Engineering Commons^™

Millimeterwave And Mimo Antenna Beamforming For Next-Generationwireless Communications, Ahmed Nadhim Mohammed

Theses and Dissertations

Millimeter wave (mmWave) hybrid precoding systems are likely to have large antenna arrays to overcome the high channel path loss. In such circumstances, low cost hardware and power consumption are the main challenges. Furthermore, the hardware is tasked with computation of high dimensional optimal matrices of hybrid precoding design using Orthogonal Matching Pursuit (OMP). This dissertation addresses two algorithms to enhance the efficiency of the OMP reconstruction algorithm in mmWave precoding design. The spectral efficiency of the mmWave system using the proposed algorithms is compared with previous works and the optimal case (a fully digital precoder). The results show that …

Infrared Electric Field Enhancement Via A Hyperbolic-Metalens-Coupled Nanoantenna, Mohamed Jebril Kyamo

Theses and Dissertations

The development of near- and mid-infrared applications requires high enhancement of the electric field intensity (EFI) and a high absorption cross-section of the electric field. The high enhancement of EFI can be obtained by concentrating optical energy to areas much smaller than the diffraction limit or by using surface plasmon polaritons (SPPs). Noble metals such as gold (Au) or silver (Ag) are not feasible for infrared (IR) applications because of high losses, lack of tunability, low resolution, and low-intensity enhancement. Our methods to solve these problems are based on appropriate metamaterial selection and on coupling systems with optimization of their …

Tribological Characterization Of Nickel-Based Cold Spray Coatings For Aerospace And Industrial Manufacturing, Albert Alejandro

Theses and Dissertations

Cold Spray Additive Manufacturing (CSAM) is a sub-category of thermal spray technology where a metal powder is accelerated in a gas stream toward a metal substrate at high velocities, producing a metallurgical bond with the metal substrate on impact. The present study investigates the effect of Al2O3 additions on the tribological properties of nickel-based cold spray coatings deposited on aluminum 6061 for aerospace and industrial manufacturing. The tribological performance of the nickel-based cold spray coatings with and without Al2O3 additions was evaluated using an abrasive wear test based on the ball-crater technique. In addition, the wear and friction characteristics of …

Non-Negative Discriminative Data Analytics, Md Imrul Kaish

Theses and Dissertations

Due to advancements in data acquisition techniques, collecting datasets representing samples from multi-views has become more common recently (Jia et al. 2019). For instance, in genomics, a lymphoma patient’s dataset may include data on gene expression, single nucleotide polymorphism (SNP), and array Comparative genomic hybridization (aCGH) measurements. Learning from multiple views about the same objective, in general, obtains a better understanding of the hidden patterns of the data compared to learning from a single view data. Most of the existing multi-view learning techniques such as canonical correlation analysis (Hotelling et al. 1936) and multi-view support vector machine (Farquhar et …

Image Processing Algorithms For Detection Of Anomalies In Orthopedic Surgery Implants, Alexander William Wiese

Theses and Dissertations

Orthopedic implant procedures for hip implants are performed on 300,000 patients annually in the United States, with 22.3 million procedures worldwide. While most such operations are successfully performed to relieve pain and restore joint function for the duration of the patient's life, advances in medicine have enabled patients to outlive the life of their implant, increasing the likelihood of implant failure. There is significant advantage to the patient, the surgeon, and the medical community in early detection of implant failures.The research work presented in this thesis demonstrates a non-invasive digital image processing technique for the automated detection of specific arthroplasty …

Epitaxial 4h-Sic Radiation Detectors For Harsh Environment Applications, Joshua W. Kleppinger

Theses and Dissertations

Epitaxial 4H-silicon carbide (4H-SiC) is an essential semiconductor material for the development of harsh environment radiation detectors due to its excellent electrical and thermal properties and resistance to radiation damage, opening the door for a wide variety of applications in NASA space missions, nuclear safeguards, and nuclear energy. However, the low atomic numbers of its constituent atoms Si (Z = 14) and C (Z = 6) make 4H-SiC nearly transparent to most neutrally charged radiation which can only be compensated using thicker active volumes.

In this dissertation, Ni/n-4H-SiC Schottky barrier diode (SBD) radiation detectors are fabricated for the first time …

Growth, Characterization And Evaluation Of Cdzntese Single Crystals For Room Temperature Radiation Detectors, Ritwik Nag

Theses and Dissertations

In this research work Cd_0.9Zn_0.1Te_0.03Se_0.97 (CZTS) single crystals were grown using in-house zone refined 7N (99.99999%) purity elements through vertical Bridgman (VBM) method and vertical gradient freeze (VGF) method. The morphological, compositional, and structural characteristics were then performed on the grown CZTS crystals. The x-ray diffraction (XRD) analysis on the grown crystals showed sharp diffraction peaks indicating a highly crystalline nature, with a lattice constant of ~6.45 Å. The elemental and stoichiometric ratio of the grown CZTS crystals were examined by using energy-dispersive x-ray analysis (EDX), which confirmed the formation of the quaternary …

Magnetic Anomaly Absolute Positioning For Hypersonic Aircraft, Alexander J. Mcneil

Theses and Dissertations

GPS has proven to be an extremely valuable asset for navigation, and timing. GPS has become the standard navigation system for all applications, but GPS has limitations. GPS is susceptible to jamming, spoofing, and in the case of hypersonic aircraft, is likely unavailable. When an aircraft is traveling at hypersonic speeds, there is a plasma sheath that surrounds the aircraft. This plasma sheath blocks electromagnetic waves, and is therefore responsible for a GPS blackout. GPS unavailability for hypersonic aircraft has prompted the research into the viability of alternate navigation systems for these aircraft. This paper seeks to explore the viability …

Detection And Identification Of Cellphone Emitted Light Detection And Ranging Light In Security Camera Video Footage, Tristan V. Creek

Theses and Dissertations

The prevalence of Light Detection and Ranging (LiDAR) sensors in consumer cellphones has ushered in an era of access to technologies previously inaccessible to the average person. Although LiDAR sensors emit light in the infrared spectrum invisible to the naked eye, many security cameras possess the ability to capture infrared light reflected off surfaces to detect LiDAR light in an environment. Once detected and recorded to video footage, current classification methods fail to identify the LiDAR light. Therefore, this research develops a methodology to detect LiDAR light in security camera video footage and identify it as cellphone LiDAR. A proposed …

Utilization Of Characteristic Modal Analysis For Antenna Design Needed For An Afit Satellite, Scott C. Podlogar

Theses and Dissertations

Antenna design is a pervasive, growing field for electrical engineers. As the number of new materials and techniques increase so too does the demand and requirements pushing forth new innovative ideas. Among these ideas is a leading edge analytic technique called Characteristic Modal Analysis (CMA) originally credited to Garbacz and Turpin. CMA works to break down the current distribution along a structure in a way that can offer great insights into how that structure operates as an antenna. This technique has great merits in post design analytics but it is rarely seen to be integrated into the design process. This …

Uav Positioning Data Determined Via Aruco Tags For Aircraft Surface Inspection, Caleb B. Schmidt

Theses and Dissertations

Aircraft are frequently inspected to ensure that military and civilian safety standards are adhered to. These inspections are performed pre- and post-flight and are currently performed by trained maintenance personnel. This work furthers the automation of aircraft surface inspection by using ArUco tags to determine the position of the UAV during aerial inspections. The ArUco tag based position data was then compared to a highly accurate infrared motion capture system to determine the viability of this for accurate positioning of the vehicle. This work includes flight experiments with two different UAVs to perform a system viability comparison.

Monocular Camera Localization Using A Bag Of Visual Words From Virtual World Data, Joshua A. Rinaldi

Theses and Dissertations

The Visual Localization problem is the question of how to use visual information to determine the location of the camera that captured that data. The wide availability and low price of RGB cameras has made this useful in many fields such as SLAM, SAM and AR. This research seeks to determine if a BOVW can adequately overcome repetitious features in indoor environments and be effectively incorporated into a VL pipeline.

Magnetic Flux Channel Antenna Design In Conformal Applications, William J. Tremblay

Theses and Dissertations

Magnetic Flux Channels (MFC) and Magneto-Dielectric Wire Antennas (MDWA) are effective, and in some cases, superior alternatives to traditional metallic antennas, in conformal and electrically small applications at the cost of fabrication and feed complexity. The frequency dispersive nature of magnetic material constituent parameters imposes constraints on the antenna design process, which were not fully developed in prior art. This research quantifies the key differences between the operating regions of magneto-dielectric materials for antenna applications and demonstrates the effectiveness of numerical method augmented modal analysis in the design process, regardless of operating region. Modeling challenges associated with MDWAs are addressed …

Performance Assessment Of Navigation Using Carrier Doppler Measurements From Multiple Leo Constellations, Michael J. Hartnett

Theses and Dissertations

The goal of this work is to characterize a novel navigation method which uses carrier Doppler shift measurements from LEO satellites. An ever-growing reliance on the GNSS has coincided with an increase in ways it can be degraded or denied, whether naturally occurring or man-made. These potentially disastrous threats to traditional navigation and timing have necessitated new technologies to augment GNSS in the case of an outage. LEO constellations, whose size and higher signal power make them potentially useful for navigation, are one technology that has been explored. The navigation algorithms detailed in this research use Doppler measurements from 8 …

Testbed Creation To Study Noise Radar Network Weighting Models And Data Fusion With Radio Tomographic Imaging, Ryan M. Jans

Theses and Dissertations

Significant research has been conducted on RTI weighting models; however, very little comparative research has been conducted for NRN weighting methods. In order to create comparative weighting methods for NRN, it is necessary to create a testbed which allows for RTI and NRN research to be conducted simultaneously and allow for data fusion methods to also be researched. After creating the testbed and analyzing results, the newly proposed weighting method provides an up to 33% performance increase in target localization accuracy when compared to the previous weighting model used for NRN. The attenuation image resolution improvements resulted in a 79% …

Malware Detection Using Electromagnetic Side-Channel Analysis, Matthew A. Bergstedt

Theses and Dissertations

Many physical systems control or monitor important applications without the capacity to monitor for malware using on-device resources. Thus, it becomes valuable to explore malware detection methods for these systems utilizing external or off-device resources. This research investigates the viability of employing EM SCA to determine whether a performed operation is normal or malicious. A Raspberry Pi 3 was set up as a simulated motor controller with code paths for a normal or malicious operation. While the normal path only calculated the motor speed before updating the motor, the malicious path added a line of code to modify the calculated …

Applications Of A Lightning Proxy To Generate Synthetic Lightning For Use In Physics-Based Image-Chain Models, Bryan G. Castro

Theses and Dissertations

A method of generating synthetic lightning through the use of a convective available potential energy (CAPE) times precipitation rate (P) proxy is applied over three distinct climatological zones of the world for a single warm season: central and southern AZ of the United States, central Cuba, and North Korea. Global Forecast System (GFS) 0.25° by 0.25° forecast data for June, July, and August of 2019 is used to provide 6-hourly CAPE and precipitation rate, while Global Lightning Dataset (GLD360) data for the period 2016 to 2020 is used to provide observed lightning strokes. A five-year lightning climatology study is conducted …

Deep Learning Techniques To Estimate 3d Position In Stereoscopic Imagery, Jonathan I. Nicholson

Theses and Dissertations

Current AAR efforts utilize machine vision algorithms to estimate the pose of a receiver aircraft. However, these algorithms are dependent on several conditions such as the availability of precise 3D aircraft models; the accuracy of the pipeline significantly degrades in the absence of high-quality information given beforehand. We propose a deep learning architecture that estimates the 3D position of an object based on stereoscopic imagery. We investigate the use of both machine learning techniques and neural networks to directly regress the 3D position of the receiver aircraft. We present a new position estimation framework that is based on the differences …

Relative Magnetic Position And Rotation Sensor Assisted Dual-Foot Pedestrian Dead Reckoning, Jenario Y. Johnson

Theses and Dissertations

The use of wearable foot-based inertial measurement units (IMUs) incorporated in a navigation system can address the problem of single-person location tracking in situations and environments where GPS signals may be unavailable or inconsistent. This Pedestrian Dead Reckoning (PDR) approach enables standalone personal tracking. A notable solution involves using inertial measurement units (IMUs) in a filter to apply zero-velocity updates to a Kalman filter to get a position solution. This paper continues on the path of the former method by investigating the feasibility of PDR using a pair of low cost IMUs along with a pair of relative position and …

Considering Dds In The Domain Of Dis - Pros And Cons, Nathaniel R. Peck

Theses and Dissertations

DIS is a legacy IEEE standard for defining and structuring PDUs in large scale distributed wargames. Although the standard specifies various QoS appropriate for certain PDUs, a one-size-fits-all transport strategy is traditionally employed via UDP. Since the inception of DIS, the OMG has produced a standard for a DDS which has been implemented by several middleware vendors. DDS middleware offers an abstraction for network communications that allows applications and developers to easily employ configurable QoS by topic. Adoption and use of these QoS in DIS applications may introduce greater compliance with the IEEE standard and enrich the service features available …

Evaluation Of The Armas-Som Framework With Real Data, Brandon M. Blakely

Theses and Dissertations

The ARMAS framework was created with the goal of developing a framework for all-source sensors which is able to combine detection, identification, calibration, model selection, and independent evaluation into a single system. Stable Observability Monitoring (SOM), augments the original ARMAS framework by enabling ARMAS to detect whether or not its Fault Detection and Exclusion (FDE) capabilities can be trusted and when additional sensor information is required to maintain resiliency. While previously tested with simulated sensor data, SOM has yet to be tested with real-life sensor data. Furthermore, ARMAS has only been tested with real-life GNSS data. This work expands on …

Global Sporadic-E Climatological Analysis Using Gps Radio Occultation And Ionosonde Data, Travis J. Hodos

Theses and Dissertations

A climatology of sporadic-E (Es) derived from a combined data set of GPS radio occultation (GPS-RO) and ground-based ionosonde soundings is presented for the period from September 2006 to February 2019. The ionosonde soundings were measured using the Lowell Digisonde International (LDI) Global Ionosphere Radio Observatory (GIRO) network consisting of 65 sites and 13,141,060 total soundings. The GPS-RO observations were taken aboard the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites and processed using two binary Es detection algorithms, totaling 9,072,922 occultations. The first algorithm is an S4 amplitude threshold calibrated to the occurrence of any blanketing Es …

Design Study For An Antenna Radar Cross Section Measurement Test Fixture, Wayne C. Kreimeyer

Theses and Dissertations

Military technology requires equipment to be undetected by adversaries. Stealth aircraft are designed to be undetected through electromagnetic means by minimizing a return signature called the RCS. Therefore, it is essential to understand how antennas, which are necessary for communication, affect the overall RCS of the aircraft. The antenna is measured in a compact RADAR range. The antenna needs a structure to support it, also referred to as a test fixture, that does not interfere with the measuring process of the antenna’s RCS. This thesis set out to get the lowest RCS possible of a test fixture by evaluating different …

Single Event Transient Sensitivity Measurement And Worst-Case Test Vector Exploration For Asic Devices Exposed To Space Single Event Environment, Mohamed Wael

Theses and Dissertations

Space radiation and nuclear reactors produce single event effects (SEE) in electronic circuits and impact their performance. The SEE phenomena cause circuits and electronic devices to fail by producing faulty results. Therefore, today’s circuit’s reliability is a significant concern for all circuit designers.

This thesis suggests a new automated flow to measure the single-event-transient (SET) effects in combinational circuits in application-specific integrated circuits (ASIC) while reaching full fault coverage. The developed flow characterizes the whole circuit nodes by identifying the most sensitive paths to the propagated SET pulses from the node under test to an observable primary output, causing single …

Artificial Intelligence-Powered Chronic Wound Management System: Towards Human Digital Twins, Salih Sarp

Theses and Dissertations

Artificial Intelligence (AI) has witnessed increased application and widespread adoption over the past decade. AI applications to medical images have the potential to assist caregivers in deciding on a proper chronic wound treatment plan by helping them to understand wound and tissue classification and border segmentation, as well as visual image synthesis.

This dissertation explores chronic wound management using AI methods, such as Generative Adversarial Networks (GAN) and Explainable AI (XAI) techniques. The wound images are collected, grouped, and processed. One primary objective of this research is to develop a series of AI models, not only to present the potential …

Learning Robot Motion From Creative Human Demonstration, Charles C. Dietzel

Theses and Dissertations

This thesis presents a learning from demonstration framework that enables a robot to learn and perform creative motions from human demonstrations in real-time. In order to satisfy all of the functional requirements for the framework, the developed technique is comprised of two modular components, which integrate together to provide the desired functionality. The first component, called Dancing from Demonstration (DfD), is a kinesthetic learning from demonstration technique. This technique is capable of playing back newly learned motions in real-time, as well as combining multiple learned motions together in a configurable way, either to reduce trajectory error or to generate entirely …

Smart City Management Using Machine Learning Techniques, Mostafa Zaman

Theses and Dissertations

In response to the growing urban population, "smart cities" are designed to improve people's quality of life by implementing cutting-edge technologies. The concept of a "smart city" refers to an effort to enhance a city's residents' economic and environmental well-being via implementing a centralized management system. With the use of sensors and actuators, smart cities can collect massive amounts of data, which can improve people's quality of life and design cities' services. Although smart cities contain vast amounts of data, only a percentage is used due to the noise and variety of the data sources. Information and communication technology (ICT) …

Low Loss Plasmon-Assisted Integrated Photonics, Dhruv Fomra

Theses and Dissertations

Photonic integrated circuits (PICs), semiconductor chips with both photonic and electronic elements, are seeing rapid development and have the potential to transform several industries, such as autonomous driving, computing, telecommunication and quantum networks. However, realization and wide adoption of PICs across the various fields faces a key challenge – soze disparity between electronic (~0.01 um) and photonic components (~100’s of um). Plasmonics, a technology which confines light to the interface of metals and dielectrics, has a potential to address challenges. In particular, it has been shown to led to smaller devices (~10 um or less), enabling higher density optical circuits …

Low Insertion-Loss Nanophotonic Modulators Through Epsilon-Near-Zero Material-Based Plasmon-Assisted Approach For Integrated Photonics, Mohammad Ariful Hoque Sojib

Theses and Dissertations

Electro-optic/absorption Modulators (EOM/EAMs) encode high-frequency electrical signals into optical signals. With the requirement of large packing density, device miniaturization is possible by confining light in a sub-wavelength dimension by utilizing the plasmonic phenomenon. In plasmon, energy gets transferred from light to the form of oscillation of free electrons on a surface of a metal at an interface between the metal and a dielectric. Plasmonic provides increased light-matter interaction (LMI) and thus making the light more sensitive to local refractive index change. Plasmonic-based integrated nanophotonic modulators, despite their promising features, have one key limiting factor of large Insertion Loss (IL) which …