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Articles 31 - 60 of 1276
Full-Text Articles in Engineering
The Modernization Of Large Power Transformer Tanks, Babajide O. Williams
The Modernization Of Large Power Transformer Tanks, Babajide O. Williams
Electronic Theses and Dissertations
Due to the current demands placed on the power grid in terms of climate change, increasing urbanization, and terrorist attacks, the U.S. government in response to these demands, mandated that all the grid components be modernized in order to increase their reliability. As a critical component of the grid, Large Power Transformers (LPTs) play a key role in ensuring sustainable power generation and distribution. A literature search performed in this work and the analysis of data retrieved from the search showed that the tanks of these LPTs are critical to their durability, longevity, and reliability. Therefore, the reliability of LPTs …
Computational Analysis Investigation Of A Piezoelectrically Actuated Micropump For Air Sniffing Applications, Yameema Babu Lopez
Computational Analysis Investigation Of A Piezoelectrically Actuated Micropump For Air Sniffing Applications, Yameema Babu Lopez
Electronic Theses and Dissertations
Micro-Electro-Mechanical Systems (MEMS) refers to a technology which uses microfabrication technology to fabricate miniaturized devices and systems. MEMS based technologies have paved the way for miniaturization and manufacturing of devices with applications ranging from biological to fluid engineering. This interdisciplinary nature of MEMS has given rise to an emerging field called microfluidics which studies devices that pump, control and sense small volumes of fluids. This work aims to investigate a piezoelectric micropump that can mimic mammalian olfaction for e-nose applications. A comprehensive literature review was conducted on all the available micropumps. A piezoelectric micropump was chosen as the candidate for …
Control And Protection Solutions For Resilient Protective Relaying Of Modern Power Systems, Abdallah Alaa Mohieldien Aboelnaga
Control And Protection Solutions For Resilient Protective Relaying Of Modern Power Systems, Abdallah Alaa Mohieldien Aboelnaga
Electronic Theses and Dissertations
Renewable energy sources (RESs) are permeating the power grid due to their importance in reducing air pollution and fuel consumption. These sources require synchronization with the power grid using inverters that must meet grid code (GC) requirements. During fault conditions, GCs enforce inverter interfaced RESs (IIRESs) to follow reactive current generation (RCG) requirements to enhance grid stability. However, it could adversely affect protection functions, e.g., phase selection methods (PSMs), operations. The main objective of this dissertation is to enhance the power system resiliency by determining the faulty phase(s) accurately. This is achieved by investigating the root causes behind the failure …
Novel Approach For Non-Invasive Prediction Of Body Shape And Habitus, Emma Young
Novel Approach For Non-Invasive Prediction Of Body Shape And Habitus, Emma Young
Electronic Theses and Dissertations
While marker-based motion capture remains the gold standard in measuring human movement, accuracy is influenced by soft-tissue artifacts, particularly for subjects with high body mass index (BMI) where markers are not placed close to the underlying bone. Obesity influences joint loads and motion patterns, and BMI may not be sufficient to capture the distribution of a subject’s weight or to differentiate differences between subjects. Subjects in need of a joint replacement are more likely to have mobility issues or pain, which prevents exercise. Obesity also increases the likelihood of needing a total joint replacement. Accurate movement data for subjects with …
The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo
The Future Is Now In Twisted Coil Polymer Actuators (Tcpa), Ryan Ronquillo
Electronic Theses and Dissertations
This thesis aimed to fabricate and test twisted coiled polymer actuators (TCPA) to understand the mechanical and thermal aspects of this artificial muscle fiber. The purpose of this thesis was to find a linear relationship using the LVDT sensor, fabricating TCPA fibers, and interpreting the data. The project tested whether nylon/polymer could be used as a better artificial muscle fiber.
This research accomplished three goals: (1) designing and fabricating a system capable of creating supercoiled muscle fibers consistently, (2) calibrating the Linear Variable Differential Transformer (LVDT) and Core, and (3) analyzing/interpreting the data of the Twisted Coiled Polymer Actuators (TCPA) …
The Study Of Corrosion On Additive-Manufactured Metals., Braydan Daniels
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 …
Modeling, Simulation And Control Of Microrobots For The Microfactory., Zhong Yang
Modeling, Simulation And Control Of Microrobots For The Microfactory., Zhong Yang
Electronic Theses and Dissertations
Future assembly technologies will involve higher levels of automation in order to satisfy increased microscale or nanoscale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to the microelectronics and MEMS industries, but less so in nanotechnology. With the boom of nanotechnology since the 1990s, newly designed products with new materials, coatings, and nanoparticles are gradually entering everyone’s lives, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than top-down robotic assembly. This is due to considerations of volume handling of large …
Unsupervised Bidirectional Mr To Ct Synthesis Based On Generative Adversarial Networks, Jiayuan Wang
Unsupervised Bidirectional Mr To Ct Synthesis Based On Generative Adversarial Networks, Jiayuan Wang
Electronic Theses and Dissertations
Magnetic resonance (MR) and computer tomography (CT) images are two typical types of medical images that provide mutually-complementary information for accurate clinical diagnosis and treatment. However, obtaining both images may be limited due to some considerations such as cost, radiation dose, and modality missing. Recently, medical image synthesis has aroused gaining research interest to cope with this limitation. In this thesis, we proposed unsupervised bidirectional learning models based on generative adversarial networks (GANs) to synthesize medical images from unpaired data. The first model is dual contrast CycleGAN (DC-cycleGAN), where a dual contrast (DC) loss is introduced into the CycleGAN's discriminators …
Unsupervised Learning Algorithm For Noise Suppression And Speech Enhancement Applications, Abdullah Zaini Alsheibi
Unsupervised Learning Algorithm For Noise Suppression And Speech Enhancement Applications, Abdullah Zaini Alsheibi
Electronic Theses and Dissertations
Smart and intelligent devices are being integrated more and more into day-to-day life to perform a multitude of tasks. These tasks include, but are not limited to, job automation, smart utility management, etc., with the aim to improve quality of life and to make normal day-to-day chores as effortless as possible. These smart devices may or may not be connected to the internet to accomplish tasks. Additionally, human-machine interaction with such devices may be touch-screen based or based on voice commands. To understand and act upon received voice commands, these devices require to enhance and distinguish the (clean) speech signal …
Deep Learning For Power Flow Estimation And High Impedance Fault Detection, Kun Yang
Deep Learning For Power Flow Estimation And High Impedance Fault Detection, Kun Yang
Electronic Theses and Dissertations
My thesis is divided into two parts.
The first part is: “Optimal Power Flow Estimation Using One-Dimensional Convolutional Neural Network [1]“. Optimal power flow (OPF) is an important research topic in power system operation and control decisions. Traditional OPF problems are solved through dynamic optimization with nonlinear programming techniques. For a large power system with large amounts of variables and constraints, the solving process would take a long time. This paper presents a new method to quickly estimate the OPF results using a one-dimensional convolutional neural network (1D-CNN). The OPF problem is treated as a high-dimensional mapping between the load …
Power System Dynamic Control And Performance Improvement Based On Reinforcement Learning, Wei Gao
Power System Dynamic Control And Performance Improvement Based On Reinforcement Learning, Wei Gao
Electronic Theses and Dissertations
This dissertation investigates the feasibility and effectiveness of using Reinforcement Learning (RL) techniques for power system dynamic control, particularly voltage and frequency control. The conventional control strategies used in power systems are complex and time-consuming due to the complicated high-order nonlinearities of the system. RL, which is a type of neural network-based technique, has shown promise in solving these complex problems by fitting any nonlinear system with the proper network structure.
The proposed RL algorithm, called Guided Surrogate Gradient-based Evolution Strategy (GSES) determines the weights of the policy (which generates the action for our control reference signal) without back-propagation process …
Validation Of Expanded Trend-To-Trend Cross-Calibration Technique And Its Application To Global Scale, Ramita Shah
Validation Of Expanded Trend-To-Trend Cross-Calibration Technique And Its Application To Global Scale, Ramita Shah
Electronic Theses and Dissertations
The expanded Trend-to-Trend (T2T) cross-calibration technique has the potential to calibrate two sensors in much less time and provides trends on daily assessment basis. The trend obtained from the expanded technique aids in evaluating the differences between satellite sensors. Therefore, this technique was validated with several trusted cross-calibration techniques to evaluate its accuracy. Initially, the expanded T2T technique was validated with three independent RadcaTS RRV, DIMITRI-PICS, and APICS models, and results show a 1% average difference with other models over all bands. Further, this technique was validated with other SDSU techniques to calibrate the newly launched satellite Landsat 9 with …
Artificial Emotional Intelligence In Socially Assistive Robots, Hojjat Abdollahi
Artificial Emotional Intelligence In Socially Assistive Robots, Hojjat Abdollahi
Electronic Theses and Dissertations
Artificial Emotional Intelligence (AEI) bridges the gap between humans and machines by demonstrating empathy and affection towards each other. This is achieved by evaluating the emotional state of human users, adapting the machine’s behavior to them, and hence giving an appropriate response to those emotions. AEI is part of a larger field of studies called Affective Computing. Affective computing is the integration of artificial intelligence, psychology, robotics, biometrics, and many more fields of study. The main component in AEI and affective computing is emotion, and how we can utilize emotion to create a more natural and productive relationship between humans …
Method Of Validating Satellite Surface Reflectance Product Using Empirical Line Method, Meghraj Kc
Method Of Validating Satellite Surface Reflectance Product Using Empirical Line Method, Meghraj Kc
Electronic Theses and Dissertations
Atmospherically corrected surface reflectance (SR) products are used for reliable monitoring of land surfaces and are the standard products of Landsat sensors. Due to increased demand for SR products, a need exists to verify that the L2C2 (Level-2 Collection-2) SR products are precise and accurate. The Level-2 Collection 2 (L2C2) SR Product is processed satellite imagery data that corrects for atmospheric effects such as absorption and scattering, providing a more accurate representation of Earth's surface. The validation of SR products using ground truth measurement is essential. This study aims to develop and evaluate a validation methodology for satellite SR products. …
Probing Signal-Based Data-Driven Modeling Of Power Electronics Smart Converter Dynamics Using Power Hardware-In-The-Loop, Nischal Guruwacharya
Probing Signal-Based Data-Driven Modeling Of Power Electronics Smart Converter Dynamics Using Power Hardware-In-The-Loop, Nischal Guruwacharya
Electronic Theses and Dissertations
The main objective of this dissertation is to develop a generalized simulation and modeling framework for extracting dynamics of power electronic converters (PECs) with grid support functions (GSFs) and validate model accuracy through experimental comparison with physical measurements. The dynamic models obtained from this modeling framework aim to facilitate accurate dynamic analysis of a highly integrated power system comprising inverter-based resources (IBRs), specifically for stability assessment. These dynamic models helped in reducing simulation time and computational complexity, thereby enhancing efficiency. Moreover, it provides valuable insights for utilities and grid operators involved in effective system planning, operation, and dispatch. The dynamics …
Evaluating The Impact Of Increased Cycling On Thermal Power Plants Due To Wind Energy Penetration In The Midwest: A Case Study, Joscelyne Larson
Evaluating The Impact Of Increased Cycling On Thermal Power Plants Due To Wind Energy Penetration In The Midwest: A Case Study, Joscelyne Larson
Electronic Theses and Dissertations
One of the most significant shifts in the mix of U.S. electricity generation over the past few years has been the rapid expansion of renewable energy resources, especially solar and wind. However, fossil fuels are still necessary to fulfill the world’s energy requirements. Despite efforts to increase the use of renewable energy sources, these sources can be at times unreliable, causing countries around the world to continue to rely on base load units such as coal and natural gas. This decrease in fossil fuels and increase in renewable energy sources presents many complex issues in terms of power system planning, …
Evaluation Of Low-Cost Radiometer For Surface Reflectance Re-Trieval And Orbital Sensor’S Validation, Dinithi Siriwardana Pathiranage
Evaluation Of Low-Cost Radiometer For Surface Reflectance Re-Trieval And Orbital Sensor’S Validation, Dinithi Siriwardana Pathiranage
Electronic Theses and Dissertations
This paper evaluates the Arable Mark 2 sensor, an automated and low-cost radiometer, for its potential to retrieve surface reflectance data and validate orbital sensors such as the Landsat-8 (L8) Operational Land Imager (OLI) Level 2 product. While orbital sensors are widely used for monitoring solar radiation changes, managing natural resources, and understanding climatic trends, atmospheric effects can make it challenging to obtain accurate measurements. Equipped with multiple sensors, including long-wave and short-wave radiometers, the Arable Mark 2 sensor can measure upwelling and downwelling irradiance to calculate surface reflectance. To assess the accuracy and consistency of the Arable Mark 2 …
Extended Cross-Referenced Analysis Using Data From The Landsat 8 And 9 Underfly Event, Garrison Gross
Extended Cross-Referenced Analysis Using Data From The Landsat 8 And 9 Underfly Event, Garrison Gross
Electronic Theses and Dissertations
The Landsat 8 and 9 Underfly Event occurred in November 2021, where Landsat 9 flew beneath Landsat 8 in the final stages before settling in its final orbiting path. An analysis was performed on the images taken during this event, which resulted in a cross-referenced with uncertainties estimated to be less than 0.5%. This level of precision was due in part to the near-identical sensors aboard each instrument as well as the underfly event itself, which allowed the sensors to take nearly the exact same image at nearly the exact same time. This initial calibration was applied before the end …
The Development Of Dark Hyperspectral Absolute Calibration Model Using Extended Pseudo Invariant Calibration Sites At A Global Scale: Dark Epics-Global, Padam Bahadur Karki
The Development Of Dark Hyperspectral Absolute Calibration Model Using Extended Pseudo Invariant Calibration Sites At A Global Scale: Dark Epics-Global, Padam Bahadur Karki
Electronic Theses and Dissertations
This research aimed to develop a novel dark hyperspectral absolute calibration (DAHAC) model using stable dark targets of "Global Cluster - 36" (GC-36), one of the clusters from "300 Class Global Classification." The stable dark sites were identified from GC-36 called "Dark EPICS-Global" covering the surface types viz; dark rock, volcanic area, and dark sand. The Dark EPICS-Global shows a temporal variation of 0.02 unit reflectance. This work uses the Landsat-8 (L8) Operational Land Imager (OLI) , Sentinel-2A (S2A) Multispectral Instrument (MSI) , and Earth Observing One (EO-1) Hyperion data for the DAHAC model development, where well-calibrated L8 and S2A …
Electrode And Electrolyte Design To Develop Advanced Battery Technologies For Large Scale Energy Storage, Wei He
Electronic Theses and Dissertations
Large-scale energy storage devices play a key role in regulating the renewable energy to build a carbon-free sustainable future, but the widely used lithium-ion batteries cannot meet the demands because of the limited lithium resource and high cost. Thus, it is urgent to develop next-generation battery technologies with low cost and high safety. Sodium-ion battery is considered as a promising candidate due to the abundant sodium resources and low cost. Its practical application, however, is hindered by the absence of the advanced electrode materials. The tin-based anodes deliver high theoretical capacities and show great promise for the sodium-ion batteries, but …
Nio Nanoparticles-Decorated Carbon Fiber Cloth As Lithiophilic Host Material For Stable Lithium Metal Batteries, Sarwar Ahmed
Nio Nanoparticles-Decorated Carbon Fiber Cloth As Lithiophilic Host Material For Stable Lithium Metal Batteries, Sarwar Ahmed
Electronic Theses and Dissertations
Lithium metal is considered the Holy Grail for the anode for next-generation rechargeable batteries. Lithium metal has the highest theoretical capacity and lowest anode potential with respect to the standard hydrogen electrode (SHE). However, its commercialization is hindered by uncontrolled dendrite growth, weak solid electrolyte interphase (SEI), and low coulombic efficiency. The dendrite formation leads to a short circuit between the anode and cathode, which creates a dangerous safety issue. Several host materials and artificial SEI layers have been developed to suppress these issues. However, the effectiveness of these solutions is limited. More research is needed to develop more efficient …
Methods On Implementing Radar And Antenna Solutions To Defense And Biomedical Problems, Jalexis E. Vanga Guzman
Methods On Implementing Radar And Antenna Solutions To Defense And Biomedical Problems, Jalexis E. Vanga Guzman
Electronic Theses and Dissertations
Growing developments in antenna and radio frequency systems have created a strong incentive for researchers to study and apply electromagnetic (EM)-based solutions to modern defense and biomedical problems. The ability to transmit and receive EM waves using antenna systems has not only increased global connectivity, but also increased the need for innovation in antenna size reduction and development of radar systems.
Size reduction techniques have been extensively studied for antennas after the development of electrically small antennas (ESAs) which follow Chu’s limit. ESAs allow the implementation of antennas with much smaller foot-size than traditional full-sized designed while keeping the same …
Design And Fabrication Of A Force-Displacement Control Mechanism For Bone-Surgical Tool Testing, Kenneth Nwagu
Design And Fabrication Of A Force-Displacement Control Mechanism For Bone-Surgical Tool Testing, Kenneth Nwagu
Electronic Theses and Dissertations
This project focuses on the design and fabrication of an experimental setup for orthopedic-tool testing, tailored for a surgical instrumentation company. The multifaceted project encompasses a literature review, conceptual design, prototyping, and rigorous testing, resulting in a versatile control system capable of assessing various orthopedic tools, including bone drills, saws, burrs, and power handpieces.
Orthopedic surgical procedures (which include cutting and/or drilling into bone) often need to be performed on bones for faster recovery. The drilling and cutting process can cause an increase in temperature at the cutting site which can cause bone necrosis. The tools also need to be …
Analysis Of Dual-Element Antenna Configurations, Grant J. Evans
Analysis Of Dual-Element Antenna Configurations, Grant J. Evans
Electronic Theses and Dissertations
Dual-dipole antennas have been extensively researched previously for their bandwidth enhancing effect on Yagi type antennas. In this thesis, dual-dipole antennas are fabricated and measured. These experimental measurement results are verified with simulated values. First, a standard dual-dipole antenna is investigated and found that the high magnitude, opposite current directions on the dipole arms are the reasoning behind the creation of a high gain mode. This pattern is similar to a Yagi antenna. Next, a dual-band implementation of the dual-dipole antenna is shown, with two distinct resonances in a lower band and an upper band. Both bandwidths exhibit a dipole …
Enhancing Traffic Safety In Unpredicted Environments With Integration Of Adas Features With Sensor Fusion In Intelligent Electric Vehicle Platform With Implementation Of Environmental Mapping Technology, David S. Obando Ortegon
Enhancing Traffic Safety In Unpredicted Environments With Integration Of Adas Features With Sensor Fusion In Intelligent Electric Vehicle Platform With Implementation Of Environmental Mapping Technology, David S. Obando Ortegon
Electronic Theses and Dissertations
A major objective on society is to reduce the number of accidents and fatalities on the road for drivers, and pedestrians. Therefore, the automotive engineering field is working on this problem through the development and integration of safety technologies such as advanced driving assistance systems. For this reason, this work was intended to develop and evaluate the performance of different ADAS features and IV technologies under unexpected scenarios. This by the development of safety algorithms applied to the intelligent electric vehicle designed and built in this work, through the use of ADAS sensors based on sensor fusion. Evaluation of AEB, …
Predicting Jamming Systems Frequency Hopping Sequences Using Artificial Neural Networks, Charles Strickland
Predicting Jamming Systems Frequency Hopping Sequences Using Artificial Neural Networks, Charles Strickland
Electronic Theses and Dissertations
This work proposes a neural network architecture that was designed to predict and reverse engineer frequency hopping jamming systems. The neural network was initially optimized for use with a 12th order linear shift feedback register maximum length sequence utilizing a minimal polynomial as the characteristic polynomial. This neural network was then scaled to accommodate 7 different sequences, of orders 6 through 12. The neural network was trained for these sequences using training data that is 10 times the length of the sequence. This information is then used to generate a hopping sequence that reduces the jamming interference to 0 with …
Single Hydrophone Underwater Localization Approach In Sallow Waters, Faraz Talebpour
Single Hydrophone Underwater Localization Approach In Sallow Waters, Faraz Talebpour
Electronic Theses and Dissertations
Applications of underwater signal processing are essential for environmental monitoring. Remote monitoring and passive sound source localization in an underwater environment can provide great insight into geological studies, environmental changes and marine lives monitoring. While various methods are available for Localization, they mostly employ arrays of hydrophones, requiring synchronization or prior knowledge of the source signals, which can prove costly, complicated, and hard to maintain. Remote monitoring applications require very high-range passive localization methods; and, given the frequency-selective nature of ambient noise and other channel parameters, current localization methods have short-distance range estimation or high localization error for long distances. …
2d Hybrid Analytical Model Based Performance Optimization For Linear Induction Motors, Michael Thamm
2d Hybrid Analytical Model Based Performance Optimization For Linear Induction Motors, Michael Thamm
Electronic Theses and Dissertations
In this thesis the domain of double-layer, single-sided, 3-phase, integral slot winding, linear induction motor (LIM)s is analyzed. Motor meta parameters such as slots and poles are difficult to optimize since they drastically effect the configuration of the motor and require heuristic optimization implementations.
A non-dominated sorting genetic algorithm II (NSGAII) was implemented with the Platypus-Opt Python library. It serves as a robust, yet flexible integration while maximizing thrust and minimizing the mass of each motor iteration. Each iteration was accurately modelled using the hybrid analytical model (HAM), producing the necessary performance parameters for the NSGAII’s objective function. Field plotting …
Rapid Prototyping And Functional Verification Of Power Efficient Ai Processor On Fpga, Vivek Liladhar Ladhe
Rapid Prototyping And Functional Verification Of Power Efficient Ai Processor On Fpga, Vivek Liladhar Ladhe
Electronic Theses and Dissertations
Prototyping a design on a Field Programmable Gate Array (FPGA) involves different stages such as developing a design, performing synthesis, handling placement and routing and finally generating the programming bit file for the FPGA. After successful completion of the above stages, it is important to functionally verify the design. This thesis addresses the challenges involved in rapid prototyping and functional verification of a low power AI processor provided by the industry partner. This research also addresses the methodology used in generating programming bit file and testing the design. Traditional method of testing a design using RTL level testbench utilises more …
Engineering The Spectrum Of Near-Field Thermal Radiation, Saman Zare
Engineering The Spectrum Of Near-Field Thermal Radiation, Saman Zare
Electronic Theses and Dissertations
Thermal emission observed at sub-wavelength distances from the thermal source is referred to as near-field thermal radiation. Thermal radiation in the near-field regime can exceed Planck’s blackbody limit by orders of magnitude and be quasi-monochromatic. Due to these unique properties, near-field thermal radiation is very promising for several thermal management and energy harvesting applications. Many of these applications, such as nanogap thermophotovoltaics and thermal rectification, require near-field spectra that are not found among natural materials. Artificial metamaterials, which are engineered at the sub-wavelength scale, have been theoretically proposed for tuning the spectrum of near-field thermal radiation. However, engineering the near-field …