Engineering Commons^™

The Study Of Corrosion On Additive-Manufactured Metals., Braydan Daniels

Electronic Theses and Dissertations

The purpose of this study was to investigate and compare the corrosion mechanisms between wrought and additive-manufactured (3D-printed) copper and stainless steel. The experimental procedure consisted of measuring the open circuit potential, electrochemical impedance spectroscopy, linear sweep voltammetry, Tafel analysis, surface topology, and scanning electron microscopy for each metal within salt water, tap water, sulfuric acid, and synthetic body fluid (excluding copper in synthetic body fluid).

Overall, printed stainless steel was more corrosion-resistant than wrought stainless steel in tap water and synthetic body fluid based on OCP, LSV, and surface topology results. Additionally, printed copper was more corrosion-resistant than wrought …

Measurements Of Magnetic Field Penetration Of Materials For Superconducting Radiofrequency Cavities, Iresha Harshani Senevirathne

Physics Theses & Dissertations

Superconducting Radio Frequency (SRF) cavities used in particle accelerators are typically formed from or coated with superconducting materials. Currently high purity niobium is the material of choice for SRF cavities which have been optimized to operate near their theoretical field limits. This brings about the need for significant R&D efforts to develop next generation superconducting materials which could outperform Nb and keep up with the demands of new accelerator facilities. To achieve high quality factors and accelerating gradients, the cavity material should be able to remain in the superconducting Meissner state under high RF magnetic field without penetration of quantized …

Entropy Aided Rf-Dna Fingerprint Learning From Gabor-Based Images, Mohamed Alfatih Taha

Masters Theses and Doctoral Dissertations

The number of devices connected to the internet have been increasing and shape Internet of Things (IoT). The security of IoT is an issue due to the use of weak or no encryption. Specific Emitter Identification (SEI) was introduced to overcome this issue by introduce RF-DNA fingerprinting exploring the PHY layer features. Recently, The SEI performance improved by the usage of the signal’s Time Frequency (TF) representation and accelerated using the Deep learning (DL) Convolutional Neural Network (CNN). While the classification accuracy has been improved from using raw signals learning the amount of data generated is large and computationally expensive. …

Formation Control Of Multiple Quadrotors, Miguel Alejandro Garcia

Theses and Dissertations

This thesis studies formation control of multiple quadrotors under different conditions. Two controller design approaches are proposed. In the first approach, it is assumed that the dynamics of each quadrotor is unknown and there is disturbance. With the aid of distributed estimation and the universal approximation property of neural networks, distributed tracking controllers are proposed. Simulation shows the effectiveness of the proposed controllers. In the second approach, it is assumed that the inertia parameters are unknown. With the aid of distributed estimation, online data estimation, and optimal control theory, distributed sub-optimal tracking controllers are proposed. Simulation results show the effectiveness …

Graphene-Conductive Ink Coated Laser Engraved Kapton Electrochemical Biosensor For The Detection Of Dopamine And Immune Sensing, Dipannita Ghosh

Theses and Dissertations

Novel and flexible disposable laser-engraved Kapton (LEK) electrodes modified with graphene conductive inks have been developed for dopamine and Interleukin-6 (IL-6) detection. The LEK sensors exhibit high reproducibility (RSD=0.76%, N=5) and stability (RSD=4.39%, N=15)after multiple bendings, and thus make the sensors ideal for wearable and stretchable bioelectronics applications. We have developed graphene conductive ink- PEDOT:PSS (G-PEDOT:PSS) and polyaniline (G-PANI) based electrode coatings for working electrode modification to improve the sensitivity (41.41 times higher for screen printed electrode with G-PEDPT:PSS ink modification),and limit of detection (LOD) . We have further compared the performance of the fabricated electrodes with commercially available screen-printed …

Monitoring Of Ac Motors Parameters Using Industrial Internet Of Things, Mohammad Muheisen

Theses and Dissertations

In this thesis, the industrial internet of things has been introduced, as a very newborn research field. The suggested prototype has been assembled at the university laboratory to simulate the system conditions. Two three-phase induction motors have been utilized to perform this study, to monitor and gather data, regarding vibration and temperature. As a very newborn field, the data collected from the two motors can be analyzed to achieve a couple of goals, in energy consumption, to reduce the financial burden of the remedy works. A fast Fourier transformer has been applied to measure the motor's vibrations, and the current …

Procedural City Generation With Combined Architectures For Real-Time Visualization, Griffin Poyck

All Theses

The work and research of this paper sought to build upon traditional city generation and simulation in creating a tool that both realistically simulates cities and their prominent features and also creates aesthetic and artistically rich cities using assets that combine several contemporary or near contemporary architectural styles. The major city features simulated are the surrounding terrain, road networks, individual buildings, and building placement. The tools used to both create and integrate these features were created in Houdini with Unreal Engine 5 as the intended final destination. This research was influenced by the city, town, and road networking of Ghost …

Characterization Of Piezoelectric Coefficient Using Combined Optical And Electrical Methods, Limna Sainudeen Attoor

Theses

The characterization of piezoelectric coefficients, specifically, the extraction of D33 charge constant versus applied voltage profiles plays an important role in MEMS (Micro Electro Mechanical Systems) design and actuation. MEMS structures widely use piezoelectric thin films due to their advantages of possessing high piezoelectric constants and lightweight properties. Hence there is a need for characterizing piezoelectric materials so that one can predict their response during different operating conditions. In this work, a combined electrical and light-based methodology to characterize the voltage dependency profile of d33 is developed. A set of equations are extracted based on the electrical capacitance and light …

Evaluation Of Human Mobility From Crowd-Sourced Cellular Data, Sasa Knezevic

Theses and Dissertations

Understanding patterns of human mobility plays a vital role in urban planning, traffic management, disease control, environmental impact evaluation, provisioning of services by both public and private enterprise and other areas of human activity. In this thesis, the human mobility patterns are studied using crowd sourced cellular data. The study characterizes human mobility through a meaningful set of mobility parameters. Each parameter is clearly defined, extracted from the available data, and described using statistical modeling tools. The parameters are evaluated at different time scales. It has been determined that despite its apparent randomness on the individual level, human mobility on …

Effect On Focusing Fields By Ferromagnetic Cell Cores In Linear Induction Accelerators, Cooper Guillaume

Senior Honors Theses

In the Los Alamos National Laboratories DARHT facility, there are two perpendicular linear induction accelerators, LIAs. The LIAs’ solenoids produce magnetic fields which focus the electron beam. Simultaneously, the accelerating pulse creates a magnetic field. These two field intensities act upon a ferromagnetic material in the cells to enhance magnetic flux density. Due to the nonlinearity of the material, this flux density will reach a saturation point. In turn, the magnetic field intensity of the axial solenoidal magnetic field will be affected and slightly altered. The width of the electron beam will increase, causing a decrease in effectiveness. Through simulation, …

Rattus Norvegicus As A Biological Detector Of Clandestine Remains And The Use Of Ultrasonic Vocalizations As A Locating Mechanism, Gabrielle M. Johnston

Master's Theses

In investigations, locating missing persons and clandestine remains are imperative. One way that first responder and police agencies can search for the remains is by using cadaver dogs as biological detectors. Cadaver dogs are typically used due to their olfactory sensitivity and ability to detect low concentrations of volatile organic compounds produced by biological remains. Cadaver dogs are typically chosen for their stamina, agility, and olfactory sensitivity. However, what is not taken into account often is the size of the animal and the expense of maintaining and training the animal. Cadaver dogs are typically large breeds that cannot fit in …

Markov Chain Analysis Comparison, Thomas Robert Prouty

Undergraduate Honors Capstone Projects

This Honors Capstone was proposed as a method to develop a greater understanding of modern model-checking tools. To do this the student chose to analyze and compare the results of the tools Prism, Storm, and Stamina. To evaluate the effectiveness of each tool, comparisons were made of the results for running each tool on a simplified communication network.

The simplified communication network model used was a CTMC (Continuous-Time Markov Chain) model that employed correct signal transitions and erroneous bit flipping transitions. This was done in an effort to simulate possible errors and faults that can occur between a provider and …

A Study Of A Monolithic Pulsed Fiber Laser With High-Peak And Average Power, Mark Mihalik

All Theses

Fiber lasers with high peak power, pulse energy and average power have numerous industrial applications. This project aimed to build a Master Oscillator Power Amplification fiber laser using commercial components and specialty fiber designed by Clemson University to exceed the power and energy targets of a previous Q-switched fiber laser design. The specialty fiber has a low numerical aperture of 0.028 and a unique geometric core design to minimize amplified spontaneous emission and reduce nonlinear effects in order to produce a high-peak power and high per pulse energy. The two stage, monolithic design targets 3.1 mJ per pulse, average power …

Deep Learning-Based Turkish Spelling Error Detection With A Multi-Class False Positive Reduction Model, Burak Aytan, Cemal Okan Şakar

Turkish Journal of Electrical Engineering and Computer Sciences

Spell checking and correction is an important step in the text normalization process. These tasks are more challenging in agglutinative languages such as Turkish since many words can be derived from the root word by combining many suffixes. In this study, we propose a two-step deep learning-based model for misspelled word detection in the Turkish language. A false positive reduction model is integrated into the system to reduce the false positive predictions originating from the use of foreign words and abbreviations that are commonly used in Internet sharing platforms. For this purpose, we create a multi-class dataset by developing a …

A Novel Deep Learning, Camera, And Sensorbased System For Enforcing Hand Hygiene Compliance In Healthcare Facilities, Samyak Shrimali, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

Hospital-acquired infections are a major cause of death worldwide, and poor hand hygiene compliance is a primary reason for their spread. This paper proposes an artificial intelligence, microcontroller, and sensor-based system that monitors and improves staff hand hygiene compliance at various critical points in a hospital. The system uses a Convolutional Neural Network (CNN) to detect and track if staff have followed the WHO hand rub/hand wash guidelines at alcohol dispensers, hospital sinks, and patient beds. The system also uses RFID tags, vibration motors, LEDs, and a central server to identify staff, alert them of their cleaning requirements, monitor their …

A Pwm Method For Reducing Dv/Dt And Switching Losses In Two-Stage Power Converters, Mahima Gupta, Abhijeet Prem

Electrical and Computer Engineering Faculty Publications and Presentations

Today's semiconductor devices are accompanied by high switching frequencies (> kilo-hertz) and small transition times (< micro-seconds). Such fast transition times are accompanied by undesirable effects such as voltage overshoots at the load terminals, ground leakage currents, wide-band electromagnetic noise, etc. With the advent of wide band-gap devices, several applications are moving towards higher switching frequency operation with at-least an order of magnitude reduction in transition times. While these characteristics are considered necessary to break the next-generation barriers in power density, efficiency and applicability, the undesirable effects due to faster transitions are expected to present obstacles. This work proposes a PWM approach to modify the shape of the switching voltages to overcome the disadvantages of the fast transition times without any increase in switching losses. In fact, several of the switching transitions feature ZVS operation, resulting in reduced switching losses. The paper discusses the analytical details of the approach using a simple DC-DC boost-buck converter and extends it to a DC to three-phase AC converter using the principles of space vector modulation. The paper presents detailed simulation and comparative results in terms of voltage over-shoots over long cables, loss calculations and electromagnetic noise. Results from a laboratory-scale working prototype confirm the benefits of the proposed approach in terms of EMI and loss reduction.

The Networked Nitrous Node: A Low-Power Field-Deployable Cots-Based N2o Gas Sensor Platform, Ronaldo Leon, Wenyu Bi, Eyal Eynis, Travis Johnson, Wei Yan, David C. Burnett, John M. Acken

Electrical and Computer Engineering Faculty Publications and Presentations

We present a wireless nitrous oxide (N 2 O) gas sensor system consisting of a commercial high-current infrared N 2 O sensor wrapped in a “smart” sensor framework to make it suitable for battery-powered deployment. This framework consists of wireless mesh networking, data storage, additional environmental sensors, and a gas sensor power control circuit managed by a central microcontroller. The N 2 O sensor is the first order consumer of power and sampling N 2 O at approximately ten minute intervals yields an estimated system lifetime of 63 days when using four 18650 Li-ion batteries. The node stores data locally …

Deep Reinforcement Learning And Game Theoretic Monte Carlo Decision Process For Safe And Efficient Lane Change Maneuver And Speed Management, Shahab Karimi

All Dissertations

Predicting the states of the surrounding traffic is one of the major problems in automated driving. Maneuvers such as lane change, merge, and exit management could pose challenges in the absence of intervehicular communication and can benefit from driver behavior prediction. Predicting the motion of surrounding vehicles and trajectory planning need to be computationally efficient for real-time implementation. This dissertation presents a decision process model for real-time automated lane change and speed management in highway and urban traffic. In lane change and merge maneuvers, it is important to know how neighboring vehicles will act in the imminent future. Human driver …

Design And Implementation Of High-Efficiency, Lightweight, System-Friendly Solid-State Circuit Breaker, Dehao Qin

All Dissertations

Direct current (DC) distribution system has shown potential over the alternative current (AC) distribution system in some application scenarios, e.g., electrified transportation, renewable energy, data center, etc. Because of the fast response speed, DC solid-state circuit breaker (SSCB) becomes a promising technology for the future power electronics intensive DC energy system with fault-tolerant capability. First, a thorough literature survey is performed to review the DC-SSCB technology. The key components for DC-SSCB, including power semiconductors, topologies, energy absorption units, and fault detection circuits, are studied. It is observed that the prior studies mainly focus on the basic interruption capability of the …

Enhanced Mobile Networking Using Multi-Connectivity And Packet Duplication In Next-Generation Cellular Networks, Prabodh Mishra

All Dissertations

Modern cellular communication systems need to handle an enormous number of users and large amounts of data, including both users as well as system-oriented data. 5G is the fifth-generation mobile network and a new global wireless standard that follows 4G/LTE networks. The uptake of 5G is expected to be faster than any previous cellular generation, with high expectations of its future impact on the global economy. The next-generation 5G networks are designed to be flexible enough to adapt to modern use cases and be highly modular such that operators would have the flexibility to provide selective features based on user …

A Study On Asymmetric Perfect Vortex: Fractional Orbital Angular Momentum And Nonlinear Interaction, Kunjian Dai

All Dissertations

In this work, the manipulation including generation and detection of the asymmetric perfect vortex (APV) carrying fractional orbital angular momentum (OAM) was demonstrated and discussed. All the manipulation of the modes is in real-time which provides a perfect tool for sensing the dynamic properties of complex media. The OAM-involved nonlinear conversion, specifically the second-harmonic generation (SHG) using the APV and asymmetric Bessel-Gaussian (BG) beams was studied in detail.

The generation and detection of the APV are based on the HOBBIT concept which includes acoustic optical deflector (AOD) and log-polar coordinate transformation optics. The RF signal driving the AOD allows the …

When Less Is More: How Increasing The Complexity Of Machine Learning Strategies For Geothermal Energy Assessments May Not Lead Toward Better Estimates, Stanley P. Mordensky, John Lipor, Jacob Deangelo, Erick R. Burns, Cary R. Lindsey

Electrical and Computer Engineering Faculty Publications and Presentations

Previous moderate- and high-temperature geothermal resource assessments of the western United States utilized data-driven methods and expert decisions to estimate resource favorability. Although expert decisions can add confidence to the modeling process by ensuring reasonable models are employed, expert decisions also introduce human and, thereby, model bias. This bias can present a source of error that reduces the predictive performance of the models and confidence in the resulting resource estimates.

Our study aims to develop robust data-driven methods with the goals of reducing bias and improving predictive ability. We present and compare nine favorability maps for geothermal resources in the …

Trajectory Analysis For Driving Safety Quantification, Michael I. Chang

UNLV Theses, Dissertations, Professional Papers, and Capstones

In order to evaluate the efficacy of the skid recovery exercise in the Driver’s Edge teenage driving program, a process is established to determine the trajectories of vehicles from recorded videos, compare them in terms of similarity through dynamic time warping (DTW), and then analyze the similarity measurements to assess whether the program has a significant effect on driving ability by repeated measures analysis of variance (rANOVA). The video is analyzed by Harris corner detection and Lucas-Kanade optical flow method to ascertain the vehicle trajectories. A homography is then estimated to translate coordinates from video into real-world. The instructor and …

Classification Of Electrical Current Used In Electroplastic Forming, Tyler Grimm

All Dissertations

Electrically assisted manufacturing (EAM) is the direct application of an electric current to a workpiece during manufacturing. This advanced manufacturing process has been shown to produce anomalous effects which extend beyond the current state of modeling of thermal influences. These purported non-thermal effects have collectively been termed electroplastic effects (EPEs).

While there is a distinct difference in results between steady-state (ideal DC) testing and pulsed current testing, the very definition of these two EAM methods has not been well established. A "long" pulse may be considered DC current; a "short" pulse may produce electroplastic effects; and even "steady-state" current shapes …

Stream Processor Development Using Multi-Threshold Null Convention Logic Asynchronous Design Methodology, Wassim Khalil

Graduate Theses and Dissertations

Decreasing transistor feature size has led to an increase in the number of transistors in integrated circuits (IC), allowing for the implementation of more complex logic. However, such logic also requires more complex clock tree synthesis (CTS) to avoid timing violations as the clock must reach many more gates over larger areas. Thus, timing analysis requires significantly more computing power and designer involvement than in the past. For these reasons, IC designers have been pushed to nix conventional synchronous (SYNC) architecture and explore novel methodologies such as asynchronous, self-timed architecture. This dissertation evaluates the nominal active energy, voltage-scaled active energy, …

The Growth And Characterization Of Inn Quantum Dots Using Droplets Epitaxy In Mbe, Malak Refaei

Graduate Theses and Dissertations

III-nitride semiconductor material systems offer great potential for next-generation optoelectronic devices due to their direct bandgaps, which vary from 0.7 eV (InN) to 3.5 eV (GaN) to 6.2 eV (AlN), as well as their other unique properties. InN has gained much less attention than GaN and AlN within this family of semiconductors due to its complicated low-temperature growth. However, the prediction that an InN quantum well on GaN can become a two-dimensional (2D) topological insulator has resulted in expanding the research interest in InN. At the same time, this renewed interest has begun to reveal that the formation of an …

Addressing The Challenged Of Dcop Based Decision-Making Algorithms In Modern Power Systems, Luis Daniel Ramirez Burgueno

Open Access Theses & Dissertations

Natural disasters have been determined as the leading cause of power outages, causing not only huge economic losses, but also the interruption of crucial welfare activities and the arise of security concerns. Because of the later, decision-making considering grid modernization, power system economics, and system resiliency has been a crucial theme in power systemsâ?? research. The need to better withstand catastrophic events and reducing the dependency of bulky generating units has propelled the development and better management of behind-the-meter generation or distributed energy resources (DERs). DERs can assist in the grid in different manners, not only by meeting energy demand …

Development Of A Cost-Constrained Intelligent Prosthetic Knee With Real-Time Machine Learning, Predictive Stumble Control, Lucas Jonathan Galey

Open Access Theses & Dissertations

The field of biomechatronics is evolving quickly with advances in computer science, biology, and electrical and mechanical engineering. Coupled with increased interests in machine learning (ML) across all industry sectors, there are opportunities to leverage advanced analytics in uniquely complex problems. This study aimed to deploy real-time ML predictions in a novel microprocessor-controlled prosthetic knee (MPK) device capable of identifying and responding to stumble-events to reduce amputee fall prevalence. Innately, stumbling is a chaotic event. Current MPKs operate by detecting gait characteristics and reacting to preprogrammed states. While these systems are beneficial in significant ways, such as energy expenditure and …

Cyber-Physical Production Systems And Their Practical Integration And Application With Simio Software, Jose Carlos Garcia Marquez Basaldua

Open Access Theses & Dissertations

Industry 4.0 comprises a diverse array of technologies and components that are revolutionizing the manufacturing industry, from Digital Twins, Cyber-Physical Systems and Augmented Reality. The elements that englobe Industry 4.0 vary from framework to framework. Nevertheless, there are similarities in the available literature on what constitutes Industry 4.0. Some of the most critical components specified by the available literature include Digital Twins and Cyber-Physical Systems. A Factory Digital Twin is a virtual representation of a production system that can mimic the behavior of the physical asset. Moreover, a digital twin must have synchronization with its physical twin (i.e., production floor), …

The Active Cryocubesat Technology: Active Thermal Control For Small Satellites, Lucas S. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Modern CubeSats and Small Satellites have advanced in capability to tackle science and technology missions that would usually be reserved for more traditional, large satellites. However, this rapid growth in capability is only possible through the fast-to-production, low-cost, and advanced technology approach used by modern small satellite engineers. Advanced technologies in power generation, energy storage, and high-power density electronics have naturally led to a thermal bottleneck, where CubeSats and Small Satellites can generate more power than they can easily reject. The Active CryoCubeSat (ACCS) is an advanced active thermal control technology (ATC) for Small Satellites and CubeSats, which hopes to …