Digital Commons Network^™

The Performance Cost Of Security, Lucy R. Bowen

Master's Theses

Historically, performance has been the most important feature when optimizing computer hardware. Modern processors are so highly optimized that every cycle of computation time matters. However, this practice of optimizing for performance at all costs has been called into question by new microarchitectural attacks, e.g. Meltdown and Spectre. Microarchitectural attacks exploit the effects of microarchitectural components or optimizations in order to leak data to an attacker. These attacks have caused processor manufacturers to introduce performance impacting mitigations in both software and silicon.

To investigate the performance impact of the various mitigations, a test suite of forty-seven different tests was created. …

Effects Of Barotrauma On Four Species Of Pacific Rockfishes (Sebastes Spp.), Lesley Salter

Master's Theses

Physoclistic fish, such as Pacific rockfishes (genus Sebastes), have closed swim bladders that help them regulate their buoyancy. When anglers catch these fish and reel them to the surface, gases within their swim bladder expand due to the decrease in pressure. This can cause their swim bladder to over inflate––a condition known as barotrauma. Overly buoyant fish experiencing barotrauma often struggle to swim back to dwelling depth if released at the ocean’s surface. These fish may experience high rates of mortality by thermal shock caused by the warmer surface temperatures, starvation, predation, or vision problems caused by barotrauma. Assisted …

Robot Navigation In Cluttered Environments With Deep Reinforcement Learning, Ryan Weideman

Master's Theses

The application of robotics in cluttered and dynamic environments provides a wealth of challenges. This thesis proposes a deep reinforcement learning based system that determines collision free navigation robot velocities directly from a sequence of depth images and a desired direction of travel. The system is designed such that a real robot could be placed in an unmapped, cluttered environment and be able to navigate in a desired direction with no prior knowledge. Deep Q-learning, coupled with the innovations of double Q-learning and dueling Q-networks, is applied. Two modifications of this architecture are presented to incorporate direction heading information that …

Viewpoint Optimization For Autonomous Strawberry Harvesting With Deep Reinforcement Learning, Jonathon J. Sather

Master's Theses

Autonomous harvesting may provide a viable solution to mounting labor pressures in the United States' strawberry industry. However, due to bottlenecks in machine perception and economic viability, a profitable and commercially adopted strawberry harvesting system remains elusive. In this research, we explore the feasibility of using deep reinforcement learning to overcome these bottlenecks and develop a practical algorithm to address the sub-objective of viewpoint optimization, or the development of a control policy to direct a camera to favorable vantage points for autonomous harvesting. We evaluate the algorithm's performance in a custom, open-source simulated environment and observe affirmative results. Our trained …

Evaluating Projections And Developing Projection Models For Daily Fantasy Basketball, Eric C. Evangelista

Master's Theses

Daily fantasy sports (DFS) has grown in popularity with millions of participants throughout the world. However, studies have shown that most profits from DFS contests are won by only a small percentage of players. This thesis addresses the challenges faced by DFS participants by evaluating sources that provide player projections for NBA DFS contests and by developing machine learning models that produce competitive player projections.

External sources are evaluated by constructing daily lineups based on the projections offered and evaluating those lineups in the context of all potential lineups, as well as those submitted by participants in competitive FanDuel DFS …

A Case Study Examining The Structure Of The Event Process At California Polytechnic State University, Ryan R. Baker

Master's Theses

The purpose of this study was to examine the structure of the event process on Cal Poly’s campus. An intrinsic case study method was used, and data were collected and analyzed using triangulation from three sources of information: documents, interviews, and participation research. Overall, the structure of the event management process on campus was found to be stable, but could use improvement. Cal Poly should consider establishing a specific, designated organization that would help centralize the event management process at Cal Poly. This organization could be in charge of training and updating event managers, approving events, monitoring volume of events …

Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss, Jolie Higgins

Master's Theses

Estuaries are dynamic environments that are strongly affected by natural variability, as well as direct and indirect anthropogenic impacts. A better understanding of the drivers of carbon fluxes and biogeochemical variability in estuarine systems is needed, particularly with the increasing threat of ocean acidification. Morro Bay in Central California is a small nationally protected estuary, with seasonally low freshwater inputs. Since 2007, the bay has experienced a significant loss of native seagrass, Zostera marina, which is an important component of the marine ecosystem. Because seagrass photosynthesis decreases carbon dioxide and increases oxygen in the water column, the loss of seagrass …

A Predictive Modeling Approach For Assessing Seismic Soil Liquefaction Potential Using Cpt Data, Jonathan Paul Schmidt

Master's Theses

Soil liquefaction, or loss of strength due to excess pore water pressures generated during dynamic loading, is a main cause of damage during earthquakes. When a soil liquefies (referred to as triggering), it may lose its ability to support overlying structures, deform vertically or laterally, or cause buoyant uplift of buried utilities. Empirical liquefaction models, used to predict liquefaction potential based upon in-situ soil index property measurements and anticipated level of seismic loading, are the standard of practice for assessing liquefaction triggering. However, many current models do not incorporate predictor variable uncertainty or do so in a limited fashion. Additionally, …

Designing A Simulator For An Electrically-Pumped Organic Laser Diode, Robert Hulbert

Master's Theses

Organic semiconductors provide an alternative set of basis materials to fabricate electronic devices like PN Junctions, LEDs, and FETs. These materials have several benefits over traditional inorganic semiconductors including their mechanical flexibility, reliance on renewable resources, and inexpensive large-scale manufacturability. Despite the contemporary device implementations with organic semiconductors, a solid-state electrically-pumped organic laser diode does not exist. However, organically-based lasers do exist by utilizing the organic material strictly for optical gain. The challenge occurs when charge carriers appear in the organic material. The charge carriers must reach a concentration such that population inversion occurs producing optical gain. However, between the …

A Homegrown Dsmc-Pic Model For Electric Propulsion, Dominic Charles Lunde

Master's Theses

Powering spacecraft with electric propulsion is becoming more common, especially in CubeSat-class satellites. On account of the risk of spacecraft interactions, it is important to have robust analysis and modeling tools of electric propulsion engines, particularly of the plasma plume. The Navier-Stokes equations used in classic continuum computational fluid dynamics do not apply to the rarefied plasma, and therefore another method must be used to model the flow. A good solution is to use the DSMC method, which uses a combination of particle modeling and statistical methods for modeling the simulated molecules. A DSMC simulation known as SINATRA has been …

A 3-Dimensional In Silico Test Bed For Radiofrequency Ablation Catheter Design Evaluation And Optimization, Carolyn Teng

Master's Theses

Atrial fibrillation (AF) is the disordered activation of the atrial myocardium, which is a major cause of stroke. Currently, the most effective, minimally traumatic treatment for AF is percutaneous catheter ablation to isolate arrhythmogenic areas from the rest of the atrium. The standard in vitro evaluation of ablation catheters through lesion studies is a resource intensive effort due to tissue variability and visual measurement methods, necessitating large sample sizes and multiple prototype builds. A computational test bed for ablation catheter evaluation was built in SolidWorks® using the morphology and dimensions of the left atrium adjacent structures. From this geometry, the …

Observations Of The Copenhagen Networks Study, Michael A. Cantrell

Master's Theses

Attribute-rich longitudinal datasets of any kind are extremely rare. In 2012 and 2013, the SensibleDTU project created such a dataset using approximately 1,000 university students. Since then, a large number of studies have been performed using this dataset to ask various questions about social dynamics. This thesis delves into this dataset in an effort to explore previously unanswered questions. First, we define and identify social encounters in order to ask questions about face-to-face interaction networks. Next, we isolate students who send and receive disproportionately high numbers of phone calls and text messages to see how these groups compare to the …

Dynamic Response Validation Of Cubesats Through Testing And Finite Element Analysis, Peter Rivera

Master's Theses

During a rocket launch, satellites withstand large dynamic forces due to vibrations that are transmitted from the launch vehicle. As such, they must undergo testing to ensure that their function is not impaired by such forces. CubeSats are cost-effective nanosatellites, and like their larger counterparts, undergo dynamic testing for launch qualification. While dynamic analysis can done on a CubeSat alone, other assembly constituents also affect the response, and including them in the analysis can provide insight on the true dynamic behavior of CubeSats. To show this, the work presented here recreates a vibration test setup using Finite Element Analysis (FEA) …

Development Of A Model And Imbalance Detection System For The Cal Poly Wind Turbine, Ryan Miki Takatsuka

Master's Theses

This thesis develops a model of the Cal Poly Wind Turbine that is used to determine if there is an imbalance in the turbine rotor. A theoretical model is derived to estimate the expected vibrations when there is an imbalance in the rotor. Vibration and acceleration data are collected from the turbine tower during operation to confirm the model is useful and accurate for determining imbalances in the turbine.

Digital signal processing techniques for analyzing the vibration data are explored and tested with simulation data. This includes frequency shifts, lock-in amplifiers, phase-locked loops, discrete Fourier transforms, and decimation filters. The …

Snoring: A Noise Defect Prediction Datasets, Aalok Ahluwalia

Master's Theses

Defect prediction aims at identifying software artifacts that are likely to exhibit a defect. The main purpose of defect prediction is to reduce the cost of testing and code review, by letting developers focus on specific artifacts. Several researchers have worked on improving the accuracy of defect estimation models using techniques such as tuning, re-balancing, or feature selection. Ultimately, the reliability of a prediction model depends on the quality of the dataset. Therefore effort has been spent in identifying sources of noise in the datasets, and how to deal with them, including defect misclassification and defect origin. A key component …

The Investigation Of Methylidyne Radical (Ch) Reactions With Furan, 2-Methylfuran, And 2,5-Dimethlyfuran And The Photoionization And Photodissociation Of Valeric Acid, Erica Carrasco

Master's Theses

This thesis presents the combustion study of three furanic compounds using synchrotron radiation coupled with multiplexed photoionization mass spectrometry at 298 K. The experiments were performed at the Chemical Dynamics Beamline 9.0.2 at the Advanced Light Source of the Lawrence Berkeley National Laboratory. The reactions of the three furanic compounds with methylidyne (CH) radicals were analyzed based on their photoionization spectra and kinetic profiles.

Additionally, the unimolecular dissociation of valeric acid was also studied and presented in this work using the double imaging photoelectron photoion spectrometry (i2PEPICO) coupled with synchrotron radiation from the VUV beamline. The experiments were carried out …

Synchrotron Photoionization Study Of 2,5-Dimethylfuran Oxidation Initiated By O(3p) Atoms, And Computational Studies Of Superalkali Species: Li3f2, Heejune Park

Master's Theses

This thesis presents the experimental study of a 2,5-dimethylfuran oxidation reaction initiated by atomic oxygen (O(³P)) and the theoretical investigation of superalkalis properties. The experiments were performed at the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source (ALS) located at the Lawrence Berkeley National Laboratory in Berkeley, CA. The first chapter discusses world energy consumption and progress towards new sustainable energy sources, mainly focusing on biofuels, along with a basic description of combustion. A description of the superalkalis and a brief history of synchrotron radiation are also presented in Chapter 1. Chapter 2 describes the components of …

Competition And Cooperation In Polygynous & Monogamous Households: Experimental Evidence From Sierra Leone, Bethany Gerdemann

Master's Theses

Competition and cooperation in polygynous households have both been widely documented across various disciplines. There is contradictory evidence as to whether these interpersonal dynamics produce better or worse outcomes for the household. This study uses a competitiveness game and a series of dictator games to measure competition and cooperation within households and between marriage types. Results show that there are key differences between monogamy and polygyny. Monogamous women compete less with their husbands than stranger and less in comparison to polygynous women. Monogamous spouses are more likely to forgo economic opportunities than polygynous spouses and have a greater preference for …

Seizure Detection Using Teager-Kaiser Energy And A Channel Signal Quality Assessment Algorithm, Samuel Clary

Master's Theses

This study investigated the possibility of reducing the time required for accurate epileptic seizure detection through a retroactive analysis. Epilepsy is a neurological disorder affecting over 50 million individuals globally and is defined as a disorder which results in two seizures unprovoked by fever or medication. Diagnosis of epilepsy typically involves a monitored stay at an Epilepsy Monitoring Unit (EMU). The monitoring and diagnosis process ranges on average from $35,000 to $40,000 for a single stay, and the patient results from EMU are not instantly available to the patient. The collected electroencephalogram (EEG) must be analyzed by a trained EMU …

The Real-Time Application Of Control Theory To Pharmacokinetics, George W. Carpenter Iii

Master's Theses

An optically-based injection control system has been developed as a proof-of- concept that such is of use for an intravenous drug delivery application. Current clinical drug delivery for oncology typically provides for intravenous administration without providing awareness of achieved plasma concentration, yet interpatient variability produces consequences ranging from toxicity to ineffectual treatments. We report a closed loop injection system integrating a pulse-photoplethysmograph to measure the concentration of indocyanine green (ICG) in the circulating blood of a one-compartment murine model. A proportional-derivative (PD) controller manages the injection rate in real-time. The target function for the controller is the population estimate of …

The Long-Run Effects Of Tropical Cyclones On Infant Mortality, Isabel Miranda

Master's Theses

In the United States alone, each tropical cyclone causes an average of $14.6 billion worth of damages. In addition to the destruction of physical infrastructure, natural disasters also negatively impact human capital formation. These losses are often more difficult to observe, and therefore, are over looked when quantifying the true costs of natural disasters. One particular effect is an increase in infant mortality rates, an important indicator of a country’s general socioeconomic level. This paper utilizes a model created by Anttila-Hughes and Hsiang, that takes advantage of annual variation in tropical cyclones using annual spatial average maximum wind speeds and …

The Behavioral Determinants Of Well-Being In Sierra Leone, Madison Levine

Master's Theses

Ensuring the needs of individuals are met leads to a more prosperous economy. Healthy economic activity is dependent on a supported community of people. These people express different levels of happiness depending on where they come from and make behavioral choices every day influenced by their association with their community. Currently most subjective data have come from western educated industrialized rich and democratic (WEIRD) areas. These results are placed as generalizations across all other countries and are not giving an adequate representation of well-being for the population in non-WEIRD areas. Our study outlines an in-depth survey covering subjective well-being measurements …

Facilitating Greenhouse Gas Reduction And Climate Change Adaptation Within The Coastal Zone: A Policy Analysis For The California Coastal Commission, Nicole Young

Master's Theses

California is already experiencing impacts to its coastline due to climate change, and more severe impacts are anticipated if greenhouse gas emissions continue to rise. These climate change impacts are especially strong within the California coastal zone, which falls under the jurisdiction of the California Coastal Commission. The Commission has a history of rigorous environmental protection and is committed to protecting California’s coast through proactive planning and regulation, however they will need to initiate coastal policies with ambitious targets to facilitate effective climate change adaptation and mitigation. This study analyzed existing California climate policies and Coastal Commission policies to identify …

Wildfire Exposure To Critical Habitat Of Endangered And Threatened Species In California, Kristin Butcher

Master's Theses

Researchers, fire ecologists and wildlife managers are concerned about impact to endangered and threatened species and their critical habitat due to the projected increase in future wildfires. Wildfires have been studied in California for the last six decades and have been increasing at an alarming rate since the 1980’s. In this study, I use the 2018 spatial dataset for critical habitat of federally endangered and threatened species located in the state boundaries of California and compare it to a spatial dataset for wildfires that have occurred over the span of 32 years (1984 to 2016). Trends are derived from spatial …

Bridging The Gender Gap: Women In Stem Management, Kathryn Skeeters

Master's Theses

The purpose of this thesis is to study the current effects of training and accommodations on women in the Science, Technology, Engineering, and Math fields. Currently, there is a lack of women at the senior levels in the STEM field. This study evaluates the current literature as well as the personal experiences of 14 subjects. This information was collected through interviews. No personal data besides gender and age is communicated in the paper, with company names and signifiers removed. With the information gleaned from this research, the study evaluates the current programs and assesses a path forward. The assumption from …

Reachability Analysis Of Power Electronic Converters, Heqiang Wang

Master's Theses

This work presents a reachability analysis approach for dual active bridge (DAB) converters in the presence of heterogeneous uncertainties induced by manufacturing tolerance, temperature, humidity, etc. Reachability analysis can overapproximate the set of all possible reachable states from the set of initial states and parameter values based on the reachability algorithm. The novelty of this work includes: 1) it gives a comprehensive introduction of how to build a hybrid automata model for a DAB converter, and use the hybrid automata model for the purpose of reachability analysis through SpaceEx; 2) it develops the procedures of building the SpaceEx model for …

The Challenging Experiences Of The Graduate Mathematics Teaching Assistant, Zoe Cramer

Master's Theses

This study investigates the challenges that beginning graduate mathematics teaching assistants (MTAs) face and suggests possible solutions to aid in their transition to teaching. Interviews and surveys were conducted with both beginning and experienced MTAs to better understand their experiences.

The Temperature-Dependent Mechanics Of Human Articular Cartilage Under Large-Strain Shear, Lauren Marshall

Master's Theses

Articular cartilage is a soft tissue that facilitates joint movement and protects bone contact surfaces. Human articular cartilage sees a range of temperatures in vivodepending on external thermal conditions. Researchers recently demonstrated that cartilage dissipates energy during physiological loading to elevate the temperature to enhance cell viability. Despite these important insights, researchers often consider the knee isothermal, thus the large deformation mechanical response under transient thermal conditions remains largely unknown. We aimed to quantify the mechanical responses at 24°C, 40°C, 70°C, and 24°C repeated, and apply our data to determine whether the mechanical responses of cartilage vary within the …

Exploring Uncertainty In Real-Time Hybrid Substructuring, Connor H. Ligeikis

Master's Theses

Real-time hybrid substructuring (RTHS) is a cyber-physical vibration testing method that partitions a structural system into numerical and physical substructures. RTHS incorporates sensing, actuation, and computing technologies to couple these substructures in real time. RTHS can be used to realistically examine the performance of structural systems with rate-dependent structural components that may be difficult to accurately model. However, uncertainty can be found in many aspects of RTHS testing including noise in sensor measurements, actuator performance and tracking, non-linearities in the physical test specimen, and numerical modeling assumptions. In the numerical substructure, uncertainty in material properties, stiffness, damping, or geometry may …

Performance Comparison Of Alternative Representations Of Traffic Volume In Safety Performance Functions For Rural Road Intersections, Unica Khadka

Master's Theses

No abstract provided.