Digital Commons Network^™

A Feasibility Study On Series Hybrid-Electric Propulsion For Narrow-Body Transport Aircraft, Carver J. Glomb

Master's Theses

As global climate change accelerates, the reduction of carbon emissions has become a critical objective across multiple industries. The aviation sector, however, has lagged behind other transportation domains in implementing sustainable alternatives, despite growing demand for air travel. Recent research and emerging technologies have proposed several decarbonization pathways, including hydrogen fuel, sustainable aviation fuels (SAFs), and hybrid or fully electric propulsion systems. Among these, series hybrid-electric propulsion has received comparatively limited attention, particularly for application in transport-class aircraft. This study investigates the feasibility and emissions-reduction potential of a series hybrid-electric propulsion architecture applied to a representative narrow-body platform. A Python-based …

Optimizing Web Servers With Io_Uring, Mihika Nigam

Master's Theses

Modern web servers face unprecedented demands for high throughput and low latency [10] [11]. Yet, even the state-of-the-art optimizations often fail under heavy workloads on existing infrastructure. Despite advancements in hardware, communication between applications and the kernel remains a critical bottleneck.

Industry surveys reveal that over 50% of production servers still rely on traditional epoll-based architectures [5]. This research aims to investigate and characterize Linux’s new io_uring subsystem, which has the potential to overcome these challenges. Through controlled load testing of various existing architectures like event-driven, multi-process, and multi-threaded architectures (including other commercial servers), we demonstrate how io_uring can help …

Development And Testing Of A Lab-Scale Resonance Igniter For Rocket Propulsion Applications, Aidan Caplan

Master's Theses

The resonance igniter is a type of rocket engine ignition system that initiates spontaneous combustion without using an external ignition source. This is possible because the activation energy needed for the combustion reaction to take place is provided by the igniter as it receives propellant flow. This can simplify the igniter hardware and lends it high re-usability while enabling the use of high-efficiency propellant combinations. Its potential benefits could make it a desirable alternative to traditional approaches such as using spark igniters or hypergolic propellants. The present research strove to inaugurate the study of the resonance igniter at Cal Poly …

Efficient Gan-Based Adversarial Example Generation Against Ml-Based Network Intrusion Detection Systems, Darren D. Hartono

Master's Theses

In the realm of network security, Network Intrusion Detection Systems (NIDS) are essential for identifying and mitigating malicious activities targeting networked devices. Traditionally, these systems have relied on signature-based and anomaly-based detection techniques. However, the increasing complexity and adapt- ability of cyber threats have driven the adoption of Machine Learning (ML) ap- proaches in modern NIDS, significantly improving their ability to detect a wider range of attack vectors. Despite these advancements, ML-based NIDS remain vulnerable to adversarial examples—deliberately crafted inputs designed to mislead models and trigger incorrect classifications. Originally identified in the field of computer vision, adversarial examples now pose …

Hardware-In-The-Loop Testing For The Polysim Adcs Lab, Shealyn P. Miller

Master's Theses

Hardware-in-the-loop, HIL, testing is an important tool for the validation and verification of systems in the aerospace industry. A common subsystem to be tested using HIL testing is the attitude, dynamics, and controls subsystem, ADCS. This is due to HIL tests using realistic simulations of the space environment to control physical hardware. To create a HIL test, a simulation and HIL interface are needed to test and communicate with hardware. Using a Speedgoat Performance Real-Time Target Machine to communicate with a Raspberry Pi and a Simulink model, three tests were conducted to ensure communication was functioning properly. A simulation, in …

Clusters, Trends, And Choices: Feature Selection In Interactive Statistical Graphics, Dylan Le

Master's Theses

Exploratory data analysis (EDA) is a method for uncovering the structure and key characteristics of data, often through the use of statistical graphics. These visual tools can reveal patterns and trends, and their effectiveness can be enhanced through interactivity. By enabling users to filter data, zoom, and toggle visual features, interactive plots can accelerate and enrich the EDA process. This study extends a previous graphical study by incorporating an interactive framework. Using a statistical lineup protocol with two target patterns (a linear trend and a clustering trend) participants interacted with plots by toggling various aesthetic features, including cluster coloring, ellipses …

The Effect Of Whole Fruits High In Anthocyanins On Markers Of Glycemic Control In Women, Sophia C. Johnson

Master's Theses

Cardiometabolic diseases are a significant health burden worldwide and remain the leading cause of death among adults in the United States. Type 2 diabetes mellitus (T2DM) is a central component of cardiometabolic dysfunction and substantially increases the risk for cardiovascular disease. As women enter the post-menopausal period, significant declines in estrogen levels lead to a heightened risk of T2DM in this population. Observational and experimental evidence has shown potential for fruits high in anthocyanins (ACs) to reduce the risk of T2DM and improve glycemic control. This systematic review and meta-analysis examined the current research on whole fruits high in ACs …

Development Of A Novel Bio-Mimetic Ornithopter With Variable Flapping Angle, Geourg Kivijian

Master's Theses

From the beginnings of flight, flapping-winged flight has been a goal of many engineers to mimic and replicate. With gains in aerodynamic efficiency of flight and certain other favorable characteristics such as reduced noise, higher maneuverability, and surveillance opportunities in urban environments, flapping-wing aerial vehicle(FWAV) designs are consistently pursued in many corners of academia and industry. This thesis goes into the development of a flapping wing aerial vehicle with a Bio-mimetic novel drive mechanism that is cable-driven and can produce variable amplitude and frequency flapping stroke. Employing a Field-Oriented Control (FOC) Brushless Direct Current (BLDC) motor, paired with a bio-mimetic …

Design, Fabrication, And Testing Of A Dual-Rate Spring System For Mountain Bike Frames, Lucas P. Grizzle

Master's Theses

The design of full-suspension mountain bikes is a careful balance of suspension kinematics, structural dynamics, and manufacturing optimization for the expected use case. A bike designed to excel in one area will likely exhibit reduced performance in others. This optimization problem is addressed by designing, integrating, and testing a dual-rate spring system within a fully custom frame. The dual-rate spring is fully decoupled from the rest of the suspension kinematics, providing designers with an additional parameter to achieve ideal suspension behavior. This is accomplished by placing a thermoplastic polyurethane (TPU) bushing in series with the rear shock. The influence of …

Model-Based Design Of Compressed Lithium-Metal Pouch Cell Battery Modules For Evtol Applications, Scott J. Stirling

Master's Theses

Batteries with higher specific energy and power are essential for extending the range and performance of electric vertical takeoff and landing aircraft (eVTOLs). Anode-free lithium-metal pouch cells offer strong potential at the cell-level but require high compressive pressures to enhance cycle life and discharge performance. These pressures necessitate heavier structural components, reducing packaging efficiency at the module level.

To evaluate this tradeoff, a full-factorial enumeration model was developed to explore viable module designs within a constrained packaging volume. The model scales subsystem masses, enforces design rules and material limits, and accounts for large (~20%) cell thickness changes during cycling.

Results …

The Impact Of Accessibility Features On Player Experience In Video Games, Christine M. Widden

Master's Theses

While video game accessibility is a growing research topic, few studies investigate how players perceive the presence versus the absence of accessibility features, or how non-disabled players react to the option of accessibility features. This study explores these research gaps, investigating how access to accessibility features affects the experience of both disabled and non-disabled players. For the purposes of this study, a small platformer game was developed with as many accessibility features as feasible for the scope of the project. An A vs.\ B study was conducted in the game, with anonymous participants randomly assigned to version A, with all …

Development Of A Reaction Wheel System For Cal Poly’S Spacecraft Attitude Dynamics Simulator, Caleb Nalley

Master's Theses

The Cal Poly Spacecraft Attitude Dynamics Simulator (SADS) is an ongoing project to develop a system capable of simulating the attitude dynamics and kinematics of a rigid body in space. Actuations on the SADS are performed by reaction wheels, however the current reaction wheels have various issues that decrease system performance and are not independent of the SADS. The reaction wheel developed as part of this thesis will be designed to improve performance and set out design specifications tailored to the SADS, serve as an independent assembly that can be transferred to other systems, and provide a general outline for …

Study On The Application Of Smart Electric Meters For Secondary Voltage Protection, Jayaditya Sisodia

Master's Theses

The purpose of our research is to utilize PG&E’s Smart Meters installed across California to protect the Secondary Voltage delivered to the meter. This means detecting electrical faults between the utility’s distribution transformer and the installed Smart Meter. Our goal is to propose and implement various solutions through additional devices and protocols to detect and prevent these faults, communicate them with the meter, and forward fault information to the utility. A device will be designed to be installed on the transformer, detect faults, shut off power transmission, and communicate to the meter via fiber optic cable. Research will then be …

Open Source Asic Design Curriculum, Francisco Wilken

Master's Theses

The ever-growing importance of Application-Specific Integrated Circuits (ASICs) in a high-compute world necessitates that college graduates entering the workforce are well prepared to design them. This thesis details the design of novel ASIC curriculum, using open source tools to teach at the undergraduate level. By moving to a higher level of abstraction than classical transistor-focused coursework, chip design material can be made accessible earlier in an undergraduate degree. Additionally, open source tools provide a powerful, free, and portable platform for students to create their own designs, solving assignments focused on industry readiness. Finally, this thesis studies the results and challenges …

Thermally Perfect Augmentation Of A Supersonic Inlet Design Tool That Uses Method Of Characteristics, Mario V. Guardado

Master's Theses

This work is the first in a series to augment a supersonic air inlet design tool based in Python 3 to incorporate new models that increase the range of applicability of the tool. This effort focuses on improving the thermodynamics model by incorporating a thermally perfect gas model. This tool utilizes method of characteristics to solve the governing equations for an inviscid, irrotational, isentropic, steady, supersonic flow field. Multiple test cases are used to assess the accuracy of all new models. A comparison is made between the original code’s test case for a supersonic inlet at low temperatures to verify …

Reverse Engineering Bring Up And Profiling Of Multi-Fpga Systems, Henry A. Evans

Master's Theses

FPGAs have long been used for prototyping and verifying high-speed digital designs in industry and in academic research. As ASIC designs have grown in complexity and size, prototyping those designs on FPGAs has required multiple FPGAs that sometimes span multiple servers. Western Digital donated multiple FPGA-based systems to Cal Poly in 2023. These servers contain multiple high-end AMD FPGAs that are ideal for prototyping large high-speed digital designs, however the full documentation on how to use the servers and how the servers work was not provided. The servers did not come with any information on how to program the FPGAs, …

Griddle: A Novel Hardware Based Matrix Multiplier Architecture, Seth Kiefer

Master's Theses

Matrix multiplication is a computational cornerstone in modern artificial intelligence and scientific computing, yet general-purpose processors struggle to perform these operations efficiently at scale. This thesis presents Griddle, a novel hardware architecture for matrix multiplication implemented on a Xilinx Artix-7 FPGA. Griddle focuses on flexibility and scalability by adopting a purely iterative approach that supports arbitrarily shaped input matrices without requiring padding or strict dimensional constraints. The architecture uses computational pipelines to execute a multiplication operation. Each pipe consists of a multiplication core and accumulation buffer that compute matrix products in parallel. The multiplication core contains a set of multiplier …

Streamlined Intelligence: Resource-Efficient Machine Learning For 5g Nr V2v Channel Equalization, Jacqueline G. Radding

Master's Theses

As autonomous vehicles continue to evolve, reliable and efficient real-time communication between vehicles is essential for safety and performance. This thesis explores Streamlined Intelligence: Resource Efficient machine learning for 5G NR V2V Channel Equalization, focusing on lightweight random forest decision tree models to address the challenges of channel equalization in 5G New Radio (NR) vehicle to vehicle (V2V) systems. Using orthogonal frequency division multiplexing (OFDM) with QPSK modulation, the study simulates data transmission in nonlinear channels characterized by obstructions, Doppler shifts, and fading. Decision trees are proposed as a computationally efficient alternative to other machine learning methods while being compared …

"Great Big Beautiful Tomorrow": Disneyland, Science, And The Cultural Cold War, Emily Searson

Master's Theses

Disneyland, the popular Anaheim-based theme park in California, opened its doors during heightened Cold War tensions in 1955. In this thesis, I trace the origins of Tomorrowland, one of the five original themed lands in Disneyland that included futuristic rides and attractions to depict Walt Disney’s imagining of the year 1986. I examine Tomorrowland in particular to argue that WED Enterprises (Disneyland, Inc.’s research and development arm) and Disney’s vision of scientific progress aligned with U.S. Cold War policy goals, especially containment. Disney and WED Enterprises meticulously planned Tomorrowland with the help of notable American defense contractors, including the Monsanto …

Experimental Characterization And Finite Element Analysis Of The Effects Of Pitting Corrosion On The Mechanical Properties Of Stainless Steel, Duncan Jay Fure, Long Wang

Master's Theses

Many structures do not fail from poor design, but instead from environmental degradation. Corrosion is one mode whose effects can be diminished, but not eliminated, by employing corrosion resistant materials, such as 304 stainless steel, which are still subject to pitting corrosion. Pitting corrosion is a chemical process of the localized removal of material leaving cavities. Despite the prevalence of pitting corrosion, there has been limited testing conducted of the effect of stress during corrosion. This study conducted accelerated controlled corrosion experiments with and without mechanical loading and various corrosion times. Pit morphology of different conditions was analyzed with statistical …

Low Earth Orbit Drag Sail Degradation Due To Atomic Oxygen And Ultraviolet Radiation, Hannah Rost

Master's Theses

As the orbital debris population increases, so does the risk of collisions with operational spacecraft. In response, the Federal Communications Commission has shortened the deorbit requirement from 25 years to five years. While natural atmospheric decay was sufficient under the previous guideline, many objects with low area to mass ratios can no longer passively comply. Smaller, non-propellant-carrying space objects such as CubeSats lack the ability to maneuver and must rely on alternative deorbit methods. One proposed solution is to deploy a drag sail at end of life to increase atmospheric drag and accelerate orbital decay. However, exposure to atomic oxygen …

Design And Development Of A Half-Bridge Llc Resonant Converter Laboratory Module, Alyssa Lam

Master's Theses

Resonant DC-DC converters have become a well-known solution in power supplies due to their ability to improve efficiency by utilizing soft-switching techniques. This further has caused a growing interest in industry to use these converters for high-switching-frequency, high-efficiency, and high-power applications such as EV charging stations, photovoltaic systems, battery chargers, etc. One particular resonant topology that has gained popularity in recent years is the LLC resonant converter. Due to the prevalent use of the LLC resonant converter, it is therefore crucial for students preparing for a career path in power electronics to become well-versed in the concept and implementation of …

Tuned Liquid Damper Design Using Liquid Sloshing In A Horizontal Cylindrical Tank, Vedant M. Patel

Master's Theses

Vibration isolation is an essential design requirement for several real word applications including industrial machinery, automobiles and building structures. Different techniques of vibration isolation are employed in each of these applications. One such vibration isolator used in tall buildings is known as the Tuned Mass Damper , where a mechanical mass (pendulum, bogey, cylinder) is located at the top portion of the building and is connected to the building through a suspension. This mechanical mass – suspension system is designed to oscillate out of phase with the building in order to dissipate the vibration. Several buildings such as, Taipei 101, …

Coherent Synchronization For Distributed Digital Phased Arrays, Zachary C. Numa

Master's Theses

Distributed digital phased arrays are rising technologies that help enable applications such as search and rescue operations, wireless communication, radar navigation, and military operations, among many others. Due to their improved angular resolution, digital phased arrays offer superior direction-finding capabilities compared to traditional analog phased array systems. However, this improvement comes at the cost of increased complexity—specifically, the need for precise synchronization of phase, time, and frequency across physically separated nodes. Without synchronization, the distributed phased array's gain and direction-of-arrival (DoA) estimations deteriorate significantly.

There are multiple aspects to implementing and synchronizing a non-stationary distributed digital phased array. This research …

A Decision Support System For Conference Session Selection Using Natural Language Processing, Tillman E. Erb

Master's Theses

Conference attendees are faced with selecting from hundreds to thousands of presentations and sessions in pursuit of new findings and methods relevant to their area of interest, an overwhelming amount of information from which to clearly make a decision. To address this, we developed a decision support system leveraging natural language processing (NLP) techniques such as semantic matching. By creating and matching embeddings of conference presentation abstracts and titles, the application provides improved query matching compared to keyword searching. We introduce Session Scout, a novel conference decision support system built upon a semantic retrieval framework. Session Scout is designed to …

Open Source Microgrid Integration, Zachary J. Kwast

Master's Theses

Microgrids are small-scale electrical systems that operate in tandem with a centralized grid to provide power to a smaller group of target devices. These microgrids are used for a wide range of different purposes, which invites the need for a generalized model that can be tweaked for a variety of uses. This document goes over the theory used to design an open source AC and DC microgrid meant for use by anyone. The microgrid is created using a Raspberry Pi that controls two different power converters so that a wide range of voltage and current characteristics can be achieved. These …

Density-Based And Model-Based Clustering With Tidyclust In R, Brendan S. Callender

Master's Theses

Clustering is a fundamental technique in unsupervised learning that can be used to find hidden patterns and structures within unlabeled data. The tidyclust package in R provides a unified interface for applying various clustering techniques to data. This paper outlines the addition of density-based clustering with DBSCAN, and model-based clustering using Gaussian mixture models (GMMs) to the tidyclust package. DBSCAN can be performed using the db_clust() function and makes use of the dbscan package implementation as its engine. GMMs can be fit using the gm_clust() function which makes use of the mclust package implementation. This paper highlights the changes made …

Statistical Investigations Of Strategies In The Game Ecosystem, Dylan Li

Master's Theses

This work provides a probability-based analysis of strategies in the board game Ecosystem. Ecosystem is a turn-based multiplayer tiling game, where players take turns picking a wildlife card from a limited pool of cards then placing that card on their personal 4x5 grid. The objective of the game is to place the wildlife cards to maximize your score, as each card’s scoring condition depends on the presence or absence of certain cards surrounding it. The goal of this project is to determine optimal strategies for tiling your grid using techniques such as simulation to find optimal grid arrangements and clustering …

Bandwagon Behavior In Major League Baseball, Daniel E. Erro

Master's Theses

This study investigates “bandwagon” behavior among Major League Baseball (MLB) fans by analyzing Google search interest data from 2004 to 2019. Drawing on publicly available information from Google Trends, the analysis explores how fluctuations in search activity align with team performance during both the regular season and postseason. Hierarchical linear models are used to estimate expected levels of fan interest based on team performance and market characteristics. Deviations from these expectations during the regular season are interpreted as evidence of bandwagon or anti-bandwagon behavior. A drop-off in interest following playoff elimination is also examined to capture shifts in fan attention …

Babies, Babes, And Bayes: Modeling Mother-Infant Feedings With Bayesian Multilevel Hidden Markov Models, Zachary G. Felix

Master's Theses

Understanding the interaction between mother and baby during feeding is critical for the long-term development health of the baby. Overfeeding can lead to later obesity, while underfeeding can lead to malnutrition. In a recent study, the behaviors exhibited by mother-infant dyads across multiple ages of infants have been observed and coded according to the Baby Behaviors when Satiated (BABES) coding scheme. However, creating models using the data obtained from this coding is no simple task since the data coding is continuous, multivariate, and longitudinal in nature. The specific model utilized for these data is a hidden Markov model, since there …