Electrical and Electronics Commons^™

Fault Modeling And Test Vector Generation For Asic Devices Exposed To Space Single Event Environment, Ahmed Mohamed

Theses and Dissertations

This work aims at providing a concise automated flow to predict the effect of Single Event Transients (SETs) on ASIC chips by developing a method to characterize the circuit susceptibility to SET pulses propagation and then generation of the required input vectors that sensitize the victim paths. A new enhanced method for SET electrical propagation modeling is proposed and compared to a previously published analytical model. The method was applied on different standard cells libraries built over XFAB Xh018 technology and verified for accuracy against simulations. The new method showed enhancement in accuracy compared with previous work in literature. Industrial …

Commuting Compositions For Quantum Circuit Reduction, Brenna R. Cole

Theses and Dissertations

Quantum circuit simplification improves program execution on quantum hardware by reducing error from prolonged environmental interaction and noisy gate operations. One simplification technique is template matching, which repeatedly conducts local optimization by replacing small sequences of gates within a circuit by optimized versions. Underlying this method is the problem of identifying sequences matching templates. This is challenging because some, but not all, gates can commute within a circuit. This means there may not be a subcircuit that matches a template in the original circuit specification, but a match may exist in an equivalent rearrangement of gates. In such cases, certain …

Charge Mitigation Technologies For Aircraft Platforms, Mitchell L. Rudy

Theses and Dissertations

Research into ion-based advanced propulsion systems, such as air-breathing Hall effect thrusters on high-velocity aircraft and ion-propelled thrusters on spacecraft, necessitates addressing accompanying residual electric charge accumulation on the ungrounded flight platform. An experimental testbed was constructed to assess charge mitigation technologies and their effectiveness on aircraft. A Van de Graaff generator provided static charge accumulation levels exceeding a megavolt when combined with a high voltage direct current source generator. This research attached an isolated airfoil structure to the Van de Graaff generator's lower terminal to measure the induced leakage current under various applied environmental conditions, including up to three …

Robust Scandium Aluminum Nitride Mems Resonators For L Band Operation In Orbital Environments, Israel W. Dunk

Theses and Dissertations

This thesis investigates AlN alloyed with scandium in a variety of resonator architectures including WEM, overtone WEM, LEM, and SAW that have the potential to achieve high levels of electrical performance and environmental robustness. SAW resonators operating near 370 MHz are fabricated on polycrystalline Sc_.37Al_.63N, and AlN with the resulting devices compared and conclusions drawn as to the merits of each material. The design and fabrication of SAW devices is discussed in detail, with the operating characteristics of these resonators then tested both electrically and mechanically. Mechanical characterisation includes analysis of vibration and shock effects on …

Surface Defect Detection In Aircraft Skin & Visual Navigation Based On Forced Feature Selection Through Segmentation, Tyler B. Hussey

Theses and Dissertations

Visual inspection of aircraft skin for surface defects is an area of maintenance that is particularly intensive for time and manpower. One novel way to combat this problem is through the use of computer vision and the advent of Artificial Neural Networks (ANN), or more specifically, semantic segmentation via Convolutional Neural Networks (CNN). The research in the paper explores the use of semantic segmentation of aerial imagery as a way to force feature selection onto key areas of an image that might be more likely to correspond under seasonal variations. Utilizing feature selection and matching on the masked aerial image …

Supporting Space Domain Awareness Through The Development And Analysis Of Space Object Detection Algorithms Employed By Ground-Based Telescopes, Connor A. Paw

Theses and Dissertations

Detection algorithms are instrumental in maintaining space domain awareness, specifically in the observation, monitoring, and categorization of unknown space objects. State of the art detection algorithms utilize a matched filter or a spatial correlator on long exposure image data to make pixel-wise detection decisions. This thesis investigates the advantages and practical potential of two different post-processing detection algorithms that can be employed by ground-based telescopes. The first algorithm explored is based on a long exposure Fourier domain processing technique, while the second is centered around frame selection from a series of short exposure images. The results of the experiments performed …

A General Framework For Characterizing And Evaluating Attacker Models For Cps Security Assessment, Christopher S. Deloglos, Christopher Deloglos

Theses and Dissertations

Characterizing the attacker’s perspective is essential to assessing the security posture and resilience of cyber-physical systems. The attacker’s perspective is most often achieved by cyber-security experts (e.g., red teams) who critically challenge and analyze the system from an adversarial stance. Unfortunately, the knowledge and experience of cyber-security experts can be inconsistent leading to situations where there are gaps in the security assessment of a given system. Structured security review processes (such as TAM, Mission Aware, STPA-SEC, and STPA-SafeSec) attempt to standardize the review processes to impart consistency across an organization or application domain. However, with most security review processes, the …

Perovskite Thin Films Annealed In Supercritical Fluids For Efficient Solar Cells, Gilbert Annohene

Theses and Dissertations

In the field of photovoltaics, scientists and researchers are working fervently to produce a combination of efficient, stable, low cost and scalable devices. Methylammonium lead trihalide perovskite has attracted intense interest due to its high photovoltaic performance, low cost, and ease of manufacture. Their high absorption coefficient, tunable bandgap, low-temperature processing, and abundant elemental constituent provide innumerable advantages over other thin film absorber materials. Since the perovskite film is the most important in the device, morphology, crystallization, compositional and interface engineering have been explored to boost its performance and stability. High temperatures necessary for crystallization of organic-inorganic hybrid perovskite films …

The Hybridization Of A Graphene And Silicon Carbide Schottky Optoelectronic Device By The Incorporation Of A Lead Sulfide Quantum Dot Film, Joshua Letton

Theses and Dissertations

The work that follows examines the impact of lead sulfide quantum dots on a native epitaxial graphene (EG) SiC Schottky device, resulting in a hybrid optoelectronic device which presents a possible avenue towards a novel hybrid carbide-based Schottky solar cell. The active (n-type SiC) and contact (graphene) layers for the Schottky junction of the device were grown epitaxially using a novel technique incorporating tetrafluorosilane (TFS) as a precursor gas. The bare EG/SiC device was characterized based on its I-V behavior in dark and under illumination for both forward and reverse bias conditions. The initial characterization demonstrated the expected Schottky diode …

Monte Carlo Tree Search Applied To A Modified Pursuit/Evasion Scotland Yard Game With Rendezvous Spaceflight Operation Applications, Joshua A. Daughtery

Theses and Dissertations

This thesis takes the Scotland Yard board game and modifies its rules to mimic important aspects of space in order to facilitate the creation of artificial intelligence for space asset pursuit/evasion scenarios. Space has become a physical warfighting domain. To combat threats, an understanding of the tactics, techniques, and procedures must be captured and studied. Games and simulations are effective tools to capture data lacking historical context. Artificial intelligence and machine learning models can use simulations to develop proper defensive and offensive tactics, techniques, and procedures capable of protecting systems against potential threats. Monte Carlo Tree Search is a bandit-based …

Characterization And Sensitivity Analysis Of 6 Meter Cassegrain Antenna, James L. Harris

Theses and Dissertations

This paper will characterize a 6 meter in diameter cassegrain antenna. The cassegrain antenna is a special form of a dual reflector antenna which uses a main reflector following a parabolic curve and a sub reflector which follows a hyperbolic curve. Cassegrain style antennas have multiple parameters which can be tuned to achieve specific design goals. Performing a sensitivity analysis will establish relationships between design parameters, directivity, side lobe levels, and effects of strut geometry. The initial design parameters will be assumed based on typical values. Results from the sensitivity analysis will be used to provide a performance band for …

A Non-Destructive Evaluation Application Using Software Defined Radios And Bandwidth Expansion, Nicholas J. O'Brien

Theses and Dissertations

The development of low-complexity, lightweight and low-cost Non-Destructive Evaluation (NDE) equipment for microwave device testing is desirable from a maintenance efficiency and operational availability perspective. Current NDE equipment tends to be custom-designed, cumbersome and expensive. Software Defined Radio (SDR) technology, and a bandwidth expansion technique that exploits a priori transmit signal knowledge and auto-correlation provides a solution. This research investigated the reconstruction of simultaneous SDR receiver instantaneous bandwidth (sub-band) collections using single, dual and multiple SDR receivers. The adjacent sub-bands, collectively spanning a transmit signal bandwidth were auto-correlated with a replica transmit signal to restore frequency and phase offsets. The …

Near Real-Time Zigbee Device Discrimination Using Cb-Dna Features, Yousuke Z. Matsui

Theses and Dissertations

Currently, Low-Rate Wireless Personal Area Networks (LR-WPAN) based on the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard are at risk due to open-source tools which allow bad actors to exploit unauthorized network access through various cyberattacks by falsifying bit-level credentials. This research investigates implementing a Radio Frequency (RF) air monitor to perform Near RealTime (NRT) discrimination of Zigbee devices using the IEEE 802.15.4 standard. The air monitor employed a Multiple Discriminant Analysis/Euclidean Distance classifier to discriminate Zigbee devices based upon Constellation-Based Distinct Native Attribute (CB-DNA) fingerprints. Through the use of CB-DNA fingerprints, Physical Layer (PHY) characteristics unique to …

Development Of A Drone-Mounted Wireless Attack Platform, Nathan V. Barker

Theses and Dissertations

The commercial drone market has grown rapidly due to the increasing utility and capabilities of drones. This new found popularity has made it possible for inexpensive drones capable of impressive carry capacities and flight times to reach the consumer market. These new features also offer an invaluable resource to wireless hackers. Capitalizing on their mobility, a wireless hacker can equip a drone with hacking tools to surpass physical security (e.g. fences) with relative ease and reach wireless networks. This research seeks to experimentally evaluate the ability of a drone-mounted wireless attack platform equipped with a directional antenna to conduct wireless …

Improved Ground-Based Monocular Visual Odometry Estimation Using Inertially-Aided Convolutional Neural Networks, Josiah D. Watson

Theses and Dissertations

While Convolutional Neural Networks (CNNs) can estimate frame-to-frame (F2F) motion even with monocular images, additional inputs can improve Visual Odometry (VO) predictions. In this thesis, a FlowNetS-based [1] CNN architecture estimates VO using sequential images from the KITTI Odometry dataset [2]. For each of three output types (full six degrees of freedom (6-DoF), Cartesian translation, and transitional scale), a baseline network with only image pair input is compared with a nearly identical architecture that is also given an additional rotation estimate such as from an Inertial Navigation System (INS). The inertially-aided networks show an order of magnitude improvement over the …

Adaptive-Hybrid Redundancy For Radiation Hardening, Nicolas S. Hamilton

Theses and Dissertations

An Adaptive-Hybrid Redundancy (AHR) mitigation strategy is proposed to mitigate the effects of Single Event Upset (SEU) and Single Event Transient (SET) radiation effects. AHR is adaptive because it switches between Triple Modular Redundancy (TMR) and Temporal Software Redundancy (TSR). AHR is hybrid because it uses hardware and software redundancy. AHR is demonstrated to run faster than TSR and use less energy than TMR. Furthermore, AHR allows space vehicle designers, mission planners, and operators the flexibility to determine how much time is spent in TMR and TSR. TMR mode provides faster processing at the expense of greater energy usage. TSR …

Straintronic Nanomagnetic Devices For Non-Boolean Computing, Md Ahsanul Abeed

Theses and Dissertations

Nanomagnetic devices have been projected as an alternative to transistor-based switching devices due to their non-volatility and potentially superior energy-efficiency. The energy efficiency is enhanced by the use of straintronics which involves the application of a voltage to a piezoelectric layer to generate a strain which is ultimately transferred to an elastically coupled magnetostrictive nanomaget, causing magnetization rotation. The low energy dissipation and non-volatility characteristics make straintronic nanomagnets very attractive for both Boolean and non-Boolean computing applications. There was relatively little research on straintronic switching in devices built with real nanomagnets that invariably have defects and imperfections, or their adaptation …

Energy Efficient Spintronic Device For Neuromorphic Computation, Md Ali Azam

Theses and Dissertations

Future computing will require significant development in new computing device paradigms. This is motivated by CMOS devices reaching their technological limits, the need for non-Von Neumann architectures as well as the energy constraints of wearable technologies and embedded processors. The first device proposal, an energy-efficient voltage-controlled domain wall device for implementing an artificial neuron and synapse is analyzed using micromagnetic modeling. By controlling the domain wall motion utilizing spin transfer or spin orbit torques in association with voltage generated strain control of perpendicular magnetic anisotropy in the presence of Dzyaloshinskii-Moriya interaction (DMI), different positions of the domain wall are realized …

Electric Load Forecasting Using Long Short-Term Memory Algorithm, Tianshu Yang

Theses and Dissertations

Abstract

Power system load forecasting refers to the study or uses a mathematical method to process

past and future loads systematically, taking into account important system operating

characteristics, capacity expansion decisions, natural conditions, and social impacts, to

meet specific accuracy requirements. Dependence of this, determine the load value at a

specific moment in the future. Improving the level of load forecasting technology is

conducive to the planned power management, which is conducive to rationally arranging

the grid operation mode and unit maintenance plan, and is conducive to formulating

reasonable power supply construction plans and facilitating power improvement, and

improve the …

Big Data And Sensor Network For Construction Material Testing, Yao Shi

Theses and Dissertations

Engineers and contractors need to have a precise understanding of the development progress of concrete strength in the natural environment, which helps to save project time and cost. However, current practice of concrete construction depends on published data, charts and curves from laboratory tests. The data would not show frequently changing environmental conditions in the real world, which can affect concrete quality significantly. The objective of this research is to design a reliable and accurate method to validate test data of the strength developments of concrete specimens in early stages. The approach includes the following tasks: (1) arrange sensors to …

Ku-Band Ag Channel Modeling, Albert Smith

Theses and Dissertations

With the rise in use of Unmanned Aerial Systems (UAS), there is a need for safe and reliable integration into existing infrastructure. A proposed system for beyond line of sight control links for UAS is a Ku-band air-to-satellite communication system. To ensure this proposed system does not interfere with existing terrestrial infrastructure that operates in the Ku band, an examination of the Ku-band air-to-ground channel is required. The focus of this thesis is the modeling of the Ku-band AG channel. Tests consisting of transmitting a single tone continuous wave signal were conducted with a signal generator onboard NASA’s Viking S-3 …

Non-Destructive Characterization Of Rotated Uniaxial Anisotropic Materials, Alexander G. Knisely

Theses and Dissertations

Electromagnetic material characterization of anisotropic media requires measurement diversity, minimal measurement uncertainty and insight into sample symmetry. Additionally, non-destructive characterization techniques are valued over legacy measurement techniques because a destructive approach requires sample preparation to execute a measurement. A Single Port Waveguide Probe (SPWP) non-destructive material characterization technique is proposed to accommodate measuring a metal backed, known thickness, rotated uniaxial anisotropic material. A rotated uniaxial sample possesses unique transverse constitutive components and a longitudinal constitutive component which is the same as one of the transverse values. The SPWP consists of a rectangular waveguide aperture cut in the center of a …

Segmented Control Of Electrostatically Actuated Bimorph Micromirrors, Kullen W. Waggoner

Theses and Dissertations

Electrostatic actuating bimorph beams are a MEMS device that can be used to control arrays of small micromirrors for optical beam scanning. Previous research has demonstrated that creating high-angle deflection using long repeating arms of bimorph beams is possible. The current devices lack precise control and measurement of the mirror deflection. A solution to improve control and measurement is by using segmented bias channels to control separate portions of the actuation arm. The amount of mirror deflection will vary depending on which segments of the arm are actuated. This thesis discusses the results of FEA modeling and testing.

A Rectenna For 5g Energy Harvesting, Panagiotis Efthymakis

Theses and Dissertations

This thesis describes the design of a rectenna that is capable of operating in 5G. 5G’s availability will create the opportunity to harvest energy everywhere in the network’s coverage. This thesis investigates a Rectenna device with a new proposed topology in order to eliminate coupling between input and output lines and increase the rectification efficiency. Moreover, it is designed to charge a rechargeable battery of 3V, 1mA, with a 4.8mm diameter. The current design describes using one antenna for energy harvesting; this could be expanded to use an antenna array, which would increase the input power. This would lead to …

Novel Wideband Ebg Structures For Isolation Improvement Between Cosite Antennas, Paul John Czeresko Iii

Theses and Dissertations

As the number of installed antennas increases on a structure, the available real estate to do so without each antenna interfering with the others diminishes. Electromagnetic band gap (EBG) structures are one way to mitigate this cosite interference with compact antenna installations. While a host of EBG structures and types (3-D, planar etc.) have been proposed and studied historically, it has been found that planar EBG structures tend to provide very narrow bandwidths for both antenna design and cosite interference reduction. This research focuses on the design of EBG structures intended to achieve greater than 20 dB of isolation improvement …

Engineered Surfaces To Control Secondary Electron Yield For Multipactor Suppression, James M. Sattler

Theses and Dissertations

A significant problem for satellites, vacuum electron devices, and particle accelerators is multipactor: an avalanche of electrons caused by recurring secondary electron emission (SEE) in a time-varying electric field. The consequences of multipactor range from temporary to permanent device failure. This research studied how surface topography can be engineered to minimize SEE and suppress multipactor. Two new semi-empirical models (one based on a 2D pore, the other based on a 3D pore) were developed to predict the secondary electron yield (SEY) of a porous surface based on pore aspect ratio and porosity. The models were validated with experimental SEY measurements …

Improved N-Type 4h-Sic Epitaxial Layer Radiation Detectors And Noise Analysis Of Front-End Readout Electronics, Khai V. Nguyen

Theses and Dissertations

Schottky barrier radiation detectors were fabricated on n-type 4H-SiC epitaxial layers (12 – 50 μm) grown by hot wall CVD process on highly nitrogen doped 4H-SiC (0001) substrates with 4-8º off-cut towards the ̅ direction. Ni/4H-SiC Schottky barrier radiation detectors, a very low leakage current of 0.18 nA at 250 V bias, revealing low thermal noise, was observed in current-voltage (I-V) measurements. Using a thermionic emission model, junction properties such as barrier height of ≥1.10 eV and an ideality factor of ≤1.29 were determined. An effective carrier concentration of 1.03×1015 cm-3 was calculated by capacitance-voltage (C-V) measurement. Deep level transient …

Omni-Directional Infrared 3d Reconstruction And Tracking Of Human Targets, Emrah Benli

Theses and Dissertations

Omni-directional (O-D) infrared (IR) vision is an effective capability for mobile systems in robotics, due to its advantages: illumination invariance, wide field-of-view, ease of identifying heat-emitting objects, and long term tracking without interruption. Unfortunately, O-D IR sensors have low resolution, low frame rates, high cost, sensor noise, and an increase in tracking time. In order to overcome these disadvantages, we propose an autonomous system application in indoor scenarios including 1) Dynamic 3D Reconstruction (D3DR) of the target view in real time images, 2) Human Behavior-based Target Tracking from O-D thermal images, 3) Thermal Multisensor Fusion (TMF), and 4) Visual Perception …

Optical Spectroscopy Of Wide Bandgap Semiconductor Heterostructures And Group-Iv Alloy Quantum Dots, Tanner A. Nakagawara

Theses and Dissertations

Efficient and robust blue InGaN multiple quantum well (MQW) light emitters have become ubiquitous; however, they still have unattained theoretical potential. It is widely accepted that “localization” of carriers due to indium fluctuations theoretically enhance their efficiency by moderating defect-associated nonradiative recombination. To help develop a complete understanding of localization effects on carrier dynamics, this thesis explores degree of localization in InGaN MQWs and its dependence on well thickness and number of wells, through temperature and power dependent photoluminescence measurements. Additionally, silicon-compatible, nontoxic, colloidally synthesizable 2-5 nm Ge_1-xSn_x alloy quantum-dots (QDs) are explored for potential visible to …

Behavioral Responses Of Sub-Adult Atlantic Sturgeon (Acipenser Oxyrinchus Oxyrinchus) To Electromagnetic And Magnetic Fields Under Laboratory Conditions, Andrew Mcintyre Iii

Theses and Dissertations

Electromagnetic fields (EMF) produced by high voltage (HV), submarine transmission cables leading from offshore wind energy generation facilities could affect foraging or migratory behaviors of electro-receptive fishes, including endangered Atlantic Sturgeon. However, no published studies have quantitatively evaluated the possible behavioral effects of EMF exposure on sturgeon during residence in coastal waters. This study evaluated behavioral responses by sub-adult Atlantic Sturgeon to electromagnetic and magnetic fields under controlled laboratory conditions. Fabricated EMF generators were used to emulate a range of field EMF conditions that migratory fishes could encounter in proximity to submarine HV sources. Sensor arrays and digital video recorders …