Digital Commons Network^™

Design, Validation, And Verification Of The Cal Poly Educational Cubesat Kit Structure, Nicholas B. Snyder

Master's Theses

In this thesis, the development of a structure for use in an educational CubeSat kit is explored. The potential uses of this kit include augmenting existing curricula with aspects of hands on learning, developing new ways of training students on proper space systems engineering practices, and overall contributing to academic capacity building at Cal Poly and its collaborators. The design improves on existing CubeSat kit structures by increasing accessibility to internal components by implementing a modular backplane system, as well as adding the ability to be environmentally tested. Manufacturing of the structure is completed with both additive (Fused Deposition Modeling …

Solar Energy Generation Forecasting And Power Output Optimization Of Utility Scale Solar Field, Byungyu Kim

Master's Theses

The optimization of photovoltaic (PV) power generation system requires an accurate system performance model capable of validating the PV system optimization design. Currently, many commercial PV system modeling programs are available, but those programs are not able to model PV systems on a distorted ground level. Furthermore, they were not designed to optimize PV systems that are already installed. To solve these types of problems, this thesis proposes an optimization method using model simulations and a MATLAB-based PV system performance model. The optimization method is particularly designed to address partial shading issues often encountered in PV system installed on distorted …

Numerical Methods For Predicting The Dynamic Crushing Response And Energy Absorption Of Composite Aluminum Honeycomb Sandwich Structures, Cody R. Volk

Master's Theses

Edgewise crushing responses of composite aluminum honeycomb sandwich structures were predicted using finite element analysis (FEA) software LS-DYNA by modeling the honeycomb as a material with anisotropic properties. The goal of the project was to develop a process for modeling the sandwich structure to rapidly iterate possible solutions for a safer workstation train table. Current workstation tables are too rigid and may cause injury or death in a head-on collision. Experimental compression tests were used to calibrate the aluminum honeycomb core with material type 26 (MAT 26, honeycomb). A published composite tensile test was used to validate the use of …

Design Of A Printed Circuit Board For A Sensorless Three-Phase Brushless Dc Motor Control System, Joshua Castle

Master's Theses

The use of brushless motors has increased in recent years due to superior performance characteristics compared with alternatives. The operation of a brushless motor is dependent upon a separate controller which is often in the form of a printed circuit board. As such, the size and performance capability of the controller can restrict the performance of the overall motor control system so advancements of these controllers further the potential use of BLDC motors. This project outlines the design of a PCB based, sensorless motor controller for operation of a three-phase BLDC motor powered by a 24 V, high current external …

A Study Of The Standard Cirrus Wing Lift Distribution Versus Bell Shaped Lift Distribution, William H. Bergman

Master's Theses

This thesis discusses a comparison of the differences in aerodynamic performance of wings designed with elliptical and bell-shaped lift distributions. The method uses a Standard Cirrus sailplane wing with a lift distribution associated with the induced drag benefits of an elliptical distribution (span efficiency = 0.96) as the basis of comparison. The Standard Cirrus is a standard class sailplane with 15-meter wingspan that was designed by Schempp-Hirth in 1969. This sailplane wing was modeled and analyzed in XFLR5, then validated against existing wind tunnel airfoil data, and Standard Cirrus flight test data. The root bending moment of the baseline wing …

Attractiveness Of English Thyme (Thymus Vulgaris L.) To Arthropod Natural Enemies And Its Suitability As A Dual Use Resource, Kristina K. Van Wert

Master's Theses

Current agroecosystem management practices have a negative effect on natural enemies and their ability to control insect pests. Conservation biological control through the addition of flowering resources can manage food resources for natural enemies. These floral resources can also provide multiple ecosystem services. Study goals were to determine if perennial Thymus vulgaris L. was attractive to natural enemies and if so, could it be a dual use resource encouraging pest management and providing harvestable product. In 2018 plots in three locations were used to examine the effect of habitat throughout the growing season on the attractiveness of T. vulgaris. …

Investigation Of New Forward Osmosis Draw Agents And Prioritization Of Recent Developments Of Draw Agents Using Multi-Criteria Decision Analysis, Jodie Wei Yu

Master's Theses

Forward osmosis (FO) is an emerging technology for water treatment due to their ability to draw freshwater using an osmotic pressure gradient across a semi-permeable membrane. However, the lack of draw agents that could both produce reasonable flux and be separated from the draw solution at a low cost stand in the way of widespread implementation. This study had two objectives: evaluate the performance of three materials — peptone, carboxymethyl cellulose (CMC), and magnetite nanoparticles (Fe₃O₄ NPs) — as potential draw agents, and to use multi-criteria decision matrices to systematically prioritize known draw agents from literature for …

Bootstrapping Massively Multiplayer Online Role Playing Games, Mitchell Miller

Master's Theses

Massively Multiplayer Online Role Playing Games (MMORPGs) are a prominent genre in today's video game industry with the most popular MMORPGs generating billions of dollars in revenue and attracting millions of players. As they have grown, they have become a major target for both technological research and sociological research. In such research, it is nearly impossible to reach the same player scale from any self-made technology or sociological experiments. This greatly limits the amount of control and topics that can be explored. In an effort to make up a lacking or non-existent player-base for custom-made MMORPG research scenarios A.I. agents, …

The Yanks Are Striking: Kern County, The 1921 Oil Strike And The Discourse On Americanism, Peter F. Hussey

Master's Theses

In the fall of 1921 oil workers of the San Joaquin Valley faced a post-war economic slump, wage cuts across the board and an increasingly hostile attitude of oil operators towards consultation with the federal government on labor relations. They voted to strike, and the next day eight thousand workers walked off the fields. Strikers crafted an image of “patriotic unionism,” underpinned by a faith in the federal government and the ideology of the American Legion. The strike did not end in gruesome class warfare like had been seen months earlier in the coal mines of West Virginia, but rather …

Towards Security And Privacy In Networked Medical Devices And Electronic Healthcare Systems, Isabel Jellen

Master's Theses

E-health is a growing eld which utilizes wireless sensor networks to enable access to effective and efficient healthcare services and provide patient monitoring to enable early detection and treatment of health conditions. Due to the proliferation of e-health systems, security and privacy have become critical issues in preventing data falsification, unauthorized access to the system, or eavesdropping on sensitive health data. Furthermore, due to the intrinsic limitations of many wireless medical devices, including low power and limited computational resources, security and device performance can be difficult to balance. Therefore, many current networked medical devices operate without basic security services such …

Writing For Each Other: Dynamic Quest Generation Using In Session Player Behaviors In Mmorpg, Sean Christopher Mendonca

Master's Theses

Role-playing games (RPGs) rely on interesting and varied experiences to maintain player attention. These experiences are often provided through quests, which give players tasks that are used to advance stories or events unfolding in the game. Traditional quests in video games require very specific conditions to be met, and for participating members to advance them by carrying out pre-defined actions. These types of quests are generated with perfect knowledge of the game world and are able to force desired behaviors out of the relevant non-player characters (NPCs). This becomes a major issue in massive multiplayer online (MMO) when other players …

Initial Orbit Determination Error Analysis Of Low-Earth Orbit Rocket Body Debris And Feasibility Study For Debris Cataloguing From One Optical Facility, Kyle Stoker

Master's Theses

This paper is predicated on determining the effectiveness of angles-only initial orbit determination (IOD) methods when limited observational data is available for low-Earth orbit (LEO) rocket body debris. The analysis will be conducted with data obtained from Lockheed Martin Space’s Space Object Tracking (SpOT) facility, focusing on their observational data from 2018 that contains tracking of rocket body debris for less than one minute per overhead pass. After the IOD accuracies are better understood, a feasibility study will follow that investigates the possibility of cataloguing LEO orbital debris from a single optical observation facility with similar observational capabilities as that …

A Floristic Study Of The Cal Poly Swanton Pacific Ranch And A New Combination In Sanicula Crassicaulis (Apiaceae), Sanicula Crassicaulis Var. Nudicaulis, Reed J. Kenny

Master's Theses

Globally we are experiencing a biodiversity crisis and potentially a sixth mass extinction event. Plant specimens are one of the best, most concrete records of biodiversity that we can create. Despite this, the rate of plant collecting has declined steeply since World War II. Now more than ever, plant collections are vital, both for the purpose of quantifying the plant biodiversity in an area and for discovering previously unrecognized diversity.

In Chapter 1, we conducted a floristic survey of the Cal Poly Swanton Pacific Ranch. The Swanton Pacific Ranch (SPR) is located north of the small town of Davenport California, …

Attacking Computer Vision Models Using Occlusion Analysis To Create Physically Robust Adversarial Images, Jacobsen Loh

Master's Theses

Self-driving cars rely on their sense of sight to function effectively in chaotic and uncontrolled environments. Thanks to recent developments in computer vision, specifically convolutional neural networks, autonomous vehicles have developed the ability to see at or above human-level capabilities, which in turn has allowed for rapid advances in self-driving cars. Unfortunately, much like humans being confused by simple optical illusions, convolutional neural networks are susceptible to simple adversarial inputs. As there is no overlap between the optical illusions that fool humans and the adversarial examples that threaten convolutional neural networks, little is understood as to why these adversarial examples …

Host Plant Resistance In Strawberries To Anthracnose And Colonization Of Crown And Root Tissue By Verticillium Dahliae And Macrophomina Phaseolina, Omar A. Gonzalez-Benitez

Master's Theses

Strawberries are considered an important crop in California where in 2018 it was in the top 5 valued fruit and vegetable commodities valued at $2.84 billion accounting for 88% of the total U.S. production. Strawberry production can be severely impacted by soilborne pathogens that can affect strawberry roots, crowns and leaves which can result in plant mortality. As much as 50 to 60% mortality can occur in one field. Pathogens responsible for such losses include Colletotrichum acutatum (syn.C. nymphaeae), Macrophomina phaseolina and Verticillium dahliae. With the phaseout of methyl bromide, host resistance and an understanding of host-pathogen interactions …

The Strawberry Rhizosphere Microbiome: Role On Plant Health And Nutrition, Eric Michael Boyd

Master's Theses

Microbial-root associations are important to help plants cope with abiotic and biotic stressors. Managing these interactions offers an opportunity for improving the efficiency and sustainability of agricultural production. By characterizing the bacterial and archaeal community (via 16S rRNA sequencing) associated with the bulk and rhizosphere soil of sixteen strawberry cultivars in two controlled field studies, we explored the relationships between the soil microbiome and plant resistance to two soilborne fungal pathogens of strawberry (Verticillium dahliae and Macrophomina phaseolina). Overall, the plants had a distinctive rhizosphere microbiome relative to the bulk soil, with higher abundances of known beneficial bacteria …

Barriers To Success: Sheep And Goat Producers In The Service-Grazing Industry, Erin A. Campbell-Craven

Master's Theses

Service-grazing is a novel term for grazing done on land not owned or rented by a livestock producer or manager, for the purpose of land management, and for which the owner or land manager receiving grazing services pays compensation to the service provider. This research project seeks to gather detailed information about producers in the Western United States, providing grazing services under this project’s definition of “service-grazing”, with a focus on those operating in California, in order to discover the business models or practices necessary to be successful within a service-based grazing operation. To this end, an online survey consisting …

Cal Poly Pier Master Plan, Troy A. Lawson

Master's Theses

The Cal Poly Pier (Pier) Master/Facility Plan (FP) document provides the vision of the future for the Pier, a marine science research facility. The Plan facilitates project development and management of the Pier while meeting university and department research goals. Specifically, the FP document establishes goals and strategies to direct long-term development of the Pier, streamlines agency approval and permit requirements, provides context for pier management, and assists the permitting process for future development as it relates to regulatory permits and programmatic growth on the Cal Poly Pier to help meet goals of the Center for Coastal Marine Sciences (CCMS). …

Mindfulness For Stress Reduction: Qualitative Analysis Of Perceptions From College Students And Mindfulness Instructors, Beth Marie Merlo

Master's Theses

Although mindfulness interventions with college students have yield positive results, many students are not continuing to engage after the interventions. This may be because very little research has been done to investigate the health behavior beliefs of college students in regard to mindfulness for stress reduction. The purpose of this investigation was to identify the most influential components of the Integrated Behavioral Model (IBM) that potentially assist with predicting college student participation in mindfulness activities for stress reduction. Interviews, informed by the IBM, were conducted with 20 current college students and 5 current mindfulness instructors working with college students. The …

Analysis Of Aquifer And Operational Conditions For Successful Soil Aquifer Treatment Of Treated Wastewater Via Synthesis Of Published Full-Scale And Laboratory-Scale Studies, Matthew I. Murray

Master's Theses

Soil aquifer treatment (SAT) of treated wastewater performance was evaluated across published full-scale and lab-scale studies developing insights on the aquifer and operational factors that affect SAT efficacy. The goal of this study was to develop a basis for predicting the contaminant removal capabilities of any given aquifer during managed recharge with treated wastewater.

Over 40 published SAT studies were reviewed and systematically compared to determine the influence of five major factors on contaminant removal performance: geologic composition, geochemical conditions, hydrogeological conditions, operational methods, and source water quality. Removal mechanisms for standard contaminants (dissolved and total organic carbon, nitrogen, and …

Analysis And Optimization Of Colorimetric Nanosensors For Rapid Detection Of Microbes In Water, Ruby A. Lang

Master's Theses

Access to safe water is a basic human right recognized by the United Nations General Assembly in 2010 (WHO, 2020). However, a least 2.2 billion people globally still are without safely managed water services meaning they use a drinking water source that can be contaminated with faeces (WHO, 2020). With such a pressing global health issue, it is clear that improvement to water systems is important and required in the Agenda 2030 Sustainable Development Goals (SDGs). However, to improve water systems and prove they are safe water sources, water quality testing must occur. A solution to this issue is the …

Pier Portal, Alec W. Hardy

Master's Theses

The Pier Portal marine monitoring system is an internet controlled underwater camera that will enable students, researchers, and the general public the ability to monitor underwater marine life and ocean conditions. Installed at Cal Poly’s Center for Coastal Marine Science pier at Avila Beach, California, the camera can be commanded in real-time to raise or lower to any position between the top of the pier and the bottom of the ocean floor, while providing a live-stream video to the operator and general public. This thesis effort focused on the integration of the various subsystem components through software, and the development …

Planning For Pollinators, Encouraging Biodiversity For Agriculture Resiliency, Sebastian Brian Cardoza

Master's Theses

Pollinators are essential to food production globally. Without them, the production of food becomes increasingly difficult, time consuming, and costly. Unfortunately, due to the rapid changes to our earth's physical and climatic structure millions of species are becoming classified as threatened, endangered or extinct. Among these declining species are pollinating insects such as Aphis mellifera (honeybee) and other native species. This is due to a phenomenon known as colony collapse disorder (CCD) and other native bees. The decline indicates that the future habitability of earth may be in jeopardy. The solution to this crisis is to expand the habitat of …

Review Of Mentoring Manuals In Stem To Improve The Mentorship Experience For Underrepresented Minority Students Through The Lens Of Social Capital And Combating Social Reproduction, Leno Kurimoto

Master's Theses

There is a lack of diversity and inclusion in STEM (science, technology, engineering, and mathematics) education. Students who pursue a degree in STEM, only less than half of them complete them. However, this phenomenon occurs at a greater percentage for underrepresented minority students (UMS). To combat the lack of representation in STEM, mentoring has been suggested to promote retention and minimize attrition. Mentoring provide plenty of benefits for students, as they can gain academic and professional experience. Unfortunately, mentorship of UMS is not the same compared to Asian and white students, thus different approaches and recommendations must be implemented to …

Student Government Leaders And Their Roles In Cooperative Transformative Change On Campus: An Examination Of Undergraduate Changemakers At A California University, Robert Jittrikawiphol

Master's Theses

The purpose of this paper is to examine attitudes, beliefs, and feelings of student government leaders at a large West Coast research University where they enjoy a high level of autonomy in decision making and how the ability to be a partner in institutional transformation translates to personal and professional leadership development. Interviews were conducted with a number of individuals who served as campus-wide elected officials who represented the undergraduate student body. The interview participants talked about their experiences with faculty, staff, and administrators while involved in student government.

Results showed that when given access to information and considered on …

The Practice Of Cantus Planus Binatim As Reflected In John Plousiadenos's Pro-Union Communion Hymns, Simeon Brown

Master's Theses

No abstract provided.

Assessing The Relationship Between Narcissism, Neuroticism, And Leadership Skills, Krista Marie Brooker

Master's Theses

Understanding personality traits that are related to leadership skills is important in order to hire effective leaders. Research has seldom examined the relationship between narcissism, neuroticism, and leadership skills. Therefore, the present study was conducted to examine the relationship between narcissism, neuroticism, and leadership skills (human skills and conceptual skills). It was hypothesized that narcissism would be positively related to human skills and conceptual skills. It was also hypothesized that neuroticism would be negatively related to human skills and conceptual skills. A total of 145 employees participated in the self-report survey. Results showed that there was no relationship between narcissism …

A Code Reputation System Using Ai And Blockchain Technology, Jeremy Chau

Master's Theses

Open source development is a method of development in which source code is developed using the combined skills of the public. A few examples of this sort of development would be the Chromium and Linux kernel projects hosted on GitHub. Open source development offers a wide variety of benefits and disadvantages. A main concern is when many people blindly trust developers without second thought. There is a lack of a rating system that judges those who develop code through open source means. This can call into question the quality of the code being written by the individual as well as …

Life Between The Bridges: A Personal History Of San Francisco, Eli Hansen

Master's Theses

Life Between the Bridges: A Personal History of San Francisco is a hybrid work of history, memoir, and travel writing in which I seek to examine the city of San Francisco through a variety of lenses. The prologue provides an overview of experiences a newcomer to San Francisco might expect. The first chapter examines the current state of the city and addresses the pressing issue of high housing costs. This chapter also introduces the theme of optimism, a unifying concept throughout my thesis. I then provide a brief biography of my childhood and outline the events that led me to …

Evaluation Of Silica Hydride Based Amide Stationary Phase For High Performance Liquid Chromatography And Aqueous Normal Phase Separations, Emma Tardiff

Master's Theses

With many modern chromatographic advancements, silica hydride based columns (also known commercially as Type-C) represent yet another evolutionary step in stationary phase development. Type-C silica hydride columns have the ability to retain both polar and nonpolar analytes and have the ability to behave in either RP or ANP modes of separation depending on mobile phase composition. A consequence of this increased stability is that Type-C columns can be used over a wide range of mobile phase compositions, from purely aqueous to purely nonpolar organic solvents, and any combination of the two. While the retention behavior of Type-C columns depends highly …