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Training Schedule For The 56th Maintenance Group, Samantha K. O'Rourke Mar 2024

Training Schedule For The 56th Maintenance Group, Samantha K. O'Rourke

Theses and Dissertations

The 56th Equipment Maintenance Squadron (56 EMS) provides equipment maintenance and back shop maintenance for the F-35 Joint Strike Fighter. The squadron executes thousands of sorties and flight hours annually. This operations tempo requires maintenance to prevent equipment failures, minimization of aircraft downtime, insurance of safety and compliance, and training of maintenance personnel. The squadron incorporates periodic training sessions to train maintenance personnel skills needed by airmen. This research investigates the optimization of these training sessions employing mixed integer programming (MIP). A multi-objective MIP model is developed to address the complex needs of various training activities, such as: training regiments, …


Generalized Characterization Of Biaxial Media Using Ultra-Wideband Multi-Static Focused Beam System With Polarimetric Calibration, Jeffrey P. Massman Mar 2024

Generalized Characterization Of Biaxial Media Using Ultra-Wideband Multi-Static Focused Beam System With Polarimetric Calibration, Jeffrey P. Massman

Theses and Dissertations

Novel metamaterial and metasurface realizations provide unique control of the electromagnetic wave dispersion but present many challenges for accurate constitutive parameter extraction. One measurement approach commonly employed is a freespace non-destructive focus beam system. Modern implementations are configured with multi-static dual-polarized capabilities for characterizing complex materials and offer many advantages by enabling ultra-wideband sampling, multiple measurement degrees of freedom and larger sample sizes. Practical electromagnetic material characterization of complex bianisotropic media requires the advancement of wave propagation analysis and calibration schemes. This research focuses on generalized biaxial media characterization and multi-static focused beam system metrology with polarimetric calibration schemes and …


Proving The Existence Of Equichordal Tight Fusion Frames Using The Newton–Kantorovich Theorem, Staci R. Davis Mar 2024

Proving The Existence Of Equichordal Tight Fusion Frames Using The Newton–Kantorovich Theorem, Staci R. Davis

Theses and Dissertations

An equichordal tight fusion frame (ECTFF) is an example of an optimal packing of subspaces. In particular, an ECTFF is an optimal packing of points in the Grassmannian with respect to chordal distance. Equivalently, every ECTFF is an arrangement of subspaces that meet certain criteria; tightness and equichordality. The existence of an ECTFF can be rephrased as, a certain polynomial mapping as a root. Hence, one can prove the existence of an ECTFF by applying Newton–Kantorovich theorem to this polynomial mapping, given a close enough approximation of one. Newton–Kantorovich requires checking an inequality within a neighborhood of the approximate root, …


Feasibility Of A Zero-Length Spring Gravimeter For Use In Portal Monitoring, Matthew C. Stone Mar 2024

Feasibility Of A Zero-Length Spring Gravimeter For Use In Portal Monitoring, Matthew C. Stone

Theses and Dissertations

In recent years, gravimeters have become sensitive enough to theoretically measure masses of interest at distances relevant for portal monitoring. Characterizing the re[1]sponse of the gravimeter to close range masses across a large solid angle is necessary before attempting to demonstrate a portal-monitoring-like measurement due to this mission being outside the scope of typical gravimeter operations. The characterization of the gravimeter focused on three primary topics. For the position-dependent bias, it is found that the models used overestimate the expected observed gravity when the test mass is closest to the gravimeter in four out of seventeen experiments and under[1]estimate the …


Life Cycle Analysis Of Mobile Nuclear Reactor Compared To Other Alternative Fuels In Indopacom, Maria J. Hurtado Mar 2024

Life Cycle Analysis Of Mobile Nuclear Reactor Compared To Other Alternative Fuels In Indopacom, Maria J. Hurtado

Theses and Dissertations

Energy is an item that makes the military vulnerable as it is something that they depend on the most which can have negative impacts. Mobile nuclear reactors are gaining the interest of many leaders in the military as a viable option of a potential alternative fuel source. There are many positives in utilizing mobile nuclear reactors in terms of environmental impacts and feasibility of transport. Studies have shown that mobile nuclear reactors can produce very low or negligible carbon emissions during operations. The focus of this thesis is to determine the environmental impacts of nuclear reactors, logistical requirements, and determine …


Computational Analysis Of Transverse Jet Interactions On A Cone In Mach 3.9 Crossflow, Tia Massa Mar 2024

Computational Analysis Of Transverse Jet Interactions On A Cone In Mach 3.9 Crossflow, Tia Massa

Theses and Dissertations

The objective of this investigation was to analyze jet interactions using numerical simulations, which was compared to experimental data. A sharp cone with a 7-degree half-angle was modeled, along with the wind tunnel, using a 1:1 scale. Analysis of the data found the flow characteristics of the jet, including the bow shock and recirculation regions, were captured nicely in the CFD simulations, as well as the oblique shock off the nose of the cone. CFD simulations of the cone in a freestream environment depict shock-shock interactions not captured by experimental schlieren images. This research provides a rare glimpse into CFD …


Standardization Of Risk Classifications For Unmanned Space Vehicle Missions, Collin A. Gwaltney Mar 2024

Standardization Of Risk Classifications For Unmanned Space Vehicle Missions, Collin A. Gwaltney

Theses and Dissertations

This paper seeks to model risk classification levels (A-D) for 122 Space Vehicle programs. Models include multinomial logistic regression as well as random forest, a machine learning technique based on decision trees. We use independent variables (IVs) which are theoretically correlated to risk class for the regression and one random forest model. We then include all IVs and allow the random forest technique to use those which provide the most information on risk class before paring down the number of IVs to only 7. We show that the accuracy of predictions increases from 62% to 87% by using random forest …


An Investigation Of Torso Muscle Fatigue And Its Relation To Discomfort During Vertical Vibration Exposure, Nathan H. Hodges Mar 2024

An Investigation Of Torso Muscle Fatigue And Its Relation To Discomfort During Vertical Vibration Exposure, Nathan H. Hodges

Theses and Dissertations

Military and civilian helicopter pilots often experience back pain attributed to vibration exposure during flight and sustained poor posture, known as the "helicopter hunch." This study investigated torso muscle activation using surface electromyography (EMG) to assess the relationship between discomfort and muscle fatigue. Eight subjects were exposed to different vibration frequencies over two-hour periods, with EMG data collected every five minutes. Significant differences in muscle activation were observed before and after vibration exposure, suggesting increased muscle activation during vibration compared to prolonged seating alone. Discomfort surveys indicated higher discomfort during vibration.


Human Performance Modeling Architecture With Hc-130j Mission Application, Stephanie G. Slimp Mar 2024

Human Performance Modeling Architecture With Hc-130j Mission Application, Stephanie G. Slimp

Theses and Dissertations

The DOD emphasizes digital engineering using Model-Based Systems Engineering (MBSE), where MBSE includes SysML-based models of systems. Analysis of system impacts on the human operators and their performance typically occurs through non-MBSE approaches, if at all. One current process, considered the As-Is process for this research, evaluates human performance and workload using IMPRINT, a discrete event simulation (DES) tool. IMPRINT primarily exists as a standalone tool with limited built-in functionality to integrate with an MBSE tool. Using the HC-130J and its crew during a CSAR mission as the system, this research develops a generalizable and updateable human performance modeling architecture …


Rotorcraft Assisted Aircraft Inspection System: Creation And Component Assessment, Adam J. Warren Mar 2024

Rotorcraft Assisted Aircraft Inspection System: Creation And Component Assessment, Adam J. Warren

Theses and Dissertations

Aircraft require frequent inspections to perform their missions safely. Current visual inspection methods are time-consuming and dangerous for inspection personnel, but they are necessary to spot flaws that could endanger the aircraft during flight. This research explores a set of methods for transforming a set of target inspection criteria into camera specifications that will allow a UAS aircraft inspection system to perform inspections on the top skin of an aircraft. Given the minimum distance for the UAS to fly above the aircraft, minimum flaw size to search for on the aircraft, minimum number of pixels to display that flaw size, …


Utilization Of The System Engineering Design Process To Design And Test A Low-Cost Infectious Aerosol Control Mechanism For Patient Aeromedical Evacuation, Sara Shaghaghi Mar 2024

Utilization Of The System Engineering Design Process To Design And Test A Low-Cost Infectious Aerosol Control Mechanism For Patient Aeromedical Evacuation, Sara Shaghaghi

Theses and Dissertations

The aeromedical evacuation of military patients is a critical component of care for Armed Forces members. The Air Force’s ability to transport patients relies on the technology and systems available. A vital transport responsibility is keeping the patient and medical personnel safe during transport. The historical and legacy systems provide reliable transport mechanisms for the Armed Forces’ patients infected with high-level biological agents, but drawbacks must be considered. This dissertation will discuss the development, conceptual design, and initial evaluation of a new low-cost, litter-mounted patient transport system, Biological-Mitigation in Patient Transport (B-MIPT), using the “V” model of the system engineering …


Advanced Oxidation Of Methyl Tert Butyl Ether With Ultraviolet Light Emitting Diodes, Aaron R. Neal Mar 2024

Advanced Oxidation Of Methyl Tert Butyl Ether With Ultraviolet Light Emitting Diodes, Aaron R. Neal

Theses and Dissertations

Methyl Tert-Butyl Ether (MTBE) is a volatile, soluble, organic compound introduced to gasoline within the United States as a fuel oxygenator in 1979. MTBE is a common groundwater pollutant due to its high water solubility and resistance to bio-degradation; it commonly infiltrates groundwater sources via leaking underground storage tanks or fuel spills. This research employed ultraviolet light emitting diodes (UV-LEDs) and hydrogen peroxide (H2O2) induced advanced oxidation process (AOP) to treat MTBE contaminated water at the bench scale. Using four H2O2:MTBE molar peroxide ratios (100:1, 200:1, 400:1, 500:1), MTBE degradation was induced …


Signal-To-Image Method For Counterfeit Detection In Layered Security Paradigm, Jordan Williamson Mar 2024

Signal-To-Image Method For Counterfeit Detection In Layered Security Paradigm, Jordan Williamson

Theses and Dissertations

National level attention, resources, and priority regarding critical infrastructure have increased in recent years. This has led to adversaries and defenders exchanging positions between fortification and exploitation. One area that continues to be vulnerable is supply chain attacks like counterfeit insertion. This work investigates the application of converting collected signals into images from devices that may be considered for these critical networks. There are several aspects regarding the conversion of signals into images - specifically Red, Green, Blue (RGB) images. The methodology proposed here is potentially ideal fit for an initial security layer by achieving comparable classification results as more …


Spectroscopic Characterization Of Trivalent Holmium In Liyf4 And Bay2F8 Crystals, Vivian R. Hedberg Mar 2024

Spectroscopic Characterization Of Trivalent Holmium In Liyf4 And Bay2F8 Crystals, Vivian R. Hedberg

Theses and Dissertations

Yttrium-fluoride crystals doped with trivalent holmium are promising laser gain media for mid-infrared laser systems. To accurately model laser systems, a complete optical characterization of the laser gain medium is required. The key modeling parameters were obtained by a spectroscopic investigation of Ho3+ in LiYF4 and BaY2F8 crystal hosts. Several important mid-infrared laser transitions were characterized at nominal Ho3+ ion concentrations of 10-30 at.%. Polarized emission cross-sections were determined from the fluorescence spectra using the Füchtbauer-Ladenburg method. Polarized absorption cross-sections were obtained using the Integral Reciprocity method. The upper-state lifetimes were measured at room …


Personal Dosimeter Testing For High Altitude Air Crew, Seth D. Bacon Mar 2024

Personal Dosimeter Testing For High Altitude Air Crew, Seth D. Bacon

Theses and Dissertations

In 2014 the Thermo Scientific N2 electronic personal dosimeter became the aircrews’ sole means to record ionizing radiation dose. The production of this dosimeter was discontinued in July of 2021, motivating the Air Force to seek a flight-certifiable replacement. The Thermo Scientific Trudose NG, Mirion DMC 3000, and Fuji NRF-51 electronic personal dosimeters, as well as the Landauer InLight optically stimulated luminescent dosimeter, were subjected to mixed gamma and fast neutron fields simulating a high-altitude flight environment. Dosimeters are evaluated on their consistency and accuracy in reporting dose and compared to the current N2 dosimeter’s reported dose.


Single Particle Analysis Of Operation Roller Coaster Environmental Samples, Caleb J. Sapp Mar 2024

Single Particle Analysis Of Operation Roller Coaster Environmental Samples, Caleb J. Sapp

Theses and Dissertations

The release of plutonium and other actinides into the environment following a nuclear detonation or accident, poses a health risk to biological systems. The spread, or transportation of that plutonium and its daughter products through environmental and meteorological means increases the potential affect and inherent danger within the surrounding area. In the 1960’s, a study was conducted in a joint effort by the US and Great Britain to collect information regarding the spread of plutonium released into the environment through a sub-critical detonation. Soil samples from these tests were collected by the USAF in 2015, approximately 50 years after these …


Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth Mar 2024

Assessing The Relationship Between The Quasi-Biennial Oscillation And D-Region Electron Density, Natalie R. Wirth

Theses and Dissertations

High frequency (HF) communication is a vital aspect of military communication and is highly reliant upon ionospheric conditions. The variation in electron density within the lowest echelon of the ionosphere, the D-region, can significantly impact HF signals, making communication inconsistent and unreliable for these wavelengths. Despite the D-region’s important, research in this area mainly focuses on understanding the impact of space weather anomalies on the upper ionosphere, particularly its higher layers, with relatively little exploration of the D-region. This region, situated closest to the troposphere and stratosphere, has been definitively linked to solar weather events like solar flares and geomagnetic …


Hardware-In-The-Loop Autonomous Trajectory Generations For On-Orbit Rendezvous And Proximity Operations, Connor Slattery Mar 2024

Hardware-In-The-Loop Autonomous Trajectory Generations For On-Orbit Rendezvous And Proximity Operations, Connor Slattery

Theses and Dissertations

Utilizing the C++ version of GPOPS within a robotic operating system to assess efficacy on flight-ready hardware is a vital interest of the space industry today. The findings in this paper show the ability of employing GPOPS in C++ on flight-ready hardware, leveraging optimal control as the main driver to creating a control pipleline to allow a robotic platform to generate and follow an optimized trajectory with minimal user input.


Characterization Of Additively Manufactured Ti-6al-4v Yield Behavior And The Influence Of Varied Build Layer Heights, Joseph Puglisi Mar 2024

Characterization Of Additively Manufactured Ti-6al-4v Yield Behavior And The Influence Of Varied Build Layer Heights, Joseph Puglisi

Theses and Dissertations

This study evaluates the yield behavior of additively manufactured Ti-6-4 specimens in combined loading. Specimens were probed for yield across multiple load combinations along a given yield surface, holding pin one mode while applying load increments in the other mode until yield was detected. In combined loading, the yield surfaces across varied print parameters showed statistically significant, but negligible differences. This research sought to characterize the yield behavior across print parameters with the goal of increasing manufacturability. Ultimately, the benefits of the smaller print powder did not outweigh the increased manufacturing time. Furthermore, the comparison of material behavior in subsequent …


Forecasting Stock Prices Using Arima Models And Technical Analysis, Muath I. Almaiman Mar 2024

Forecasting Stock Prices Using Arima Models And Technical Analysis, Muath I. Almaiman

Theses and Dissertations

This thesis explores the integration of Autoregressive Integrated Moving Average (ARIMA) models and technical analysis to forecast stock prices, with a focus on Coca-Cola's (KO) and Netflix’s (NFLX) stocks. It examines the effectiveness of combining ARIMA models, known for their predictive accuracy in time-series analysis, with technical indicators, particularly moving averages. The study evaluates whether this integrated approach can enhance the predictive capability of stocks prices beyond traditional methods. The predictive capability is evaluated using error metrics from the ARIMA models, as well as by assessing the return earned using simple rules based on the technical indicators. Utilizing data spanning …


Housing Preferences And Vertical Expansion Potential In Riyadh City, Nasser R. Alrashed Mar 2024

Housing Preferences And Vertical Expansion Potential In Riyadh City, Nasser R. Alrashed

Theses and Dissertations

This research investigates the demand for apartment living in Riyadh's northern area and assesses its implications for vertical urban development, aligning with Saudi Arabia's Vision 2030. Employing a quantitative methodology, a structured survey was distributed to a diverse cross-section of Riyadh's population, focusing on housing preferences and perceptions of vertical living. Key findings indicate a significant demand for apartments, primarily from young to middle-aged, smaller households in low to middle-income brackets. Notably, a substantial portion of respondents showed a preference for high-rise living, suggesting a readiness for vertical expansion to manage the city's growing population. The study concludes that Riyadh's …


End-User Device Management In The Air And Space Forces, Joshua Bonvissuto Mar 2024

End-User Device Management In The Air And Space Forces, Joshua Bonvissuto

Theses and Dissertations

When achieving technical superiority is a matter a national security, it is critical that the Department of the Air Force (DAF) employs a robust Information Technology Asset Management (ITAM) strategy that maximizes mission effectiveness. Since 2022, the Office of the Chief Information Officer (SAF/CN) has been developing a plan to transform the Air Force’s ITAM strategy, primarily intending to centralize End User Device (EUD) procurement to the DAF level. For this study, a Delphi study was conducted to gather expert opinions on key aspects of SAF/CN’s new ITAM strategy to identify strengths, weaknesses, and implementation challenges. This research provides valuable …


Evaluating Butterfly Orbits In The Earth-Moon Corridor For Ssa, Lunar Surface Surveillance, And Cislunar Disposal, Contessa G. Norris Mar 2024

Evaluating Butterfly Orbits In The Earth-Moon Corridor For Ssa, Lunar Surface Surveillance, And Cislunar Disposal, Contessa G. Norris

Theses and Dissertations

The increased space activity in the region of cislunar space has created a high demand to identify, track, and monitor Resident Space Objects (RSOs) and provide cislunar disposal routes for RSOs. This research investigates the practicality of various satellite maneuvers between orbits chosen from the butterfly and dragonfly orbit families. Several simulated trajectories are compared to show the feasibility of performing a maneuver in cislunar and lunar space between the L1 and L2 Lagrange points. Additionally, lunar surface space situational awareness (SSA) capabilities of northern and southern butterfly (BN/BS) orbits were evaluated and compared to provide the most favorable dynamic …


Computational Modeling Of Single Shear Bolted Joints In Hybrid Composite Laminates With And Without Film Adhesive, Cameron S. Mcmahan Mar 2024

Computational Modeling Of Single Shear Bolted Joints In Hybrid Composite Laminates With And Without Film Adhesive, Cameron S. Mcmahan

Theses and Dissertations

This research explores the effectiveness of predicting composite failure subject to quasi-static loading conditions using computational methods. FEA models were created using Abaqus and were employed to predict composite yield and initial failure behavior. Boundary conditions are generated to replicate the loading scenario seen in the experimental tests. Computationally predicted structural response of the composite range in accuracy from a 2% difference compared to experimental values to a maximum of 63%.


Trajectory Optimization Via Direct Collocation Methods Of Boost-Glide Vehicle With Newtonian Aerodynamic Model, Andrew Bonavita Mar 2024

Trajectory Optimization Via Direct Collocation Methods Of Boost-Glide Vehicle With Newtonian Aerodynamic Model, Andrew Bonavita

Theses and Dissertations

In this work, a Newtonian aerodynamic model was developed for an elliptic cone glide geometry at a variety of angles of attack, and a functional relationship between an input angle of attack and the vehicle lift and drag coefficients was developed. This model was used in a direct orthogonal collocation framework to simulate a series of boost-glide trajectories, with objectives of minimum distance to target, minimum time to target, and maximum velocity to target. The optimal control problem was then expanded into a reachability study, considering a wide range of additional scenarios, along with studies on the vehicle range capabilities. …


Rapid Passive Safety Determination Using Backward Reachability For Spacecraft Rendezvous And Proximity Operations, Kealy A. Murphy Mar 2024

Rapid Passive Safety Determination Using Backward Reachability For Spacecraft Rendezvous And Proximity Operations, Kealy A. Murphy

Theses and Dissertations

As the prevalence of autonomous space systems rise, there is an urgent demand for robust and precise safety analysis. The future of RPO necessitates coordination of satellites in a dynamic and congested space environment while avoiding collisions. Passive safety in RPO refers to the implementation of strategies that minimize the collision risk in the event of orbital or control deviations. This multifaceted problem includes maintaining KOZ, utilizing predictive modeling to anticipate collision scenarios, and designing spacecraft with robust GNC systems allowing for timely course corrections. The current literature’s focus has been on the separation distance between spacecraft as a primary …


Optimal Trajectory Solutions For Unmanned Pursuer/Evader Offensive Counterair Including Engagement Zone, Alexander Hansen Mar 2024

Optimal Trajectory Solutions For Unmanned Pursuer/Evader Offensive Counterair Including Engagement Zone, Alexander Hansen

Theses and Dissertations

This work considers a two-actor scenario of a faster, unmanned pursuer with an engagement zone (EZ) and a non-maneuvering mobile evader. The pursuer aims to capture an evader with a circular EZ. The EZ is dynamic and shifts as a function of the evader’s velocity vector. As the evader’s strategy changes, the EZ relative to the pursuer adjusts based on relative heading and speed of the two agents. Using nonlinear optimal control techniques, the optimal trajectory and minimum time to engage the evader are determined for various pursuer initial headings and positions through MATLAB simulation. The results build a control …


Influence Of Environmental Barrier Coatings On The Overall Effectiveness Of A Film Cooled Ceramic Matrix Composite Plate, Shane P. Lindsay Mar 2024

Influence Of Environmental Barrier Coatings On The Overall Effectiveness Of A Film Cooled Ceramic Matrix Composite Plate, Shane P. Lindsay

Theses and Dissertations

Silicon carbide ceramic matrix composites, a promising new potential upgrade over the conventional metals currently used for jet engine turbine blades, have a propensity to oxidize in a combustion environment. Engine manufacturers often apply environmental barrier coatings to prevent the composites from oxidizing. What is unclear, however, is how environmental barrier coatings effect underlying composite temperatures. This research examined the coatings’ effects by first characterizing the influence of environmental barrier coatings on the underlying temperature of a protected ceramic, then evaluating the significance of lateral conduction for cooling a coated ceramic, and finally comparing cooling results for coated and uncoated …


Positioning, Navigation, And Timing (Pnt) Study For Select Multibody Environments, Kaitlin R. Roberts Mar 2024

Positioning, Navigation, And Timing (Pnt) Study For Select Multibody Environments, Kaitlin R. Roberts

Theses and Dissertations

In the renewed 21st-century race to the Moon, the demand for heightened mission capabilities in the cislunar region, lunar surface, and beyond is imperative. With an escalating number and complexity of lunar missions, persistent positioning, navigation, and timing (PNT) capabilities are becoming paramount. This thesis presents innovative lunar PNT architectures designed to provide continuous coverage of the lunar South Pole, near-continuous coverage of the entire lunar surface, and coverage of the Earth-Moon Corridor. As space faring countries advance from lunar exploration to Mars, similar assets are essential for astronaut exploration in this extraterrestrial environment. Additionally, this thesis introduces and meticulously …


Preliminary Assessment Of Cislunar Disposal Orbits, Ryan M. Sargent Mar 2024

Preliminary Assessment Of Cislunar Disposal Orbits, Ryan M. Sargent

Theses and Dissertations

This thesis investigates the disposal of end-of-life spacecraft from key orbits with a focus on minimizing delta-v expenditure and preventing debris propagation. Simulated Lyapunov and halo orbits around the L2 Lagrange point are analyzed for disposal feasibility. Both impulsive and continuous thrust methods are explored to achieve disposal trajectories. Continuous thrust will be modeled after a Hall thruster utilizing electric propulsion. Leveraging the Circular Restricted Three Body Problem framework, low delta-v cost trajectories are computed, with a multi-level correction algorithm optimizing total delta-v via heteroclinic connections. The study assesses various delta-v amounts for Earth-Moon system escape and evaluates the potential …