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arXiv 2021年

作者： Fang, Wenzhi Jiang, Yuning Shi, Yuanming Zhou, Yong Chen, Wei Letaief, Khaled B. The School of Information Science and Technology ShanghaiTech University Shanghai201210 China Automatic Control Laboratory EPFL Switzerland The Department of Electronic Engineering Tsinghua University Beijing100084 China The Department of Electronic and Computer Engineering Hong Kong University of Science and Technology Hong Kong

Over-the-air computation (AirComp) is a disruptive technique for fast wireless data aggregation in Internet of Things (IoT) networks via exploiting the waveform superposition property of multiple-access channels. However, the performance of AirComp is bottlenecked by the worst channel condition among all links between the IoT devices and the access point. In this paper, a reconfigurable intelligent surface (RIS) assisted AirComp system is proposed to boost the received signal power and thus mitigate the performance bottleneck by reconfiguring the propagation channels. With an objective to minimize the AirComp distortion, we propose a joint design of AirComp transceivers and RIS phase-shifts, which however turns out to be a highly intractable non-convex programming problem. To this end, we develop a novel alternating minimization framework in conjunction with the successive convex approximation technique, which is proved to converge monotonically. To reduce the computational complexity, we transform the subproblem in each alternation as a smooth convex-concave saddle point problem, which is then tackled by proposing a Mirror-Prox method that only involves a sequence of closed-form updates. Simulations show that the computation time of the proposed algorithm can be two orders of magnitude smaller than that of the state-of-the-art algorithms, while achieving a similar distortion performance. Copyright © 2021, The Authors. All rights reserved.

关键词： Mirrors

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Decentralized control barrier functions for coupled multi-agent systems under signal temporal logic tasks

arXiv

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arXiv 2020年

作者： Lindemann, Lars Dimarogonas, Dimos V. Department of Automatic Control School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm100 44 Sweden

We study the problem of controlling multi-agent systems under a set of signal temporal logic tasks. Signal temporal logic is a formalism that is used to express time and space constraints for dynamical systems. Recent methods to solve the control synthesis problem for single-agent systems under signal temporal logic tasks are, however, subject to a high computational complexity. Methods for multi-agent systems scale at least linearly with the number of agents and induce even higher computational burdens. We propose a computationally-efficient control strategy to solve the multi-agent control synthesis problem that results in a robust satisfaction of a set of signal temporal logic tasks. In particular, a decentralized feedback control law is proposed that is based on time-varying control barrier functions. The obtained control law is discontinuous and formal guarantees are provided by nonsmooth analysis. Simulations show the efficacy of the presented method. Copyright © 2020, The Authors. All rights reserved.

关键词： Multi agent systems

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Experimental study reliability and functional stability of the social graph

Experimental study reliability and functional stability of t...

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International Scientific Conference on Informatics 2018: Problems, Methodologies and Technologies, IPMT 2018

作者： Algazinov, E.K. Garshina, V.V. Stepantsov, V.A. Desyatirikova, E.N. Computer Science Department Voronezh State University Voronezh Russia Department Automatic Control Systems Department Voronezh State Technical University Voronezh Russia

The article is devoted to the results of an experimental study the integrity, reliability and efficiency of the social network graph as a complex network in terms of transferring messages between users. The computed network parameters that affect the evaluation of the efficiency of its functioning are determined;the integral coefficient of network stability loss is developed;formulated heuristic rules for assessing the functional stability of a social network based on the parameters of the social graph are formulated. © Published under licence by IOP Publishing Ltd.

关键词： Complex networks

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Parameter estimation and control of an unmanned aircraft-based transportation system for variable-mass payloads

Parameter estimation and control of an unmanned aircraft-bas...

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作者： Alatorre, Armando Espinoza, Eduardo S. Sánchez, Bonifacio Ordaz, Patricio Muñoz, Filiberto García Carrillo, Luis Rodolfo French-Mexican Laboratory of Informatics and Automatics Center of Research and Advanced Studies of the National Polytechnic Institute México City Mexico Automatic Control Department Center of Research and Advanced Studies of the National Polytechnic Institute México City Mexico Research Center of Information Technologies and Systems Autonomous University of the State of Hidalgo Hidalgo Mexico Klipsch School of Electrical and Computer Engineering New Mexico State University Las CrucesNM United States

This paper deals with the development of an adaptive robust controller for an Unmanned Aircraft System with variable mass. The goal is to improve trajectory tracking and energy performance while the aircraft mass is gradually reducing due to payload release. To improve the trajectory tracking performance, we propose an algorithm that merges the concepts of least squares method and sliding mode observer for the estimation of the vehicle mass. The nonlinear observer estimates the linear velocities and accelerations, which are further used to obtain the vehicle mass. A robust adaptive pole placement controller based on the Attractive Ellipsoid Method uses this estimation to update the controllers gains due to the mass variation. To validate the effectiveness of the proposed algorithm for performing aerial transportation and deployment of payloads, we present a numerical example comparing the performance of the proposed method with respect to using Proportional Derivative controllers as well as Robust controllers. © 2021 Chinese automatic control Society and John Wiley & Sons Australia, Ltd

关键词： controllers

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A sliding mode controller design for thermal comfort in buildings

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Engineering Transactions 2019年第4期67卷 475-489页

作者： Skruch, Pawel Dlugosz, Marek AGH University of Science and Technology Faculty of Electrical Engineering Automatics Computer Science and Biomedical Engineering Department of Automatic Control and Robotics Al. Mickiewicza 30 Kraków30-059 Poland

One of the factors determining comfort in buildings is the indoor air temperature of the rooms. A control system, part of the home automation system, should stabilise air temperature to the desired level, despite various disturbances such as the presence of random or occasional sources of heat. Inaccurate models of the dynamics of air temperature changes in buildings prescribe the use of robust control methods, a type of which is the sliding mode controller. This article presents the application of a sliding mode controller (SMC) to home automation systems, designed to control air temperature inside a building. The sliding-mode controller makes use of sliding surfaces, which are defined by the assumed trajectory and the system output. The control law is designed in such a way that the trajectory of the system tends to the sliding surface from any initial point and remains on it after reaching the sliding surface. In this article, a model at air temperature change dynamics inside a building is presented. The modelling approach relies on the lumped-parameter methodology, in which distributed physical properties are represented by lumped parameters (such as thermal capacity or resistance). The model takes into account the loss of heat through conduction and ventilation, as well as internal heat gain. The parameters of the model can be obtained easily from the thermal properties of the construction materials. Theoretical considerations were applied in simulation experiments and the results of these experiments confirm the performance improvement achieved by the proposed solutions. © 2019, Polish Academy of Sciences. All rights reserved.

关键词： Atmospheric temperature

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Power Quality Management of Interconnected Microgrids using Model Predictive control ⁎

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IFAC-PapersOnLine 2020年第2期53卷 12918-12923页

作者： F. Garcia-Torres S. Vazquez C. Bordons I. Moreno-Garcia A. Gil P. Roncero-Sanchez Centro Nacional del Hidrogeno Puertollano (Ciudad Real) Spain Electronic Engineering Department Universidad de Sevilla Sevilla Spain Systems Engineering and Automatic Control Department Universidad de Sevilla Sevilla Spain Department of Electronic and Computer Engineering Universidad de Cordoba Cordoba Spain Systems Engineering and Automatic Control Department University of Castilla-La Mancha Ciudad Real Spain

In this paper, the power quality of interconnected microgrids is managed using a Model Predictive control (MPC) methodology which manipulates the power converters of the microgrids in order to achieve the requirements. The control algorithm is developed for the microgrids working modes: grid-connected, islanded and interconnected. The results and simulations are also applied to the transition between the different working modes. In order to show the potential of the control algorithm a comparison study is carried out with classical Proportional-Integral Pulse Width Modulation (PI-PWM) based controllers. The proposed control algorithm not only improves the transient response in comparison with classical methods but also shows an optimal behavior in all the working modes, minimizing the harmonics content in current and voltage even with the presence of non-balanced and non-harmonic-free three-phase voltage and current systems.

关键词： Interconnected systems Harmonics Predictive control Power System control

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The role of input imaging combination and ADC threshold on segmentation of acute ischemic stroke lesion using U-Net

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European Radiology 2023年第9期33卷 6157-6167页

作者： Li, Ya-Hui Lin, Shao-Chieh Chung, Hsiao-Wen Chang, Chia-Ching Peng, Hsu-Hsia Huang, Teng-Yi Shen, Wu-Chung Tsai, Chon-Haw Lo, Yu-Chien Lee, Tung-Yang Juan, Cheng-Hsuan Juan, Cheng-En Chang, Hing-Chiu Liu, Yi-Jui Juan, Chun-Jung Graduate Institute of Biomedical Electronics and Bioinformatics National Taiwan University Taipei Taiwan Department of Medical Imaging China Medical University Hsinchu Hospital No. 199 Sec. 1 Xinglong Rd. Zhubei City Hsinchu County 302 Hsinchu Taiwan Ph.D. Program in Electrical and Communication Engineering Feng Chia University Taichung Taiwan Department of Electrical Engineering National Taiwan University Taipei Taiwan Department of Management Science National Yang Ming Chiao Tung University Hsinchu Taiwan Department of Biomedical Engineering and Environmental Sciences National Tsing Hua University Hsinchu Taiwan Department of Electrical Engineering National Taiwan University of Science and Technology Taipei Taiwan Department of Radiology School of Medicine College of Medicine China Medical University Taichung Taiwan Department of Medical Imaging Medical University Hospital Taichung Taiwan Department of Neurology China Medical University Hospital Taichung Taiwan Cheng Ching Hospital Taichung Taiwan Master’s Program of Biomedical Informatics and Biomedical Engineering Feng Chia University Taichung Taiwan Department of Automatic Control Engineering Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung 40724 Taiwan Department of Biomedical Engineering The Chinese University of Hong Kong ERB1112 11/F William M.W. Mong Engineering Building N.T Shatin Hong Kong Multi-Scale Medical Robotics Center The Chinese University of Hong Kong N.T Shatin Hong Kong Department of Biomedical Engineering National Defense Medical Center Taipei Taiwan Department of Computer Science and Information Engineering National Taiwan University Taipei Taiwan

Background: To evaluate the effect of the weighting of input imaging combo and ADC threshold on the performance of the U-Net and to find an optimized input imaging combo and ADC threshold in segmenting acute ischemic stroke (AIS) lesion. Methods: This study retrospectively enrolled a total of 212 patients having AIS. Four combos, including ADC-ADC-ADC (AAA), DWI-ADC-ADC (DAA), DWI-DWI-ADC (DDA), and DWI-DWI-DWI (DDD), were used as input images, respectively. Three ADC thresholds including 0.6, 0.8 and 1.8 × 10^–3 mm²/s were applied. Dice similarity coefficient (DSC) was used to evaluate the segmentation performance of U-Nets. Nonparametric Kruskal–Wallis test with Tukey–Kramer post-hoc tests were used for comparison. A p <.05 was considered statistically significant. Results: The DSC significantly varied among different combos of images and different ADC thresholds. Hybrid U-Nets outperformed uniform U-Nets at ADC thresholds of 0.6 × 10^–3 mm²/s and 0.8 × 10^–3 mm²/s (p <.001). The U-Net with imaging combo of DDD had segmentation performance similar to hybrid U-Nets at an ADC threshold of 1.8 × 10^–3 mm²/s (p =.062 to 1). The U-Net using the imaging combo of DAA at the ADC threshold of 0.6 × 10^–3 mm²/s achieved the highest DSC in the segmentation of AIS lesion. Conclusions: The segmentation performance of U-Net for AIS varies among the input imaging combos and ADC thresholds. The U-Net is optimized by choosing the imaging combo of DAA at an ADC threshold of 0.6 × 10^–3 mm²/s in segmentating AIS lesion with highest DSC. Key Points: • Segmentation performance of U-Net for AIS differs among input imaging combos. • Segmentation performance of U-Net for AIS differs among ADC thresholds. • U-Net is optimized using DAA with ADC = 0.6 × 10^–3mm²/s. © 2023, The Author(s), under exclusive licence to European Society of Radiology.

关键词： Deep Learning Diffusion Magnetic Resonance Imaging Ischemic Stroke Neural Networks, computer Retrospective Study

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2D nanomaterials for realization of flexible and wearable gas sensors: A review

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Chemosphere 2024年 352卷 141234页

作者： Pawar, Krishna Kiran Kumar, Ashok Mirzaei, Ali Kumar, Mahesh Kim, Hyoun Woo Kim, Sang Sub Division of Materials Science and Engineering Hanyang University Seoul 04763 South Korea The Research Institute of Industrial Science Hanyang University Seoul 04763 South Korea School of Nanoscience and Technology Shivaji University Kolhapur 416004 India Department of Electrical Engineering Indian Institute of Technology Jodhpur 342030 India Department of Materials Science and Engineering Shiraz University of Technology Shiraz 715557-13876 Iran Department of Cybernetics Nanotechnology and Data Processing Faculty of Automatic Control Electronics and Computer Science Silesian University of Technology Akademicka 16 Gliwice 44-100 Poland Department of Materials Science and Engineering Inha University Incheon 22212 South Korea

Gas sensors are extensively employed for monitoring and detection of hazardous gases and vapors. Many of them are produced on rigid substrates, but flexible and wearable gas sensors are needed for intriguing usage including the internet of things (IoT) and medical devices. The materials with the greatest potential for the fabrication of flexible and wearable gas sensing devices are two-dimensional (2D) semiconducting nanomaterials, which consist of graphene and its substitutes, transition metal dichalcogenides, and MXenes. These types of materials have good mechanical flexibility, high charge carrier mobility, a large area of surface, an abundance of defects and dangling bonds, and, in certain instances adequate transparency and ease of synthesis. In this review, we have addressed the different 2D nonmaterial properties for gas sensing in the context of fabrication of flexible/wearable gas sensors. We have discussed the sensing performance of flexible/wearable gas sensors in various forms such as pristine, composite and noble metal decorated. We believe that content of this review paper is greatly useful for the researchers working in the research area of fabrication of flexible/wearable gas sensors. © 2024 Elsevier Ltd

关键词： 2D nanomaterials Flexible/wearable gas sensor Graphene MXenes Sensing mechanism TMDs Toxic gas

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Activation maps of convolutional neural networks as a tool for brain degeneration tracking in early diagnosis of dementia in Parkinson's disease based on magnetic resonance imaging

Research Square

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Research Square 2021年

作者： Suwalska, Aleksandra Siuda, Joanna Kocot, Szymon Zmuda, Weronika Rudzinska-Bar, Monika Polanska, Joanna Department of Data Science and Engineering Faculty of Automatic Control Electronics and Computer Science Silesian University of Technology Gliwice Poland Department of Neurology School of Medicine Medical University of Silesia Katowice Poland Department of Neurology Faculty of Medicine and Health Sciences Andrzej Frycz Modrzewski Krakow University Krakow Poland

Identification of Parkinson’s Disease (PD) patients at risk for development of dementia is crucial for early intervention. However, diagnosing dementia in PD patients requires advanced, time-consuming and expensive imaging techniques (such as DaT-SCAN-SPECT). The study aims to prove the usefulness of convolutional neural networks (CNN) for the identification of brain areas related to the progress of cognitive impairment by using standard Magnetic Resonance Imaging (MRI) sequences. T1&T2 sequences of 18 patients were used in the pilot study. Activation maps were generated, and the brain regions most involved in the classification process were identified, showing areas potentially significant in the diagnosis of cognitive impairment severity. The cerebellum was proven significant for distinguishing the above-mentioned classes in relative cerebellum volume (ANOVA p-value=0.0038 with large effect size η2=0.5254) and folding (p-value=0.0031, η2=0.5357), which is consistent with reports by other authors. Our analysis demonstrates that convolutional neural networks combined with a proper image preprocessing pipeline could be used for feature extraction in MRI sequences and can successfully support the identification of disease-specific abnormalities of the brain image. © 2021, CC BY.

关键词： Magnetic resonance imaging

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Human Internal Organs Diagnostics based on Heart Biophysical Signals

Human Internal Organs Diagnostics based on Heart Biophysical...

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28th Saint Petersburg International Conference on Integrated Navigation Systems, ICINS 2021

作者： Achi'Ldiev, Vladimir M. Evseeva, Yuliya N. Gruzevich, Yuriy K. Bedro, Nikolay A. Basarab, Mikhail A. Uspenskiy, Vyacheslav M. Konnova, Natalya S. Scientific Production Unity 'Geofizika-nv' Stock Company Microelectromechanical Systems Department Moscow Russia Mytishchi Branch of the Bauman MSTU Department of Automatic Control Systems Moscow Russia Scientific Production Unity 'Geofizika-nv' Stock Company Bauman Moscow State Technical University Moscow Russia Department of High-Performance Computer Technology Bauman Moscow State Technical University Moscow Russia Department of Emergency Medicine Branch of the Military Medical Academy Named after S. M. Kirov Moscow Russia

ISBN: (纸本)9785919950806

The report is devoted to research aimed at studying and implementing a method of human internal organs diseases diagnosing that is based on biophysical signals of the heart. The research includes the development of a remote diagnostics system, an application of information analysis methods to various registered signals of cardiac activity, as well as a development of a system based on deep learning. The paper introduces a set of metrics for evaluating the results obtained, an original numerical experiment that has been set up using original developed mathematical software complex and results of the evaluation of several models for solving the problem of automated diagnostics of diseases. © 2021 Concern CSRI Elektropribor, JSC.

关键词： Wavelet analysis

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