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Air Force Institute of Technology

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Articles 1321 - 1350 of 2678

Full-Text Articles in Physical Sciences and Mathematics

The Economic Impact Of A Radiological Dispersal Device (Rde), Michael T. Lebrun Mar 2009

The Economic Impact Of A Radiological Dispersal Device (Rde), Michael T. Lebrun

Theses and Dissertations

While it will not cause the devastation of a nuclear weapon, the radiological dispersal event (RDE) is particularly dangerous in that it has the potential to cause major economic disruptions. The purpose of this research was to develop a generalized methodology that can be used to assess economic impacts, resulting from a (RDE), occurring in any location and across any industry. Currently, there is no universal approach for measuring the costs or economic impacts on businesses, or a common framework for conducting an economic impact for a RDE. The objective of this research was to aid in the RDE response …

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An Evaluation Of Solar Air Heating At United States Air Force Installations, David S. Brown Mar 2009

An Evaluation Of Solar Air Heating At United States Air Force Installations, David S. Brown

Theses and Dissertations

The purpose of this research was to evaluate the use of solar air heating at U.S. Air Force installations. Specifically, this thesis analyzed Unglazed Transpired Collector (UTC) technology, more commonly known as SolarWalls®. This thesis sought to determine if UTC systems are an economically and environmentally viable technology which Air Force energy managers should include in their portfolio of alternative energy options. This research question was answered through the use of case studies and life-cycle cost analysis. Case studies were performed at various U.S. military installations which have already utilized UTC systems to provide a consolidated source of lessons learned. …

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A Taxonomy For And Analysis Of Anonymous Communications Networks, Douglas J. Kelly Mar 2009

A Taxonomy For And Analysis Of Anonymous Communications Networks, Douglas J. Kelly

Theses and Dissertations

Any entity operating in cyberspace is susceptible to debilitating attacks. With cyber attacks intended to gather intelligence and disrupt communications rapidly replacing the threat of conventional and nuclear attacks, a new age of warfare is at hand. In 2003, the United States acknowledged that the speed and anonymity of cyber attacks makes distinguishing among the actions of terrorists, criminals, and nation states difficult. Even President Obama’s Cybersecurity Chief-elect recognizes the challenge of increasingly sophisticated cyber attacks. Now through April 2009, the White House is reviewing federal cyber initiatives to protect US citizen privacy rights. Indeed, the rising quantity and ubiquity …

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Range Estimation Algorithm Comparison In 3-D Flash Ladar Data, Steven P. Jordan Mar 2009

Range Estimation Algorithm Comparison In 3-D Flash Ladar Data, Steven P. Jordan

Theses and Dissertations

Range estimation algorithms have been applied to Laser Detection and Ranging (LADAR) data to test for accuracy and precision. Data was acquired from Matlab® simulations and an experiment using the Advanced Scientific Concepts 3-D flash LADAR camera. Simulated LADAR data was based on a Gaussian pulse shape model with Poisson noise added. Simulations were performed to test range estimation algorithm performance with respect to waveform position within the range gate. The effectiveness of each algorithm is presented in terms of its average root mean square error and standard deviation in 1000 trials. The measured data experiment examined the effectiveness of …

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Blind Deconvolution Through Polarization Diversity Of Long Exposure Imagery, Steven P. James Mar 2009

Blind Deconvolution Through Polarization Diversity Of Long Exposure Imagery, Steven P. James

Theses and Dissertations

The purpose of the algorithm developed in this thesis was to create a post processing method that could resolve objects at low signal levels using polarization diversity and no knowledge of the atmospheric seeing conditions. The process uses a two-channel system, one unpolarized image and one linearly polarized image, in a GEM algorithm to reconstruct the object. Previous work done by Strong showed that a two-channel system using polarization diversity on short exposure imagery could produce images up to twice the diffraction limit. In this research, long exposure images were simulated and a simple Kolmogorov model used. This allowed for …

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Modeling Of Aircraft Deicing Fluid Induced Biochemical Oxygen Demand In Subsurface-Flow Constructed Treatment Wetlands, William J. Mclaughlin Mar 2009

Modeling Of Aircraft Deicing Fluid Induced Biochemical Oxygen Demand In Subsurface-Flow Constructed Treatment Wetlands, William J. Mclaughlin

Theses and Dissertations

Aircraft deicing is vital to safe operation in cold weather environments. Unfortunately, release of glycol-based aircraft deicing fluids (ADF) to waterways adjacent to airfields poses a significant environmental threat. The deicing fluids used at DoD airfields impart a high biochemical oxygen demand (BOD) when they enter waterways. The currently accepted conventional treatment is collection and transport of ADF-laden storm water to a publicly owned treatment works. The volume and BOD concentrations in the storm water often make this type of treatment impractical. Subsurface flow constructed treatment wetlands have been demonstrated to be effective in attenuating ADF-induced BOD. The models currently …

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Mitigating Insider Sabotage And Espionage: A Review Of The United States Air Force's Current Posture, Erika C. Leach Mar 2009

Mitigating Insider Sabotage And Espionage: A Review Of The United States Air Force's Current Posture, Erika C. Leach

Theses and Dissertations

The security threat from malicious insiders affects all organizations. Mitigating this problem is quite difficult due to the fact that (1) there is no definitive profile for malicious insiders, (2) organizations have placed trust in these individuals, and (3) insiders have a vast knowledge of their organization’s personnel, security policies, and information systems. The purpose of this research is to analyze to what extent the United States Air Force (USAF) security policies address the insider threat problem. The policies are reviewed in terms of how well they align with best practices published by the Carnegie Mellon University Computer Emergency Readiness …

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Operations-Focused Optimized Theater Weather Sensing Strategies Using Preemptive Binary Integer Programming, Andrew J. Geyer Mar 2009

Operations-Focused Optimized Theater Weather Sensing Strategies Using Preemptive Binary Integer Programming, Andrew J. Geyer

Theses and Dissertations

This thesis describes a method that optimally deploys weather sensors of all types in a battlefield environment. Gridded climatology models are used to determine an estimate for the weighted frequency of occurrence of operationally significant inclement weather events. That data is used to formulate a series of preemptive Binary Integer Linear Programs that maximize detection of expected operationally significant inclement weather occurrences within the constraints of feasibility of sensor deployment, sensor operational lifespan and the sensor’s ability to detect the operationally significant inclement weather elements. The preemptive Binary Integer Linear Programs are combined into a single objective function that maintains …

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Detecting Near-Earth Objects Using Cross-Correlation With A Point Spread Function, Anthony P. O'Dell Mar 2009

Detecting Near-Earth Objects Using Cross-Correlation With A Point Spread Function, Anthony P. O'Dell

Theses and Dissertations

This thesis describes a process to help discover Near-Earth Objects (NEOs) of larger than 140 meters in diameter from ground based telescopes. The process involves using Nyquist sampling rate to take data from a ground-based telescope and measuring the atmospheric seeing parameter, r0, at the time of data collection. r0 is then used to create a point spread function (PSF) for a NEO at the visual magnitude limit of the telescope and exposure time. This PSF is cross-correlated with the Nyquist sampling rate image from the telescope to reduce the noise and therefore increase the detection probability of …

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Evaluation Of An Innovative Technology For Treatment Of Water Contaminated With Perchlorate And Organic Compunds, Maureen A. Downen Mar 2009

Evaluation Of An Innovative Technology For Treatment Of Water Contaminated With Perchlorate And Organic Compunds, Maureen A. Downen

Theses and Dissertations

Drinking water sources contaminated with both perchlorate and organic compounds have frequently been found in the U.S. Tailored granular activated carbon (T-GAC) is an innovative technology that is being evaluated to determine if it can more cost effectively remove perchlorate than conventional technologies. A question that has been raised is whether T-GAC can economically treat perchlorate-contaminated water that also has organic co-contaminants present. During a field study, trichloroethylene, an organic compound, and perchlorate were successfully removed by adsorption using a T-GAC/GAC system. These results motivated development of a model that could be applied to predict the cost and performance of …

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Using Covert Means To Establish Cybercraft Command And Control, Bradley D. Sevy Mar 2009

Using Covert Means To Establish Cybercraft Command And Control, Bradley D. Sevy

Theses and Dissertations

With the increase in speed and availability of computers, our nation's computer and information systems are being attacked with increased sophistication. The Air Force Research Laboratory (AFRL) Information Directorate (RI) is researching a next generation network defense architecture, called Cybercraft, that provides automated and trusted cyber defense capabilities for AF network assets. This research we consider the issues to protect or obfuscate command and control aspects of Cybercraft. In particular, we present a methodology to hide aspects of Cybercraft platform initialization in context to formation of hierarchical, peer-to-peer groups that collectively form the Cybercraft network. Because malicious code networks (known …

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Jet Fuel Hedging Strategies For The Department Of Defense Through Use Of Financial Derivatives, William T. Gibson Mar 2009

Jet Fuel Hedging Strategies For The Department Of Defense Through Use Of Financial Derivatives, William T. Gibson

Theses and Dissertations

The primary purpose of this research is to assess the practicality of utilizing some of the financial derivative products available on the market today in an effort to mitigate monetary losses due to the increasing price of jet fuel, thereby increasing stability in the DOD budget. The scope of this research will focus on the use of futures and call option contracts. Domestic jet fuel expenditure data was collected for Fiscal Years 1996 to 2007 and cross-referenced with the contract process of the previously mentioned financial hedging instruments during the same period of time. Results from the ex post facto …

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Cooperative Unmanned Aerial Surveillance Control System Architecture, Theodore T. Diamond, Adam L. Rutherford, Jonathan B. Taylor Mar 2009

Cooperative Unmanned Aerial Surveillance Control System Architecture, Theodore T. Diamond, Adam L. Rutherford, Jonathan B. Taylor

Theses and Dissertations

Intelligence, surveillance and reconnaissance (ISR) is a high-demand Department of Defense mission performed by unmanned aircraft systems (UASs) at the tactical and theater levels. Coordinating UASs through cooperative control offers the advantages of persistence, distributed and adaptable sensor coverage, and reduced revisit time on points of interest. The purpose of this thesis is to apply systems engineering principles to the problem of developing a flexible, common control system for cooperative UAS surveillance at the tactical level. The AFIT team developed a concept of operations (CONOPS) encompassing various users and surveillance tasks. The team then used the scenarios in the CONOPS …

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Waypoint Generation Based On Sensor Aimpoint, Shannon M. Farrell Mar 2009

Waypoint Generation Based On Sensor Aimpoint, Shannon M. Farrell

Theses and Dissertations

Secretary of Defense Robert M. Gates has emphasized a need for a greater number of intelligence, surveillance, and reconnaissance (ISR) assets to support combatant commanders and military operations globally. Unmanned systems, especially MAVs, used as ISR platforms provide the ability to maintain covertness during missions and help reduce the risk to human life. This research develops waypoint generation algorithms required to keep a point of interest (POI) in the field of view (FOV) of a fixed sensor on a micro air vehicle (MAV) in the presence of a constant wind.
Fixed sensors, while cheaper and less prone to mechanical failure …

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Using Agent-Based Modeling To Evaluate Uas Behaviors In A Target-Rich Environment, Joseph A. Van Kuiken Mar 2009

Using Agent-Based Modeling To Evaluate Uas Behaviors In A Target-Rich Environment, Joseph A. Van Kuiken

Theses and Dissertations

The trade-off between accuracy and speed is a re-occurring dilemma in many facets of military performance evaluation. This is an especially important issue in the world of ISR. One of the most progressive areas of ISR capabilities has been the utilization of Unmanned Aircraft Systems (UAS). Many people believe that the future of UAS lies in smaller vehicles flying in swarms. We use the agent-based System Effectiveness and Analysis Simulation (SEAS) to create a simulation environment where different configurations of UAS vehicles can process targets and provide output that allows us to gain insight into the benefits and drawbacks of …

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A Comparative Study Of The Bidirectional Reflectance Distribution Function Of Several Surfaces As A Mid-Wave Infrared Diffuse Reflectance Standard, Bradley Balling Mar 2009

A Comparative Study Of The Bidirectional Reflectance Distribution Function Of Several Surfaces As A Mid-Wave Infrared Diffuse Reflectance Standard, Bradley Balling

Theses and Dissertations

The Bi-Directional Reflectance Distribution Function (BRDF) has a well defined diffuse measurement standard in the ultraviolet, visible, and near infrared (NIR), Spectralon(trade name). It is predictable, stable, repeatable, and has low surface variation because it is a bulk scatterer. In the mid-wave IR (MWIR) and long-wave IR (LWIR), there is not such a well-defined standard. There are well-defined directional hemispherical reflectance (DHR) standards, but the process of integrating BRDF measurements into DHR for the purpose of calibration is problematic, at best. Direct BRDF measurement standards are needed. This study use current calibration techniques to ensure valid measurements and then systematically …

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Misregistration In Adaptive Optics Systems, Nathan D. Engstrom Mar 2009

Misregistration In Adaptive Optics Systems, Nathan D. Engstrom

Theses and Dissertations

An adaptive optics (AO) system is most effective when there is a known alignment between the wave front sensor (WFS) and the deformable mirror (DM). Misregistration is the term for the unknown alignment between the WFS and DM. Misregistration degrades system performance and can make the system unstable. An AO system uses a reconstruction matrix to transform WFS measurements into DM commands. A standard AO system uses a model reconstruction matrix that assumes perfect registration between the WFS and DM. The object of this research is to mitigate the negative effects of misregistration by using offline WFS measurements to create …

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Hyperspectral Imaging Of A Turbine Engine Exhaust Plume To Determine Radiance, Temperature, And Concentration Spatial Distributions, Spencer J. Bowen Mar 2009

Hyperspectral Imaging Of A Turbine Engine Exhaust Plume To Determine Radiance, Temperature, And Concentration Spatial Distributions, Spencer J. Bowen

Theses and Dissertations

The usefulness of imaging Fourier transform spectroscopy (IFTS) when looking at a rapidly varying turbine engine exhaust scene was explored by characterizing the scene change artifacts (SCAs) present in the plume and the effect they have on the calibrated spectra using the Telops, Inc.-manufactured Field-portable Imaging Radiometric Spectrometer Technology, Midwave Extended (FIRST-MWE). It was determined that IFTS technology can be applied to the problem of a rapidly varying turbine engine exhaust plume due to the zero mean, stochastic nature of the SCAs, through the use of temporal averaging. The FIRST-MWE produced radiometrically calibrated hyperspectral datacubes, with calibration uncertainty of 35% …

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Q-Switched And Mode Locked Short Pulses From A Diode Pumped, Yb-Doped Fiber Laser, Seth M. Swift Mar 2009

Q-Switched And Mode Locked Short Pulses From A Diode Pumped, Yb-Doped Fiber Laser, Seth M. Swift

Theses and Dissertations

A diode-pumped, ytterbium (Yb)-doped fiber laser system was designed and demonstrated to operate in continuous wave (cw), passively Q-switched and possibly passively mode locked operation. To our knowledge, this was the first fiber laser oscillator built at the Air Force Institute of Technology. A Cr4+:YAG (Chromium: Ytterbium Aluminum Garnett) crystal was used as a saturable absorber to generate Q-switched pulses. Attempts to mode lock the laser were performed using a semiconductor saturable absorber mirror (SESAM) and through nonlinear polarization rotation (NPR). The best output power result was 5 Watts (W) while pumping at 8.3 W, yielding 60% efficiency …

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In Vitro Toxicity Of Silver Nanoparticles In Human Lung Epithelial Cells, Christina R. Kearns Mar 2009

In Vitro Toxicity Of Silver Nanoparticles In Human Lung Epithelial Cells, Christina R. Kearns

Theses and Dissertations

Nanotechnology is quickly becoming incorporated into everyday products and uses. Silver nanoparticles, specifically, are being used in commercial products, to include aerosols. The purpose of this research was to determine whether silver nanoparticles are toxic to human lung epithelial cells. Different types (coated vs. uncoated), concentrations (10, 50, 100, and 200 µg/mL) and sizes (coated 5 and 80nm, uncoated 10 and 80nm) of silver nanoparticles were used during this study. Toxicity measurements were completed through in vitro techniques. Another study was also completed on toxicity mechanisms by measuring the reactive oxygen species (ROS) generated. Results showed that silver nanoparticles induce …

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The Development Of It Suspicion As A Construct And Subsequent Measure, Matthew T. Olson Mar 2009

The Development Of It Suspicion As A Construct And Subsequent Measure, Matthew T. Olson

Theses and Dissertations

Suspicion has not been studied in great depth; however, a conceptual understanding of suspicion is no less important than many of the other highly studied constructs related to healthy working relationships. Information technology (IT) is one area where suspicion study is lacking, and this research effort was a study into the specific domain of IT suspicion. An extensive study of the suspicion literature and the suspicion nomological net as well as informal surveys of the general populous and subject matter experts were used to create an IT suspicion conceptual definition and measure. In order to test IT suspicion’s relationships with …

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Probabilistic Estimation Of Rare Random Collisions In 3-Space, Timothy Holzmann Mar 2009

Probabilistic Estimation Of Rare Random Collisions In 3-Space, Timothy Holzmann

Theses and Dissertations

A study of risk assessment for artillery fire randomly colliding with fixed wing aircraft is presented. The research lends itself to a general study of collision models. Current models of object collisions fall under one of three categories: the historical model, the gas particle model, and the satellite model. These three vary in data requirements and mathematical representation of the impact event. The gas particle model is selected for its flexibility and robust estimation. However, current mathematical development in the literature does not include certain spatial and dynamic components necessary for a general encounter (collision) model. These are derived in …

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Assessment Of Weather Sensitivities And Air Force Weather (Afw) Support To Tactical Lasers In The Lower Troposphere, Francesco J. Echeverria Mar 2009

Assessment Of Weather Sensitivities And Air Force Weather (Afw) Support To Tactical Lasers In The Lower Troposphere, Francesco J. Echeverria

Theses and Dissertations

ATL scientists need to develop a full understanding of the interaction effects between a high-energy laser beam and the atmosphere through which it propagates. Achieving this understanding is important for many reasons. In particular, the high cost of DE weapons systems makes each propagation event expensive. Having an understanding of the atmosphere in which a high-energy laser propagates will increase efficiency and effectiveness of the ATL weapon system, which in turn will decrease cost of operation. A tool that allows for the ATL war-fighter to determine the atmospheric effects on laser propagation currently does not exist. This study creates a …

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A Wigner Distribution Analysis Of One Dimensional Scattering, Brent R. Lacy Mar 2009

A Wigner Distribution Analysis Of One Dimensional Scattering, Brent R. Lacy

Theses and Dissertations

We applied the Wigner Distribution Function, a distribution function of time and frequency based on an initial function of either of those variables, to a series of time based correlation functions. These time based correlation functions were the result of a 1-dimensional free particle wave packet, the reactant wave function, which had propagated through a quantum potential well and then had components of the reactant wave function that exited the opposite side of the well auto-correlated in time with a stationary 1-dimensional free particle wave packet, the product wave function. This process was undertaking in order to generate a 3-dimensional …

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A Computational Tool For Evaluating Thz Imaging Performance In Brownout Conditions At Land Sites Throughout The World, Seth L. Marek Mar 2009

A Computational Tool For Evaluating Thz Imaging Performance In Brownout Conditions At Land Sites Throughout The World, Seth L. Marek

Theses and Dissertations

This study quantifies terahertz (THz) or sub-millimeter imaging performance during simulated rotary-wing brownout or whiteout environments based on geographic location and recent/current atmospheric weather conditions. The atmospheric conditions are defined through the Air Force Institute of Technology Center for Directed Energy (AFIT/CDE) Laser Environmental Effects Definition and Reference or LEEDR model. This model enables the creation of vertical profiles of temperature, pressure, water vapor content, optical turbulence, and atmospheric particulates and hydrometeors as they relate to line-by-line layer extinction coefficient magnitude at wavelengths from the UV to the RF. Optical properties and realistic particle size distributions for the brownout and …

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Electron Multipactor: Theory Review, Comparison And Modeling Of Mitigation Techniques In Icepic, Neil G. Rogers Mar 2009

Electron Multipactor: Theory Review, Comparison And Modeling Of Mitigation Techniques In Icepic, Neil G. Rogers

Theses and Dissertations

Mitigation approaches for single surface multipactor at dielectric windows are investigated using Particle-In-Cell (PIC) simulations. Initially baseline susceptibility diagrams are constructed analytically and compared with self-consistent, dynamic system trajectories. The power deposited on the surface of a dielectric window in an HPM system is considered using three different methods and the results of PIC simulations. Geometric mitigation is then considered by varying the window orientation with respect to the HPM electric held. Small angular deviations, less than 20 degrees, from the nominal case of normal incidence show dramatic changes in the susceptibility diagram. A materials approach to mitigation is then …

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Analysis And Application Of The Bi-Directional Scatter Distribution Function Of Photonic Crystals, Robert B. Lamott Mar 2009

Analysis And Application Of The Bi-Directional Scatter Distribution Function Of Photonic Crystals, Robert B. Lamott

Theses and Dissertations

Photonic crystals (PCs) are periodic structures built from materials with different refractive indices repeated at sub-wavelength intervals, which results in unusual optical characteristics, including narrowband laser protection, and zero reflectance and high absorption anomalies. Most of the research into the optical properties of PCs has concentrated only on the small range of wavelengths and angles where these effects occur. To better understand where all light leaving a PC is scattered, a Complete Angle Scatter Instrument was used to analyze the scatter from three Guided Mode Resonance Filters designed for laser protection. In the plane of incidence, measurements of the scatter …

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Investigation Of Electrical And Optical Properties Of Bulk Iii-V Ternary Semiconductors, Travis C. Gomez Mar 2009

Investigation Of Electrical And Optical Properties Of Bulk Iii-V Ternary Semiconductors, Travis C. Gomez

Theses and Dissertations

Bulk grown III-V ternary semiconductors of In0.08Ga0.92Sb and In0.15Ga0.85As were investigated through Hall-effect and photoluminescence measurements to determine carrier concentration, mobility, sheet resistivity, and luminescence spectrum. In the past, epitaxial layers of ternary compounds have been grown on binary compound substrates, and thus very limited lattice matched ternary alloys were available. Recently, bulk grown ternary substrates have been developed, and it has presented a renewed interest in using these substrates to grow high quality ternary compounds for use in many next generation optoelectronic devices. The results of photoluminescence (PL) study for the …

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Architecting Human Operator Trust In Automation To Improve System Effectiveness In Multiple Unmanned Aerial Vehicles (Uav), Eric A. Cring, Adam G. Lenfestey Mar 2009

Architecting Human Operator Trust In Automation To Improve System Effectiveness In Multiple Unmanned Aerial Vehicles (Uav), Eric A. Cring, Adam G. Lenfestey

Theses and Dissertations

Current Unmanned Aerial System (UAS) designs require multiple operators for each vehicle, partly due to imperfect automation matched with the complex operational environment. This study examines the effectiveness of future UAS automation by explicitly addressing the human/machine trust relationship during system architecting. A pedigreed engineering model of trust between human and machine was developed and applied to a laboratory-developed micro-UAS for Special Operations. This unprecedented investigation answered three primary questions. Can previous research be used to create a useful trust model for systems engineering? How can trust be considered explicitly within the DoD Architecture Framework? Can the utility of architecting …

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Low Probability Of Intercept Waveforms Via Intersymbol Dither Performance Under Multipath Conditions, Jonathan K. Keen Mar 2009

Low Probability Of Intercept Waveforms Via Intersymbol Dither Performance Under Multipath Conditions, Jonathan K. Keen

Theses and Dissertations

This thesis examines the effects of multipath interference on Low Probability of Intercept (LPI) waveforms generated using intersymbol dither. LPI waveforms are designed to be difficult for non-cooperative receivers to detect and manipulate, and have many uses in secure communications applications. In prior research, such a waveform was designed using a dither algorithm to vary the time between the transmission of data symbols in a communication system. This work showed that such a method can be used to frustrate attempts to use non-cooperative receiver algorithms to recover the data. This thesis expands on prior work by examining the effects of …

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