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Articles 901 - 930 of 5699
Full-Text Articles in Engineering
Characterizing Security Monitor And Embedded System Performance Across Distinct Risc-V Ip-Cores, Justin C. Tullos
Characterizing Security Monitor And Embedded System Performance Across Distinct Risc-V Ip-Cores, Justin C. Tullos
Theses and Dissertations
Embedded systems have seen a rapid integration into all forms of industry as they continue to shrink in size and cost. The increased demand has highlighted a need for secure systems that are robust to attacks and demonstrate reliable performance, especially if the system operation is time-critical. E orts to characterize the performance of secure systems have been obstructed either by proprietary restrictions or ineffective analysis. Proprietary technology limits a comprehensive validation of a system's security and the implications it might have on performance. Performance analysis that is disclosed often lacks sufficient statistical rigor needed for a complex system. A …
Commuting Compositions For Quantum Circuit Reduction, Brenna R. Cole
Commuting Compositions For Quantum Circuit Reduction, Brenna R. Cole
Theses and Dissertations
Quantum circuit simplification improves program execution on quantum hardware by reducing error from prolonged environmental interaction and noisy gate operations. One simplification technique is template matching, which repeatedly conducts local optimization by replacing small sequences of gates within a circuit by optimized versions. Underlying this method is the problem of identifying sequences matching templates. This is challenging because some, but not all, gates can commute within a circuit. This means there may not be a subcircuit that matches a template in the original circuit specification, but a match may exist in an equivalent rearrangement of gates. In such cases, certain …
Development Of A Testbed For Foot Mounted Based Pedestrian Dead Reckoning (Pdr) Systems, Jordan E. Eldridge
Development Of A Testbed For Foot Mounted Based Pedestrian Dead Reckoning (Pdr) Systems, Jordan E. Eldridge
Theses and Dissertations
Over the last several years of research into the field of Pedestrian Dead Reckoning (PDR), there have been varying degrees of success in providing a viable individual navigation system. The PDR solutions developed utilize everything from a single Inertial Measurement Units (IMU) to several IMUs with additional sensors. One specific PDR solution identified that by utilizing a micro-mechanical Inertial Measurement Unit (IMU) on each foot (along with the application of Zero Velocity Updates (ZUPT) and foot-to-foot range measurements) a reliable method of PDR tracking could be accomplished. Their study concludes that further evaluation is required for this foot-mounted solution to …
A Cyber Threat Taxonomy And A Viability Analysis For False Injections In The Tcas, John W. Hannah
A Cyber Threat Taxonomy And A Viability Analysis For False Injections In The Tcas, John W. Hannah
Theses and Dissertations
This thesis provided background information on the Traffic Collision Avoidance System (TCAS). Additionally, the thesis developed a threat taxonomy for TCAS, resulting in the determination that a false injection attack presents the most comprehensive risk. Moreover, the thesis presents the development of a program to determine what ranges, altitudes, and relative bearings are most vulnerable to a false injection attack. The program includes test for all requirements of a successful false injection. Furthermore, the thesis presents an analysis of results and creates threat maps as situational awareness tools. Lastly, the thesis discusses potential solutions to the false injection attack, covers …
Spatially Separable Blind Deconvolution Of Long Exposure Astronomical Imagery, Justin S. Lee
Spatially Separable Blind Deconvolution Of Long Exposure Astronomical Imagery, Justin S. Lee
Theses and Dissertations
In this thesis, a spatially separable blind deconvolution algorithm is demonstrated that achieves a significantly faster processing time and superior sensitivity when processing long-exposure image data of unresolvable objects from a ground-based telescope. The proposed approach takes advantage of the structure of the long exposure point spread functions radial symmetric characteristics to approximate it as a product of one dimensional horizontal and vertical intensity distributions. Objects at geosynchronous or geostationary orbit also can be well approximated as being spatially separable as they are, in general non-resolvable. The algorithms performance is measured by computing the mean-squared error compared with the true …
An Analysis Of X-Band Radiation For Space Based Wireless Power Transmission, Noah W. Friz
An Analysis Of X-Band Radiation For Space Based Wireless Power Transmission, Noah W. Friz
Theses and Dissertations
The USAF is interested in developing a solar powered satellite power beaming system using X-Band radiation. To determine the expected level of transmission efficiency of the system, an atmospheric characterization and radiative transfer modeling system called LEEDR was employed. A study was conducted to validate LEEDRs performance while working with microwave frequencies by replicating brightness temperatures measured by a 10.7 GHz radiometer above the Pacific Ocean in 1999. The results were inconclusive. Brightness temperature vs. rain rate curves developed within other studies for X-Band radiation curves could be replicated within LEEDR, and therefore the associated path transmission and extinction values. …
Infiniband Network Monitoring: Challenges And Possibilities, Kyle D. Hintze
Infiniband Network Monitoring: Challenges And Possibilities, Kyle D. Hintze
Theses and Dissertations
Within the realm of High Performance Computing, the InfiniBand Architecture is among the leading interconnects used today. Capable of providing high bandwidth and low latency, InfiniBand is finding applications outside the High Performance Computing domain. One of these is critical infrastructure, encompassing almost all essential sectors as the work force becomes more connected. InfiniBand is not immune to security risks, as prior research has shown that common traffic analyzing tools cannot effectively monitor InfiniBand traffic transmitted between hosts, due to the kernel bypass nature of the IBA in conjunction with Remote Direct Memory Access operations. If Remote Direct Memory Access …
Low-Cost Terrestrial Demonstration Of Autonomous Satellite Proximity Operations, Zackary R. Hewitt
Low-Cost Terrestrial Demonstration Of Autonomous Satellite Proximity Operations, Zackary R. Hewitt
Theses and Dissertations
The lack of satellite servicing capabilities significantly impacts the development and operation of current orbital assets. With autonomous solutions under consideration for servicing, the purpose of this research is to build and validate a low-cost hardware platform to expedite the development of autonomous satellite proximity operations. This research aims to bridge the gap between simulation and existing higher fidelity hardware testing with an affordable alternative. An omnidirectional variant of the commercially available TurtleBot3 mobile robot is presented as a 3-DOF testbed that demonstrates a satellite servicing inspection scenario. Reference trajectories for the scenario are generated via optimal control using the …
Stereo Camera Calibrations With Optical Flow, Joshua D. Larson
Stereo Camera Calibrations With Optical Flow, Joshua D. Larson
Theses and Dissertations
Remotely Piloted Aircraft (RPA) are currently unable to refuel mid-air due to the large communication delays between their operators and the aircraft. AAR seeks to address this problem by reducing the communication delay to a fast line-of-sight signal between the tanker and the RPA. Current proposals for AAR utilize stereo cameras to estimate where the receiving aircraft is relative to the tanker, but require accurate calibrations for accurate location estimates of the receiver. This paper improves the accuracy of this calibration by improving three components of it: increasing the quantity of intrinsic calibration data with CNN preprocessing, improving the quality …
Predicting F-16 Cause Code H Micap Hours Using Jmp Regression Analysis, Scott E. Carr
Predicting F-16 Cause Code H Micap Hours Using Jmp Regression Analysis, Scott E. Carr
Theses and Dissertations
Emergency demands for aircraft parts, MICAPs (Mission Impaired Capability Awaiting Parts) are one of the leading issues affecting mission capability supply rates for fighter aircraft. Cause code H MICAPS, those with a known demand level, but no supply available, are particularly troublesome and difficult to resolve. These MICAPS are due to failures by the supply chain to replenish stock levels within acceptable time limits. Numerous studies have identified a clear need for proactive measures to reduce MICAP hours. This would significantly improve aircraft availability. This study uses regression analysis implemented in JMP software to build models with a goal of …
Ccsfs/Ksc Total Lightning Warning Radii Optimization For Merlin Using Preexisting Lightning Areas, Kimberly G. Holland
Ccsfs/Ksc Total Lightning Warning Radii Optimization For Merlin Using Preexisting Lightning Areas, Kimberly G. Holland
Theses and Dissertations
The purpose of this research is to optimize lightning warning radii specifications for the 45th Space Wing (45 SW), thus reducing the number of unnecessary warnings that delay ground processing needed for space launch execution at Kennedy Space Center and Cape Canaveral Space Force Station. This thesis sought to answer two key research questions addressing: 1) What radius reduction effectively balances both safety and operations and do reduction recommendations from previous research align with results from the new detection system? 2) What insights can be gained from comparing measurement results for seasonal lightning events as well as lightning types? This …
Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer
Examining Crucial Demographic Trends In General Aviation, Joshua D. Meyer
Theses and Dissertations
America's General Aviation sector has witnessed significant demographic shifts since the turn of the century. The number of certified, private pilots, non-fatal aircraft accidents, fatal aircraft accidents, and number of general aviation hours flown are all in decline. Meanwhile, the average age of an American private pilot has increased by several years. All of these factors indicate that the industry is in decline. This study determined via mathematical, linear regression that times relationship to the number of annual, fatal General Aviation accidents and the number of certified private pilots is negative. It also proved that the average age of the …
Application Of Game Theory Based Design To U.S. Space Systems, Benjamin C. Donohoo
Application Of Game Theory Based Design To U.S. Space Systems, Benjamin C. Donohoo
Theses and Dissertations
Modern defense systems are designed to static sets of requirements and specifications. This process has worked well in the past but fails to account for the strategic interdependence of design choices made prior to operating systems. However, as the world becomes increasingly competitive, and as the space domain becomes increasingly congested and contested, such interdependence of design can be described using Game Theory. Game Theory is the mathematical study of strategy, actions and payoffs between rational, self-interested actors. Limited extant research has applied Game Theory to system design but focused on a single system being designed cooperatively within a single …
Model Based Systems Engineering Demonstrator For Air Worthiness With Performance Data Of Department Of Defense Rotorcraft, Bretton M. Bethel
Model Based Systems Engineering Demonstrator For Air Worthiness With Performance Data Of Department Of Defense Rotorcraft, Bretton M. Bethel
Theses and Dissertations
Airworthiness is a process of certifying that an aircraft can be safety operated within specified bounds. This process is essential to ensuring the safety of the aircraft, its personnel, and the surrounding assets. A Model-Based Systems Engineering (MBSE) approach can be utilized as a method to improve the airworthiness process. MBSE is the methodology of creating and utilizing domain models as a means of exchanging and presenting information for a wide variety of disciplines to understand and replacing previous document-based exchange. The objective of this research is to develop a reference architecture with a MBSE approach to perform the airworthiness …
A Reference Architecture For Rapid Cubesat Development, Sean R. Kelly
A Reference Architecture For Rapid Cubesat Development, Sean R. Kelly
Theses and Dissertations
The CubeSat class of nanosatellites has lowered the barrier of entry to space and has rapidly gained popularity in recent years. To successfully design a CubeSat system in a rapid cycle conducive to academic timelines, a Reference Architecture geared towards University CubeSat development would be helpful. A Reference Architecture would speed up the development process by providing a template, capturing previous work and lessons learned from subject matter experts, providing a framework to focus on the CubeSats design rather than the fine details of modeling software. A Reference Architecture can also add functionality that student teams could use and improve …
A Fuzzy Framework For The Air Force Mission Dependency Index, Devin M. Depalmer
A Fuzzy Framework For The Air Force Mission Dependency Index, Devin M. Depalmer
Theses and Dissertations
AFIMSC completed an MDI modernization to support better risk-based decision-making by utilizing tactical mission-owner knowledge to quantify the relationship between facilities and the missions they enable. The resulting facility-mission risk scores leave room for improvement for better use of their intended purposes due to (1) the vulnerability of cognitive biases affecting survey responses due to the use of a traditional risk matrix (2) the lack of resolution between scores from risk ties and (3) the failure to include information from the operational and strategic organizational hierarchy level. This research addresses these concerns through the novel implementation of a fuzzy logic …
An Analysis Of Error Structure And Theoretical First Unit Cost In Learning Curve Theory Models, Alexander D. Pollack
An Analysis Of Error Structure And Theoretical First Unit Cost In Learning Curve Theory Models, Alexander D. Pollack
Theses and Dissertations
The dilemma with learning curves and actual costs is "fitting square pegs into round holes." Alternative regression techniques or further modifications to Y=aXb may address discrepancies in modeling observed data with learning curves. Adequate data permits further analysis of the constants, variables, and factors that make up a learning curve model. The analysis involves trying a nonlinear solver on the traditional learning curve models (i.e., Wright's cumulative average theory and Crawford's unit learning curve theory) and changing the theoretical first unit cost (T1) to the actual first unit cost (A1). Mergers and acquisitions in the aircraft industry may have …
Optimizing Cost And Performance Of Infrastrucure Alternatives At Contingency Bases In A Hub-And-Spoke Network, Kyle J. Rodriguez
Optimizing Cost And Performance Of Infrastrucure Alternatives At Contingency Bases In A Hub-And-Spoke Network, Kyle J. Rodriguez
Theses and Dissertations
Military contingency bases require substantial resources and funding sustain and are often not connected to an infrastructure grid. Infrastructure assets produce the required outputs for sustainment, but are often expensive and inefficient, producing a significant logistical burden. With the increasing near-peer threats of opposing military forces, there is a need for more self-sufficient contingency bases with alternatives that reduce resources usage and the cost of sustainment. Accordingly, the goal of this research is to develop an optimization model capable of selecting infrastructure alternative combinations that minimize the overall resource usage and cost of sustainment at the contingency base level.
Comparison Of Decision Analysis Methods For A Cubesat Propulsion System, Jared L. Pilcher
Comparison Of Decision Analysis Methods For A Cubesat Propulsion System, Jared L. Pilcher
Theses and Dissertations
Low Earth Orbit (LEO) is becoming an increasingly congested orbital regime. As a result, propulsion systems on CubeSats are becoming a more desirable feature to provide them with collision avoidance capabilities. To date, there have been very few CubeSat launches with a propulsion system on them. Due to the relatively high cost of a propulsion system compared to the budget of small educational organizations, a decision analysis model is needed so that these organizations can make the best decision between whether to purchase a Commercial-Off-The-Shelf (COTS) product or to develop one within the organization. This research applies three decision analysis …
Training Subject Matter Experts To Make Better Estimates, Cameron R. Scott
Training Subject Matter Experts To Make Better Estimates, Cameron R. Scott
Theses and Dissertations
Subject Matter Expert (SME) Elicitation is commonly used as a cost-estimation method when no historical data exists. The elicitation process assumes Subject Matter Experts are the resident experts in their individual fields of study. In addition, the process assumes SMEs provide reasonably trustworthy cost estimates that follow the tenets of probability theory. This last assumption is the subject of this study. A Navy sponsored e-learning course was created to help train SMEs in understanding probability distributions (O'Hagan, 2019). We conducted a study hypothesizing that taking the e-learning course would improve study participant accuracy in estimating confidence intervals for probability distributions.
The Effect Of Molar Peroxide Ratio On The Oxidation Of 2,4-Dinitroanisole In An Ultraviolet Light Emitting Diode Advanced Oxidation Process, Troy M. Searcy
The Effect Of Molar Peroxide Ratio On The Oxidation Of 2,4-Dinitroanisole In An Ultraviolet Light Emitting Diode Advanced Oxidation Process, Troy M. Searcy
Theses and Dissertations
Insensitive munitions (IMs) are increasingly employed by the U.S. military to prevent unintended detonations associated with conventional munitions. One IM used extensively is 2,4 dinitroanisole (DNAN). This research employed an ultraviolet light emitting diode (LED) and hydrogen peroxide advanced oxidation process (AOP) to treat DNAN-contaminated water at the laboratory scale. Five molar peroxide ratios (50:1, 100:1, 250:1, 500:1, 1000:1) were evaluated using the observed pseudo first-order rate constant as the performance metric. Both peroxide-limiting reactions and radical scavenging were observed over the range of ratios tested, with overall removal of DNAN decreasing above a ratio of 500:1.
Climate-Informed Prediction And Forecast Modeling Of Installation Total Energy Consumption, Scott C. Weiss
Climate-Informed Prediction And Forecast Modeling Of Installation Total Energy Consumption, Scott C. Weiss
Theses and Dissertations
Climate variability is an external and stochastic factor that causes energy demand uncertainty. Energy managers can use climate-based models to understand future trends of energy demand and to adjust operations, policy, and budgets accordingly. This research focuses on 1) identifying how climate attributes impact energy use, 2) creating a historically informed statistical modeling framework to skillfully predict energy use, and 3) forecasting future changes to energy use and costs, using CMIP5 temperature projections, at the campus level. After synthesizing the existing breadth of research on climate-informed energy modeling, a skillful, unbiased, climate-informed total energy consumption prediction model is developed for …
Aircraft Inspection By Multirotor Uav Using Coverage Path Planning, Patrick H. Silberberg
Aircraft Inspection By Multirotor Uav Using Coverage Path Planning, Patrick H. Silberberg
Theses and Dissertations
All military and commercial aircraft must undergo frequent visual inspections in order to identify damage that could pose a danger to safety of flight. Currently, these inspections are primarily conducted by maintenance personnel. Inspectors must scrutinize the aircraft’s surface to find and document defects such as dents, hail damage, broken fasteners, etc.; this is a time consuming, tedious, and hazardous process. The goal of this work is to develop a visual inspection system which can be used by an Unmanned Aerial Vehicle (UAV), and to test the feasibility of this system on military aircraft. Using an autonomous system in place …
Studying The Conditions For Magnetic Reconnection In Solar Flares With And Without Precursor Flares, Seth H. Garland
Studying The Conditions For Magnetic Reconnection In Solar Flares With And Without Precursor Flares, Seth H. Garland
Theses and Dissertations
Forecasting of solar flares remains a challenge due to the limited understanding of the triggering mechanisms associated with magnetic reconnection, the primary physical phenomenon connected to these events. Consequently, methods continue to rely on the climatology of solar flare events as opposed to the underlying physics principles. Models of magnetic reconnection in the solar atmosphere places the null point of the reconnection within the corona. Though as of now the coronal magnetic field cannot be directly measured, the field is tied to the photospheric magnetic field, which can be. This study utilized data from the Solar Dynamics Observatory Helioseismic and …
Characterization And Analysis Of Bomarc Accident Debris, Aaron J. Heffelfinger
Characterization And Analysis Of Bomarc Accident Debris, Aaron J. Heffelfinger
Theses and Dissertations
Accidents involving nuclear weapons, such as the Boeing Michigan Aeronautical Research Center (BOMARC) accident in 1960, always pose a significant risk of allowing particles composed of nuclear materials to enter the environment. These particles often differ in characteristics and can be of greatly varying sizes. Gamma ray analysis was conducted on the soil sample and radioisotopes within the sample were identified. Two non-destructive methods for locating actinide bearing particles within the sample were testing, resulting in 70 actinide bearing particles ranging from 1-34 microns being identified. These 70 particles underwent both morphological and elemental characterization, indicating uranium and other elements.
Contract Information Extraction Using Machine Learning, Zachary E. Butcher
Contract Information Extraction Using Machine Learning, Zachary E. Butcher
Theses and Dissertations
The Air Force Sustainment Center assisted by the Data Analytics Resource Team and the Defense Logistics Agency collected four million contracts onto one of the Air Force Research Laboratory’s high power computers. This thesis focuses on the effort to determine if parts are available through those contracts. Some information is extracted using machine learning in combination with natural language processing. Where machine learning methods are unsuccessful or inappropriate, text mining techniques, such as pattern recognition and rules, are used. Upon completion, the information is combined into a Gantt chart for quick evaluation. Only 21% of the contracts have their information …
The Obstacles To The Modernization Of Common Support Equipment, J. Erik Ritschard
The Obstacles To The Modernization Of Common Support Equipment, J. Erik Ritschard
Theses and Dissertations
The current fleet of Common Support Equipment (CSE) is faced with a $2B funding disconnect that threatens 9 of the 12 USAF Core Functions. This research identifies the barriers to efforts to modernize CSE across the sustainment, acquisition, and maintenance communities. Using a qualitative, grounded theory methodology, the responses are explored of interviewed Support Equipment managers responsible for the sustainment and modernization of CSE. Significant barriers to current modernization efforts were exposed, resulting in expensive, duplicative, and unreliable equipment; concluding that the AF must change the way CSE is administrated, funded, and culturally understood to prevent future mission degradation.
Defensive Counterair For Air Base Air Defense Using Directed Energy And Kinetic Energy Weapons, Andrew S. Wilson
Defensive Counterair For Air Base Air Defense Using Directed Energy And Kinetic Energy Weapons, Andrew S. Wilson
Theses and Dissertations
Air bases in key locations provide a strategic advantage to the countries that access them, and are at constant threat from adversaries. This research seeks to determine the optimal maneuvering of a fixed number of fighter aircraft in a combat air patrol for defensive counterair to maximally and effectively attrit the inbound cruise missile threat to a stationary high value asset such as an air base. The problem formulation identifies multiple objectives for the model: minimize the distance traveled for the fighters, minimize the time utilized to engage the incoming cruise missiles, and maximize the number of cruise missiles destroyed. …
Developing Infrastructure Adaptation Pathways To Combat Hurricane Intensification: A Coupled Storm Simulation And Economic Modeling Framework For Coastal Installations, Alexander J. Baldwin
Developing Infrastructure Adaptation Pathways To Combat Hurricane Intensification: A Coupled Storm Simulation And Economic Modeling Framework For Coastal Installations, Alexander J. Baldwin
Theses and Dissertations
Climate change projections suggest intensification of extreme weather events, including hurricanes, is expected throughout the 21st century. This will lead to increased destruction for coastal military bases unless infrastructure resiliency and adaptation measures are implemented. This research focuses on examining the simulation of probabilistic, climate-intensified hurricane events at Eglin Air Force Base. FEMA Hazus models are combined with climate projections for wind Intensity, tide, and sea-level rise to produce an assessment of losses to the installation. Damage estimates and hurricane intensity outputs are downscaled to the facility-level so that climate adaptation signals can be identified. The facility losses and climate …
Guidance For Building Motivation In Space Operator Training, Foster E. Davis
Guidance For Building Motivation In Space Operator Training, Foster E. Davis
Theses and Dissertations
Services provided by spacecraft, including communications and global positioning, are integral to small businesses, multinational corporations, and the United States Department of Defense. United States rivals recognize the need to undermine the military advantage provided by the space domain and are exploring ways to degrade these services in their warfare doctrine. In response, the United States will need space systems suited to counter these threats and personnel who are trained to respond to the new reality of a contested space environment. This paper also reviews the academic literature and written guidelines for developing motivation in an interactive environment for improving …