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Pathfinding Interplanetary Bus Capability For The Cal Poly Cubesat Laboratory Through The Development Of A Phobos-Deimos Mission Concept, Alyssa M. Ralph

Master's Theses

With the rise of CubeSats and the demonstration of their many space applications, there is interest in interplanetary CubeSats to act for example as scientific investigations or communications relays. In line with the increasing demand for this class of small satellites, the Cal Poly CubeSat Lab (CPCL) seeks to develop a bus that could support an interplanetary science payload. To facilitate this, a mission concept to conduct science of the moons of Mars, Phobos and Deimos, is investigated by determining the mission needs for a CubeSat in a Phobos-Deimos cycler orbit through the development of a baseline design to meet …

Boost Converter Inductor Sizing Effects On The Performance Of Mppt Algorithms, Alan Nonaka

Master's Theses

With solar power and other renewables set to take over the market in the coming decades, maximum power point tracking will be essential to optimizing power output. One underserved topic of research is the effect of inductor current ripple on performance of Maximum Power Point Tracking (MPPT) algorithms. Many new topologies are focused on decreasing the ripple from PV source to increase efficiency and power output. However, not much has been done to show ripple degrading performance of MPPT algorithms. This study uses a boost converter topology to test the performance of constant duty cycle step Perturb and Observe (PO), …

Low-Cost Reaction Wheel Design For Cubesat Applications, Nicholas J. Bonafede Jr.

Master's Theses

As science instruments on CubeSats become more sensitive to the attitude of the spacecraft, better methods must be employed to provide the accuracy needed to complete the planned mission. While systems that provide the accuracy required are available commercially, these solutions are not cost-effective, do not allow the design to be tailored to a specific mission, and most importantly, do not give students hand-on experience with attitude control actuators. This thesis documents the design, modeling, and simulation of a low-cost, student-fabricated, reaction wheel system for use in 3U CubeSat satellites. The entire design process for the development of this reaction …

Traffic Privacy Study On Internet Of Things – Smart Home Applications, Ayan Patel

Master's Theses

Internet of Things (IoT) devices have been widely adopted in many different applications in recent years, such as smart home applications. An adversary can capture the network traffic of IoT devices and analyze it to reveal user activities even if the traffic is encrypted. Therefore, traffic privacy is a major concern, especially in smart home applications. Traffic shaping can be used to obfuscate the traffic so that no meaningful predictions can be drawn through traffic analysis. Current traffic shaping methods have many tunable variables that are difficult to optimize to balance bandwidth overheads and latencies. In this thesis, we study …

Non-Religious Employee's Perceptions Of Microaggressions And Their Relationship With Job Satisfaction As Moderated By Calling, Jessica Schultz

Master's Theses

The purpose of this study was to investigate the relationships between microaggressions, person-organization fit (P-O fit), job satisfaction, and calling in non-religious individuals. Established research demonstrates that job satisfaction is predicted by P-O fit (Dawis, 2005). Research with minority groups has found that microaggressions are negatively related to P-O fit and job satisfaction (Lyons, Velez, Mehta, & Neil, 2014). However, research has yet to examine these interactions with a non-religious population. Previous investigations have found that calling is positively correlated with both P-O fit and job satisfaction (Duffy & Dik, 2013; Duffy, Allan, & Dik, 2011; Hirschi, 2012), suggesting the …

Finding Identity Through Survival: The Impact Of The Hurricanes In Zora Neale Hurston’S Their Eyes Were Watching God And Jesmyn Ward’S Salvage The Bones, Crystal F. Giles

Master's Theses

This paper attempts to convey the importance of the hurricane symbol in Zora Neale Hurston’s Their Eyes Were Watching God and Jesmyn Ward’s Salvage the Bones. In both novels, the authors use the imagery of setting combined with the characterization of poor women of color in order to emphasize both the effects of environmental disaster on vulnerable communities and also the inherent power of their protagonists to overcome systemic racism combined with natural disaster. The climax of Zora Neale Hurston’s novel revolves around the deadly 1928 Okeechobee Hurricane in Florida, and the rising action of Jesmyn Ward’s novel peaks …

Interrelationships Among Monorchiid Trematodes With Special Emphasis On Some Northwestern Atlantic Genera, Apryle Panyi

Master's Theses

The Monorchiidae Odhner, 1911 is a cosmopolitan family of flukes (Trematoda: Digenea) comprising species that parasitize the digestive tract of estuarine and marine fishes as adults. Compared with other oceans, recent morphological or molecular taxonomic work conducted on monorchiid species from the northwestern Atlantic Ocean has been sparse (Manter, 1931; Overstreet, 1969; Andres et al., 2018; Wee et al., 2018, 2019, 2020). Therefore, the present work investigated the interrelationships of some monorchiids from the northwestern Atlantic Ocean with emphasis on several genera and investigated if Lasiotocus minutus (Manter, 1931) Thomas, 1959 constitutes a complex of cryptic species. New morphological and …

Effect Of Unilateral Lower-Limb Amputation On Intact Limb Biomechanics: A Systematic Review, Amanda Boyd

Master's Theses

The United States will perform 30,000-40,000 amputations this year (Ertl et al., 2019). As a common medical intervention, there is extensive research regarding rehabilitation strategies and post-operative care. Many studies have explored the effects of the affected limb and prosthetic intervention yet have neglected that of the contralateral limb (De Asha et al., 2014; Jones et al., 2006; Winter & Sienko, 1988). Studies have reported an increase in secondary musculoskeletal conditions among unilateral lower-limb amputees, particularly in the intact limb, indicating the need for additional research (Gailey et al., 2008). The purpose of this systematic review was to investigate the …

An Adaptive Approach To Gibbs’ Phenomenon, Jannatul Ferdous Chhoa

Master's Theses

Gibbs’ Phenomenon, an unusual behavior of functions with sharp jumps, is encountered while applying the Fourier Transform on them. The resulting reconstructions have high frequency oscillations near the jumps making the reconstructions far from being accurate. To get rid of the unwanted oscillations, we used the Lanczos sigma factor to adjust the Fourier series and we came across three cases. Out of the three, two of them failed to give us the right reconstructions because either it was removing the oscillations partially but not entirely or it was completely removing them but smoothing out the jumps a little too much. …

The Effect Of Constant Relative Growth Rate Versus Constant Specific Growth Rate On Oocystis Sp, Rachel Kriner

Master's Theses

In this study, a strain of Oocystis sp. (S002) was grown using two different growth strategies at three different temperatures (15°C, 20°C, 25°C). One strategy (GS1) kept a constant specific growth rate (µ) and the other (GS2) kept a constant relative growth rate (µ/µ_max). In both strategies, the cultures were grown following the protocols of a hybrid growth system. The Dilution Phase is an initial semi-continuous growth phase that involves daily dilutions until set growth criteria are met. Followed by a batch culture growth protocol where the cultures were diluted at the onset of the first day and …

Containing The Blemmye: Anxiety Towards Congenital Difference In The Old English Wonders Of The East, Jessica L. Carrell

Master's Theses

This thesis aims to illuminate early medieval anxieties about sex, procreation, and congenital physical difference by applying a lens of critical disability theory to the Old English Wonders of the East, primarily as it survives in the eleventh-century manuscript, London, British Library, Cotton MS Tiberius B.v. This thesis focuses on the textual and illustrative representation of one Wonder, the Blemmye—an approximately eight-foot-tall, eight-foot-wide androgynous humanoid, whose eyes and mouth are in their chest and who does not possess a head—as a historic embodiment of what disability meant in relation to the early medieval English worldview. This thesis considers the …

Marketing To The New Generations Of Lgbtq+ Tourists, George Smith

Master's Theses

As social acceptance for LGBTQ+ people grows, it is essential to research and understand more about tourism and its important role in the lives of LGBTQ+ populations. There are tourism communities around the country that may not be familiar with this market segment and are not sure where to start. This can leave the LGBTQ+ market segment under-represented in the tourism industry. This research sets out to answer the question, “Can tourism communities who wish to expand to newer generations of LGBTQ+ travelers market to them successfully?” Mixed research methods include an exploration of city tourism websites, interviews with tourism …

Freshwater Endmembers Impacting Carbonate Chemistry In The Mississippi Sound, Allison Savoie

Master's Theses

Coastal ecosystems are highly dynamic areas for carbon cycling and are likely to be negatively impacted by increasing ocean acidification. This research focused on dissolved inorganic carbon (DIC) and total alkalinity (TA) in the Mississippi Sound in order to understand the influence of local rivers that supply alkalinity to the area and buffer against ocean acidification. This area receives large fluxes of freshwater from local rivers, in addition to episodic inputs from the Mississippi River through a human-built diversion, the Bonnet Carré Spillway. Sites in the Mississippi Sound were sampled monthly during August 2018 to November 2019 and at weekly …

Fast Asymptotic Algorithm For Real-Time Analysis Of Multivariate Systems And Signals By Directed Transfer Function And Partial Directed Coherence Measures Of Connectivity, Farnaz Rezaei

Master's Theses

Connectivity Granger-causality measures in the frequency domain, such as the Directed Transfer Function (DTF) and Partial Directed Coherence (PDC) and their variants, constitute a family 𝜙 of measures that stem from the modeling of multidimensional time series by multivariate autoregressive (MVAR) models. 𝜙 measures have become popular for evaluation of causal interactions in neuronal networks. Surrogate and asymptotic statistical analysis are the two most frequently used methods to quantify the statistical significance of the derived interactions, a critical step for validation of the results. Each method has its own pros and cons, with the recently published asymptotic methodology being faster. …

Secondary Uses Of Ballutes After Aerocapture, Josiah Shelton

Master's Theses

Aerocapture is a method for spacecraft orbital insertion that is currently being assessed for use in interplanetary missions. This method would use a low periapsis hyperbolic entry orbit to induce drag allowing the spacecraft to slow down without the use of a propulsion system. This is accomplished by using a ballute (balloon parachute), which is released after the appropriate change in velocity necessary to achieve the desired planetary orbit. Once released, the ballute could deploy a secondary mission vehicle. A MATLAB simulation was run to understand the environment a secondary payload would undergo, such as heating and deceleration, as well …

An Application Of The Unscented Kalman Filter For Spacecraft Attitude Estimation On Real And Simulated Light Curve Data, Kent A. Rush

Master's Theses

In the past, analyses of lightcurve data have been applied to asteroids in order to determine their axis of rotation, rotation rate and other parameters. In recent decades, these analyses have begun to be applied in the domain of Earth orbiting spacecraft. Due to the complex geometry of spacecraft and the wide variety of parameters that can influence the way in which they reflect light, these analyses require more complex assumptions and a greater knowledge about the object being studied. Previous investigations have shown success in extracting attitude parameters from unresolved spacecraft using simulated data. This paper presents a focused …

Limitations Of Initial Orbit Determination Methods For Low Earth Orbit Cubesats With Short Arc Orbital Passes, James P. Johnson

Master's Theses

This thesis will focus on the performance of angles only initial orbit determi- nation (IOD) methods on observational data of low Earth orbit (LEO) CubeSats. Using data obtained by Lockheed Martin’s Space Object Tracking (SpOT) facil- ity, four methods: Gauss, Double-R, Gooding and Assumed Circular, will use different amounts of orbital arc to determine which methods perform the best in the short arc regime of less than 10 degrees of orbital arc. Once the best method for estimating the orbit is determined, there will be analysis on whether these IOD methods are accurate enough to predict a secondary observation session. …

Development And Optimization Of Imaging And Image Quantification Techniques For Tissue-Engineered Blood Vessel Mimics, Ashley Turcott

Master's Theses

Blood vessels mimics (BVMs) are tissue-engineered blood vessels used to test vascular devices in an environment that mimics some simple anatomical factors of native blood vessels. It is important to accurately and consistently assess tissue-engineered blood vessels, although there is currently a lack of standardization in Cal Poly’s Tissue Engineering Lab and in the entirety of the field. The goal of this thesis was to develop and optimize imaging and image quantification techniques for tissue-engineered blood vessels.

The first aim of this thesis optimized and compared imaging and assessment techniques for electrospun scaffolds. Images from different SEMs were compared to …

Identification Of Users Via Ssh Timing Attack, Thomas J. Flucke

Master's Theses

Secure Shell, a tool to securely access and run programs on a remote machine, is an important tool for both system administrators and developers alike. The technology landscape is becoming increasingly distributed and reliant on tools such as Secure Shell to protect information as a user works on a system remotely. While Secure Shell accounts for the abuses the security of older tools such as telnet overlook, it still has fundamental vulnerabilities which leak information about both the user and their activities through timing attacks. The OpenSSH client, the implementation included in all Linux, Mac, and Windows computers, sends each …

Combining Machine Learning And Empirical Engineering Methods Towards Improving Oil Production Forecasting, Andrew J. Allen

Master's Theses

Current methods of production forecasting such as decline curve analysis (DCA) or numerical simulation require years of historical production data, and their accuracy is limited by the choice of model parameters. Unconventional resources have proven challenging to apply traditional methods of production forecasting because they lack long production histories and have extremely variable model parameters. This research proposes a data-driven alternative to reservoir simulation and production forecasting techniques. We create a proxy-well model for predicting cumulative oil production by selecting statistically significant well completion parameters and reservoir information as independent predictor variables in regression-based models. Then, principal component analysis (PCA) …

Bayesian Test Design For Fault Detection And Isolation In Systems With Uncertainty, Evangelos Stefanidis

Master's Theses

Methods for Fault Detection and Isolation (FDI) in systems with uncertainty have been studied extensively due to the increasing value and complexity of the maintenance and operation of modern Cyber-Physical Systems (CPS). CPS are characterized by nonlinearity, environmental and system uncertainty, fault complexity and highly non-linear fault propagation, which require advanced fault detection and isolation algorithms. Therefore, modern efforts develop active FDI (methods that require system reconfiguration) based on information theory to design tests rich in information for fault assessment. Information-based criteria for test design are often deployed as a Frequentist Optimal Experimental Design (FOED) problem, which utilizes the information …

Experimental Methods For Studying Mixing And Heat Transfer Characteristics Of Effusion Jets In A Vitiated Crossflow, Benjamin Poettgen

Master's Theses

An experimental methodology for studying the mixing and heat transfer characteristics of effusion cooling jets was developed alongside an experimental test section. Preliminary investigations into these phenomena were performed in an environment relevant to gas turbine combustors. An array of effusion jets were injected into a hot vitiated crossflow containing combustion products at an average temperature of 1500K. Planar images of gas temperature via Rayleigh scattering were obtained parallel to the injection plane at various heights for two density ratios (4.65 and 3.05) and three blowing ratios (5, 7, and 10).

The main goal of this data collection was for …

Data Acquisition, Analysis, And Modeling Of Rotordynamic Systems, Michael P. Mullen

Master's Theses

Data acquisition systems for rotordynamic analysis and machine vibration were explored for the purpose of replacing the obsolete Bently Nevada ADRE 208 and ADRE for Windows system. These included the development of Matlab based custom data acquisition systems and a user interface. A model of an anisotropic rotor response undergoing transient speed was developed for the rapid prototyping and testing of data acquisition systems. Several methods for the measurement of amplitudes and phase in both the time domain and frequency domain were developed and compared. An alternate data acquisition method which is more inline with industry practices was created for …

Dynamic Analysis And Seismic Retrofit Of The Point Sur Lighthouse, Nicholas M. Dekker

Master's Theses

The Point Sur Lighthouse is an unreinforced stone masonry building completed in 1889 on the central coast of California. The lighthouse is listed on the National Register of Historic Places and is still an active aid to navigation. The original first-order Fresnel lens was removed from the lantern room and placed in safekeeping due to its high risk of damage in the event of a strong earthquake. The lens has been approved to return to its original setting but the seismic performance of the building must first be assessed in order to ensure the safety of the lens and lighthouse, …

Efficacy Of Catalytic Ozonation Advanced Oxidation Processes Compared To Traditional Ozone-Based Advanced Oxidation Processes For Degradation Of Recalcitrant Compounds, Cindy Jocelyn Sevilla Esparza

Master's Theses

This study reviews catalytic ozonation AOPs and traditional ozone-based AOPs to compare their efficiency for degradation of ozone-recalcitrant compounds. With the world’s population increasing and water becoming a scarce resource, it is important to improve current water recycling methods. Recycling water will play a large role in accommodating the increasing demand, but it will also be necessary to be improve the level of treatment in order to account for emerging contaminants (ECs) such as pharmaceuticals and personal care products. Advanced oxidation processes (AOPs) have been developed to degrade ECs that are not effectively removed by conventional wastewater treatment. The goal …

Wearable Heart Sound And Ekg Recorder, Grace R. Larson

Master's Theses

Acute congestive heart failure is a leading cause of morbidity and mortality. Patients often undergo repeated hospitalizations with an annual cost in excess of $32B dollars. Early detection of impending acute congestion allows for pharmaceutical interdiction that prevents hospitalization, improves outcomes, and reduces healthcare spending. A subcutaneous implantable monitoring device that detects impending acute congestive heart failure by using heart sounds may provide a valuable tool that can be used to titrate heart failure medications to prevent acute heart failure requiring hospitalization. The device may be used to measure changes in the intervals between the R-wave and S1 and S2 …

Design Of A Martian Communication Constellation Of Cubesats, Scott J. Pirkle

Master's Theses

Spacecraft operating on the Martian surface have used relay satellites as a means of improving communication capabilities, mainly in terms of bandwidth and availability. However, the spacecraft used to achieve this have been large spacecraft (1000s of kilograms) and were not designed with relay capability as the design priority. This thesis explores the possibility of using a CubeSat-based constellation as a communications network for spacecraft operating on the Martian surface. Brute-force techniques are employed to explore the design space of possible constellations. An analysis of constellation configurations that provide complete, continuous coverage of the Martian surface is presented. The stability …

Development And Characterization Of An Iot Network For Agricultural Imaging Applications, Jacob D. Wahl

Master's Theses

Smart agriculture is an increasingly popular field in which the technology of wireless sensor networks (WSN) has played a large role. Significant research has been done at Cal Poly and elsewhere to develop a computer vision (CV) and machine learning (ML) pipeline to monitor crops and accurately predict crop yield numbers. By autonomously providing farmers with this data, both time and money are saved. During the past development of a prediction pipeline, the primary focuses were CV and ML processing while a lack of attention was given to the collection of quality image data. This lack of focus in previous …

Distance Estimation Using Ofdm Signals For Ultrasonic Positioning, Kyman Huang

Master's Theses

This paper describes a method of estimating distance via Time-of-Flight (TOF) measurement using ultrasonic Orthogonal Frequency Division Multiplexing (OFDM) signals. Using OFDM signals allows the signals and their sub-carriers to remain orthogonal to each other while continuously transmitting. This estimation method is based on the change of phase of a traveling wave as it propagates through a medium (air for ultrasonic signals). By using signals containing multiple tones, the phase change between each frequency component is slightly different. This phase difference is dependent on the distance traveled and can thus be used to estimate distance. This paper studies the impact …

Design, Validation, And Verification Of The Cal Poly Educational Cubesat Kit Structure, Nicholas B. Snyder

Master's Theses

In this thesis, the development of a structure for use in an educational CubeSat kit is explored. The potential uses of this kit include augmenting existing curricula with aspects of hands on learning, developing new ways of training students on proper space systems engineering practices, and overall contributing to academic capacity building at Cal Poly and its collaborators. The design improves on existing CubeSat kit structures by increasing accessibility to internal components by implementing a modular backplane system, as well as adding the ability to be environmentally tested. Manufacturing of the structure is completed with both additive (Fused Deposition Modeling …