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Jiangsu Annual Conference on Automation (JACA 2022)

作者： Y. Ni C. Yang X. Liu X. Luan F. Liu The Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education) School of Internet of Things Engineering Jiangnan University Wuxi People's Republic of China The Key Laboratory of Smart Manufacturing in Energy Chemical Process (Ministry of Education) Department of Automation East China University of Science and Technology Shanghai People's Republic of China Department of Radiology Athinoula A. Martinos Center for Biomedical Imaging Massachusetts General Hospital/Harvard Medical School Boston USA

In this paper we focus on the sensor scheduling for dynamic state estimation among multiple processes. Multiple sensors transmit their measurements to the remote estimator via a shared wireless channel. Only a subset of sensors are allowed to transmit at each time. The objective of the scheduler is to maximize a linear combination of the terminal time estimation error covariances in a log-determinant sense. We develop conditions under which the objective is monotone and submodular. A submodularity-based greedy scheduling algorithm is proposed, and its performance bound is provided. Numerical examples are presented to illustrate the theoretical findings.

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Study on establishment of standardized load spectrum on bogie frames of high-speed trains

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Acta Mechanica Sinica 2019年第4期35卷 812-827页

作者： Daoyun Chen Qian Xiao Minghui Mou Shouguang Sun Qiang Li Key Laboratory of Conveyance and Equipment (Ministry of Education) East China Jiaotong UniversityNanchang 330013 China Modern Educational and Technological Center East China Jiaotong University Nanchang 330013 China Key Laboratory of Vehicle Advanced Manufacturing Measuring and Control Technology(Ministry of Education) Beijing Jiaotong University Beijing 100044 China

Establishing structural load spectrum under actual operating conditions is a major problem in structural fatigue life analysis. This study introduces the load measuring method for the bogie frame structure. The load-measuring frame based on quasi-static can measure different load systems synchronously. The t-test method is employed to evaluate the least test time of deducing the parent distribution. In order to fit the load spectrum distribution accurately, the kernel density estimation method is employed which is based on the sample characteristics. The expansion factor method is used to deduce the maximum load. The formula of standardized load spectrum derives from the deduced maximum load, the linear factor between operating condition length and cumulative frequency and the parent distribution of each load system. The damage consistency criterion is performed by solving the objective function with constraint conditions. The calibrated damage provides a suitable representation of the real damage under actual operating conditions. By processing and analyzing the load spectrum and stress spectrum data of the measured lines, it is verified that the standardized load spectrum established in this paper is superior to the European specification and the Japanese specification in evaluating the fatigue reliability of the structure.

关键词： Load spectrum Bogie frame Kernel density Expansion factor Damage calibration

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Self-Activation via Heteroatomic Removal Strategy for the Synthesis of Intrinsic Defect-rich Hierarchical Porous Carbon towards advanced Supercapacitors

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Surfaces and Interfaces 2025年

作者： Chuixiong Kong Yuan Ma Tingmin Di Geming Wang Quanrong Deng Shenggao Wang Yuan Gao Zurong Du Provincial Key Laboratory of Plasma Chemistry and Advanced Materials Wuhan Institute of Technology Wuhan 430073 PR China Department of Intelligent Manufacturing and Equipment GuiZhou Vocational Technology College of Electronics & Information Kaili 556000 PR China Hubei key laboratory of automotive power train and electronic control College of automotive engineering Hubei University of Automotive technology Shiyan 442002 PR China

Porous carbon materials have garnered significant attention as electrodes for supercapacitors due to their substantial specific surface area, notable electrical conductivity, and commendable chemical stability. Current research primarily focuses on the effect of heteroatom doping on the active sites of carbon materials. However, less attention is given to the role of intrinsic defects, which result from heteroatom removal, in enhancing the energy storage performance of carbon materials. Herein, a series of intrinsic defect-rich hierarchical porous carbon materials (D-HPCs) are fabricated through the integration of sealed high-pressure carbonization and high-temperature self-activation strategies. The experimental results show that the elimination of heteroatoms positively affects the development of the porous structure and the formation of high concentration of intrinsic defects in carbon materials. The presence of abundant intrinsic defects significantly enhances the capacitive behavior, and there is a positive correlation between the concentration of intrinsic defects and the utilization ratio of specific surface area/electrical double-layer capacitance. With an optimized intrinsic defect-rich hierarchical pore structure, the D-HPC-950-based supercapacitor achieves high energy density (15.8 Wh kg –1 at 250 W kg –1 ) and excellent cycling stability (retention of 101.6% after 10,000 cycles). This study provides a new perspective for the design and optimization of porous carbon electrode materials, with the developed methodology expecting to be extended to other energy storage systems and related fields.

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Contact Model And Simulation Analysis of Rail Grinding With Open-Structured Abrasive Belt Based On Pressing Plate

Research Square

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Research Square 2021年

作者： Qian, Chang Wu, Zhiwei Hou, Guangyou Fan, Wengang School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing100044 China Key Laboratory of Vehicle Advanced Manufacturing Measuring and Control Technology Ministry of Education Beijing100044 China Railway Engineering Research Institute China Academy of Railway Sciences Beijing100081 China

Recently, the emerging rail grinding method with open-structured abrasive belt based on pressing plate which adopts full contour copying grinding method to extend the working length of abrasive belt and is more suitable for preventative grinding and maintenance of rail corrugation in high-speed railway has been proposed. The essence of its grinding process is the complex nonlinear interaction among the pressing plate, abrasive belt and rail. The research on the contact mechanism of the rail grinding method with open-structured abrasive belt based on pressing plate is still very lacking, which limits the practical application of the emering rail grinding method to a certain extent. In this paper, a theoretical model of the contact between pressing plate, abrasive belt and rail is established. The contact area morphology and contact stress distribution were obtained, and validity of the theoretical model was verified by finite element simulation. At the same time, the distribution characteristics of contact stress under single concentrated force, uniform force and multiple concentrated force were studied based on the contact model. It is concluded that the multiple concentrated force is the optimal loading method, and the contact stress is more uniform, which is more conducive to repair the standard contour of rail. © 2021, CC BY.

关键词： Railroad transportation

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Time-Switching Energy Harvesting Relay Optimizing Considering Decoding Cost 9th

Time-Switching Energy Harvesting Relay Optimizing Considerin...

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9th EAI International Conference on Cloud Computing, CloudComp 2019 and the 4th EAI International Conference on Smart Grid and Innovative Frontiers in Telecommunications, SmartGIFT 2019

作者： Hu, Wanqiu Yao, Yanxin Ni, Zhengwei Bhat, Rajshekhar V. Motani, Mehul Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Advanced Equipment Intelligent Perception and Control Beijing International Cooperation Base for Science and Technology Beijing Information Science and Technology University Beijing100190 China Zhejiang Gongshang University Zhejiang310018 China Indian Institute of Technology Dharwad Dharwad India National University of Singapore Singapore Singapore

ISBN: (纸本)9783030485122

Energy harvesting (EH) from natural and man-made sources is of prime importance for enabling the Internet of Things (IoT) networks. Although, energy harvesting relays in a relay network, which form building blocks of an IoT network, have been considered in the literature, most of the studies do not account for the processing costs, such as the decoding cost in a decode-and-forward (DF) relay. However, it is known that the decoding cost amounts to a significant fraction of the circuit power required for receiving a codeword. Hence, in this work, we are motivated to consider an EH-DF relay with the decoding cost and maximize the average number of bits relayed by it with a time-switching architecture. To achieve this, we first propose a time-switching frame structure consisting of three phases: (i) an energy harvesting phase, (ii) a reception phase and, (iii) a transmission phase. We obtain optimal length of each of the above phases and communication rates that maximize the average number of bits relayed. We consider two EH scenarios, (a) when the radio frequency (RF) energy, to be harvested by the relay, is transmitted from a dedicated transmitter, and (ii) when the energy is harvested at the rely from the ambient environment. By exploiting the convexity of the optimization problem, we derive analytical optimum solutions under the above two scenarios and provide numerical simulations for verifying our theoretical analysis. © 2020, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

关键词： Energy harvesting

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Multiple Time Blocks Energy Harvesting Relay Optimizing with Time-Switching Structure and Decoding Cost 9th

Multiple Time Blocks Energy Harvesting Relay Optimizing with...

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9th EAI International Conference on Cloud Computing, CloudComp 2019 and the 4th EAI International Conference on Smart Grid and Innovative Frontiers in Telecommunications, SmartGIFT 2019

作者： Wang, Chenxu Yao, Yanxin Ni, Zhengwei Bhat, Rajshekhar V. Motani, Mehul Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Advanced Equipment Intelligent Perception and Control Beijing International Cooperation Base for Science and Technology Beijing Information Science and Technology University Beijing100190 China Zhejiang Gongshang University HangzhouZhejiang310018 China Indian Institute of Technology Dharwad Dharwad India National University of Singapore Singapore Singapore

ISBN: (纸本)9783030485122

Energy harvesting (EH) is of prime importance for enabling the Internet of Things (IoT) networks. Although, energy harvesting relays have been considered in the literature, most of the studies do not account for the processing costs, such as the decoding cost in a decode-and-forward (DF) relay. However, it is known that the decoding cost amounts to a significant fraction of the circuit power required for receiving a codeword. Hence, in this work, we are motivated to consider an EH-DF relay with the decoding cost and maximize the average number of bits relayed by it with a time-switching architecture. To achieve this, we first propose a time-switching frame structure consisting of three phases: (i) an energy harvesting phase, (ii) a reception phase and, (iii) a transmission phase. We obtain optimal length of each of the above phases and communication rates that maximize the average number of bits relayed. We consider the radio frequency (RF) energy to be harvested by the relay is from the dedicated transmitter and the multiple block case when energy is allowed from flow among the blocks, different from the single block case when energy is not allowed to flow among the blocks. By exploiting the convexity of the optimization problem, we derive analytical optimum solutions under the EH scenario. One of the optimal receiving rate for the relay is the same as in single block case. We also provide numerical simulations for verifying our theoretical analysis. © 2020, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

关键词： Energy harvesting

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Ultrasonic flexible microextrusion forming of ZK60 Mg alloy at room temperature 2

Ultrasonic flexible microextrusion forming of ZK60 Mg alloy ...

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2nd International Symposium on Application of Materials Science and Energy Materials, SAMSE 2018

作者： Lou, Yan Liu, Xiao Shenzhen Key Laboratory of Advanced Manufacturing Technology for Mold and Die College of Mechatronics and Control Engineering Shenzhen University Shenzhen518060 China

A novel method of ZK60 magnesium formed through ultrasonic flexible microextrusion at room temperature was developed. A self-designed apparatus was applied for the ultrasonic flexible microextrusion experiments. The results showed that the forming ability and surface quality of products was improved via ultrasonic flexible microextrusion forming method. The extrusion stress distribution could be more uniform by using ultrasonic plasticizing flexible punch, compared with rigid punch. © Published under licence by IOP Publishing Ltd.

关键词： Magnesium alloys

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Type-Ⅱ topological metals

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物理学前沿 2020年第4期15卷 98-109页

作者： Si Li Zhi-Ming Yu Yugui Yao Shengyuan A.Yang Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of Physics and Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal University Changsha 410081 China Research Laboratory for Quantum Materials Singapore University of Technology and Design Singapore 487372 Singapore Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE) Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems and School of Physics Beijing Institute of Technology Beijing 100081 China

Topological metals (TMs) are a kind of special metallic materials,which feature nontrivial band crossings near the Fermi energy,giving rise to peculiar quasiparticle *** can be classified based on the characteristics of these band *** example,according to the dimensionality of the crossing,TMs can be classified into nodal-point,nodal-line,and nodal-surface *** important property is the type of *** to degree of the tilt of the local dispersion around the crossing,we have type-Ⅰ and type-Ⅱ *** leads to significant distinctions in the physical properties of the materials,owing to their contrasting Fermi surface *** this article,we briefly review the recent advances in this research direction,focusing on the concepts,the physical properties,and the material realizations of the type-Ⅱ nodal-point and nodal-line TMs.

关键词： type-Ⅱ nodal point nodal line topological metals

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Finite Element Analysis of Series Elastic Actuator for Exoskeleton Robot Joint 17

Finite Element Analysis of Series Elastic Actuator for Exosk...

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17th IEEE International Conference on Mechatronics and Automation, ICMA 2020

作者： Xi, Pengyu Ge, Weimin Zhang, Sen Zhang, Zhili Zielinska, Teresa Tianjin University of Technology Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin300384 China Tianjin Sino-German University of Applied Science Intelligent Manufacturing College Tianjin300384 China Institute of Aeronautics and Applied Mechanics Warsaw University of Technology Warsaw00665 Poland

ISBN: (纸本)9781728164151

The finite element simulation for the joints of an exoskeleton robot is conducted in this paper. Using software OpenSim to simulate the normal walking gait of the human body, the motion angle and moment of the human hip, knee and ankle joints are obtained. Using the obtained data as the input parameters in the finite element simulation of the simulation software Ls-dyna, the strain diagrams and contact force curves of the circular roller and cam disk were obtained. In this study, three commonly used materials are selected: alloy steel, ductile iron and hard aluminum alloy. Finally, the effects of different materials on the key components of the series elastic actuator are studied. © 2020 IEEE.

关键词： Finite element method

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Effect of the Crosslinking Degree on the Microstructure and Thermomechanical Properties of a Polymer Grouting Material

SSRN

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SSRN 2022年

作者： Yuan, Lingxiu Zhang, Chao Wang, Cuixia Wei, Ning Wan, Jing Zhu, Chunhua Fang, Hongyuan Shi, Mingsheng School of Water Conservancy Engineering Zhengzhou University Zhengzhou450001 China National Local Joint Engineering Laboratory of Major Infrastructure Testing and Rehabilitation Technology Zhengzhou450001 China Collaborative Innovation Center for Disaster Prevention and Control of Underground Engineering Jointly Built by Provinces and Ministries Henan Province Zhengzhou450001 China Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology Jiangnan University Wuxi214122 China School of Mechanics and Safety Engineering Zhengzhou University Zhengzhou450001 China

Polymer grouting materials are widely used in the field of trenchless rehabilitation of infrastructure, and their properties are closely related to the crosslinking process and crosslinking degree between components. In this paper, polyurethane (PU) models with different crosslinking degrees were built based on the molecular dynamics (MD) simulations method and Python script. We investigated the crosslinking reaction process of PU grouting materials and the effect of their crosslinking degree on the glass transition temperature (Tg) and tensile properties. Also, the rationality of the model was verified by comparing the Tg obtained in the simulation and experiment. The results showed that the crosslinking reaction is a volume shrinkage process, and the PU model has a good network structure. The non-bonding energy is the main reason for the variation in the Tg, which increased with increasing crosslinking degree. Besides, the tensile properties of PU are greatly affected by the crosslinking degree, and the elastic modulus increased with increasing crosslinking degree. The results are of great significance for understanding the microstructure and thermomechanical properties of PU grouting materials at the molecular level. © 2022, The Authors. All rights reserved.

关键词： Microstructure

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