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Microwave, Antennas & Circuits (ICMAC), International Conference on

作者： Asadullah Muhammad U. Khan Nosherwan Shoaib Ali Ahmed Atef A. Aburas Abdulkarim AlDabbagh Anas M. A. Saleh School of Electrical Engineering and Computer Science (SEECS) National University of Sciences and Technology (NUST) Islamabad Pakistan Telecom R&D Department Advanced Communications & Electronics Systems (ACES) Riyadh Kingdom of Saudi Arabia

ISBN: (数字)9798331518424

ISBN: (纸本)9798331518431

A 4-element hybrid MIMO antenna is presented for O-RAN compliant 5G small cell radio unit. The antenna design consists of U-shaped microstrip radiator elements which are designed to operate in FR1 band having impedance bandwidth of 2.16-4.5 GHz. A partial cylindrical DRA is integrated with the U-shaped microstrip for the FR2 band resonance having impedance bandwidth of 20.8 - 29.55 GHz. MIMO antenna elements are rotated 90° and placed in square arrangement resulting in the overall size of 72.12mm x 72.12mm making this antenna easily coalescent with the RFFE module of the Open RU. The antenna has a peak gain of 1.42 dB on the FR1 band and 3 dB in the FR2 band. The antenna offers omni-directional radiation characteristics making it suitable for small cell applications for both indoor as well as outdoor implementation.

关键词： Wireless LAN 5G mobile communication Resonant frequency Open RAN Microstrip antennas Bandwidth Microstrip components Resonance Impedance Gain

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Recurrent Graph Neural Network-Based Identification of Replay Attacks in Power Networks

Recurrent Graph Neural Network-Based Identification of Repla...

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electrical, computer, Communications and Mechatronics engineering (ICECCME), International Conference on

作者： Faaiz Joad Rachad Atat Hayat Mbayed Abdulrahman Takiddin Dept. of Electrical & Computer Engineering Florida State University Tallahassee FL USA Computer Science Department Lebanese American University Beirut Lebanon Center for Advanced Power Systems Florida State University Tallahassee FL USA

ISBN: (数字)9798350391183

ISBN: (纸本)9798350391190

As cyber-physical systems, power networks exchange data to ensure smooth operation. Through communication networks, the exchanged data becomes vulnerable to cyberattacks where malicious entities establish malevolent connections to falsify the data, which exploit the data integrity, leading to network instability. Machine learning-based solutions have been proposed to identify such malevolent actions, including false data injection attacks. This paper aims to (a) enhance the attack detection performance and (b) quantify the performance of non-recurrent and recurrent machine learning-based attack detection systems against multiple replay attacks that involve falsifying data via presenting normal operation patterns from previous timestamps. It turns out that capturing temporal aspects from the data using recurrent models outperforms non-recurrent models by 5-32% in accuracy (ACC). Specifically, we propose a recurrent graph neural network (RGNN) model that captures the temporal and spatial aspects of the network data. The RGNN model outperforms non-recurrent models by 14 – 32% and other recurrent models by 6 – 13% in ACC. The experiments are conducted on IEEE 14, 39, and 118-bus power networks where the model performance is enhanced (by up to 8% in ACC) in larger systems due to capturing more spatial and temporal features.

关键词： Mechatronics Accuracy Data integrity Computational modeling Cyber-physical systems Data models Graph neural networks Communication networks computer crime

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Robust Control for a Class of Nonlinearly Coupled Hierarchical systems with Actuator Faults

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IFAC-PapersOnLine 2021年第20期54卷 540-546页

作者： Sina Ameli Olugbenga Moses Anubi Department of Electrical and Computer Engineering Florida State University Department of Electrical and Computer Engineering the Center for Advanced Power Systems Florida State University USA

This paper proposes an approach to addresses the control challenges posed by a fault-induced uncertainty in both the dynamics and control input effectiveness of a class of hierarchical nonlinear systems in which the high-level dynamics is nonlinearly coupled with a multi-agent low-level dynamics. The high-level dynamics has a multiplicative uncertainty in the control input effectiveness and is subjected to an exogenous disturbance input. On the other hand, the low-level system is subjected to actuator faults causing a time-varying multiplicative uncertainty in the dynamical model and associated control effectiveness. Moreover, the nonlinear coupling between the high-level and the low-level dynamics makes the problem even more challenging. To address this problem, an online parameter estimation algorithm is designed, coupled with an adaptive splitting mechanism which automatically distributes the control action among low level multi-agent systems. A nonlinear L 2 -gain-based controller, and then a state-feedback controller are designed in the high-level, and the low-level, respectively, to recover the system from faults with high performance in the transient response, and reject the exogenous disturbance. The resulting analysis guarantees a robust tracking of the high-level reference command signal.

关键词： Robust control applications system identification adaptive control of distributed parameter systems backstepping control of distributed parameter systems hierarchical multilevel multilayer control stability of nonlinear systems

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A Comprehensive Review of Partial Discharge Modeling and Measurement in WBG-based AC Machine Drives

A Comprehensive Review of Partial Discharge Modeling and Mea...

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IEEE Transportation Electrification Conference and Expo (ITEC)

作者： Kangbeen Lee Mostafa Fereydoonian Mohamad Saleh Sanjari Nia Woongkul Lee Department of Electrical and Computer Engineering Michigan State University East Lansing USA Advanced Systems Innovation Electric Drives BorgWarner Inc. Auburn Hills USA

This paper provides a comprehensive review of partial discharge (PD) in wide bandgap power switching device-based AC machine drives with high slew rate voltage pulses including advanced analytical PD models, measurement and detection techniques, and experimental setups. This review study finds that high voltage, and high switching systems make the electric drive insulation system vulnerable to PD and this phenomenon is likely to occur in the first few turns of electric machines. Partial discharge inception voltage (PDIV) trends with drive parameters (i.e., DC-link voltage, slew rate, cable length, and switching frequency) and environmental parameters (i.e., pressure, temperature, humidity, and contamination) were also investigated and summarized. PD models and analysis methods are also discussed from the capacitive model to an analytical model that accounts for high-frequency phenomena (such as overshoot and ringing voltage at the terminal) and uneven voltage distribution. Moreover, this paper summarizes the specifications of conducted, radiated, and acoustic measurement methods and addresses new challenges and opportunities in PD measurement. Additionally, both conventional experimental setups and newly proposed experimental setups for capturing full-frequency spectra of PD using the existing measurement methods are reviewed.

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A 0.9–1.4-GHz Q-Enhanced CMOS Tunable Bandpass Filter With Constant Fractional Bandwidth and Two Transmission Zeros

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IEEE Microwave and Wireless Technology Letters 2023年第6期33卷 667-670页

作者： Kun Li Xiang Li Shuangyang Wu Pei-Ling Chi Tao Yang School of Electronic Science and Engineering University of Electronic Science and Technology of China Chengdu China Research Center of Advanced RF Chips and Systems Nanhu Laboratory Jiaxing China Department of Electrical and Computer Engineering National Chiao Tung University Hsinchu Taiwan

A tunable differential $Q$ -enhanced bandpass filter covering 0.9–1.4 GHz with constant fractional bandwidth (FBW) is proposed using 40-nm CMOS technology in this letter. The proposed filter is constructed by two resonators which consist of ON-chip integrated inductors and varactors. The inductors of the two resonators are placed close to each other to form the mainline magnetic coupling of the filter. Besides the mainline coupling, the source port and load port are connected directly by capacitors, forming the source-to-load coupling. With the proposed structure, two transmission zeros (TZs) can be obtained, which can greatly increase the stopband rejection. Meanwhile, nMOS cross-coupled pairs are used as the $Q$ -enhanced cells to reduce the insertion loss (IL) and further improve the filter selectivity. A filter prototype based on 40-nm CMOS process is fabricated to validate the proposed structure. The center frequency (CF) of the proposed filter can be tuned from 0.9 to 1.4 GHz while keeping the FBW constant at 8%.

关键词： Resonator filters Band-pass filters Microwave filters Filtering theory Couplings Equivalent circuits Magnetic separation

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Automated Colorectal Polyps Detection from Endoscopic Images using MultiResUNet Framework with Attention Guided Segmentation

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Human-Centric Intelligent systems 2024年第2期4卷 299-315页

作者： Ahamed, Md. Faysal Islam, Md. Rabiul Nahiduzzaman, Md. Chowdhury, Muhammad E. H. Alqahtani, Abdulrahman Murugappan, M. Department of Computer Science & Engineering Rajshahi University of Engineering & Technology Rajshahi Bangladesh Department of Electrical & Computer Engineering Rajshahi University of Engineering & Technology Rajshahi Bangladesh Department of Electrical Engineering Qatar University Doha Qatar Department of Biomedical Technology College of Applied Medical Sciences Al-Kharj Prince Sattam Bin Abdulaziz University Al-Kharj Saudi Arabia Department of Medical Equipment Technology College of Applied Medical Science Majmaah University Majmaah City Saudi Arabia Intelligent Signal Processing (ISP) Research Lab Department of Electronics and Communication Engineering Kuwait College of Science and Technology Doha Kuwait Department of Electronics and Communication Engineering Vels Institute of Sciences Technology and Advanced Studies Chennai India DCenter for Unmanned Autonomous Systems (CoEUAS) Universiti Malaysia Perlis Perlis Malaysia

The early detection of colorectal polyps is crucial for the reduction of mortality rates. However, manually identifying polyps is time-consuming and expensive, increasing the risk of missing them. Our paper aims to address this issue by presenting an automated segmentation approach for colorectal polyps. This paper proposes a method that combines a skip connection with hybrid attention guidance (AG) using attention guidance (AG) and residual path frameworks to identify salient features. Furthermore, we augment test samples using original, horizontal flip, and vertical flip transformations to enhance model robustness through Test Time Augmentation (TTA). The model was trained with Kvasir-seg samples and evaluated on Kvasir-seg and CVC-ClinicDB datasets to gauge generalizability. A significant accuracy (0.9546), a Dice Similarity Coefficient (DSC) of 0.8557, a Cross-section over Union (IoU) of 0.8824, a Recall (0.8221), a Precision (0.8922), an area under Receiver Operating Characteristics (ROC-AUC) of 0.9454, and an area under Precision-Recall (AUC-PR) of 0.8717 were achieved without TTA. Through TTA integration, accuracy (0.9993), DSC (0.8663), IoU (0.8277), Recall (0.8060), Precision (0.9364), and ROC-AUC (0.9587) have been improved. A comparison of our framework with state-of-the-art models demonstrated its effectiveness and segmentation capabilities. Additionally, the proposed model contains only 0.47 million parameters and a weight size of 6.71 MB, illustrating its potential for clinical diagnostics. A computer-aided diagnosis (CAD) system improves patient outcomes by detecting colorectal polyps early and improving segmentation accuracy.

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Passivity of nonlinear time-delay systems

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IFAC-PapersOnLine 2023年第2期56卷 8568-8573页

作者： Yu Kawano Saeed Ahmed Michele Cucuzzella Jacquelien M.A. Scherpen Graduate School of Advanced Science and Engineering Hiroshima University Higashi-hiroshima 739-8527 Japan Jan C. Willems Center for Systems and Control ENTEG Faculty of Science and Engineering University of Groningen 9747 AG Groningen The Netherlands Department of Electrical Computer and Biomedical Engineering University of Pavia 27100 Pavia Italy

This paper presents passivity-based control of nonlinear systems with retarded delays in the state. To this end, we first show that the standard passivity concept can naturally be generalized to time-delay systems, which readily implies that a feedback interconnection (with or without communication delays) of passive time-delay systems is also passive. Then, we propose a storage functional for passivity analysis and further use it for stability analysis of controlled-passive time-delay systems. In particular, invoking an invariance principle for retarded functional differential equations, we show that a passive time-delay system can always be stabilized by a static output feedback controller under a delayed version of the zero-state detectability assumption.

关键词： Passivity nonlinear systems time-delay systems retarded functional differential equations stabilizing control

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Ion irradiation induced crystalline disorder accelerates interfacial phonon conversion and reduces thermal boundary resistance

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Physical Review B 2024年第16期109卷 165421-165421页

作者： Thomas W. Pfeifer Henry Aller Eric R. Hoglund Ethan A. Scott John A. Tomko Habib Ahmad Alan Doolittle Ashutosh Giri Khalid Hattar Alan J. H. McGaughey Patrick E. Hopkins Department of Mechanical and Aerospace Engineering University of Virginia Charlottesville Virginia 22904 USA Department of Mechanical Engineering Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA Department of Materials Science and Engineering University of Virginia Charlottesville Virginia 22904 USA Sandia National Laboratories Albuquerque New Mexico 87185 USA School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta Georgia 30332 USA Center for Advanced Electronics & Photovoltaic Engineering IIUI Islamabad Department of Mechanical Industrial and Systems Engineering University of Rhode Island Kingston Rhode Island 02881 USA Department of Nuclear Engineering University of Tennessee Knoxville Tennessee 37996 USA Department of Physics University of Virginia Charlottesville Virginia 22904 USA

Traditional understanding of the thermal boundary resistance (TBR) across solid-solid interfaces posits that the vibrational densities of states overlap between materials dictates interfacial energy transport, with phonon scattering occurring at the interface. Using atomistic simulations, we show a mechanism for control of TBR; point defects near an interface can lead to both short- and midrange disorder, accelerating the conversion of vibrational energy between bulk and interfacial modes, ultimately reducing the TBR. We experimentally demonstrate this reduction through ion irradiation of gallium nitride and subsequently measuring the TBR across Al/GaN interfaces.

关键词： Crystal defects Defects Irradiation effects Lattice dynamics Phonons Thermal boundary conductance Vibrational states Interfaces Semiconductor compounds Transducers Ion implantation Molecular dynamics Thermoreflectance

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Stochastic model of noise for a quantum thermal transistor

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Physical Review B 2023年第23期108卷 235421-235421页

作者： Uthpala N. Ekanayake Sarath D. Gunapala Malin Premaratne Advanced Computing and Simulation Laboratory (AχL) Department of Electrical and Computer Systems Engineering Monash University Clayton Victoria 3800 Australia Jet Propulsion Laboratory California Institute of Technology Pasadena California 91109 USA

Our focus in this investigation lies in developing a noise model for a quantum thermal transistor model inspired by its electronic counterpart, with the primary aim of establishing a platform for constructing analogous models. Previous studies on coupled two-level systems-based thermal transistors were focused on their average energy exchange. In this paper, we shift our attention to exploring the stochastic behavior of such thermal transistors due to the disturbances caused to their environment, such as continuous measurements. In the literature, the master equation for the transistor model is derived using the reduced dynamics method. This way, it masks the study of the stochastic nature of the energy flows in the system due to disturbances to the environment. In this paper, we describe a quantum trajectory under measurement theory whose ensemble average unravels the master equation for a quantum thermal transistor. This allows us to analyze the fluctuations and noise levels in the transistor model with greater detail. Then, we produce a numerical solution for the transistor dynamics based on Euler-Maruyama approximation. This helps to establish a model for the thermal transistor, drawing parallels to the small-signal/noise model in an electronic transistor. We define two parameters, thermal conductance and output thermal resistance, to describe the small signal-like model for the thermal transistor. Through these investigations, we seek to gain insights that can help design advanced heat management devices at the quantum level.

关键词： Open quantum systems Quantum gates Thermal properties Nanotechnology Transistors

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CHIMERA: A Hybrid Estimation Approach to Limit the Effects of False Data Injection Attacks

CHIMERA: A Hybrid Estimation Approach to Limit the Effects o...

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2021 IEEE International Conference on Communications, Control, and Computing Technologies for Smart Grids, SmartGridComm 2021

作者： Liu, Xiaorui Hu, Yaodan Konstantinou, Charalambos Jin, Yier FAMU-FSU College of Engineering Center for Advanced Power Systems Florida State University United States University of Florida Department of Electrical and Computer Engineering United States CEMSE Division Saudi Arabia

ISBN: (纸本)9781665415026

The reliable operation of power grid is supported by energy management systems (EMS) that provide monitoring and control functionalities. Contingency analysis is a critical application of EMS to evaluate the impacts of outages and prepare for system failures. However, false data injection attacks (FDIAs) have demonstrated the possibility of compromising sensor measurements and falsifying the estimated power system states. As a result, FDIAs may mislead system operations and other EMS applications including contingency analysis and optimal power flow. In this paper, we assess the effect of FDIAs and demonstrate that such attacks can affect the resulted number of contingencies. In order to mitigate the FDIA impact, we propose CHIMERA, a hybrid attack-resilient state estimation approach that integrates model-based and data-driven methods. CHIMERA combines the physical grid information with a Long Short Term Memory (LSTM)-based deep learning model by considering a static loss of weighted least square errors and a dynamic loss of the difference between the temporal variations of the actual and the estimated active power. Our simulation experiments based on the load data from New York state demonstrate that CHIMERA can effectively mitigate 91.74% of the cases in which FDIAs can maliciously modify the contingencies. © 2021 IEEE.

关键词： Energy management systems

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