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SSRN 2023年

作者： Li, Xueyi Yu, Tianyu Wang, Xiangkai Li, Daiyou Xie, Zhijie Kong, Xiangwei College of Mechanical and Electrical Engineering Northeast Forestry University Harbin150040 China Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern University Shenyang110819 China School of Mechanical Engineering and Automation Northeastern University Shenyang110819 China

Unsupervised rotation mechanical fault diagnosis methods have become popular, but existing unsupervised methods still have some issues. For example, it is challenging to capture vibration signal features at different scales and to address partial class confusion. To improve the diagnostic performance, this study introduces a multi-scale, Efficient Channel Attention (ECA) attention mechanism, Joint Adaptation Network (JAN), and Minimum Class Confusion (MCC) for addressing the aforementioned issues. Firstly, the authors design a multi-scale fault feature extraction module to capture discriminative information at different scales in vibration signals. Secondly, the authors introduce the ECA attention mechanism to weight the extracted features at the channel level, enhancing useful features and suppressing redundant features. Then, the authors employ the JAN method to establish local maximum mean discrepancy, enabling adaptation between corresponding sub-domains of the source and target domains, avoiding the problem of being too close. Finally, the authors use MCC as the loss function to reduce prediction confusion between correct and ambiguous categories in target samples, thus improving transfer performance. Experimental results demonstrate that the proposed method exhibits excellent performance in unsupervised rotation mechanical fault diagnosis tasks. © 2023, The Authors. All rights reserved.

关键词： Fault detection

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Vibrations Characteristics Analysis of Metal Composite 17-4ph Material Extrusion Additively Manufactured Parts Under Amplitude Dependence Property

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SSRN 2023年

作者： Siyajeu, Yannick Xu, Zhuo Jiang, Shijie Li, Hui Wen, Bangchun Li, He School of Mechanical Engineering and Automation Northeastern University Shenyang110819 China Key laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Northeastern University Shenyang110819 China School of Mechanical Engineering Northeast Electric Power University Jilin132014 China

In this study, a dynamic linear model of a metal composite filament ultra-fuse 17-4 PH stainless-steel material extrusion (ME) parts has been established considering the amplitude dependence. Material extrusion plates have been built in x and z-direction. Based on the Jones-Nelson model an investigation of the natural frequency and response and damping ratio of ultra-fuse 17-4PH metal composite material extrusion specimens has been completed. Equations of the proposed dynamic model have been solved by the combination of the orthogonal polynomial method and energy method. The Newton-Raphson iteration has been employed to predict the natural frequencies and responses of the ultra-fuse 17-4 PH stainless-steel material extrusion manufactured parts. The results indicate that the predicted damping characteristics of the ultra-fuse 17-4 PH metal composite material extrusion parts have a good consistency with the experimental ones, meanwhile, when amplitude vibration increases from [0.25g…2.00g], the response of the ultra-fuse 17-4 PH metal composite material extrusion parts increase as well both for x and z-direction samples. © 2023, The Authors. All rights reserved.

关键词： Iterative methods

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Additive manufacturing of silicon carbide microwave-absorbing metamaterials

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Additive Manufacturing Frontiers 2025年第1期4卷

作者： Zhao, Hanqing Liao, Qingwei Li, Yinghao Chu, Xiangcheng Yuan, Songmei Qin, Lei Key Laboratory of Sensors Beijing Information Science and Technology University Beijing 100192 China Key Laboratory of Modern Measurement & Control Technology Ministry of Education Beijing Information Science & Technology University Beijing 100192 China State Key Laboratory of New Ceramics and Fine Processing School of Material Science and Engineering Tsinghua University Beijing 100084 China School of Mechanical Engineering and Automation Beihang University Beijing 100191 China

SiC is a wave-absorbing material with good dielectric properties, high-temperature resistance, and corrosion resistance, which has great potential for development in the field of high-temperature wave-absorbing. However, SiC is limited by its low impedance-matching performance and single wave-absorbing mechanism. Therefore, compatible metamaterial technologies are required to enhance its wave-absorbing performance further. The electromagnetic wave (EMW) absorbing metamaterials can realize perfect absorption of EMWs in specific frequency bands and precise regulation of EMW phase, propagation mode, and absorption frequency bands through structural changes. However, the traditional molding methods for manufacturing complex geometric shapes require expensive molds, involve process complexity, and have poor molding accuracy and other limitations. Therefore, additive manufacturing (AM) technology, through material layered stacking to achieve the processing of materials, is a comprehensive multidisciplinary advanced manufacturing technology and has become the core technology for manufacturing metamaterials. This review introduces the principles and applications of different AM technologies for SiC and related materials, discusses the current status and development trends of various AM technologies for fabricating silicon–carbon-based wave-absorbing metamaterials, summarizes the limitations and technological shortcomings of existing AM technologies for fabricating silicon–carbon-based wave-absorbing metamaterials, and provides an outlook for the future development of related AM technologies. © 2024 The Author(s)

关键词： Additive manufacturing Electromagnetic absorption Metamaterials SiC

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Fragility-Aware Stealthy Attack Strategy for Multi-Robot systems against Multi-Hop Wireless Networks

Fragility-Aware Stealthy Attack Strategy for Multi-Robot Sys...

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IEEE Conference on Decision and control

作者： Yun Gao Kai Luo Chongrong Fang Jianping He Dept. of Automation Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China and Shanghai Engineering Research Center of Intelligent Control and Management Shanghai China

ISBN: (数字)9781665467612

ISBN: (纸本)9781665467629

This paper proposes a fragility-aware stealthy attack for multiple mobile robots to secretly learn the accurate model of a multi-hop wireless network (MHWN). The stealthy attack scenario consists of three steps: active detection, node hijacking, and network eavesdropping. Our goal is to design distributed motion control strategies for naive attackers, for obtaining the connectivity information to evaluate the fragility degree of each node in MHWN. We designed a switching control strategy, which includes (i) move-to-fragile-neighbors-barycenter (MFNB) law and (ii) move-to-undetected-region-centroid (MURC) law. This strategy can drive mobile attackers to detect, hijack and eavesdrop on the MHWN’s nodes as quickly as possible. As a result, the fragility degree map of MHWN can be secretly learned to paralyze the whole network. Finally, the simulation results show that the proposed strategy is effective.

关键词： Wireless networks Simulation Spread spectrum communication Switches control systems Stability analysis Multi-robot systems

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Design of echo state network with multi-objective optimization algorithm and l1 regularization

Design of echo state network with multi-objective optimizati...

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第34届中国控制与决策会议

作者： Zhanhong Wu Cuili Yang Beijing University of Technology Faculty of Information TechnologyBeijing Key Laboratory of Computational Intelligence and Intelligent SystemEngineering Research Center of Intelligent Perception and Autonomous Control Ministry of Education

In this paper,a new approach for optimizing the structure and prediction error of echo state network（ESN） is *** is a kind of recurrent neural network with simple training and strong generalization *** is an important structure of ESN,which determine network ***,multi-objective optimization algorithm is used to optimize network structure and training error ***,a local search algorithm based on l regularization is used to accelerate *** experiment results of time series prediction and standard classification show that MESN can improve the network prediction performance while sparse network structure.

关键词： Echo state network multi-objective optimization algorithm l1 regularization

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Sliding Mode Observation and control for Overhead Cranes with Varying Rope Length

Sliding Mode Observation and Control for Overhead Cranes wit...

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2021 China Automation Congress, CAC 2021

作者： Huan, Xuwei Niu, Dan Li, Qi Yang, Jun Liu, Guoyao Chen, Xisong Xiao, Xi Key Laboratory of Measurement and Control of CSE Ministry of Education Southeast University Nanjing China Department of Aeronautical and Automotive Engineering Loughborough University LoughboroughLE11 3TU United Kingdom Nanjing Sciyon Automation Group Co. Ltd Nanjing China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing China

ISBN: (纸本)9781665426473

This paper proposes a state observer and controller based on the second-order sliding mode scheme for underactuated overhead cranes with load hoisting and lowering. The designed state observer can effectively estimate the uncertainly and unmodeled dynamics of crane systems, and provide appropriate driving force compensations for the sliding mode controller designed by coupling the load swing angle. This guarantees an accurate load positioning and residual swing elimination. Based on the Lyapunov stability criterion, the asymptotic stability of the control system is proved Several simulations are implemented to verify the effectiveness and robustness of the proposed controller for anti-sway and positioning controls. © 2021 IEEE

关键词： Asymptotic stability

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3d Surface Detection and Segmentation from Point Clouds Via Quadric Fits Based on Dbscan Clustering

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SSRN 2024年

作者： Xie, Tingting Chen, Hui Liu, Wanquan Zhou, Rongyu Li, Qilin College of Automation Engineering Shanghai University of Electric Power Shanghai200090 China Key Laboratory of System Control and Information Processing Ministry of Education Shanghai200240 China School of Intelligent Systems Engineering Sun Yat-sen University Guangzhou510275 China School of Electrical Engineering Computing and Mathematical Sciences Curtin University BentleyWA Australia

Extracting surfaces from 3D point clouds is significant in reconstructing and transforming these discrete points into their corresponding models. Scannedpoint clouds are often accompanied by noise, and the existing methods mainly rely on local feature similarities for surface extractions. Errors in estimatingthe feature information may lead to incorrect surface detection. In this paper we propose a surface extraction and boundary detection method based onclustering technique. The method can be described in three steps: In the first step, a normal correction is carried out using the information from theneighbourhood of points with sharp features. The second step is to cluster the points that meet the coplanar condition of the local quadric surface (LQS).In the third step, surface merger is performed by merging the local surfaces satisfying the merging conditions. Experimental validation is carried outto determine the effectiveness of the proposed method. The experimental results show improved surface extraction accuracy of the proposed methodin comparison to RANSAC, RG, LCCP, C2NO and HT methods. © 2024, The Authors. All rights reserved.

关键词： Merging

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Estimating the value of a statistical life in China: A contingent valuation study in six representative cities

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Chinese Journal of Population,Resources and Environment 2023年第4期21卷 269-278页

作者： Chaoji Cao Xinke Song Wenjia Cai Yichao Li Jianhui Cong Xueying Yu Mengzhao Gao Can Wang Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua UniversityBeijing100084China Center for Healthy Cities Institute for China Sustainable UrbanizationTsinghua UniversityBeijing100084China Tsinghua Urban Institute Tsinghua UniversityBeijing100084China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Center for Statistical Science Tsinghua UniversityBeijing100084China Department of Industrial Engineering Tsinghua UniversityBeijing100084China School of Economics and Management Shanxi UniversityTaiyuan030000China School of Economics and Management Beihang UniversityBeijing100191China Beijing Advanced Innovation Center for Big Data-based Precision Medicine Beihang UniversityBeijing100191China Key Laboratory of Big Data-Based Precision Medicine(Beihang University) Ministry of Industry and Information TechnologyBeijing100191China

The value of a statistical life(VSL)is a crucial tool for monetizing health *** explore the VSL in China,this study examines people’s willingness to pay(WTP)to reduce death risk from air pollution in six representative cities in China based on face-to-face contingent valuation interviews(n=3936)from March 7,2019 to September 30,*** results reveal that the WTP varied from CNY 455 to 763 in 2019(USD 66-111),corresponding to a VSL range of CNY 3.79-6.36 million(USD 549395-921940).The VSL in China in 2019 is estimated to be CNY 4.76 million(USD 689659).The statistics indicate that monthly expenditure levels,environmental concerns,risk attitudes,and assumed market acceptance,which have seldom been dis‐cussed in previous studies,significantly impact WTP and *** findings will serve as a reference for ana‐lyzing mortality risk reduction benefits in future research and for policymaking.

关键词： Air pollution Contingent valuation method Willingness to pay Value of a statistical life China

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Simultaneous Strain and Temperature measurement Based on Chaotic Brillouin Optical Correlation-Domain Analysis in Large-Effective-Area Fibers

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Photonic Sensors 2021年第4期11卷 377-386页

作者： Xiaocheng ZHANG Shuangshuang LIU Jianzhong ZHANG Lijun QIAO Tao WANG Shaohua GAO Mingjiang ZHANG Key Laboratory of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan University of TechnologyTaiyuan 030024China College of Physics and Optoelectronics Institute of Optoelectronic EngineeringTaiyuan University of TechnologyTaiyuan 030024China

Chaotic Brillouin optical correlation domain analysis(BOCDA)has been proposed and experimentally demonstrated with the advantage of high spatial ***,it faces the same issue of the temperature and strain *** this paper,the simultaneous measurement of temperature and strain can be preliminarily achieved by analyzing the two Brillouin frequencies of the chaotic laser in a large-effective-area fiber(LEAF).A temperature resolution of 1℃ and a strain resolution of 20μξ can be obtained with a spatial resolution of *** actual temperature and strain measurement errors are 0.37℃ and 10μξ,respectively,which are within the maximum measurement errors.

关键词： Brillouin scattering simultaneous strain and temperature measurement chaotic laser BOCDA LEAF

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Two-step Optimal Allocation of Stationary and Mobile Energy Storage systems in Resilient Distribution Networks

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Journal of Modern Power systems and Clean Energy 2021年第4期9卷 788-799页

作者： Xinyi Jiang Jian Chen Qiuwei Wu Wen Zhang Yicheng Zhang Jie Liu Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250061China Center for Electric Power and Energy(CEE) Department of Electrical EngineeringTechnical University of Denmark(DTU)2800 Kongens LyngbyDenmark Institute for Infocomm Research(I2R) Agency for ScienceTechnology and Research(A*STAR)Singapore State Grid Yantai Power Supply Company YantaiChina

Energy storage systems (ESSs) are acknowledged to be a promising option to cope with issues in high penetration of renewable energy and guarantee a highly reliable power supply. In this paper, a two-step optimal allocation model is proposed to obtain the optimal allocation (location and size) of stationary ESSs (SESSs) and mobile ESSs (MESSs) in the resilient distribution networks (DNs). In the first step, a mixed-integer linear programming (MILP) problem is formulated to obtain the preselected location of ESSs with consideration of different scenarios under normal operation conditions. In the second step, a two-stage robust optimization model is established to get the optimal allocation results of ESSs under failure operation conditions which are solved by column-and-constraint generation (C&CG) algorithm. A hybrid ESS allocation strategy based on the subjective and objective weight analysis is proposed to give the final allocation scheme of SESSs and MESSs. Finally, the proposed two-step optimal allocation model is demonstrated on a modified IEEE 33-bus system to show its effectiveness and merits.

关键词： Resilient distribution network stationary energy storage system mobile energy storage system optimal allocation

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