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Multi-Objective Optimization Of Mixed-Variable, Stochastic Systems Using Single-Objective Formulations, Todd J. Paciencia
Multi-Objective Optimization Of Mixed-Variable, Stochastic Systems Using Single-Objective Formulations, Todd J. Paciencia
Theses and Dissertations
Many problems exist where one desires to optimize systems with multiple, often competing, objectives. Further, these problems may not have a closed form representation, and may also have stochastic responses. Recently, a method expanded mixed variable generalized pattern search/ranking and selection (MVPS-RS) and Mesh Adaptive Direct Search (MADS) developed for single-objective, stochastic problems to the multi-objective case by using aspiration and reservation levels. However, the success of this method in approximating the true Pareto solution set can be dependent upon several factors. These factors include the experimental design and ranges of the aspiration and reservation levels, and the approximation quality …
Using Hierarchical Temporal Memory For Detecting Anomalous Network Activity, Gerod M. Bonhoff
Using Hierarchical Temporal Memory For Detecting Anomalous Network Activity, Gerod M. Bonhoff
Theses and Dissertations
This thesis explores the nature of cyberspace and forms an argument for it as an intangible world. This research is motivated by the notion of creating intelligently autonomous cybercraft to reside in that environment and maintain domain superiority. Specifically, this paper offers 7 challenges associated with development of intelligent, autonomous cybercraft. The primary focus is an analysis of the claims of a machine learning language called Hierarchical Temporal Memory (HTM). In particular, HTM theory claims to facilitate intelligence in machines via accurate predictions. It further claims to be able to make accurate predictions of unusual worlds, like cyberspace. The research …
Tightly Integrating Optical And Inertial Sensors For Navigation Using The Ukf, Sedat Ebcin
Tightly Integrating Optical And Inertial Sensors For Navigation Using The Ukf, Sedat Ebcin
Theses and Dissertations
The motivation of this research is to address the benefits of tightly integrating optical and inertial sensors where GNSS signals are not available. The research begins with describing the navigation problem. Then, error and measurement models are presented. Given a set of features, a feature detection and projection algorithm is developed which utilizes inertial measurements to predict vectors in the feature space between images. The unscented Kalman filter is applied to the navigation system using the inertial measurements and feature matches to estimate the navigation trajectory. Finally, the image-aided navigation algorithm is tested using a simulation and an experiment. As …
Analysis Of Non-Uniform Gain For Control Of A Deformable Mirror In An Adaptive-Optics System, Kevin P. Vitayaudom
Analysis Of Non-Uniform Gain For Control Of A Deformable Mirror In An Adaptive-Optics System, Kevin P. Vitayaudom
Theses and Dissertations
The Air Force Research Laboratory’s Sodium Guidestar Adaptive Optics for Space Situational Awareness program (NGAS) has sponsored research on spatially non-uniform gain for the servo-loop controller of an adaptive optics (AO) system. The edge subapertures of a Shack-Hartmann wavefront sensor have lower signal-to-noise ratios and are more susceptible to measurement errors than fully illuminated center subapertures. These measurement errors produce errant commands over the corresponding edge actuators and can induce instabilities over these regions in strong turbulence conditions. The objective of this research was to develop and experimentally verify the use of spatially varying gain maps on the servo-loop controller …
Scramjet Fuel Injection Array Optimization Utilizing Mixed Variable Pattern Search With Kriging Surrogates, Bryan Sparkman
Scramjet Fuel Injection Array Optimization Utilizing Mixed Variable Pattern Search With Kriging Surrogates, Bryan Sparkman
Theses and Dissertations
Fuel-air mixing analysis of scramjet aircraft is often performed through ex- perimental research or Computational Fluid Dynamics (cfd) algorithms. Design optimization with these approaches is often impossible under a limited budget due to their high cost per run. This investigation uses jetpen, a known inexpensive analysis tool, to build upon a previous case study of scramjet design optimization. Mixed Variable Pattern Search (mvps) is compared to evolutionary algorithms in the optimization of two scramjet designs. The ¯rst revisits the previously stud- ied approach and compares the quality of mvps to prior results. The second applies mvps to a new scramjet …
What Constitutes An Act Of War In Cyberspace, Kelli S. Kinley
What Constitutes An Act Of War In Cyberspace, Kelli S. Kinley
Theses and Dissertations
In December 2005 a new mission statement was released by the Air Force Leadership, "to deliver sovereign options for the defense of the United States of America and its global interests...to fly and fight in Air, Space and Cyberspace." (Wynne & Mosley, 2005) With the stand up of the AFCYBER command and the use of cyberspace to carry out our daily mission the U.S. needs to have a clear understanding of what war in cyberspace looks like and what the laws are governing war in cyberspace. This research and it's resulting data analysis is intended to provide a better understanding …
Development Of A Screening Tool To Facilitate Technology Of An Innovative Technology To Treat Perchlorate-Contaminated Water, Daniel A. Craig
Development Of A Screening Tool To Facilitate Technology Of An Innovative Technology To Treat Perchlorate-Contaminated Water, Daniel A. Craig
Theses and Dissertations
Perchlorate contamination of drinking water is a significant problem nationwide. The purpose of this study was to develop a tool to predict the cost and performance of tailored granular activated carbon (T-GAC), an innovative technology that is being evaluated as a cost-effective treatment for perchlorate-contaminated water. The ability to accurately predict performance and cost can facilitate the transfer and commercialization of innovative technologies. In the study, a model was developed to predict T-GAC performance and life-cycle costs for removing perchlorate under varying influent water quality and technology operating conditions. The model's design parameters were obtained from laboratory rapid small-scale column …
A System Dynamic Model Of Leader Emergence, Paul S. Wever
A System Dynamic Model Of Leader Emergence, Paul S. Wever
Theses and Dissertations
The purpose of this thesis is to develop a system dynamics model of leader emergence. Longitudinal social network and personality data were collected in a class of enlisted military professionals attending a 6-week leadership development course. Findings support known relationships in existing leadership research. The thesis demonstrates the applicability of system dynamics toward the complex social phenomena of leader emergence.
An Evaluation And Implementation Guide For Current Groundwater Mass Flux Measurement Practices, Jack G. Wheeldon Iii
An Evaluation And Implementation Guide For Current Groundwater Mass Flux Measurement Practices, Jack G. Wheeldon Iii
Theses and Dissertations
Contaminant mass flux is an important parameter needed for decision making at sites with contaminated groundwater. New and potentially better methods for measuring mass flux are emerging. This study looks at the conventional transect method (TM), and the newer passive flux meter (PFM), modified integral pump test (MIPT), and tandem circulating well (TCW) methods. In order to facilitate transfer and application of these innovative technologies, it is essential that potential technology users have access to credible information that addresses technology capabilities, limitations, and costs. This study provides such information on each of the methods by reviewing implementation practices and comparing …
Comparing Information Assurance Awareness Training For End-Users: A Content Analysis Examination Of Air Force And Defense Information Systems Agency User Training Modules, John W. Frugé
Theses and Dissertations
Today, the threats to information security and assurance are great. While there are many avenues for IT professionals to safeguard against these threats, many times these defenses prove useless against typical system users. Mandated by laws and regulations, all government agencies and most private companies have established information assurance (IA) awareness programs, most of which include user training. Much has been given in the existing literature to laying out the guidance for the roles and responsibilities of IT professionals and higher level managers, but less is specified for "everyday" users of information systems. This thesis attempts to determine the content …
Improving Mixed Variable Optimization Of Computational And Model Parameters Using Multiple Surrogate Functions, David Bethea
Improving Mixed Variable Optimization Of Computational And Model Parameters Using Multiple Surrogate Functions, David Bethea
Theses and Dissertations
This research focuses on reducing computational time in parameter optimization by using multiple surrogates and subprocess CPU times without compromising the quality of the results. This is motivated by applications that have objective functions with expensive computational times at high fidelity solutions. Applying, matching, and tuning optimization techniques at an algorithm level can reduce the time spent on unprofitable computations for parameter optimization. The objective is to recover known parameters of a flow property reference image by comparing to a template image that comes from a computational fluid dynamics simulation, followed by a numerical image registration and comparison process. Mixed …
A Delphi Study Assessing Long-Term Access To Electronic Medical Records (Emr), Byron D. Nicholson
A Delphi Study Assessing Long-Term Access To Electronic Medical Records (Emr), Byron D. Nicholson
Theses and Dissertations
This research effort addressed the issue of long-term access to electronic medical records as technological generations become obsolete, thereby preventing the access to patient health information. Using the Delphi methodology, experts with experience in electronic medical records and applicable systems provided insight based on their years of hands-on experience managing and/or using records and these systems. The end result of this research was a collection of ideas that medical institutions and medical informaticians must consider to ensure that patients and hospitals do not lose long-term access to electronic medical records as electronic medical records and technology continually evolves. Results of …
Suspicion Modeling In Support Of Cyber-Influence Operations/Tactics, Henry G. Paguirigan
Suspicion Modeling In Support Of Cyber-Influence Operations/Tactics, Henry G. Paguirigan
Theses and Dissertations
Understanding the cognitive process of IT user suspicion may assist organizations in development of network protection plans, personnel training, and tools necessary to identify and mitigate nefarious intrusions of IT systems. Exploration of a conceptual common ground between psycho-social and technology-related concepts of suspicion are the heart of this investigation. The complexities involved in merging these perspectives led to the overall research question: What is the nature of user suspicion toward IT: The research problem/phenomenon was addressed via extensive literature review, and use of the Interactive Qualitative Analysis problem/phenomenon. Analysis of the system led to the development of a model …
Estimation Of The Number Of Microbial Species Comprising A Population, Melanie R. Slattery
Estimation Of The Number Of Microbial Species Comprising A Population, Melanie R. Slattery
Theses and Dissertations
The purpose of this research was to evaluate the appropriateness of using non-parametric estimators, specifically the Chao1, ACES, and Jackknife methods, for estimation of the number of unique species comprising a population. It goes on to develop a parametric method for the above stated problem. This research consisted of creating diverse populations, with known numbers of species, and applying the aforementioned non-parametric and parametric methods to samples drawn from the constructed populations. The parametric fitting of several different distributions to the sample data, including the lognormal, gamma, and Weibull was considered. Both types of methodologies were then applied to sample …
Three Models Of Anthrax Toxin Effects On The Map-Kinase Pathway And Macrophage Survival, Daniel J. Schneider
Three Models Of Anthrax Toxin Effects On The Map-Kinase Pathway And Macrophage Survival, Daniel J. Schneider
Theses and Dissertations
Lethal factor (LF), a component of anthrax toxin, is the primary virulence factor that allows Bacillus anthracis to evade the immune response by blocking the activation of mitogen-activated protein kinase (MAPK) enzymes. This research modifies three published MAPK models to reflect this signal inhibition and to estimate a first-order reaction rate by fitting the models to published viability data for two macrophage cell lines cultured with the LF-producing Bacillus anthracis-Vollum1B strain. One model appears to be ill-suited for this purpose because not all relevant MAPK components could be integrated into the inhibition equations. Despite different underlying parameters and values, the …
Micro-Etched Platforms For Thermal Inactivation Of Bacillus Anthracis And Bacillus Thuringiensis Spores, Leslie S. Hawkins
Micro-Etched Platforms For Thermal Inactivation Of Bacillus Anthracis And Bacillus Thuringiensis Spores, Leslie S. Hawkins
Theses and Dissertations
This research developed and applied microlithography techniques to etch microscope slide platforms in order to measure thermal inactivation of Bacillus thuringiensis and Bacillus anthracis spores, two closely related Bacillus species. B.t. is widely used as a surrogate for B.a. in response studies and in some field studies. This work addressed the previously identified problem of measuring both spore growth and spore thermal kill threshold using the traditional method of spreading a diluted spore solution on a plate. The micro-etched platforms forced spore separation thereby preventing neighbor growth from obscuring germination and initial vegetative growth measurements using a microscope. The technique …
Ionospheric Response To Solar Flares Using An Improved Version Of Sami2, Joseph P. Reich Iii
Ionospheric Response To Solar Flares Using An Improved Version Of Sami2, Joseph P. Reich Iii
Theses and Dissertations
Solar flares release energy, primarily at X-ray and EUV wavelengths, which is then absorbed mainly in Earth's ionosphere. This non-uniform absorption of energy alters the ionosphere's structure and can change the propagation of electromagnetic waves causing errors in GPS navigation, false radar echoes, and loss of High Frequency (HF) radio communications. Accurately modeling the ionospheric response to flares is the first step in predicting, and then mitigating, their effects. Accurately modeling these effects requires solar irradiance at a high cadence, to capture the flare, which may only last minutes, as well as treatment of the effects of photoelectrons. Sami2 is …
An Analysis Of Competencies For Managing Science And Technology Programs, Sidney W. Goehring
An Analysis Of Competencies For Managing Science And Technology Programs, Sidney W. Goehring
Theses and Dissertations
The purpose of this research is to analyze competencies needed for successful program management of Research and Development (R&D) programs -- also known as Science and Technology (S&T) programs -- within the Department of Defense (DoD). Current competency models are in development for the DoD Acquisition, Technology, and Logistics (AT&L) functional areas. Using an interim competency model developed for the Program Manager career field comprised of 36 technical competencies and 27 professional competencies, the research compares competencies' criticality scores rated by traditional acquisition program managers (PMs) with those rated by S&T program managers. In 42 out of 63 instances (67%), …
A Case-Based Exploration Of Task/Technology Fit In A Knowledge Management Context, Michael W. Moseley
A Case-Based Exploration Of Task/Technology Fit In A Knowledge Management Context, Michael W. Moseley
Theses and Dissertations
Task/Technology Fit (TTF) posits that as the intersection of the task domain and the capabilities of an information system (IS) increases in magnitude, the performance gains experienced by user through use of the IS will be positively impacted. While rooted in the traditional IS literature, this research proposes that TTF be extended to incorporate additional factors unique to the context of Knowledge Management (KM). Based upon the findings of this research, it is reasonable to conclude that when employing the TTF model to determine KMS fitness, additional factors other than the task requirements and KMS capabilities should be considered. This …
The Concept Design Of A Split Flow Liquid Hydrogen Turbopump, Michael A. Arguello
The Concept Design Of A Split Flow Liquid Hydrogen Turbopump, Michael A. Arguello
Theses and Dissertations
An initial design of a split flow liquid hydrogen turbopump for the Dual Expander Aerospike Nozzle (DEAN) upper stage engine was completed. The engine nozzle is an annular aerospike. The engine cycle requires a combustion chamber pressure of 1,740 psia. The DEAN is designed to deliver 57,200 lbf of thrust and 472 seconds of Isp. The turbopump design was completed using a meanline software tool. The design consists of a single piece rotor, with a two-stage pump and radial inflow turbine. The turbopump flow rates are 15.1 and 7.55 lbm/s into the first and second stage, respectively. The first and …
An Experimental Technique For Developing Intermediate Strain Rates In Ductile Metals, Hugh E. Gardenier Iv
An Experimental Technique For Developing Intermediate Strain Rates In Ductile Metals, Hugh E. Gardenier Iv
Theses and Dissertations
Quantifying the strain-rate sensitive dynamic properties of structural materials is an important area of research in the solid mechanics field. Property evaluation is typically accomplished using dynamic tests which involve rapid loading or impact of specimens. In these tests, inertial forces and wave propagation make it difficult to accurately record the material response to a loading condition at an equivalent location. Furthermore, these tests typically generate high strain rates (in excess of 103 s−1) and an experimental method for generating rates of strain in the intermediate strain rate regime which is relatively simple, low cost, and reliable …
Analysis Of Multi-Layered Materials Under High Velocity Impact Using Cth, Jason K. Lee
Analysis Of Multi-Layered Materials Under High Velocity Impact Using Cth, Jason K. Lee
Theses and Dissertations
Multi-layer armor containing ceramic and metallic layers has become more common in the past two decades. Typically, ceramics have high compressive strength which combined with their low density make them highly desirable for armor applications. This research effort numerically simulates high velocity impact of cylindrical projectiles on multi-layer metallic and ceramic targets of finite thickness. The impact of the projectile occurs normal to the surface of the target. The projectiles used are made of either S7 tool steel or tungsten. The targets consist of either rolled homogeneous armor, 4340 steel and boron carbide ceramic or rolled homogeneous armor and boron …
Discrete Counting Of Short Lived Isotopes With Low Background Detectors, David E. Mather
Discrete Counting Of Short Lived Isotopes With Low Background Detectors, David E. Mather
Theses and Dissertations
We consider radiation counting experiments used to measure quantities of materials that are short-lived with respect to the count durations. The HPS 13.31 statistical analysis seriously overestimates the uncertainty when the quantity and background are very low. We consider the case in which the objective is to quantify the number of atoms, n, that were present in a sample when it was drawn. Mathews and Gerts [JRNC, 2008] analyzed this case and developed formulas for the probability distribution of n, in order to develop experiment design processes that minimize the smallest detectable quantity of material, thus maximizing sensitivity for the …
Optimal Guidance Of A Relay Mav For Isr Support Beyond Line-Of-Sight, John H. Hansen
Optimal Guidance Of A Relay Mav For Isr Support Beyond Line-Of-Sight, John H. Hansen
Theses and Dissertations
This thesis developed guidance laws to optimally position a relay Micro-UAV (MAV) to provide an operator with real-time Intelligence, Surveillance, and Reconnaissance (ISR) by relaying communication and video signals when there is no line-of-sight between the operator at the base and the rover MAV performing the ISR mission. The ISR system consists of two MAVs, the Relay and the Rover, and a Base. The Relay strives to position itself to minimize the radio frequency (RF) power required for maintaining communications between the Rover and the Base, while the Rover performs the ISR mission, which may maximize the required RF power. …
Software Assurance Best Practices For Air Force Weapon And Information Technology Systems - Are We Bleeding?, Ryan A. Maxon
Software Assurance Best Practices For Air Force Weapon And Information Technology Systems - Are We Bleeding?, Ryan A. Maxon
Theses and Dissertations
In the corporate world, "bits mean money," and as the Department of Defense (DoD) becomes more and more reliant on net-centric warfare, bits mean national security. Software security threats are very real, as demonstrated by the constant barrage of Internet viruses, worms, Trojans, and hackers seeking to exploit the latest vulnerability. Most organizations focus their resources on reactive defenses such as firewalls, antivirus software, and encryption, however as demonstrated by the numerous attacks that are successful, those post facto measures are not enough to stop the bleeding. The DoD defines software assurance (SwA) as the "level of confidence that software …
Finite Element Simulation Methods For Dry Sliding Wear, Aaron J. Chmiel
Finite Element Simulation Methods For Dry Sliding Wear, Aaron J. Chmiel
Theses and Dissertations
The Holloman High Speed Test Track is a rocket sled track for testing at hypersonic velocities. However, there are customers that desire to test at even greater velocities. In order to achieve higher velocities there are several phenomena that must be overcome. One important phenomenon is wear of the shoe that holds the sled on the rail. This research is a look at the feasibility of using finite element analysis to predict the wear of the shoe during a test run down the track. Two methods are investigated, one is a macro-scale, incremental method utilizing traditional wear equations from Archard, …
Minimizing Secular J2 Perturbation Effects On Satellite Formations, Jonathan W. Wright
Minimizing Secular J2 Perturbation Effects On Satellite Formations, Jonathan W. Wright
Theses and Dissertations
The purpose of this thesis is to examine the secular effects of the J2 oblateness perturbation on close proximity satellites. The main objective is to analyze the deputy’s position and velocity with respect to the chief and adjust the initial conditions of the deputy in an attempt to minimize the secular effects of J2 perturbations. Previous work has provided a method of obtaining a closed form solution for J2 invariance with co-planar orbits. Therefore, this work will primarily consider deputy orbits that experience motion outside of the chief’s orbital plane. Upon determining the required initial conditions, the …
Demonstration Of A Strategy To Perform Two-Dimensional Diode Laser Tomography, Ryan N. Givens
Demonstration Of A Strategy To Perform Two-Dimensional Diode Laser Tomography, Ryan N. Givens
Theses and Dissertations
Demonstration of a strategy to perform two-dimensional diode laser tomography using a priori knowledge from symmetry arguments and computational fluid dynamic (CFD) calculations is presented for a flat flame burner. The strategy uses an optimization technique to determine flame diameter and location using a vector quantization approach. Next, the variance in a training set, produced from CFD calculations, is captured using principal components analysis. The information in the training set allows interpolation between beam paths resulting in temperature and density maps. Finally, the TDLAS temperature and density maps are shown to agree with traditional thermocouple measurements of the flat flame …
An Image Based Bidirectional Reflectivity Distribution Function Experiment, Michael T. Hagg
An Image Based Bidirectional Reflectivity Distribution Function Experiment, Michael T. Hagg
Theses and Dissertations
The temperature dependence of Bidirectional Reflectivity Distribution Functions (BRDFs) is not well documented. For the sake of time and customer demand, current measurements are taken at room temperature, but the reflectivity of a material changes as a function of temperature. The assumption is that this change is uniform, and as such, the BRDF will retain its relative angular shape but perhaps be scaled in magnitude as a function of temperature. When BRDFs are to be used at elevated temperatures, a scaling factor is then applied. In addition, BRDF as a function of rate of change of temperature has been identified …
Thermal Characterization Of A Hall Effect Thruster, Alex M. Bohnert
Thermal Characterization Of A Hall Effect Thruster, Alex M. Bohnert
Theses and Dissertations
The thermal characteristics of a Hall thruster directly influence thruster and spacecraft design. High temperatures affect the magnetic coil capabilities and cause higher insulator erosion rates, influencing both thruster performance and lifetime. The Hall thruster transfers heat through both radiation and conduction, and the spacecraft must handle this additional thermal energy. An infrared camera provides a non-intrusive method to analyze the thermal characteristics of an operational Hall thruster. This thesis contains the thermal analysis of a Busek Co. Inc. 200 W Hall thruster, using a FLIR ThermaCAM SC640 infrared camera. The Space Propulsion Analysis and System Simulator Laboratory at the …