Engineering Commons^™

Accident Data Analytics And Ai-Based Auditory Enhancement For Highway Construction Safety, Thinh Nguyen

All Dissertations

This research develops data-driven and AI-enhanced approaches to improve worker safety in highway construction environments. The study integrates advanced analytics and auditory signal enhancement to identify high-risk worker behaviors and improve real-time safety warnings. The work consists of three core studies. The first study applies Sequential Pattern Mining and Social Network Analysis to more than 1,000 construction accident reports to identify high-risk worker actions and their hidden sequential relationships with accident types and consequences. These insights reveal sector-specific risk patterns, supporting the creation of targeted, data-informed safety interventions. The second study introduces an AI-based auditory enhancement model built on a …

Degradation Of Cobalt Chrome Molybdenum Hip And Knee Implants In Vivo And In Vitro, Peter William Kurtz

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Cobalt Chrome Molybdenum (CoCrMo) remains a popular material choice for femoral condyles in total knee arthroplasty and for acetabular liners in dual mobility total hip designs. CoCrMo has been phased out of conventional THA designs due to its correlation with adverse effects such as ALTR and ALVAL. It is less understood if the mechanisms (i.e. abrasive wear to the surface of the implant) that release metal ions into the surrounding tissue occur at similar rates as seen in conventional THA. Additionally, it is unknown what effect the secondary damage modes such as electrocautery damage and adhesive wear have on these …

Particle Migration In Non-Newtonian Fluid Flows Through Curved Microchannels, Sanskruti Ramesh Raut

All Dissertations

Innovations in microfabrication over the past three decades have enabled the development of microfluidic devices with intricate channel geometry. Microfluidic platforms offer controlled manipulation of fluids and particles by leveraging the internally induced and/or externally imposed force field(s). The demand for compact microchannel geometry has turned the attention toward curved microchannels with significantly reduced footprints. However, most of the previous studies in curved microchannels have been limited to particle migration in Newtonian fluids. The influence of fluid rheology has remained largely unexplored.

In the first part of this dissertation, we present a systematic experimental study on the influences of fluid …

Universal Systems Simulation Via Constraint Hypergraphs With Applications To Digital Twins, John Morris

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The characterization of systems encompasses a variety of modeling frameworks designed to capture specific behaviors and components of various system domains. Whatever the framework, the core elements of a system representation are the information of the system and a description of how that information is related. The relations in deterministic systems are functions, which, when composed to form executable processes, can be used to simulate system data. A declarative modeling framework is one that encodes mechanisms for preparing these simulations within the model structure, allowing an external agent to form the execution processes required for a given context. To date, …

Thermal Management Of Power Electronic Converters In Electric Motor Drives Using Active Thermal Control And Active Cooling, S M Imrat Rahman

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The application of power electronic converters (PEC) in electric vehicles (EVs) has significantly increased due to their enhanced controllability and flexibility. Additionally, Permanent Magnet Synchronous Machines (PMSMs) are favored in EVs for their higher torque, efficiency, performance, and heat dissipation capabilities compared to asynchronous machines. The reliable operation of power converters in PMSM drives is crucial for EV operation, and this is driving interest in developing innovative and sustainable technologies that ensure the safe and reliable functioning of PECs. One of the main challenges in achieving reliable PECs is designing effective thermal management systems to control junction temperature and reduce …

A Study On Utilizing Coherently Coupled Orbital Angular Momentum Beams For Maritime Sensing And Communication, Evan Robertson

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A large portion of the world is covered in water which introduces a couple of key challenges in communication and sensing systems. The impact of particulates in the water will limit the ability to successfully transmit information through the water. The study of how the channel impacts specific frequencies and the ability to transmit more information at a single time can limit the impact of this environment in how it degrades an optical communication system. In sensing applications, it is important to detect information related to an object’s motion which will either be towards or away from a system, or …

Complementary Color Laser Illumination For Perceptual Contrast Enhancement In Structurally Colored Samples, Tomoshree Dash

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Structural color, a phenomenon arising from nanoscale interaction between light and materials, has the potential to unveil biological, chemical, physical, and mechanical characteristics of the sample. It enables direct visualization of the sample by human users with high spatiotemporal resolution. However, its impact is often constrained by challenges in the perceptual differentiation of subtle color variations. This thesis introduces complementary color laser illumination (C²LI) as an imaging technique that enhances color perception of the Human Visual System (HVS) by accessing the psychophysical non-linearities in chromatic color perception. C²LI offers a platform optimized for the HVS by …

Diabetes-Induced Mitral Valve Degeneration: Tissue-Engineered Solutions And Antioxidant Therapy, Samantha Hahn

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Mitral valve (MV) fibrosis is a progressive pathological condition characterized by leaflet thickening and stiffening, ultimately compromising valve function. This process is accelerated in diabetes, where chronic hyperglycemia elevates reactive oxygen species (ROS) and alters the mechanics of the extracellular matrix (ECM), collectively promoting the activation of valvular interstitial cells (VICs). Under healthy conditions, VICs maintain a quiescent, fibroblast-like phenotype responsible for sustaining ECM homeostasis. However, pathological biochemical cues or mechanical stress drive VICs toward a myofibroblast phenotype. While this transformation is essential for short-term repair, its persistence contributes to maladaptive MV remodeling and fibrosis. Diabetic stressors may be mitigated …

Mitral Annular Calcification In Diabetes: Valvular Interstitial Cells, Antioxidant Therapy, And Tissue Engineering Approaches, Raleigh J. Keenan

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Mitral annular calcification (MAC) is a chronic, progressive, and degenerative condition that impairs mitral valve function and increases the risk of cardiovascular disease. The mitral annulus is a saddle-shaped, fibrous structure that is primarily composed of collagen and elastin. The annulus also contains interspersed lipids that are involved in cellular metabolism, as well as inflammatory and osteogenic signaling. These lipids increase the annulus’ susceptibility to calcification, under conditions that increase mechanical stress (hypertension) and promote atherosclerosis (diabetes mellitus). These conditions intensify calcification by promoting the activation of valvular interstitial cells (VICs), increasing fibrosis, and inducing osteogenic differentiation. Although it is …

The Iron Pyramid: Expanding The Iron Triangle To Integrate Safety As A Fundamental Dimension Of Construction Success, Laura Cooley

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For more than fifty years, construction project success has been judged by staying on schedule, remaining within budget, and completing the planned scope of work—an approach commonly known as the “Iron Triangle” (Barnes, Ph.D., 2006). While these measures are important, they do not capture the full range of factors that determine whether a project truly succeeds.

This study introduces the “Iron Pyramid” (Cooley, 2025), a model that expands the traditional framework by adding a fourth dimension: safety. Safety is understood not simply as regulatory compliance or the absence of injuries, but as a holistic construct encompassing project culture, leadership practices, …

Experimental And Numerical Study On The Influence Of Carbon Fiber Reinforcement On The In-Plane Compressive Properties Of 3d Printed Hexagonal Honeycomb Core Structures, Deon Wallace

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There is difficulty with numerically replicating the behavior of composite honeycomb core structures numerically due to the trouble of gathering material properties from a hollow structure. Also, complex part geometries and carbon fiber reinforcement strategies can lead to unwanted structural weaknesses and variance in material properties that may not be reflected in numerical analysis when the part is additively manufactured. In this study, edgewise compressive testing is used to characterize the mechanical behavior and performance characteristics of these structures. The experimental results indicate an increase in the Young’s moduli of the honeycomb core structures as carbon fiber concentration increases. However, …

Tradespace Exploration For Multiple Collaborative Vehicles, Mrunal Deshmukh

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Modern military operations demand systems that adapt to uncertain, rapidly changing missions across diverse terrains. Traditional single-platform vehicle design is insufficient for such complexity. This research introduces a hierarchical tradespace exploration framework for designing and evaluating families of heterogeneous ground vehicles under a System-of-Systems (SoS) architecture. The framework treats vehicle design as a co-optimization problem, where a “parent” vehicle (e.g., a Squad Multipurpose Equipment Transport) coordinates specialized “child” vehicles for reconnaissance, amphibious tasks, terrain traversal, and stealth missions. Unlike conventional approaches that optimize vehicles individually, this study emphasizes collaborative performance, resource sharing, and adaptability at the family level. Central to …

Experimental Determination Of Modulus Of Rupture For Concrete Masonry Beams And Implications For The Tms 402/602 Code, Shreedhar K C

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Currently, the experimental database for Modulus of Rupture (MOR) of masonry beams is limited, and current provisions in TMS 402/602-22 use the MOR values from wallette tests. The primary goal of this research is to experimentally determine the parameters that influence MOR. The secondary goal of this work is to compare the MOR values from beam and bond wrench tests obtained in this study with each other as well as with values published in the literature. The standard ASTM E518 test was used for determining MOR values for beams, and a modified approach to ASTM C1072 that nullifies the eccentricity …

Dynamic Topology Optimization And Experimental Validation Of Reinforcement For Pcb Robotics, Ryan G. Semler

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Ongoing research between Clemson University and the NASA Jet Propulsion Laboratory (JPL) has been conducted to characterize and assess rigid-flex printed circuit board (PCB) robotics subjected to dynamic loads. A lightweight, PCB lunar rover, PUFFER (Pop-Up Flat Folding Explorer Robot), was designed by NASA JPL for Mars missions, but its deployment for lunar missions has been investigated as well. Its current architecture, however, is insufficient for navigating and surviving the lunar environment, and reinforcement has been recommended as a solution to protect larger panels.

This research work presents a dynamic topology optimization process for PCB panel reinforcement. A thorough literature …

Editable 4d Gaussian Splatting: Scalable And Consistent Video Editing Via Uv-Texture Decomposition, Shuai Lyu

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Dynamic 3D videos are now widely used in VR, AR, and telepresence, where users often want to change the style or appearance of objects such as clothing over a whole sequence. However, editing such dynamic 3D content is still hard, because appearance, geometry, and motion are tightly coupled, so even a simple color change must stay consistent in all views and at all time steps. Existing editing methods based on 4D Gaussian Splatting often work in a frame-by-frame way, which is slow and makes it difficult to keep temporal and multi-view consistency.

This thesis proposes Editable-4DGS, a representation-centric framework that …

Barriers To Modernizing Aviation Maintenance Technician Education To Meet Emerging Industry Needs, Durwa Chavan

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Modernizing aviation maintenance education is essential to keep pace with emerging technologies, including electric propulsion systems and advanced avionics. As aircraft systems become more digitized and interconnected, there is a growing demand for qualified technicians who can conduct advanced diagnostics and maintenance. However, training programs have not kept pace with these technological shifts, creating a gap between workforce preparation and industry needs.

Using a qualitative research approach, this study conducted semi-structured interviews with industry professionals, educators, and regulatory personnel to identify gaps in existing training programs and Airman Certification Standards (ACS). This study addresses the disconnect between current aviation maintenance …

Predicting Long-Term Creep Behavior Using Short-Term Stress Relaxation Data In Expanded Polyethylene Foam, Andrew M. Seelig

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Closed cell expanded polyethylene (EPE) foams are widely used for protective packaging due to their high energy absorption properties and recyclability. However, these foams can be subjected to sustained compressive stresses (13.78 - 36.20 kPa), depending on density and application, leading to time-dependent deformation (creep). Creep reduces cushioning performance, making its understanding critical for effective protective packaging. Two standards, ASTM D3575 and ASTM D2221, define methods for conducting compressive creep tests on foam materials, with test durations extending up to 1000 hours. Accelerated methods such as Time Temperature Superposition (TTS) and the Stepped Isostress Method (SSM) have been explored for …

Understanding Policy Transfer Under Decomposition And Coordination: Sequential Reinforcement Learning With Relaxation-Based Feasibility Control, Aannand Lal

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This thesis investigates how decomposition and coordination (D&C) choices influence exploration, learning, and transfer in reinforcement learning (RL) based design frameworks. A unified methodology is developed to evaluate generality under decomposition and to demonstrate sequential coordination on a representative physical task. The generality study holds the underlying physics constant while varying problem presentation - specifically scalarization weights, objective orientations, and feasibility handling. A train-evaluate matrix is constructed in which each trained policy is assessed across all alternative decompositions. Set-based diagnostics quantify generality through exact-match identity, Jaccard similarity of distinct feasible states, total feasible coverage, and Pareto-front quality. Results show that …

Multi-Modal Data-Efficient Learning For 3d Machine Vision, Zhimin Chen

All Dissertations

The rapid progress of 3D computer vision has enabled a wide range of applications in autonomous driving, robotics, and augmented reality. Despite this growth, training robust 3D perception models remains challenging due to limited labeled data, the complexity of integrating multiple modalities, and the inherently imbalanced and long-tailed nature of 3D datasets. This dissertation addresses these challenges by proposing data-efficient, multi-modal learning frameworks that improve the accuracy, generalization, and scalability of 3D scene understanding.

In the semi-supervised setting, this work presents novel approaches that combine limited annotations with large amounts of unlabeled data to enhance 3D object classification and retrieval. …

Synthesis And Characterization Of Chemically Recyclable Polypropylene-Based Covalent Adaptable Networks, Andrii Tiiara

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Polyolefins (POs) are inexpensive engineering materials with excellent physical and mechanical properties, accounting for nearly 60% of all thermoplastics. However, large-scale recycling remains limited, with only ~15% undergoing mechanical recovery. This dissertation addresses this challenge by fragmenting and functionalizing polypropylene (PP) chains to generate macromonomers and employing them, along with industrial reactive PP macromonomers, to synthesize, depolymerize, and repolymerize chemically recyclable polypropylene-based polyolefins (CR-POs). These CR-POs incorporate ester linkages that form covalent adaptable networks (CANs), maintaining a gel fraction of ~70% while remaining melt-reprocessable via extrusion and compression molding.

First, the fragmentation of PP is investigated by microwave irradiation. Microwave …

Purifying Circular Rna Therapeutics, Karen Guillen-Cuevas

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Circular RNA (circRNA) has emerged as a promising therapeutic modality due to its enhanced stability and resistance to exonuclease degradation compared with linear mRNA. However, its stability and functionality depend strongly on achieving high purity, and current methods such as size-exclusion chromatography suffer from peak overlap, low yields, and poor scalability. This dissertation addresses these limitations by developing ultrafiltration-based strategies to purify circRNA directly from in vitro transcription (IVT) and self-splicing (circularization) reactions. First, the feasibility of ultrafiltration was demonstrated using polyethersulfone membranes, where sieving coefficients and critical flux values of circRNA, precursor RNA, and nicked RNA were measured to …

End-To-End Direct Current For Standalone Power Network, Eyad Ahmad Aldarsi

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The primary issue that faces the humanity is climate change and because of that greenhouse gases (GHGs) emissions are rising. The consequences of this issue have emphasized the necessity for replacing the dominant method of electricity generation, which mostly utilizes fossil fuels, to be centered on access to all, green, low-cost, and renewable sources of energy. Currently, photovoltaics (PV) and wind turbines are the two technologies so far that can convert the source of renewable energy, which is produced by sun irradiance and wind respectively, into large-scale electric power that can be distributed into the electricity grid. The work in …

Robust Data-Driven Predictive Control Of Nonlinear Systems Under Modeling Uncertainty, Pegah Ghafghanbari

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Data-driven predictive control enables designing controllers directly from data, making it attractive for complex systems with hard-to-model dynamics. However, practical deployment is challenged by modeling inaccuracies and changing operating conditions. This dissertation develops predictive control frameworks that incorporate robustness and adaptability to address these issues in uncertain nonlinear systems.

The first part employs the Linear Parameter-Varying (LPV) framework, which represents nonlinear dynamics through simple linear form representation. To characterize the plant-model-mismatch often caused by limited data and numerical calculations, Bayesian Neural Networks (BNNs) are used, and their uncertainty estimates are integrated into two robust control approaches. The first is a …

Surface Reaction And Transportation Of Radium-226 In Marine Systems, Jiusi Wang

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Historical uses of radium (Ra)-containing self-luminous paint, such as on gauges and dials in naval ships, have led to the potential for such paint, and thus Ra, to be released into the marine environment. Radium-226 (²²⁶Ra) behavior in marine systems is not fully described in the literature, presenting a knowledge gap in the process of evaluating potential ecological impact of Ra in marine systems. This study explores various mechanisms contributing to Ra environmental transport in marine systems on a laboratory scale, including leaching, sorption, and diffusion. ²²⁶Ra leaching from watch hand dials containing radioactive luminous paint is …

Advancing Life Cycle Assessment Of Mass Timber: Environmental Performance, Circular Design And End-Of-Life Strategies, Muzan Williams Ijeoma

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Mass timber has emerged as a leading candidate for low-carbon construction, offering the dual benefits of reduced embodied emissions and biogenic carbon storage. Yet, fully realizing its sustainability potential requires a comprehensive and context-specific understanding of its environmental performance across the entire life cycle, from raw material production to building operation and beyond end-of-life (EoL). This dissertation advances life cycle assessment (LCA) practices for mass timber by addressing critical challenges across multiple phases of its life cycle. This dissertation is comprised of three published papers, and two submitted manuscripts. First, I conducted a critical review and meta-analysis of mass …

Reverse (Bio)Engineering: A Machine Learning Approach To Optimize Baseball Pitcher Health And Performance, Robert C. Moore

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Ball tracking systems are becoming ubiquitous in sport, creating an unprecedented opportunity for big data applications to optimize human health and performance. These applications are especially common in baseball, a sport known for analyzing ball flight data to quantify performance. Analysts routinely use ball flight data to identify the attributes of top performing pitchers, finding that the best pitchers throw with optimal combinations of release speed and spin to precise locations. However, for certain pitchers, the throwing motion required to produce optimal ball flight places exceedingly high biomechanical load on the elbow, and consequently injury rates continue to rise. This …

Hybrid Learning For Rough Terrain Navigation Of Actively Articulated Wheeled Vehicles, Dhruv Mehta

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Conventional wheeled ground vehicles have been used for rough terrain navigation in the recent years. They consist of a chassis connected to wheels through passive, semi-active, or active suspension systems. However, their fixed configurations limit mobility and maneuverability, constraining their ability to autonomously navigate diverse and rough terrains. Autonomous Ground Vehicles (AGVs) face significant challenges in this regard, including varying terrain roughness, soil hardness, and obstacle crossing.

To address these limitations, Actively Articulated Wheeled Vehicle (AAWV) architectures have recently emerged, offering real-time geometric adaptability. AAWVs have chassis and wheels connected via articulated serial or parallel linkages. However, increased articulation introduces …

Data-Driven Discovery Of Finite-Dimensional Koopman Operator For Modeling And Control Of Uncrewed Ground Vehicles, Ajinkya Joglekar

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This dissertation advances data-driven modeling and adaptive control techniques for Uncrewed Ground Vehicles (UGVs), with a focus on autonomy in mission-critical and safety sensitive environments. UGVs are deployed across a wide spectrum of domains, from structured manufacturing shop floors to unstructured off-road terrains, including planetary exploration, precision agriculture, and disaster response. These platforms, operating in dull, dirty, and dangerous conditions, demand autonomy that is both adaptable and robust. While traditional model-based control methods offer interpretability and robustness, they struggle with unmodeled dynamics, parameter variations, and integration of high-dimensional sensing. Conversely, modern machine learning approaches can directly exploit sensory data but …

Hydrodynamics Of Perforated Heave Plates, Muhammad Usman

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Ocean waves are a clean and renewable energy source that can help reduce dependence on fossil fuels and combat climate change. To capture this energy, researchers have developed devices known as wave energy converters (WECs). One common type, called a two-body point absorber WEC, uses a buoy floating on the ocean surface connected to a submerged reaction plate, known as the heave plate, which lies underwater. The relative up-and-down motion between the buoy and the heave plate, driven by ocean waves, generates usable power via a power take-off (PTO) system. Traditionally, these submerged heave plates are solid structures. However, this …

Opposed-Piston Two Stroke Engine As A High Power Density Solution In Heavy Duty Applications: An Experimental Evaluation With Diesel And Ethanol, Ankur Bhatt

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With an increasing demand to reduce greenhouse gas (GHG) emissions, the conventional powertrain technology is at a saturation point. There is reinvigorated research interest in alternative powertrain designs that offer potentially higher efficiencies and lower engine-out emissions compared to conventional powertrains. The opposed piston two-stroke (OP2S) engine is one such alternative engine architecture that has demonstrated a reduction in engine-out emissions and increased efficiency compared to conventional four-stroke diesel engines. Like any two-stroke engine, the scavenging process and the composition of the internal residuals are predominantly governed by the pressure differential between the intake and the exhaust ports. Without dedicated …