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Full-Text Articles in Engineering

United States Air Force Officer Manpower Planning Problem Via Approximate Dynamic Programming, Amelia E. Bradshaw Mar 2016

United States Air Force Officer Manpower Planning Problem Via Approximate Dynamic Programming, Amelia E. Bradshaw

Theses and Dissertations

The United States Air Force (USAF) is concerned with managing its officer corps to ensure sufficient personnel for mission readiness. Manpower planning for the USAF is a complex process which requires making decisions about accessions. Uncertainty about officer retention complicates such decisions. We formulate a Markov decision process model of the Air Force officer manpower planning problem (AFO-MPP) and utilize a least squares approximate policy iteration algorithm as an approximate dynamic programming (ADP) technique to attain solutions. Computational experiments are conducted on two AFO-MPP instances to compare the performance of the policy determined with the ADP algorithm to a benchmark …

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Using Multiple Objective Decision Analysis To Position Federal Product And Service Codes Within The Kraljic Portfolio Matrix, Robert T. Montgomery Mar 2016

Using Multiple Objective Decision Analysis To Position Federal Product And Service Codes Within The Kraljic Portfolio Matrix, Robert T. Montgomery

Theses and Dissertations

Despite the best efforts of the Federal Government to implement strategic sourcing, recent Government Accountability Office (GAO) reports highlight major procurement deficiencies and encourage the use of commercial best practices to identify and reap substantial savings. The Kraljic Portfolio Matrix (KPM) is considered the premier tool for purchasing organizations to determine which commercial best practices to utilize for different categories of spend. However, critics of the KPM point to its lack of analytical rigor and the absence of a simplistic quantitative methodology for implementation. The Air Force Installation Contracting Agency (AFICA), the centralized procurement arm for 79 USAF installations worldwide, …

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Radiation Effects On An Active Ytterbium-Doped Fiber Laser, Adam C. Poulin Mar 2016

Radiation Effects On An Active Ytterbium-Doped Fiber Laser, Adam C. Poulin

Theses and Dissertations

This is the first published research focused on the impact of gamma and mixed gamma/neutron radiation on an actively lasing ytterbium-doped fiber laser. While the gain medium of the ytterbium-doped fiber laser was irradiated, the power was measured in-situ and the spectrum was recorded intermittently. Two radiation sources were used, a 60Co cell and a reactor. Three irradiation experiments were conducted per radiation source; pristine fibers were used for the first two experiments, and fibers from the second experiment were re-irradiated for the third experiment. The results indicate that as the total dose increased linearly with time, the laser …

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Contingency Workload Demand Forecast Techniques For Cargo And Flying Hours, Calvin J. Bradshaw Iii Mar 2016

Contingency Workload Demand Forecast Techniques For Cargo And Flying Hours, Calvin J. Bradshaw Iii

Theses and Dissertations

Accurate forecasting of contingency workload demand for USTRANSCOM (USTC) is a herculean effort. Transportation Working Capital Fund (TWCF) managers rely on various subject matters outside and within the combatant command to estimate future workload. Since rates are set annually, when TWCF activities use incorrect or incomplete projections of workload, this leads to erroneous price structures and misaligned customer billing rates. The USTC leadership lacks the ability to accurately forecast workload demand, which is a key driver for service provider rate-setting. As a result, some customers perceive spiked rates and seek service from other competitors, which generates lost revenue, customer dissatisfaction …

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Evaluation Of Verification Approaches Applied To A Nonlinear Control System, Kerianne H. Gross Mar 2016

Evaluation Of Verification Approaches Applied To A Nonlinear Control System, Kerianne H. Gross

Theses and Dissertations

As the demand for increasingly complex and autonomous systems grows, designers may consider computational and artificial intelligence methods for more advanced, re- active control. While the performance gained by such increasingly intelligent systems may be superior to traditional control techniques, the lack of transparency in the systems and opportunity for emergent behavior limits their application in the field. New verification and validation methods must be developed to ensure the output of such controllers do not put the system or any people interacting with it in danger. This challenge was highlighted by the former Air Force Chief Scientist in his 2010 …

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Civil Engineer Company Grade Officer Training Needs Analysis For Contingency Operations, Brian S. Greszler Mar 2016

Civil Engineer Company Grade Officer Training Needs Analysis For Contingency Operations, Brian S. Greszler

Theses and Dissertations

In terms of active duty personnel, the USAF is the smallest it has ever been since its creation in 1947. With fewer personnel to accomplish essential tasks, the training of Airmen is more important than ever. Outdated and irrelevant training can lead to gaps in the knowledge of trainees. The purpose of this research was to analyze the training needs of Civil Engineer (CE) Company Grade Officers (CGOs) in the contingency environment. This was done by first conducting a Job Analysis (JA). The JA resulted in a list of 36 critical tasks and 58 important Knowledge, Skills, and Abilities (KSAs). …

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Autoencoded Reduced Clusters For Anomaly Detection Enrichment (Arcade) In Hyperspectral Imagery, Brenden A. Mclean Mar 2016

Autoencoded Reduced Clusters For Anomaly Detection Enrichment (Arcade) In Hyperspectral Imagery, Brenden A. Mclean

Theses and Dissertations

Anomaly detection in hyper-spectral imagery is a relatively recent and important research area. The shear amount of data available in a many hyper-spectral images makes the utilization of multivariate statistical methods and artificial neural networks ideal for this analysis. Using HYDICE sensor hyper-spectral images, we examine a variety of preprocessing techniques within a framework that allows for changing parameter settings and varying the methodological order of operations in order to enhance detection of anomalies within image data. By examining a variety of different options, we are able to gain significant insight into what makes anomaly detection viable for these images, …

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Integrity Determination For Image Rendering Vision Navigation, Sean M. Calhoun Mar 2016

Integrity Determination For Image Rendering Vision Navigation, Sean M. Calhoun

Theses and Dissertations

This research addresses the lack of quantitative integrity approaches for vision navigation, relying on the use of image or image rendering techniques. The ability to provide quantifiable integrity is a critical aspect for utilization of vision systems as a viable means of precision navigation. This research describes the development of two unique approaches for determining uncertainty and integrity for a vision based, precision, relative navigation system, and is based on the concept of using a single camera vision system, such as an electro-optical (EO) or infrared imaging (IR) sensor, to monitor for unacceptably large and potentially unsafe relative navigation errors. …

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Design And Analysis Of A Retroreflective Array For Ir Application, Michael E. Bollinger Mar 2016

Design And Analysis Of A Retroreflective Array For Ir Application, Michael E. Bollinger

Theses and Dissertations

This research investigates the adaptation of a Van Atta style of retrodirective array designed to work at 2 GHz to work in the infrared spectrum of 8-12 μm centered at 30 THz. The Computational Research and Engineering Acquisition Tools and Environments (CREATE) software suite and high performance computing (HPC) resources of the HPC Modernization program were utilized to model and simulate multiple steps of an adaptation process to illustrate and examine the incremental performance changes of frequency scaling the design. Two different substrate materials, germanium and hafnium oxide, are evaluated as the dielectric materials, and a comparison of the broadband …

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Geosynchronous Binary Object Detection, Patrick B. Cunningham Mar 2016

Geosynchronous Binary Object Detection, Patrick B. Cunningham

Theses and Dissertations

This paper will compare competing methods for optically detecting binary objects. This is mostly intended for use in Space Situational Awareness (SSA), though has the potential to be used in other applications. The first method referred to as, “Single Object Detection” is a versatile algorithm which is currently used to detect extraterrestrial objects. However, it does not take into account interference by a nearby object. Therefore a second algorithm is investigated, referred to as “Binary Object Detection”, which does. The binary detection algorithm proved to have a comparable or superior Receiver Operating Characteristic (ROC) curve (based upon the area under …

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Towards Automated Aerial Refueling: Real Time Position Estimation With Stereo Vision, Bradley D. Denby Mar 2016

Towards Automated Aerial Refueling: Real Time Position Estimation With Stereo Vision, Bradley D. Denby

Theses and Dissertations

Aerial refueling is essential to the United States Air Force (USAF) core mission of rapid global mobility. However, in-flight refueling is not available to remotely piloted aircraft (RPA) or unmanned aerial systems (UAS). As reliance on drones for intelligence, surveillance, and reconnaissance (ISR) and other USAF core missions grows, the ability to automate aerial refueling for such systems becomes increasingly critical. New refueling platforms include sensors that could be used to estimate the relative position of an approaching aircraft. Relative position estimation is a key component to solving the automated aerial refueling (AAR) problem. Analysis of data from a one-seventh …

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Satellite Ephemeris Correction Via Remote Site Observation For Star Tracker Navigation Performance Improvement, Jorge E. Diaz Mar 2016

Satellite Ephemeris Correction Via Remote Site Observation For Star Tracker Navigation Performance Improvement, Jorge E. Diaz

Theses and Dissertations

In order for celestial navigation observing satellites to provide accurate positioning estimates, precise ephemerides of the observed satellites are necessary. This work analyzed a method to correct for satellite ephemeris to be used in celestial navigation applications. This correction is the measured angle differences between the expected location of the satellite, which is given by propagating publicly available Two-Line Elements (TLE), and their observed angles from a precisely known reference site. Therefore, the angle difference can be attributed completely to satellite ephemeris error assuming instrument error was accounted for. The intent is to calculate this correction from the reference site …

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Airborne Directional Networking: Topology Control Protocol Design, Barry C. Geise Mar 2016

Airborne Directional Networking: Topology Control Protocol Design, Barry C. Geise

Theses and Dissertations

This research identifies and evaluates the impact of several architectural design choices in relation to airborne networking in contested environments related to autonomous topology control. Using simulation, we evaluate topology reconfiguration effectiveness using classical performance metrics for different point-to-point communication architectures. Our attention is focused on the design choices which have the greatest impact on reliability, scalability, and performance. In this work, we discuss the impact of several practical considerations of airborne networking in contested environments related to autonomous topology control modeling. Using simulation, we derive multiple classical performance metrics to evaluate topology reconfiguration effectiveness for different point-to-point communication architecture …

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Dynamic Honeypot Configuration For Programmable Logic Controller Emulation, Kyle A. Girtz Mar 2016

Dynamic Honeypot Configuration For Programmable Logic Controller Emulation, Kyle A. Girtz

Theses and Dissertations

Attacks on industrial control systems and critical infrastructure are on the rise. Important systems and devices like programmable logic controllers are at risk due to outdated technology and ad hoc security measures. To mitigate the threat, honeypots are deployed to gather data on malicious intrusions and exploitation techniques. While virtual honeypots mitigate the unreasonable cost of hardware-replicated honeypots, these systems often suffer from a lack of authenticity due to proprietary hardware and network protocols. In addition, virtual honeynets utilizing a proxy to a live device suffer from performance bottlenecks and limited scalability. This research develops an enhanced, application layer emulator …

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Using Phase Screens To Synthesize Electromagnetic Gaussian-Schell Model Sources With Desired Amplitude, Coherence, And Polarization, Christopher K. Kokoczka Mar 2016

Using Phase Screens To Synthesize Electromagnetic Gaussian-Schell Model Sources With Desired Amplitude, Coherence, And Polarization, Christopher K. Kokoczka

Theses and Dissertations

An electromagnetic Gaussian-Schell model (EGSM) source is built with desired coherence, amplitude, and polarization using correlated phase screens based on re- search conducted in Refs. [2, 9]. A new method of amplitude control is presented and tested using spatial light modulators (SLM). A brief review of theory and concepts is discussed followed by methods of how to build an EGSM source, correlated phase screens, and control amplitude using SLM gratings. The experimental set-up is presented which builds EGSM sources that demonstrate desired amplitude, coherence, and polarization. Irradiance correlation, degree of polarization, and Stokes parameters S0 and S1 are …

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Tunable Terahertz Metamaterials With Germanium Telluride Components, Christopher H. Kodama Mar 2016

Tunable Terahertz Metamaterials With Germanium Telluride Components, Christopher H. Kodama

Theses and Dissertations

Terahertz (THz) technology is an emerging field with many exciting applications. THz waves can be used to locate explosives and illicit drugs in security applications, or DNA and other molecule resonances in medical applications. THz frequencies represent the next level of modern, high-speed computing, but they also can be used for covert battlefield communications links. Metamaterials are an integral part of THz technology because they can be used to create exotic material properties—permittivities and permeabilities—in a part of the frequency spectrum that is otherwise rather empty and passive. This work aims to acquire a fuller understanding of THz metamaterials in …

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A Practical Wireless Exploitation Framework For Z-Wave Networks, Joseph L. Hall Mar 2016

A Practical Wireless Exploitation Framework For Z-Wave Networks, Joseph L. Hall

Theses and Dissertations

Wireless Sensor Networks (WSN) are a growing subset of the emerging Internet of Things (IoT). WSNs reduce the cost of deployment over wired alternatives; consequently, use is increasing in home automation, critical infrastructure, smart metering, and security solutions. Few published works evaluate the security of proprietary WSN protocols due to the lack of low-cost and effective research tools. One such protocol is ITU-T G.9959-based Z-Wave, which maintains wide acceptance within the IoT market. This research utilizes an open source toolset, presented herein, called EZ-Wave to identify methods for exploiting Z-Wave devices and networks using Software-Defined Radios (SDR). Herein, techniques enabling …

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Characterization For The Development Of The Hybrid Multi-Junction Silicon Germanium Solar Cell, Jimmy J. Lohrman Mar 2016

Characterization For The Development Of The Hybrid Multi-Junction Silicon Germanium Solar Cell, Jimmy J. Lohrman

Theses and Dissertations

Based on the previous development of the hybrid multi-junction silicon (HMJ-Si) solar cell, this work characterized the preceding design for the development of the hybrid multi-junction silicon germanium (HMJ-SiGe) solar cell. Seven focus areas were investigated: diffraction pattern generation, photon propagation, silicon diffusion processing, ohmic contacts, the distributed Bragg reflector (DBR), the Fresnel zone plate (FZP), and the germanium/germanium telluride (Ge/GeTe) pn-junction Diffraction patterns were theoretically examined, and contact grating design characterization for reflectance and transmittance properties was modeled using rigorous coupled wave analysis. An improved silicon diffusion process follower was developed, and theoretical study and experimental assessment were accomplished …

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Non-Linear Optimization Applied To Angle-Of-Arrival Satellite Based Geo-Localization For Biased And Time Drifting Sensors, Daniel E. Levy Mar 2016

Non-Linear Optimization Applied To Angle-Of-Arrival Satellite Based Geo-Localization For Biased And Time Drifting Sensors, Daniel E. Levy

Theses and Dissertations

Multiple sensors are used in a variety of geolocation systems. Many use Time Difference of Arrival (TDOA) or Received Signal Strength (RSS) measurements to locate the most likely location of a signal. When an object does not emit a classical RF signal, Angle of Arrival (AOA) measurements become more feasible than TDOA or RSS measurements. AOA measurements can be created from any sensor platform with any sort of camera. When location and attitude knowledge of the sensor passive objects can be tracked. A Non-Linear Optimization (NLO) method for calculating the most likely estimate from AOA measurements has been created in …

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Interference Suppression Using Knowledge-Aided Subarray Pattern Synthesis, David A. New Mar 2016

Interference Suppression Using Knowledge-Aided Subarray Pattern Synthesis, David A. New

Theses and Dissertations

Most phased array systems subarray many antenna elements into far fewer digitized channels. While having more degrees of freedom (DOF) yields better performance, adding channels to create more digital DOF increases system cost and data throughput requirements. A subarray itself constitutes a phased array with as many DOF as it has antenna element weights. Typically, only one degree of freedom is used to steer the maximum gain direction of the subarray pattern. For typical antenna geometries a single subarray will provide many more spatial DOF than there are digitized channels. The inherent DOF of the subarrays could be used to …

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Implementation And Performance Of Factorized Backprojection On Low-Cost Commercial-Off-The-Shelf Hardware, Alec C. Rasmussen Mar 2016

Implementation And Performance Of Factorized Backprojection On Low-Cost Commercial-Off-The-Shelf Hardware, Alec C. Rasmussen

Theses and Dissertations

Traditional Synthetic Aperture Radar (SAR) systems are large, complex, and expensive platforms that require significant resources to operate. The size and cost of the platforms limits the potential uses of SAR to strategic level intelligence gathering or large budget research efforts. The purpose of this thesis is to implement the factorized backprojection SAR image processing algorithm in the C++ programming language and test the code's performance on a low cost, low size, weight, and power (SWAP) computer: a Raspberry Pi Model B. For a comparison of performance, a baseline implementation of filtered backprojection is adapted to C++ from pre-existing MATLAB® …

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Visual-Ins Using A Human Operator And Converted Measurements, Turner J. Montgomery Mar 2016

Visual-Ins Using A Human Operator And Converted Measurements, Turner J. Montgomery

Theses and Dissertations

A method human operated INS aiding is explored in which the pilot identifies and tracks a ground feature of unknown position over a short measurement epoch using an E/O sensor. One then refers to Visual-INS. In contrast to current research trends, a human operator is entrusted with visually tracking the ground feature. In addition, a less conventional measurement linearization technique is applied to generate “converted” measurements. A linear regression algorithm is then applied to the converted measurements providing an estimate of the INS horizontal velocity error and accelerometer biases. At the completion of the measurement epoch, the INS is corrected …

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Comparison Of Methods For Radio Position Of Non-Emitting Dismounts, Collin J. Seanor Mar 2016

Comparison Of Methods For Radio Position Of Non-Emitting Dismounts, Collin J. Seanor

Theses and Dissertations

Radio Tomographic Imaging (RTI) is a form of Device Free Passive Localization (DFPL) that utilizes the Received Signal Strength (RSS) values from a collection of wireless transceivers to produce an image in order to localize a subject within a Wireless Sensor Network (WSN). Radio Mapping is another form of DFPL that can utilize the same RSS values from a WSN to localize a subject by comparing recent values to a set of calibration data. RTI and Radio Mapping have never been directly compared to one another as a means of localization within a WSN. The goal of this research is …

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Dynamic Network Security Control Using Software Defined Networking, Michael C. Todd Mar 2016

Dynamic Network Security Control Using Software Defined Networking, Michael C. Todd

Theses and Dissertations

This thesis develops and implements a process to rapidly respond to host level security events using a host agent, Software Defined Networking and OpenFlow updates, role based flow classes, and Advanced Messaging Queuing Protocol to automatically update configuration of switching devices and block malicious traffic. Results show flow table updates are made for all tested levels in less than 5.27 milliseconds and event completion time increased with treatment level as expected. As the number of events increases from 1,000 to 50,000, the design scales logarithmically caused mainly by message delivery time. Event processing throughput is limited primarily by the message …

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Field-Based Phase Retrieval Using Under-Sampled Data, Tatsuki L. Watts Mar 2016

Field-Based Phase Retrieval Using Under-Sampled Data, Tatsuki L. Watts

Theses and Dissertations

A phase retrieval algorithm designed for use with under-sampled astronomical data is developed in this thesis. Blind-deconvolution, Gerchberg Saxton (GS), and a field-based compass search are combined into an algorithm capable of recovering Zernike coefficients 4 through 11 from single frames of noisy, under-sampled data without the need to unwrap the recovered phase. The performance of the algorithm in data under-sampled by a factor of 2 is compared the performance of the algorithm on Nyquist-sampled data. In simulation trials, the magnitudes of all 8 estimated Zernike coefficients converged to within half a wave of the true values for 98% of …

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Application Of Non-Rated Line Officer Attrition Levels And Career Field Stability, Christine L. Zens Mar 2016

Application Of Non-Rated Line Officer Attrition Levels And Career Field Stability, Christine L. Zens

Theses and Dissertations

The Air Force monitors the strength of its active duty officer force and attempts to achieve the difficult challenge of employing a diversity of talent among career specialties and experience levels. This study completes two objectives, predicting future manning levels for 23 career fields, and providing a statistical framework to assess the stability of these fields. The first part of the study applies regression and survival analysis to subpopulations within the active duty Air Force officer corps, and then aggregates them by year to forecast future personnel levels. Four career fields are considered, including Acquisitions (ACQ), Logistics (LOG), Support (SPT), …

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Modeling The Components Of An Economy As A Complex Adaptive System, Richard J. Mickelsen Mar 2016

Modeling The Components Of An Economy As A Complex Adaptive System, Richard J. Mickelsen

Theses and Dissertations

Complex systems science is a relatively new discipline and has not been widely applied to the field of economics. Much of current economic theory relies on principles of constrained optimization and often fails to see economic variables as part of an interconnected network. While tools for forecasting economic indicators are based primarily on autoregressive techniques, these techniques are not always well-suited to predicting the future performance of highly volatile data sets such as the stock market. This research portrays the stock market as one component of a networked system of economic variables, with the federal funds rate acting as an …

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Rate Setting Analysis: A Statistical Approach To Outlier Analysis In The Rate Setting Process Within The United States Transportation Command, Warren B. Mcgriff Mar 2016

Rate Setting Analysis: A Statistical Approach To Outlier Analysis In The Rate Setting Process Within The United States Transportation Command, Warren B. Mcgriff

Theses and Dissertations

The rate setting process implemented by the USTRANSCOM J8 Program Analysis & Financial Management Directorate (USTC J8 or TCJ8) is of importance, as accurate rates yield proper and equitable recoupment of costs from customers and ensure USTC can achieve an accurate Net Operating Result (NOR) in each given year. This research sought to identify areas in which the current rate setting methodology can be improved. We initially examined the use of six months of historical cost data versus a full year of data to set rates, concluding that there is not a statistically significant difference with respect to their relative …

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Long-Term Impacts Of Military Drawdown On The Industrial Base, Anton H. Martyn Mar 2016

Long-Term Impacts Of Military Drawdown On The Industrial Base, Anton H. Martyn

Theses and Dissertations

Since World War II, competition in the defense industry has fallen by over 90 percent. Over half of contracts currently executed by the United States Navy and Air Force are awarded without any competition. With the recent defense budget cuts, and an extended period of reduced defense spending ahead, more of which is going to sustainment and overhead than ever before, each year prime contractors are fighting over an even smaller piece of the procurement pie, which could have a deleterious effect on national security if these contractors go out of business or further consolidate through mergers. This study used …

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A Response Surface Validation Of A Quantum Key Distribution Model, Jacob M. Ehrlich Mar 2016

A Response Surface Validation Of A Quantum Key Distribution Model, Jacob M. Ehrlich

Theses and Dissertations

The need for secure communication in the presence of an adversary introduced the field of cryptology -- the practice and study of techniques for secure communication. A common method to secure communication is to distribute a secret key among authorized parties so they can encrypt and decrypt messages between each other. By doing so, ideally, any messages intercepted by a third party are meaningless. An innovative technique to distribute a shared key is Quantum Key Distribution (QKD). QKD uses laws of quantum mechanics to generate and distribute such keys. The purpose of this thesis is to validate an existing mathematical …

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