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Missouri University of Science and Technology

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Articles 1261 - 1290 of 21777

Full-Text Articles in Engineering

Human Arm Stiffness Estimation Method Developed For Overground Physical Interaction Experiments: Experimental Validation And Perspectives For Future Applications, Tarani Kanth Kamma Jan 2024

Human Arm Stiffness Estimation Method Developed For Overground Physical Interaction Experiments: Experimental Validation And Perspectives For Future Applications, Tarani Kanth Kamma

Masters Theses

"To build a physically interactive robot for overground applications, it is crucial to first understand the biomechanics of humans underlying overground physical human-robot interaction (pHRI) tasks. Estimating human arm stiffness during overground interactive tasks is a promising first step toward this goal. For this, an arm stiffness estimation technique was developed in our previous works that consider the unique challenges involving overground pHRI, such as the need to estimate the arm stiffness from a short duration of data with fewer repetitions. In this work, our stiffness estimation method is further validated with a passive spring setup with known stiffness values, …

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Computational Fluid Dynamics Analysis Of Thermal-Hydraulic Phenomena In Nuclear Reactor Systems, Mehedi Hasan Tusar Jan 2024

Computational Fluid Dynamics Analysis Of Thermal-Hydraulic Phenomena In Nuclear Reactor Systems, Mehedi Hasan Tusar

Masters Theses

"A computational analysis of thermal-hydraulic processes in nuclear reactor systems is performed, leveraging Computational Fluid Dynamics (CFD) to advance the design and ensure the safety of nuclear reactors. Divided into two primary sections, the initial part examines thermal-hydraulic behavior in the Replacement Research Reactor (RRR) operating at 20 megawatts and evaluates potential enhancements for the Missouri University of Science and Technology Reactor (MSTR) to operate at an increased capacity of 2 megawatts from the existing 0.2 megawatts. Detailed simulations reveal insights into flow characteristics, temperature distributions, and pressure drops, highlighting the effective use of realistic and porous media modeling techniques …

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Sub-Critical Crack Growth And Fatigue Behaviour Of Alkali Silicate Glass, Noah Weyrauch Jan 2024

Sub-Critical Crack Growth And Fatigue Behaviour Of Alkali Silicate Glass, Noah Weyrauch

Masters Theses

"Delayed failure in silicate glasses can be linked to subcritical crack growth (SCCG) where surface defects grow over time until catastrophic failure. This phenomenon originates from stress-enhanced chemical interactions between the environment (e.g. water) and the strained silicate bonds at the crack tip. SCCG must be accounted for to predict the long-term survivability of silicate-glass components. This study compares two methods to measure SCCG parameters for a commercial alkali silicate sealing glass and for a series of binary xNa2O-(1-x)SiO2 glasses, where 0.15 ≤ x ≤ 0.35. A constant moment double cantilever beam (DCB) technique was used to …

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In Situ High Temperature Fiber-Optic Raman Sensor For Industrial Applications, Bohong Zhang Jan 2024

In Situ High Temperature Fiber-Optic Raman Sensor For Industrial Applications, Bohong Zhang

Doctoral Dissertations

"Continuous casting in steel production uses specially developed oxyfluoride glasses (mold fluxes) to lubricate a mold and control the solidification of the steel in the mold. The composition of the flux impacts properties, including basicity, viscosity, and crystallization rate, all of which affect the stability of the casting process and the quality of the solidified steel. However, mold fluxes interact with steel during the casting process, resulting in flux chemistry changes that must be considered in the flux design. Currently, the chemical composition of mold flux must be determined by extracting flux samples from the mold during casting and then …

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Design And Development Of Biocompatible Mofs And Silica-Based Nanocarriers With Controlled Pharmacokinetics For Drug Delivery Applications, Neila Pederneira Jan 2024

Design And Development Of Biocompatible Mofs And Silica-Based Nanocarriers With Controlled Pharmacokinetics For Drug Delivery Applications, Neila Pederneira

Doctoral Dissertations

"In the past decade, a big interest has drawn into nanoporous metal-organic frameworks (MOFs) and silica-based materials as nanocarriers for drug delivery applications, owing to their exceptionally high surface area and highly structured porous network. The overall goal of this research was to optimize the pharmacokinetic behavior of several highly porous biocompatible drug carriers that have the potential to carry Ibuprofen, 5-Fluorouracil, and Curcumin to the desired tissue without creating a burst effect and minimizing the amount of dosage and size that conventional capsules require. The specific objectives of this study are to (i) assess the effect of drug solubility …

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Improving Decision-Making Processes In Construction And Infrastructure Bidding: Qualitative And Quantitative Approaches Including Graph Theory, Game Theory, And Machine Learning, Muaz Osman Elzubeir Ahmed Jan 2024

Improving Decision-Making Processes In Construction And Infrastructure Bidding: Qualitative And Quantitative Approaches Including Graph Theory, Game Theory, And Machine Learning, Muaz Osman Elzubeir Ahmed

Doctoral Dissertations

"Construction and infrastructure bidding is a highly competitive process that entails various uncertainties faced by contractors. Contractors weigh various factors to determine the expected benefits of a construction project and decide their bid value. However, the situation is more complex in multi-stage bidding (MSG), where general contractors must account for the bids of their subcontractors and face a greater threat of the winner’s curse (i.e., situation where the winning contractor underestimates the actual cost of the project). As such, bidding-related complexities, risks, and uncertainties, if uncontrolled, can lead to the rise of claims and disputes between stakeholders. Existing research falls …

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In-Depth Characterization Of The Selective Oxidation Products Of Hafnium Carbide, Jonathan Allen Scott Jan 2024

In-Depth Characterization Of The Selective Oxidation Products Of Hafnium Carbide, Jonathan Allen Scott

Doctoral Dissertations

"Materials capable of withstanding oxidative environments at temperatures >2000°C are necessary for hypersonic applications. Hafnium carbide (HfC) shows a combination of properties that lends itself toward these applications; however, its oxidation behavior is poorly understood. At 1300°C, HfC was found to oxidize via the following mechanism: 1) Initial oxidation of both C and Hf present in the system, 2) Formation of an interconnected pore network, whose size is related to the volume of gases being generated during the oxidation process, 3) Growth of the oxide scale to become sufficiently protective, 4) Formation of an initially amorphous “HfO2C” at …

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Pseudo-Three-Dimensional Back-Analysis Of Rainfall-Induced Landslides In Utuado, Puerto Rico, Mirna Kassem, Weibing Gong, Dimitrios Zekkos, Marin Clark, Stephen Hughes Jan 2024

Pseudo-Three-Dimensional Back-Analysis Of Rainfall-Induced Landslides In Utuado, Puerto Rico, Mirna Kassem, Weibing Gong, Dimitrios Zekkos, Marin Clark, Stephen Hughes

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Regional slope stability analyses can provide a system-level assessment of landslide susceptibility. This study aims to develop a regional back-analysis model for rainfall-induced landslides to compute ground shear strength that can be used for landslide prediction. Most commonly, mechanistic-based models for regional slope stability consist of simplified one-dimensional (1D) analyses compared to more realistic three-dimensional (3D) procedures. A pseudo-3D methodology is applied on 788 landslides over two 2.5 km2 areas in the plutonic rocks of the Utuado Batholith. First, an infinite slope stability triggering model is applied on a 1 m-resolution digital elevation model (DEM) to identify the triggering grid …

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Experimental Study: Evaluating The Effect Of Low High Viscosity Friction Reducer Concentrations To Transport Proppant Across Static And Dynamic Models, Ghith Biheri, Abdulmohsin Imqam, Shari Dunn-Norman, Khaled Elmaleh Jan 2024

Experimental Study: Evaluating The Effect Of Low High Viscosity Friction Reducer Concentrations To Transport Proppant Across Static And Dynamic Models, Ghith Biheri, Abdulmohsin Imqam, Shari Dunn-Norman, Khaled Elmaleh

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Hydraulic fracturing treatments may significantly improve the oil production from wells in unconventional reservoirs by enhancing the fracture conductivities. Fracture conductivity can be improved by efficiently transporting and distributing the proppant through the lengths of the fractures. The main target of this study is to evaluate the viscosity and elasticity of high viscosity friction reducer (HVFR) for the purpose of transport and suspend the proppant at a temperature of 25°C. This study an alyzes the settling of proppant across HVFR using two different concentrations, 0.5 and 1 gallon per thousand of gallon (gpt). The tests were conducted using two static …

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Evaluating Friction Characteristics Of High Friction Surface Treatment Application Under Varied Polishing And Slippery Conditions, Alireza Roshan, Magdy Abdelrahman Jan 2024

Evaluating Friction Characteristics Of High Friction Surface Treatment Application Under Varied Polishing And Slippery Conditions, Alireza Roshan, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The frictional attributes of high friction surface treatment (HFST) play a crucial role in ensuring optimal traffic safety, particularly in wet weather conditions. Friction consists of two important components: adhesion and hysteresis. This research focuses on evaluating these essential factors in HFST using two different aggregates and two distinct sizes by considering various abrasion and polishing methods. To isolate these components for assessment, testing was carried out under various slippery conditions, including dry, wet with water, and wet with water + soap. The inclusion of liquid hand soap in the test procedure effectively minimized or even eliminated the adhesion component's …

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A Review Of Dielectric Barrier Discharge Cold Atmospheric Plasma For Surface Sterilization And Decontamination, Kolawole Adesina, Ta Chun Lin, Yue-Wern Huang, Marek Locmelis, Daoru Frank Han Jan 2024

A Review Of Dielectric Barrier Discharge Cold Atmospheric Plasma For Surface Sterilization And Decontamination, Kolawole Adesina, Ta Chun Lin, Yue-Wern Huang, Marek Locmelis, Daoru Frank Han

Biological Sciences Faculty Research & Creative Works

Numerous investigations have shown that non-equilibrium discharges at atmospheric pressure, also known as "cold atmospheric plasma" (CAP) are efficient to remove biological contaminants from surfaces of a variety of materials. Recently, CAP has quickly advanced as a technique for microbial cleaning, wound healing, and cancer therapy due to the chemical and biologically active radicals it produces, known collectively as reactive oxygen and nitrogen species (RONS). This article reviews studies pertaining to one of the atmospheric plasma sources known as Dielectric Barrier Discharge (DBD) which has been widely used to treat materials with microbes for sterilization, disinfection, and decontamination purposes. To …

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In Vitro Assessment Of The Anti-Biofilm Effectiveness Of Copper And Zinc Enhanced Borate Bioactive Glass Using Processed Microscopic Images, Sarah Fakher, David J. Westenberg Jan 2024

In Vitro Assessment Of The Anti-Biofilm Effectiveness Of Copper And Zinc Enhanced Borate Bioactive Glass Using Processed Microscopic Images, Sarah Fakher, David J. Westenberg

Biological Sciences Faculty Research & Creative Works

The escalating burden of nosocomial infections presents a formidable challenge to healthcare systems worldwide, leading to increased morbidity, prolonged hospital stays, and elevated healthcare costs. These infections are often resistant to conventional antibiotic therapies due to their association with biofilms which contribute to the persistence and resistance of pathogens. In addressing the challenge of biofilm-associated nosocomial infections, borate bioactive glasses (BBGs) have emerged as promising biomaterials. Doping these glasses with antimicrobial metals could potentially harness their antibacterial properties to prevent biofilm formation. This study undertakes a rigorous evaluation of the anti-biofilm efficacy of copper and zinc-doped BBGs by employing processed …

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Advanced Detection Of Sars-Cov-2 And Omicron Variants Via Mxene-Graphene Hybrid Biosensors Utilizing Nucleic Acid Probes, Jiaoli Li, Yuwei Zhang, Congjie Wei, Yanxiao Li, Zhekun Peng, Hsin Yin Chuang, Logan Pearce, Adrianus Boon, Yue-Wern Huang, Dong Hyun Kim, Risheng Wang, Chenglin Wu Jan 2024

Advanced Detection Of Sars-Cov-2 And Omicron Variants Via Mxene-Graphene Hybrid Biosensors Utilizing Nucleic Acid Probes, Jiaoli Li, Yuwei Zhang, Congjie Wei, Yanxiao Li, Zhekun Peng, Hsin Yin Chuang, Logan Pearce, Adrianus Boon, Yue-Wern Huang, Dong Hyun Kim, Risheng Wang, Chenglin Wu

Biological Sciences Faculty Research & Creative Works

Low-cost biosensors that can rapidly and widely detect viruses are critical for faster diagnosis and treatment decision-making, especially for infections. The commonly used field-effect transistor is sensitive to the biomarker's detection but struggles with precise detection, particularly of nontargets such as ions and proteins. To overcome this limitation, we developed a field-effect transistor biosensor design based on MXene-graphene materials to increase the accuracy and sensitivity of virus detection. Based on the hybridization process between two complementary DNA strands, single-stranded nucleic acids were immobilized on the sensing surface via 3-aminopropyltriethoxysilane and glutaraldehyde to capture the nucleic acids of the target virus. …

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Agent-Based Modeling For Understanding Incentives Associated With Distributed Solar Generation, Gasser Ali, Islam H. El-Adaway Jan 2024

Agent-Based Modeling For Understanding Incentives Associated With Distributed Solar Generation, Gasser Ali, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Distributed solar generation (DSG), such as residential photo-voltaic (PV) solar panels, offers many benefits to consumers and can improve the sustainability and resilience of the electric power infrastructure. As such, many local and national authorities implemented policy incentives, such as rebates and loans with reduced interests, to promote the adoption of DSG. However, the increasing penetration of DSG is creating new obstacles for system operators due to the uncertainty in forecasting electrical power demand. There is a need to investigate how incentives affect DSG adoption. To achieve that goal, a complex system-of-systems (SoS) model is developed using agent-based modeling (ABM). …

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System Dynamics Modeling For Investigating The Retention Of Skilled Labor In The Construction Market, Tamima Elbashbishy, Islam H. El-Adaway Jan 2024

System Dynamics Modeling For Investigating The Retention Of Skilled Labor In The Construction Market, Tamima Elbashbishy, Islam H. El-Adaway

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Limited skilled labor has been one of the greatest challenges facing the construction industry, especially after COVID. In 2019, around 80% of contractors in the US reported problems in hiring enough skilled workers. Labor retention has been one of the major contributors to skilled labor shortages in construction. The goal of this paper is to study the impact of key construction industry characteristics and economic conditions on skilled labor shortages. This goal is achieved by simulating the flow of skilled workers throughout the construction industry. To this end, a system dynamics (SD) model was developed to represent skilled labor and …

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Investigating Price Fluctuation Transmission Among Construction Materials, Mohamad Abdul Nabi, Islam H. El-Adaway, Rayan H. Assaad Jan 2024

Investigating Price Fluctuation Transmission Among Construction Materials, Mohamad Abdul Nabi, Islam H. El-Adaway, Rayan H. Assaad

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Generally, Fluctuation In One Material's Price Can Cause A Series Of Chain Reactions In The Supply Chain System, Known As Price Fluctuation Transmission, As All Materials Are Interconnected And Interrelated. None Of The Previous Studies Have Investigated Price Fluctuation Transmission Among All Construction Materials. This Paper Aims To Fill This Gap In Knowledge. The Authors Collected Producer Price Index (PPI) Data For 16 Construction Materials, Modeled The Relationship Between Each Pair Of Materials Using Vector Autoregression Technique, And Validated The Causality Using Granger Causality Test. Network Analysis Was Performed To Identify The Price Fluctuation Transmission Capacity, Susceptibility, And Intermediatory Capacity …

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Analytical Modeling Of Partially-Filled Tm010-Mode Dielectric Resonator For Accurate Dk And Df Extraction, Mehdi Mousavi, Chaofeng Li, Reza Asadi, Seyedmostafa Mousavi, Reza Vahdani, Xiaoning Ye, Mina Esmaeelpour, Donghyun Kim Jan 2024

Analytical Modeling Of Partially-Filled Tm010-Mode Dielectric Resonator For Accurate Dk And Df Extraction, Mehdi Mousavi, Chaofeng Li, Reza Asadi, Seyedmostafa Mousavi, Reza Vahdani, Xiaoning Ye, Mina Esmaeelpour, Donghyun Kim

Electrical and Computer Engineering Faculty Research & Creative Works

In high-speed printed circuit board (PCB) modeling, the accurate determination of the dielectric constant (DK) and dissipation factor (DF) is crucial for signal integrity analysis at design stage. This paper introduces an analytical approach using a partially filled TM010-mode dielectric resonator, an effective tool for DK and DF extraction of PCB material. We begin by discussing the theoretical underpinnings of TM010-mode dielectric resonators and their applicability in measuring the DK and DF of the material under test. A mathematical model is then presented, linking the resonant characteristics directly to the DK and DF of the dielectric material. The …

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Frequency Division Multiplexing And Random Phasing For Improved Uniformity In Microwave Heating Applications, Logan M. Wilcox, Ali Mirala, Mohammad Tayeb Al Qaseer, Kristen M. Donnell Jan 2024

Frequency Division Multiplexing And Random Phasing For Improved Uniformity In Microwave Heating Applications, Logan M. Wilcox, Ali Mirala, Mohammad Tayeb Al Qaseer, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Microwave heating has been recently used as an active thermal excitation method in thermography. Within the nondestructive testing and evaluation (NDT&E) realm, this method is referred to as active microwave thermography, or AMT. In AMT, unlike other thermal excitation methods utilized in thermography, microwave heating inherently provides a nonuniform heating pattern. This is a direct result of the radiating antenna used to deliver the energy. This nonuniform pattern may result in defect detection errors (i.e., false positives and/or negatives). To reduce this potential for detection error and improve the overall robustness of the technique, a new electromagnetic system, consisting of …

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Additively Manufactured Aperture-Based Fss, Alexander Hook, Doyle T. Motes, Cody Morrow, Kristen M. Donnell Jan 2024

Additively Manufactured Aperture-Based Fss, Alexander Hook, Doyle T. Motes, Cody Morrow, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Frequency selective surfaces (FSSs) are arrays of patch- or aperture-based elements with specific high frequency reflective and/or transmissive properties. The specific FSS response of a given design is dictated by the element dimensions and spacing relative to adjacent elements (collectively referred to as the unit cell), along with the substrate (and superstrate if applicable) properties. As it relates to sensing, the FSS response may be affected by environmental (e.g., temperature) or structural (e.g., strain) changes. To this end, FSS-based sensors have been considered in recent years for a myriad of sensing applications including structural health monitoring (SHM). Concurrent to this, …

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Empowering Urban Traffic Management: Elevated 3d Lidar For Data Collection And Advanced Object Detection Analysis, Nawfal Guefrachi, Hakim Ghazzai, Ahmad Alsharoa Jan 2024

Empowering Urban Traffic Management: Elevated 3d Lidar For Data Collection And Advanced Object Detection Analysis, Nawfal Guefrachi, Hakim Ghazzai, Ahmad Alsharoa

Electrical and Computer Engineering Faculty Research & Creative Works

The 3D object detection capabilities in urban environments have been enormously improved by recent developments in Light Detection and Range (LiDAR) technology. This paper presents a novel framework that transforms the detection and analysis of 3D objects in traffic scenarios by utilizing the power of elevated LiDAR sensors. We are presenting our methodology's remarkable capacity to collect complex 3D point cloud data, which allows us to accurately and in detail capture the dynamics of urban traffic. Due to the limitation in obtaining real-world traffic datasets, we utilize the simulator to generate 3D point cloud for specific scenarios. To support our …

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Angle-Dependent Photoinduced Changes Of Near-Infrared Transmission In Amorphous Selenium Films, Kaitlin Hellier, Emily Enlow, Seyedehnajmeh Montazeri, Mina Esmaeelpour, Shiva Abbaszadeh Jan 2024

Angle-Dependent Photoinduced Changes Of Near-Infrared Transmission In Amorphous Selenium Films, Kaitlin Hellier, Emily Enlow, Seyedehnajmeh Montazeri, Mina Esmaeelpour, Shiva Abbaszadeh

Electrical and Computer Engineering Faculty Research & Creative Works

Amorphous selenium (a-Se) is a promising semiconductor for a variety of photoconductive applications, predominantly in X-ray detection. In addition, material properties introduce several other potential applications in nonlinear optics. Photodarkening (PD) presents an interesting area of study; when exposed to band-region light, metastable structural changes induce a shift in the band edge and increase tail absorption. In this work, we investigate these effects utilizing a near-infrared (NIR) probe to avoid generating any darkening during beam transmission. We observe an unexpected result; here, we present the effects of band region exposure in NIR transmission (1570 nm). We observe a shift from …

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Reinforcement Learning-Based Constrained Optimal Control Of Strict-Feedback Nonlinear Systems: Application To Autonomous Underwater Vehicles, Behzad Farzanegan, S. Jagannathan Jan 2024

Reinforcement Learning-Based Constrained Optimal Control Of Strict-Feedback Nonlinear Systems: Application To Autonomous Underwater Vehicles, Behzad Farzanegan, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper addresses a constrained neural network (NN)-based optimal tracking scheme for a class of uncertain nonlinear discrete-time systems in strict-feedback form by using a control barrier function (CBF). First, a modified barrier-type cost function is introduced for each subsystem, guiding the actual system trajectory toward the safe set or desired trajectory while avoiding unwanted sets. To address the tracking problem, an augmented system is employed to convert the time-varying optimal tracking to a time-invariant optimal regulation. Then, an actor-critic framework is employed with the backstepping technique to obtain both virtual and actual optimal control policies for each subsystem to …

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Tightening Qc Relaxations Of Ac Optimal Power Flow Through Improved Linear Convex Envelopes, Mohammad Rasoul Narimani, Daniel K. Molzahn, Katherine R. Davis, Mariesa L. Crow Jan 2024

Tightening Qc Relaxations Of Ac Optimal Power Flow Through Improved Linear Convex Envelopes, Mohammad Rasoul Narimani, Daniel K. Molzahn, Katherine R. Davis, Mariesa L. Crow

Electrical and Computer Engineering Faculty Research & Creative Works

AC optimal power flow (AC OPF) is a fundamental problem in power system operations. Accurately modeling the network physics via the AC power flow equations makes AC OPF a challenging nonconvex problem. To search for global optima, recent research has developed various convex relaxations that bound the optimal objective values of AC OPF problems. The QC relaxation convexifies the AC OPF problem by enclosing the non-convex terms within convex envelopes. The QC relaxation's accuracy strongly depends on the tightness of these envelopes. This paper proposes two improvements for tightening QC relaxations of OPF problems. We first consider a particular nonlinear …

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Effect Of Signal Modulation On Active Microwave Thermography, Logan M. Wilcox, Mathias Bonmarin, Kristen M. Donnell Jan 2024

Effect Of Signal Modulation On Active Microwave Thermography, Logan M. Wilcox, Mathias Bonmarin, Kristen M. Donnell

Electrical and Computer Engineering Faculty Research & Creative Works

Active microwave thermography (AMT) is a coupled electromagnetic and thermographic nondestructive testing and evaluation (NDT&E) technique. AMT utilizes an active electromagnetic source to induce heat on or within a specimen under test (SUT) with subsequential infrared measurements via an infrared camera. AMT has been successfully employed in multiple fields, including aerospace, space, and infrastructure, among others. Generally, for AMT, the excitation (electromagnetic source) is applied over a specified period of time (referred to as the heating time). If inspection continues for additional time after the excitation is removed (turned off), this period is referred to as the cooling time. This …

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Visualization Of Noise Coupling Paths Based On The Reciprocity Theorem, Seungtaek Jeong, Jong Hwa Kwon, Deepak Pai, Jagan Rajagopalan, Chulsoon Hwang Jan 2024

Visualization Of Noise Coupling Paths Based On The Reciprocity Theorem, Seungtaek Jeong, Jong Hwa Kwon, Deepak Pai, Jagan Rajagopalan, Chulsoon Hwang

Electrical and Computer Engineering Faculty Research & Creative Works

In this article, visualization of noise coupling paths is proposed and verified. The coupling coefficient (CC) is derived based on the Reciprocity theorem and time-average coupled power, which represents the contribution of each spatial point to the coupled power. The physical meaning of CC is demonstrated by relating the integrations of CC in a volume space occupied by absorbers to the coupled power being suppressed by the absorbers. The proposed method is applied to a practical device and the identified dominant coupling paths are experimentally verified.

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Simultaneous Frequency Regulation And Active Power Sharing In Islanded Microgrid Using Deep Reinforcement Learning, Oroghene Oboreh-Snapps, Sophia A. Strathman, Jonathan Saelens, Arnold Fernandes, Lauryn Morris, Praneeth Uddarraju, Jonathan W. Kimball Jan 2024

Simultaneous Frequency Regulation And Active Power Sharing In Islanded Microgrid Using Deep Reinforcement Learning, Oroghene Oboreh-Snapps, Sophia A. Strathman, Jonathan Saelens, Arnold Fernandes, Lauryn Morris, Praneeth Uddarraju, Jonathan W. Kimball

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel approach that integrates deep reinforcement learning (DRL) with the conventional virtual synchronous generator (VSG) to address dual objectives of microgrid (MG) control, frequency regulation and precise active power sharing. MGs typically consist of multiple Inverter-Based-Distributed-Generators (IBDGs) connected in parallel through different line impedances. The conventional active power loop (APL) of the VSG encounters significant steady-state frequency errors as load increases/decreases during islanded operation. To mitigate this issue, secondary-level controllers like proportional-integral (PI) control are added to the APL to regulate the frequency of IBDGs. However, PI control compromises power-sharing capabilities when the impedance values of …

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Tilted Fiber Bragg Grating Sensors Based On Time-Domain Measurements With Microwave Photonics, Shiyu Li, Ruimin Jie, Osamah Alsalman, Jie Huang, Chen Zhu Jan 2024

Tilted Fiber Bragg Grating Sensors Based On Time-Domain Measurements With Microwave Photonics, Shiyu Li, Ruimin Jie, Osamah Alsalman, Jie Huang, Chen Zhu

Electrical and Computer Engineering Faculty Research & Creative Works

Tilted fiber Bragg gratings (TFBGs) have garnered substantial research attention and have found widespread applications for sensing a diverse array of physical, chemical, and biological parameters based on optical spectrum measurements. The interrogation of a TFBG sensor typically requires a high-resolution bulky optical spectrum analyzer (OSA) due to the extremely narrow dips caused by the resonance of cladding modes. However, high-resolution OSAs can be costly and have limitations on measuring speed, limiting their practicality. In this paper, a new approach to interrogating TFBG sensors is proposed and experimentally demonstrated based on a microwave photonics technique. Instead of measuring the optical …

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An Equivalent Coil Model Of A Wireless Power Transfer System Including Eddy Loss, Hanyu Zhang, Daryl G. Beetner Jan 2024

An Equivalent Coil Model Of A Wireless Power Transfer System Including Eddy Loss, Hanyu Zhang, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

A wireless power transfer (WPT) system suffers from eddy loss if a conductive object is placed near the coupling coil. In this paper, a 3-coil equivalent circuit model for the coupling coil in a WPT system is proposed for analyzing the eddy loss due to nearby conductors. This model uses a third coil with inductive coupling to the original transmitting and receiving coils to model the eddy loss. The proposed model was validated by comparing the Z-parameters with a full-wave simulation and showing good correlation over the frequency of interest, where the traditional 2-coil model fails. The 3-coil model is …

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Evaluation Of Transfer Learning Models On Traumatic Brain Injury Severity Classification, Ngoc Do, Daniel B. Hier, Tayo Obafemi-Ajayi Jan 2024

Evaluation Of Transfer Learning Models On Traumatic Brain Injury Severity Classification, Ngoc Do, Daniel B. Hier, Tayo Obafemi-Ajayi

Electrical and Computer Engineering Faculty Research & Creative Works

After traumatic brain injury (TBI), clinicians use the Glasgow Coma Scale (GCS) to classify patients by severity and radiologists use the Rotterdam score and the Marshall score to classify CT scans by severity. This work investigates a viable efficient low-cost transfer learning model to use MRI images to predict GCS, Rotterdam, and Marshall severity class after TBI. The enhanced transfer learning model architecture integrates multiple fine-tuning steps in which a few layers of the pre-trained model is unfrozen in each iteration so that the neural network is able to learn layer by layer further aspects of the image for better …

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Influence Of Variations In Imbalanced Lisn Termination Impedances On Radiated Emissions, Hossein Rezaei, Morten Sørensen, Kim Jensen, David Pommerenke, Daryl G. Beetner Jan 2024

Influence Of Variations In Imbalanced Lisn Termination Impedances On Radiated Emissions, Hossein Rezaei, Morten Sørensen, Kim Jensen, David Pommerenke, Daryl G. Beetner

Electrical and Computer Engineering Faculty Research & Creative Works

Radiated emissions measurements are often performed using a line impedance stabilization network (LISN) with a balanced termination, but in the real-world the common-mode characteristic of the termination may be highly variable. An asymmetric LISN allows testing under more realistic asymmetric termination conditions. The common-mode termination impedance of these LISNs must fall within set tolerances, but the impact of these tolerances is unknown. An analysis of the radiated emissions from a device under test (DUT) for a wide variety of power cable termination impedances is performed in the following paper to estimate the impact of allowed variations in imbalanced LISN termination …

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