Digital Commons Network^™

No Change In Functional Ecology Or Body Size In Response To A Global Climate Event In The Late Maastrichtian Owl Creek Formation, William T. Rizza

Master's Theses

During the last 300 ka of the Maastrichtian, global temperatures increased and decreased by ~2℃, likely caused by a pulse of Deccan volcanism. The Owl Creek Type Section in Mississippi records some portion of the last 400 ka of the Late Maastrichtian. It is expected that marine invertebrates will demonstrate a taxonomic, ecological, or morphological response to rapid temperature change. I anticipate a decrease in taxonomic diversity and shell volume and an increased abundance of low activity-level species, similar to the ecological impacts observed in response to Large Igneous Province eruptions in the geologic record. Clumped isotope paleotemperature reconstruction recovers …

Implications Of Persistent Micro-Bioplastics On Biogeochemical Properties Across Soil Types, Casandra R. Leach

Master's Theses

Terrestrial microplastics are increasing in abundance and are an emerging contaminant of concern, particularly in agriculture ecosystems where plastic use and subsequent soil contamination are prevalent. Plastic film mulches make up a significant portion of the plasticulture industry and are directly linked to soil microplastic pollution where negative effects to soil biotic and abiotic functions have been observed. In response to this issue, biodegradable film mulches have been promoted as a sustainable alternative to conventional polyethylene-based mulches. These biodegradable mulches, composed of various bioplastics, are designed to be tilled back into the soil where they are expected to decompose. However, …

Hardware Control Unit For Trusted Program Verification System, Jake Owen Alt

Master's Theses

Trust in the underlying hardware is the foundational step towards trusting the correctness and integrity of a software application. However, verifying that today's extremely complex processors work exactly as intended has not been feasible, as evidenced by several recent hardware bugs. Trustworthy, formally verified processors currently forego intricate performance enhancements such as out-of-order execution, hampering them substantially versus their less secure counterparts.

The Containment Architecture with Verified Output (CAVO) system solves this problem by isolating the host system and requiring the result of each instruction to be validated by a small, trusted hardware module called the Sentry. Any transmissions to …

Understanding Teachers’ Responses To Parental Demands In The Midst Of Competing Responsibilities, Kathryn Battafarano

Master's Theses

This study builds upon a plethora of educational research and focuses specifically on middle school grade level teachers. I predominantly utilized qualitative interviews to understand how teachers respond to parental demands; these answers were supplemented by some quantitative data about their schools. The study configures information about teachers’ school environments and requirements, teachers’ interactions with parents, and how teachers deal with parental demands in relation to other demands and requirements. Effort was made to investigate how teacher experience, teaching style, and subject matter as well as school type (e.g., socio-economic makeup of the school) and school location influence parental demands …

Dynamic Maze Puzzle Navigation Using Deep Reinforcement Learning, Luisa Shu Yi Chiu

Master's Theses

The implementation of deep reinforcement learning in mobile robotics offers a great solution for the development of autonomous mobile robots to efficiently complete tasks and transport objects. Reinforcement learning continues to show impressive potential in robotics applications through self-learning and biological plausibility. Despite its advancements, challenges remain in applying these machine learning techniques in dynamic environments. This thesis explores the performance of Deep Q-Networks (DQN), using images as an input, for mobile robot navigation in dynamic maze puzzles and aims to contribute to advancements in deep reinforcement learning applications for simulated and real-life robotic systems. This project is a step …

Investigation Of Temperature, Solution Strength, And Applied Stress Effects On Cation Exchange Processes In Different Geosynthetic Clay Liner Products, Kendra Fuller

Master's Theses

An extensive laboratory test program was conducted to analyze and compare the cation exchange processes in three different varieties of sodium bentonite (Na-B) geosynthetic clay liners (GCLs) over increased conditioning durations up to 32 days and investigate the effects of temperature, solution strength, and applied stress. The goal of this test program was to establish whether the variables of temperature, solution strength, and applied stress improved or degraded the engineering properties of GCLs in laboratory testing and municipal solid waste (MSW) landfill applications. The GCLs were conditioned in liquids of increasing ionic strength, using deionized water and 2, 50, and …

History & Evolution Of Plastic Mulching Technology: An Ethnography Of California Strawberry Plasticulture, Kalea Conrad

Master's Theses

This ethnography draws on key informant interviews and participant observation to produce a case study about plastic mulching as an important industry standard in specialty crop production. It documents the historic adoption and present role of plastic mulching technology in California strawberry production and addresses the characteristics of commercial standard management that inhibit the adoption of alternative mulching practices. It complements extensive research on strawberry pathology and fumigation, breeding innovations, fertilizer and pesticide treatments, and maximization of yields to incorporate participants’ lived experiences and knowledge of mulch origins, the technology adoption process, mulch benefits and drawbacks, the state of agricultural …

Dual Base Sige Is-Hbt For Use In Biosensing Applications, Liam Stephen Hayes

Master's Theses

The proposed research is for a novel SiGe-based Ion-Sensitive Dual Hetero-junction Bipolar Transistor (IS-HBT) to be used in both trans-dermal biological sensing as well as Lab-on-Chip (LOC) applications. The end goals for the device designed are two: For one, the research done for this work will be used to substantiate the claims made by Zafar et al. [1] that an HBT-style structure is better suited for biosensing application rather than a conventional Field Effect Transistor (FET) based geometries. Secondly, it provides the final element to be integrated along with a selectivity membrane, as well as with a reverse-iontophoresis system to …

Of Geese And Grass: Investigating Impacts Of Brant Grazing On Eeelgrass, Dakota L. Osborne

Master's Theses

Grazing pressure is important in structuring plant communities, particularly in aquatic environments. Eelgrass (Zostera marina), a keystone species in estuaries across North America, is experiencing widespread population declines. As a keystone species, eelgrass provides numerous important functions, including: 1) water filtration, 2) sediment stabilization, 3) providing refuge and nursery habitat for numerous species, and 4) carbon sequestration. Benefits which could be lost if eelgrass beds continue to diminish. California has experienced some of the greatest eelgrass declines, and Morro Bay, CA experienced a 96% decrease in eelgrass from 2007 to 2017. Most studies to date have examined bottom-up …

Representation Theory Arising From Groups In Physics, Jaxon Green

Master's Theses

A representation is a group homomorphism whose image is a group of invertible matrices. Representations and their associated matrices are analyzed through well-established techniques from linear algebra. We characterize representations by a unique decomposition into irreducible representations just as we characterize the decomposition of matrices into their eigenspaces. Through the study of these representations, we uncover mathematical relationships that underlie groups with physical applications. Due to physical symmetries, we study how the irreducible representations of groups that embody the actions of even the most basic rotations are utilized in the computation of irreducible representations groups that reflect more complicated mechanics, …

Assessment Of Dune Change Using Historical Aerial And Satellite Photos, Topographic Surveys, And Wave Data At Toro Creek Beach, Owen D. Emerson

Master's Theses

Coastal sand dunes play an important role in the littoral processes of California’s coastline. Functioning as both source and sink for sand, these dunes often protect coastal infrastructure and provide a buffer between anthropogenic development and coastal forces. At Toro Creek Beach, north of Morro Bay California, recent extreme winter storms have raised concerns about the erosion of the sand dunes that front California State Highway 1. This thesis attempts to characterize the historical growth and recession patterns of the Toro Creek dunes since 1977, the dune movement over the 2023-2024 winter seasons, the wave forcings behind recent high erosion …

Enabling Emg-Based Silent Speech Transcription Through Speech-To-Text Transfer Learning, Alexander T. Garcia

Master's Theses

In recent years, advances in deep learning have allowed various forms of electrographic signals, such as electroencephalography (EEG) and electromyography (EMG), to be used as a viable form of input in artificial intelligence applications, particularly for applications in the medical field. One such topic that EMG inputs have been used is in silent speech interfaces, or devices capable of processing speech without an audio-based input. The goal of this thesis is to explore a novel method of training a machine learning model to be used for silent speech interface development: using transfer learning to leverage a pre-trained speech recognition model …

Supervised Classification Modeling On Louisiana Medicaid Data: A Comparative Study, Yead Rahman

Master's Theses

This thesis systematically optimizes and compares state-of-the-art supervised classification models for Louisiana Medicaid data targeting clinical services, COVID-19 infection, and tobacco use. These target variables are critically important as they represent key health outcomes and behaviors among Medicaid enrollees in Louisiana, a population often characterized by poverty and limited access to education. This study applies advanced machine learning techniques to identify the best model for multinomial and binary classification tasks. These include models such as Logistic Regression, XGBoost, AdaBoost, Random Forest, Decision Tree, Artificial Neural Networks, and Naïve Bayes. Extensive tuning of the hyperparameters and optimization of each classifier were …

Robotic Odor Source Localization Using Vision And Olfaction Sensing, Sunzid Hassan

Master's Theses

Robotic Odor Source Localization (ROSL) technology allows autonomous agents like robots to find an odor source in unknown environments. A successful odor source location depends crucially on an effective navigation algorithm that directs the robot towards the odor source. This thesis is a combination of three projects. First, we detail development of a versatile multi-modal robotic platform for ROSL real-world ROSL experimentation and discussed real-world validation of a traditional olfactionbased ROSL algorithm. Secondly, we introduced vision in ROSL by proposing a fusion navigation algorithm that integrates deep-learning enabled vision and olfaction-based navigation. This hybrid approach tackles challenges such as turbulent …

Absolute Quantification Of Human Myosin And Titin Isoforms In Disease By A Mass Spectrometry Approach, Nitha Aima Muntu

Master's Theses

Heart failure (HF) is the leading cause of death worldwide and produces an immense economic burden. Dilated cardiomyopathy (DCM), characterized by contractile weakness and chamber dilation, is a significant cause of HF. The sarcomeric proteins play a crucial role in regulating the contractile properties of the heart. As the primary motor protein, the expression of cardiac myosin isoforms (α-MHC and β-MHC) dictates the performance and cardiac energy utilization of the sarcomere. Titin is the giant spring protein in the sarcomere, and titin isoform expression impacts the passive stiffness of the myocardium. Small changes in the α-MHC/β-MHC and titin isoform ratios …

Remote Sensing With Airborne Infrared Thermography For Assessment Of Landscape Scale Wildfire Spread And Intensity, Christopher C. Giesige

Master's Theses

Wildland fire is one of the most complex environmental physical processes to quantify. The way in which we observe and measure wildland fire is critical in understanding how these processes drive fire dynamics. Fire behavior can be observed in several ways including the use of ground sensors and remote sensing packages aboard aircraft and satellites. Airborne sensors provide high spatial resolution and can provide high temporal resolution. Infrared thermography takes advantage of radiant heat transfer allowing for the study of fire characteristics such as fire spread and intensity. Aircraft observations utilizing infrared cameras have been a well-established method of fire …

Analyzing Live And Dead Fuel Moisture In California: Insights For Wildfire Management Decisions, Jack R. Drucker

Master's Theses

This study investigates trends in fuel moisture content (FMC) across California from 2000 to 2021. It utilizes two distinct sources of FMC data: the Fuel Moisture Repository, which integrates live fuel moisture content (LFMC) observations, and a novel dead fuel moisture content (DFMC) reanalysis product which provides spatial fuel moisture maps by integrating dead fuel moisture observations and a fuel moisture model driven by gridded weather data. The analysis uncovered a general downtrend in FMC across California, with the exception of LFMC in the Northernmost regions and coarse DFMC. Despite the differing long-term FMC trends, all the regions experienced a …

On The Colorability Of The Sphere Complex, Bennett Haffner

Master's Theses

One of the most prominently studied groups in geometric group theory is the outer automorphism group of the free group Out(F). The sphere complex provides a topological model for Out(F). We demonstrate the chromatic number of the sphere complex is finite.

Flora And Fauna Lexical Indicators Of Prehistoric Movement Of Yuman Peoples, Adam Ingwerson

Master's Theses

Amyloid fibrils are locally ordered protein aggregates characterized by a filamentous morphology held together by a hydrogen bonding motif known as cross-β structure whereby hydrogen bonds form between backbone amide bond moieties across separate protein segments. The most notable medical significance of amyloid fibrils is their central role in the etiology of Alzheimer’s disease, type 2 diabetes, and other human diseases. Although amyloid fibrils have been studied extensively, the mechanism of their formation is still not fully understood. X-ray crystallography is a leading experimental technique for resolving amyloid fibril structures from crystallized proteins; however, inherent limitations leave open the possibility …

Deep-Learning Approaches To Predict Remaining Useful Life Of Hard Disks, Rohan Mohapatra

Master's Theses

On a daily basis, data centers process huge volumes of data using inexpensive hard disks. Data stored in these disks serve a range of critical functional needs from financial, and healthcare to aerospace. As such, premature disk failure and consequent loss of data can be catastrophic. To mitigate the risk of failures, cloud storage providers perform condition-based monitoring and replace hard disks before they fail. By estimating the remaining useful life (RUL) of hard disk drives, one can predict the time-to-failure of a particular device and replace it at the right time, ensuring maximum utilization whilst reducing operational costs. We …

Synthetic Data Generation For Accurate, Fair, And Private Recommender Systems, Derek B. Lilienthal

Master's Theses

A notorious challenge for recommender systems on online platforms is to accurately and fairly recommend items that align with users’ preferences while retaining user privacy. These systems often rely on historical data that is partially labeled and includes incomplete user information, leading to the over-representation of majority groups and disproportionately favoring popular items. Substituting user data with synthetic data can address these concerns, but accurately replicating real-world datasets has been a challenging problem. Recent advancements in generative AI have demonstrated the impressive capabilities of diffusion models in generating realistic data across several domains. In this work, we introduce two variations …

Reinforcement Learning Based Planning And Control For Robotic Source Seeking Inspired By Fruit Flies, Gauravkumar Koradiya

Master's Theses

In the exploration of mobile sensing agents such as robots equipped with sensors, these agents have the potential to measure unknown scalar fields, ranging from chemical concentrations to temperature fluctuations. One of the primary interests is the robots’ ability to gravitate towards the peaks or troughs of these fields, a phenomenon termed as “source seeking”. This behavior is invaluable in practical scenarios, like detecting chemical leaks or locating survivors after catastrophes. However, the challenge becomes significantly more pronounced when operating in turbulent flow fields, where the erratic nature of odorant plumes makes predictions and simulations highly unreliable. Interestingly, fruit flies …

Controllable Physics-Informed Latent Space For Acoustic Wave Manipulation, Tristan Shah

Master's Theses

Partial Differential Equations (PDEs) are foundational descriptive tools in scientific and engineering disciplines, enabling the exploration of phenomena from material design to climate dynamics and the propagation of pandemics and wildfires. Establishing control of PDEs, especially when the underlying phenomena are only partially observable, holds great potential for fostering technological innovations. This ambition faces considerable obstacles, as a robust sample-based solution remains elusive. Addressing this challenge, this thesis introduces a framework leveraging physics-informed machine learning (ML) to enable control of PDEs. Central to this framework is an agent, equipped with sensors to perceive its environment, that generates a low-dimensional physics-informed …

Structure Of The South-Central Skagit Gneiss Complex: Implications For Rheological Response To Magmatic Flare-Ups, Jeffery Wegener

Master's Theses

The Skagit Gneiss Complex in the North Cascades magmatic arc consists of Late Cretaceous to Eocene orthogneiss and partially migmatitic paragneiss. Orthogneiss protoliths intruded during two magmatic flare-ups, making the Skagit Gneiss an ideal location to study the relationship between flare-ups and deformation. Geologic mapping, microstructural analysis, and U-Pb dating of zircon were used to construct a timeline of magmatism, metamorphism and deformation in a portion of the Skagit Gneiss. A tonalitic gneiss intruded between ~79-73 at the beginning of the older flare-up and an ~60 Ma, tonalitic to granodioritic, leucocratic orthogneiss intruded at the end of this flare-up. NW-SE …

An Exploration Of Dimensionality Reduction Of Dynamics On Lie Groups Via Structure-Aware Canonical Correlation Analysis, Wooyoung Chung

Master's Theses

Incorporating prior knowledge into a data-driven modeling problem can drastically improve performance, reliability, and generalization outside of the training sample. The stronger the structural properties, the more effective these improvements become. Manifolds are a powerful nonlinear generalization of Euclidean space for modeling finite dimensions. When additionally assuming that the manifold carries (Lie) group structure, this imposes a drastically stricter global constraint. The range of their applications is very wide and includes the important case of robotic tasks. We apply this idea to Canonical Correlation Analysis (CCA). In traditional CCA one constructs a hierarchical sequence of maximal correlations of up to …

Assessing The Role Of Steam Explosivity In Shallow And Deep Marine Environments, Frederick Ede

Master's Theses

Volcaniclastic deposits formed in shallow and deep marine environments show strikingly different characteristics resulting from the ability of steam to assist in lava fragmentation. Deep marine deposits come from recent lava flows at Axial Seamount, formed around 1,500 m water depth, while shallow marine samples come from Miocene Columbia River Basalt Group (CRBG) lava flows that were emplaced in a shallow marine to subaerial environment and are now exposed on the Oregon coast. Volcaniclastic material from these two environments was compared using granulometry, componentry, and mapping. Lithofacies from the CRBG contained abundant ash and lapilli sized clasts with a high …

Application Of Agent-Based Simulation And Game Theory In Evaluating Implementation Of Whole Genome Sequencing In Treating Lung Cancer, Fateme Ghalenoei

Master's Theses

Cancer, particularly lung cancer, presents significant diagnostic and economic challenges globally. Timely diagnosis and cost management play pivotal roles in treatment success. A biomarker is any measurable molecule in blood, bodily fluids, or tissues, indicating the potential presence of an abnormal bodily process, condition, or disease. Biomarker testing is a laboratory test in oncology that is used in the selection of targeted cancer treatments and to help avoid ineffective treatments. Whole Genome Sequencing (WGS), is a biomarker test which while more comprehensive, comes at a higher cost. This study proposes an agent-based simulation model within a game-theoretic framework to examine …

Modeling, Simulation, And Experimental Testing Of A Single-Legged Hopper, John Anthony Bennett

Master's Theses

Legged robots are well-suited for navigating unstructured terrain due to their ability to perform agile dynamic motions. Building on the efforts of Cal Poly's Legged Robotics Group, this project focuses on achieving stable forward hopping with a single legged robot.

A comprehensive model of leg hopping is formulated, with leg dynamics during flight and stance phases derived using Euler-Lagrange equations. During the stance phase, a spring-mass system models the leg-ground interaction. The touchdown and lift-off conditions are formulated mathematically, and state mappings between phases are determined via momentum conservation. A two-phase hybrid controller is designed, incorporating trajectory planning during flight …

Contrast As A Governing Principle: Topic Deployment In Selected Sonatas Of Johann Christian Bach, Morgan Hall

Master's Theses

Between the end of the Baroque era and the end of the Classical era, there was a shift in the way music was composed. This shift allowed composers to employ multiple topics in one work as opposed to the single-affect-per-movement that was standard under the Doctrine of Affections. Despite plenty of scholarship about both of the eras, the transition from one to the other has been relatively unexplored. Early musicologist Charles Burney noted in a volume of his General History of Music that there was a composer who was the first to employ “contrast as a governing principle”, and this …

Investigating The Response Of The Eastern Oyster (Crassostrea Virginica) To Low Dissolved Oxygen Conditions, Abiola Obafemi

Master's Theses

The Eastern oyster (Crassostrea virginica) requires dissolved oxygen (DO) of about 4 mg/L to support proper physiological function. Hypoxia and/or microxia occur when DO decreases to ≤ 2 mg/L. Salinity and temperature changes resulting from large-scale freshwater influx have been identified as key factors influencing the oyster populations in the Mississippi Sound. It is important to investigate the impacts of DO conditions on oyster mortality, biomass, size, and condition during these freshening events. Under controlled laboratory experiments, this thesis investigated 1) the response of oysters to microxic, hypoxic, and normoxic conditions 2) the response of oysters to combined hypoxia and …