Engineering Commons^™

Aeroelastic Analysis Of Small-Scale Aircraft, Kent Roberts

Master's Theses

The structural design of flight vehicles is a balancing act between maximizing loading capability while minimizing weight. An engineer must consider not only the classical static structural yielding failure of a vehicle, but a variety of ways in which structural deformations can in turn, affect the loading conditions driving those deformations. Lift redistribution, divergence, and flutter are exactly such dynamic aeroelastic phenomena that must be properly characterized during the design of a vehicle; to do otherwise is to risk catastrophe. Relevant within the university context is the design of small-scale aircraft for student projects and of particular consideration, the DBF …

Underground Transmission For Renewable Energy: Design, Modeling, And Analysis, Matthew Suen

Master's Theses

A microgrid is a local energy grid that could be disconnected from the larger grid and operate autonomously. This particular segment of the power industry is growing due to its reliability during times of emergency and crisis. Among these benefits are improved efficiency, lower operating costs, renewable generation sources, and improved resiliency of the regional electric grid. Communities can better prepare for unprecedented weather like wildfires, hurricanes, and other natural disasters. Regions that produce renewable energy can export their surplus through high voltage transmission lines to balance power supply and demand needs.

This Underground High-Voltage Transmission Network project aims to …

Effect Of Indentation On Sandwich Composite Structure Mechanical Behavior, Marius V. Jatulis

Master's Theses

Composite sandwich structures are prevalent in engineering applications where high strength to weight ratios are critical. A composite sandwich includes the addition of a core material between two composite face sheets to increase ultimate stress in compression and bending loading cases. The performance of many composite sandwich structure configurations is well understood in the undamaged case. This analysis examines a type of damage, low velocity indentation, and determines the effect on mechanical behavior. The scope of the analysis includes manufacturing sandwich composite structures, creating indentation in the composite, and testing the sandwich composite structure. The mechanical behavior of the composite …

System Performance Model And Control System For A Small-Scale Horizontal Axis Wind Turbine, Niko Banks

Master's Theses

Predicting the performance of wind turbines is a key part of the turbine design process and operation, as predictive models play a large role in determining potential power output and efficiency at different operating conditions to help maximize production. On small-scale wind turbines performance models become more complex, as the rotor aerodynamic performance depends not only on the tip speed ratio, but also on the flow Reynolds number. An accurate predictive model that includes this behavior on small-scale wind turbines can be used to find the optimal operating conditions for power output, and is also a critical component of the …

Evaluation Of Cost-Effective Alternative Designs For Rural Expressway Intersections, Jonathan Howard

Master's Theses

Despite numerous studies demonstrating the effectiveness of Restricted Crossing U-Turn (RCUT) intersection design, its implementation remains uneven and close to zero in some large states such as California. This research provides a comprehensive framework to estimate the operational and safety performance of future RCUT designs in California. The framework is demonstrated for five intersections located on high-speed rural expressways in California using VISSIM microsimulation models to measure operational performance for each intersection including the base condition with the existing Two-Way Stop-Controlled (TWSC) intersection and two RCUT designs. To evaluate future safety performance, the microsimulation models were further utilized to compile …

The Design, Construction And Analysis Of A Large Round Bale Handling Implement, Garrett J. Forbes

Master's Theses

To entice a small-scale hay producer to purchase equipment that will improve their hay hauling operation, a more cost effective and more universal solution must be developed. The objectives of this project are to develop and test a prototype large round bale handler. The prototype was built to industry standards, using modern electronic controls and the latest design and fabrication methods. The prototype makes use of an existing trailer and by doing so can be a less expensive method of hauling hay when compared to other equipment currently on the market. While the combination of the prototype bale handler and …

Investigation Of Green Strawberry Detection Using R-Cnn With Various Architectures, Daniel W. Rivers

Master's Theses

Traditional image processing solutions have been applied in the past to detect and count strawberries. These methods typically involve feature extraction followed by object detection using one or more features. Some object detection problems can be ambiguous as to what features are relevant and the solutions to many problems are only fully realized when the modern approach has been applied and tested, such as deep learning.

In this work, we investigate the use of R-CNN for green strawberry detection. The object detection involves finding regions of interest (ROIs) in field images using the selective segmentation algorithm and inputting these regions …

Impact Of Teaching Practices And Communication Climates On Participation In Computer Science Education, Jackie Krone

Master's Theses

One way to understand teaching is to view it as a people process rather than a presentation of knowledge. It follows that the role of an educator often extends beyond the primary subject matter and into the realm of classroom management. With this in mind, our research aimed to capture the various teaching practices, participation patterns, and communication climates that occur in virtual computer science classrooms. We sought to answer the following research questions related to virtual computer science classrooms at our institution: Who participates in virtual computer science classrooms, and is participation proportional to student demographics? Is there any …

Integration Of Electrical Impedance Spectroscopy For Multichannel Cell Culture Measurement, Conard Chan

Master's Theses

ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY (EIS) has been widely used to study the electrical properties of biological material due to its non-invasive nature and experimental reliability. However, most of the precision impedance analyzers used in EIS only provide single- or two-channel measurements which are inadequate for larger-scale multiplexed measurements, such as those found in modern microfluidic cell culture experiments. The Biomedical Microsystems Laboratory has developed a 16-channel cell culture platform with integrated electrode arrays for monitoring cell growth and electrical properties (i.e., the so-called “electrical phenotype”). In this paper, a system consisting of a 16-channel solid-state analog multiplexer (MUX)paired with a low-cost, …

Characterization, Design, And Optimization Of Dual-Purpose Wind Turbines And Frost Protection Fans, Ethan Narad

Master's Theses

This thesis report outlines the creation of a MATLAB tool to design reversible machines that can function as both wind turbines and as agricultural frost protection fans. Frost protection fans are used to prevent crop loss during radiative freeze events during which a temperature inversion is present. Such a dual-purpose machine fundamentally has the constraint that it must use symmetric airfoils, so a suite of tools for automatically designing an optimized wind turbine blade with symmetric airfoils using the Blade Element Momentum (BEM) theory approach is presented. The BEM code is then re-derived and adapted for use with a frost …

An Analysis Of Thermal Comfort Perception In Cal Poly's Math & Science Building, Pouria Ali Fariborzi

Master's Theses

Since Americans, on average, spend approximately 90% of their time indoors according to the EPA, it is crucial to provide room occupants with the best, most comfortable, and healthiest possible environment, which is known as Indoor Environmental Quality (IEQ). This thesis aims to identify how we can provide comfortable learning environments to improve student success. To determine the best possible environment for occupants, a model of the Math & Science Building was developed, validated, and modified using DesignBuilder. In addition, we compared thermal comfort surveys to actual measured conditions for some classrooms. Analysis indicates that students prefer a cooler thermal …

Medial And Lateral Tibiofemoral Contact Forces For Individuals With High Body Mass Index In Gait And Cycling Training, Reymil Fernandez

Master's Theses

The prevalence of knee osteoarthritis, a degenerative joint disease characterized by the degradation of articular cartilage, is correlated with the rise in obesity. The rising rates of obesity in children and adults highlight the need for identifying a sustainable physical activity that promotes fitness while mitigating initiation and progression of osteoarthritis. The objective of this study was to determine an effective rehabilitation and lifelong fitness sustainment exercise regimen that minimize risk of osteoarthritis in individuals with high body mass index (BMI). The aim was to examine knee medial and lateral contact forces in gait and cycling training. Gait at self-selected …

Triangular Cosserat Point Element Method For Reducing Soft Tissue Artifact: Validation And Application To Gait, Jake Edward Deschamps, Stephen Klisch

Master's Theses

Human motion capture technology is a powerful tool for advancing the understanding of human motion biomechanics (Andriacchi and Alexander, 2000). This is most readily accomplished by applying retroreflective markers to a participant’s skin and tracking the position of the markers during motion. Skin and adipose tissue move independently of the underlying bone during motion creating error known as soft tissue artifact (STA), the primary source of error in human motion capture (Leardini et al., 2005).

(Solav et al., 2014) proposed and (Solav et al., 2015) expanded the triangular Cosserat point element (TCPE) method to reduce the effect of STA on …

Developing A Light Curve Simulation Tool For Ground And Space-Based Observations Of Spacecraft And Debris, Andrew T. Ochoa

Master's Theses

A light curve is a plot of brightness versus time of an object. Light curves are dependent on orbit, attitude, surface area, size, and shape of the observed object. Using light curve data, several analysis methods have been developed to derive these parameters. These parameters can be used for tracking orbital debris, monitoring satellite health, and determining the mission of an unknown spacecraft.

This paper discusses the development, verification, and utilization of a tool that simulates light curve data. This tool models ground-based observations, space-based observations, self-shadowing geometry, tumbling debris, and controlled spacecraft. The main output from the tool is …

An Analysis Of Camera Configurations And Depth Estimation Algorithms For Triple-Camera Computer Vision Systems, Jared Peter-Contesse

Master's Theses

The ability to accurately map and localize relevant objects surrounding a vehicle is an important task for autonomous vehicle systems. Currently, many of the environmental mapping approaches rely on the expensive LiDAR sensor. Researchers have been attempting to transition to cheaper sensors like the camera, but so far, the mapping accuracy of single-camera and dual-camera systems has not matched the accuracy of LiDAR systems. This thesis examines depth estimation algorithms and camera configurations of a triple-camera system to determine if sensor data from an additional perspective will improve the accuracy of camera-based systems. Using a synthetic dataset, the performance of …

Printed Circuit Board Design And Layout For Hobbyists, Engineers, And Students, Michael A. Derrenbacher

Master's Theses

Printed Circuit Boards (PCBs) are a ubiquitous element of virtually every electronic system manufactured world-wide. It is not a stretch of the imagination to say that if it’s electronic, there is a PCB in it. PCBs are necessary tools for electronics work, and tools need to have instructions. For better or worse, PCB knowledge is a deep and wide ocean. There is much to cover for even a surface level understanding, and there are deep areas rich in technical expertise. Navigating the ocean of knowledge is treacherous; common knowledge of yore can be downright dubious now. PCB manufacturing and electronics …

Classifying Electrocardiogram With Machine Learning Techniques, Hillal Jarrar

Master's Theses

Classifying the electrocardiogram is of clinical importance because classification can be used to diagnose patients with cardiac arrhythmias. Many industries utilize machine learning techniques that consist of feature extraction methods followed by Naive- Bayesian classification in order to detect faults within machinery. Machine learning techniques that analyze vibrational machine data in a mechanical application may be used to analyze electrical data in a physiological application. Three of the most common feature extraction methods used to prepare machine vibration data for Naive-Bayesian classification are the Fourier transform, the Hilbert transform, and the Wavelet Packet transform. Each machine learning technique consists of …

Optimizing A Virtual Human Platform For Depression/Suicide Ideation Identification For The American Soldier, Christina M. Monahan

Master's Theses

Suicide surpassed homicide to be the second leading cause of death among people 10-24 years old in the United States \cite{1}. This statistic is alarming especially when combined with the more than eight distinctly different types of clinical depression among society today \cite{2}. To further complicate this health crisis, let’s consider the current worldwide isolating pandemic often referred to as COVID-19 that has spanned 12 months. It is more important than ever to consider how we can get ahead of the crisis by identifying the symptoms as they set in and more importantly ahead of the decision to commit suicide. …

Benchmark Testing Of Gold Ribbon Bonds On Thin-Film Microchips With New Gold Ribbon Auto-Bonder, Austin Conrad

Master's Theses

The focus of this document is on the gold ribbon bond testing and creation of a bonding map for the new gold ribbon Auto-Bonder at Keysight Technologies in Santa Rosa, California. The new Auto-Bonder replaces a nearly 50-year-old machine that no longer had any documentation for the original process of thin-film microchip ribbon bonding. The original process was developed in the early 1970s to provide an electrical connection from the top to the bottom of the microchip. The electrical connection takes the place of what would be a via in a modern silicon microchip. Gold wire bonding is a common …

Wi-Fi Sensing: Device-Free In-Zone Object Movement Detection, Nicholas P. Schnorr

Master's Theses

Wi-Fi Sensing is becoming a prominent field with a wide range of potential applications. Using existing hardware on a wireless network such as access points, cell phones, and smart home devices, important information can be inferred about the current physical environment. Through the analysis of Channel State Information collected in the Neighborhood Discovery Protocol process, the wireless network can detect disturbances in Wi-Fi signals when the physical environment changes. This results in a system that can sense motion within the Wi-Fi network, allowing for movement detection without any wearable devices.

The goal of this thesis is to answer whether Wi-Fi …

On The Mobility Of Small Aperture Telescopes For Initial Orbit Determination And Apparent Magnitude Derivation Of Low Earth Satellites, Jonathan Ian Hernandez

Master's Theses

Maintaining Space Domain Awareness (SDA) of satellites in low Earth orbit (LEO) requires effective methods of tracking and characterization. Optical measurements of these objects are generally sparse due to limited access intervals and high angular rates. Light pollution and geographic obstructions may also preclude consistent observations. However, a mobile small aperture telescope grants the ability to minimize such environmental effects, thereby increasing capture likelihoods for objects within this regime. By enhancing LEO satellite visibility in this way, extensive orbital and visual data are obtainable.

An 8-inch Meade LX200GPS telescope equipped with a Lumenera SKYnyx2-0M CCD camera comprises the system that …

Characterizing Direction Specific Ganglion Cell Receptor Activation Using A Perturbation Based Decomposition Method, Camila Paola Monchini Moline

Master's Theses

Characterizing postsynaptic current signals in the retina by neuroreceptor activation frequency is important for studying the mechanism of action behind phototransduction of varied visual stimuli. A better understanding could in turn lead to the creation of methods for early detection and prevention of debilitating optical neuropathies, such as glaucoma, age-related macular degeneration, and retinitis pigmentosa. More recent in-vitro and in-vivo studies have aimed to differentiate the effects of various neurotransmitters, such as acetylcholine, GABA, and glutamate, on receiving and processing different types of visual stimuli from the retina into the visual cortex.

The focus of this work will be to …

Assessing The Effects Of Oxaliplatin On An In Vitro Three-Dimensional Human Colorectal Cancer Model, Sabrina Nelson

Master's Theses

Colorectal cancer is the third most common cancer in the United States with a 5-year late-stage survival rate of only 14%. Due to the lack of translation between animal models and clinical trials as well as the inefficacy of many chemotherapeutics in initial clinical trials, researchers are turning to in vitro drug screening models in an effort to mimic the conditions in vivo. This research project aimed to validate an in vitro tumor culture model within a microfluidic device using a clinically relevant chemotherapy drug. The first experiment consisted of a cell density and drug concentration study to determine …

Indoor Positioning Using Synchronized Ultrasonic Ofdma Signals, Julian Bartolone

Master's Theses

This paper proposes a method of short-range indoor localization using differential phase measurements of synchronized two-tone ultrasonic signals in an Orthogonal Frequency Multiple Access (OFDMA) scheme. This indoor positioning system (IPS) operates at an ultrasonic frequency of approximately 40kHz and synchronizes using an infrared signal. The OFDMA scheme allows for a receiver to process the signals from multiple transmitters continuously without the signals interfering with each other. The phases of the signals are measured using Goertzel Filters, allowing for low-complexity frequency content analysis. A MATLAB simulation using the proposed localization method is performed using four transmitter nodes in the corners …

Performance Loss Rate And Temperature Modeling In Predictive Energy Yield Programs For Utility-Scale Solar Power Plants, Katelynn M. Dinius

Master's Theses

The Gold Tree Solar Farm, designed by REC Solar, has a rated output power of 4.5 MW and began operation in 2018 to provide electricity to Cal Poly’s campus. Gold Tree Solar Farm site terrain consists of rolling hills and uneven slopes. The uneven typography results in interrow shading, requiring a modified tracking control algorithm to maximize power production. Predicting a utility solar field’s lifetime energy yield is a critical step in assessing project feasibility and calculating project revenue. The MATLAB-based predictive power model developed for this field overpredicted power in the middle of the day. The purpose of this …

Chitosan Graphene Composite Fabrication And Characterization For Treatment Of Harmful Algal Blooms And Toxins, Sarah Zetterholm

Master's Theses

Chitosan graphene composites were fabricated and characterized as a management strategy for harmful algal blooms (HABs) caused by various species of cyanobacteria. These chitosan graphene materials were compared to previously studied chitosan graphene-oxide composites in both material properties and HAB treatment. In previous studies, adsorption of the cyanobacteria onto the surface of the composite materials has been observed. Investigations of the pure materials for these composites are also included in this study to determine whether removal is a result of charge interactions with the composite, or as an inherent property of the graphene or graphene oxide. Initial results suggest that …

Optimization Of Interplanetary Transfer Trajectories Using The Invariant Manifolds Of Halo Orbits, Ryan Yedinak

Master's Theses

Traditionally, two-body dynamics have been used to design orbital trajectories for interplanetary missions using a series of Lambert’s transfers and gravity assists. Although these are reliable methods, they have extremely high fuel requirements, especially for missions to outer planets. From an orbital mechanics perspective, three ways of reducing fuel requirements for these types of missions are utilizing low energy transfer trajectories, applying low thrust engine parameters, and implementing orbit optimization techniques.

The goal of this thesis is to combine low energy transfers created from the dynamics of the Circular Restricted Three-Body Problem (CRTBP) with low-thrust orbit optimization techniques to develop …

Thermal Vacuum Chamber Modification, Testing, And Analysis, Jared C. Lehmann

Master's Theses

This work discusses the modification and analysis of the Blue Thermal Vacuum Chamber (TVAC) located at the Space Environments Lab at California Polytechnic State University, San Luis Obispo. The modified design has a cylindrical test section and can accommodate 6U Cubesats or larger for educational or research purposes. The sizing process for the modified shroud cooling system and modular heating plates is discussed. The modified cooling system uses existing nitrogen plumbing into the chamber and control systems with a new copper shroud. The modified heating system uses modular heater plates, which utilize the existing three heater strips. The modified system …

Testing And Characterization Of Polymer Laminates For Swelling, Absorption, And Cracking, Matthew W. Carlson

Master's Theses

A polymer laminate consisting of multiple layers of proprietary blends of Ethylene Vinyl Alcohol (EVOH) and Thermoplastic Polyurethane (TPU) and used in the construction of air bladders was evaluated for hygroscopic effects driving delamination and multiple layer fragmentation. These air bladders are observed to suffer delamination during a manufacturing process that involves immersion in an alcohol/water solution. A plausible underlying mechanism is differential swelling and absorption by the laminate constituents. Both room and elevated temperature swelling tests were carried out to find the absorption and swelling coefficients of the constituents. These coefficients served as input into a Finite Element Analysis …

An Examination Of The Fuzzy Inference System On Probabilistic Roadmap Path Planning, Brandon Replogle

Master's Theses

In recent years, multi-robot systems have been widely used in many applications such as warehouse inventory tracking and automatic search and rescue operations. Probability roadmap (PRM) is a typical path planning algorithm that can determine an optimal trajectory once the robot start and goal positions are specified. However, when the number of robots in the system increases, it converges slowly and may even fail to find the solution.

In this thesis, a fuzzy inference system is proposed and combined with the probability roadmap algorithm for robot path planning. Computer simulation results in five different environments show this approach is very …