Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2017

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 4591 - 4620 of 8353

Full-Text Articles in Engineering

Feasibility And Environmental Implications Of Using Waste Motor Oil As Alternative Supplemental Fuel In Contingency Prime Power Generation, Zachary S. Bierhaus Mar 2017

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 …

Go to article

The Impacts Of Climate Change And Anthropogenic Processes On Permafrost Soils And Usaf Infrastructure Within Northern Tier Bases, Alexander J. Graboski Mar 2017

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 …

Go to article

United States Air Force Unaccompanied Housing Divestiture: An Economic Analysis, Dustin L. Gooden Mar 2017

United States Air Force Unaccompanied Housing Divestiture: An Economic Analysis, Dustin L. Gooden

Theses and Dissertations

The objective of this research is to determine potential cost savings associated with Air Force unaccompanied housing divestiture. This research uses Air Education and Training Command (AETC) installations as the data sample for the analysis, and will analyze the status quo, privatization, and identical FSRM options. With 16% of Air Force unaccompanied housing currently rated at various levels of inadequacy and the PRV for the inadequate housing at $2,315,773,149.00, the costs associated with renovating the inadequate unaccompanied housing is substantial. Moreover, the inadequacy of unaccompanied housing is part of the Air Force’s acceptance of risk in facilities and infrastructure to …

Go to article

Resource Evaluation Of Quantum Linear Systems Algorithm For Application To Electromagnetic Scattering Problems, Casey J.R. Riggs Mar 2017

Resource Evaluation Of Quantum Linear Systems Algorithm For Application To Electromagnetic Scattering Problems, Casey J.R. Riggs

Theses and Dissertations

Current limitations in quantum computing technology does not allow for very large applications of quantum algorithms, and it is the nature of quantum algorithms not only to be able to solve problems of interest much more quickly than classical means but also to do so with less resources which makes them so promising! One such problem of interest is the application of the Quantum Linear Systems Algorithm, along with a few other subroutines, to the calculation of an electromagnetic scattering cross-section via finite element methods. This work composes a resource analysis of the algorithm as well as required subroutines and …

Go to article

Adsorption Of Perfluorinated Compounds From Post-Emergency Response Wastewater, Christopher T. Schmidt Mar 2017

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 …

Go to article

Computational Optimization Under Uncertainty Of An Active Flow Control Jet, Luke A. Welch Mar 2017

Computational Optimization Under Uncertainty Of An Active Flow Control Jet, Luke A. Welch

Theses and Dissertations

Optimization under uncertainty is performed to determine the optimal parameters of an active flow control jet to impart robust control during transonic cruise. A steady blowing jet is optimized on an airfoil to impart a change in lift greater than or equal to that generated by traditional control surfaces. The design candidates are computationally evaluated using the NASA flow solver, FUN3D, under 20 unique combinations of angle of attack, Reynolds number, and Mach number in order to propagate model input uncertainty. The mean change in lift and the associated standard deviation are included in the optimization framework to help ensure …

Go to article

Multi-Plc Exercise Environments For Training Ics First Responders, Joseph K. Daoud Mar 2017

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 …

Go to article

Small Fixed-Wing Aerial Positioning Using Inter-Vehicle Ranging Combined With Visual Odometry, Benjamin M. Fain Mar 2017

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.

Go to article

Experimental Validation Of A Heterogeneous Radar Clutter Statistical Estimation Method, Elliot R. Erstein Mar 2017

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.

Go to article

Autoprov: An Automated File Provenance Collection Tool, Ryan A. Good Mar 2017

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 …

Go to article

Active Response Using Host-Based Intrusion Detection System And Software-Defined Networking, Jonathon S. Goodgion Mar 2017

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 …

Go to article

Combined Stereo Vision And Inertial Navigation For Automated Aerial Refueling, Daniel T. Johnson Mar 2017

Combined Stereo Vision And Inertial Navigation For Automated Aerial Refueling, Daniel T. Johnson

Theses and Dissertations

This paper describes the design of an EKF to obtain the precise relative position of two aircraft in a refueling maneuver while operating in GPS denied environments. The EKF uses the INS already present in both aircraft as well as the stereo camera system organic to new tanker systems. The aircraft trajectories are generated according to authentic refueling profiles with flight dynamics software and executed in a 3D virtual environment to enable deterministic simulation of the stereo camera system and to demonstrate the effectiveness of the combined system in a refueling scenario. Results show the system can achieve sufficient accuracy …

Go to article

A Framework For Understanding, Prioritizing, And Applying Systems Security Engineering Processes, Activities, And Tasks, Stephen Khou Mar 2017

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 …

Go to article

An Empirical Analysis Of Air Force Military Construction Project Delivery Method Performance In The United States, Erich C. Kramer Mar 2017

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 …

Go to article

Development Of The Architecture Cost Effectiveness Framework And Application To Open Systems Architectures, Donald A. Barrett Mar 2017

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 …

Go to article

Toxicological Differences Between Perfluoroalkyl Substances (Pfas) Isomers Using Developmental Biomarkers, Gabriel A. Cantu Mar 2017

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 …

Go to article

Enhancing The Thermal Performance Of Temporary Fabric Shelters For The Advanced Energy Efficient Shelter System, Justin E. Eshleman Mar 2017

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 …

Go to article

Learning Curves: An Alternative Analysis, Sharif F. Harris Mar 2017

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 …

Go to article

Alternate Stimuli For The Elicitation Of Event-Related Potentials, Bryan V. Jackson Mar 2017

Alternate Stimuli For The Elicitation Of Event-Related Potentials, Bryan V. Jackson

Theses and Dissertations

Brain-Computer Interfaces (BCIs) are systems that leverage user-brain activity to identify and perform specific functions. In applications requiring overt visual attention, focusing on visual stimuli with known temporal variation can elicit measurable changes in brain activity. However, elements of BCI applications can be intrusive. This research was designed to determine if Event-Related Potentials (ERPs), to include Steady-State Visually-Evoked Potentials (SSVEPs), could be elicited and interpreted from less obtrusive stimuli. Specifically, this research explores the use of variable frequency and long-wavelength (infrared) stimuli for SSVEP interpretation to explore the application of less obtrusive stimuli for application in BCIs. It was determined …

Go to article

A Framework For Analyzing And Discussing Level Of Human Control Abstraction, Clifford D. Johnson Mar 2017

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.

Go to article

An Investigation Into The Indicators Of A Successful Total Force Association, Greg E. Hoyt Mar 2017

An Investigation Into The Indicators Of A Successful Total Force Association, Greg E. Hoyt

Theses and Dissertations

The Air Force, since adopting and subsequently developing the Total Force concept in the early 1970s, has not thoroughly outlined clear objectives by which the progress toward and realization of this strategic vision should be defined and measured. Without clear definition, direction, and method of evaluation, the ability to credibly claim any subsequent successes or failures in the pursuit of this vision become vulnerable to challenge. Indeed, the mere claim that a single, clear vision exists may be challenged. The Total Force concepts degree of success has, on multiple occasions through its history, been critiqued with the most recent instance …

Go to article

Real-Time Heuristic Algorithms For The Static Weapon-Target Assignment Problem, Alexander G. Kline Mar 2017

Real-Time Heuristic Algorithms For The Static Weapon-Target Assignment Problem, Alexander G. Kline

Theses and Dissertations

The problem of targeting and engaging individual missiles (targets) with an arsenal of interceptors (weapons) is known as the weapon target assignment problem. As many solution techniques are based upon a transformation of the objective function, their final solutions rarely produce optimal solutions. We propose a nonlinear branch and bound algorithm to provide the first optimization approach to the untransformed problem found in the literature. Further, we propose a new heuristic based upon the branch and bound algorithm which dominates other heuristics explored in optimality gap. We also propose a heuristic based upon the optimal solution to the quiz problem …

Go to article

Predicting Solar Performance In A Contingency Environment To Meet Net-Zero Facility Power, Anthony D. Williams Mar 2017

Predicting Solar Performance In A Contingency Environment To Meet Net-Zero Facility Power, Anthony D. Williams

Theses and Dissertations

The U.S. government is involved in contingency operations all over the world and these operations require operational support and sustainment in these locations; this includes the reliable delivery of power to base infrastructure. The traditional means of delivering this support requirement in austere environments has been the use of diesel-power generation that has an extensive logistical and economic tail. The research sought out contingency solar applications that may be implemented and operated to offset the facility demand loads in the location to achieve net-zero power. This research explores the technical feasibility of a deployable photovoltaic microgrid to deliver power to …

Go to article

The Impact Of Atmospheric Fluctuations On Optimal Boost Glide Hypersonic Vehicle Dynamics, Melissa A. Dunkel Mar 2017

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 …

Go to article

A System Dynamics Model Investigating The Efficacy Of Non-Kinetic Policy Strategies On The Diffusion Of Democratic Ideologies In China, Maria S. Phillips Mar 2017

A System Dynamics Model Investigating The Efficacy Of Non-Kinetic Policy Strategies On The Diffusion Of Democratic Ideologies In China, Maria S. Phillips

Theses and Dissertations

Shaping the next century of global politics and power, United States-China relations comprise one of the most significant bilateral relationships in the world. A new era of unrestricted warfare is one example of how aggression from China could be very costly for the United States. The growth of democratic ideals within China decreases the risk of detrimental impacts according to democratic peace theory. This thesis explores a multifaceted system of relationships that regulate the diffusion of democratic ideology within China, as defined by a proxy-measure characterized as human rights by Freedom House. Relative deprivation theory coupled with an adapted Bass …

Go to article

An Approximate Dynamic Programming Approach For Comparing Firing Solutions In A Networked Air Defense Environment, Daniel S. Summers Mar 2017

An Approximate Dynamic Programming Approach For Comparing Firing Solutions In A Networked Air Defense Environment, Daniel S. Summers

Theses and Dissertations

The United States Army currently employs a shoot-shoot-look firing policy for air defense. As the Army moves to a networked defense-in-depth strategy, this policy will not provide optimal results for managing interceptor inventories in a conflict to minimize the damage to defended assets. The objective for air and missile defense is to identify the firing policy for interceptor allocation that minimizes expected total cost of damage to defended assets. This dynamic weapon target assignment problem is formulated first as a Markov decision process (MDP) and then approximate dynamic programming (ADP) is used to solve problem instances based on a representative …

Go to article

An Analysis Of Radio-Frequency Geolocation Techniques For Satellite Systems Design, Daniel R. Barnes Mar 2017

An Analysis Of Radio-Frequency Geolocation Techniques For Satellite Systems Design, Daniel R. Barnes

Theses and Dissertations

This research 1) evaluates the effectiveness of CubeSat radio-frequency geolocation and 2) analyzes the sensitivity of different RF algorithms to system parameters. A MATLAB simulation is developed to assess geolocation accuracy for variable system designs and techniques (AOA, TDOA, T/FDOA). An unconstrained maximum likelihood estimator (MLE) and three different digital elevation models (DEM) are utilized as the surface of the Earth constraint to improve geolocation accuracy. The results presented show the effectiveness of the MLE and DEM techniques, the sensitivity of AOA, TDOA, and T/FDOA algorithms, and the system level performance of a CubeSat geolocation cluster in a 500km circular …

Go to article

Analysis Of Additively Manufactured Lattice Structures Using Finite Element Methods, Christopher A. Box Mar 2017

Analysis Of Additively Manufactured Lattice Structures Using Finite Element Methods, Christopher A. Box

Theses and Dissertations

Additive Manufacturing (AM) processes are well known for their ability to fabricate parts with complex geometries. Lattice structures leverage this ability to create parts with high strength-to-weight ratio and other desirable structural qualities. This research presents a parameterized modeling tool using common Finite Element Analysis (FEA) and scripting software with which aggregated lattice structures can be analyzed, given different geometric properties and loading conditions. A full factorial Design of Experiments is run to explore the effects of various parameters on the strength of lattice structures. Experimental compressive strength results from three FDM-produced PLA lattices are discussed and compared to predictions …

Go to article

Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite At 1200°C In Air And In Steam, Nicholas J. Boucher Mar 2017

Fatigue Behavior Of An Advanced Melt-Infiltrated Sic/Sic Composite At 1200°C In Air And In Steam, Nicholas J. Boucher

Theses and Dissertations

The tension-tension fatigue behavior of an advanced melt-infiltrated (MI) silicon carbide/silicon carbide (SiC/SiC) ceramic matrix composite (CMC) was investigated at 1200 degrees Celsius in air and in steam. The MI composite consisted of ten 0/90 plies of Hi-Nicalon-S SiC fibers woven in a five harness satin weave (5HSW), a CVI BN interphase to provide a weak fiber-matrix interphase, and a CVI SiC matrix layer followed by infiltration with SiC particulate slurry and molten silicon. Nine tensile specimens of the material were used in a pilot investigation of mechanical performance at elevated temperature. One specimen was used in a monotonic tensile …

Go to article

Investigation Of Dynamic Store Separation Out Of A Weapons Bay Cavity Utilizing A Low Speed Wind Tunnel, Andrew D. Bower Mar 2017

Investigation Of Dynamic Store Separation Out Of A Weapons Bay Cavity Utilizing A Low Speed Wind Tunnel, Andrew D. Bower

Theses and Dissertations

Characterizing mission store trajectories as they separate from a weapons bay cavity is highly relevant to the Air Force mission. The flow around a weapons bay is unsteady. The unsteady flow can cause a mission store separation trajectory to be unpredictable, and such is the case for what some have termed a pitch bifurcation. Traditional wind tunnel testing is incapable of detecting a bifurcation because traditional wind tunnel testing records time-averaged data. In this study, an experimental testing system was developed and refined in order to support the time-accurate characterization of dynamic mission store separation events. A Motion Test Apparatus …

Go to article

First Prev Next Last