the same channel among communication links. In a single-hop AACN, …

Epidural Stimulation For Urogenital Dysfunction In The Spinal Cord Injured Rat., Natasha Lorraine Wilkins

Electronic Theses and Dissertations

Spinal cord injury (SCI) is a devastating, life changing event that greatly impacts quality of life. SCI can have body-wide, multi-system consequences including dysfunction within the urogenital system. Challenges with the urinary system include urinary incontinence, urine retention, and detrusor-sphincter dyssynergia all of which require maintenance through the regular use of catheters. Sexual dysfunction in men, who comprise nearly 80% of the SCI population, includes erectile dysfunction, anejaculation, retrograde ejaculation, poor expulsive force during ejaculation, and poor sperm quality. The treatment for sexual function in SCI men is focused more on fertility through the collection of sperm for insemination procedures …

Constant-Ph Molecular Dynamics At Inorganic Interfaces: Adding A New Dimension To Simulations Of Interfacial Phenomena., Ted Kalbfleisch

Electronic Theses and Dissertations

This dissertation explores the application of novel molecular dynamics simulation methods to better understand complex systems, with a particular focus on silica materials and protein interactions. Silica materials, known for their versatile surface and solution chemistries, play critical roles in catalysis, chromatography, and wastewater treatment. Despite their widespread use, the molecular-level interactions between silica surfaces and their environments remain poorly understood. To address this knowledge gap, we employed λ-dynamics enabled constant pH molecular dynamics to dynamically model protonation and deprotonation events on silica surfaces. Traditional experimental techniques such as x-ray crystallography, NMR, and cryo-EM are inadequate for probing structures in …

Natural Fiber Reinforced Composites For Sustainable Additive Manufacturing., Athira Nair Surendran

Electronic Theses and Dissertations

Carbon fiber is widely known for its exceptional strength, making it a sought-after material in composite manufacturing, especially with thermosets and thermoplastics. Its major applications span aerospace, wind turbines, sports equipment, automotive interior and exterior parts, robotics and medical equipment. Recently, carbon fiber filament manufacturing has gained attention due to the availability of desktop 3D printers and the versatility and customizability that comes with the realm of 3D printing. Commercial carbon fiber production, primarily from polyacrylonitrile (PAN), is energy-intensive and derived from crude oil, contributing to significant environmental impacts and poor recyclability. Alternatively, lignocellulosic natural fibers present a possible sustainable …

Adaptive Robot Collaboration Using Robotic Skin And Motion Similarity., Jordan Dowdy

Electronic Theses and Dissertations

An essential part of robotics research is human-robot collaboration, which enables the use of current and new robots in everyday life and the workforce. This research applies to both parts of human-robot collaboration: physical human-robot interaction (pHRI), as well as non-physical human-robot interaction. The physical interaction uses tactile sensors and a Neuroadaptive Controller (NAC) to allow for the guidance of a robotic arm and its end-effector. The non-physical interaction uses a novel motion similarity metric, the Cartesian Segment Online Dynamic Time-Warping (SODTW), to allow a robot to better adapt to the speed of the user performing the motion during imitation …

Development And Processing Of Shape Memory Polymer Composites (Smpcs) For Application In Structural Robotics And Robotic Sensors., Kavish Sudan

Electronic Theses and Dissertations

Shape Memory Polymers (SMPs) have attracted significant attention since their introduction in the 1980s due to their remarkable ability to regain their original shape from a temporarily deformed state when exposed to an external stimulus, typically heat. This shape memory effect, driven by thermal transitions such as the glass transition temperature (T_g) or melting temperature (T_m), has made SMPs highly attractive for applications in soft robotics, aerospace, and biomedical devices. However, SMPs face challenges such as limited mechanical strength, thermal stability, and electrical conductivity, which hinder their broader adoption in advanced applications. To address these challenges, …

Synergistic Strategies In Hybrid Mxed Matrix 3d Printing Of Thermoplastics & Thermosets: Design, Manufacturing, And Materials Development., Saleh Akram Khanjar

Electronic Theses and Dissertations

Composite manufacturing and mixed matrix structures have been produced using traditional manufacturing processes for various industrial applications due to their high mechanical properties to material weight and cost ratio. However implementation of composite and mixed matrix manufacturing with advanced manufacturing such as additive manufacturing is limited due to the hardware limitations of current 3d printing technologies and materials available for 3D printing applications. This work has developed and investigated a new hybrid 3D printing manufacturing process utilizing a variety of material systems (thermoplastic – thermoset, thermoplastic – thermoplastic, thermoset – thermoset, thermoplastic – thermoplastic – thermoset). This study developed thermoplastic …

Bridging Design And Perception: Novel Tools And Technologies For Creating Effective Human-Robot Interactions, Benjamin Dossett

Electronic Theses and Dissertations

This thesis explores human perception of robots through the use of novel tools and technologies. First, the impact of Augmented Reality (AR) data presentation on human perception of robots is investigated. A study conducted with the AR human-robot teaming system found that robot performance significantly influenced participants’ perceptions, overshadowing the impact of matching or mismatching robot confidence feedback. Second, the DU Want to Build-A-Bot platform is presented, which enables participatory robot design and opens the door for novel research of how robot design affects human perception. The Build-A-Bot platform enables the collection of diverse robot designs, facilitating machine learning analysis …

Incremental Quantities Based Permissive Overreaching Transfer Trip Scheme For Protecting Inverter-Based Renewable Resources, Osama Zangoti

Electronic Theses and Dissertations

The power generation landscape evolves, with the increase of inverter-based resources (IBRs) such as solar photovoltaics and wind turbines, providing sustainable and clean energy sources. The shift towards IBRs mitigates climate change, creating considerable challenges to traditional power system protection due to their low fault current. Conventional protection schemes are designed around the internal dynamic of synchronous generators where they can supply an elevated fault current. This thesis explores a protection scheme designed to enhance the security of IBRs. The incremental characteristics of voltage and current coupled with the Permissive Overreaching Transfer Trip scheme (POTT) provide a remarkable ability to …

Spin And Charge Transport In Metallic Ferrimagnets And Disordered Magnetic Oxides, Leopoldo A. Hernandez

Electronic Theses and Dissertations

Recent efforts have been exploring the use of thin film synthetic ferrimagnets and disordered magnetic oxides for applications in spintronic devices. Due to the antiferromagnetic exchange interaction, ferrimagnetic materials offer the ultrafast dynamics of the antiferromagnetic exchange, with a net magnetization that can be influenced externally. With two, or more, competing ferromagnet sublattices, interesting properties arise that depend on the final magnetic landscape after growth of the material and it’s inherent magnetic anisotropy energies. Properties such as magnetic compensation temperatures, and perpendicular magnetic anisotropy are attractive for applications in spintronic memory and logic devices, some already being implemented in MRAM …

Effect Of Oxidation Of Graphene On Agglomeration And The Mechanical Properties Of Thermosetting Resins, Matthew A. Reil

Electronic Theses and Dissertations

Thermosetting resins are used extensively worldwide in applications ranging from adhesives to structural components. However, these resins generally fail in a brittle fracture mode which is undesirable in most situations. Graphene (G) and its derivatives have been considered as additives to epoxy for material property enhancement and varied results have been reported in the literature. In this work, the effects of the oxidation of G to graphene oxide (GO) on polymer interactions and plate agglomeration were studied by classical molecular dynamics (MD). Results from those simulations concluded that agglomerates were likely present in all G-based nanocomposites. The effect of these …

Patient-Specific Musculoskeletal Modeling Of Total Shoulder Arthroplasty, Brendan M. Curran

Electronic Theses and Dissertations

Total shoulder arthroplasty (TSA) is often considered a surgery of last resort for patients with debilitating pathologies of the glenohumeral joint such as osteoarthritis, humeral head fracture, and advancing rotator cuff tears. TSA replaces the articulation between the humeral head and the glenoid fossa, with the goals of relieving pain and restoring function. Two types of total shoulder implants are available: Anatomic Total Shoulder Arthroplasty (aTSA) and Reverse Total Shoulder Arthroplasty (rTSA). TSA survivorship is lower than that of the survivorship seen in total knee and hip replacements [1]. Shoulder muscle moment arms and lines of action have been measured …

Statistical Modeling Of Knee Morphology And Material Properties Considering Diverse Populations, Gabrielle Jeannine Kindy

Electronic Theses and Dissertations

Total Knee Arthroplasty (TKA) is a widely performed surgical procedure aimed at alleviating pain and restoring function in patients with severe knee osteoarthritis. Despite its general success, disparities in postoperative outcomes have been observed across different racial and ethnic groups, with minority populations often experiencing less favorable results. One potential avenue for improving the generalizability of orthopaedic implants is using Statistical Shape and Intensity Models (SSIMs), which can be used to incorporate patient variability directly into the orthopaedic medical device development workflow through population-based finite element analysis.

This work aimed to construct an SSIM from a diverse subject set, incorporating …

Stimuli-Responsive Glycopolymeric Nanoparticles To Boost Tumor Immunogenicity Through Macrophage-Targeted Therapy, Oluwaseyi Shofolawe-Bakare

Electronic Theses and Dissertations

Tumor-associated macrophages (TAMs) play a substantial role in sculpting the tumor microenvironment (TME) into an immunosuppressive bastion that undermines immune surveillance and enables tumor progression. They therefore represent a promising therapeutic target to make the TME more conducive for anti-tumor immunity and greatly improve treatment outcomes in cancers that are highly resistant to conventional forms of therapy. Several medications have been developed to modulate the activities of TAMs, showing tremendous potential, but these medications lack specificity for TAMs making their use susceptible to adverse side effects that could outweigh prospective benefits. Sophisticated delivery vehicles that can preferentially deliver these medications …

Development Of A Rapid Bacterial Quantification Method Based On Droplet Microfluidics, Shawn Bliss

Electronic Theses and Dissertations

The capacity to identify bacteria quickly and accurately is critical for applications such as medical diagnosis, environmental monitoring, and food safety. For instance, sepsis diagnosis requires blood cultures that take as long as 1-5 days, preventing timely intervention and increasing mortality rate. Here, we propose the joint use of microfluidics and a machine learning algorithm for rapid bacterial cell capture and quantification. The combination of high-throughput droplet microfluidics and a support vector machine (SVM) enables analysis and quantification of bacterial samples within as short as 4 hours. We have performed successful encapsulation of pathogenic bacteria such as E. coli, …

Smart Manufacturing Of Cement: From Lab-Scale Simulation And Testing To Industry-Scale Deployment., Juan David Tabares Tamayo

Electronic Theses and Dissertations

Cement kilns are controlled by experienced process operators who follow experience-based industry guidelines using data collected and fundamental knowledge. The manufacturing process, which is equipped with sensors and equipment, transfers data/information to the operators to aid standardized decision-making operations. In contrast, companies have used such data to develop and implement digital solutions for predictive control systems; in effect, FLSmidth and Rockwell Automation. However, despite the availability of automated control systems and investigation in automation for process monitoring and optimization, opportunities to radically optimize cement manufacturing are still abundant and in need of implementation. Therefore, this research developed simulation models and …

Fly Ash Based Geopolymer: Water, Curing Temperature And, Cao Content Effects On Microstructure And Compressive Strength., Lujain Salem

Electronic Theses and Dissertations

Geopolymer, an emerging alternative to Portland cement-based concrete, relies on alumina and silica-rich precursors like fly ash for its formation. Geopolymerization is a chemical process that creates a three-dimensional polymer network by reacting with an alkaline activator. While fly ash's calcium oxide (CaO) content is crucial in its classification, it behaves differently in geopolymerization, where it competes with hydration. Therefore, a better understanding of the impact of CaO content in fly ash on geopolymerization is needed to effectively utilize fly ash. This study investigates the effects of CaO content, water, and curing temperature on geopolymerization. Using fly ash from a …

In-Training Explainability Frameworks To Make Black-Box Machine Learning Models More Explainable., Asuman Cagla Acun

Electronic Theses and Dissertations

Despite ongoing efforts to make black-box machine learning models more explainable, transparent, and trustworthy, there is growing advocacy for using only inherently interpretable models for high-stake decision-making. Post-hoc explanations have recently been criticized for learning surrogate models that may not accurately reflect the actual mechanisms of the original model and for adding computational burden at prediction time. We propose two novel explainability approaches to address these limitations: pre-hoc explainability and co-hoc explainability. These approaches integrate explanations derived from an inherently interpretable white-box model into the learning stage of the black-box model without compromising accuracy. Unlike post-hoc methods, our approach does …