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2019

Theses/Dissertations

Master's Theses and Project Reports

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Full-Text Articles in Engineering

Cubesat Astronomy Mission Modeling Using The Horizon Simulation Framework, Alexander W. Johnson Sep 2019

Cubesat Astronomy Mission Modeling Using The Horizon Simulation Framework, Alexander W. Johnson

Master's Theses and Project Reports

The CubeSat Astronomy Network is a proposed system of multiple CubeSat spacecraft capable of performing follow-up observations of astronomical targets of interest. The system is intended to serve as a space-borne platform that can complement existing systems utilized for astronomical research by undergraduate and high school students. Much research and development work has been performed to develop model-based system engineering methodologies and products for CubeSat missions, including the Horizon Simulation Framework. The Horizon Simulation Framework enables the development of system models using the Extended Markup Language (XML), and its simulation program can generate system simulations over model-specified timespans. System requirements ...


Investigation Of The Under-Body Flow Field Of A Prototype Long-Range Electric Vehicle, Matthew P. Nguyen Sep 2019

Investigation Of The Under-Body Flow Field Of A Prototype Long-Range Electric Vehicle, Matthew P. Nguyen

Master's Theses and Project Reports

This thesis presents changes to the design of the Prototype Vehicles Laboratory (PROVE Lab) Endurance Car, an electric car intended to break the Guinness World Record for the single-charge range of an electric vehicle. The design range is 1609.34 km, however at the design velocity of 104.6 kph, the drag is 196 N; which requires more battery capacity than the 100 kWh maximum of the baseline model. With a fixed frontal area, drag reduction can come from lowered velocity or reduced CD. CD reduction is attempted in four ways: side skirts between the fenders, a raised ride height ...


Development Of A Tailored Flight Test Approach For Small Unmanned Aircraft Systems, Neil A. Wolfe, Neil A. Wolfe Sep 2019

Development Of A Tailored Flight Test Approach For Small Unmanned Aircraft Systems, Neil A. Wolfe, Neil A. Wolfe

Master's Theses and Project Reports

This document contains the details of a study conducted to determine an effective performance flight test approach specifically for small Unmanned Aircraft Systems (sUAS). This was done by taking proven procedures and documentation from the FAA and the Air Force for manned aircraft and tailoring them specifically for use with sUAS flight test programs. A ‘sUAS Flight Testing Handbook’ was created from the proceedings to aid commercial organizations and recreational developers conducting sUAS research without access to flight test experience. A performance flight test program was conducted with the AeroVironment RQ-20 Puma sUAS using the developed approach to verify that ...


Design Principles And Preliminary Testing Of A Micropropulsion Electrospray Thruster Research Platform, Will Alan Mcgehee Jul 2019

Design Principles And Preliminary Testing Of A Micropropulsion Electrospray Thruster Research Platform, Will Alan Mcgehee

Master's Theses and Project Reports

The need for micropropulsion solutions for spacecraft has been steadily increasing as scientific payloads require higher accuracy maneuvers and as the use of small form-factor spacecraft such as CubeSats becomes more common. Of the technologies used for this purpose, electrospray thrusters offer performance that make them an ideal choice. Electrosprays offer high accuracy impulse bits at low power and high efficiency, and have low volume requirements. Design choice reasoning and preliminary testing results are presented for two electrospray thruster designs. The first thruster, named the Demonstration thruster, is operated in atmospheric conditions and serves as a highly visible example of ...


The Effects Of Atomic Oxygen On Patch Antenna Performance And Lifetime, Max J. Barta Jul 2019

The Effects Of Atomic Oxygen On Patch Antenna Performance And Lifetime, Max J. Barta

Master's Theses and Project Reports

The space environment is a volatile and challenging place for satellites to survive in. For Low Earth Orbiting (LEO) satellites, atomic oxygen (AO) is a constant corrosive effect that degrades the outer surface of satellites over long durations. Atomic oxygen exists in the atmosphere between 180 and 675 km and has a relatively high energy at 4.5 eV, which allows AO to break molecular bonds in materials on the surfaces of spacecraft. As the number and complexity of CubeSat missions increase, there is an increased risk that AO degradation on commercial off the shelf parts (COTS), such as antenna ...


Implementation Of A Scale Semi-Autonomous Platoon To Test Control Theory Attacks, Erik Miller Jul 2019

Implementation Of A Scale Semi-Autonomous Platoon To Test Control Theory Attacks, Erik Miller

Master's Theses and Project Reports

With all the advancements in autonomous and connected cars, there is a developing body of research around the security and robustness of driving automation systems. Attacks and mitigations for said attacks have been explored, but almost always solely in software simulations.

For this thesis, I led a team to build the foundation for an open source platoon of scale semi-autonomous vehicles. This work will enable future research into implementing theoretical attacks and mitigations. Our 1/10 scale car leverages an Nvidia Jetson, embedded microcontroller, and sensors. The Jetson manages the computer vision, networking, control logic, and overall system control; the ...


Study Of Paper Microbial Fuel Cells For Use In On-Site Wastewater Testing, William A. Tolmasoff, William A. Tolmasoff Jun 2019

Study Of Paper Microbial Fuel Cells For Use In On-Site Wastewater Testing, William A. Tolmasoff, William A. Tolmasoff

Master's Theses and Project Reports

This study demonstrated a technique for fabricating simple, low-cost Paper Microbial fuel cells (PMFC’s) in the model of a previous study to, for the first time, produce voltage from wastewater effluent. The PMFC’s were created by stacking and gluing the main components of an MFC together: reservoir layer; anode; cation exchange membrane (CEM); air cathode. A wax printer was used to create the hydrophobic borders of the PMFC’s on filter paper, and graphite paint was applied to the paper to create the anode. The CEM’s considered were filter paper, wax, and Nafion, with Nafion being the ...


Evaluating Creative Choice In K-12 Computer Science Curriculum, Kirsten L. Mork Jun 2019

Evaluating Creative Choice In K-12 Computer Science Curriculum, Kirsten L. Mork

Master's Theses and Project Reports

Computer Science is an increasingly important topic in K-12 education. Ever since the "computing crisis" of the early 2000s, where enrollment in CS dropped by over half in a five year span, increasing research has gone into improving and broadening enrollment in CS courses. Research shows the importance of introducing CS at a young age and the need for more exposure for younger children and young adults alike in order to work towards equity in the field. While there are many reasons for disinterest in CS courses, studies found one reason young adults do not want to study CS is ...


A Framework For Bim Model-Based Construction Cost Estimation, Michael Clark Jun 2019

A Framework For Bim Model-Based Construction Cost Estimation, Michael Clark

Master's Theses and Project Reports

This thesis presents a framework to conduct a quantity take-off (QTO) and cost estimate within the Building Information Modeling (BIM) Environment. The product of this framework is a model-based cost estimating tool. The framework addresses the cost uncertainty associated with the detailed information defining BIM model element properties. This cost uncertainty is due to the lack of available tools that address detailed QTO and cost estimation using solely a BIM platform. In addition, cost estimators have little experience in leveraging and managing information within semantic-rich BIM models. Unmanaged BIM element parameters are considered a source of uncertainty in a model-based ...


Robot Navigation In Cluttered Environments With Deep Reinforcement Learning, Ryan Weideman, Ryan Dean Weideman Jun 2019

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

Master's Theses and Project Reports

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 ...


Implementation Of Multivariate Artificial Neural Networks Coupled With Genetic Algorithms For The Multi-Objective Property Prediction And Optimization Of Emulsion Polymers, David Chisholm Jun 2019

Implementation Of Multivariate Artificial Neural Networks Coupled With Genetic Algorithms For The Multi-Objective Property Prediction And Optimization Of Emulsion Polymers, David Chisholm

Master's Theses and Project Reports

Machine learning has been gaining popularity over the past few decades as computers have become more advanced. On a fundamental level, machine learning consists of the use of computerized statistical methods to analyze data and discover trends that may not have been obvious or otherwise observable previously. These trends can then be used to make predictions on new data and explore entirely new design spaces. Methods vary from simple linear regression to highly complex neural networks, but the end goal is similar. The application of these methods to material property prediction and new material discovery has been of high interest ...


Analysis Of The Effects Of Adaptive Ramp Metering On Measures Of Efficiency With A Proposed Framework For Safety Evaluation, Jacky Loh Jun 2019

Analysis Of The Effects Of Adaptive Ramp Metering On Measures Of Efficiency With A Proposed Framework For Safety Evaluation, Jacky Loh

Master's Theses and Project Reports

ABSTRACT

Analysis of Effects of Adaptive Ramp Metering on Measures of Efficiency with a Proposed Framework for Safety Evaluation

Jacky Loh

Adaptive ramp metering (ARM) is a widely popular intelligent transportation system (ITS) tool that boasts the ability to reduce congestion and streamline traffic flow during peak hour periods while maintaining a lower implementation cost than traditional methods such as freeway widening. This thesis explores the effectiveness of ARM implementation on an 18 mile segment of the Interstate 80 (I-80) corridor in the Bay Area residing in northern California. Smaller segments of this particular segment were analyzed to determine the ...


Smart Dc Wall Outlet Design With Improved Load Voltage Detection, Patrick Donovon Granieri Jun 2019

Smart Dc Wall Outlet Design With Improved Load Voltage Detection, Patrick Donovon Granieri

Master's Theses and Project Reports

A standard home in the United States has access to the 120V AC power grid for use with home appliances. Many electronics used at home are powered by a DC power supply, which loses energy in the conversion from AC power. The DC House project avoids any conversion between AC and DC by storing energy in batteries as DC power and supplying it directly to DC appliances. While AC systems feature a standardized output voltage, no such standard exists for DC systems. The Smart DC Wall Outlet solves this by automatically adjusting its output voltage to meet any required DC ...


Carbonate Chemistry Characterization In A Low-Inflow Estuary With Recent Seagrass Loss, Jolie Higgins Jun 2019

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

Master's Theses and Project Reports

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 ...


Designing A Simulator For An Electrically-Pumped Organic Laser Diode, Robert Hulbert Jun 2019

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

Master's Theses and Project Reports

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 ...


Effects Of Corrugations On Stiffness Properties Of Composite Beams For Structural Applications, Jane Xiao Jun 2019

Effects Of Corrugations On Stiffness Properties Of Composite Beams For Structural Applications, Jane Xiao

Master's Theses and Project Reports

Composites have high strength-to-weight ratios, which is particularly desired for applications with weight restrictions. Common composite materials such as carbon fiber reinforced plastic (CF) and fiber glass reinforced plastic (FG) were used in this research. While composite materials possess high stiffness and strength properties, the stiffness of composite laminates may be maximized by changing the geometry. By adding corrugations, the flexural stiffness is increased in one direction compared to the stiffness of a flat part with the same amount of material. Thus, stiffness increases without a change in weight. The primary goal of this research was to investigate the stiffness ...


A Homegrown Dsmc-Pic Model For Electric Propulsion, Dominic Charles Lunde Jun 2019

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

Master's Theses and Project Reports

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 Predictive Modeling Approach For Assessing Seismic Soil Liquefaction Potential Using Cpt Data, Jonathan Paul Schmidt Jun 2019

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

Master's Theses and Project Reports

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 ...


Atomic Oxygen Effects On Particulate Contamination And Short Beam Strength Of Carbon Composites, Marlee K. Litzinger Jun 2019

Atomic Oxygen Effects On Particulate Contamination And Short Beam Strength Of Carbon Composites, Marlee K. Litzinger

Master's Theses and Project Reports

In order to design a successful space system, the unique challenges of the space environment it will operate in must be considered during the design process. Atomic oxygen (AO) is a detrimental environmental effect found in Low Earth Orbit (LEO) that affects spacecraft surfaces by oxidizing and eroding material over time, particularly polymers. Carbon fiber/epoxy composites are a commonly used spacecraft material affected by AO exposure. Carbon composites are used as a structural material, such as on solar panels; their large surface area therefore is a potential contamination source to sensitive components. The Space Environments and Testing Lab at ...


A 3-Dimensional In Silico Test Bed For Radiofrequency Ablation Catheter Design Evaluation And Optimization, Carolyn Teng Jun 2019

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

Master's Theses and Project Reports

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 ...


Viewpoint Optimization For Autonomous Strawberry Harvesting With Deep Reinforcement Learning, Jonathon J. Sather Jun 2019

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

Master's Theses and Project Reports

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 ...


Surveying Underwater Shipwrecks With Probabilistic Roadmaps, Amy Jeannette Lewis Jun 2019

Surveying Underwater Shipwrecks With Probabilistic Roadmaps, Amy Jeannette Lewis

Master's Theses and Project Reports

Almost two thirds of the Earth's surface is covered in ocean, and yet, only about 5% of it is mapped. There are an unknown amount of sunken ships, planes, and other artifacts hidden below the sea. Extensive search via boat and a sonar tow fish following a standard lawnmower pattern is used to identify sites of interest. Then, if a site has been determined to potentially be historically significant, the most common next step is a survey by either a human dive team or remotely operated vehicle. These are time consuming, error prone, and potentially dangerous options, but autonomous ...


Atmospheric Water Harvesting: An Experimental Study Of Viability And The Influence Of Surface Geometry, Orientation, And Drainage, Carson T. Hand Jun 2019

Atmospheric Water Harvesting: An Experimental Study Of Viability And The Influence Of Surface Geometry, Orientation, And Drainage, Carson T. Hand

Master's Theses and Project Reports

Fresh water collection techniques have gained significant attention due to global dwindling of fresh water resources and recent scares such as the 2011-2017 California drought. This project explores the economic viability of actively harvesting water from fog, and techniques to maximize water collection. Vapor compression and thermoelectric cooling based dehumidifier prototypes are tested in a series of experiments to assess water collection capability in foggy environments, and what parameters can increase that capability. This testing shows an approximate maximum collection rate of 1.25 L/kWh for the vapor compression prototype, and 0.32 L/kWh for the thermoelectric cooling ...


The Performance Cost Of Security, Lucy R. Bowen Jun 2019

The Performance Cost Of Security, Lucy R. Bowen

Master's Theses and Project Reports

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 ...


A Comparison Of Water Main Failure Prediction Models In San Luis Obispo, Ca, Kyle Eric Aube Jun 2019

A Comparison Of Water Main Failure Prediction Models In San Luis Obispo, Ca, Kyle Eric Aube

Master's Theses and Project Reports

This study compared four different water main failure prediction models: a statistically simple model, a statistically complex model, a statistically complex model with modifications termed the 2019 model, and an age-based model. The statistically complex models compute the probability of failure based on age, size, internal pressure, length of pipe in corrosive soil, land use, and material of the. These two values are then used to prioritize a water main rehabilitation program to effectively use the municipality’s funds. The 2019 model calculates the probability of failure and consequence of failure differently than the statistically complex model by considering corrosive ...


Multiple Input, Single Output Dc-Dc Conversion Stage For Dc House, Jason Baltierrez Jun 2019

Multiple Input, Single Output Dc-Dc Conversion Stage For Dc House, Jason Baltierrez

Master's Theses and Project Reports

n this thesis project, a proposed architecture for the multiple input, single output conversion stage for the DC House was designed, simulated, and tested. This architecture allows for multiple different input sources to be used to create a single higher power output source. The design uses a DC-DC boost converter with a parallelable output which has been demonstrated to allow increased total output power as a function of the number of input sources available. The parallelable output has been shown to distribute load amongst the input sources relatively closely to optimize the system. This approach is also desirable since it ...


Analog Single Sideband-Pulse Width Modulation Processor For Parametric Acoustic Arrays, Vikrant A. Marathe Jun 2019

Analog Single Sideband-Pulse Width Modulation Processor For Parametric Acoustic Arrays, Vikrant A. Marathe

Master's Theses and Project Reports

Parametric acoustic arrays are ultrasonic-based loudspeakers that produce highly directive audio. The audio must first be preprocessed and modulated into an ultrasonic carrier before being emitted into the air, where it will self-demodulate in the far field. The resulting audio wave is proportional to the double time-derivative of the square of the modulation envelope. This thesis presents a fully analog processor which encodes the audio into two Pulse Width Modulated (PWM) signals in quadrature phase and sums them together to produce a Single Sideband (SSB) spectrum around the fundamental frequency of the PWM signals. The two signals are modulated between ...


Fifth Aeon - A.I Competition And Balancer, William M. Ritson Jun 2019

Fifth Aeon - A.I Competition And Balancer, William M. Ritson

Master's Theses and Project Reports

Collectible Card Games (CCG) are one of the most popular types of games in both digital and physical space. Despite their popularity, there is a great deal of room for exploration into the application of artificial intelligence in order to enhance CCG gameplay and development. This paper presents Fifth Aeon a novel and open source CCG built to run in browsers and two A.I applications built upon Fifth Aeon. The first application is an artificial intelligence competition run on the Fifth Aeon game. The second is an automatic balancing system capable of helping a designer create new cards that ...


Evaluation Of Tensile Properties For Selective Laser Melted 316l Stainless Steel And The Influence Of Inherent Process Features, Paul Swartz Jun 2019

Evaluation Of Tensile Properties For Selective Laser Melted 316l Stainless Steel And The Influence Of Inherent Process Features, Paul Swartz

Master's Theses and Project Reports

Optimal print parameters for additively manufacturing 316L stainless steel using selective laser melting (SLM) at Cal Poly had previously been identified. In order to further support the viability of the current settings, tensile material characteristics were needed. Furthermore, reliable performance of the as-printed material had to be demonstrated. Any influence on the static performance of parts in the as-printed condition inherent to the SLM manufacturing process itself needed to be identified. Tensile testing was conducted to determine the properties of material in the as-printed condition. So as to have confidence in the experimental results, other investigations were also conducted to ...


Cloneless: Code Clone Detection Via Program Dependence Graphs With Relaxed Constraints, Thomas J. Simko Jun 2019

Cloneless: Code Clone Detection Via Program Dependence Graphs With Relaxed Constraints, Thomas J. Simko

Master's Theses and Project Reports

Code clones are pieces of code that have the same functionality. While some clones may structurally match one another, others may look drastically different. The inclusion of code clones clutters a code base, leading to increased costs through maintenance. Duplicate code is introduced through a variety of means, such as copy-pasting, code generated by tools, or developers unintentionally writing similar pieces of code. While manual clone identification may be more accurate than automated detection, it is infeasible due to the extensive size of many code bases. Software code clone detection methods have differing degree of success based on the analysis ...