Digital Commons Network^™

Accessible Real-Time Eye-Gaze Tracking For Neurocognitive Health Assessments, A Multimodal Web-Based Approach, Daniel C. Tisdale

Master's Theses

We introduce a novel integration of real-time, predictive eye-gaze tracking models into a multimodal dialogue system tailored for remote health assessments. This system is designed to be highly accessible requiring only a conventional webcam for video input along with minimal cursor interaction and utilizes engaging gaze-based tasks that can be performed directly in a web browser. We have crafted dynamic subsystems that capture high-quality data efficiently and maintain quality through instances of user attrition and incomplete calls. Additionally, these subsystems are designed with the foresight to allow for future re-analysis using improved predictive models, as well as enable the creation …

Modeling The Effectiveness Of Bioremediation On Methyl Tertiary-Butyl Ether In Groundwater, Logan Bundy

Master's Theses

Methyl tertiary-butyl ether (MTBE) and its degraded form tertiary-butyl alcohol (TBA) are both known carcinogens that have contaminated groundwater aquifers across the United States. MTBE is a synthesized compound, once widely used as an additive in gasoline to increase oxygenation. Because of its popularity, MTBE was released into the environment primarily through fuel combustion and leaking underground storage tanks. These two compounds are known to be recalcitrant to most conventional physico-chemical treatment methods. Previous studies have suggested that bioremediation is effective at degrading MTBE and TBA in contaminated groundwater. Bioremediation involves the injection of oxygen, nutrients, and pre-adapted bacterial cultures …

Generative Data Augmentation: Using Dcgan To Expand Training Datasets For Chest X-Ray Pneumonia Detection, Ryan D. Maier

Master's Theses

Recent advancements in computer vision have demonstrated remarkable success in image classification tasks, particularly when provided with an ample supply of accurately labeled images for training. These techniques have also exhibited significant potential in revolutionizing computer-aided medical diagnosis by enabling the segmentation and classification of medical images, leveraging Convolutional Neural Networks (CNNs) and similar models. However, the integration of such technologies into clinical practice faces notable challenges. Chief among these is the obstacle of acquiring high-quality medical imaging data for training purposes. Patient privacy concerns often hinder researchers from accessing large datasets, while less common medical conditions pose additional hurdles …

Assessment Of Caloric And Micronutrient Intakes In Female Collegiate Student Athletes, Rachel L. Victor

Master's Theses

Nutrition can play a key role in athletic performance. Optimal nutrition can help athletes maintain their overall health and well-being and can contribute to training adaptations, recovery, performance, and injury prevention. Many studies focus on the intakes and importance of macronutrients in athletic performance. However, micronutrient intakes may also play important roles. Therefore, the purpose of this study was to assess the calorie and selected micronutrient intakes of female collegiate student-athletes across a variety of sports. The participants were instructed to complete 3-day food records which were analyzed and compared to their individual nutrition needs. Results of this study indicated …

Hydrologic Response Of Meadow Restoration Following The Removal Of Encroached Conifers, Oriana Ramirez

Master's Theses

Meadows are important within forest ecosystems because they provide diverse species habitats, facilitate water cycling, help with sediment capture, aid in carbon sequestration, and create natural fire breaks in forested regions. However, fire suppression, poor grazing practices, and climate change have accelerated the encroachment of conifers into historical meadow habitat. This has led to an extensive loss of meadow habitat within the Sierra Nevada and Cascade Mountain Ranges. Therefore, the purpose of this study is to quantify changes in percent soil moisture and groundwater levels following the removal of encroached lodgepole pine (Pinus contorta) in a historic meadow habitat …

Emerging Diseases, Abiotic Disorders, And Macrophomina Root Rot Management Of California Strawberry, Cooper Calvin

Master's Theses

Strawberry is an economically important crop in California, with an estimated value of $2.68 billion in 2023. In California strawberry production, mitigation of low plant health and yield often focuses on major soilborne pathogens, while the contribution of minor pathogens and abiotic disorders to production shortcomings are often overlooked. The objectives of the first project in this thesis are to determine the pathogenicity of multiple minor pathogens and quantify other biotic and abiotic factors that can reduce plant health such as viruses and soil salinity. Two pathogens of the black root rot complex, Pythium spp. and Rhizoctonia spp. as well …

Red Raspberries Attenuate Blood Glucose Spike Of A High Glycemic Load Breakfast Cereal, Dante J. Martin

Master's Theses

Blood glucose (BG) spikes increase chronic disease risk in those with and without diabetes. The fiber and phytonutrient content of fruit, such as raspberries has the potential to attenuate the BG spike of a high glycemic load (HGL) meal. We examined the effect of red raspberries (RRs) on the BG spike when added to a HGL meal. In this randomized cross-over trial, 16 university students were given breakfast cereal and almond milk (control), the control breakfast with 140g added RRs, and the control breakfast with sugar equivalent to the sugar content of the RRs (50% sugar increase from control). Meals …

Non-Linear Modeling Of Hysteresis In Piezoelectric Actuated Cantilever Beam Using The Bouc-Wen Model, Andrew Donald Maas

Master's Theses

Piezoelectric actuators frequently exhibit a time-dependent behavioral phenomenon known as hysteresis, resulting in a lag in the deformation of the actuator compared to linear models. The presence of hysteresis complicates control systems involving piezoelectric actuators. However, traditional modeling methods for piezoelectric actuated smart structures often treat the piezoelectric patches as linear actuators without considering hysteresis, leading to suboptimal controller performance.

This thesis aims to establish a comprehensive model by integrating the Euler-Bernoulli beam bending model with the hysteresis dynamics induced by two opposing piezoelectric patches attached to a beam. A model expansion method is employed to transform the partial differential …

Providing Cadence Feedback In Real-Time To Guide Cardiovascular Workouts, Levi O. Rash

Master's Theses

Cardiovascular workouts offer numerous health benefits, yet beginners often find it challenging to initiate them. Existing wearable technologies, although providing valuable feedback such as heart rate zones, often disrupt the workout flow and distract users due to the need for interaction with the wearable display. In response, we propose an alternative feedback mechanism: cadence, measured in steps per minute. This feedback mechanism uses multiplicative control to produce the correct cadence for the user’s target heart rate (HR). To model the HR and cadence relationship, a first-order system was used. The prototype implementation of this system was completed in Arduino, using …

The Effect Of Probiotic Supplementation On Serum Metabolite Concentrations In Young Holstein Heifers, Emily G. Meissner

Master's Theses

The objective of this trial was to evaluate the effect of a multi-strain probiotic on serum concentrations of selected metabolites in young calves. Holstein heifers (n = 112) from a commercial dairy were enrolled within 48 h of birth and placed into individual hutches. Calves were weaned at 60 d of age and remained in their hutches until 90 d of age, when they were moved to group housing. Calves were placed into 2 treatment groups: 1) control and 2) B. subtilis, B. lichenformis, L. animalis, and P. freudenreichii probiotic (Bovamine Dairy Plus, Chr. Hansen, Milwaukee, WI). Control calves received …

Anomaly Detection In Heterogeneous Iot Systems: Leveraging Symbolic Encoding Of Performance Metrics For Anomaly Classification, Maanav Patel

Master's Theses

Anomaly detection in Internet of Things (IoT) systems has become an increasingly popular field of research as the number of IoT devices proliferate year over year. Recent research often relies on machine learning algorithms to classify sensor readings directly. However, this approach leads to solutions being non-portable and unable to be applied to varying IoT platform infrastructure, as they are trained with sensor data specific to one configuration. Moreover, sensors generate varying amounts of non-standard data which complicates model training and limits generalization. This research focuses on addressing these problems in three ways a) the creation of an IoT Testbed …

Semantic Structuring Of Digital Documents: Knowledge Graph Generation And Evaluation, Erik E. Luu

Master's Theses

In the era of total digitization of documents, navigating vast and heterogeneous data landscapes presents significant challenges for effective information retrieval, both for humans and digital agents. Traditional methods of knowledge organization often struggle to keep pace with evolving user demands, resulting in suboptimal outcomes such as information overload and disorganized data. This thesis presents a case study on a pipeline that leverages principles from cognitive science, graph theory, and semantic computing to generate semantically organized knowledge graphs. By evaluating a combination of different models, methodologies, and algorithms, the pipeline aims to enhance the organization and retrieval of digital documents. …

Effective And Sustainable Strategies For Federally Qualified Health Centers To Engage Young Adults, Olivia Mcnulty

Master's Theses

Federally qualified health centers (FQHCs) are instrumental in providing top tier healthcare and other resources to underserved populations. Whether they administer services in house or refer patients to other providers, FQHCs aim to provide comprehensive primary and preventative care services to people of all ages. They offer a range of services, from doctor and dental appointments to mental health and substance abuse counseling, regardless of a patient’s insurance status. To receive funding, FQHCs must follow the regulations and quality standards set forth by groups like the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) and the Health Resources and Services …

Deciphering The Contribution Of Microglia To Neurodegeneration In Friedreich's Ataxia, Sydney N. Gillette

Master's Theses

Friedreich's ataxia (FRDA) is the most prevalent inherited ataxia, affecting one in every 50,000 individuals in the United States. This hereditary condition is caused by an abnormal GAA trinucleotide repeat expansion within the first intron of the frataxin gene resulting in decreased levels of the frataxin protein (FXN). Insufficient cellular frataxin levels results in iron accumulation, increased reactive oxygen species production and mitochondrial dysfunction. Tissues most heavily impacted are those most dependent on oxidative phosphorylation as an energy source and include the nervous system and muscle tissue. This is evident in the clinical phenotype which includes muscle weakness, ataxia, neurodegeneration …

Pain Points: Cluster Analysis In Chronic Pain Networks, Iris W. Ho

Master's Theses

Chronic pain is a pervasive health issue, affecting a significant portion of the population and posing complex challenges due to its diverse etiology and individualized impact. To address this complexity, there is a growing interest in grouping chronic pain patients based on their unique treatment needs. While various methodologies for patient grouping have emerged, leveraging graph-based approaches to produce and evaluate such groupings remains largely unexplored. Recent studies have shown promise in integrating knowledge graphs into exploring patient similarity across different biological domains, indicating potential avenues for research. Additionally, there is a growing interest in investigating patient similarity networks, highlighting …

An Analysis Of Indoor Air Quality At Cal Poly For Sensor Design, Isabella M. Santi

Master's Theses

Prior research has shown that indoor air quality (IAQ) impacts cognitive performance. At Cal Poly, many older buildings are unable to maintain appropriate IAQ because of their outdated ventilation systems and the increasing number of students in the rooms. This work analyzes the IAQ of different buildings at Cal Poly, with a focus on Building 20. Carbon dioxide, temperature, and relative humidity inside classrooms are collected using an integrated circuit sensor and a microcontroller. A total of 38 hours of data was collected, with 22 of those hours in Building 20 specifically. We find that unlike temperature and relative humidity, …

Unraveling The History Of Deforestation In The Amazon Rainforest With Statistical Modeling, Ryan Destefano

Master's Theses

The Amazon rainforest, a vital ecosystem of immense biodiversity and global climate significance, faces the ongoing threat of deforestation driven by agricultural expansion. This thesis employs remote sensing techniques, focusing on the Enhanced Vegetation Index (EVI) derived from Landsat satellite imagery, to track land cover dynamics within the Amazon. The study examines historical land cover changes in current plantations in Peru and Brazil, regions where the exact timing of deforestation is uncertain. By analyzing EVI measurements dating back to 1984, inflection points indicative of deforestation events preceding plantation establishment are identified. Statistical modeling techniques, including spline fitting to analyze time …

Exploring Gender Disparities In Collaboration Networks: An Analysis Of H-Indices And Collaborator Proximity, Andrew R. Estrada

Master's Theses

Research is crucial for expanding the boundaries of what is known, driving innovation, and solving problems faced by communities. It is carried out across all sectors of society by all matter of institutions. Academic research is one such sector that contributes to a plethora of disciplines. Research often compels collaboration among researchers, and as with any team, the dynamics and outcomes are affected by the individuals who contribute to the research. For instance, researchers can be from different institutions; therefore research teams can differ in collaboration distance -- the geographic distance between the organizations of authors. In a similar vein, …

Identification Of Downy Mildew Resistance In Wild Arugula And Evaluation Of Downy Mildew Causing Pathogens And Management Practices, Reilly B. Blair

Master's Theses

Downy mildew has been a potentially devastating constraint to crop production within the Brassicaceae family worldwide (CABI, 2022) and on the Central Coast of California (Smukler, et al, 2008; Koike, et al. 2007). Downy mildew is a foliar disease, caused by the pathogens in the Hyaloperonospora genus on plants within the Brassicaceae family (Goker, et al, 2009). Downy mildew is a disease that is common in region of the world with Coastal climates that provide humidity and moderate temperatures (Sarahan, et al, 2017). Crops within the Brassicaceae family maintain a predominant role in agricultural systems worldwide (Cartea, et al, 2011) …

A Study On Privacy Over Security And Privacy Enhancing Networks, Everett Lee Conway

Master's Theses

With rapid developments in communication technologies and awareness of security and privacy risks online, Security and Privacy Enhancing Networks (SPENs) have become increasingly popular. Especially during the COVID-19 pandemic, workplaces encouraged employees to take additional security measures, such as VPNs. In this work, we conduct a comprehensive study on website fingerprinting attacks. A comprehensive system model and threat model based on two types of SPENs (Virtual Private Networks and Tor Networks) are presented. Moreover, we demonstrate a website fingerprinting attack by ethically collecting website fetch data and analyzing the collected data using five different machine learning classification models including k …

Design Of A Dynamic, Reconfigurable, Self-Balancing Battery Pack, Alexander Hallett Neiman

Master's Theses

This thesis details the design and testing of a reconfigurable battery array. Reconfigurable battery arrays, specifically for mobile applications, have the potential to reduce or eliminate use of auxiliary charging, balancing, and inverter systems. Design work included a bidirectional solid state switch and a cell-to-cell bidirectional current-limiting power converter. While the overall efficiency, size, and cost of the battery pack was not competitive with existing options, it demonstrated cell-to-cell balancing and native four-level square wave AC inverter output with an array of only two cells. This demonstrates viability of the concept as well as reveals important requirements and safety features …

The Effect Of Atomic Oxygen On Additively Manufactured Materials, Ryan Grogan

Master's Theses

Additive manufacturing (AM) is a rapidly developing manufacturing method utilized in fields such as the aerospace industry. In-space AM is a technology of interest for the future of spaceflight, including on-orbit manufacturing. However, AM materials are subject to defects that may impact their performance in space-based applications. How these defects change the material’s reaction to the space environment, specifically atomic oxygen (AO), has only recently been explored. AO is a highly corrosive, dominant constituent in low Earth orbit that causes continuous erosion of spacecraft surfaces. The effect of AO on various AM materials is investigated in this thesis. Stainless steel, …

Understanding Parasocial Relationships And The Mental Health Impact, Leslee Lynae Bennett

Master's Theses

Parasocial relationships have recently become a topic of discussion in our society. This is because individuals are still looking for something to connect with after the COVID-19 pandemic. These relationships originally were more common among young people, but due to the constant usage of media, individuals have become more attached to popularity which results in an unrealistic online connection. Parasocial relationships are both a fascination and a danger due to the mental connections an individual makes within themselves. This research is a qualitative study of previous research done on parasocial relationships. Topics discussed in this thesis will cover multiple facets …

Synthesis Of Geopolymer Using Coal Fly Ash And Corn Stover, Anu Paneru

Master's Theses

The development of each nation is dependent on its infrastructure, and nations are competing with others in infrastructure, especially in the construction of roadways, since they play a vital role in the economic and social development of the nation. The conventional materials used for road construction are cement and asphalt, which pose significant environmental challenges. This thesis explores the potential of fly ash (FA) and corn stover (CS) in synthesizing geopolymer, as an alternative material for the construction of roads. The study examines the impact of FA and CS percentages and the particle sizes of CS on the compressive strength, …

Barriers To Gluten-Free Diet Adherence And How They Relate To Quality Of Life And Self-Efficacy In College Students With Celiac Disease, Caitlin Elizabeth Wall

Master's Theses

Celiac disease (CD) is a chronic, autoimmune disorder with an increasing global prevalence. As the only current treatment is a strict gluten-free diet (GFD), adherence is imperative to maintain optimal health in individuals with the disease. There are many potential barriers to GFD adherence, including social, mental, and financial difficulties. College also presents a unique set of challenges for students with CD that may not be experienced by those without the disease. The purpose of this study was to determine the potential barriers to GFD adherence experienced by college students with celiac disease in the United States. This study also …

Effect Of Sex On The Accumulation Of Hepatic Mercury In Mallards Wintering In Louisiana, Latorya E. Mason

Master's Theses

The increase in mercury production through anthropogenic activities has led to a global crisis of mercury pollution that poses a significant threat to the health of both humans and wildlife. Aquatic ecosystems are especially at risk due to the creation of methylmercury, a toxic form of mercury, by sulfate-reducing bacteria in anoxic sediments and soils. Methylmercury enters the food chain where it bioaccumulates in individual organisms and then biomagnified with increasing trophic level. Aquatic birds are useful bioindicators of many pollutants, including mercury, due to their abundance and position in the food chain. Previous studies have primarily focused on mercury …

Shaping Of News Values And Frames During War: A Content Analysis Of Israeli And Palestinian Short-Form Video, Madison K. Remrey

Master's Theses

This research looks at the use of short-form video as it pertains to wartime journalism. Specifically, Instagram reels posted by both Palestinian and Israeli journalists are assessed for news values (victim, perpetrator, horse race) and news frames (straight news, conjecture, human interest). Much research has been done on news reporting and even news reporting particularly as it pertains to war. However, with recent growth of short-form video and the use of such to report on war, the landscape of digital warfare is changing. This research aims to assess how short-form video is used to report on Israel and Palestine, two …

What The Stork Brought: Endogenous Fertility Preferences, Lucas Fortier Borden

Master's Theses

Where most existing literature on fertility preferences has described how fertility preferences shape outcomes, this paper provides insight into how the sex of a recent birth affects a mother’s fertility preferences. Utilizing data from the Demographic Health Survey from 1985-2020 in 81 countries containing 309,238 mothers who gave birth in the past 12 months and who have equal to or fewer than three children, I employ OLS with two-way fixed effects as my primary specification, examining the effects of the plausibly exogenous sex of a recent birth on sibship sex composition preferences. Results show that a recent daughter birth increases …

Does Trust Influence Being Generous? An Empirical Study Across Five Countries, Andrew Hall

Master's Theses

This study examines whether social trust, a key aspect of social capital, influences individual generosity behaviors. Previous research has explored the relationship between social capital and philanthropic actions, but comprehensive analyses remain sparse. To address this gap, we employed a dictator game together with trust-related survey questions, collecting data from participants across five countries globally. We categorized trust into four distinct areas: social trust, ingroup trust, outgroup trust, and general trust. Similarly, we divided our dependent variable, generosity, into two types: costly generous and costless generous behaviors. Our findings were mixed and varied by location. Overall, general trust positively influenced …

“Bad Hombres”: Trump Era Politics And Media In Shaping The Perceptions Of The Mexican Diaspora In The United States, Angelica Soria

Master's Theses

My research delves into the anti-Mexican immigrant rhetoric spread throughout the United States under Donald Trump’s presidency by himself, mainstream media news outlet Fox News, and the U.S. government. Furthermore, examining the social identity of ethnic Mexicans in the United States in response to and as a consequence of the negative rhetoric. This thesis analyzes discourse including the harmful rhetoric and its impact on policy formulation, public perception, and the lived experiences of Mexican immigrants and ethnic Mexican communities. By looking at existing discourse, this research provides a critical discourse analysis of political speeches, media coverage, and ethnic Mexican testimonios. …