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2020

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Articles 7381 - 7410 of 10642

Full-Text Articles in Engineering

Space-Based Localization Of Radio Frequency Transmitters Utilizing Macaulay Resultant And Heuristic Optimization Methods, Jessica M. Wightman Mar 2020

Space-Based Localization Of Radio Frequency Transmitters Utilizing Macaulay Resultant And Heuristic Optimization Methods, Jessica M. Wightman

Theses and Dissertations

This research focuses on radio frequency geolocation of space objects utilizing space-based platforms. Geolocation has long been the solution for locating objects. In particular, this study examines the scenario of two cooperative receivers geolocating a transmitter in close proximity. An algorithm is developed to calculate the initial estimated transmitter location and projected orbital trajectory. The algorithm uses the Macaulay method of solving a system of polynomials as well as heuristic optimization techniques to locate a transmitter with respect to receivers at different time intervals. For the scenarios investigated, both Macaulay and heuristic optimization methods achieve initial relative orbit determination.


The Effects Of Funding Gaps On Depot Maintenance Hours, Carlo S. D'Amato Mar 2020

The Effects Of Funding Gaps On Depot Maintenance Hours, Carlo S. D'Amato

Theses and Dissertations

The relationship between expenditures and readiness level is a topic of interest to military senior leaders, defense resource planners, and the American taxpayer alike. Senior leaders within the Air Force (AF) justify increased defense budgets by pointing to the potential adverse effects that decreased funding could have on military readiness. Resource planners within the AF are then tasked with the responsibility of ensuring that budgets are allocated most effectively to maximize the AF's ability to project airpower across a variety of contingency operations. This thesis investigates the relationship between budgets and readiness by examining the relationship between depot level funding …


Development Of A Drone-Mounted Wireless Attack Platform, Nathan V. Barker Mar 2020

Development Of A Drone-Mounted Wireless Attack Platform, Nathan V. Barker

Theses and Dissertations

The commercial drone market has grown rapidly due to the increasing utility and capabilities of drones. This new found popularity has made it possible for inexpensive drones capable of impressive carry capacities and flight times to reach the consumer market. These new features also offer an invaluable resource to wireless hackers. Capitalizing on their mobility, a wireless hacker can equip a drone with hacking tools to surpass physical security (e.g. fences) with relative ease and reach wireless networks. This research seeks to experimentally evaluate the ability of a drone-mounted wireless attack platform equipped with a directional antenna to conduct wireless …


Preliminary Study Of Communication Network Characterization Towards Improved Organizational Behavior, Taylor F. Flaxington Mar 2020

Preliminary Study Of Communication Network Characterization Towards Improved Organizational Behavior, Taylor F. Flaxington

Theses and Dissertations

Nearly one third of the Air Force acquisition system’s large programs are over cost and half are over budget; performance must improve. This research applies a systems perspective to this challenge and frames the acquisition system as a complex system of systems. It is a system composed of people in multiple organizations; organizations interacting with one another to develop, acquire and sustain weapon programs. The system’s performance is an emergent behavior of its components (people), structure and processes. Communication networks are a view of a system’s structure, revealing the flows and interactions between components (people) as the system accomplishes its …


A Reference Architecture For Cubesat Development, Luke J. Farrell Mar 2020

A Reference Architecture For Cubesat Development, Luke J. Farrell

Theses and Dissertations

Developing a space vehicle is a complex and detailed process, and while CubeSats are smaller and more accessible than traditional satellites the design process is relatively unchanged. Creating a viable space vehicle design requires detailed analysis of a set of mission needs in order to define the mission, with this need set used to then create the specific mission requirements. These requirements are used to formulate a concept of operations, and then move into developing a physical system for executing the mission. The successful production of CubeSats within an organization is contingent upon the accurate execution of the general CubeSat …


An Analysis Of The Viability Of 3d-Printed Construction As An Alternative To Conventional Construction Methods In The Expeditionary Environment, Jeneé A. Jagoda Mar 2020

An Analysis Of The Viability Of 3d-Printed Construction As An Alternative To Conventional Construction Methods In The Expeditionary Environment, Jeneé A. Jagoda

Theses and Dissertations

Conventional construction is believed by some to have reached its technological limit of performance, making it increasingly difficult for conventional construction methods to meet the U.S. military’s core standards of quality, cost, and timeliness in the expeditionary environment. While still in its infancy, 3D-printed construction has the potential to revolutionize the way the military performs construction in deployed environments. This research conducts a systematic review of the viability of 3D-printed construction to investigate whether or not it is now or could be a viable replacement for conventional construction methods, specifically in remote environments where conventional construction capability may be limited. …


Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite With Environmental Barrier Coating At 1200°C In Air And In Steam, Thaddeus M. Williams Mar 2020

Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite With Environmental Barrier Coating At 1200°C In Air And In Steam, Thaddeus M. Williams

Theses and Dissertations

Advanced aerospace applications such as aircraft turbine engine components, hypersonic flight vehicles, and spacecraft reentry thermal protection systems require structural materials that have superior long-term mechanical properties under high temperature, high pressure, and varying environmental factors, such as moisture. Because of their low density, high strength and fracture toughness at high temperatures SiC fiber-reinforced SiC matrix composites are being evaluated for aircraft engine hot-section components. In these applications the composites will be subjected to various types of mechanical loadings at elevated temperatures in oxidizing environments. Because their constituents are intrinsically oxidation-prone, the most significant problem hindering SiC/SiC composites is oxidation …


Evaluation Framework For Cislunar Space Domain Awareness (Sda) Systems, Simon R. Knister Mar 2020

Evaluation Framework For Cislunar Space Domain Awareness (Sda) Systems, Simon R. Knister

Theses and Dissertations

Modern space missions are increasingly transiting cislunar space, requiring expansion of existing Space Traffic Management (STM) functions. Legacy Space Domain Awareness (SDA) systems were not purpose-built to detect and track cislunar objects, which could require acquisition of a new system of systems. There are numerous parameters that could be varied for each system, as well as the type and location of systems across the architecture. This research attempts to solve this problem by applying a model-based systems engineering (MBSE) approach to assess the performance and financial burden of a given system of systems. Fitness metrics are developed based upon the …


Vote Forecasting Using Multi-Objective Decision Analysis, Connor G. Crandall Mar 2020

Vote Forecasting Using Multi-Objective Decision Analysis, Connor G. Crandall

Theses and Dissertations

In December 2018, the United States Federal Government began what would become the longest government shutdown in U.S. history. This was the 21st shutdown since the adoption of the current appropriations process and 4th of the last decade. These shutdowns occur after government departments and agencies submit budget requests to Congress and the legislature is unable to come to an agreement to pass an appropriations bill. There is no clear solution to this problem. But this study hypothesizes that government departments and agencies could benefit from considering the political viability of their own budget requests prior to submitting them to …


A Life-Cycle Analysis Of The Thermal Energy Transfer In Prototypical Air Force Office Building Construction Using Best Value Insulation Standards, Michael E. Canfield Mar 2020

A Life-Cycle Analysis Of The Thermal Energy Transfer In Prototypical Air Force Office Building Construction Using Best Value Insulation Standards, Michael E. Canfield

Theses and Dissertations

The United States Department of Defense (DoD) possesses over 560,000 buildings and structures around the world which require electricity to maintain and operate. The energy costs associated with the operations of these building is approximately $4 billion per year. Sustainable infrastructure management is a crucial opportunity to improve and establish a prudent, manageable, and successful DoD budget. This research identified, modeled, and simulated thermal energy-efficient standards in building construction in order to recognize the best value standards as opportunities for potential cost savings. EnergyPlus and OpenStudio Building Performance Simulation (BPS) software was used to model the energy flow into and …


Trade-Space Analysis Of A Small Unmanned Vehicle System For Radiological Search Missions, Sam B. Harriger Mar 2020

Trade-Space Analysis Of A Small Unmanned Vehicle System For Radiological Search Missions, Sam B. Harriger

Theses and Dissertations

Nuclear and radiological terrorism is a persistent threat to United States national security. The research and development of new technological capabilities is vital to bolstering emergency response and prevention capabilities in support of national security initiatives. This research characterized the applicable trade-space for a system of unmanned vehicles deployed for search, detection, and identification of radiological source material. Exploration included the development of a CONOPS, a functional decomposition and physical allocation, design considerations, and an analysis of feasibility and utility. The concept system comprises of a ground control station, ground vehicle, hybrid-electric multirotor, and fixed-wing vehicle with an open architecture …


Optimization Of Airfield Parking And Fuel Asset Dispersal To Maximize Survivability And Mission Capability Level, Ryley R. H. Paquette Mar 2020

Optimization Of Airfield Parking And Fuel Asset Dispersal To Maximize Survivability And Mission Capability Level, Ryley R. H. Paquette

Theses and Dissertations

While the US focus for the majority of the past two decades has been on combatting insurgency and promoting stability in Southwest Asia, strategic focus is beginning to shift toward concerns of conflict with a near-peer state. Such conflict brings with it the risk of ballistic missile attack on air bases. With 26 conflicts worldwide in the past 100 years including attacks on air bases, new doctrine and modeling capacity are needed to enable the Department of Defense to continue use of vulnerable bases during conflict involving ballistic missiles. Several models have been developed to date for Air Force strategic …


Civil Engineer Company Grade Officer Competency-Based Education Modeling, Scott R. Guerin Mar 2020

Civil Engineer Company Grade Officer Competency-Based Education Modeling, Scott R. Guerin

Theses and Dissertations

The importance of continuing education for professionals cannot be understated. This importance is doubly true for Air Force Civil Engineer Company Grade Officers who are members of not only the profession of engineering, but also the profession of arms. Air Force senior leaders understand this importance and required an update to the existing developmental education model, with a paradigm shift toward competency-based education and credentialing. Unfortunately, the Air Force Civil Engineer career field does not currently possess the required information to create a model in compliance with the senior leader directives. This research aims at establishing the required characteristics of …


Optimized Off-Grid Energy Systems Using Climate-Based Energy Demand For Soft-Walled Facilities, Jay F. Pearson Mar 2020

Optimized Off-Grid Energy Systems Using Climate-Based Energy Demand For Soft-Walled Facilities, Jay F. Pearson

Theses and Dissertations

Remote contingency military operations often require the use of temporary facilities powered by inefficient diesel generators that are expensive to operate and maintain. Site planners can reduce operating costs by augmenting generators with hybrid energy systems, but they must select the optimal design configuration based on the region’s climate to meet the power demand at the lowest cost. To assist planners, this paper proposes two innovative, climate-optimized, hybrid energy system selection models. The first model is capable of selecting the facility insulation type, solar array size, and battery backup system to minimize the annual operating cost. The Hybrid Energy Renewable …


Development, Test And Evaluation Of Autonomous Unmanned Aerial Systems In A Simulated Wide Area Search Scenario: An Implementation Of The Autonomous Systems Reference Architecture, Katherine E. Cheney, David D. King Mar 2020

Development, Test And Evaluation Of Autonomous Unmanned Aerial Systems In A Simulated Wide Area Search Scenario: An Implementation Of The Autonomous Systems Reference Architecture, Katherine E. Cheney, David D. King

Theses and Dissertations

The implementation and testing of autonomous and cooperative unmanned systems is challenging due to the inherent design complexity, infinite test spaces, and lack of autonomy specific measures. These challenges are limiting the USAF's ability to deploy and take advantage of tactical and strategic advantages offered by these systems. This research instantiates an Autonomous System Reference Architecture (ASRA) on a Wide Area Search (WAS) scenario as a test bed for rapid prototyping and evaluation of autonomous and cooperative systems. This research aims to pro- vide a framework to evaluate the system’s ability to achieve mission and autonomy objectives, develop reusable autonomous …


Investigating Lifecycle Costs Of Optimized Battery-Photovoltaic Systems On A Forward Operating Base, Neal S. Fennell Mar 2020

Investigating Lifecycle Costs Of Optimized Battery-Photovoltaic Systems On A Forward Operating Base, Neal S. Fennell

Theses and Dissertations

The purpose of this research was to investigate the total life-cycle cost of using utility-scale battery systems to increase the energy efficiency of forward operating bases, thereby reducing the burden of diesel fuel logistics. Specifically, this thesis answered three research questions addressing optimal sizing for various battery types connected with photovoltaic grids, logistical parameters directly impacting total cost, and the cost of increasing the energy resilience of the network. The research questions were answered through a review of literature, modeling, and data analysis. The model determines an optimal size and area for a Vanadium redox flow, Lithium-ion, or Lead-acid battery …


Recognizing Potential Cyberspace Warriors Through The Use Of Suspicion Propensity Index, Meghan G. Strang Mar 2020

Recognizing Potential Cyberspace Warriors Through The Use Of Suspicion Propensity Index, Meghan G. Strang

Theses and Dissertations

The Air Force currently suffers from excessively high attrition rates in the cyberspace career. The field is currently aiming to develop an entrance examination for the career, striving to improve personnel selection and decrease these high attrition rates. The attribute of suspicion is a key focus of the preliminary examination development, theorizing that it is a potential indicator present among competent cyber operators. This research makes use of the Suspicion Propensity Index (SPI), a reliable measure of one’s tendency to be suspicious, along with the highly cited Mayer’s trust questionnaire in order to compare the attributes that appear in successful …


The Impact Of Changing The Size Of Aircraft Radar Displays On Visual Search In The Cockpit, Justin R. Marsh Mar 2020

The Impact Of Changing The Size Of Aircraft Radar Displays On Visual Search In The Cockpit, Justin R. Marsh

Theses and Dissertations

Advances in sensor technology have enabled our fighter aircraft to find, fix, track, target, engage (F2T2E) at greater distances, providing the operator with more data within the battlefield. Modern aircraft are designed with larger displays while our legacy aircraft are being retrofitted with larger cockpit displays to enable display of the increased data. While this modification has been shown to enable improvements in human performance of many cockpit tasks, this effect is often not measured nor fully understood at a more generalizable level. This research outlines an approach to comparing human performance across two display sizes in future F-16 cockpits. …


Golng Off The Grid: Optimizing Solar Renewable Energy Systems At Remote Locations To Minimize Logistics Requirements, Increase Sustainability, And Strengthen Energy Assurance, Nathanael J. Thomsen Mar 2020

Golng Off The Grid: Optimizing Solar Renewable Energy Systems At Remote Locations To Minimize Logistics Requirements, Increase Sustainability, And Strengthen Energy Assurance, Nathanael J. Thomsen

Theses and Dissertations

Grid-based electrical infrastructure is unavailable at many remote locations including developing nation communities, isolated construction sites, and military contingency bases. Powering these locations with diesel generators requires regular fuel resupply, resulting in increased costs, environmental impacts, and burdensome logistics—making generators an obstacle for energy resiliency and sustainability. This research examines using solar renewable energy systems to replace generators at remote locations and presents a multi-objective optimization model that minimizes logistics variables. Replacing a single deployed generator would save over 500,000 gal of fuel annually, eliminating the need for 100 fuel tanker deliveries.


An Analysis Of Tinker Air Force Base Thermal Spray Hazardous Waste Stream From 2003-2019 And Its Potential Reclamation, Amy E. Silverbush Mar 2020

An Analysis Of Tinker Air Force Base Thermal Spray Hazardous Waste Stream From 2003-2019 And Its Potential Reclamation, Amy E. Silverbush

Theses and Dissertations

The disposal of hazardous waste threatens the environment and human health. However, certain hazardous wastes can be recycled or reclaimed to alleviate environmental and financial impacts associated with its disposal and resource demand reduction. A hazardous powder produced by the United States Air Force stems from aircraft maintenance and is composed of metals and ceramics, called thermal spray. This waste can be purchased by an industrial recycler if the waste is composed of valuable metals. Historic data from the depot-level maintenance base Tinker Air Force Base initiated an analysis of annual thermal spray hazardous waste disposal fees, which combined with …


Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal Mar 2020

Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal

Theses and Dissertations

Thermal Ionization Mass Spectrometry (TIMS) is an invaluable tool in nuclear forensics as it enables isotopic assays of actinides to be measured, permitting analysis to include special nuclear material isotopic assays, nuclear reactor monitoring, and treaty verification. In one method of measurement for the TIMS system, samples are deposited in solution form on high-purity rhenium filaments. The filaments are heated to evaporate the solvent, and then further heated to cause sample ionization, permitting the sample to be transmitted through a magnetic field which separates ions based on mass to charge ratio into detectors for counting. Heavier ions will be deflected …


The Effect Of Aeration Rate And Free-Floating Carrier Media On The Emission Of Bacillus Globigii In Bioaerosols, Andrew J. Owens Mar 2020

The Effect Of Aeration Rate And Free-Floating Carrier Media On The Emission Of Bacillus Globigii In Bioaerosols, Andrew J. Owens

Theses and Dissertations

Aerosols produced by turbulent mechanical mixing and bubble aeration at Waste Water Treatment Plants (WWTPs) become bioaerosols with the entrainment of biological materials. Bioaerosols become a public health risk when human pathogens are present. This study evaluated bioaerosols containing Bacillus globigii (BG) spores, and the effects that aeration rate and the addition of Free-Floating Carrier Media (FFCM) had on the amount of BG spores collected following aerosolization. A series of laboratory-scale experiments investigated two different sizes of floating polystyrene spheres as FFCM and four different aeration rates. When the differences in compared aeration rates were sufficiently large, a positive correlation …


Verifying And Improving A Flight Reference System's Performance, Loren E. Myers Mar 2020

Verifying And Improving A Flight Reference System's Performance, Loren E. Myers

Theses and Dissertations

The 746th Test Squadron (746 TS) at Holloman AFB, NM operates the Ultra High Accuracy Reference System (UHARS) as part of its mission positioning and navigation test. This research presents a method for verifying the performance of a flight reference system using a Delta-Position velocity derived from radio navigation positioning measurements. The algorithm presented may utilize Global Positioning System (GPS) or the Locata ground based positioning system. In the latter case, Locata provides a velocity truth independent from GPS. The accuracy of Locata and GPS are assessed and UHARS velocity measurements are characterized both in nominal and GPS denied applications.


Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments At The National Ignition Facility, Nicholas J. Quartemont, James E. Bevins, Rachel N. Slaybaugh, Lee A. Bernstein Mar 2020

Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments At The National Ignition Facility, Nicholas J. Quartemont, James E. Bevins, Rachel N. Slaybaugh, Lee A. Bernstein

Faculty Publications

An energy tuning assembly ETA was developed to spectrally shape the National Ignition Facility NIF deuterium-tritium D-T fusion neutron source to a notional thermonuclear and prompt fission neutron spectrum TNPFNS to approximate a boosted nuclear device. The spectrally shaped neutron environment can be used to create realistic synthetic post-detonation weapon debris that contain spectrally accurate fission products across all mass chains to enhance U.S. technical nuclear forensics capabilities for nuclear weapon attribution and device reconstruction. This research performed nuclear data covariance analysis through stochastic sampling techniques to predict the performance of an ETA to create the objective TNPFNS, assess anticipated …


Applications Of Unmanned Aerial Systems (Uas): A Delphi Study Projecting Future Uas Missions And Relevant Challenges, Alberto Sigala, Brent T. Langhals Mar 2020

Applications Of Unmanned Aerial Systems (Uas): A Delphi Study Projecting Future Uas Missions And Relevant Challenges, Alberto Sigala, Brent T. Langhals

Faculty Publications

Over recent decades, the world has experienced a growing demand for and reliance upon unmanned aerial systems (UAS) to perform a broad spectrum of applications to include military operations such as surveillance/reconnaissance and strike/attack. As UAS technology matures and capabilities expand, especially with respect to increased autonomy, acquisition professionals and operational decision makers must determine how best to incorporate advanced capabilities into existing and emerging mission areas. This research seeks to predict which autonomous UAS capabilities are most likely to emerge over the next 20 years as well as the key challenges for implementation for each capability. Employing the Delphi …


Optimizing The Environmental And Economic Sustainability Of Remote Community Infrastructure, Jamie E. Filer, Justin D. Delorit, Andrew J. Hoisington, Steven J. Schuldt Mar 2020

Optimizing The Environmental And Economic Sustainability Of Remote Community Infrastructure, Jamie E. Filer, Justin D. Delorit, Andrew J. Hoisington, Steven J. Schuldt

Faculty Publications

Remote communities such as rural villages, post-disaster housing camps, and military forward operating bases are often located in remote and hostile areas with limited or no access to established infrastructure grids. Operating these communities with conventional assets requires constant resupply, which yields a significant logistical burden, creates negative environmental impacts, and increases costs. For example, a 2000-member isolated village in northern Canada relying on diesel generators required 8.6 million USD of fuel per year and emitted 8500 tons of carbon dioxide. Remote community planners can mitigate these negative impacts by selecting sustainable technologies that minimize resource consumption and emissions. However, …


Comparative And Performative Investigation Of Various Data-Based And Conventional Theoretical Methods For Modelling Heat Pipe Solar Collectors, Abdellah Shafieian, Hossein Parastvand, Mehdi Khiadani Mar 2020

Comparative And Performative Investigation Of Various Data-Based And Conventional Theoretical Methods For Modelling Heat Pipe Solar Collectors, Abdellah Shafieian, Hossein Parastvand, Mehdi Khiadani

Research outputs 2014 to 2021

Solar collector, as the key component of any solar system, has always been the focal point of research in the field of solar energy. Based on the literature, data-based methods, which have been proven to be promising in accurate modelling of solar collectors, have not been used for modelling heat pipe solar collectors (HPSCs). At the same time, accurate equations relating the thermal efficiency of solar collectors to the operational and climatic conditions have not been obtained for HPSCs. Therefore, in this study, various data-based and energy balance-based modelling methods were proposed, and based on different accuracy criteria, their precisions …


Supermileage Vehicle Drivetrain Design, Griffin M. Kraemer, Kai Meter, Arya Mahdavian Mar 2020

Supermileage Vehicle Drivetrain Design, Griffin M. Kraemer, Kai Meter, Arya Mahdavian

Mechanical Engineering

The current Cal Poly Supermileage team has faced issues regarding the efficiency and durability of their SMV vehicle’s drivetrain. After conducting research to solve their current issues, we developed a final drivetrain configuration that will improve the performance and life of the vehicle. This report outlines some of the completed research including: a table of designs used by other teams, a table of patents that can be applied to our design, and a list of technical literature we can use to better our design. It also summarizes our goals and objectives, including a table of the engineering specifications of the …


Moment Redistribution In Continuous Rc Beams Top Strengthened With Steel And Cfrp Plates, Amr Ibrahim, Ayman Khalil, Shady Salem, Mahmoud El-Kateb Mar 2020

Moment Redistribution In Continuous Rc Beams Top Strengthened With Steel And Cfrp Plates, Amr Ibrahim, Ayman Khalil, Shady Salem, Mahmoud El-Kateb

Civil Engineering

It is common practice to retrofit continuous reinforced concrete (RC) beams by fiber reinforced polymer (FRP) or steel plates. This can cause a significant amount of moment redistribution (MR) which results in an efficient and economic design when taken into consideration. There is lack in research regarding MR in continuous RC beams when strengthening plates are applied only at the top side at the hogging regions. The main purpose of this paper is to assess MR in continuous RC beams top strengthened with steel and/or carbon fiber reinforced polymer (CFRP) plates. In this respect, a nonlinear finite element model was …


Left Atrial Appendage Printing Process, Areli Reyes, Brandon James Mukai, Mia Noelle Von Knorring Mar 2020

Left Atrial Appendage Printing Process, Areli Reyes, Brandon James Mukai, Mia Noelle Von Knorring

Biomedical Engineering

The left atrial appendage senior design team aims to assist in closing off the left atrial appendage that is susceptible to coagulation due to non-valvular atrial fibrillation. Coagulation in the left atrial appendage (LAA) can be life threatening as it can lead to a stroke. Dr. Chris Porterfield performs a procedure that uses the Boston Scientific Watchman to close the appendage. He finds that sizing the Watchman properly is difficult with limited visuals from live CT scans. He proposed converting the CT scans into a 3D printed model of the left atrial appendage and left atrium so he can visually …