Digital Commons Network^™

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. …

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) …

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 …

Feeling Out Your Food: A Histological Analysis Of The Whisker System In Seals, Cameron Cooper

Master's Theses

The vibrissal (whisker) system is present in nearly all mammals and is especially important in deep-diving mammals. Pinnipeds (seals, sea lions, and walruses) have highly sensitive whiskers that are used to follow hydrodynamic trails created by their swimming prey. Each pinniped vibrissa is surrounded by a tripartite blood sinus system composed of an upper cavernous sinus (UCS), a ring sinus (RS), and a lower cavernous sinus (LCS). The UCS has been hypothesized to play a thermoregulatory role, insulating temperature sensitive mechanoreceptors located within the vibrissal follicle. The aim of this study was to examine this hypothesis by measuring and comparing …

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 …

Efficacy Of 3d-Printed Guide Vs Conventional Method For Conservative Endodontic Access Preparation In Extracted Upper Molars, Manuel Sato

Master's Theses

Objective: This experimental clinical trial aims to evaluate the accuracy and efficacy of a computer designed / 3D printed endodontic guide to achieve a conservative endodontic access preparation on upper molars. As a secondary objective we will determine if the endodontic guide can assist the practitioner especially when comparing two operators with a different level of experience to achieve an endodontic cavity access in a reduced time and localizing all the canals thereby preserving more dental structure Materials and Methods: This study utilized 80 extracted maxillary molars and were divided into 2 groups of a conservative access and a CBCT …

Retrospective Evaluation Of The Survival Rate Of Buccal Mini-Implants And The Factors Associated With Their Survival, Ledjo Palo

Master's Theses

ABSTRACT

Objective: The aim of this study is to evaluate the success rate of common mini-implants used on the buccal side of both the maxilla and mandible for orthodontic purposes. All orthodontic mini-implants placed at the University of Connecticut residency from July of 2013 till April of 2020 by various residents and faculty. The location and outcome of the implant was measured as success if the implant was stable or if it failed.

Materials and Methods: Records of all mini-implants placed on the buccal aspect of both maxilla and mandible of patients receiving orthodontic treatment at the University of Connecticut …

Effects Of Various Sterilization Protocols On The Dimensional Accuracy Of 3d Printed Surgical Guides For Dental Implants, Collin Shuen

Master's Theses

No abstract provided.

Context Effects On Child Object Touch And Parent Referential Speech: Implications For Autism Spectrum Disorder, Amanda Mankovich

Master's Theses

Object play provides a critical setting for early learning (West & Iverson, 2017). Previous research has established a role for context (i.e., type of activity and parent input), in shaping child touch behaviors. Although several studies have investigated the development object play, many miss key characteristics of everyday environments. Using data from the Longitudinal Study of Early Language (Naigles & Fein, 2017), we investigated how play is affected by development, parent input, and engagement in various activities across both typically developing (TD) children and children with autism spectrum disorder (ASD). We analyzed object prompts and independently coded moments toddlers touched …

Comparing The Outcomes Of Closed Vs. Open Surgical Exposure Of Palatally Impacted Canines: A Pilot Randomized Clinical Trial, Sina Banankhah

Master's Theses

No abstract provided.

Symptoms Of Autism Spectrum Disorder And Developmental Delay In Children With Low Mental Age, Rebecca P. Thomas

Master's Theses

No abstract provided.

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 …

How To Solve The Future Of The Wine Industry: An Analysis Of The Wine Industries Packaging Options When Targeting The Millennial And Gen-Z Demographics, Spencer Held

Master's Theses

The United States wine industry is currently undergoing a consumer reset, in

which most wineries are evaluating their practices to discover how they can better

market and sell wine. According to Rob McMillan, EVP and founder of Silicon Valley

Bank’s Wine Division and the author of the State of the wine industry report, boomers

are no longer the target market for wine growth given most are retiring in the next

decade with wine consumption dwindling. In order for the wine industry to grow and

excel, the wineries must solve the problem of how to engage the likes of the young, …

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 …

An Investigation Of Stress-Related Factors And Injury Occurrence In Division Iii Ice Hockey Athletes 2020., Christian Kiesel

Master's Theses

Many variables can factor into a student athlete sustaining an injury, but one of the most interesting is stress. The Stress and Injury Model is excellent in explaining how exactly history of stressors, personality, and coping mechanisms play a pivotal role in the stress response. If these three factors cause a negative stress response, then that will lead to an athlete becoming more likely to become injured. This study used 40 ice hockey players from a Division III NCAA institution. Each participant completed the Inventory of College Students’ Recent Life Experiences (ICSRLE) and Pittsburgh Sleep Quality Index (PSQI) every month …

Smartphone-Tape Method For Calculating Body Segment Inertial Parameters For Analysis Of Pitching Arm Kinetics, Jay Sterner

Master's Theses

The objectives of this study were to (1) develop a non-invasive method (referred to as Smart Photo-Tape) to calculate participant-specific upper arm, forearm, and hand segment inertial properties (SIPs) (e.g. mass, center of mass, and radii of gyration) and (2) use those Smart Photo-Tape properties in inverse dynamics (ID) analyses to calculate injury-related pitching arm kinetics. Five 20- to 23- year-old baseball pitchers were photographed holding a baseball and analyzed using the Smart Photo-Tape method to obtain 3-D inertial properties for their upper arm, forearm, and hand. The upper arm and forearm segments were modelled as stacked elliptic cylinders and …

Towards Security And Privacy In Networked Medical Devices And Electronic Healthcare Systems, Isabel Jellen

Master's Theses

E-health is a growing eld which utilizes wireless sensor networks to enable access to effective and efficient healthcare services and provide patient monitoring to enable early detection and treatment of health conditions. Due to the proliferation of e-health systems, security and privacy have become critical issues in preventing data falsification, unauthorized access to the system, or eavesdropping on sensitive health data. Furthermore, due to the intrinsic limitations of many wireless medical devices, including low power and limited computational resources, security and device performance can be difficult to balance. Therefore, many current networked medical devices operate without basic security services such …

A Parametric Study Of Formation Flight Of A Wing Based On Prandtl's Bell-Shaped Lift Distribution, Kyle S. Lukacovic

Master's Theses

The bell-shaped lift distribution (BSLD) wing design methodology advanced by Ludwig Prandtl in 1932 was proposed as providing the minimum induced drag. This study used this method as the basis to analyze its characteristics in two wing formation flight. Of specific interest are the potential efficiency savings and the optimal positioning for formation flight. Additional comparison is made between BSLD wings and bird flight in formation.

This study utilized Computational Flow Dynamics (CFD) simulations on a geometric modeling of a BSLD wing, the Prandtl-D glider. The results were validated by modified equations published by Prandtl, by CFD modeling published by …

Design Of An Electrospray Thruster Power Processing And Digital Control Interface Unit, Douglas Howe

Master's Theses

Electrospray thrusters are low thrust, high specific impulse electric propulsion devices with applications in precision attitude control of space vehicles and efficient propulsion of small spacecraft platforms. These devices operate by electrostatically extracting particles from the surface of ionic liquid propellants and accelerating them away from the vehicle at high speed. Unlike more conventional propulsion technologies which only require electronics for control and regulation, electrospray thruster systems require extensive electronics to operate. The power processing unit (PPU) is a device used to produce the high voltage levels required to operate an electrospray thruster and to measure its operating parameters. The …

Fast Chirped Signals For A Tdma Ultrasonic Indoor Positioning System, Lauren M. Williams

Master's Theses

In this paper, a new concept for ultrasonic indoor positioning based on instantaneous frequency of ultrasonic signals is presented. Nonlinear phase characteristics of ultrasonic transducers introduce a frequency deviation in ultrasonic signals. By sweeping at very fast rates, a large spike in the deviation is introduced. The artefacts observable in instantaneous frequency estimations are highly localized and present an opportunity for accurate frequency detection. In order to be useful, the artefacts need to take place within the pulse and have sufficient magnitude for accurate processing. The system consists of a transducer transmitter and receiver pair, which have a center frequency …

Writing For Each Other: Dynamic Quest Generation Using In Session Player Behaviors In Mmorpg, Sean Christopher Mendonca

Master's Theses

Role-playing games (RPGs) rely on interesting and varied experiences to maintain player attention. These experiences are often provided through quests, which give players tasks that are used to advance stories or events unfolding in the game. Traditional quests in video games require very specific conditions to be met, and for participating members to advance them by carrying out pre-defined actions. These types of quests are generated with perfect knowledge of the game world and are able to force desired behaviors out of the relevant non-player characters (NPCs). This becomes a major issue in massive multiplayer online (MMO) when other players …

Initial Orbit Determination Error Analysis Of Low-Earth Orbit Rocket Body Debris And Feasibility Study For Debris Cataloguing From One Optical Facility, Kyle Stoker

Master's Theses

This paper is predicated on determining the effectiveness of angles-only initial orbit determination (IOD) methods when limited observational data is available for low-Earth orbit (LEO) rocket body debris. The analysis will be conducted with data obtained from Lockheed Martin Space’s Space Object Tracking (SpOT) facility, focusing on their observational data from 2018 that contains tracking of rocket body debris for less than one minute per overhead pass. After the IOD accuracies are better understood, a feasibility study will follow that investigates the possibility of cataloguing LEO orbital debris from a single optical observation facility with similar observational capabilities as that …

Design Of A Custom Wrist Brace That Can Be 3d Printed From A Three-Dimensional Scan, James D. Baldwin

Master's Theses

Current arm bracing and casting methods for distal forearm and wrist fractures can lead to varying negative medicinal affects such as tightness, skin breakdown and bacteria growth which can cause infection. This can be alleviated by a flexibly compliant and breathable design while keeping the arm and hand fixed at the wrist to promote proper wrist and forearm fracture healing. There have been attempts made to create a 3D printable brace from a three-dimensional scan but they do not account for full encapsulation of the wrist, removability without breaking the brace, nor for the brace being too tight and leading …

Analysis Of Biofilm Remediation Capacity For Octenyl Succinic Anhydride (Osa), A Bioactive Food Starch Modifier Compound, Matthew R. Borglin

Master's Theses

Matthew R. Borglin

This thesis demonstrates efficacy of Octenyl Succinic Anhydride (OSA), as a biofilm sanitizer. Biofilms allow bacteria to adhere to solid surfaces with the use of excreted polymeric compounds. For example, surfaces found in food production or processing facilities such as the interior of a raw milk holding tank, are some of the most susceptible to biofilm contamination. When present, biofilms can cause a variety of negative effects, which include; reduction of product shelf life, corrosion, and outbreaks of foodborne illnesses. The close association of biofilms with the majority of foodborne illness cases led the US Environmental Protection …

Simulating Particle Packing During Powder Spreading For Selective Laser Melted Additive Manufacturing Using The Discrete Element Method In Abaqus, Priscilla Ng

Master's Theses

Metal additive manufacturing allows for the rapid production of complex parts that are otherwise impractical using conventional subtractive manufacturing techniques. Applications for additive manufacturing span across a broad array of industries including aerospace, automotive, and medical, among many others. One metric of printing success is material properties, including part density. While there has been extensive research completed for the density of printed parts, there is little published work concerning powder packing density on the build plate associated with powder spreading.

In this thesis, a Discrete Element Method (DEM) model was created in Abaqus to simulate the spreading behavior of particles …