Engineering Commons^™

Fleet Algorithm Design For Pooled Rideshare: Integrating Human Factors, Simulation, And Optimization, Joseph Paul

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This dissertation explores the study the integration of human factors modeling and rideshare fleet control algorithms. Pooled rideshare is a unique transportation mode offering that allows riders increased flexibility and accessibility over public transportation, and decreased cost relative to personal vehicles or traditional rideshare. Additionally, relative to personal vehicles, pooled rideshare offers reduced costs and options for those with difficulty obtaining transportation. Prior research in the space typically focused on modeling human behavior, or optimizing system performance, but a lack of integration of the concepts leads to unrealistic or underutilized outcomes. To tackle this problem, novel rideshare assignment, and repositioning …

Self-Poled P(Vdf-Trfe) Based Composites For Energy Harvesting And Wearable Sensor Applications, Lavanya Muthusamy

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The growing demand for flexible, low-power, and self-powered wearable electronic systems has accelerated research interest in polymer-based sensors and energy harvesting technologies. Among piezoelectric polymer materials, Poly(vinylidene fluoride-trifluoro ethylene) [P(VDF-TrFE)], over the years, has garnered significant attention due to its unique piezoelectric properties, high dielectric constant, mechanical flexibility, thermal stability, chemical resistance, biocompatibility and compatibility with scalable fabrication processes. Despite its advantages, conventional P(VDF-TrFE)-based devices often require external poling and face limitations in integration with low-cost, flexible substrates. To overcome these limitations, this research study explores the nanofiller approach, along with facile fabrication processes, and structural design strategies aimed at …

Data-Driven Koopman Theory For Transient Stability And Safety Analysis Of Power Systems With Renewable Penetration, Bhagyashree Umathe

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This dissertation presents a novel approach to analyzing and controlling nonlinear systems using the Koopman operator framework and data-driven methods. Nonlinear power systems, characterized by complex behaviors and sensitivity to initial conditions, pose significant challenges for stability and safety assessment, especially during transient events.

The first part of this work focuses on reachability analysis using the spectral properties of the Koopman operator. By leveraging eigenfunctions extracted from sampled trajectory data, the approach computes forward and backward reachable sets efficiently, even in high-dimensional nonlinear systems, without requiring dense state-space sampling. This method is validated through numerical examples, demonstrating its ability to …

Impact Of Cysteine And Tyrosine Dipeptides On Cho Cell Performance In A Perfusion Mimic, Corrin L. Pruitt

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Perfusion cell cultures typically achieve higher cell densities and generate higher volumetric productivities than fed-batch cultures due to continuous nutrient supply and spent media removal. Despite these advantages, perfusion cell cultures remain underutilized for licensed product manufacturing, primarily due to the lack of small-scale perfusion models for high-throughput process development and the complexities involved in media formulation capable of supporting high cell densities during long-term continuous operation. To avoid nutrient limitation at high cell densities, current perfusion processes rely on using higher perfusion rates, which results in significant media wastage and downstream product dilution. Therefore, there has been an effort …

Decision Field Theory For Human-Multi-Robot Collaboration: Human-Centric Decision-Making For Multi-Robot Systems, Ryan Mbagna Nanko

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At first glance, choosing between an apple and an orange appears to be a straightforward matter of personal taste; however, this seemingly simple preference opens a window into the multifaceted world of decision-making, revealing the complex interplay of cognitive processes, psychological, and behavioral-economic principles that guide our choices \cite{bandyopadhyayRoleAffectDecision2013}. By unpacking these nuanced perspectives, we uncover insights that can drive more effective human-robot interaction and collaboration.

Modeling human cognition requires understanding the evolution of choice utility and the influence of emotions. Decision Field Theory (DFT) stands out by capturing the fluctuating nature in human preferences over time, explaining why choices …

Wires, Roads, And Real-World Challenges: An Interdisciplinary Case Study Bridging Roadway And Electric Utility Design, Juliann A. Lloyd

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Electric utilities are a foundational component of modern society and depend heavily on civil engineers for planning, design, construction, and maintenance. However, educational content related to this industry is often underrepresented in civil engineering programs. To bridge this gap, a case study activity was implemented in two transportation engineering courses at Clemson University. The case study introduced students to the integration between electric utility infrastructure and roadway design by simulating a realistic and common conflict scenario faced by Departments of Transportation (DOTs) nationwide.

Students were placed in interdisciplinary teams, with each member assigned a specialized role such as Land Agent, …

Advancing Multi-Physics Modeling For Microwave Heating: Application In Micro-Reactor Design And Optimization, Raghav Adhikari

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Microreactors are a type of small-scale chemical reactors for achieving reduced volume, improved product selectivity and higher reaction rate. It allows precise temperature control, which is crucial for sensitive chemical processes. Microreactors can be employed as key components of conducting small-scale reactions with improved reactor configuration and process efficiency. It is important to identify a localized and precise heating mechanism to trigger and control the corresponding chemical reactions.

In fact, microwave heating has gathered significant attention in recent years due to its ability to deliver efficient, rapid, and localized heating, which can accelerate reaction rates and enhances the reaction selectivity. …

Optimizing Park Locations While Considering Resident Behavior, Lu Liu

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Urban parks and green-spaces significantly enhance community well-being by improving physical health, mental wellness, and environmental quality. Given these extensive benefits, ensuring fair and widespread access to urban parks represents a critical priority in urban planning. Despite the advantages of parks, optimizing their location poses unique and complex challenges distinct from traditional facility location problems, such as those involving emergency services or schools. The core distinction arises from the decentralized nature of residents’ park selection behaviors. Unlike centralized allocations typically managed by public administrators, park usage decisions are driven by individual preferences and behaviors. This decentralized decision-making introduces two additional …

Visor-Zt: A Visibility, Simulation, And Operational Resilience Framework For Zero Trust Security In Ros 2, Noah Tinker

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Robotic systems are becoming more and more prevalent in modern society, with Robot Operating System 2 (ROS 2) being the dominant operating system for these implementations. Its popularity can be attributed to its design, which is purpose-built for distributed systems and asynchronous communications. However, ROS 2 security is static and therefore less capable of responding to contemporary threats and network behavior. This becomes a greater issue when considering its applications in the military and defense sectors, where security is of the highest importance. In recent years, the U.S. Department of Defense (DoD) has implemented zero trust (ZT) security based on …

Machine Learning Based Medical Ultrasound Image Classification And Grad-Cam Interpretation, Victoria C. Hemphill

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This work takes a step in creating a diagnostic tool for the classification decision process of Achilles tendinopathy using ultrasound images. An attention-based multiple instance learning model is developed to classify the images. Typically, doctors capture multiple ultrasound images of the Achilles tendon during a study to determine a complete diagnosis. Multiple instance models adopt this behavior by providing a single label for a set of instances (images). The images are grouped into ”bags” at the study level and passed into the model. The MIL model then uses its attention property to assign an importance score to each image to …

A Generalizable And Privacy-Preserving Framework For Anomaly Detection In Heterogeneous Iot Environments, Mahshid Rezakhani

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With the rapid growth of Internet of Things (IoT) devices across various sectors, detecting anomalies in such systems has become increasingly challenging. IoT environments produce diverse and evolving data streams, often lacking labeled examples, which limits the effectiveness of traditional machine learning models. These models typically require frequent retraining and struggle to adapt to new deployment conditions. This thesis proposes a flexible, privacy-aware framework for anomaly detection in multivariate time series data generated by heterogeneous IoT systems. The approach integrates a long short-term memory variational autoencoder (LSTM-VAE) with contrastive learning and adversarial adaptation, enabling the model to generalize across domains, …

Effectiveness Of Electrosynthesized Hydrogen Peroxide In Urease Inactivation For Stabilization Of Source-Separated Urine To Recover Urea, Brooke E. Covert

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The practice of separating urine at a building scale, rather than mixing with domestic wastewater to be treated at water resource recovery facilities, allows for concentrated urine to be directly treated with the aim of resource recovery. However, source separation and treatment present challenges during separation, storage, and transport. This study evaluated the use of hydrogen peroxide-producing electrochemical cells, which represent a technology that uses electricity as an input, to stabilize urine through cathodically produced peroxide to enable downstream water and nutrient recovery. The electrochemical cells have been previously shown to stabilize urine with electrochemically produced peroxide as an effective …

Grain Boundary Migration And Radiation Induced Segregation In Fe-Cr Alloys, Mohit Dhoriya

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Radiation-induced segregation (RIS) is a significant phenomenon that occurs in alloys subjected to irradiation, particularly in environments such as nuclear reactors. This thesis investigates RIS in ferritic Fe- Cr alloys through the use of Atomic Kinetic Monte Carlo (AKMC) simulations, focusing on the interaction between solute atoms and migrating grain boundaries. The study explores the influence of temperature, solute concentration, and grain boundary velocity on solute drag, a critical process driving RIS. The results show that solute migration is strongly influenced by the presence of vacancies and interstitials generated under irradiation, which are absorbed by grain boundaries and other defect …

Effect Of Cigarette Smoke Extract And Nutrient Deficiency On Energy Metabolism And Biosynthesis: An In Vitro Intervertebral Disc Explant Culture Study, Avery E. Madden

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Low back pain consistently ranks among the leading causes of disability worldwide, with degenerative changes in spinal intervertebral discs (IVDs) recognized as a key contributor. Degeneration arises from the disruption of mechanical and biological cues within the disc’s cartilaginous tissue, often exacerbated by aging or injury. In recent decades, cigarette smoking has also been identified as a significant risk factor, as IVD degeneration is more prevalent among individuals with a history of smoking. Smoke inhalation is thought to promote degeneration both directly, by exposing cells to water-soluble toxic chemicals in smoke; and indirectly, through nutrient deficiency resulting from vasoconstriction and …

Effects Of Variation In Altitude And Temperature On The Restraining Force And Internal Gauge Pressure Of Constrained Dunnage Airbags, Charles R. Weaver

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Dunnage airbags are an increasingly popular choice for securing cargo. During transit, changes in ambient temperature and pressure can cause airbags to expand generating damaging horizontal compressive forces in the trailer or container. Previous studies have developed numerical models for the behavior of Kraft paper and woven polypropylene fabric dunnage airbags under standard conditions but do not account for the behavior of airbags under varied altitudes and temperatures. This study provides empirical data on the internal gauge pressure and restraining force dynamics of 4-ply Kraft, woven polypropylene, and polyvinyl chloride airbags under simulated altitude and temperature conditions. Tensile testing characterizes …

Quantifying The Effect Of Initial Molecular Weight Distribution On The Degradation Of Linear Polyethylene At High Temperatures Using Dissipative Particle Dynamics, Cassandra L. Simpson

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Polyolefins are the primary contributors to greenhouse gas emissions and supply chain energy requirements with respect to other commodity polymers. In order to explore more efficient methods for recycling and upcycling these plastics, it is important to consider the kinetics of polymer fragments during the degradation process to more accurately reflect experimental outcomes. The molecular weight distribution of synthetic polymers is an important factor to consider when synthesizing, processing, and manufacturing industrial plastics. The breadth of this distribution, or dispersity, is determined by the ratio of the weight average molecular weight to the number average molecular weight, and is correlated …

Biological Hydrogen Process Improvements By High Temperature Simultaneous Saccharification And Fermentation, Frank W. Jeffries V

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The hyperthermophilic bacterium Thermotoga neapolitana is established as a versatile organism for fermentative hydrogen (H₂) production. Batch experiments were carried out to investigate the cell yield, product yield, and kinetic parameter values for individual media containing five carbohydrates. The highest H₂ yield of 15.56±0.31 mmol-H₂/g-carbohydrate was reported for glucose medium. H₂ yield was measured to be 14.51±0.38, 14.44±1.15, 11.88±0.84, and 11.53±0.73 mmol/g for media containing xylose, cellobiose, arabinose and xylan respectively. Acetic acid yield followed a similar trend, where the obtained values were 0.470±0.01, 0.462±0.04, 0.431±0.01, 0.409±0.03, and 0.406±0.01 g-acid/g-carbohydrate for glucose, cellobiose, xylose, …

A Study On The Propagation And Exploitation Of Structured Light In Underwater Turbulence, Jaxon P. Wiley

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The development and optimization of optical systems will play a pivotal role in the continued exploration and exploitation of the world’s underwater environments. These systems offer advantages in many sectors, and includes applications in areas such as high-speed communication, advanced sensing and imaging, and environmental characterization and monitoring. Underwater environments offer a plethora of challenges, however, and mitigating these obstacles remains an arduous task. In this work, the inherent advantages of structured light are leveraged to optimize optical system performance through non-ideal underwater conditions. Additionally, fundamental relationships between the generation of specified structured modes and their interactions with complex environments …

Multiple View Neural Regression Of A Facial Shape Model, Xiang Li

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Creating re-topologized 3D facial meshes is a critical step in high-quality facial animation pipelines, yet it remains a labor-intensive and time-consuming task. Traditional approaches typically rely on multiview stereo reconstruction and specialized photometric environments to acquire accurate geometric and reflectance data under controlled conditions. This dissertation presents work toward more efficient capture of production-ready meshes including (1) developmental aspects of VarIS, a custom-designed light sphere capable of capturing high-resolution stereo geometry and reflectance maps—including diffuse, specular, and normal components under programmable illumination; (2) a study of the effects of camera parameters on automatic 2D and 3D landmarking methods, (3) methods …

Advancing Smart And Adaptive Living Spaces Through Design And Development Of Reconfigurable Multifunctional Robot Rooms, Nithesh Kumar

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This work explores and introduces prototype hardware for a new category of robots: ‘Robot Rooms’, in an effort to refine the concept of traditional smart spaces and human-robot interaction. Unlike traditional robots that tend to be compact and exist within a space, this new category of robots is designed to be expansive: they do not exist within a space but rather shape space around them. We present several design concepts for potential robotic elements of a Robot Room. We then develop and demonstrate, at full scale, a new and novel concept: a ‘slice’ of a Robot Room. This slice changes …

Robust Online Inertia Estimation In Power Systems Using Ambient Data In The Presence Of Inverter-Based Resources, Narges Ghiasi

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The increasing penetration of Inverter-Based Resources (IBRs) in power systems has significantly altered system dynamics, reducing the system's effective rotational inertia and challenging frequency stability. Accurate online inertia estimation is essential for maintaining system reliability under these evolving conditions. This paper introduces a robust methodology for online inertia estimation using ambient data collected during normal system operation. The proposed method employs a state-space model to represent system dynamics and introduces synthetic step changes to simulate disturbances. By analyzing the frequency response and applying advanced signal processing techniques, the methodology estimates system inertia without requiring real large-scale disturbances. The approach is …

Replacement Optimization For Offshore Wind Turbine Farms, Morteza Soltani

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This dissertation is concerned with devising optimal replacement policies for offshore wind turbines with a focus on minimizing the costs associated with major component replacements and production losses due to downtime. Like their onshore counterparts, offshore wind turbines are subject to progressive degradation due to normal operations, as well as the influence of dynamic environmental conditions that influence their rate of degradation. Due to their proximity, wind farm turbines share common environmental conditions, as well as specialized maintenance resources. Their common exposure to the environment and need to share resources introduce both stochastic and economic dependence between the wind turbines. …

Advancing Life Cycle Assessment For Environmental Sustainability Of Carbon Fiber-Reinforced Polymer Composites (Cfrps)), Hao Chen

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Carbon fiber-reinforced polymer composites (CFRPs) have emerged as promising materials, particularly for lightweight applications, with the potential to reduce environmental impacts across multiple sectors, including automotive, aerospace, and renewable energy. However, fully realizing their sustainability potential requires a more comprehensive and context-specific understanding of their environmental performance throughout the entire life cycle—from raw material production to end-of-life management.

This dissertation advances life cycle assessment (LCA) practices for CFRPs by addressing key challenges across multiple phases of the CFRP life cycle. First, I conducted a critical review and meta-analysis of carbon fiber manufacturing, revealing substantial variability in reported data on energy …

Designing Self-Healable Aromatic Copolymers And Olefinic Composites, Samruddhi Yashwant Gaikwad

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Self-healing polymers capable of recovering from mechanical damage are promising materials for advanced applications, especially those involving mechanical and/or physical fatigue. In these studies, we have developed techniques to achieve autonomous self-healing in commodity Styrene/n-butyl acrylate copolymers. The mechanism of self-healing in the designed polymers involves inter-and/or intrachain non-covalent interactions between π-cloud and polar linkages of acrylic nBA in random/preferentially alternating copolymers. A combination of spectroscopic tools, thermo-mechanical analysis, and molecular dynamics (MD) simulations has been used to elucidate the mechanism of self-healing. These studies further show the incorporation of dipolar C-F groups to understand the effect of having fluorinated …

Effects Of Lossy Compression Data On Machine Learning Models, Max H. Faykus Iii

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Machine learning is a fundamental tool that is incorporated in every field across academia and other industries. Due to the large amount of data needed for training machine learning models, lossy compression plays a crucial role in storing data. Machine learning involves the use of algorithms and models to learn patterns in data. This allows the AI to make decisions without specific programming. On the other hand, compression utilizes encoding and decoding techniques to reduce the size of files. Compression is either lossy or lossless, lossy causes a loss of data while lossless preserves the data. This dissertation will explore …

Structural Design Using Conditional-Gan Fused With Property Text Information: A Case For Masonry Structures, Arash Teymori Gharah Tapeh

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Structural design, by nature, is a complex process that requires a considerable amount of time, expertise, and knowledge. In such a process, the structural designer must navigate various codal provisions to crystallize a proper and adequate design. As the role of automation continues to shape the domain of structural engineering over the past few decades, a new front leverages artificial intelligence (AI). Currently, AI acts as a "copilot," collaborating to advance workflow speed and accelerate the design process. Among all the different collaborations between humans and AI, GANs (Generative Adversarial Networks) are seen to complement human creativity by automating specific …

An Investigation Into The Impact Of Inverter Based Resources On Critical Clearing Time, Trupal Patel

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Renewable energy sources, mainly inverter-based resources (IBRs) such as solar and wind plants are being connected in large numbers to the bulk power grid in the United States and around the world. Additionally, generation using fossil fuels are being phased out, which results in the loss of rotor inertia, a key contributor to the transient stability of power systems. Therefore, the large-signal behavior of IBRs and its impact on transient stability must be studied.

This work studies this impact through the metric of critical clearing time (CCT). Impact of grid topology, generation mix and control modes of IBRs on CCT …

Bilevel Network Interdiction Models For Human Trafficking Disruption, Daniel Bruno Lopes Da Silva

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In this dissertation, we study a series of bilevel network interdiction problems motivated by applications in human trafficking disruption. First, we consider a bilevel network interdiction problem where the follower aims to maximize the amount of flow from the source node to the sink node and the leader aims to minimize the number of arcs from a critical set that have positive flow on them in the solution obtained by the follower. This problem models the situation where an anti-trafficking agent wants to minimize the number of people affected by the trafficking operations whereas the trafficker wants to maximize trafficking …

Modeling Disaster Resilience Through A Human-Centered Lens: Exposure, Vulnerability And Adaptation, Tong Liu

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The core of reframing and operationalizing disaster resilience with a human-centered lens is to incorporate concepts from socio-ecological resilience into engineering resilience to better understand the humans’ capability for disaster adaptation. Existing studies have drawn practical implications by identifying actionable thresholds for infrastructure systems under disasters, which can be easily applied by policymakers, emergency managers and municipal agencies. However, how individuals interact with, respond to, or adapt under these infrastructure thresholds remain understudied. This hinders the operationalization of disaster resilience at the human scale.

First, I examined exposure by analyzing how configuration and distribution of urban infrastructure systems, such as …

Synthesis And Characterization Of Magnetic Nanoparticles To Study Effective Magnetic Anisotropy For Biomedical And Catalytic Applications, Alexander Malaj

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This dissertation focuses on understanding how to tune the magnetic properties of nanoparticles through controlling the effective magnetic anisotropy (Keff), which is a key variable in determining a nanoparticle’s Néel relaxation time, which will dictate its magnetic behavior in various applications. In this work, magnetocrystalline anisotropy is tuned by synthesizing tri-metallic substituted ferrite (Fe3-x-yMnxCoyO4) nanoparticles with specific metallic compositions that were informed by computer simulations using density functional theory (DFT) to target magnetocrystalline anisotropy values. A drip synthesis was used to control the size and composition of the tri-metallic ferrites, which were revealed to be monodisperse and compositionally mixed by …