Digital Commons Network^™

Modeling Action Potential Propagation During Hypertrophic Cardiomyopathy Through A Three-Dimensional Computational Model, Julia Elizabeth Kelley

Master's Theses

Hypertrophic cardiomyopathy (HCM) is the most common monogenic disorder and the leading cause of sudden arrhythmic death in children and young adults. It is typically asymptomatic and first manifests itself during cardiac arrest, making it a challenge to diagnose in advance. Computational models can explore and reveal underlying molecular mechanisms in cardiac electrophysiology by allowing researchers to alter various parameters such as tissue size or ionic current amplitudes. The goal of this thesis is to develop a computational model in MATLAB and to determine if this model can accurately indicate cases of hypertrophic cardiomyopathy. This goal is achieved by combining …

Modeling And Control Of A Vertical Hopping Robot, Bradley Y. Kwan

Master's Theses

Single degree-of-freedom hopping robots are typically modeled as spring loaded inverted pendulums (SLIPs). This simplified model, however, does not consider the overall leg geometry, consequently making it difficult to investigate the optimized inertial distribution of the leg for agile locomotion. To address this issue, the first part of this thesis establishes an accurate mathematical model of a DC-motor-driven, two-link hopping robot where the motors are modeled as torque sources. The equations of motion for the two distinct phases of locomotion (stance and flight) are derived using the Lagrangian approach for holonomic systems. A Simulink/Stateflow model is developed to numerically simulate …

Failure Analysis Of The Ulnar Collateral Ligament For Youth Baseball Pitchers, Carlos Soto

Master's Theses

The objectives of this study were to (1) use kinetics from motion analysis and inverse dynamics to calculate the stress experienced by the ulnar collateral ligament (UCL) during a typical pitch cycle, (2) compare calculated maximum UCL pitching stresses to failure properties, and (3) investigate correlations between UCL stress with anthropometric and pitching biomechanical parameters. Prior motion analysis experiments of eighteen 10- to 11- year-old baseball pitchers throwing 10 fastballs were analyzed. Maximum internal elbow varus torques were calculated using inverse dynamics methods during a typical pitch cycle. Calculations used axial loading stress equations and maximum internal elbow varus torques …

Scalable Cognitive Radio Network Testbed In Real Time, Kevin Z. Yu

Master's Theses

Modern society places an increasingly high demand on data transmission. Much of that data transmission takes place through communication over the frequency spectrum. The channels on the spectrum are limited resources. Researchers realize that at certain times of day some channels are overloaded, while others are not being fully utilized. A spectrum management system may be beneficial to remedy this efficiency issue. One of the proposed systems, Cognitive Radio Network (CRN), has progressed over the years thanks to studies on a wide range of subjects, including geolocation, data throughput rate, and channel handoff selection algorithm, which provide fundamental support for …

A Power System-Based Iot Network For Remote Sensing Applications, Dominic Gaiero

Master's Theses

Cities around the world are facing increasingly significant challenges, including rapid urbanization, resource management, and environmental threats. In California for example, wildfires present an ever-growing threat that gravely harms people, destroys communities, and causes billions of dollars in damages. The task of addressing these environmental threats and many other challenges is greatly aided with widespread data collection and real-time inference. However, as IoT networks scale and require more energy for near-data analytics, the IoT endpoints require more power and complexity, limiting their deployment. Additionally, deploying endpoints in remote locations creates further challenges with higher reliability and communication constraints. In this …

Reducing Vale's Memory Management Overhead Through Static Analysis, Theodore C. Watkins

Master's Theses

Vale is a multi-purpose programming language that focuses on guaranteeing memory safety with minimal effect on performance. To accomplish this, Vale utilizes a memory management system called Hybrid Generational Memory (HGM). HGM uses generational references to track the state of objects in memory, and static analysis to reduce memory management overhead at runtime. This thesis describes the program that performs static analysis on Vale source code during compilation, and analyzes its effect on the performance of Vale programs.

Prediction Of In-Plane Stiffnesses And Thermomechanical Stresses In Cylindrical Composite Cross-Sections, Bryson M. Chan

Master's Theses

Accurate mechanical analysis of composite structures is necessary for the prediction of laminate behavior. Cylindrical composite tubes are a mainstay in many structural applications. The fundamental design of circular composite cross-sections necessitates the development of a comprehensive composite lamination theory. A new analytical method is developed to characterize the behavior of thin-walled composite cylindrical tubes using a modified plate theory. A generated numerical solver can predict properties such as axial stiffness, bending stiffness, layer stresses, and layer strains in composite tubes subjected to combined mechanical loading and thermal effects. The model accounts for the curvature by transforming and translating the …

Cultivating Creativity In Aerospace Systems Engineering To Manage Complexity, Kenneth Lucas Dodd

Master's Theses

In recent decades, complexity in aerospace programs has been increasing, leading to large budget and schedule overruns. Many of the risks of complex system development can be attributed to the inadequacy of linear methods when applied to nonlinear domains, i.e., oversimplification in a program amplifies the amount of risk produced when a system behaves unexpectedly. Effectively managing complexity involves responding to the various sources of complexity, whether it appears in the objective behavior of the system itself or in the subjective behavior of the people developing it. Thus, the engineering of complex systems requires nonlinear modeling methods of the system …

An Artificial Neural Network For Bankruptcy Prediction, Walter D. Magdefrau

Master's Theses

Assessing the financial health of organizations remains a topic of great interest to economists, financial institutions, and invested stakeholders. For more than a century, research into financial distress has focused primarily on traditional applications of statistical analysis; however, modern advances in computational efficiency have created a significant opportunity for more sophisticated approaches. This thesis investigates the application of artificial intelligence on company bankruptcy prediction. The proposed neural network model is evaluated using the Polish Companies Bankruptcy dataset and yields a 5-year prediction accuracy of 96.5% and an AUC (area under receiver operating characteristic curve) measure of 92.4%.

Simulation Of A Configurable Hybrid Aircraft, Brandon Bartlett

Master's Theses

As the demand for air transportation is projected to increase, the environmental impacts produced by air travel will also increase. In order to counter the environmental impacts while also meeting the demand for air travel, there are goals and research initiatives that aim to develop more efficient aircraft. An emerging technology that supports these goals is the application of hybrid propulsion to aircraft, but there is a challenge in effectively exploring the performance of hybrid aircraft due to the time and money required for safe flight testing and due to the diverse design space of hybrid architectures and components. Therefore, …

Modeling The Groundwater Basin In The Northern Cities Management Area, Allyson Swain

Master's Theses

A model was developed to simulate the groundwater of 8,300 acres of the Northern Cities Management Area (NCMA), which encompasses the northern portion of the Arroyo Grande Watershed and a small subset of the Santa Maria Valley Groundwater Basin. This watershed and groundwater basin is located on the coast and contains Oceano and the Cities of Arroyo Grande, Grover Beach, Pismo Beach. Groundwater in the NCMA is used heavily for agricultural irrigation in the southern portion and municipal applications in the northern portion. Up to 18 of these municipal wells and over 50 irrigation wells are drawing groundwater at any …

Design And Characterization Of Standard Cell Library Using Finfets, Phanindra Datta Sadhu

Master's Theses

The processors and digital circuits designed today contain billions of transistors on a small piece of silicon. As devices are becoming smaller, slimmer, faster, and more efficient, the transistors also have to keep up with the demands and needs of the daily user. Unfortunately, the CMOS technology has reached its limit and cannot be used to scale down due to the transistor's breakdown caused by short channel effects. An alternative solution to this is the FinFET transistor technology, where the gate of the transistor is a three dimensional fin that surrounds the transistor and prevents the breakdown caused by scaling …

Perishable Food Waste Reduction Through Technological Implementation At The Retail Level Of The Food Supply Chain, Cassandra Harriman

Master's Theses

Food waste has become a disaster of global proportion that the world can no longer turn a blind eye to. This paper aims to reduce food waste at the retail level of the food supply chain by recommending and quantifying the effects of current technology that can be implemented in traditional supermarkets. This research recommends that retailers implement electronic shelf labels in stores and employ dynamic pricing of perishable products, leading to reduction of food waste. No prior research had considered the primary goal of reducing food waste while preserving retailer profit through technological implementation. This paper quantifies the effects …

Energy Efficient Computing Using Scalable General Purpose Analog Processors, Ethan Paul Palisoc De Guzman

Master's Theses

Due to fundamental physical limitations, conventional digital circuits have not been able to scale at the pace expected from Moore’s law. In addition, computationally intensive applications such as neural networks and computer vision demand large amounts of energy from digital circuits. As a result, energy efficient alternatives are needed in order to provide continued performance scaling. Analog circuits have many well known benefits: the ability to store more information onto a single wire and efficiently perform mathematical operations such as addition, subtraction, and differential equation solving. However, analog computing also comes with drawbacks such as its sensitivity to process variation …

Understanding The Impact Of The Covid-19 Pandemic Within Educational Communities Using Longitudinal Analysis, Alexa Steidl

Master's Theses

At California State University, Los Angeles and California Polytechnic University, San Luis

Obispo, a longitudinal survey was created in response to the COVID-19 pandemic for students within their respective engineering departments. A combination of nonparametric and longitudinal analysis is performed to evaluate the impacts of the transition to a virtual educational environment and the stressors brought on by the global pandemic. Additional qualitative evaluation is performed to gain insight and make program recommendations to enhance the resilience of individuals in the academic systems. Results demonstrate a large shift in circumstances immediately at the start of the pandemic, with a variety …

Transfer Learning Approach To Powder Bed Fusion Additive Manufacturing Defect Detection, Michael Wu

Master's Theses

Laser powder bed fusion (LPBF) remains a predominately open-loop additive manufacturing process with minimal in-situ quality and process control. Some machines feature optical monitoring systems but lack automated analytical capabilities for real-time defect detection. Recent advances in machine learning (ML) and convolutional neural networks (CNN) present compelling solutions to analyze images in real-time and to develop in-situ monitoring.

Approximately 30,000 selective laser melting (SLM) build images from 31 previous builds are gathered and labeled as either “okay” or “defect”. Then, 14 open-sourced CNN were trained using transfer learning to classify the SLM build images. These models were evaluated by F1 …

First Order Self-Oscillating Class-D Circuit With Triangular Wave Injection, Matthew J. Carroll

Master's Theses

An investigation into performance improvements to the modulator stage of a class-D amplifier is conducted in this thesis. Two of the standard topologies, namely class-D open-loop pulse-width modulation (PWM), and the improved self-oscillating feedback system are benchmarked against a topology which includes both a hysteretic comparator in a feedback loop and triangle wave injection. Circuit performance is analyzed by comparing how the triangle injection circuit handles known issues with open-loop and self-oscillating circuits. Using this analysis, it is shown that the triangle injection topology offers an improved power supply rejection ratio relative to open-loop PWM and reduces distortion generated by …

Using Pitch Tipping For Baseball Pitch Prediction, Brian Ishii

Master's Theses

Data Analytics and technology have changed baseball as we know it. From the increase in defensive shifts to teams using cameras in the outfield to steal signs, teams will try anything to win. One way to gain an edge in baseball is to figure out what pitches a pitcher will pitch. Pitch prediction is a popular task to try to accomplish with all the data that baseball provides. Most methods involve using situational data like the ball and strike count. In this paper, we try a different method of predicting pitch type by only looking at the pitcher's pose in …

Implementing A Data Acquisition System For The Training Of Cloud Coverage Neural Networks, Weston C. Montgomery

Master's Theses

Cal Poly is home to a solar farm designed to nominally generate 4.5 MW of electricity. The Gold Tree Solar Farm (GTSF) is currently the largest photovoltaic array in the California State University (CSU) system, and it was claimed to be able to produce approximately 11 GWh per year. These types of projections come from power generation models which have been developed to predict power production of these large solar fields. However, when it comes to near-term forecasting of power generation with variable sources such as wind and solar, there is definitely room for improvement.

The two primary factors that …

A Github-Based Voice Assistant For Software Developers And Teams, Siriwan Sereesathien

Master's Theses

Software developers and teams typically rely on source code and tasks management tools for their projects. They tend to depend on different platforms such as GitHub, Azure DevOps, Bitbucket, and GitLab for task-tracking, feature-tracking, and bug-tracking to develop and maintain their software repositories. Individually, developers may lose concentration when having to navigate through numerous screens consisting of various platforms to perform daily tasks. Additionally, while in meetings (non-virtual), teams are often separate from their machines and often would have to rely on pure recollection of the tasks and issues related to their work. This can delay the decision-making process and …

Analysis And Optimization Of A Colorimetric Nanosensor For Rapid Detection Of Escherichia Coli In Water, Sarah M. Stabler

Master's Theses

Safe drinking water is essential for life, yet at least two billion people around the world consume water contaminated with pathogens among other pollutants. Standard methods like polymerase chain reaction (PCR) and membrane filtration have been developed to detect enteric pathogens in water. However, these methods are limited in their accessibility due to long wait times to obtain results, and the requirements of skilled expertise, electricity, and laboratory equipment. This research has focused on addressing some of these limitations by analyzing the mechanisms of work and optimizing an indirect colorimetric nanosensor developed in previous research. The colorimetric nanosensor investigated herein …

Development Of A Portable Low-Moisture Food Pasteurization Device Using Rf Heating, Eric Jason Ohata

Master's Theses

Bacterial presence in low-moisture foods such as flour, cereals, baby formula, and spices, have become a concern due to sanitizing challenges. The food industry currently focuses on wet food sanitation as opposed to low-moisture foods because of bacteria’s inability to reproduce in low water activity media. Traditionally, food processing RF heating pasteurizes in mass quantities while an equivalent consumer device does not exist the market today. A consumer product would help eliminate food waste by providing an easy way to sanitize food and extend shelf life. The Portable Food Pasteurization (PFP) project is an interdisciplinary project involving the Electrical Engineering, …

Dependencyvis: Helping Developers Visualize Software Dependency Information, Nathan Lui

Master's Theses

The use of dependencies have been increasing in popularity over the past decade, especially as package managers such as JavaScript's npm has made getting these packages a simple command to run. However, while incidents such as the left-pad incident has increased awareness of how vulnerable relying on these packages are, there is still some work to be done when it comes to getting developers to take the extra research step to determine if a package is up to standards. Finding metrics of different packages and comparing them is always a difficult and time consuming task, especially since potential vulnerabilities are …

Groundwater Model Studying Effects Of Existing Recharge Basin And Proposed Subsurface Barrier For A Ranch In Santa Rosa Creek Watershed, Stefan J. Young

Master's Theses

A groundwater model of a 126.2-acre ranch in Cambria, California was expanded upon to analyze the effects of artificial recharge and a subsurface barrier. The ranch lies within the 48mi² Santa Rosa Creek Watershed along the Central Coast of California. The mainly agricultural watershed outfalls to the Pacific Ocean to its west. Creek Lands Conservation, a non-profit that aims to conserve and restore habitat along the Central Coast, plans to identify projects to restore stream flow during dry seasons in the creek that runs through the Santa Rosa Creek Watershed and to increase artificial groundwater recharge. This study focuses …

A Study Of Implementation Methodologies For Distributed Real Time Collaboration, Lauren A. Craft

Master's Theses

Collaboration drives our world and is almost unavoidable in the programming industry. From higher education to the top technological companies, people are working together to drive discovery and innovation. Software engineers must work with their peers to accomplish goals daily in their workplace. When working with others there are a variety of tools to choose from such as Google Docs, Google Colab and Overleaf. Each of the aforementioned collaborative tools utilizes the Operational Transform (OT) technique in order to implement their real time collaboration functionality. Operational transform is the technique seen amongst most if not all major collaborative tools in …

Modeling And Solving The Outsourcing Risk Management Problem In Multi-Echelon Supply Chains, Arian A. Nahangi

Master's Theses

Worldwide globalization has made supply chains more vulnerable to risk factors, increasing the associated costs of outsourcing goods. Outsourcing is highly beneficial for any company that values building upon its core competencies, but the emergence of the COVID-19 pandemic and other crises have exposed significant vulnerabilities within supply chains. These disruptions forced a shift in the production of goods from outsourcing to domestic methods.

This paper considers a multi-echelon supply chain model with global and domestic raw material suppliers, manufacturing plants, warehouses, and markets. All levels within the supply chain network are evaluated from a holistic perspective, calculating a total …

Design And Modeling Of A Distributed Network For The Dc House Project, Lauren N. Rotsios

Master's Theses

This thesis covers the design and simulation of a model for a distributed network of DC Houses in MATLAB Simulink. The model will allow for sharing of power between houses within the network. The developed model consists of five separate DC House branches with local power generation. Each branch consists of a PV MPPT charge controller subsystem, a resistive load, and a bidirectional buck-boost converter subsystem. The high voltage side of every bidirectional buck-boost converter is connected together through the transmission line at a single high voltage DC bus. The performance of the individual components of the model is verified …

Design And Implementation Of A Modular Human-Robot Interaction Framework, Michael J. Juri

Master's Theses

With the increasing longevity that accompanies advances in medical technology comes a host of other age-related disabilities. Among these are neuro-degenerative diseases such as Alzheimer's disease, Parkinson's disease, and stroke, which significantly reduce the motor and cognitive ability of affected individuals. As these diseases become more prevalent, there is a need for further research and innovation in the field of motor rehabilitation therapy to accommodate these individuals in a cost-effective manner. In recent years, the implementation of social agents has been proposed to alleviate the burden on in-home human caregivers. Socially assistive robotics (SAR) is a new subfield of research …

Evaluation Of Blood Vessel Mimic Scaffold Biocompatibility, Nicole M. Abraham

Master's Theses

The Tissue Engineering Research Lab at California Polytechnic State University, San Luis Obispo focuses on creating tissue-engineered blood vessel mimics (BVMs) for use in preclinical testing of vascular devices. These BVMs are composed of electrospun scaffolds made of an assortment of polymers that are seeded with different cell types. This integration of polymers with cells leads to the need for biocompatibility testing of the polymer scaffolds. Many of the lab’s newest scaffolds have not been fully characterized for biologic interactions. Therefore, the first aim of this thesis developed methods for in vitro cytotoxicity testing of polymers used in the fabrication …

The Application Of Post-Hoc Correction Methods For Soft Tissue Artifact And Marker Misplacement In Youth Gait Knee Kinematics, Kaila L. Lawson

Master's Theses

Biomechanics research investigating the knee kinematics of youth participants is very limited. The most accurate method of measuring knee kinematics utilizes invasive procedures such as bone pins. However, various experimental techniques have improved the accuracy of gait kinematic analyses using minimally invasive methods. In this study, gait trials were conducted with two participants between the ages of 11 and 13 to obtain the knee flexion-extension (FE), adduction-abduction (AA) and internal-external (IE) rotation angles of the right knee. The objectives of this study were to (1) conduct pilot experiments with youth participants to test whether any adjustments were necessary in the …