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Articles 1531 - 1560 of 5699
Full-Text Articles in Engineering
Formation Flight Of Earth Satellites On Kam Torus Using Classical Orbital Elements, Marissa C. Reabe
Formation Flight Of Earth Satellites On Kam Torus Using Classical Orbital Elements, Marissa C. Reabe
Theses and Dissertations
This research uses the KAM theory that has been refined by Wiesel to show that Earth-satellites dynamics can be represented by an integrable Hamiltonian system with a small perturbation, like Earths geopotential. The satellite will follow a torus in phase space and remain on that KAM torus for all time unless acted on by a non-conservative force. A torus frequency was calculated, in this research, using a truth model in System Tool Kit (STK) and the High Precision Orbit Propagator (HPOP) to develop an accurate ephemeris file listing the Classical Orbital Elements (COEs). The frequencies found from the truth model …
The Impact Of Atmospheric Fluctuations On Optimal Boost Glide Hypersonic Vehicle Dynamics, Melissa A. Dunkel
The Impact Of Atmospheric Fluctuations On Optimal Boost Glide Hypersonic Vehicle Dynamics, Melissa A. Dunkel
Theses and Dissertations
A project under the management of Air Force Research Laboratory has begun development of a six degree of freedom model for use in hypersonic vehicle development and application. One area of interest is the perturbation of vehicle behavior based on atmospheric fluctuations – how the performance of the vehicle changes with respect to “hot”, “cold” and standard day conditions. The method developed to fill this need uses real-world data from the Global Forecast System to create a “hot” and “cold” day dataset to compare with the standard day model. The key parameter is atmospheric density, a value calculated over a …
Multi-Plc Exercise Environments For Training Ics First Responders, Joseph K. Daoud
Multi-Plc Exercise Environments For Training Ics First Responders, Joseph K. Daoud
Theses and Dissertations
When systems are targeted by cyber attacks, cyber first responders must be able to react effectively, especially when dealing with critical infrastructure. Training for cyber first responders is lacking and most existing exercise platforms are expensive, inaccessible or ineffective. This paper presents a mobile training platform which incorporates a variety of programmable logic controllers into a single system which facilitates the development of the unique skills required of cyber first responders operating in the realm of industrial control systems. The platform is modeled after a jail in the northeastern United States and was developed to maximize realism. Example training scenarios …
A Framework For Categorization Of Industrial Control System Cyber Training Environments, Evan G. Plumley
A Framework For Categorization Of Industrial Control System Cyber Training Environments, Evan G. Plumley
Theses and Dissertations
First responders and professionals in hazardous occupations undergo training and evaluations for the purpose of mitigating risk and damage. For example, helicopter pilots train with multiple categorized simulations that increase in complexity before flying a real aircraft. However in the industrial control cyber incident response domain, where incident response professionals help detect, respond and recover from cyber incidents, no official categorization of training environments exist. To address this gap, this thesis provides a categorization of industrial control training environments based on realism. Four levels of environments are proposed and mapped to Blooms Taxonomy. This categorization will help organizations determine which …
Small Fixed-Wing Aerial Positioning Using Inter-Vehicle Ranging Combined With Visual Odometry, Benjamin M. Fain
Small Fixed-Wing Aerial Positioning Using Inter-Vehicle Ranging Combined With Visual Odometry, Benjamin M. Fain
Theses and Dissertations
There has been increasing interest in developing the ability for small unmanned aerial systems (SUAS) to be able to operate in environments where GPS is not available. This research considers the case of a larger aircraft loitering above a smaller GPS-denied SUAS. This larger aircraft is assumed to have greater resources which can overcome the GPS jamming and provide range information to the SUAS flying a mission below. This research demonstrates that using a ranging update combined with an aircraft motion model and visual odometry can greatly improve the accuracy of a SUASs estimated position in a GPS-denied environment.
Experimental Validation Of A Heterogeneous Radar Clutter Statistical Estimation Method, Elliot R. Erstein
Experimental Validation Of A Heterogeneous Radar Clutter Statistical Estimation Method, Elliot R. Erstein
Theses and Dissertations
Radar clutter models are important for radar target detection when clutter is present. A new method for estimating single clutter type, homogeneous, radar clutter statistics through measurement of a multiple type, heterogeneous clutter was developed in 2015 by researchers at the Air Force Institute of Technology. The estimation method is greatly valued in the clutter research and modeling world for reducing clutter campaign measurement time and cost. This thesis looks at validation steps for the estimation method through the use of simulations and experimental radar clutter measurements.
Autoprov: An Automated File Provenance Collection Tool, Ryan A. Good
Autoprov: An Automated File Provenance Collection Tool, Ryan A. Good
Theses and Dissertations
A file's provenance is a detailing of its origins and activities. There are tools available that are useful in maintaining the provenance of a file. Unfortunately for digital forensics, these tools require prior installation on the computer of interest while provenance generating events happen. The presented tool addresses this by reconstructing a file's provenance from several temporal artifacts. It identifies relevant temporal and user correlations between these artifacts, and presents them to the user. A variety of predefined use cases and real world data are tested against to demonstrate that this software allows examiners to draw useful conclusions about the …
Active Response Using Host-Based Intrusion Detection System And Software-Defined Networking, Jonathon S. Goodgion
Active Response Using Host-Based Intrusion Detection System And Software-Defined Networking, Jonathon S. Goodgion
Theses and Dissertations
This research proposes AHNSR: Active Host-based Network Security Response by utilizing Host-based Intrusion Detection Systems (HIDS) with Software-Defined Networking (SDN) to enhance system security by allowing dynamic active response and reconstruction from a global network topology perspective. Responses include traffic redirection, host quarantining, filtering, and more. A testable SDN-controlled network is constructed with multiple hosts, OpenFlow enabled switches, and a Floodlight controller, all linked to a custom, novel interface for the Open-Source SECurity (OSSEC) HIDS framework. OSSEC is implemented in a server-agent architecture, allowing scalability and OS independence. System effectiveness is evaluated against the following factors: alert density and a …
A Framework For Understanding, Prioritizing, And Applying Systems Security Engineering Processes, Activities, And Tasks, Stephen Khou
A Framework For Understanding, Prioritizing, And Applying Systems Security Engineering Processes, Activities, And Tasks, Stephen Khou
Theses and Dissertations
Current systems security practices lack an effective approach to prioritize and tailor systems security efforts to develop and field secure systems in challenging operational environments, which results in business and mission stakeholders becoming more susceptible to an array of disruptive events. This work informs Systems Engineers on recent developments in the field of system security engineering and provides a framework for more fully understanding the application of Systems Security Engineering (SSE) processes, activities, and tasks as described in the recently released National Institute of Standards and Technology (NIST) Special Publication 800-160. This SSE framework uniquely offers a repeatable and tailorable …
Transient Nonlinear Optical Properties Of Thin Film Titanium Nitride, Sarahkatie Thomas
Transient Nonlinear Optical Properties Of Thin Film Titanium Nitride, Sarahkatie Thomas
Theses and Dissertations
nitride (TiN) and scandium nitride (ScN), using the beam deflection characterization technique. The thin films were made at the Air Force Research Lab by controllably unbalanced magnetron sputtering. Transition metal nitrides, specifically TiN, are used widely in industry because of their unique properties, including extreme hardness and high damage threshold. The properties of thin film transition metal nitrites are dependent on the chemical structure of the thin film, which can be heavily influenced by substrate and deposition method. This durability and tunability is an asset in applications such as sensor protection and all optical computing. Two substrates, sapphire (Al2 …
A Scenario-Based Parametric Analysis Of Stable Marriage Approaches To The Army Officer Assignment Problem, Matthew D. Ferguson
A Scenario-Based Parametric Analysis Of Stable Marriage Approaches To The Army Officer Assignment Problem, Matthew D. Ferguson
Theses and Dissertations
This paper compares linear programming and stable marriage approaches to the assignment problem under conditions of uncertainty. Robust solutions should exhibit reduced variability in the presence of one or more additional constraints. Several variations of each approach are compared with respect to solution quality, as measured by the overall social welfare among Officers and Assignments, and robustness as measured by the number of changes after a number of randomized perturbations. We examine the contrasts between these methods in the context of assigning Army Officers among a set of identified assignments. Additional constraints are modeled after realistic scenarios faced by Army …
Survival Analysis Of Us Air Force Officer Retention Rate, Courtney N. Franzen
Survival Analysis Of Us Air Force Officer Retention Rate, Courtney N. Franzen
Theses and Dissertations
Personnel retention is a matter of great interest in the private and public sectors. In the public sector--specifically the US Air Force--maintaining appropriate retention levels of rated officers is paramount as these officers are the backbone of the Air Force’s mission. As part of the effort to ensure proper retention rates for rated officers, retention models are created by the Air Force Personnel division that assist in predicting future retention patterns and accession needs. The techniques for creating these models, known as the "sustainment line," involve utilizing average retention percentages obtained from historical data. In this study, more statistical-based methods …
Framework For Industrial Control System Honeypot Network Traffic Generation, Htein A. Lin
Framework For Industrial Control System Honeypot Network Traffic Generation, Htein A. Lin
Theses and Dissertations
Defending critical infrastructure assets is an important but extremely difficult and expensive task. Historically, decoys have been used very effectively to distract attackers and in some cases convince an attacker to reveal their attack strategy. Several researchers have proposed the use of honeypots to protect programmable logic controllers, specifically those used to support critical infrastructure. However, most of these honeypot designs are static systems that wait for a would-be attacker. To be effective, honeypot decoys need to be as realistic as possible. This paper introduces a proof-of-concept honeypot network traffic generator that mimics genuine control systems. Experiments are conducted using …
Applying Cyber Threat Intelligence To Industrial Control Systems, Matthew P. Sibiga
Applying Cyber Threat Intelligence To Industrial Control Systems, Matthew P. Sibiga
Theses and Dissertations
A cybersecurity initiative known as cyber threat intelligence (CTI) has recently been developed and deployed. The overall goal of this new technology is to help protect network infrastructures. Threat intelligence platforms (TIPs) have also been created to help facilitate CTI effectiveness within organizations. There are many benefits that both can achieve within the information technology (IT) sector. The industrial control system (ICS) sector can also benefit from these technologies as most ICS networks are connected to IT networks. CTI and TIPs become resourceful when using indicators of compromise (IOCs) from known ICS malware attacks and an open source intrusion detection …
Adsorption Of Perfluorinated Compounds From Post-Emergency Response Wastewater, Christopher T. Schmidt
Adsorption Of Perfluorinated Compounds From Post-Emergency Response Wastewater, Christopher T. Schmidt
Theses and Dissertations
This research investigated the efficacy of granular activated carbon (GAC) as a method to treat water impacted with aqueous film forming foam (AFFF) after a firefighting response. Bench-top experiments were conducted and compared to field scale adsorber performance removing mg/L concentrations of PFAS in water contaminated with Military Specification AFFF. Batch tests compared four adsorbents, and determined Calgon F600 GAC and Rembind Plus mixed carbon media had the greatest perfluorooctane sulfonate (PFOS) capacities. Additional batch isotherm experiments using AFFF and higher PFOS concentrations (mg/L) indicated larger amounts of GAC are required (>30mg/L) for effective removal. Full-scale testing simulated an …
A Framework For Analyzing And Discussing Level Of Human Control Abstraction, Clifford D. Johnson
A Framework For Analyzing And Discussing Level Of Human Control Abstraction, Clifford D. Johnson
Theses and Dissertations
It is often useful to understand the impact of an artificial teammate upon human workload in human-machine teams. Levels of Autonomy (LoA) differentiate systems based on control authority. Unfortunately, human workload is not necessarily correlated with LoA. An alternate classification framework, designated the Level of Human Control Abstraction (LHCA), is proposed. LHCA differentiates system states based on the control and monitoring tasks performed and the level of decisions made by humans. The framework defines five levels, designed to differentiate between system states based upon anticipated levels of human attention. This presentation will summarize the framework and demonstrate its application.
Development Of The Architecture Cost Effectiveness Framework And Application To Open Systems Architectures, Donald A. Barrett
Development Of The Architecture Cost Effectiveness Framework And Application To Open Systems Architectures, Donald A. Barrett
Theses and Dissertations
The Modular Open System Approach (MOSA) is an initiative to, among other things, reduce cost and schedule for acquisitions programs. While programs have experienced savings using MOSA, the majority of programs have not, in part due to a lack of a logical method for evaluating architecture alternatives. This research develops the Architecture Cost Effectiveness Framework (ACEF), which combines multi-attribute utility analysis with cost effectiveness analysis throughout the program lifecycle. Step 1 is the establishment of a business strategy that includes an Attribute Hierarchy of selected operational requirements. The business strategy also defines Lifecycle Utility Reference Profiles (LURPs) that document changing …
A Portfolio Decision Analysis Study For Improving Consequence Of Facility Failure Indices, Michael J. Blaess
A Portfolio Decision Analysis Study For Improving Consequence Of Facility Failure Indices, Michael J. Blaess
Theses and Dissertations
The United States Air Force partially integrated the Mission Dependency Index (MDI) into its portfolio project selection model by assigning an MDI value to a facility type or real property category code (CATCODE) in lieu of assigning a unique MDI value to each facility through a structured interview process. This took an initial step to improve the Air Forces asset management practices; however, it failed to accurately capture the consequence of facility failure in some cases. Although a process to adjudicate the MDI value of individual facilities was created, it is still unknown how much the surveyed MDI value deviates …
Toxicological Differences Between Perfluoroalkyl Substances (Pfas) Isomers Using Developmental Biomarkers, Gabriel A. Cantu
Toxicological Differences Between Perfluoroalkyl Substances (Pfas) Isomers Using Developmental Biomarkers, Gabriel A. Cantu
Theses and Dissertations
Perfluoroalkyl substances (PFAS) are metabolically stable synthetic chemicals that have been manufactured for commercial and industrial purposes since the 1950s. PFAS possess surfactant properties that make them ideal to fight hydrocarbon fires and are therefore present in aqueous film forming foams (AFFF). Furthermore, AFFF may contain blends of both linear and branched PFAS isomers. Research suggests that branched PFAS isomers have greater relative placental transfer efficiencies than their linear counterpart, but few studies have evaluated their toxicity. Therefore, the sustained use of AFFF in the U.S. Air Force presents a risk of branched PFAS exposures in pregnant females. This study …
Enhancing The Thermal Performance Of Temporary Fabric Shelters For The Advanced Energy Efficient Shelter System, Justin E. Eshleman
Enhancing The Thermal Performance Of Temporary Fabric Shelters For The Advanced Energy Efficient Shelter System, Justin E. Eshleman
Theses and Dissertations
Investment in the commercial space industry has grown significantly over the past decade. This investment has led to a tremendous leap in capability for small satellite systems and a greater demand for small launch vehicles. At the same time, space system affordability is a point of emphasis within the Department of Defense (DoD) which raises the question: Can the DoD lower space access costs through the exploitation of the growing small satellite and small launch marketplace? We perform a financial analysis of newly developed small launch vehicles delivering a small satellite constellation to low earth orbit (LEO) to perform wideband …
Learning Curves: An Alternative Analysis, Sharif F. Harris
Learning Curves: An Alternative Analysis, Sharif F. Harris
Theses and Dissertations
Learning curves are used to describe and estimate the cost performance of a serial production process. There are numerous different models and methods, however, it is not definitively known which is preferred. The research objective is to performance compare the more common learning curve models. The research goal is improved understanding of the systemic cost drivers of a production process, their relationship to cost, and present modeling methods. The research method is qualitative analysis combined with statistical regression modeling. The research identified that preference for one function or another depended upon the shape of the data and how well a …
An Empirical Analysis Of Air Force Military Construction Project Delivery Method Performance In The United States, Erich C. Kramer
An Empirical Analysis Of Air Force Military Construction Project Delivery Method Performance In The United States, Erich C. Kramer
Theses and Dissertations
The objective of this study is to investigate the performance of the design-bid-build and design-build project delivery methods in Air Force military construction (MILCON). Project delivery performance is measured through quantitative cost, schedule, and change order metrics for 264 design-bid-build and 316 design-build MILCON projects from 2003-2014. The average response measures were statistically compared within each delivery method using three independent variables: time, facility type, and major command (MAJCOM). The historical analysis revealed that the current working estimate programmed amount ratios improved over time for design-build projects, and an overall consistency in schedule growth and project duration performance occurred across …
Feasibility And Environmental Implications Of Using Waste Motor Oil As Alternative Supplemental Fuel In Contingency Prime Power Generation, Zachary S. Bierhaus
Feasibility And Environmental Implications Of Using Waste Motor Oil As Alternative Supplemental Fuel In Contingency Prime Power Generation, Zachary S. Bierhaus
Theses and Dissertations
In an era of strict hazardous material restrictions and intense energy savings projects, DoD has an opportunity for a waste-to-energy initiative by looking to vintage diesel engine technology for inspiration. The idea comes in the form of recycled Waste Motor Oil (WMO) which can be used as a fuel in compression-ignition engines. When mixed at a low blend ratio, WMO can supplement diesel fuels to extend the range of fuel stores for electrical power generating equipment at contingency military bases while simultaneously decreasing the burden on fuel supply chain management and the hazardous waste disposal stream. This research looked at …
Application Of Enlisted Force Retention Levels And Career Field Stability, Jamie T. Zimmermann
Application Of Enlisted Force Retention Levels And Career Field Stability, Jamie T. Zimmermann
Theses and Dissertations
The Air Force’s success is influenced by the manpower it has. The end-strength is Congressionally mandated. Predicting personnel retention is critical to the operations of the military. Over 10 years ago, the Air Force produced enlisted career field sustainment lines based on manning. If a career field was over manned the authorizations were decreased, likewise if a career field was under manned the authorizations were increased. The constant fluctuation of manning caused bathtubs to be created and requirements to go unfilled. Currently, the Air Force produces enlisted career field sustainment lines based on the 5-year historical retention rates. This method …
The Impacts Of Climate Change And Anthropogenic Processes On Permafrost Soils And Usaf Infrastructure Within Northern Tier Bases, Alexander J. Graboski
The Impacts Of Climate Change And Anthropogenic Processes On Permafrost Soils And Usaf Infrastructure Within Northern Tier Bases, Alexander J. Graboski
Theses and Dissertations
The Department of Defense is planning over $552M in military construction on Eielson Air Force Base within the next three fiscal years. Although many studies have been conducted on permafrost and climate change, the future of our climate as well as any impacts on permafrost soils, remains unclear. This research focused on future climate predictions to determine likely scenarios for the United States Air Force’s Strategic Planners to consider. The most recent 2013 International Panel on Climate Change report predicts a 2.2ºC to 7.8ºC temperature rise in Arctic regions by the end of the 21st Century in the Representative Concentration …
Optimal Configurations For Aerosol Monitoring With Multi-Rotor Small Unmanned Aerial Systems, Inna D. Chavez
Optimal Configurations For Aerosol Monitoring With Multi-Rotor Small Unmanned Aerial Systems, Inna D. Chavez
Theses and Dissertations
Applicability of aerosol sampling on multi-rotor unmanned aerial systems (UAS) platform was investigated. Multi-rotor UAS have impacts of wind speed, turbulence, and orientation possibly contributing to sampling bias. The SKC IMPACT sampler, Tecora C.A.Th.I.A., and modified three-dimensionally printed Universal Inlet for Airborne-Particle Size-Selective Sampling were selected based on particle size-selectivity and operational independence to wind. Airflow visualizations concluded that below UAS fuselage was optimal sampler placement. Tests were conducted with Arizona Road Dust in a still-air chamber, and aerosolized sugar in a wind tunnel. Inlet mounting was evaluated in, upright, upside-down, and horizontal orientations. Horizontal orientations of all inlets resulted …
Military Space Mission Design And Analysis In A Multi-Body Environment: An Investigation Of High-Altitude Orbits As Alternative Transfer Paths, Parking Orbits For Reconstitution, And Unconventional Mission Orbits, John N. Brick
Theses and Dissertations
High-altitude satellite trajectories are analyzed in the Earth-Moon circular restricted three-body problem. The equations of motion for this dynamical model possess no known closed-form analytical solution; therefore, numerical methods are employed. To gain insight into the dynamics of high-altitude trajectories in this multi-body dynamical environment, periapsis Poincare' maps are generated at particular values of the Jacobi Constant. These maps are employed as visual aids to generate initial guesses for orbital transfers and to determine the predictability of the long term behavior of a spacecraft's trajectory. Results of the current investigation demonstrate that high-altitude transfers may be performed for comparable, and …
Optimal Design Of A Hexakis Icosahedron Vacuum Based Lighter Than Air Vehicle, Joseph R. Schwemmer
Optimal Design Of A Hexakis Icosahedron Vacuum Based Lighter Than Air Vehicle, Joseph R. Schwemmer
Theses and Dissertations
Due to the rising cost and scarcity of helium, new methods to ensure buoyancy for lighter-than-air vehicles (LTAVs) are being sought. One alternative under study uses an internal vacuum to reduce the weight to buoyancy ratio. It's a novel approach; however, the vacuum presents challenges for the vehicle's structure. The structure must have minimum mass while preventing buckling and excess stress throughout the frame and membrane. The structure under analysis is a hexakis icosahedron with a membrane covering. Achieving minimum mass involves optimizing the structure under the loading conditions. Finite-element analysis (FEA) and direct-search methods are employed, providing an optimal …
2018 Military Retirement Options: An Expected Net Present Value Decision Analysis Model, Bret N. Witham
2018 Military Retirement Options: An Expected Net Present Value Decision Analysis Model, Bret N. Witham
Theses and Dissertations
The 2016 NDAA authorized changes to the military retirement system transitioning from the legacy High-3 defined benefit annuity to the new Blended Retirement System (BRS). In exchange for a reduced defined benefit annuity, the BRS incorporates automatic and matching contributions to the member’s Thrift Savings Plan and a continuation payment offered at 12 years of service. In 2018,service members with less than 12 years of service will make an irrevocable decision between the two retirement systems. This research effort addresses the problem by developing a decision analysis model incorporating up to 27 different input variables. Service members can use the …
Reliability And Cost Impacts For Attritable Systems, Bryan R. Bentz
Reliability And Cost Impacts For Attritable Systems, Bryan R. Bentz
Theses and Dissertations
Attritable systems trade system attributes like reliability and reparability to achieve lower acquisition cost and decrease cost risk. Ultimately, it is hoped that by trading these attributes the amount of systems able to be acquired will be increased. However, the effect of trading these attributes on system-level reliability and cost risk is difficult to express complicated reparable systems like an air vehicle. Failure-time and cost data from a baseline limited-life air vehicle is analyzed for this reliability and reparability trade study. The appropriateness of various reliability and cost estimation techniques are examined for these data. This research employs the cumulative …