Digital Commons Network^™

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 …

Short Arc Initial Orbit Determination For Leo Objects And The Impact Of Observation Eelevation On Predictive Accuracy, Alexis Digregorio

Master's Theses

The expansion of space activities has led to an increase in congestion. With this increase, there has been a growing emphasis on the importance of space situational awareness. Without it, the space environment can become hazardous, with increasing threats of collision and debris generation. As the utilization of space continues to grow, effective methods for tracking objects to maintain situational awareness must also be considered. One approach to tracking objects in space involves a series of steps, including optical observations and orbit estimations using initial orbit determination methods, followed by additional observations and continuous tracking. However, a challenge with this …

Modeling The Acoustic Transmission Line With Applied Damping, Connor C. Getz

Master's Theses

The transmission line is an underappreciated style of loudspeaker enclosure characterized by an acoustic labyrinth stemming from the rear of the speaker driver. In practice, the transmission line enclosure produces airy sound uncharacteristic of other styles, at the cost of more pronounced resonant peaks. The most important practical drawback of this loudspeaker enclosure design is the difficulty of properly applying damping to these enclosures. Ideally, this difficulty can be mitigated using an analytical model that accurately predicts the SPL frequency response of a transmission line loudspeaker system for a given geometry and mass of damping material.

This research takes the …

Sizing Wind Tunnel Heater For High Enthalpy Conditions, Justin M. Slavick

Master's Theses

This paper determines the feasibility of adding a heater to an existing blowdown supersonic wind tunnel to unlock new high-enthalpy test applications, considering cost and power requirements at a variety of different states. This process includes both modeling the current range of test section properties in Cal Poly's blowdown wind tunnel and determining the new range of properties that a heat exchanger could induce. These results are verified with a computational fluid dynamics study. Additionally, sublimation and ablation properties of materials are explored to create appropriate models to study atmospheric re-entry once the heat exchanger is implemented.

It is found …

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 …

Predicting Rheology Of Uv-Curable Nanoparticle Ink Components And Compositions For Inkjet Additive Manufacturing, Cameron D. Lutz

Master's Theses

Inkjet additive manufacturing is the next step toward ubiquitous manufacturing by enabling multi-material printing that can exhibit various mechanical, electronic, and thermal properties. These characteristics are realized in the careful formulation of the inks and their functional materials, but there are many constraints that need to be satisfied to allow optimal jetting performance and build quality when used in an inkjet 3-D printer. Previous research has addressed the desirable rheology characteristics to enable stable drop formation and how the metallic nanoparticles affect the viscosity of inks. The contending goals of increasing nanoparticle-loading to improve material deposition rates while trying to …

Representation Theory And Its Applications In Physics, Max Varverakis

Master's Theses

Representation theory, which encodes the elements of a group as linear operators on a vector space, has far-reaching implications in physics. Fundamental results in quantum physics emerge directly from the representations describing physical symmetries. We first examine the connections between specific representations and the principles of quantum mechanics. Then, we shift our focus to the braid group, which describes the algebraic structure of braids. We apply representations of the braid group to physical systems in order to investigate quasiparticles known as anyons. Finally, we obtain governing equations of anyonic systems to highlight the differences between braiding statistics and conventional Bose-Einstein/Fermi-Dirac …

Design And Characterization Of A Broadband Rf Switch Utilizing Surface Mount Devices, Daniel Bracamontes

Master's Theses

High frequency solid-state switches are critical elements in communication systems, radio frequency (RF) systems and instrumentation. Key parameters to an RF switch include insertion loss while on and off-state isolation. Power handling and linearity are important to consider for a cost-effective construction. This becomes a design challenge into K-band frequencies as components required need to be small, dielectric losses and transmission lines need to be physically matched for proper isolative and through states. This thesis presents a novel single pole eight throw (SP8T) hybrid design composed of commercially available surface mount technology solutions to achieve high isolation and low insertion …

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 …

Performance Interference Detection For Cloud-Native Applications Using Unsupervised Machine Learning Models, Eli Bakshi

Master's Theses

Contemporary cloud-native applications frequently adopt the microservice architecture, where applications are deployed within multiple containers that run on cloud virtual machines (VMs). These applications are typically hosted on public cloud platforms, where VMs from multiple cloud subscribers compete for the same physical resources on a cloud server. When a cloud subscriber application running on a VM competes for shared physical resources from other applications running on the same VM or from other VMs co-located on the same cloud server, performance interference may occur when the performance of an application degrades due to shared resource contention. Detecting such interference is crucial …

Sonifind: A Sonified Micro-Guidance Interface For The Visually Impaired, Lucas Li

Master's Theses

We introduce Sonifind, a micro guidance system implemented on a smartphone that uniquely integrates computer vision and spatial audio intended to assist users who are visually impaired. Currently, micro guidance systems require head-mounted displays and various hardware, limiting their practicality for everyday use. Our system employs an off-the-shelf computer vision library and a smartphone to interpret the user's surroundings and provide intuitive spatial audio cues for real-time guidance. We conducted a between-subjects study with sighted, blindfolded participants to evaluate the learnability, performance, and user satisfaction of Sonifind using two different versions of the system to further inform our ongoing design …

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, …

Contrastive Filtering And Dual-Objective Supervised Learning For Novel Class Discovery In Document-Level Relation Extraction, Nicholas Hansen

Master's Theses

Relation extraction (RE) is a task within natural language processing focused on the classification of relationships between entities in a given text. Primary applications of RE can be seen in various contexts such as knowledge graph construction and question answering systems. Traditional approaches to RE tend towards the prediction of relationships between exactly two entity mentions in small text snippets. However, with the introduction of datasets such as DocRED, research in this niche has progressed into examining RE at the document-level. Document-level relation extraction (DocRE) disrupts conventional approaches as it inherently introduces the possibility of multiple mentions of each unique …

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 …

Artificial Intelligence For Mitigation Against Array Perturbations In Direction Of Arrival Estimation, Mathew Shaham

Master's Theses

Direction of Arrival (DOA) estimation with digital arrays under unknown Gaussian distributed element location perturbation has detrimental effects to the performance of traditional DOA estimation techniques. This work proposes an artificial intelligence (AI) approach as a solution to this problem. A Deep Convolutional Neural Network (DCNN) is proposed and experimentation into network parameters, classification networks, and how the DCNN is applied to the DOA problem are studied. It is shown that this AI based approach is successful in estimating the DOA with perturbed arrays where traditional approaches fail.

Balancing Darkness And Visibility: An Algorithmic Approach To Light Placement In Low-Light, Ray-Traced Scenes, Briana Kuo

Master's Theses

In recent years, digital media has seen incredible advancements in rendering visually stunning computer graphics scenes. Photo-realistic games, animated films, and more leave viewers blown away by the sheer beauty of their graphics. However, challenges arise when depicting dark scenes, often resulting in visual monotony and difficulty in comprehension due to insufficient detail within the scene. In order to enhance readability and visual interest of a scene, additional, artificial lights can be placed throughout a scene to enhance the aesthetic. These lights, however, must be strategically placed in order to retain an essence of darkness and maintain the delicate balance …

Design And Assembly Of A Variable Buoyancy System For An Autonomous Underwater Vehicle, Evan Brown

Master's Theses

Autonomous underwater vehicles (AUVs) play a vital role in the surveillance and mapping of our oceans, often requiring extensive travel in extreme environments. These data-gathering missions benefit from extended durations, making the minimization of power consumption a key consideration in AUV design. One effective strategy to reduce energy use in AUVs is to implement a variable buoyancy system (VBS) for depth control. The purpose of this work is to design, develop, test, and model a variable buoyancy system to enhance the efficiency and capabilities of a high-speed, long-range AUV.

After evaluating various VBS designs, a piston-cylinder buoyancy system was selected …

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 …

Implementation And Efficiency Of Electric Motors In Lygus Bug Vacuums For Strawberries, Adam J. Rantz

Master's Theses

Further automation of the agricultural industry and an increase in organic fruit production are needed to address labor shortage and increased demand. The move to an autonomous bug vacuum is easier if the equipment is electric, and not powered by a tractor’s PTO (power take-off) shaft. The main objective of this project was to design a set of lygus bug vacuums to go on a robot that meets industry standards while using electric power instead of hydraulic. The frame of the vacuum was designed using the industry standard. While hydraulic systems have been a very effective power source for vacuums …

Qwixx Strategies Using Simulation And Mcmc Methods, Joshua W. Blank

Master's Theses

This study explores optimal strategies for maximizing scores and winning in the popular dice game Qwixx, analyzing both single and multiplayer gameplay scenarios. Through extensive simulations, various strategies were tested and compared, including a scorebased approach that uses a formula tuned by MCMC random walks, and race-to-lock approaches which use absorbing Markov chain qualities of individual score sheet rows to find ways to lock rows as quickly as possible. Results indicate that employing a scorebased strategy, considering gap, count, position, skip, and likelihood scores, significantly improves performance in single player games, while move restrictions based on specific dice roll sums …

Design And Analysis Of A New Buck-Boost Converter With A Low-Side Switch, Abdullah Awidah

Master's Theses

This work explores the design, simulation, construction, and analysis of a novel Non-isolated DC-DC Buck-Boost converter which has the advantage of incorporating a low-side switch compared to the traditional buck-boost which requires a high-side switch. This allows the use of a low-side driver which further simplifies the design and operation of the converter. The proposed Buck-Boost converter was constructed to provide -24 V output from an input range of 12V-18V with 15V nominal input at 10W maximum output power utilizing 500kHz switching frequency. Findings from simulations and hardware tests verify that the converter effectively provides the desired -24 V output …

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 …

Feasibility And Characterization Of Leak-Tight Single-Track Thin Walls Produced By Laser Powder Bed Fusion In 316l Stainless Steel, Peyton J. Archibald

Master's Theses

This thesis explores the optimization of process parameters for producing single-track thin walls using Laser Powder Bed Fusion (LPBF) additive manufacturing. Using two different coupon designs, the study assesses the feasibility of creating the thinnest possible leak-tight structures within LPBF and evaluating their mechanical properties, including burst pressure and modulus of elasticity under pressure loads. A series of experimental iterations were conducted, varying laser power and laser speed to identify optimal conditions. The findings indicate that a narrow range of process parameters can produce consistently leak-tight thin walls. The results contribute to understanding how to achieve high quality, reliable thin …

The Impact Of Video Assistant Referee (Var) On The English Premier League, Jack Kenyon Brown

Master's Theses

The aim of this study is to examine how the introduction of the Video Assisted Referee (VAR) system influenced the English Premier League (EPL). Since its implementation in the English Premier League in 2019, VAR has been a constant source of debate and controversy. Many studies have been done on the immediate impact of VAR on other elite professional soccer leagues, but the scope of results is very limited and due to be updated. The data for the ensuing analysis consists of 3800 matches played in the English Premier League during the five seasons before (14/15, 15/16, 16/17, 17/18, and …

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 …

Instant Hdr-Nerf: Fast Learning Of High Dynamic Range View Synthesis With Unknown Exposure Settings, Nam Nguyen

Master's Theses

We propose Instant High Dynamic Range Neural Radiance Fields (Instant HDR-NeRF), a method of learning high dynamic range (HDR) view synthesis from a set of low dynamic range (LDR) views with unknown and varying exposure and white balance in as little as minutes. Our method can render novel HDR views without ground-truth supervision, and novel LDR views in different exposure settings, including those that match the ground-truth LDR views. The key to our method is to model the physical process of the camera with two implicit MLPs: a radiance field and a monotonically increasing tone-mapper. Built upon Instant Neural Graphics …

Recursive Marix Game Analysis: Optimal, Simplified, And Human Strategies In Brave Rats, William A. Medwid

Master's Theses

Brave Rats is a short game with simple rules, yet establishing a comprehensive strategy is very challenging without extensive computation. After explaining the rules, this paper begins by calculating the optimal strategy by recursively solving each turn’s Minimax strategy. It then provides summary statistics about the complex, branching Minimax solution. Next, we examine six other strategy models and evaluate their performance against each other. These models’ flaws highlight the key elements that contribute to the effectiveness of the Minimax strategy and offer insight into simpler strategies that human players could mimic. Finally, we analyze 123 games of human data collected …