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A Method Of Surrogate Model Construction Which Leverages Lower-Fidelity Information Using Space Mapping Techniques, Jason W. Thomas
A Method Of Surrogate Model Construction Which Leverages Lower-Fidelity Information Using Space Mapping Techniques, Jason W. Thomas
Theses and Dissertations
A new method of surrogate construction is developed and applied to a pair of computational tools used in the field of aircraft design. This new method involves the pairing of data sampled from the analytical model of interest with the execution of a similar analysis performed at a lower level of fidelity. This pairing is accomplished through the use of a space mapping technique, which is a process where the design space of a lower fidelity model is aligned a higher fidelity model. The intent of applying space mapping techniques to the field of surrogate construction is to leverage the …
Computer Vision Tracking Using Particle Filters For 3d Position Estimation, Kyle D. Kenerley
Computer Vision Tracking Using Particle Filters For 3d Position Estimation, Kyle D. Kenerley
Theses and Dissertations
This line of research seeks to increase knowledge of a tracked target using the particle filter, also known as Sequential Monte Carlo (SMC) methods. The target is tracked using vision based observations. These observations were simulated using both dual cameras and a single camera. If only a single camera tracks the target, depth cannot be determined directly and is considered an unobservable state. Filters can estimate this unobservable state using a dynamic model and data from the image. However the movement of the target is nonlinear which eliminated filters traditionally used to track motion such as the Kalman filter and …
Model Uncertainty And Test Of A Segmented Mirror Telescope, Luke C. Dras
Model Uncertainty And Test Of A Segmented Mirror Telescope, Luke C. Dras
Theses and Dissertations
The future of large aperture telescopes relies heavily on the development of segmented array designs. Today's monolithic mirror technology has reached a barrier, particularly for space-based telescopes. These large diameter, dense mirrors allow stable high-resolution imaging but are incompatible with optimized space launch. Segmented mirror telescopes are designed to balance lightweight with compact stowage. The structure necessary to support the flexible mirror array often combines isogrid geometry and complex actuation hardware. High-fidelity finite element models are commonly used to economically predict how the optics will perform under different environmental conditions. The research detailed herein integrates superelement partitioning and complexity simplifying …
Analysis Of Biological Weapon Spread Through A Transportation Network, Michael V. Macandrew
Analysis Of Biological Weapon Spread Through A Transportation Network, Michael V. Macandrew
Theses and Dissertations
Biological weapons are one of the top five threats identified by the Department of Defense in the United States. While most people commonly associate weapons of mass destruction only with atomic bombs, biological agents still have the ability to inflict mass casualties and panic. By strategically placing bioweapon detection units, known as BioWatch, in various airports, a disease spread could be detected and mitigated before country wide dispersal of the disease occurs. Key cities to invest this program are investigated through network analysis of flight itineraries with large volumes of traffic. In addition to analyzing an airport network, there is …
Airborne Wireless Communication Modeling And Analysis With Matlab, Matthew J. Vincie
Airborne Wireless Communication Modeling And Analysis With Matlab, Matthew J. Vincie
Theses and Dissertations
Over the past decade, there has been a dramatic increase in the use of unmanned aerial vehicles (UAV) for military, commercial, and private applications. Critical to maintaining control and a use for these systems is the development of wireless networking systems [1]. Computer simulation has increasingly become a key player in airborne networking developments though the accuracy and credibility of network simulations has become a topic of increasing scrutiny [2-5]. Much of the inaccuracies seen in simulation are due to inaccurate modeling of the physical layer of the communication system. This research develops a physical layer model that combines antenna …
Validation Of The Air Force Weather Agency Ensemble Prediction Systems, William B. Clements
Validation Of The Air Force Weather Agency Ensemble Prediction Systems, William B. Clements
Theses and Dissertations
Air Force Weather Agency's (AFWA) Ensemble Prediction Systems (EPS), Global Ensemble Prediction System (GEPS), 20km Mesoscale Ensemble Prediction System (MEPS20) and 4km Mesoscale Prediction System (MEPS4), were evaluated from April to October 2013 for 10 locations around the world to determine how accurately forecast probabilities for wind and precipitation thresholds and lightning occurrence match observed frequencies using Aerodrome Routine Meteorological Reports (METARs) and Aerodrome Special Meteorological Reports (SPECIs). Reliability diagrams were created for each forecast hour detailing the Brier skill score (BSS) to depict EPS performance compared to climatology for each site and score composition through reliability, resolution and uncertainty. …
Characterization And Mitigation Of Resistive Losses In A Large Area Laser Power Converter, Eli A. Garduno
Characterization And Mitigation Of Resistive Losses In A Large Area Laser Power Converter, Eli A. Garduno
Theses and Dissertations
GaAs Laser Power Converters (LPC) were simulated in 2D and 3D under 10 W/cm2 illumination of 810 nm light using Synopsys Sentaurus software revealing significant dependence of efficiency on grid metal finger spacings, S, and finger dimensions. Efficiency results were comparable to an experimental efficiency of 53.4% cited in the literature for an LPC under 43 W/cm2 of 810 nm laser light. 2D devices were simulated with S of 20 - 1000 µm revealing an efficiency drop, Δη, with increasing spacings. The efficiency drop was reduced from Δη of 39.43% at S = 740 µm to Δη of …
Sensitivity Of 96 And 120-Hour Numerical Model Tropical Cyclone Position Forecasts To Initial Position Errors, Coy C. Fischer
Sensitivity Of 96 And 120-Hour Numerical Model Tropical Cyclone Position Forecasts To Initial Position Errors, Coy C. Fischer
Theses and Dissertations
Global Forecast System (GFS) western Pacific tropical cyclone track forecasts from the 2011, 2012, and 2013 seasons (87 storms) were compared to Joint Typhoon Warning Center (JTWC) tropical cyclone best track data and warning bulletins in order to determine the sensitivity of 96 and 120-hour tropical cyclone position forecasts to initial position error. A tropical cyclone vortex tracker, which uses seven different model parameters to track storm centers, was implemented to determine model forecast positions. The differences between JTWC analysis positions and the model-derived vortex positions were analyzed at each forecast hour (00, 12, 24, 36, 48, 72, 96, and …
Nuclear Structure Of Rhenium-186 Revealed By Neutron-Capture Gamma Rays, Andrew G. Lerch
Nuclear Structure Of Rhenium-186 Revealed By Neutron-Capture Gamma Rays, Andrew G. Lerch
Theses and Dissertations
The total radiative thermal neutron-capture cross section of 185Re(n,gamma) was calculated from measurements of its gamma-ray spectrum following irradiation of a highly enriched 185Re target in the guided thermal-neutron beam at the Budapest Research Reactor. The cross section was obtained by first summing the experimentally measured partial gamma ray-production cross sections associated with the known ground-state transitions below 323 keV. Combined with the contribution to ground-state population from the quasi-continuum, which was generated by the DICEBOX statistical-decay code, the resulting thermal neutron-capture cross section was determined to be 84(6) b. This result is statistically comparable to previous works. Additionally, 12 …
Electrical Characterization Of Spherical Copper Oxide Memristive Array Sensors, James P. Orta
Electrical Characterization Of Spherical Copper Oxide Memristive Array Sensors, James P. Orta
Theses and Dissertations
A new System Protection (SP) technology is explored by using electrical and mechanical interference-sensing devices that are implemented with granular memristive material. The granular materials consist of oxide-coated copper spheres with radii of about 700 µm that are placed in contact to produce thin oxide junctions which exhibit memristive behavior. Processes for etching, which compared acetic acid and nitric acid etches, and thermal oxidation at 100°C are performed and compared to produce copper spheres with a copper oxide layer over the sphere surface. Oxidized copper spheres are tested as sensor arrays by loading into a capillary tube in an aligned …
Positron Spectroscopy Of Hydrothermally Grown Actinide Oxides, Edward C. Schneider
Positron Spectroscopy Of Hydrothermally Grown Actinide Oxides, Edward C. Schneider
Theses and Dissertations
In recent years AFIT has built expertise and resources dedicated to the growth and characterization of actinide oxides. The primary purpose of this research was to integrate positron spectroscopy ? with which AFIT also has a long history ? into this actinide research. The main objectives were to construct a Positron Annihilation Lifetime Spectroscopy system, including a new positron source, and to characterize a number of hydrothermally grown ThO2 and U:ThO2 crystals. Lifetime measurements were conducted on nine crystal samples and the spectra analyzed to determine the purity and quality of the crystals. In addition, analysis and fitting of the …
Reconstruction Error And Principal Component Based Anomaly Detection In Hyperspectral Imagery, James A. Jablonski
Reconstruction Error And Principal Component Based Anomaly Detection In Hyperspectral Imagery, James A. Jablonski
Theses and Dissertations
The rapid expansion of remote sensing and information collection capabilities demands methods to highlight interesting or anomalous patterns within an overabundance of data. This research addresses this issue for hyperspectral imagery (HSI). Two new reconstruction based HSI anomaly detectors are outlined: one using principal component analysis (PCA), and the other a form of non-linear PCA called logistic principal component analysis. Two very effective, yet relatively simple, modifications to the autonomous global anomaly detector are also presented, improving algorithm performance and enabling receiver operating characteristic analysis. A novel technique for HSI anomaly detection dubbed multiple PCA is introduced and found to …
Optimizing Air Force Depot Programming To Maximize Operational Capability, James D. Rhoads
Optimizing Air Force Depot Programming To Maximize Operational Capability, James D. Rhoads
Theses and Dissertations
The Air Force wants to improve the link between resources and weapons system readiness by reducing costs, improving risk-based decision making, and balancing costs with performance. With that in mind, RAND Project Air Force developed a linear programming model linking Depot Purchased Equipment Maintenance to operational capability. This thesis examined that model, provided an alternate model, and then developed a new model that determined the minimum cost necessary to maintain the force structure. The utility of using the models using Weapon System Sustainment (WSS) and additional sources of data for aircraft and engine inventories was evaluated and critiqued. While every …
A Methodology For Measuring Resilience In A Satellite-Based Communication Network, Jonathan S. Turner
A Methodology For Measuring Resilience In A Satellite-Based Communication Network, Jonathan S. Turner
Theses and Dissertations
According to Presidential Policy Directive 21, increasing resilience of critical infrastructures is not only desired, but United States policy. Communications infrastructures are one such critical infrastructure. The purpose of this research is to develop a methodology for measuring resilience in satellite communication systems for use as a key criterion in the selection and acquisition of new satellite architectures, in accordance with the National Security Space Strategy. The base methodology utilized in this thesis is Extreme Event Modeling implemented through the use of Bi-Level Programming with monotonically nonlinear continuous and mixed integer variables. This model differs from previous efforts applied to …
Strategic Positioning Of United States Air Force Civil Engineer Contingency Equipment Within The Supply Chain, Scott D. Adamson
Strategic Positioning Of United States Air Force Civil Engineer Contingency Equipment Within The Supply Chain, Scott D. Adamson
Theses and Dissertations
The consolidation and forward positioning of critical inventories often provides substantial benefits over a geographically dispersed posture. Such benefits include, but are not limited to: increased inventory visibility, reduced transportation costs, and fewer manpower requirements. Presently, the United States Air Force (USAF) Civil Engineer (CE) community maintains a disseminated posture of equipment Unit Type Codes (UTCs), which regularly experiences inconsistencies in handling, tracking, and capability reporting. Provided the aforementioned discrepancies, this research effort examines several aspects surrounding the decision to potentially centralize critical CE inventories to either one or two locations. Specifically, the areas of cost, risk, and manpower are …
A Survey And Analysis Of Aircraft Maintenance Metrics: A Balanced Scorecard Approach, Adrienne L. Stahl
A Survey And Analysis Of Aircraft Maintenance Metrics: A Balanced Scorecard Approach, Adrienne L. Stahl
Theses and Dissertations
Performance metrics have helped to sustain the Air Force, improve processes, and guided decisions makers through decades of challenges and change. The Air Force continues to change as it faces the challenges of an aging fleet coupled with the tightest budget constraints of modern times. The current metrics employed by the United States Air Force Aircraft Maintenance community have gone largely unchanged over decades despite a host of force altering events. The focus of this research is to evaluate current maintenance metrics and assess the utility of the Balanced Scorecard framework for use in a Maintenance Group. The researcher utilizes …
A Change Management Approach To Enhance Facility Maintenance Programs, Stanton P. Brown
A Change Management Approach To Enhance Facility Maintenance Programs, Stanton P. Brown
Theses and Dissertations
A recent study assigned a grade of D+ on the nation's public infrastructure. Because of this poor asset condition, many organizations tend to respond to maintenance in a reactive mode; however, relying on corrective maintenance leads to increased maintenance costs due to unplanned downtime, increased labor costs, and inefficient use of personnel. To address this situation, asset management (AM) principles should be employed to transition organizations towards a proactive maintenance program. Unfortunately, it has been shown that two-thirds of the organizations failed to implement general change efforts. Therefore, an organizational change management framework should be followed to implement a change …
A Macro-Stochastic Approach To Improved Cost Estimation For Defense Acquisition Programs, Allen J. Deneve
A Macro-Stochastic Approach To Improved Cost Estimation For Defense Acquisition Programs, Allen J. Deneve
Theses and Dissertations
Space is becoming increasingly congested as more objects are launched into orbit. The potential for a collision on orbit increases each time a new object enters space. This thesis presents a methodology to determine an optimal direction to maneuver a satellite that may be involved in a potential collision. The author presents a paradigm to determine the optimal direction of maneuver to achieve the lowest probability of collision, and examines how different magnitudes of a maneuver will affect the probability of collision. The methodology shows that if a satellite maneuvers in the optimal direction at any time during the orbit, …
Cloud Computing Implementation Organizational Success In The Department Of Defense, Corey J. Perkins
Cloud Computing Implementation Organizational Success In The Department Of Defense, Corey J. Perkins
Theses and Dissertations
The DoD tends to implement user based IT systems without quantifying whether those systems would be properly utilized by the target populous. Focus is generally emphasized on mission enhancement rather than looking at how or if it will be utilized by organizations. There would appear to be no reason for cloud computing to be implemented with the same disregard for acceptance and success. The day of large amounts of data is here and needs to converge with what this thesis investigates, the factors that positively influence organization acceptance and success of cloud computing specifically in the DoD so that is …
Modeling The Effects Of Ultraviolet (Uv) Light Emitting Diode (Led) Use In The Advanced Oxidation Process (Aop), John P. Richwine
Modeling The Effects Of Ultraviolet (Uv) Light Emitting Diode (Led) Use In The Advanced Oxidation Process (Aop), John P. Richwine
Theses and Dissertations
The United States Environmental Protection Agency (EPA) is concerned with both accidental and intentional releases of chemicals into waste streams. Certain chemicals may be detrimental to the effectiveness of municipal wastewater treatment plants. This can lead to reduced capability or costly damage to the plant. An Advanced Oxidation Process (AOP) is one method to pre-treat waste streams. This method uses ultraviolet (UV) energy and hydrogen peroxide to create hydroxyl radicals that can neutralize harmful chemicals. Recent advancements in Ultra Violet Light Emitting Diodes (UV LEDs) are making it possible to use this energy source instead of traditional UV energy sources. …
Thermal And Melt Wear Characterization Of Materials In Sliding Contact At High Speed Energy Sink, Christopher J. Alban
Thermal And Melt Wear Characterization Of Materials In Sliding Contact At High Speed Energy Sink, Christopher J. Alban
Theses and Dissertations
The Holloman High Speed Test Track is used to evaluate hypersonic aircraft materiel in a near-operational environment. The four-stage pusher rocket sled is capable of accelerating a test apparatus to hypersonic speeds in a matter of seconds. The sled must contend with tremendous thermal, mechanical, and aerodynamic loading during each run. The effects of the combination of forces acting on the sled are most acute at the interface between the rail and the wraparound slipper that holds the sled to the rail. Frictional heating due to sliding contact between the slipper and the rail coupled with mechanical wear can lead …
Feasibilty Of Very Large Sparse Aperture Depolyable Antennas, Jason C. Heller
Feasibilty Of Very Large Sparse Aperture Depolyable Antennas, Jason C. Heller
Theses and Dissertations
The objective of this research is to explore the technical soundness of a very large, cross-shaped, parabolic, sparse aperture antenna extending 75 m from the bus. Specifically, describing the environment of the satellite, the effect of fabrication error on the structure and the remaining error budget for the system. The methodology involves creation of an ideal truss structure, to which all others are compared. A uniform distribution of proportional errors up to 1e-5 is introduced into the truss members' lengths and the models are subjected to a static Finite Element Analysis. A solution for the surface normal error is addressed …
Bayesian Methods And Confidence Intervals For Automatic Target Recognition Of Sar Canonical Shapes, Richard W. Rademacher
Bayesian Methods And Confidence Intervals For Automatic Target Recognition Of Sar Canonical Shapes, Richard W. Rademacher
Theses and Dissertations
This research develops a new Bayesian technique for the detection of scattering primitives in synthetic aperture radar (SAR) phase history data received from a sensor platform. The primary goal of this research is the estimation of size, position, and orientation parameters defined by the “canonical” shape primitives of Jackson. Previous Bayesian methods for this problem have focused on the traditional maximum a posteriori (MAP) estimate based on the posterior density. A new concept, the probability mass interval, is developed. In this technique the posterior density is partitioned into intervals, which are then integrated to form a probability mass over that …
Feature Selection On Hyperspectral Data For Dismount Skin Analysis, Lindsay R. Cain
Feature Selection On Hyperspectral Data For Dismount Skin Analysis, Lindsay R. Cain
Theses and Dissertations
Many security applications require the ability to accurately identify dismounts based on their distinctive identification properties. A dismount can be identified by many personal characteristics to include clothing, height, and gait. In particular, a dismount's skin can be used as an identifying feature because of the vast variability of skin pigmentation amongst individuals. Hyperspectral data, which is comprised of hundreds of spectral channels sampled from a nearly contiguous electromagnetic spectrum, is used to detect skin spectral variability amongst dismounts. However, hyperspectral data is often highly correlated and computationally expensive to process. Feature selection methods can be employed to reduce the …
Numerical Integration With Graphical Processing Unit For Qkd Simulation, Virginia R. Garrett
Numerical Integration With Graphical Processing Unit For Qkd Simulation, Virginia R. Garrett
Theses and Dissertations
The Air Force Institute of Techology (AFIT) is developing a simulation framework to model a wide variety of existing and proposed Quantum Key Distribution (QKD) systems. This research investigates using graphical processing unit (GPU) technology to more efficiently integrate optical pulses modeled within this framework. The goal is to reduce the simulation execution time. A GPU algorithm is presented for performing numerical integration of optical pulses described by Gaussian curves to improve pulse energy and power calculations. In order to measure the performance of the algorithm a optimal timing method is needed. A timer using Comute Unified Device Architecture (CUDA) …
Identifying High-Traffic Patterns In The Workplace With Radio Tomographic Imaging In 3d Wireless Sensor Networks, Thea S. Danella
Identifying High-Traffic Patterns In The Workplace With Radio Tomographic Imaging In 3d Wireless Sensor Networks, Thea S. Danella
Theses and Dissertations
The rapid progress of wireless communication and embedded mircro-sensing electro-mechanical systems (MEMS) technologies has resulted in a growing confidence in the use of wireless sensor networks (WSNs) comprised of low-cost, low-power devices performing various monitoring tasks. Radio Tomographic Imaging (RTI) is a technology for localizing, tracking, and imaging device-free objects in a WSN using the change in received signal strength (RSS) of the radio links the object is obstructing. This thesis employs an experimental indoor three-dimensional (3-D) RTI network constructed of 80 wireless radios in a 100 square foot area. Experimental results are presented from a series of stationary target …
A Recommender System In The Cyber Defense Domain, Katherine B. Lyons
A Recommender System In The Cyber Defense Domain, Katherine B. Lyons
Theses and Dissertations
In the cyber domain, network defenders have traditionally been placed in a reactionary role. Before a defender can act they must wait for an attack to occur and identify the attack. This places the defender at a disadvantage in a cyber attack situation and it is certainly desirable that the defender out maneuver the attacker before the network has been compromised. The goal of this research is to determine the value of employing a recommender system as an attack predictor, and determine the best configuration of a recommender system for the cyber defense domain. The most important contribution of this …
Vulnerability Analysis Of The Mavlink Protocol For Command And Control Of Unmanned Aircraft, Joseph A. Marty
Vulnerability Analysis Of The Mavlink Protocol For Command And Control Of Unmanned Aircraft, Joseph A. Marty
Theses and Dissertations
The MAVLink protocol is an open source, point-to-point networking protocol used to carry telemetry and to command and control many small unmanned aircraft. This research presents three exploits that compromise confidentiality, integrity, and availability vulnerabilities in the communication between an unmanned aerial vehicle and a ground control station using the MAVLink protocol. The attacks assume the configuration settings for the data-link hardware have been obtained. Field experiments using MAVProxy to compromise communication between an ArduPilot Mega 2.5 autopilot and the Mission Planner application demonstrate that all three exploits are successful when MAVLink messages are unprotected. A methodology is proposed to …
Outperforming Game Theoretic Play With Opponent Modeling In Two Player Dominoes, Michael M. Myers
Outperforming Game Theoretic Play With Opponent Modeling In Two Player Dominoes, Michael M. Myers
Theses and Dissertations
Dominoes is a partially observable extensive form game with probability. The rules are simple; however, complexity and uncertainty of this game make it difficult to apply standard game theoretic methods to solve. This thesis applies strategy prediction opponent modeling to work with game theoretic search algorithms in the game of two player dominoes. This research also applies methods to compute the upper bound potential that predicting a strategy can provide towards specific strategy types. Furthermore, the actual values are computed according to the accuracy of a trained classifier. Empirical results show that there is a potential value gain over a …
Redir: Automated Static Detection Of Obfuscated Anti-Debugging Techniques, Adam J. Smith
Redir: Automated Static Detection Of Obfuscated Anti-Debugging Techniques, Adam J. Smith
Theses and Dissertations
Reverse Code Engineering (RCE) to detect anti-debugging techniques in software is a very difficult task. Code obfuscation is an anti-debugging technique makes detection even more challenging. The Rule Engine Detection by Intermediate Representation (REDIR) system for automated static detection of obfuscated anti-debugging techniques is a prototype designed to help the RCE analyst improve performance through this tedious task. Three tenets form the REDIR foundation. First, Intermediate Representation (IR) improves the analyzability of binary programs by reducing a large instruction set down to a handful of semantically equivalent statements. Next, an Expert System (ES) rule-engine searches the IR and initiates a …