Digital Commons Network^™

Out-Of-Core Gpu Path Tracing On Large Instanced Scenes Via Geometry Streaming, Jeremy Berchtold

Master's Theses

We present a technique for out-of-core GPU path tracing of arbitrarily large scenes that is compatible with hardware-accelerated ray-tracing. Our technique improves upon previous works by subdividing the scene spatially into streamable chunks that are loaded using a priority system that maximizes ray throughput and minimizes GPU memory usage. This allows for arbitrarily large scaling of scene complexity. Our system required under 19 minutes to render a solid color version of Disney's Moana Island scene (39.3 million instances, 261.1 million unique quads, and 82.4 billion instanced quads at a resolution of 1024x429 and 1024spp on an RTX 5000 (24GB memory …

Bearing Fault Detection And Classification Using Artificial Neural Networks, Harnak Singh

Master's Theses

Bearings are the essential components of modern rotating machines. Bearing faults can cause severe machine damages or even breakdowns.

In recent years, artificial intelligence and deep learning have been successfully applied to fault detection. In this thesis, convolutional neural networks (CNN) are employed for bearing fault detection and classification. Computer simulations results demonstrate that the CNN based approach is advantageous over the conventional regression model, with an overall accuracy of 99.5%.

Microgrid Laboratory Wind Energy Integration, Vincent Liang

Master's Theses

Cal Poly San Luis Obispo’s Electrical Engineering Department and the Power Energy Institute have developed a microgrid laboratory with various generators, loads, and protection systems over the past several years. To improve and make the Cal Poly microgrid laboratory more realistic, this thesis outlines the process of improving the EE microgrid setup by adding a wind energy generation system via an induction generator, excitation capacitors, and a protection relay. By adding an induction generator, the microgrid system becomes more resilient to sudden power fluctuations by maintaining a stable voltage and frequency when the microgrid is islanded. To test this, a …

Effects Of Experimental Scale On The Adsorption Of Two Pharmaceutical Drugs Detected In Municipal Wastewater Effluent, Michael Moore

Master's Theses

Pharmaceutical drugs are being produced and consumed in increasing quantities every year and are poorly treated by conventional wastewater treatment processes, leading to increasing detection of such compounds in surface water, groundwater, and municipal drinking water. Soil aquifer treatment (SAT) is a promising method for treating these emerging compounds through combined adsorption and degradation of target compounds in soil. This thesis examines the consistency of results from typical studies like adsorption isotherms and soil columns utilized in analysis of SAT performance, across varying experimental scales. The adsorption behavior of two pharmaceuticals was investigated as a function of experimental scale and …

Low-Cost Uav Swarm For Real-Time Object Detection Applications, Joel Valdovinos Miranda

Master's Theses

With unmanned aerial vehicles (UAVs), also known as drones, becoming readily available and affordable, applications for these devices have grown immensely. One type of application is the use of drones to fly over large areas and detect desired entities. For example, a swarm of drones could detect marine creatures near the surface of the ocean and provide users the location and type of animal found. However, even with the reduction in cost of drone technology, such applications result costly due to the use of custom hardware with built-in advanced capabilities. Therefore, the focus of this thesis is to compile an …

Improving Relation Extraction From Unstructured Genealogical Texts Using Fine-Tuned Transformers, Carloangello Parrolivelli

Master's Theses

Though exploring one’s family lineage through genealogical family trees can be insightful to developing one’s identity, this knowledge is typically held behind closed doors by private companies or require expensive technologies, such as DNA testing, to uncover. With the ever-booming explosion of data on the world wide web, many unstructured text documents, both old and new, are being discovered, written, and processed which contain rich genealogical information. With access to this immense amount of data, however, entails a costly process whereby people, typically volunteers, have to read large amounts of text to find relationships between people. This delays having genealogical …

Model-Based Design Of An Optimal Lqg Regulator For A Piezoelectric Actuated Smart Structure Using A High-Precision Laser Interferometry Measurement System, Grant P. Gallagher

Master's Theses

Smart structure control systems commonly use piezoceramic sensors or accelerometers as vibration measurement devices. These measurement devices often produce noisy and/or low-precision signals, which makes it difficult to measure small-amplitude vibrations. Laser interferometry devices pose as an alternative high-precision position measurement method, capable of nanometer-scale resolution. The aim of this research is to utilize a model-based design approach to develop and implement a real-time Linear Quadratic Gaussian (LQG) regulator for a piezoelectric actuated smart structure using a high-precision laser interferometry measurement system to suppress the excitation of vibratory modes.

The analytical model of the smart structure is derived using the …

Design, Fabrication, And Testing Of Mechanical Hinges With Snap-Fit Locking Mechanisms In Rigid Origami Structures, Colby James Scanlon

Master's Theses

The ancient art of ‘origami’ has recently become the source of inspiration for engineers to create structures that can unfold from a compact state to a fully deployed one. For instance, researchers have currently adopted origami designs in various engineering disciplines, including aerospace engineering, robotics, biomedical engineering, and architecture. In particular, architects have been interested in designing origami-inspired rigid walled structures that can be deployed as disaster-relief shelters. This type of design has three main advantages: transportability, constructability, and rigidity. Although there has been increased interests in deployable structures, limited research has been conducted on evaluating their structural performance, specifically …

Viability And Implementation Of A Vector Cryptography Extension For Risc-V, Jonathan W. Skelly

Master's Theses

RISC-V is an open-source instruction-set architecture (ISA) forming the basis of thousands of commercial and experimental microprocessors. The Scalar Cryptography extension ratified in December 2021 added scalar instructions that target common hashing and encryption algorithms, including SHA2 and AES. The next step forward for the RISC-V ISA in the field of cryptography and digital security is the development of vector cryptography instructions.

This thesis examines if it is viable to add vector implementations of existing RISC-V scalar cryptography instructions to the existing vector instruction format, and what improvements they can make to the execution of SHA2 and AES algorithms. Vector …

X-Band Rf Transmitter Design For Multi-Purpose Small Satellite Communication Operations, Omer F. Gumus

Master's Theses

This thesis provides a description of the analysis, design, and tests of an X-band RF Transmitter communication system for small satellites. X-band transmitter systems are becoming popular in the upcoming deep space missions. Most of the deep-space ground stations have been using X-band frequencies to receive or transmit signals. The X-band (<10 GHz) can offer lower atmospheric losses and up to a couple of Mbps data rates for multiple satellite operations. Nowadays, many small satellites have been using frequency bands such as VHF, UHF, L, and S-band frequencies for communication. From deep space to the ground station, the low-frequency ranges are inadequate in providing Mbps level data rates and enough bandwidth for deep space missions.

The main focus of this thesis was the development of the subsystems such as gain block amplifier, Mixer, Bandpass Filter, and RF power amplifier. The subsystems were designed separately, then they were connected together to perform an end-to-end system test. One of the thesis aims is to design …

Strainer: State Transcript Rating For Informed News Entity Retrieval, Thomas M. Gerrity

Master's Theses

Over the past two decades there has been a rapid decline in public oversight of state and local governments. From 2003 to 2014, the number of journalists assigned to cover the proceedings in state houses has declined by more than 30\%. During the same time period, non-profit projects such as Digital Democracy sought to collect and store legislative bill and hearing information on behalf of the public. More recently, AI4Reporters, an offshoot of Digital Democracy, seeks to actively summarize interesting legislative data.

This thesis presents STRAINER, a parallel project with AI4Reporters, as an active data retrieval and filtering system for …

Accelerating Graphics Rendering On Risc-V Gpus, Joshua Simpson

Master's Theses

Graphics Processing Units (GPUs) are commonly used to accelerate massively parallel workloads across a wide range of applications from machine learning to cryptocurrency mining. The original application for GPUs, however, was to accelerate graphics rendering which remains popular today through video gaming and video rendering. While GPUs began as fixed function hardware with minimal programmability, modern GPUs have adopted a design with many programmable cores and supporting fixed function hardware for rasterization, texture sampling, and render output tasks. This balance enables GPUs to be used for general purpose computing and still remain adept at graphics rendering. Previous work at the …

Unique Signed Minimal Wiring Diagrams And The Stanley-Reisner Correspondence, Vanessa Newsome-Slade

Master's Theses

Biological systems are commonly represented using networks consisting of interactions between various elements in the system. Reverse engineering, a method of mathematical modeling, is used to recover how the elements in the biological network are connected. These connections are encoded using wiring diagrams, which are directed graphs that describe how elements in a network affect one another. A signed wiring diagram provides additional information about the interactions between elements relating to activation and inhibition. Due to cost concerns, it is optimal to gain insight into biological networks with as few experiments and data as possible. Minimal wiring diagrams identify the …

Aac And Multilingualism In Children With Complex Communication Needs: Perspectives Of Filipino Parents And Teaching Professionals, Anne Aubrey V. Dulay

Master's Theses

Parents and teaching professionals of children who use augmentative and/or alternative communication (AAC) systems within multilingual environments often face complicated decisions regarding their language choices and practices. Understanding parents’ and teaching professionals’ perceptions on this topic can assist AAC service providers in supporting them better during intervention. This study aimed to explore the perceptions of Filipino parents and teaching professionals regarding AAC and multilingualism. Specifically, this study sought to describe parents’ and teaching professionals’ language choices and practices when interacting with the AAC communicator and to describe the factors that influence their language choices and practices. This study followed a …

Unmasking Medical Fake News Using Machine Learning Techniques, Garima Chaphekar

Master's Theses

Fake news has always been a critical and challenging problem in the informationenvironment. The propagation of false news is a serious concern, especially in medical information, which can have dangerous and potentially deadly consequences. With the tsunami of online misinformation, it is crucial to fight fake medical news. In this study, we use machine learning techniques to help detect fake news related to diseases, including COVID-19, Ebola, Zika, SARS, Cancer, and Polio. To facilitate research in this space, we create a new medical dataset named MedHub. MedHub has records from two publicly available datasets on COVID and manually curated facts …

Steric Effect On Benzyl Ether Olefines Under Sadmet Polymerization, Su Hu

Master's Theses

Acyclic diene metathesis (ADMET) polymerization, a type of olefin cross metathesis, is a step-growth and condensation polymerization that can be used to synthesize hydrocarbon polymers with diverse functional groups. Traditional ADMET with symmetric α,ω-dienes is not selective and can only form homopolymers or statistical copolymers. Changing to monomers with acrylate functional groups allows selective reactivity to form block and alternating polymers. In this project, we want to explore other functional groups that result in selective reactivity to form advanced polymer architectures via what we have termed selective acyclic diene metathesis (SADMET) polymerization. Developing new functionalized monomers for SADMET polymerization allows …

Fragmentation Drives Dominant Plant Encroachment On A Horizontal Wastewater Treatment Levee, Joia S. Fishman

Master's Theses

Urban coastal wetlands protect humans from sea-level rise while providing valuable habitat for wildlife. Degradation and loss of these wetlands threaten urban infrastructure such as wastewater treatment facilities. Nature-based adaptive solutions with the combined purposes of bioremediation, coastal defense, and habitat creation are being tested to make communities safer and more resilient. The current research examines a 6-year-old experimental horizontal levee at the Oro Loma Sanitary District in San Lorenzo, California. Using horizontal transects and quadrat sampling, I compare the success of two planting strategies – a wet meadow and a riparian scrub community – on an ecotone slope. I …

Mechanical Stabilization By Cyclic Compression Of Composite Polymer Electrolytes For Lithium-Ion Batteries, Nishad Mulay

Master's Theses

Composite polymer electrolytes (CPEs) for lithium-ion batteries provide an effectivebalance of ionic conductivity, mechanical robustness, and safety. Loss of charge capacity, however, is caused by multiple contributing factors, such as dendrite formation, changes in polymer crystallization, and reconfiguration of porous electrodes. In this thesis we specifically examine mechanical changes in the composite electrolyte layer. The hypothesis of this investigation is that the addition of rigid particles to a polymer electrolyte counteracts the fatigue softening effect caused by cyclic dimensional changes, as would be experienced during charge and discharge cycles. We apply cyclic compression to mimic stress cycling that is caused …

The Spatial Distribution Of Mercury Contamination In The Yolo Bypass, California, Thomas S. Mykytyn

Master's Theses

Gold and mercury mining in the latter half of California’s 19th century resulted in massive and lingering alterations to downstream ecosystems through sedimentation and mercury contamination. Located at the confluence of Sierra Nevada and Coast Range watersheds, the Yolo Bypass is a critical conveyor of flood waters from the Lower Sacramento Valley to the Sacramento–San Joaquin Delta. Sedimentation in the bypass diminishes its flood conveyance capacity, and Hg contamination is hazardous to humans and ecosystems. The purpose of this study is to locate and quantify mercury contamination in the Yolo Bypass. Concentrations of total mercury ([THg]) were measured in 22 …

Achieving Location Privacy In Ios Platform Using Location Privacy Framework, Anna Systaliuk

Master's Theses

Rising popularity of location-services mobile applications and geotagging digitalactivities resulted in astonishing amount of mobility data collected from user devices, raising privacy concerns regarding the way this data is extracted and handled. Despite numerous studies concluded that human location trace is highly unique and poses great re-identification risks, modern mobile operating systems fell short of implementing granular location access mechanism. Existing binary location access resulted into location-based-services being able to retrieve precise user’s coordinates regardless of how much details their functionality actually require and sell it to data brokers. This paper aims to provide practical solution how a mobile operating …

Comparative Study Between The Creep And Shrinkage Prediction Models, Abdulla Tahsin

Master's Theses

Seven creep and shrinkage prediction models (ACI 209R-92, B3, B4, CEB MC 90-99, fib MC2010, AASHTO 2020, GL 2000) have been evaluated using five statistical methods. The statistical methods utilized in this study are the residual method, including the average and the standard deviation of the residual, the CEB mean deviation MCEB, the CEB mean square error FCEB, the CEB coefficient of variation VCEB, and the modified coefficient of variation method ωm. The study utilized the RILEM and NU-ITI databases. Results show that the ACI 209R-92 and the B3 Models produced the most accurate creep and shrinkage predictions compared to …

Smartrec - A Smart Conversational Recommendation System Using Semantic Knowledge Graphs, Sudha Vijayakumar

Master's Theses

CRS strives to return the most relevant recommendations to users through a multi-turn interactive conversation. The Covid-19 pandemic has undoubtedly accelerated the pace of adoption of conversational AI systems by many online platforms needing to provide highly available customer support. This ongoing demand calls for the need to implement more generic and efficient conversational agents and recommendation engines that can provide customers with the required information at every stage of the user’s interaction with the e-commerce platform. This study presents a Smart Conversational AI-based recommendation system - SMARTREC, which enables a multi-turn conversation with the user to understand the context …

Optimization Of Cmos At Deep Cryogenic Temperatures, Prabjot K. Dhillon

Master's Theses

Cryogenic CMOS is a sought-out technology because of its applications to fields like quantum computing and deep space exploration. Though slight advancements have been made within the field of cryogenic CMOS technology, there persists critical challenges that need to resolve to further advance the field. Hence, there is a need to solve challenges like understanding the undesirable effects due to the device physics at cryogenic temperatures such as high threshold voltage, kink-effects, abnormal subthreshold swing etc. and developing reliable circuit models because many rely on analytical modeling. The research models a NMOS ON-current and subthreshold slope at temperatures of 300K …

Buried Treasure In San Francisco’S Golden Gate Park: Changing Tastes In The Twentieth Century As Seen Through The Music Of The Golden Gate Park Concert Band, Nathaniel L. Pergamit

Master's Theses

Buried deep under the Spreckels Temple of music, the bandstand In San Francisco’s Golden Gate Park, lay a treasure trove of sheet music and concert programs belonging to the Golden Gate Park Concert Band. This band, which has delighted audiences and park-goers in San Francisco for 140 years, had over a thousand scores and programs each waiting to be archived and preserved. From documents marked “Property of the WPA,” to handwritten letters from composers, to photographs of since forgotten events, these newly archived materials detail historic trends that shed light on San Francisco’s unique civic culture. Along with conventional critical …

Impact Of Climate Variability On Child Nutrition In Ethiopia, Juan S. Gomez

Master's Theses

Changes in precipitation and temperature due to climate change have caused a shortage in food productivity leading to an increase in malnutrition outcomes, especially among children in developing countries that are more susceptible to undernutrition outcomes. This study contributes to existing literature studying the impact of climate variability measured by temperature, precipitation, and vegetation index on wasting. Wasting is measured by the weight for height score during the main growing season (Meher) using Demographic and Health Surveys data for five different periods in Ethiopia. Results suggest that lower NDVI outcomes are associated with an increase in the risk of acute …

It Could Be “Win-Win”: The Us-China Bilateral Relationship, Xiaying Huang

Master's Theses

The bilateral relationship between the United States and China is crucial for international relations since these two great power states will influence the global economy, politics, and security. However, the US-China bilateral relationship has not always been stable and peaceful. The trade war was current issue to make the relationship between the two countries tenser and tenser. On the US side, the trade war was thought to promote domestic production, but the reality was the opposite; the trade war just broke the bilateral relationship and provided no long-term advantages to the US economy. In March 2022, the U.S. restores tariffs …

The Experiences Of International Graduate Students From Latin America In Their Transition Of Graduating And Finding A Job In The United States, Natalia Hernandez

Master's Theses

The purpose of this thesis project is to conduct a qualitative phenomenological study to understand the lived experiences of international graduate students from Latin America in the United States as they transition from their studies to finding a full-time job in the United States. The most common themes mentioned in the different sections of the interviews were: the different dynamics in their identity, the benefits, and limitations of their status in the American context, and how their professional development and economy are impacted while being international graduate students from Latin America. Student service departments such as the Career Service department, …

The Gallery As A Site Of Convergence: The Role Of Creative Environments At Postsecondary Institutions, Jordán Francisco Sandoval

Master's Theses

Not enough research explores the role of creative environments at postsecondary institutions. In response, this qualitative research study focuses upon university galleries believing them to be exemplary artistic spaces within college campuses. Using a theoretical framework of place-consciousness, the researcher examined the functions of the Mary and Carter Thacher Gallery at the University of San Francisco (USF), paying close attention to the ways it engaged the academic community in terms of scholarship and instruction. Informed by grounded theory and phenomenology, this study interviewed five professors who integrated a gallery visit into their curriculum during the 2021-2022 academic year. Collecting these …

Trophic Ecology Of Sailfish Larvae In The Gulf Of Mexico: An Analysis Of Diet, Prey Availability, Prey Quality, And Influences On Larval Growth, April Hugi

Master's Theses

The Gulf of Mexico is an important early life habitat for billfishes, whose larvae experience high growth rates despite having highly specialized diets, limited foraging abilities, and oligotrophic offshore habitats. Variability in the recent growth of sailfish larvae was compared to environmental, spatial, diet, prey availability, and fatty acid metrics using data collected from near-surface waters in the northern Gulf of Mexico (2017 - 2019). Larvae exhibited a highly selective feeding strategy in early development and expanded their feeding niche to include larger prey items (calanoid copepods, larval fish) once they reached flexion. Sailfish larvae showed significant positive selection for …

The Rhetoric Of Blame: A Rhetorical Framing Analysis Of Othering And Blame In Historical Health Crises, Colin G. Cameron

Master's Theses

The United States’ response to the COVID-19 pandemic was hallmarked by blame rhetoric and fluid social and political expedience. However, the pervasiveness of othering and blame in contemporary pandemic discourse is perhaps consistent with the blame rhetoric of health crises throughout history. Using a rhetorical framing analysis approach, this study aims to explore the various elements of blame rhetoric embedded in newsprint media frames regarding historic infectious disease outbreaks. In doing so, this study investigates three case studies: the San Francisco smallpox outbreak of 1876, the Spanish Flu pandemic of 1918, and the AIDS crisis of the 1980s – 1990s. …