Digital Commons Network^™

Accelerating Relationship Discovery In Chronic Lower Back Pain Through Knowledge Graph And Ontology Enhanced Large Language Models, Damon Lin

Master's Theses

Chronic lower back pain (cLBP) is a widespread public health burden linked to anxiety, depression, and opioid addiction. Interventions aimed at treating cLBP have shown minimal improvements in pain outcomes, leading researchers to reexamine our understanding of cLBP through constructing a causal model. However, constructing causal models through Randomized Controlled Trials are often unfeasible, and relying on domain expertise requires extensive and time-consuming research, posing a serious bottleneck for designing effective treatments. To accelerate this process, we apply Knowledge Graphs, Ontologies, and Large Language Models (LLMs) to aid researchers in determining possible causal relationships. First, we demonstrate how LLMs can …

Dynamic Modeling And Simulation Of A Power Generation Steam Rankine Cycle For A Fluoride Salt-Cooled High-Temperature Reactor Nuclear Power Plant, William R. Ton

Master's Theses

Nuclear Fluoride Salt-Cooled High-Temperature Reactors (FHRs) have the potential to greatly improve nuclear technology in terms of safety and cost. By combining molten salt coolant technology from the Molten Salt Reactor (MSR) and TRISO fuel technology from the Very High Temperature Gas Reactor (VHTR), FHRs may operate at significantly lower pressures than Light Water Reactors (LWRs) and with a more robust fuel source that is excellent at containing fission products. However, as no FHR has been built, there are still many design questions to address. This thesis uses transient computer modeling and simulation to investigate how an FHR could potentially …

A Comparative Evaluation Of Feedback Strategies For Enhancing Student Software Test Suite Writing Outcomes, Ashton Alonge

Master's Theses

Background and Context

Software testing is a fundamental component of computer science education, forming the basis for students’ ability to ensure program correctness and reliability. Despite its importance, many students struggle to design test cases that effectively expose faults and achieve meaningful test coverage. Traditional instructional approaches often emphasize code coverage metrics such as line or branch coverage, but these metrics may not adequately capture the quality of student tests. Mutation analysis, which measures how well tests detect small, artificial faults (mutants) introduced into the program, offers a potentially richer measure of test effectiveness. However, little is known about how …

Real Time Markerless 3d Hand Tracking For Intuitive Robotic Arm Control, Dylan G. Featherson

Master's Theses

This thesis presents a real-time, markerless motion-capture system for intuitive control of a multi-degree-of-freedom robotic arm. Using two synchronized RGB cameras and stereo-vision triangulation, the system reconstructs the three-dimensional position of a user’s hand without the need for physical markers or wearable sensors. The reconstructed 3D coordinates are mapped directly to the end-effector position of the Quanser QArm, a four-degree-of-freedom educational manipulator. Developed entirely in Python, the system integrates stereo camera calibration, 3D hand tracking with MediaPipe, coordinate transformation, and inverse kinematics into a unified real-time control pipeline operating at approximately 200 Hz. Calibration is performed through a checkerboard-based stereo …

Generalized Detection Of Animal Behavior Using Accelerometers, Alexander J. Arrieta

Master's Theses

Animal mounted sensors are becoming increasingly used to passively monitor both domestic and wild animals. Advances in lightweight accelerometer and GPS technology have allowed many animals to be fitted with high accuracy sensors for extended periods of time. This leads to new opportunities to study animal behavior without direct observation. However, interpreting the raw data is difficult due to the high volume and missing context of the information. Machine learning techniques excel at extracting information from raw data streams and are excellent candidates for processing the sensor data. However, due to large variance in how different animals execute the same …

Predicting Newsworthiness Of California Bill Discussions, Venkata Kedarnath Chaturvedula

Master's Theses

Among various California bill hearings, it is crucial to identify which hearings are most likely to receive media coverage, as this highlights the importance of the bill and the hearing, while also underscoring its societal impact. Digital Democracy, established at Cal Poly’s Institute for Advanced Technology and Public Policy, provides users access to a distinctive dataset and information about state legislative committee hearings, hearing transcripts, assets, bill information, etc.

This thesis presents a machine learning framework for predicting whether California legislative bills are likely to receive media coverage. Drawing on a dataset of legislative ”tip sheets” provided by Digital Democracy …

Per- And Poly-Fluoroalkyl Substances Fate Across California Wastewater Treatment Plants: A Meta-Analysis Of Formation, Distribution, And Persistence, Elizabeth Reineke

Master's Theses

Per- and poly-fluoroalkyl substances (PFAS) are persistent contaminants that move through municipal and industrial wastewater systems with limited attenuation. As a result, they are increasingly detected in drinking water supplies. Despite growing regulatory concern, a systems-level understanding of PFAS behavior across multiple treatment facilities and watershed settings remains incomplete. This study compiled influent, effluent, and biosolids datasets from more than one hundred California wastewater treatment plants to evaluate PFAS occurrence, transformation, and partitioning across diverse treatment configurations. Analytical steps included calculating removal efficiencies, assessing precursor-to-product oxidation, evaluating co-contaminant correlations, and grouping facilities by process design to quantify configuration-specific fate patterns. …

Building Roads To Engagement: A Survey Of Post-Secondary Community Engagement Education In Transportation, Meghan E. Kolin

Master's Theses

Community engagement is a critical part of the urban planning process for both academics and practitioners, but transportation planning’s significant technical knowledge requirements and focus on special interest groups make such engagement difficult. As such, college- and graduate-level transportation planning programs must include significant education about public participation practices. However, little research exists regarding how community engagement is taught in these programs or how well this education prepares students for real-world practice. This research is aimed at filling this gap by answering two questions: first, how transportation-focused post-secondary programs in the United States conduct community engagement education; and second, whether …

Hallucination Techniques For Self-Supervised Synthetic Datasets For Mobile Robots, Wyatt D. Colburn

Master's Theses

Classical techniques in autonomous navigation struggle in tightly constrained spaces. Machine learning has been shown to perform better in these difficult environments but most techniques require large amounts of navigation experience for training. Using a new machine learning paradigm learning from hallucination (LfH), training data can be collected in a safe environment and not require supervision. Data is collected in real time while an agent performs a random walk in free space, supervision is not required as there are no obstacles for the robot to run into. After a random walk a post processing pipeline will hallucinate a safety corridor …

Birds In Changing Landscapes: Community Diversity And Breeding Phenology, Lindsay Peria

Master's Theses

Humans are altering the environment in varied and widespread ways. Increasing urban and agricultural development causes changes to habitat and resource availability as well as changes to the sensory environment via light and noise pollution. Climate change also causes more extreme temperature anomalies, storms, and droughts that challenge birds in a multitude of ways. In this thesis, we assessed these impacts of these changes on a local and continental scale. In the first chapter, we assessed the impact of natural, anthropic, and structural characteristics of viticultural land on both taxonomic and structural avian diversity. Loss of habitat from agriculture is …

Impacts Of Halophila Stipulacea Invasion On Organic Matter Dynamics In Thalassia Testudinum Dominated Seagrass Meadows, Puerto Rico, Jonathan D. Herald

Master's Theses

Halophila stipulacea (Forsskål & Niebuhr) is a tropical seagrass native to the Red Sea, Persian Gulf, and Indian Ocean. In 2002, invasive populations of H. stipulacea were identified in the Caribbean Sea where it now forms large meadows, displaces native seagrasses, alters invertebrate and fish communities, and potentially affects organic matter dynamics in invaded meadows. This study investigated differences in organic matter dynamics between meadows of H. stipulacea and native Thalassia testudinum within the Jobos Bay National Estuarine Research Reserve (JBNERR) on the southern coast of Puerto Rico. From March 2023-March 2024, sampling was conducted across four sites to investigate …

Effects Of Urbanization On The Population Genetics And Morphology Of The White-Footed Mouse (Peromyscus Leucopus) Across An Urban–Rural Gradient, Sydney A. Morton

Master's Theses

Urbanization alters landscapes in ways that can reshape wildlife populations by changing habitat connectivity, resource availability, and selective pressures. To investigate how urbanization influences both genetic differentiation and morphology in small mammals, I examined Peromyscus leucopus (PELE) across an urban–rural gradient in northern Georgia. Using RADseq SNP data from PELE individuals across 13 sites, I quantified pairwise genetic differentiation (F_ST) and tested how various environmental variables, including impervious surface cover, human population density, and tree canopy cover, predict genetic differentiation after accounting for geographic distance. Genetic differentiation increased with geographic distance and, after controlling for isolation by …

Topographic And Upwelling Effects On Surface Lagrangian Coherent Structures Of Cape Mendocino, Basil Martin Darby

Master's Theses

The goal of this study is to investigate fine-scale Lagrangian coherent structure (LCS) generation in a coastal upwelling setting with prominent topography using a high-resolution global-ocean circulation model (LLC4320). I examine LCS properties, spatiotemporal evolution and vertical structure, as well as possible connections to submesoscale variability and chlorophyll. The LLC4320 simulation in the Cape Mendocino region is evaluated using high-resolution satellite and other ocean observations. Additionally, this study uses a novel dynamical systems technique by relating the LCS of flow fields to the physical dynamics of the mesoscale-to-submesesoscale transition. It is found that time series of short timescale LCS yield …

Retrieval Augmented Framework For Deepfake Audio Detection, Avinash Saxena

Master's Theses

The widespread use of AI-based audio deepfakes threatens severely to undermine media integrity and public trust. Speech synthesis techniques have improved dramatically in voice conversion (VC) and text-to-speech (TTS) in recent years, making forgeries sound highly realistic, and concerns are raised about possible malevolent uses. Existing state-of-the-art techniques for identifying fake speech have proven to be effective in some cases but are still limited in application and robustness when faced with novel attacking strategies, different acoustic conditions, or alternative linguistic domains. To address some of these limitations, the current research presents a novel deepfake audio detection system based on personalized …

Digital Neuropsychology And Social Anxiety: The Effect Of Observer Presence And Personality On Stress And Cognition, Ava M. Dixon

Master's Theses

This study examined how observer presence and social anxiety influence stress and cognitive performance during neuropsychological assessments, focusing on the potential benefits of unsupervised digital testing environments. Eighty university students were randomly assigned to observed or unobserved digital neuropsychological conditions and completed assessments of social cognition and executive functioning and questionnaires of social anxiety and personality. Participants also completed measures of state anxiety and heart rate variability at baseline and after cognitive tests. The findings indicated that observation led to higher subjective anxiety, but it did not produce significant interactions with social anxiety on stress or cognitive performance. Post-hoc analyses …

An Exploration Of Image Segmentation Techniques For Real-Time Product Detection, Andrew C. Dunton

Master's Theses

Recent progress in LLMs enables advanced multimodal understanding, but their high computational cost necessitates monetization strategies like interactive advertising. While bounding boxes show promise for this concept, they can lack precision and visual appeal. Image segmentation offers a superior solution but faces a dual problem: traditional models demand scarce, costly training data, and open-vocabulary segmentation models like SAM are class-agnostic, unable to semantically identify a "consumer product" object class. In this research, we address these limitations by: 1) developing the Prompt-Guided Inpainting Framework (PGIF), which injects negative prompts to generate robustly annotated synthetic segmented product images; 2) investigating the Class-Agnostic …

Radiation Hardness Study Of Finfet And Gate-All-Around Fet Sram, Albert Lu

Master's Theses

Radiation, such as alpha particles or neutrons, is hard to control and can come from sources such as trace impurities or cosmic rays from space. These can then strike a semiconductor device, such as a Static Random Access Memory (SRAM) cell, and cause the SRAM to have its bit flipped. This bit flip is often just a temporary effect and is thus called a single event upset (SEU). Although it is temporary, a bit flip can cause severe consequences, such as affecting program functionality by causing incorrect data to be used. This is made worse in critical environments that need …

Early Visual Predictors Of Progression To Alzheimer’S Disease And Dementia With Lewy Bodies, Abril Baez

Master's Theses

We examined whether specific visual cognitive skills predict progression from Mild Cognitive Impairment (MCI) to Alzheimer’s disease (AD), or dementia with Lewy bodies (DLB). The Benson Complex Figure Task (BCFT) was used to measure visual perception and construction (copy), and visual memory (recall). National Alzheimer Coordination Center longitudinal dataset included participants who remained stable (MCI-stable; n =2630), progressed to AD (MCI-AD; n =798), or progressed to DLB (MCI-DLB; n =59). Baseline BCFT scores were entered into logistic regression models predicting diagnostic outcome. Impaired copy performance was significantly associated with MCI-DLB (B = 0.79, OR = 2.21, BCa CI [0.26, 1.36], …

A Convolutional Neural Network Approach To Breast Cancer Tumor Boundary Detection, James Leah Matlosz

Master's Theses

Breast cancer is the second most common form of cancer and often goes undetected in its initial stages due to its subtle symptoms. As the tumors grow, they become more difficult to surgically remove with clean borders. To minimize the chance of recurrence, a 2D convolutional neural network is developed in this work for delineating tumor boundaries. Specifically, the U-shaped network model is trained, validated, and tested with longitudinal MRI scans of patients diagnosed with breast cancer and undergoing neoadjuvant therapy. For training, image masks were generated as ground truths using signal enhancement ratio segmentation, thresholding, and contour detection. The …

Phylogenetic Comparative Vocal Evolution, Casper W. Buchanan

Master's Theses

Vocal learning is a trait unique to humans, bats, cetaceans, primates, and birds (Jarvis & Nottebohm, 1997; McComb & Semple, 2005; Wilbrecht & Nottebohm, 2003). Although there has been extensive research on vocal learning in songbirds, parrots are an even closer proxy to human learning, as they are social, intelligent, and lifelong learners, with some having repertoires of over 300 sounds (Benedict et al., 2022; Péron et al., 2011; Thomsen et al., 2019; Toft & Wright, 2015). Elevated vocal learning can be attributed to the need for parrots to have strong communication skills through the sharing of information over foraging, …

Towards Automated And Explainable Insider Threat Response In Electronic Health Records: A Role-Aware Machine Learning Framework, Luca Lippi Ornstil

Master's Theses

Healthcare remains a prime target for cyberattacks, with insider misuse and credential compromise posing major risks to Electronic Health Records (EHRs). This thesis introduces a role-aware, explainable anomaly detection and response framework integrated with OpenEMR to address post-authentication threats. Four models—Local Outlier Factor (LOF), Isolation Forest, Autoencoder, and Graph Neural Network (GNN)—detect behavioral deviations across temporal, device, and role-based features, with LOF serving as the primary runtime detector. A configurable policy engine maps anomaly severity to proportional actions, from email alerts to read-only restrictions or account suspension, all reversible and auditable. Evaluation on real EHR logs shows the system’s operational …

Gene Expression Of Anthocyanin Pigments In The California Native Plant Leptosiphon Parviflorus: Interactions Between Flower Color Morphology And Abiotic Stressors, Weston Gonor

Master's Theses

For plants to survive in harsh conditions imposed by abiotic stressors, they must develop mechanisms of adaptation. One of the common types of adaptation seen in plants is the production of anthocyanin pigments, which have been shown to protect plants from UV radiation, metabolic stress, and drought. In this study, we used the flower color polymorphic species Leptosiphon parviflorus to investigate the role of anthocyanin pigments in protecting plants from abiotic stress. To accomplish this, RNA samples were taken from flower, leaf and root tissue of different flower color morphs of Leptosiphon parviflorus (Polemoniaceae) grown in high magnesium and water …

Experimental Study Of Gas-Dynamic Heating In Hartmann-Sprenger Tubes For Rocket Engine Ignition, Jacob T. Huff

Master's Theses

Ignition systems for chemical rocket engines typically rely on hypergolic propellants or auxiliary electrical hardware to supply the energy required to initiate combustion. The resonance igniter is a simple and robust alternative to these conventional methods, capable of inducing autoignition of non-hypergolic propellants without an external ignition source. At the core of this concept is the Hartmann-Sprenger Tube (HST), a device in which a high-velocity jet of gas impinges on a resonance cavity. This interaction establishes self-sustaining gas oscillations within the cavity that heat the propellants to their autoignition temperature. To facilitate the development of a functional resonance igniter at …

Enhancing Non-Player Character Dialogue In Video Gages: An Evaluation Of Large Language Model-Generated Responses, Lam P. Quach

Master's Theses

As video games increasingly emphasize narrative depth and player immersion, the quality of Non-Player Character (NPC) dialogue has become crucial for creating engaging gaming experiences. This thesis investigates the potential of Large Language Models (LLMs) to generate high-quality NPC dialogue by comprehensively evaluating four state-of-the-art models: Gemma 3 27B, Mistral 7B, QWEN 2.5, and LLAMA 3.1. The study employs a mixed-methods approach, combining human evaluation (N=50 participants) with AI-based assessment across five key benchmarks: coherence, personality expression, engagement, style/tone appropriateness, and overall quality. Participants evaluated 32 dialogue samples (8 per model) generated for a fantasy game context featuring two distinct …

Sparse-Data Orbit Estimation In Low Earth Orbit Using The Markov Chain Monte Carlo Ensemble Gaussian Mixture Filter, Nicholas J. Oden

Master's Theses

The number of space objects (SOs) in low Earth orbit (LEO) continues to increase rapidly, creating challenges for the current ground-based tracking network, which cannot accommodate the projected growth in SOs. Catalog maintenance relies on frequent observations for reliable reacquisition, with Two-Line Element (TLE) sets typically generated daily to mitigate rapid error growth from poor TLE accuracy. This constraint limits the ability to track more objects with existing infrastructure. This work evaluates the Markov Chain Monte Carlo Ensemble Gaussian Mixture Filter (MCMC EnGMF), a nonlinear, non-Gaussian filter well-suited for sparse tracking scenarios where higher post-update accuracy is needed to reduce …

Building A Novel Question-Answering System Using Retrieval-Augmented Generation For The California Fair Political Practices Commission, Saanvi Dua

Master's Theses

The California Fair Political Practices Commission (FPPC) receives a high volume of inquiries via email from public officials, the general public, and other agencies, which currently requires staff to manually search through informational documents and manuals to provide timely responses. This process is both labor- and time-intensive.

To address this challenge, we design a question-answering (QA) system that drafts responses to emailed questions by retrieving relevant information from the FPPC’s manuals using a retrieval-augmented generation (RAG) framework. Although the current implementation focuses on a single manual, the system is designed to be adaptable to the broader set of FPPC documents. …

Effect Of Seasonal Variability In Methane Emissions And Iron Redox Chemistry At Terrestrial-Aquatic Interfaces, Hermes C. Ruiz

Master's Theses

Methane (CH₄) emissions at terrestrial–aquatic interfaces (TAIs) are significant contributors to the global carbon budget, yet the mechanisms driving methanogenesis remain poorly understood. Limited data exist on how seasonal variations and redox processes influence CH₄ fluxes in these dynamic ecosystems. This study addressed two questions: (1) How are CH₄ fluxes in riverine floodplains and adjacent hillslopes impacted by seasonal variations? (2) What roles do metal redox processes (e.g., iron (Fe)) play in regulating methanogenesis?

In-situ CH₄ flux and solid-phase Fe speciation were quantified in East River, CO, under flooded and drained conditions. Groundwater chemistry, gas flux, and soil physical properties …

Exploring The Moderating Effect Of Boundary Management Strategy In A Remote Work Environment, Brandon M. Vasquez

Master's Theses

Remote work has evolved significantly, especially during the COVID-19 pandemic, and continues to influence employee experiences in both positive and negative ways. Managing the separation between work and personal life is of importance. More specifically, using a boundary management strategy of segmentation may be more effective than an integration strategy because those who separate the two domains of work and family/personal life may be less prone to conflict in their lives. The present study aimed to examine the moderating effect of boundary management strategy on the relationship between remote work and job satisfaction, work-life balance, and well-being. Specifically, it was …

Attention In The Age Of Tiktok: Examining The Cognitive Impact Of Short-Form Video Consumption, Samantha Shannon Sutrisno

Master's Theses

With the rapid growth of popularity among short-form video platforms such as TikTok, media consumption has shifted toward fast-paced and highly engaging formats. This trend raises questions about the potential effects of continuous exposure to brief and repetitive audiovisual stimuli on attention. Research on short-form video’s impact on attention is limited, but prior studies suggest it may influence attention in meaningful ways. This study examined the relationship between short-form video consumption and attention among TikTok users (N = 110) by using the Attention Network Task (ANT), which measures the alerting, orienting, and executive control networks of visual attention. Participants were …

Evaluation Of The Performance Of The Traveling Wave Differential Element In Protective Relays, Niranjan Kc

Master's Theses

This thesis evaluates the dependability, security, and limitations of the traveling wave differential protection function (TW87) in modern time-domain-based protective relays, using a combination of simulations and hardware testing in a laboratory environment. Fault transients are first generated using the electromagnetic transients program model of a real, 230 kV, 65.7 km long overhead transmission line, which are then played back on real time-domain-based protective relays. Various fault scenarios are chosen to evaluate the impacts of factors such as fault inception angle, distance to fault from line terminals, fault type, fault impedance, and external faults on the relay functions’ performance. Results …