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Full-Text Articles in Engineering

Investigation Of Electromagnetic Signatures Of A Fpga Using An Aprel Em-Isight System, Karynn A. Sutherlin Dec 2015

Investigation Of Electromagnetic Signatures Of A Fpga Using An Aprel Em-Isight System, Karynn A. Sutherlin

Theses and Dissertations

Large military platforms have encountered major performance and reliability issues due to an increased number of incidents with counterfeit electronic parts. This has drawn the attention of Department of Defense (DOD) leadership making detection and avoidance of counterfeit electronic parts a top issue for national defense. More defined regulations and processes for identifying, reporting, and disposing of counterfeit electronic parts are being revised to raise awareness for this aggregating issue, as well as enhance the detection of these parts. Multiple technologies are currently employed throughout the supply chain to detect counterfeit electronic parts. These methods are often costly, time-consuming, and …


Feature Selection And Classifier Development For Radio Frequency Device Identification, Trevor J. Bihl Dec 2015

Feature Selection And Classifier Development For Radio Frequency Device Identification, Trevor J. Bihl

Theses and Dissertations

The proliferation of simple and low-cost devices, such as IEEE 802.15.4 ZigBee and Z-Wave, in Critical Infrastructure (CI) increases security concerns. Radio Frequency Distinct Native Attribute (RF-DNA) Fingerprinting facilitates biometric-like identification of electronic devices emissions from variances in device hardware. Developing reliable classifier models using RF-DNA fingerprints is thus important for device discrimination to enable reliable Device Classification (a one-to-many looks most like assessment) and Device ID Verification (a one-to-one looks how much like assessment). AFITs prior RF-DNA work focused on Multiple Discriminant Analysis/Maximum Likelihood (MDA/ML) and Generalized Relevance Learning Vector Quantized Improved (GRLVQI) classifiers. This work 1) introduces a …


Multi-Mode Analysis Of Dual Ridged Waveguide Systems For Material Characterization, Jason G. Crosby Sep 2015

Multi-Mode Analysis Of Dual Ridged Waveguide Systems For Material Characterization, Jason G. Crosby

Theses and Dissertations

In this dissertation, two nondestructive dual ridged waveguide (DRWG) material characterization systems are investigated. The single and clamped DRWG probe geometries were analyzed in previous work; however, that research only incorporated the dominant DRWG mode. Here, that restriction is removed and the existence of evanescent higher- order modes is considered. Theoretical analysis of the single and clamped DRWG probes is presented and discussed. The approach taken here is similar to that presented in previous research: Love's equivalence theorem is used to remove the DRWG apertures which are replaced with equivalent magnetic currents radiating in the presence of the background parallel-plate …


Novel Applications Of A Thermally Tunable Bistable Buckling Silicon-On-Insulator (Soi) Microfabricated Membrane, Robert A. Lake Sep 2015

Novel Applications Of A Thermally Tunable Bistable Buckling Silicon-On-Insulator (Soi) Microfabricated Membrane, Robert A. Lake

Theses and Dissertations

Buckled membranes are commonly used microelectromechanical systems (MEMS) structures. Recent work has demonstrated that the deflection and stiffness of these membranes can be tuned through localized joule heating. These devices were implemented into the design and fabrication of two novel device applications, a tunable pressure sensor and a steerable micromirror. A differential pressure across the membrane causes de reflection, up or down, which can be measured and related to a specific pressure. By tuning the stiffness of the membrane, its pressure response is varied providing a wider range of application for the pressure sensor. A 2.0mm by 2.0mm square membrane …


Exploitation Of Unintentional Ethernet Cable Emissions Using Constellation Based-Distinct Native Attribute (Cb-Dna) Fingerprints To Enhance Network Security, Timothy J. Carbino Sep 2015

Exploitation Of Unintentional Ethernet Cable Emissions Using Constellation Based-Distinct Native Attribute (Cb-Dna) Fingerprints To Enhance Network Security, Timothy J. Carbino

Theses and Dissertations

This research contributed to the AFIT's Radio Frequency Intelligence (RFINT) program by developing a new device discrimination technique called Constellation-Based Distinct Native Attribute (CB-DNA) Fingerprinting. This is of great interest to the Air Force Research Lab (AFRL), Sensor Directorate, who supported the research and now have new method for improving network security. CB-DNA fingerprints are used to authenticate wired network device identities, thwart unauthorized access, and augment traditional bit-level security measures that area easily bypassed by skilled hackers. Similar to human fingerprint features that uniquely identify individuals, CB-DNA uniquely identifies communication devices and improves the rate at which unauthorized rogue …


Static Scene Statistical Non-Uniformity Correction, Adrian M. Catarius Mar 2015

Static Scene Statistical Non-Uniformity Correction, Adrian M. Catarius

Theses and Dissertations

Non-Uniformity Correction (NUC) is required to normalize imaging detector Focal-Plane Array (FPA) outputs due to differences in the end-to-end photoelectric responses between pixels. Currently, multi-point NUC methods require static, uniform target scenes of a known intensity for calibration. Conversely, scene-based NUC methods do not require a priori knowledge of the target but the target scene must be dynamic. The new Static Scene Statistical Non-Uniformity Correction (S3NUC) algorithm was developed to address an application gap left by current NUC methods. S3NUC requires the use of two data sets of a static scene at different mean intensities but does not require a …


Initial Implementation And Testing Of A Tightly-Coupled Imu/Pseudolite System, James E. C. Kawecki Mar 2015

Initial Implementation And Testing Of A Tightly-Coupled Imu/Pseudolite System, James E. C. Kawecki

Theses and Dissertations

Currently, the 746th Test Squadrons (746th TS) Central Inertial and GPS Test Facility (CIGTF) operates one of the most accurate truth reference systems, called the CIGTF Reference System (CRS). CIGTF will be replacing the CRS with a new references system called UHARS (Ultra High Accuracy Reference System). UHARS will differ from CRS by adding the ability to use a non-GPS pseudolite system, as a new measurement source. This research effort describes the design of the extended Kalman filter which is developed in AFIT's SPIDER filter framework which implements a tightly-coupled pseudolite/INS filter.


Estimating Single And Multiple Target Locations Using K-Means Clustering With Radio Tomographic Imaging In Wireless Sensor Networks, Jeffrey K. Nishida Mar 2015

Estimating Single And Multiple Target Locations Using K-Means Clustering With Radio Tomographic Imaging In Wireless Sensor Networks, Jeffrey K. Nishida

Theses and Dissertations

Geolocation involves using data from a sensor network to assess and estimate the location of a moving or stationary target. Received Signal Strength (RSS), Angle of Arrival (AoA), and/or Time Difference of Arrival (TDoA) measurements can be used to estimate target location in sensor networks. Radio Tomographic Imaging (RTI) is an emerging Device-Free Localization (DFL) concept that utilizes the RSS values of a Wireless Sensor Network (WSN) to geolocate stationary or moving target(s). The WSN is set up around the Area of Interest (AoI) and the target of interest, which can be a person or object. The target inside the …


A Novel Analysis Of Performance Classification And Workload Prediction Using Electroencephalography (Eeg) Frequency Data, Donovan L. Ricks Mar 2015

A Novel Analysis Of Performance Classification And Workload Prediction Using Electroencephalography (Eeg) Frequency Data, Donovan L. Ricks

Theses and Dissertations

Across the DOD each task an operator is presented with has some level of difficulty associated with it. This level of difficulty over the course of the task is also known as workload, where the operator is faced with varying levels of workload as he or she attempts to complete the task. The focus of the research presented in this thesis is to determine if those changes in workload can be predicted and to determine if individuals can be classified based on performance in order to prevent an increase in workload that would cause a decline in performance in a …


Non-Linear Optimization Applied To Angle-Of-Arrival Satellite-Based Geolocation With Correlated Measurements, Joshua S. Sprang Mar 2015

Non-Linear Optimization Applied To Angle-Of-Arrival Satellite-Based Geolocation With Correlated Measurements, Joshua S. Sprang

Theses and Dissertations

A common remote sensing application is producing geolocation estimates for an object of interest from multiple sensor platforms. Geolocation estimates are desired to help improve situational awareness when dealing with space objects that do not actively broadcast their location. A depiction of the error parameters are calculated in conjunction with the positional estimates. Problems occur when multiple measurements from a single sensor are used to estimate a location due to correlations in sensor error. A non-linear optimization approach is presented for determining geolocation estimates and their associated error parameters. The error parameters directly reflect the error present on the individual …


Characterizing Multiple Wireless Sensor Networks For Large-Scale Radio Tomography, Tan Van Mar 2015

Characterizing Multiple Wireless Sensor Networks For Large-Scale Radio Tomography, Tan Van

Theses and Dissertations

Radio Tomographic Imaging (RTI) is an emerging Device-Free Passive Localization (DFPL) technology that uses a collection of cheap wireless transceivers to form a Wireless Sensor Network (WSN). Unlike device-based active localization, DFPL does not require a target of interest to be wearing any kind of device. The basic concept of RTI utilizes the changes in Received Signal Strength (RSS) between the links of each transceiver to create an attenuation image of the area. This image can then be used for target detection, tracking, and localization. Each transceiver in the WSN must transmit sequentially to prevent collisions. This is not a …


Subtractive Plasma-Assisted-Etch Process For Developing High Performance Nanocrystalline Zinc-Oxide Thin-Film-Transistors, Thomas M. Donigan Mar 2015

Subtractive Plasma-Assisted-Etch Process For Developing High Performance Nanocrystalline Zinc-Oxide Thin-Film-Transistors, Thomas M. Donigan

Theses and Dissertations

Thin-Film-Transistors (TFTs) employing undoped zinc-oxide (ZnO) thin-films are currently being investigated by the Air Force for microwave switching applications. Since the on-resistance (R(on)) of the device scales with channel length (LC), ZnO TFT optimization should be focused on reducing LC, therefore minimizing the associated insertion losses. In this research, deep sub-micron scaling of ZnO TFTs was undertaken using a subtractive reactive-ion-etch (RIE) process. Under optimum processing conditions, ZnO TFTs with LC as small as 155 nm were successfully demonstrated. The active ZnO channels of the TFTs were patterned by selective SF6-RIE of a tungsten ohmic film through electron-beam defined openings …


Gate-Level Commercial Microelectronics Verification With Standard Cell Recognition, Leleia A. Hsia Mar 2015

Gate-Level Commercial Microelectronics Verification With Standard Cell Recognition, Leleia A. Hsia

Theses and Dissertations

Within the past two decades, the problem of counterfeit hardware has gained significant attention within the Department of Defense (DoD). Counterfeit electronics compromise national security systems as they may fail to meet durability requirements and/or contain malicious circuits [6, 16, 17]. This necessitates the development of methods to detect counterfeit electronics and prevent the counterfeit electronics from entering DoD systems. The DARPA TRUST program was established to address the need to verify integrated circuit (IC) electronics. This research describes the development of standard cell recognition (SCR) software intended to resolve conflicts in prior TRUST related applications of commercial software to …


Single Platform Geolocation Of Radio Frequency Emitters, Eric J. Bailey Mar 2015

Single Platform Geolocation Of Radio Frequency Emitters, Eric J. Bailey

Theses and Dissertations

The focus of this research is on single platform geolocation methods where the position of a single stationary radio frequency emitter is estimated from multiple simulated angle and frequency of arrival measurements taken from a single moving receiver platform. The analysis scenario considered consists of a single 6U CubeSat in low earth orbit receiving radio frequency signals from a stationary emitter located on the surface of the Earth. A multiple element receive antenna array and the multiple signal classification algorithm are used to estimate the angles of arrival of an impinging signal. The maximum likelihood estimator is used to estimate …


Materials Characterization And Microelectronic Implementation Of Metal-Insulator Transition Materials And Phase Change Materials, Alexander H. Gwin Mar 2015

Materials Characterization And Microelectronic Implementation Of Metal-Insulator Transition Materials And Phase Change Materials, Alexander H. Gwin

Theses and Dissertations

Vanadium dioxide (VO2) is a metal-insulator transition (MIT) material, and germanium telluride (GeTe) is a phase change material (PCM), both of which undergo several orders of magnitude increase in electrical conductivity from room temperature to their transition temperatures. They are candidates for many important technologies, including ultra-fast electronic memory, optical switches and filters, and active layers in terahertz metamaterials, among others. The physical mechanisms causing the phase transitions in these materials are explained and investigated experimentally. These materials were incorporated into six types of microelectronic devices, which were designed, fabricated, and tested at the Air Force Institute of …


Urban Environment Navigation With Real-Time Data Utilizing Computer Vision, Inertial, And Gps Sensors, Johnathan L. Rohde Mar 2015

Urban Environment Navigation With Real-Time Data Utilizing Computer Vision, Inertial, And Gps Sensors, Johnathan L. Rohde

Theses and Dissertations

The purpose of this research was to obtain a navigation solution that used real data, in a degraded or denied global positioning system (GPS) environment, from low cost commercial o the shelf sensors. The sensors that were integrated together were a commercial inertial measurement unit (IMU), monocular camera computer vision algorithm, and GPS. Furthermore, the monocular camera computer vision algorithm had to be robust enough to handle any camera orientation that was presented to it. This research develops a visual odometry 2-D zero velocity measurement that is derived by both the features points that are extracted from a monocular camera …


Unique Two-Way Field Probe Concept Utilizing A Geodesic Sphere And Quad-Rotor, Travis A. Albee Mar 2015

Unique Two-Way Field Probe Concept Utilizing A Geodesic Sphere And Quad-Rotor, Travis A. Albee

Theses and Dissertations

Surveying the test volume of a radar range normally involves utilizing an antenna field probe to measure the electromagnetic field in that volume of space. Today, field probes vary in size and shape and can be difficult and time consuming to setup. They also have a limited range of motion due to their support structure and translational mechanism, which also has scattering mechanisms that can perturb the field they are measuring. Field probes are useful, but because of these shortcomings they can provide limited characterization of the field illuminating the measurement area. Leveraging quad-rotor technology, coupled with a two-way probe …


Identifying Image Manipulation Software From Image Features, Devlin T. Boyter Mar 2015

Identifying Image Manipulation Software From Image Features, Devlin T. Boyter

Theses and Dissertations

As technology steadily increases in the field of image manipulation, determining which software was used to manipulate an image becomes increasingly complex for law enforcement and intelligence agencies. To combat this difficult problem, new techniques that examine the artifacts left behind by a specific manipulation are converted to features for classification. This research implemented four preexisting image manipulation detection techniques into a framework of modules: Two-Dimensional Second Derivative, One-Dimensional Zero Crossings, Quantization Matrices Identification, and File Metadata analysis. The intent is the creation of a framework to develop a capability to determine which specific image manipulation software program manipulated an …


Computational Electromagnetic Studies For Low-Frequency Compensation Of The Reflector Impulse-Radiating Antenna, Casey E. Fillmore Mar 2015

Computational Electromagnetic Studies For Low-Frequency Compensation Of The Reflector Impulse-Radiating Antenna, Casey E. Fillmore

Theses and Dissertations

The reflector impulse-radiating antenna (IRA) is considered to meet the requirement for a wideband, directional antenna with short temporal response and small electrical footprint. Standard reflector IRA designs are modeled and performance is simulated using full-wave computational electromagnetic (CEM) software. Characterization of the standard designs reveals the possible existence of wide, frequency-independent backlobes containing nearly 40% of the radiated power at high frequencies. These undesirable backlobes have never been hypothesized, predicted or measured, likely due in part to their alignment outside the primary measurement planes. At the lowest operating frequencies, the reflector IRA is unaffected by backlobes, but is characterized …


Electrical And Physical Property Characterization Of Single Walled Carbon Nanotube Ink For Flexible Printed Electronics, Kristian E. Warner Jr. Mar 2015

Electrical And Physical Property Characterization Of Single Walled Carbon Nanotube Ink For Flexible Printed Electronics, Kristian E. Warner Jr.

Theses and Dissertations

This research presents a method of characterizing single-walled carbon nanotube (SWCNT) ink. This research also examines the results of our characterization efforts. First, the process of ink jet printing SWCNT ink onto organic and inorganic substrates is discussed. Next, the tests for measuring sheet resistance, conductance, inductance, adherence, thickness, roll-off, and S-parameters of the ink are described. Results and findings of the research are presented. The SWCNT ink created by Brewer Science © is shown to be an effective material for additive manufacturing using an aerosol jet printer, but not an inkjet printer. The ink is shown to have a …