Digital Commons Network^™

Multiple Input Single Output Converter With Uneven Load Sharing Control For Improved System Efficiency, Kristen Y. Chan

Master's Theses

This paper presents the development and study of multiple-input single-output converter (MISO) for the DC House project that utilizes a controller to maximize the overall converter’s efficiency. The premise of this thesis is to create uneven load current sharing between the converters at different loading conditions in order to maximize the efficiency of the overall MISO converter. The goal is to find a proper ratio of current from each converter to the total load current of the MISO system to achieve the greatest efficiency. The Arduino microcontroller is implemented to achieve this goal. The design and operation of the MISO …

A Novel Arc Welding Power Supply With Improved Power Factor Correction, Benjamin H. Tan

Master's Theses

This paper presents the design and development of a novel Arc Welding Power Supply utilizing a modified two-switch forward converter topology. The proposed design improves the power quality by improving power factor to near unity and reducing total harmonic distortion. State space analysis of the proposed circuit showed that the circuit followed a boost-buck input output relationship. Simulation of the circuit was first implemented in LTspice to verify the functionality of the new topology. Hardware implementation of the proposed design was built on a scaled-down prototype for a proof-of-concept of the new topology. The prototype specifications were created for a …

The Effect Of Sex Of Firstborn Children On Fertility Preferences, Lauren Lamson

Master's Theses

Fertility rates around the world are falling at the same time that male-skewed sex ratios at birth are on the rise. The individual fertility choices people make contribute to this inverse relationship, exacerbating the problem of “missing women” as well as a number of other adverse social and economic effects. The decision to have a child is extremely complex. Distilling the interaction between fertility and sex compositional preferences, fertility levels, and gender norms is an important step toward understanding both the reproductive choices people make as well as the formation of fertility preferences. I use individual-level data from the Demographic …

Evaluating Methods To Reduce Humpback Whale (Megaptera Novaeamgliae) Ship Strike Mortality In Nearshore Feeding Habitats Within The San Francisco Bay, Alisa Keenan

Master's Theses

Across our world’s oceans, whales are perpetually stuck and killed by large ships. Sea-based commercial trade is increasing on a global scale; therefore, more large ships are circumnavigating through biologically important whale habitats. This is of grave concern to marine resource managers, especially in the United States where major shipping corridors overlap critical whale habitat. It is feared that in these areas with high whale density, ship strikes are reducing populations of whales to levels below what is sustainable for threatened and endangered species, thereby hindering the recovery of depleted whale populations. Humpback whales, a species that is federally-listed as …

Educational Equity And Informal Stem Field Trip Programming, Sal Alper

Master's Theses

Informal STEM field trip programming is a large, yet under-researched area of the education landscape. Informal STEM education providers are often serving a more privileged section of society, leading to a risk of perpetuating inequalities seen throughout the education landscape. In an attempt to address the lack of research, this thesis explores the relationship between educational equity and informal STEM field trips. The intention was to collect data using a critical ethnography approach to the methods of qualitative questionnaire and interviews of informal STEM educators. A change in circumstances from the global pandemic of COVID-19 caused a shift in this …

A Comparison Of Power Variables For Two Loading Methods In Weighted Vertical Jumps 2020, Jonathan Tanguay

Master's Theses

Training exercises to develop muscular strength and power, such as the weighted jump squat, commonly utilize barbells and dumbbells to increase resistance. Strength coaches often measure improvements in peak force, peak power, and rate of force development to determine effectiveness of a training program. The purpose of this study was to determine if equipment selection (barbells vs. dumbbells) affects peak force, peak power, and/or rate of force development in weighted jump squats. Thirteen physically active, college-aged males (age: 21.6 ± 2.0 years, height: 182.8 ± 9.7 cm, body mass: 87.2 ± 9.0 kg, lean mass: 72.3 ± 8.1 kg) performed …

Neural Network Pruning For Ecg Arrhythmia Classification, Isaac E. Labarge

Master's Theses

Convolutional Neural Networks (CNNs) are a widely accepted means of solving complex classification and detection problems in imaging and speech. However, problem complexity often leads to considerable increases in computation and parameter storage costs. Many successful attempts have been made in effectively reducing these overheads by pruning and compressing large CNNs with only a slight decline in model accuracy. In this study, two pruning methods are implemented and compared on the CIFAR-10 database and an ECG arrhythmia classification task. Each pruning method employs a pruning phase interleaved with a finetuning phase. It is shown that when performing the scale-factor pruning …

Neural Representation Of Articulable And Inarticulable Novel Sound Contrasts: The Role Of The Dorsal Stream, David Saltzman

Master's Theses

No abstract provided.

Thermal Ecology Of The Federally Endangered Blunt-Nosed Leopard Lizard, Kathleen N. Ivey

Master's Theses

Recognizing how climate change will impact populations can aid in making decisions about approaches for conservation of endangered species. The Blunt-nosed Leopard Lizard (Gambelia sila) is a federally endangered species that, despite protection, remains in extremely arid, hot areas and may be at risk of extirpation due to climate change. We collected data on the field-active body temperatures, preferred body temperatures, and upper thermal tolerance of G. sila. We then described available thermal habitat using biophysical models, which allowed us to (1) describe patterns in lizard body temperatures, microhabitat temperatures, and lizard microhabitat use, (2) quantify the …

Valorization Of Carrot Processing Waste, Alexandra M. Duval

Master's Theses

Commercial carrot processors produce up to 175,000 tons of carrot waste annually. Carrot Mash (CM) is the term referring to the waste by-product of peeled baby carrot processing. Transportation of carrot processing waste is expensive due to its high- water content (approx. 83-95%). High in bioactive compounds (carotenoids) and dietary fibers, it is expected that its conversion into a value-added by-product is of interest to the carrot processing industry. Hemicellulose-rich plant materials have proven to be a source of oligosaccharides, which are known for their beneficial prebiotic activity. The objectives of this research were to: 1) determine the effect of …

Risk Factors For Poor Birth Outcomes In Moderately Malnourished Pregnant Women In Sierra Leone, Candice A. Rodriguez

Master's Theses

Background: Maternal malnutrition in developing countries is associated with adverse pregnancy and birth outcomes. Malnourished mothers are often faced with additional risk factors as a circumstance of poverty. Supplementary nutrition can improve the outcomes of both mother and infant. Identifying maternal nutritional and socioeconomic risk factors is critical for developing effective interventions.

Objective: A secondary analysis to evaluate maternal risk factors associated with poor birth outcomes including pregnancy loss, low birth weight, stunting, and preterm delivery among moderately malnourished pregnant women in Sierra Leone. Maternal risk factors in the analysis are age, education, parity, BMI, MUAC, gestational weight gain, and …

Subject-Specific Finite Element Models Of The Human Knee For Transtibial Amputees To Analyze Tibial Cartilage Pressure For Gait, Cycling, And Elliptical Training, Jonathon Stearns

Master's Theses

It is estimated that approximately 10-12% of the adult population suffers from osteoarthritis (OA), with long reaching burdens personally and socioeconomically. OA also causes mild discomfort to severe pain in those suffering from the disease. The incidence rate of OA for individuals with transtibial amputations is much than average in the tibiofemoral joint (TF). It is well understood that abnormal articular cartilage stress, whether that be magnitude or location, increases the risk of developing OA. Finite element (FE) simulations can predict stress in the TF joint, many studies throughout the years have validated the technology used for this purpose. This …

Fruit, Flower, And Thorn: A Phenological Study Of 'Wonderful' Pomegranate, Kylie M. Mendonca

Master's Theses

‘Wonderful’ pomegranate flowering and fruiting habits are not well understood. Characterizing any relationship between flowering habit and fruit size and quality could lead to effective cultural practices for producing high-value fruit. Five mature ‘Wonderful’ pomegranate trees were monitored every 5-14 days throughout the 2015 growing season. Newly emerged flowers were tagged and characterized with respect to sex (determined by ovary shape and style length at anthesis), clustering habit, age of wood on which floral buds were borne, and direction of wood growth. More than 1,100 hermaphroditic flowers were identified and ovary/fruit diameter was recorded throughout the season. In addition to …

Design And Implementation Of Stewart Platform Robot For Robotics Course Laboratory, Trent R. Peterson

Master's Theses

A Stewart Platform robot was designed, constructed, and programmed for use in Cal Poly’s ME 423 Robotics: Fundamentals and Applications laboratory section. A Stewart Platform is a parallel manipulator robot with six prismatic joints that has six degrees of freedom, able to be defined in both position and orientation. Its purpose is to supplement parallel robot material covered in lecture. Learning objectives include applying and verifying the Stewart Platform inverse kinematics and investigating the Stewart Platform’s operation, range of motion, and limitations. The Stewart Platform geometry and inverse kinematics were modeled and animated using MATLAB. The platform was then built …

Dynamic Procedural Music Generation From Npc Attributes, Megan E. Washburn

Master's Theses

Procedural content generation for video games (PCGG) has seen a steep increase in the past decade, aiming to foster emergent gameplay as well as to address the challenge of producing large amounts of engaging content quickly. Most work in PCGG has been focused on generating art and assets such as levels, textures, and models, or on narrative design to generate storylines and progression paths. Given the difficulty of generating harmonically pleasing and interesting music, procedural music generation for games (PMGG) has not seen as much attention during this time.

Music in video games is essential for establishing developers' intended mood …

Residual Strength Of Franciscan-Derived Clay, Yingyi Xu

Master's Theses

In February of 2017 after a period of heavy rainfall, a slope destabilized behind Fremont Hall on the campus of Cal Poly San Luis Obispo. The geology of this slope stability failure is the Franciscan Complex. The Franciscan Complex, when weathered in place, results in clay soil that makes up the typical soil mantle on the hills throughout the region. Peak strength is the typical parameter tested to assess the strength of the soil. For the Franciscan-derived clay, the residual strength is the focus of this study to understand slope failure since the clay is the weakest portion of the …

Decentralized, Noncooperative Multirobot Path Planning With Sample-Basedplanners, William Le

Master's Theses

In this thesis, the viability of decentralized, noncooperative multi-robot path planning algorithms is tested. Three algorithms based on the Batch Informed Trees (BIT*) algorithm are presented. The first of these algorithms combines Optimal Reciprocal Collision Avoidance (ORCA) with BIT*. The second of these algorithms uses BIT* to create a path which the robots then follow using an artificial potential field (APF) method. The final algorithm is a version of BIT* that supports replanning. While none of these algorithms take advantage of sharing information between the robots, the algorithms are able to guide the robots to their desired goals, with the …

Web Conference Summarization Through A System Of Flags, Annirudh M. Ankola

Master's Theses

In today’s world, we are always trying to find new ways to advance. This era has given rise to a global, distributed workforce since technology has allowed people to access and communicate with individuals all over the world. With the rise of remote workers, the need for quality communication tools has risen significantly. These communication tools come in many forms, and web-conference apps are among the most prominent for the task. Developing a system to automatically summarize the web-conference will save companies time and money, leading to more efficient meetings. Current approaches to summarizing multi-speaker web-conferences tend to yield poor …

Custodians Of Memory: A History Of American Archival Science With Suggestions For Future Digital Preservation Efforts, Courtney Thompson

Master's Theses

The archive and the historian are symbiotically dependent on one another. The archive relies on the historian to make use of the records it houses, and the historian looks to the archive to reconstruct history. But can a historian responsibly reconstruct history when the archive is fraught with relativity and bias? This thesis serves two purposes; one, pulling from seminal archival science and collections management texts, it chronicles the monumental, intellectual changes to American archival sciences, theories, and institutions, and two, it shows how these early conversations pertaining to archival theories are both not far removed from digital preservation efforts …

Methods To Increase Algae Biomass Productivity In Raceway Pond Monocultures, Ryan S. Anderson

Master's Theses

The economics of algae biofuels and bioproducts would be improved by increased biomass productivity. Two studies on this potential are described in this thesis – one on a locally isolated filamentous yellow-green alga and the other on a planktonic strain genetically improved via selective enrichment.

Polycultures have been viewed as productive, stable, and, in some cases, harvestable by natural bioflocculation. Local native strains might have higher productivity than culture collection strains because they are already adapted to local outdoor conditions. In this study, the filamentous yellow-green alga Tribonema minus was isolated from a local volunteer polyculture. Its productivity as a …

Skier's Edge: Biomechanical Analysis, Benjamin T. Johannes

Master's Theses

ABSTRACT

Skier’s Edge: Biomechanical Analysis

Benjamin T. Johannes

The Skier’s Edge trainer can be used by novice or expert skiers. Testing was performed to analyze if the use of the Skier’s Edge could reduce in shear forces of the valgus moment on the knee joint and anterior cruciate ligament (ACL) due to lesser fatigue of muscle and a higher hamstring to quadricep (H/Q) ratio activity. This leads to a reduction of improper form and an increase in balance. Experiments performed observed the change in muscle activity with the use of the Skier’s Edge over time when compared to other forms …

Use Of Body Composition Imaging To Calculate 3-D Inertial Parameters For Inverse Dynamic Analysis Of Youth Pitching Arm Kinetics, Dalton James Jennings

Master's Theses

The objectives of this study were to 1) calculate participant-specific segment inertial parameters using dual energy X-ray absorptiometry (DXA) data (referred to as full DXA-driven parameters) and compare the pitching arm kinetic predictions using full DXA-driven inverse dynamics vs scaled, DXA mass-driven (using DXA masses but scaled centers of mass and radii of gyration), and DXA scaled inverse dynamics(ID) (using the full DXA-driven inertial parameters averaged across all participants), 2) examine associations between full DXA-driven kinetics and body mass index (BMI) and 3) examine associations between full DXA-driven kinetics and segment mass index (SMI). Eighteen 10- to 11- year-olds pitched …

Insulative (Direct Current) Dielectrophoretic Foul-Less Filtration In Microfuidic Systems, Matthew A A Whitman

Master's Theses

Filtration is a technology that is used almost ubiquitously in society from uses raging from filtration of macroparticles from water to pharmaceutical grade filtration products to remove anything larger than a protein. However, with such a wide range of uses, most filtration products have the same issue; membrane clogging (fouling) that prevents continuous use and requires frequent maintenance. This thesis hypothesizes that by applying a direct current (DC) to an insulating array of posts, they will create a foul-less insulative dielectrophoretic filter (iDEP) that does not clog since particles will levitate above the insulating array.

This thesis tested an inherited …

Electricity Price Forecasting Using A Convolutional Neural Network, Elliott Winicki

Master's Theses

Many methods have been used to forecast real-time electricity prices in various regions around the world. The problem is difficult because of market volatility affected by a wide range of exogenous variables from weather to natural gas prices, and accurate price forecasting could help both suppliers and consumers plan effective business strategies. Statistical analysis with autoregressive moving average methods and computational intelligence approaches using artificial neural networks dominate the landscape. With the rise in popularity of convolutional neural networks to handle problems with large numbers of inputs, and convolutional neural networks conspicuously lacking from current literature in this field, convolutional …

Inactivation Of Foodborne Pathogens During Cider Fermentation, In A Cider Model System And Commerical Cider, Kathryn K. Yamada

Master's Theses

Hard cider is an alcoholic drink made from fermented crushed fruit, typically apples. The popularity of this fermented alcoholic beverage has been on the rise within the last decade. Historically, hard cider has been deemed safe due to the presence of ethanol and the low pH. Although there is lack of scientific evidence to prove that hard cider will and can be safe from foodborne pathogens. Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes are three predominate foodborne bacterial pathogens of concern in the food and beverage industry. Escherichia coli O157:H7 in particular has been associated with fresh produce and …

A System Architecture For Phased Development Of Remote Suas Operation, Eric Ashley

Master's Theses

Current airspace regulations require the remote pilot-in-command of an unmanned aircraft systems (UAS) to maintain visual line of sight with the vehicle for situational awareness. The future of UAS will not have these constraints as technology improves and regulations are changed. An operational model for the future of UAS is proposed where a remote operator will monitor remote vehicles with the capability to intervene if needed. One challenge facing this future operational concept is the ability for a flight data system to effectively communicate flight status to the remote operator. A system architecture has been developed to facilitate the implementation …

Patterns In Size Distribution And Catch Of Rockfish (Sebastes Spp.) In Fisheries-Independent And Fisheries- Dependent Hook-And-Line Surveys On The Central Coast Of California, Rose Elizabeth Dodgen

Master's Theses

Stock assessments are statistical models which characterize the state of a population of fish. Data for stock assessment models of West Coast nearshore groundfish come largely from fisheries-dependent sources. Incorporating fisheries-independent data would increase data availability. A potential source of fisheries-independent data which is comparable to existing fisheries-dependent data is the California Collaborative Fisheries Research Program (CCFRP), a Marine Protected Area (MPA) monitoring study. We are interested in understanding the context in which CCFRP could be implemented into assessments of nearshore groundfish, specifically rockfish. To investigate this, we used management-relevant metrics to examine three questions concerning the implementation of CCFRP …

Using Crispr-Cas9 As A Restriction Enzyme, Zack Crawley

Master's Theses

Restriction digests are a commonly utilized process for cleaving DNA at specific, but relatively common sites. Restriction enzymes have widespread use in DNA manipulation. CRISPR/Cas9 is a recently identified endonuclease which utilizes a customizable guide sequence to recognize and cut specific ~20 bp sites located in a DNA sequence. This preliminary research aimed to exploit the potential benefit of DNA restriction using the CRISPR/Cas9 procedure through alterations of different components involved in that system. We sought to refine existing CRISPR/Cas9 protocols and make a budget friendly, user-selectable CRISPR/Cas9 restriction digest protocol. The motivation for this research was to simplify and …

Electrochemical Detection Of Reactive Oxygen Species Via A Platinum Microelectrode Array, Victor M. Carriere Jr.

Master's Theses

Oxidative stress, an excess of endogenous or exogenous reactive oxygen species (ROS) in the body, is closely aligned with inflammatory responses. ROS such as hydrogen peroxide, superoxide, and radical hydroxyl ion serve essential functions in fighting infection, but chronic elevation of these species irreversibly damages cellular components. Given the central role of inflammation in a variety of diseases, including Alzheimer’s Disease, atherosclerosis, and rheumatoid arthritis, a low-cost, extracellular, non-invasive assay of ROS is needed.

This work reports the use of a platinum microelectrode array (Pt MEA)-based ceramic probe to detect time- and concentration-dependent variations in hydrogen peroxide (H2O2) production by …

Examining Jack Kerouac's Role In The Beat Generation: Exploring Place In On The Road And The Dharma Bums, Kimberly Ann Tucker

Master's Theses

This examination of two of Jack Kerouac’s roman-á-clefs, On the Road (1957) and The Dharma Bums (1958), illuminates characteristics of Kerouac’s personality and writing that are often ignored by current criticism. I will attempt to enhance current Kerouac scholarship by further analyzing the physical and spiritual journeys that Kerouac’s personas experience in these novels, contrasting Kerouac’s personas’ development with that of his Beat Generation companions. Despite his admiration for Dean Moriarty (Neal Cassady) and Japhy Ryder (Gary Snyder), Kerouac does not present these individuals as American heroes. Indeed, Kerouac’s cynical narration suggests that these Beat characters cannot offer him the …