Engineering Commons^™

Generalizable Deep-Learning-Based Wireless Indoor Localization, Ali Owfi

All Theses

The growing interest in indoor localization has been driven by its wide range of applications in areas such as smart homes, industrial automation, and healthcare. With the increasing reliance on wireless devices for location-based services, accurate estimation of device positions within indoor environments has become crucial. Deep learning approaches have shown promise in leveraging wireless parameters like Channel State Information (CSI) and Received Signal Strength Indicator (RSSI) to achieve precise localization. However, despite their success in achieving high accuracy, these deep learning models suffer from limited generalizability, making them unsuitable for deployment in new or dynamic environments without retraining. To …

Novel Non-Invasive Detection Of Thin Film Biofilm And Classification Of Deposits Using Machine Learning, Sachin Davis

Theses and Dissertations

Clean, safe, readily available water is vital for public health, irrespective of whether it is used for drinking, domestic use, food production, or recreational purposes. Globally, around two billion people use feces-contaminated water sources, which poses a high risk to the safety of drinking water due to the high probability of water contamination. Microbial-influenced corrosion is a significant problem in several industries, including but not limited to wastewater treatment, drinking water distribution systems, food industries, power plants, paper industries, and chemical manufacturing facilities. The presence of microorganisms causes around 70% of the corrosion in gas transmission pipelines, and corrosion accounts …

Reliability Assessment Of Electric Power Systems With Smart Monitoring Using Monte Carlo Simulation, Chia Min Lee

Theses and Dissertations

This thesis proposes a Markov model that combines smart monitoring with electrical components to analyze overall power system reliability. The Markov model accounts for the reliability factors of smart monitoring such as failure rates, fault detection rates, and repair rates to demonstrate the effectiveness of smart monitoring in reducing component failures. The Markov absorbing probability values are derived and used in IEEE RTS 79 to evaluate the impact of integrating smart monitoring on power system reliability. Through Sequential Monte Carlo Simulation, power system reliability indices such as LOLP, EDNS and EENS are calculated. The test cases consist of three scenarios …

A Study Of 5g Cellular Connectivity To Unmanned Aerial Vehicles, Jackson Murrin

All Theses

The market of unmanned aerial vehicles (UAVs) has seen significant growth in the past ten years on both the commercial and military sides. The applications for UAVs are endless and options by manufacturers allow users to modify their drones for their specific goals. This industry has opened up the excitement of piloting vehicles in the air, photography, videography, exploration of nature from a different point of view and many other hobbies assisted by the emergence of UAVs. The growth of this industry coincides with the roll out of new 5G cellular network technology. This upgrade in cellular network infrastructure allows …

Design And Fabrication Of An Optical Blade Tip Timing Sensor, Nick Tomlinson

All Theses

Electricity is a vital energy source that powers modern technology. Turbines are heavily relied on in the electric power industry for the conversion of natural energy sources into electricity. These turbines operate under harsh conditions which increase the likelihood of blade damage. Structural health monitoring of a turbine’s blades is important to detect problems before a blade experiences failure. The blade tip timing method can be used to monitor blade vibrations and determine if damage has occurred. An optical blade tip timing sensor is designed and fabricated to advance the field of sensing in the power industry.

Digital Twins And Artificial Intelligence For Applications In Electric Power Distribution Systems, Deborah George

All Theses

As modern electric power distribution systems (MEPDS) continue to grow in complexity, largely due to the ever-increasing penetration of Distributed Energy Resources (DERs), particularly solar photovoltaics (PVs) at the distribution level, there is a need to facilitate advanced operational and management tasks in the system driven by this complexity, especially in systems with high renewable penetration dependent on complex weather phenomena.

Digital twins (DTs), or virtual replicas of the system and its assets, enhanced with AI paradigms can add enormous value to tasks performed by regulators, distribution system operators and energy market analysts, thereby providing cognition to the system. DTs …

Modeling And Validating Temporal Rules With Semantic Petri Net For Digital Twins, Han Liu, Xiaoyu Song, Ge Gao, Hehua Zhang, Yu-Shen Liu, Ming Gu

Electrical and Computer Engineering Faculty Publications and Presentations

Semantic rule checking on RDFS/OWL data has been widely used in the construction industry. At present, semantic rule checking is mainly performed on static models. There are still challenges in integrating temporal models and semantic models for combined rule checking. In this paper, Semantic Petri-Net (SPN) is proposed as a novel temporal modeling and validating method, which implements the states and transitions of the Colored Petri-Net directly based on RDFS and SPARQL, and realizes two-way sharing of knowledge between domain semantic webs and temporal models in the runtime. Several cases are provided to demonstrate the possible applications in digital twins …

Towards Reliable Hepatocytic Anatomy Segmentation In Laparoscopic Cholecystectomy Using U-Net With Auto-Encoder, Koloud Najem Alkhamaiseh

Dissertations

Despite the advantages of minimally invasive surgeries that depend heavily on vision, the indirect access and lack of the 3D field of view of the area of interest introduce some complications in the desired procedures. Fortunately, the recorded videos from these procedures offer the opportunity for intra-operative and post-operative analyses, to improve future performance and safety.

Deep learning models for surgical video analysis could therefore support visual tasks such as identifying the critical view of safety (CVS) in laparoscopic cholecystectomy (LC), potentially contributing to the reduction of the current rates of bile duct injuries in LC. Most bile duct injuries …

Development Of A Soft Robotic Approach For An Intra-Abdominal Wireless Laparoscopic Camera, Hui Liu

Doctoral Dissertations

In Single-Incision Laparoscopic Surgery (SILS), the Magnetic Anchoring and Guidance System (MAGS) arises as a promising technique to provide larger workspaces and field of vision for the laparoscopes, relief space for other instruments, and require fewer incisions. Inspired by MAGS, many concept designs related to fully insertable magnetically driven laparoscopes are developed and tested on the transabdominal operation. However, ignoring the tissue interaction and insertion procedure, most of the designs adopt rigid structures, which not only damage the patients' tissue with excess stress concentration and sliding motion but also require complicated operation for the insertion. Meanwhile, lacking state tracking of …

A Scalable, Cost-Oriented Approach For Computing Charge Plans For Electric Bus Fleets, Daniel T. Mortensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent attention for reduced carbon emissions has pushed transit authorities to adopt battery electric buses (BEBs). One challenge experienced by BEB users is extended charge times, which create logistical challenges and may force BEBs to charge when energy is more expensive. Furthermore, BEB charging leads to high power demands, which can significantly increase monthly power costs and may push electrical infrastructure beyond its present capacity, requiring expensive upgrades. This work presents a novel method for minimizing the monthly cost of BEB charging while meeting bus route constraints. This method extends previous work by incorporating a more novel cost model, effects …

Characterization, Simulation, And Test Method For Image Artifacts Due To Phase Drift Of The Saw Filter In The Magnetic Resonance Receiver, Gabriel T. Jacobs

Theses and Dissertations

The receiver for a Magnetic Resonance (MR) scanner is responsible for capturing the precise frequency and phase of extremely low-power RF signals emanating from the human body; and consequentially must minimize unexpected phase drift in the received signal. One well-known source for temperature-dependent phase drift in RF electronics is the Surface Acoustic Wave (SAW) filter. In this work, the phase drift due to temperature changes in the SAW filter of an MR receiver was evaluated for its potential effects on image quality using several image quality metrics. A lab bench method was developed to playback MR images using typical lab-equipment …

Embedded Ultrasonic Inspection Of Liquid Filled Pressure Vessels, Trevor Wenzel

Theses and Dissertations

Structural health monitoring and ultrasonic inspection techniques can be used to inspect a structure for degradation. There are several different approaches for doing this including the use of an embedded sensing system which uses elastic wave propagation through the structure. Previous work using this method has explored ultrasonic inspection of a simple, flat plate structure, however, structures often have more complex geometry, and the flat plate offers only a basic understanding of elastic wave propagation. Therefore, experimental approaches and results drive how these techniques can be used for ultrasonic inspection of complex vessels where challenges arise due to the potential …

Tunable Linewidth Chip-Level Lasers Using Hybrid Integration Methods, Charles Porter

All Theses

Photonic integrated circuits (PICs) have significant value in today’s world of research. They enable devices to experience large reductions in size, weight, operation power, and cost (SWAPc), making photonic technology more accessible than ever. The functionality of PICs is greatly enhanced due to the realization of both active and passive devices within a single device structure. This is made possible through hybrid integration, which utilizes various coupling methods to transfer light from an active chip to a passive chip. Hybrid integration technology tremendously expands the capabilities of PICs, leading to a plethora of applications. One significant application is that of …

Augmented Human Inspired Phase Variable Using A Canonical Dynamical System, Timothy Driscoll

All Theses

Accurately parameterizing human gait is highly important in the continued development of assistive robotics, including but not limited to lower limb prostheses and exoskeletons. Previous studies introduce the idea of time-invariant real-time gait parameterization via human-inspired phase variables. The phase represents the location or percent of the gait cycle the user has progressed through. This thesis proposes an alternative approach for determining the gait phase leveraging previous methods and a canonical dynamical system.

Human subject experiments demonstrate the ability to accurately produce a phase variable corresponding to the human gait progression for various walking configurations. Configurations include changes in incline …

Simple Mechanically Reconfigurable Patch Antennas, Luis Alonso Hernandez Galvan

Theses and Dissertations

Reconfigurable antennas form an active subdivision of antenna and communications research primarily targeted at achieving reconfigurability in the RF, microwave, and millimeter-wave frequency regimes. Mechanical, all-electronic, material based, and optical methods are the most common approaches to achieve reconfigurability. Each method can overlap to create new and innovative approaches to enable device tunability. The sub-class of reconfigurable antennas are antennas that dynamically achieve an adaptable transformation of their frequency, radiation-pattern, polarization, and/or bandwidth characteristics to enable multiple dynamic functionalities.

In this thesis, we designed new rectangular and triangular microstrip patch array antennas operating in the 5G midband at 5GHz. These …

Nrc-Sim: A Node-Red Based Multi-Level, Many-Core Cache Simulator, Ezequiel Treviño

Theses and Dissertations

As computational systems become ever-more integral to daily life, so too does the importance of understanding how these complex systems work. For those unfamiliar with the underlying concepts, this can be a daunting task. In an effort to address such concerns, this paper presents a Node-RED based cache simulator that enables users to observe the effects of their desired cache configuration, with users having the ability to easily modify various parameters, such as the core count, the number of levels within the cache, and coherence protocols, among other parameters. Through the use of Node-RED, NRC-SIM allows for simplicity of use …

Integrated Energy-Aware Motion Planning And Charge Scheduling Of Unmanned Aerial Vehicles, Hayleyesus Alemayehu

All Theses

The growing demand for unmanned aerial vehicles (UAVs) is driven by their operational convenience, cost-effectiveness, availability, and adaptability to various scenarios. In energy-constrained environments, optimizing energy consumption and ensuring a continuous power supply for UAVs is crucial for mission success. The objective of this thesis is to address this issue by integrating energy-aware motion planning and charge scheduling for UAVs by utilizing a charger hosted on an unmanned ground vehicle (UGV), whose rendezvous locations and routes are jointly computed to minimize overall energy consumption.

This thesis proposes a hierarchical trajectory and control framework comprising local and global planners for each …

Developing Firmware For Space Weather Probes 2 Using Hdl Coder, Nicholas L. Wallace

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

GPS and wireless communications are affected by interference from the ionosphere. Space weather affects plasma in the ionosphere, causing communication disruptions and reliability issues. To better understand how space weather affects the ionosphere, instruments are flown in space to collect data about the electrical characteristics of plasma in the ionosphere. Space systems require a lot of time and effort to develop and test. This thesis explores how a high level tool can be used to simplify the process and some obstacles that still exist with developing some space systems. To do this, the firmware architecture of a new version of …

Super-Resolution Textured Digital Surface Map (Dsm) Formation By Selecting The Texture From Multiple Perspective Texel Images Taken By A Low-Cost Small Unmanned Aerial Vehicle (Uav), Bikalpa Khatiwada

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Textured Digital Surface Model (TDSM) is a three-dimensional terrain map with texture overlaid on it. Utah State University has developed a texel camera which can capture a 3D image called a texel image. A TDSM can be constructed by combining these multiple texel images, which is much cheaper than the traditional method. The overall goal is to create a TDSM for a larger area that is cheaper and equally accurate as the TDSM created using a high-cost system.

The images obtained from such an inexpensive camera have a lot of errors. To create scientifically accurate TDSM, the error presented in …

Development Of The Digital Signal Processing For The Space Weather Probes Version 2 Sensor Using The Matlab/Simulink Environment, Benjamin J. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Space Weather Probes (SWP) is an instrument that provides measurements of the plasma environment of the ionosphere. SWP was flown on the Scintillation Prediction Observation Task (SPORT) mission, a joint mission between the United States of America and Brazil. This thesis will develop the digital signal processing (DSP) hardware design for the Space Weather Probes version 2 (SWP2). The data from these instruments will be used to determine the density and temperature of the local plasma, as well as the electric field in the local plasma. This thesis presents the design and testing of the DSP designs for all of …

Reclaiming Fault Resilience And Energy Efficiency With Enhanced Performance In Low Power Architectures, Noel Daniel Gundi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid developments of the AI domain has revolutionized the computing industry by the introduction of state-of-art AI architectures. This growth is also accompanied by a massive increase in the power consumption. Near-Theshold Computing (NTC) has emerged as a viable solution by offering significant savings in power consumption paving the way for an energy efficient design paradigm. However, these benefits are accompanied by a deterioration in performance due to the severe process variation and slower transistor switching at Near-Threshold operation. These problems severely restrict the usage of Near-Threshold operation in commercial applications. In this work, a novel AI architecture, Tensor Processing …

Modeling & Small Signal Analysis Of Grid Forming Inverter, Kadesh Hepburn

Graduate Theses and Dissertations

There is a rising number of inverter-based resources (IBRs) being integrated with distribution systems are becoming a more common occurrence. With integration of IBRs inverters, power utilities are experiencing an increase of number of operations with regards to voltage and frequency support. To maintain grid stability and reliability, IBRs need to provide some of the services currently (or formerly) provided by synchronous generators. Interconnection standards, like the IEEE 1547. 2018 has include requirements for IBRs to have the capability to provide some of these services—such as frequency and voltage support—and the procurement and deployment of the services can be implemented …

Fabrication And Measurement Of Lt-Gaas Photoconductive Antennas And Arrays, Zachary Paul Uttley

Graduate Theses and Dissertations

This thesis presents the fabrication and measurement of LT-GaAs based terahertz (THz) photo conductive antennas (PCAs) and arrays. The LT-GaAs THz PCAs are fabricated to serve as reference devices to new 2D material black phosphorous (BP) based THz PCAs. The LT-GaAs and BP devices have identical metallic electrodes, allowing for a comparison of emitted THz intensity and bandwidth. All PCAs have been measured using an open bench pulsed time-domain spectroscopy (TDS) system with a usable bandwidth from 0.1-4 THz, pumped with a 780nm Ti:Sapphire femtosecond laser. The results have shown LT-GaAs devices outperforming BP devices in signal amplitude and bandwidth …

Optocoupler Integration Of Ltcc-Based Gate Driver In A Sic Power Module, Michael Oghenekome Otobo

Graduate Theses and Dissertations

The growing demand for electrical energy in today’s industrialized economy has driven the need for innovative approaches to meet diverse application requirements. Notably, advancements have been made in the field of power electronic systems, as reliable power electronic converters are essential for managing multiple power sources and loads. However, the development of these systems poses challenges related to power device switching speed, system weight and size, and power losses. The integration of a gate driver into a SiC power module offers a solution to many of these challenges, thereby driving the advancement of electrical power density expansion. An LTCC-based gate …

Understanding Peripheral Blood Pressure Signals: A Statistical Learning Approach, Md Abul Hayat

Graduate Theses and Dissertations

Proper estimation of body fluid status for human or animal subjects has always been a challenging problem. Accurate and timely estimate of body fluid can prevent life threatening conditions under trauma and severe dehydration. The main objective of this research is the estimation, classification and detection of dehydration in human and animal subjects using peripheral blood pressure (PBP) signals. Peripheral venous pressure (PVP) and peripheral arterial pressure (PAP) signals have been investigated in this research. Both PVP and PAP signals are PBP signals. A dataset of PVP signals was collected using standard peripheral intravenous catheters from human subjects suffering from …

Achieving High Renewable Energy Integration In Smart Grids With Machine Learning, Yaze Li

Graduate Theses and Dissertations

The integration of high levels of renewable energy into smart grids is crucial for achieving a sustainable and efficient energy infrastructure. However, this integration presents significant technical and operational challenges due to the intermittent nature and inherent uncertainty of renewable energy sources (RES). Therefore, the energy storage system (ESS) has always been bound to renewable energy, and its charge and discharge control has become an important part of the integration. The addition of RES and ESS comes with their complex control, communication, and monitor capabilities, which also makes the grid more vulnerable to attacks, brings new challenges to the cybersecurity. …

Double-Sided Cooled Power Modules For Electric Vehicles, Riya Paul

Graduate Theses and Dissertations

Double-sided cooled (DSC) power modules in conjunction with Silicon Carbide (SiC) power devices are expected to significantly elevate the performance of the next-generation electric vehicle power inverters. The double-sided cooling enables maximum heat dissipation, resulting in higher power density. SiC power devices, with their fast-switching speeds, reduce the power losses for higher efficiency. A half-bridge power module consisting of 13 mΩ 1.2 kV SiC devices is used for this work. A baseline DSC power module was designed, fabricated, and tested. This unique design uses truncated rectangular copper connection blocks for better heat dissipation from the device top side compared to …

An Avalanche Transistor-Based Pulse Generator Design For Infrared Laser Applications, Abraham Lopez

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis details the design and results of a circuit intended for infrared laser applications, specifically for transcranial infrared light simulation (TILS) experiments and for use as a range finder. The circuit itself is comprised of a transistor, high voltage power supply, laser diode, capacitor, resistor, diode, and low voltage pulse. The design of a range finder is also developed. The range finder design is the same as the circuit developed for TILs with the addition of a few more components for receiving the returned light pulse such as a photodiode, op-amp, and comparator. The techniques used for a successful …

Survey Of How Irregularities In The Electrical System Of The Human Heart Link To Different Heart Arrhythmias, Jazmine Boloor

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis explores the circuital pathway that a signal takes within the heart throughout a full heartbeat and provides a timing analysis. It then surveys the different pathways that could arise in the electrical system of the heart, and the associated heart diseases linked to the location of each pathway. Common heart arrhythmias such as atrioventricular nodal reentrant tachycardia, atrioventricular reentrant tachycardia, atrial flutter, and atrial fibrillation are surveyed, and their pathways are analyzed. Electrocardiograms are presented to aid in understanding of the timing analysis associated with irregularity in heart function. Finally, this thesis explores an avenue of the heartbeat …

Towards A Robust Defense: A Multifaceted Approach To The Detection And Mitigation Of Neural Backdoor Attacks Through Feature Space Exploration And Analysis, Liuwan Zhu

Electrical & Computer Engineering Theses & Dissertations

From voice assistants to self-driving vehicles, machine learning(ML), especially deep learning, revolutionizes the way we work and live, through the wide adoption in a broad range of applications. Unfortunately, this widespread use makes deep learning-based systems a desirable target for cyberattacks, such as generating adversarial examples to fool a deep learning system to make wrong decisions. In particular, many recent studies have revealed that attackers can corrupt the training of a deep learning model, e.g., through data poisoning, or distribute a deep learning model they created with “backdoors” planted, e.g., distributed as part of a software library, so that the …