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Articles 61 - 90 of 617

Full-Text Articles in Electrical and Computer Engineering

High-Power Power Conditioning Systems For Medium-Voltage Applications, Ahmed Rahouma Fares Rahouma Aug 2024

High-Power Power Conditioning Systems For Medium-Voltage Applications, Ahmed Rahouma Fares Rahouma

Graduate Theses and Dissertations

The purpose of this dissertation is to address the background, theoretical analyses, design methodologies, and evaluation techniques relevant to high-power power conditioning systems (PCSs) tailored for medium-voltage (MV) applications. Conventional PCSs, reliant on line-frequency transformers (LFTs), suffer from many problems including low power densities, inflexible designs, and scalability constraints. Employing multilevel converters (MLCs), particularly cascaded H-bridge topology, eliminates the need for these LFTs. A key focus lies in minimizing the number of cascaded building blocks by harnessing MV power switching modules. The dissertation makes two primary contributions: firstly, it offers a design methodology for MV-PCS, facilitating the selection of the …

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Modification Of Time-Domain Terahertz Spectroscopy System To Polarimetry Imaging System With Application To Human Breast Cancer Surgical Specimen, Nikita Gurjar Aug 2024

Modification Of Time-Domain Terahertz Spectroscopy System To Polarimetry Imaging System With Application To Human Breast Cancer Surgical Specimen, Nikita Gurjar

Graduate Theses and Dissertations

Breast-conserving therapy (lumpectomy) is one of the most performed breast cancer surgeries in the United States. The best outcome of lumpectomy surgery is achieved when the surgical margins are free of cancer. When remnants of cancer are detected at the surgical margins after the initial operation, a second operation will be required to remove the cancer. Unfortunately, a significant number of patients undergo breast conserving surgery (BCS) at local hospitals that do not have access to immediate on-site pathology leading to high rates of re-excision or reoperation (greater than 30%). Therefore, there is a significant need for new intraoperative technology …

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Impacts Of High-Frequency Operation On Magnetics And Performance On Isolated Power Electronic Converter Design, David Arturo Porras Fernandez Aug 2024

Impacts Of High-Frequency Operation On Magnetics And Performance On Isolated Power Electronic Converter Design, David Arturo Porras Fernandez

Graduate Theses and Dissertations

The pursuit of high-power density and high switching frequency is a central theme in the advancement of power electronic converters. While these parameters offer significant benefits in terms of compactness and performance, they also introduce challenges related to efficiency and thermal management. This doctoral dissertation aims to provides a design framework to analyze the implications of high-frequency operation (> 100 kHz) on magnetics design and performance in power electronic converters, particularly when integrating silicon carbide (SiC) power modules. It examines the advantages and disadvantages of high-frequency operation and delves into its effects on the performance of the converter, focusing on …

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Evaluation, Modeling And Application Of Gallium Nitride Field Effect Transistor, Geno Guillaume Aug 2024

Evaluation, Modeling And Application Of Gallium Nitride Field Effect Transistor, Geno Guillaume

Graduate Theses and Dissertations

Gallium Nitride (GaN) has emerged as one of the leading materials for power devices due to its wide band gap and high electron mobility. The band gap is the minimum energy required to excite an electron up to a state in the conduction band where it can participate in conduction. Because of this, wide band gap (WBG) materials are favorable for various electrical applications. The market for GaN high-electron-mobility transistor (HEMT) is projected to exceed $1.25 billion by 2027. With the increase of market interest, modern technologies emerge that aim to push the boundaries of efficiency for GaN power devices. …

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Modeling, Optimization, And Characterization For Choke Horn Antennas, Ibrahim Nasser I Alquaydheb Aug 2024

Modeling, Optimization, And Characterization For Choke Horn Antennas, Ibrahim Nasser I Alquaydheb

Graduate Theses and Dissertations

This dissertation presents a comprehensive study focusing on the modeling, optimization, and characterization of choke horn antennas (CHAs). An analytical model designed to capture the parameters of CHA and derive the total radiated fields from the choke and waveguide elements is primarily focused on in this work. Compared to the use of simulation software, such as ANSYS HFSS (High Frequency Structure Simulator) or CST Studio, which employs numerical methods to simulate and calculate antenna performance, numerous advantages are offered by the analytical model. Analytical models provide deeper insight into electromagnetic interactions and the principles governing antenna behavior, leading to a …

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React: Recognize Every Action Everywhere All At Once, Naga Venkata Sai Raviteja Chappa, Pha Nguyen, Page Daniel Dobbs, Khoa Luu Jul 2024

React: Recognize Every Action Everywhere All At Once, Naga Venkata Sai Raviteja Chappa, Pha Nguyen, Page Daniel Dobbs, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

In the realm of computer vision, Group Activity Recognition (GAR) plays a vital role, finding applications in sports video analysis, surveillance, and social scene understanding. This paper introduces Recognize Every Action Everywhere All At Once (REACT), a novel architecture designed to model complex contextual relationships within videos. REACT leverages advanced transformer-based models for encoding intricate contextual relationships, enhancing understanding of group dynamics. Integrated Vision-Language Encoding facilitates efficient capture of spatiotemporal interactions and multi-modal information, enabling comprehensive scene understanding. The model’s precise action localization refines joint understanding of text and video data, enabling precise bounding box retrieval and …

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Hatt-Flow: Hierarchical Attention-Flow Mechanism For Group-Activity Scene Graph Generation In Videos, Naga Venkata Sai Raviteja Chappa, Pha Nguyen, Thi Hoang Ngan Le, Page Daniel Dobbs, Khoa Luu Jun 2024

Hatt-Flow: Hierarchical Attention-Flow Mechanism For Group-Activity Scene Graph Generation In Videos, Naga Venkata Sai Raviteja Chappa, Pha Nguyen, Thi Hoang Ngan Le, Page Daniel Dobbs, Khoa Luu

Electrical Engineering and Computer Science Faculty Publications and Presentations

Group-activity scene graph (GASG) generation is a challenging task in computer vision, aiming to anticipate and describe relationships between subjects and objects in video sequences. Traditional video scene graph generation (VidSGG) methods focus on retrospective analysis, limiting their predictive capabilities. To enrich the scene-understanding capabilities, we introduced a GASG dataset extending the JRDB dataset with nuanced annotations involving appearance, interaction, position, relationship, and situation attributes. This work also introduces an innovative approach, a Hierarchical Attention–Flow (HAtt-Flow) mechanism, rooted in flow network theory to enhance GASG performance. Flow–attention incorporates flow conservation principles, fostering competition …

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Low Noise Amplifier For 5ghz Wi-Fi Applications On 22nm, Harshdeep Singh May 2024

Low Noise Amplifier For 5ghz Wi-Fi Applications On 22nm, Harshdeep Singh

Electrical Engineering Undergraduate Honors Theses

More devices than ever are being used to connect to the internet via Wi-Fi than ever before. This creates the demand for improving Wi-Fi standards and wireless transceivers. On of the most important stages of a Wi-Fi receiver is the low noise amplifier (LNA), this is because it is the very first stage after the antenna receives the signal. The LNA is responsible for boasting the incoming signal while adding a low amount of noise to boast the signal enough to make it receptible to the rest of the receiver system. This study sought to design an inductively degenerated common …

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Challenges For Room Temperature Operation Of Electrically Pumped Gesn Lasers, A. R. Ellis, D. A. Duffy, I. P. Marko, S. Acharya, W. Du, S. Q-. Yu, S. J. Sweeney May 2024

Challenges For Room Temperature Operation Of Electrically Pumped Gesn Lasers, A. R. Ellis, D. A. Duffy, I. P. Marko, S. Acharya, W. Du, S. Q-. Yu, S. J. Sweeney

Electrical Engineering and Computer Science Faculty Publications and Presentations

Recent demonstrations of room-temperature lasing in optically pumped GeSn show promise for future CMOS compatible lasers for Si-photonics applications. However, challenges remain for electrically pumped devices. Investigation of the processes that limit device performance is therefore vital in aiding the production of future commercial devices. In this work, a combined experimental and modelling approach is utilised to explore the dominant loss processes in current devices. By manipulating the band structure of functioning devices using high hydrostatic pressure techniques at low temperature, the dominant carrier recombination pathways are identified. This reveals that 93 ± 5% of the threshold current is attributable …

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A 10 Kv Sic Mosfet Power Module With Optimized System Interface And Electric Field Distribution, Xiaoling Li May 2024

A 10 Kv Sic Mosfet Power Module With Optimized System Interface And Electric Field Distribution, Xiaoling Li

Graduate Theses and Dissertations

This dissertation introduces a holistic and systematic design methodology tailored to the 10 kV silicon carbide (SiC) MOSFET power modules to achieve multi-objective optimization with enhanced electric-field (E-field) distribution, minimized common-mode (CM) parasitic capacitance, and reduced system-level parasitic inductances. The proposed approach encompasses two innovative techniques: 1) an electric-potential-oriented module-system interface to reduce system-level parasitic inductance while maximizing insulation capability; 2) stacked substrates with patterned middle layer copper to alleviate the E-field concentration at the triple-point and reduce the maximum E-field without compromising on thermal resistance. The effectiveness of these innovative approaches is substantiated through the development of a 10 …

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Hierarchical Power Converter Physical Design, Tristan Mark Evans May 2024

Hierarchical Power Converter Physical Design, Tristan Mark Evans

Graduate Theses and Dissertations

The field of power electronics is undergoing rapid advancement that is driven by the need for further electrification in all aspects of power generation and transmission, transportation, and consumer goods. Recent advances in wide bandgap (WBG) semiconductor technologies continue to push their adoption in systems with higher power densities and conversion efficiencies. However, the way in which the components of these systems are designed has not kept pace with the rapidly evolving landscape of their applications and often requires costly, manual design iteration. Therefore, new methods are needed to improve this design process. Packaging of power devices is a critical …

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Spin Disorder Control Of Topological Spin Texture, Hongrui Zhang, Yu-Tsun Shao, Xiang Chen, Binhua Zhang, Tianye Wang, Fanhao Meng, Kun Xu, Peter Meisenheimer, Xianzhe Chen, Xiaoxi Huang, Piush Behera, Sajid Husain, Tiancong Zhu, Hao Pan, Yanli Jia, Nick Settineri, Nathan Giles-Donovan, Zehao He, Andreas Scholl, Alpha N'Diaye, Padraic Shafer, Archana Raja, Changsong Xu, Lane W. Martin, Michael F. Crommie, Jie Yao, Ziqiang Qiu, Arun Majumdar, Laurent Bellaiche, David A. Muller, Robert J. Birgeneau, Ramamoorthy Ramesh May 2024

Spin Disorder Control Of Topological Spin Texture, Hongrui Zhang, Yu-Tsun Shao, Xiang Chen, Binhua Zhang, Tianye Wang, Fanhao Meng, Kun Xu, Peter Meisenheimer, Xianzhe Chen, Xiaoxi Huang, Piush Behera, Sajid Husain, Tiancong Zhu, Hao Pan, Yanli Jia, Nick Settineri, Nathan Giles-Donovan, Zehao He, Andreas Scholl, Alpha N'Diaye, Padraic Shafer, Archana Raja, Changsong Xu, Lane W. Martin, Michael F. Crommie, Jie Yao, Ziqiang Qiu, Arun Majumdar, Laurent Bellaiche, David A. Muller, Robert J. Birgeneau, Ramamoorthy Ramesh

Physics Faculty Publications and Presentations

Stabilization of topological spin textures in layered magnets has the potential to drive the development of advanced low-dimensional spintronics devices. However, achieving reliable and flexible manipulation of the topological spin textures beyond skyrmion in a two-dimensional magnet system remains challenging. Here, we demonstrate the introduction of magnetic iron atoms between the van der Waals gap of a layered magnet, Fe3GaTe2, to modify local anisotropic magnetic interactions. Consequently, we present direct observations of the order-disorder skyrmion lattices transition. In addition, non-trivial topological solitons, such as skyrmioniums and skyrmion bags, are realized at room temperature. Our work highlights …

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High Bandwidth Hybrid Current Sensor Readout Interface For Power Applications, Asma Mahar May 2024

High Bandwidth Hybrid Current Sensor Readout Interface For Power Applications, Asma Mahar

Graduate Theses and Dissertations

High-density and power-efficient circuits have become realizable with the advent of wide bandgap semiconductor devices due to their high switching speed and lower conduction/switching losses. The operation of these circuits requires current information for protection, monitoring, and control. For the realization and a further boost in the efficiency of such power circuits, small size, non-invasive, high bandwidth current sensors with noise immunity, accuracy, and linearity are required. Various hybrid sensors have been reported to meet the requirements of emerging power circuits. A combination of a magneto resistor or Hall sensor and a coil is used to cover a wide frequency …

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High Performance Silicon Carbide Based Converters For Powertrain Electrification, Nan Lin May 2024

High Performance Silicon Carbide Based Converters For Powertrain Electrification, Nan Lin

Graduate Theses and Dissertations

With the increasing concern towards environment protection, electric vehicles (EVs) and hybrid electric vehicles (HEVs) have become popular in recent years. They not only help reduce carbon emissions, but also come with other benefits such higher efficiency and better user experience. Many countries and vehicle manufactures have made their plans to keep up with this trend in vehicle electrification. Powertrain is an assembly of components in a vehicle that pushes it forward. As for EVs and HEVs, their powertrains are composed of one or more power electronics converters, which are significant to the system. Silicon carbide MOSFETs have shown superior …

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Design And Implementation Of High-Frequency Dc-Dc Converters For Ev Applications, Rahul Biswash May 2024

Design And Implementation Of High-Frequency Dc-Dc Converters For Ev Applications, Rahul Biswash

Graduate Theses and Dissertations

The power electronics industry has been revolutionized by introducing wide bandgap semiconductor devices, such as Silicon Carbide (SiC) and Gallium Nitride (GaN). Due to their high frequency, high temperature, and high voltage operating capabilities, wide bandgap devices boast significant improvements in power density, efficiency, and reliability, as evidenced by their ability to decrease the size of power converters by operating at higher frequencies, temperatures and voltages, use of smaller and less passive components, such as transformers, inductors and capacitors, which makes power converters more compact and light-weight, ideal for space and weight-constrained applications, and compatibility with a wide range of …

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High-Power Dc-Dc Transformer For Medium-Voltage Grids With High-Voltage Sic Technology, Roderick Gomez May 2024

High-Power Dc-Dc Transformer For Medium-Voltage Grids With High-Voltage Sic Technology, Roderick Gomez

Graduate Theses and Dissertations

The objective of this dissertation is to present the theoretical analysis, design process, application and manufacturing of a proposed solid-state transformer intended for medium-voltage applications with minimal high-frequency oscillations. Galvanic isolation on medium-voltage DC-DC converters tend to employ large number of turns in the high voltage side of the transformers leading to non-negligible parasitic stray capacitances which form resonance tanks with the transformer inductances. Therefore, it is critical to estimate these parasitic capacitances to avoid severe high frequency oscillations which can significantly impact the converter performance. The main contribution of this thesis is the extension of a proposed custom-core design …

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The National Center For Reliable Electric Power Transmission Test Facility, Anna Corbitt, Wesley G. Schwartz, Chris Farnell, Juan Carlos Balda, H. Alan Mantooth May 2024

The National Center For Reliable Electric Power Transmission Test Facility, Anna Corbitt, Wesley G. Schwartz, Chris Farnell, Juan Carlos Balda, H. Alan Mantooth

Electrical Engineering and Computer Science Faculty Publications and Presentations

Globally, new technological solutions are being studied and developed by researchers in the field of power and energy systems. Before these solutions can be integrated into society as marketable products, thorough testing and validation of the design must be conducted. The National Center for Reliable Electric Power Transmission (NCREPT) is a unique high-power test facility located at the University of Arkansas, Fayetteville, AR, USA. NCREPT is a 12,000-square-foot laboratory space capable of testing power levels up to 6 MVA and offers testing at both the 480 V and 13.8 kV levels. NCREPT's capabilities expand outside of the scope of simply …

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Modeling, Characterization, And Machine Learning Algorithm For Rectangular Choke Horn Antennas, Ibrahim N. Alquaydheb, Saleh A. Alfawaz, Amirreza Ghadimi Avval, Sara Ghayouraneh, Samir M. El-Ghazaly Apr 2024

Modeling, Characterization, And Machine Learning Algorithm For Rectangular Choke Horn Antennas, Ibrahim N. Alquaydheb, Saleh A. Alfawaz, Amirreza Ghadimi Avval, Sara Ghayouraneh, Samir M. El-Ghazaly

Electrical Engineering and Computer Science Faculty Publications and Presentations

In this work, we present the design and modeling of a new type of choke horn antenna. It incorporates a rectangular waveguide and a rectangular choke acting as a parasitic element. The four-sided geometry of the antenna is applicable to systems that utilize rectangular waveguides. Also, it can overcome the need for rectangular-to-circular transition of transmission line or mode conversion. The main objective of this paper is to develop a model that calculates the far field radiation characteristics of the proposed antenna (analytical part) and to incorporate a finite element method (FEM) solver that adds to the theoretical solution (empirical …

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Aggregation And Oligomerization Characterization Of Ss-Lactoglobulin Protein Using A Solid-State Nanopore Sensor, Mitu C. Acharjee, Brad Ledden, Brian Thomas, Xianglan He, Troy Messina, Jason Giurleo, David Talaga, Jiali Li Jan 2024

Aggregation And Oligomerization Characterization Of Ss-Lactoglobulin Protein Using A Solid-State Nanopore Sensor, Mitu C. Acharjee, Brad Ledden, Brian Thomas, Xianglan He, Troy Messina, Jason Giurleo, David Talaga, Jiali Li

Physics Faculty Publications and Presentations

Protein aggregation is linked to many chronic and devastating neurodegenerative human diseases and is strongly associated with aging. This work demonstrates that protein aggregation and oligomerization can be evaluated by a solid-state nanopore method at the single molecule level. A silicon nitride nanopore sensor was used to characterize both the amyloidogenic and native-state oligomerization of a model protein ß-lactoglobulin variant A (βLGa). The findings from the nanopore measurements are validated against atomic force microscopy (AFM) and dynamic light scattering (DLS) data, comparing βLGa aggregation from the same samples at various stages. By calibrating with linear and circular dsDNA, this study …

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Ism-Band Energy Harvesting Wireless Sensor Node, Fnu Naveed Dec 2023

Ism-Band Energy Harvesting Wireless Sensor Node, Fnu Naveed

Graduate Theses and Dissertations

In recent years, the interest in remote wireless sensor networks has grown significantly, particularly with the rapid advancements in Internet of Things (IoT) technology. These networks find diverse applications, from inventory tracking to environmental monitoring. In remote areas where grid access is unavailable, wireless sensors are commonly powered by batteries, which imposes a constraint on their lifespan. However, with the emergence of wireless energy harvesting technologies, there is a transformative potential in addressing the power challenges faced by these sensors. By harnessing energy from the surrounding environment, such as solar, thermal, vibrational, or RF sources, these sensors can potentially operate …

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Characterization Of Highly Doped N-Type And P-Type Silicon Carbide Ohmic Contacts, Tanner Rice Dec 2023

Characterization Of Highly Doped N-Type And P-Type Silicon Carbide Ohmic Contacts, Tanner Rice

Graduate Theses and Dissertations

Silicon Carbide (SiC) is a rather new material that possesses unparalleled properties when compared to Silicon. Due to its larger band gap alongside other thermal properties, SiC can survive in hotter, more radiation intensive environments, whether that be within the crust of the earth or in the reaches of space. As a desirable semiconductor for these applications, CMOS is an especially important device due to its low power consumption. However, creating a good contact between the metal and semiconductor optimally requires two different metals for the n -type and the p-type semiconductor. This greatly increases the processing time, as separate …

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Design Of A Low-Power Delay-Locked Loop-Based 8x Frequency Multiplier In 22 Nm Fdsoi, Naveed, Jeff Dix Dec 2023

Design Of A Low-Power Delay-Locked Loop-Based 8x Frequency Multiplier In 22 Nm Fdsoi, Naveed, Jeff Dix

Electrical Engineering Faculty Publications and Presentations

A low-power delay-locked loop (DLL)-based frequency multiplier is presented. The multiplier is designed in 22 nm FDSOI and achieves 8× multiplication. The proposed DLL uses a new simple duty cycle correction circuit and is XOR logic-based for frequency multiplication. Current starved delay cells are used to make the circuit power efficient. The circuit uses three 2× stages instead of an edge combiner to achieve 8× multiplication, thus requiring far less power and chip area as compared to conventional phase-locked loop (PLL) circuits. The proposed 8× multiplier occupies an active area of 0.09 mm2. The measurement result shows ultra-low power consumption …

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Growth Of Germanium Thin Films On Sapphire Using Molecular Beam Epitaxy, Emmanuel Wangila, Peter Lytvyn, Hryhorii Stanchu, Calbi Gunder, Fernando Maia De Oliveira, Samir Saha, Subhashis Das, Niroshi Eldose, Chen Li, Mohammad Zamani-Alavijeh, Mourad Benamara, Yuriy I. Mazur, Shui-Qing Yu, Gregory J. Salamo Nov 2023

Growth Of Germanium Thin Films On Sapphire Using Molecular Beam Epitaxy, Emmanuel Wangila, Peter Lytvyn, Hryhorii Stanchu, Calbi Gunder, Fernando Maia De Oliveira, Samir Saha, Subhashis Das, Niroshi Eldose, Chen Li, Mohammad Zamani-Alavijeh, Mourad Benamara, Yuriy I. Mazur, Shui-Qing Yu, Gregory J. Salamo

Electrical Engineering Faculty Publications and Presentations

Germanium films were grown on c-plane sapphire with a 10 nm AlAs buffer layer using molecular beam epitaxy. The effects of Ge film thickness on the surface morphology and crystal structure were investigated using ex situ characterization techniques. The nucleation of Ge proceeds by forming (111) oriented three-dimensional islands with two rotational twin domains about the growth axis. The boundaries between the twin grains are the origin of the 0.2% strain and tilt grains. The transition to a single-grain orientation reduces the strain and results in a better-quality Ge buffer. Understanding the role of thickness on material quality during the …

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Study Of All-Group-Iv Sigesn Mid-Ir Lasers With Dual Wavelength Emission, Grey Abernathy, Solomon Ojo, Abdulla Said, Joshua M. Grant, Yiyin Zhou, Hryhorii Stanchu, Wei Du, Baohua Li, Shui-Qing Yu Oct 2023

Study Of All-Group-Iv Sigesn Mid-Ir Lasers With Dual Wavelength Emission, Grey Abernathy, Solomon Ojo, Abdulla Said, Joshua M. Grant, Yiyin Zhou, Hryhorii Stanchu, Wei Du, Baohua Li, Shui-Qing Yu

Electrical Engineering Faculty Publications and Presentations

Direct band gap GeSn alloys have recently emerged as promising lasing source materials for monolithic integration on Si substrate. In this work, optically pumped mid-infrared GeSn lasers were studied with the observation of dual-wavelength lasing at 2187 nm and 2460 nm. Two simultaneous lasing regions include a GeSn buffer layer (bulk) and a SiGeSn/GeSn multiple quantum well structure that were grown seamlessly using a chemical vapor deposition reactor. The onset of dual lasing occurs at 420 kW/cm2. The wider bandgap SiGeSn partitioning barrier enables the independent operation of two gain regions. While the better performance device in terms …

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Understanding Peripheral Blood Pressure Signals: A Statistical Learning Approach, Md Abul Hayat Aug 2023

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 …

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Fabrication And Measurement Of Lt-Gaas Photoconductive Antennas And Arrays, Zachary Paul Uttley Aug 2023

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 …

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Achieving High Renewable Energy Integration In Smart Grids With Machine Learning, Yaze Li Aug 2023

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. …

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Double-Sided Cooled Power Modules For Electric Vehicles, Riya Paul Aug 2023

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 …

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Partial Discharge Mitigation In Power Modules Using An Automation-Driven Design Rule Development Method, Shilpi Mukherjee Aug 2023

Partial Discharge Mitigation In Power Modules Using An Automation-Driven Design Rule Development Method, Shilpi Mukherjee

Graduate Theses and Dissertations

Power modules used for the conversion and conditioning of electrical power for applications like electric vehicles, more-electric aircraft, the power grid, etc., are largely designed manually by engineers. Design automation of power modules is starting to gain recognition as a timely and necessary alternative to intuitive manual design and fabrication. With increasing need for wide bandgap materials that can operate at higher voltages, and the need to make modules more compact, hazards like electrical breakdown are more likely. Partial discharge (PD) is a silent and invisible precursor to electrical breakdown. It is compounded with compaction, creating a potential for electrical …

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A Real-Time Anpc Inverter Digital Twin With Integrated Design-For-Trust, Paulo Vitor Do Amaral Custodio Aug 2023

A Real-Time Anpc Inverter Digital Twin With Integrated Design-For-Trust, Paulo Vitor Do Amaral Custodio

Graduate Theses and Dissertations

The demand for renewable energy has increased over the last few years, and so has the demand for greater expectations within the energy market. This increasing trend has been accompanied by more significant usage of internet-connected devices (IoT), leading to critical electrical infrastructure being connected to the internet. Implementing internet connectivity with such devices and systems provides benefits such as improving the system's performance, facilitating irregularity and anomaly mitigation, and providing additional situational awareness for enhanced decision-making. However, enhancing the connected system with IoT introduces a drawback – a greater vulnerability to cyber-attacks. Cyber-attacks targeting critical infrastructure in the electrical …

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