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Fully distributed dynamic event-triggered formation-containment tracking for multiagent systems with multiple types of disturbances

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Science China(Information Sciences) 2024年第1期67卷 168-186页

作者： weihua li Huaguang ZHANG Juan ZHANG Rui WANG College of Information Science and Engineering Northeastern University State Key Laboratory of Synthetical Automation for Process Industries Northeastern University

This paper is dedicated to addressing the time-varying output formation-containment tracking(TVOFCT) problem for heterogeneous linear multiagent systems(MASs) with multiple types of disturbances under directed communication topology.The agents are divided into tracking leaders,formation leaders,and followers.In the output space,the formation leaders are required to form an expected geometric formation while tracking the tracking leader,and the followers are required to enter the convex hull spanned by formation leaders.First,a disturbance observer is designed to observe the disturbance with deterministic dynamics.Then,by combining adaptive technology with event-triggered technology,an independent fully distributed dynamic event-triggered(FDDET) compensator is designed to estimate the state of the tracking leader.The main advantages of this compensator lie in the following three aspects:(1) the adaptive weight does not increase unboundedly;(2) the interval time between events is expanded;(3) the design does not rely on any global information.Similar to the design of this compensator,an independent FDDET convex hull observer is further designed to observe the convex hull spanned by formation leaders.Subsequently,based on the designed disturbance observer,compensator,and convex hull observer,the adaptive disturbance rejection control input which can make the MASs achieve TVOFCT is formulated.Finally,a numerical simulation is provided to clearly verify the validity of the theoretical results.

关键词： formation-containment tracking disturbance rejection multiagent systems fully distributed control dynamic event-triggered control

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Interactive method research of dual mode information coordination integration for astronaut gesture and eye movement signals based on hybrid model

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Science China(Technological Sciences) 2023年第6期66卷 1717-1733页

作者： ZHUANG HongChao XIA YiLu WANG Ning li weihua DONG Lei li Bo School of Mechanical Engineering Tianjin University of Technology and EducationTianjin 300222China School of Information Technology Engineering Tianjin University of Technology and EducationTianjin 300222China School of Automotive Engineering Harbin Institute of Technology(Weihai)Weihai 264209China Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin 300458China School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150000China

The lightweight human-robot interaction model with high real-time,high accuracy,and strong anti-interference capability can be better applied to future lunar surface exploration and construction work.Based on the feature information inputted from the monocular camera,the signal acquisition and processing fusion of the astronaut gesture and eye-movement modal interaction can be performed.Compared with the single mode,the human-robot interaction model of bimodal collaboration can achieve the issuance of complex interactive commands more efficiently.The optimization of the target detection model is executed by inserting attention into YOLOv4 and filtering image motion blur.The central coordinates of pupils are identified by the neural network to realize the human-robot interaction in the eye movement mode.The fusion between the astronaut gesture signal and eye movement signal is performed at the end of the collaborative model to achieve complex command interactions based on a lightweight model.The dataset used in the network training is enhanced and extended to simulate the realistic lunar space interaction environment.The human-robot interaction effects of complex commands in the single mode are compared with those of complex commands in the bimodal collaboration.The experimental results show that the concatenated interaction model of the astronaut gesture and eye movement signals can excavate the bimodal interaction signal better,discriminate the complex interaction commands more quickly,and has stronger signal anti-interference capability based on its stronger feature information mining ability.Compared with the command interaction realized by using the single gesture modal signal and the single eye movement modal signal,the interaction model of bimodal collaboration is shorter about 79%to 91%of the time under the single mode interaction.Regardless of the influence of any image interference item,the overall judgment accuracy of the proposed model can be maintained at about 83%to 97%.The effectiveness of the propo

关键词： human-robot interaction gesture and eye movement hybrid model YOLOv4 CBAM

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Research progresses of nanomaterials as lubricant additives

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Friction 2024年第7期12卷 1347-1391页

作者： Zhengquan JIANG Yankun SUN Bokang liU Laigui YU Yuping TONG Mingming YAN Zhongzheng YANG Yongxing HAO linjian SHANGGUAN Shengmao ZHANG weihua li School of Materials Science and Engineering North China University of Water Resources and Electric PowerZhengzhou 450045China Institute of Special Friction and Lubricating Materials North China University of Water Resources and Electric PowerZhengzhou 450045China Nanomaterials Engineering Research Center Henan UniversityKaifeng 475001China School of Mechanical Engineering North China University of Water Resources and Electric PowerZhengzhou 450045China

Friction and wear are unavoidable in mechanical movement.The use of lubricants with nano-additives can effectively reduce friction and wear,which is of great significance to saving energy and protecting the environment.At present,great progress has been made in the scientific research and industrial application of nano-additives for lubricants.This paper mainly introduces the types of nano-additives for lubricants(such as carbon nanomaterials,nano-metals,nano-oxides,sulfides,complexes,polymers,etc.),the tribological properties of lubricants with different components of nano-additives,and the lubrication mechanisms of the nano-additives(including tribofilm formation,rolling ball bearing effect,repairing effect,polishing effect,and synergistic effect).It also deals with the dispersion of nano-additives in lubricants and the influences of their particle size and microstructure on the tribological properties of lubricants.This review outlines the performance requirements of nano-additives in different lubrication states,discusses the use of nano-additives in challenging working conditions,and identifies various industrial oil nano-additives with reference to the appropriate options in diverse working environments.Furthermore,the existing problems of nano-additives and their application prospects are summarized.This review,hopefully,would help to shed light on the design and synthesis of novel high-performance nano-additives and promote their application in engineering.

关键词： nanomaterials lubricant additive lubrication mechanism research progress

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Effect of Polyaniline/manganese Dioxide Composite on the Thermoelectric Effect of Cement-based Materials

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Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 109-116页

作者：季涛 liAO Xiao HE Yan 张士萍 ZHANG Xiaoying ZHANG Xiong li weihua School of Architecture and Civil Engineering Nanjing Institute of TechnologyNanjing 211167China College of Civil Engineering Qingdao University of TechnologyQingdao 266033China School of Civil Engineering Suzhou University of Science and TechnologySuzhou 215011China School of Materials Science and Engineering Tongji UniversityShanghai 201804China School of Chemical Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

To enhance the thermoelectric effect of cement-based materials,conductive polyaniline(PANI)modified MnO_(2)powder was synthesized and used as a thermoelectric component in the cement composites.The nanostructured PANI was deposited on the surface of the nanorod-shapedα-MnO_(2)particle and the weight ratio of PANI to MnO_(2)was 22.3:77.7 in the composite.The synthesized PANI/MnO_(2)composite was nanostructured according to the SEM image.The test results of the thermoelectric properties proved that the PANI/MnO_(2)composite was effective as the Seebeck coefficient and electrical conductivity values of the cement composites with PANI/MnO_(2)inside were 3-4 orders of magnitude higher than those of pure cement paste and the thermal conductivity values of these cement samples were similar.The obtained maximum figure of merit(ZT)value(2.75×10^(-3))was much larger than that of conductive materials reinforced cement-based composites.The thermoelectric effect of cement composites is mainly enhanced by the increased Seebeck coefficient and electrical conductivity in this work.

关键词： PANI/MnO_(2)composite cement composites thermoelectric effect Seebeck coefficient electrical conductivity

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Deep Contextual Representation Learning for Identifying Essential Proteins via Integrating Multisource Protein Features

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Chinese Journal of Electronics 2023年第4期32卷 868-881页

作者： li weihua liU Wenyang GUO Yanbu WANG Bingyi QING Hua School of Information Science and Engineering Yunnan University College of Software Engineering Zhengzhou University of Light Industry Institute of Highland Forest Science Chinese Academy of Forestry

Essential proteins with biological functions are necessary for the survival of organisms. Computational recognition methods of essential proteins can reduce the workload and provide candidate proteins for biologists. However, existing methods fail to efficiently identify essential proteins, and generally do not fully use amino acid sequence information to improve the performance of essential protein recognition. In this work, we propose an end-to-end deep contextual representation learning framework called DeepIEP to automatically learn biological discriminative features without prior knowledge based on protein network heterogeneous information. Specifically, the model attaches amino acid sequences as the attributes of each protein node in the protein interaction network, and then automatically learns topological features from protein interaction networks by graph embedding algorithms. Next, multi-scale convolutions and gated recurrent unit networks are used to extract contextual features from gene expression profiles. The extensive experiments confirm that our DeepIEP is an effective and efficient feature learning framework for identifying essential proteins and contextual features of protein sequences can improve the recognition performance of essential proteins.

关键词： Essential proteins Protein interaction networks Gene expression profile Deep neural networks

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On ultraproducts of operator algebras

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Science China Mathematics 2005年第9期48卷 1284-1295页

作者： li weihua Institute of Mathematics Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100080 China

Some basic questions on ultraproducts of C*-algebras and yon Neumann algebras, including the relation to K-theory of C*-algebras are considered. More specifically,we prove that under certain conditions, the K-groups of ultraproduct of C*-algebras are isomorphic to the ultraproduct of respective K-groups of C*-algebras. We also show that the ultraproducts of factors of type Ⅱ1 are prime, i.e. not isomorphic to any non-trivial tensor product.

关键词： von Neumann algebras, C*-algebras, ultraproducts,K-group, double commutants.

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Some basic principles in dynamic theory of viscoelastic materials with voids

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Science China(Physics,Mechanics & Astronomy) 2007年第3期50卷 370-378页

作者： LUO En li weihua Department of Applied Mechanics and Engineering Sun Yat-sen UniversityGuangzhou 510275China

According to the basic idea of classical yin-yang complementarity and modern dual-complementarity, in a simple and unified way proposed by Luo, some basic principles in the dynamic theory of viscoelastic materials with voids can be estab- lished systematically. In this paper, an important integral relation in terms of con- volutions is given, which can be considered as the generalized principle of virtual work in mechanics. Based on this relation, it is possible not only to obtain the principle of virtual work and the reciprocal theorem, but also to derive systemati- cally the complementary functionals for the eight-field, six-field, four-field simpli- fied Gurtin-type variational principles and the potential energy-functional for the two-field one in the dynamic theory of viscoelastic materials with voids by the generalized Legendre transformations given in this paper. Furthermore, with this approach, the intrinsic relationship among various principles can be explained clearly.

关键词： dynamic theory of viscoelastic materials with voids principle of virtual work reciprocal theorem simplified Gurtin-type variational principle complementary relation

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Different quasispecies with great mutations hide in the same subgroup J field strain of avian leukosis virus

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Science China(life Sciences) 2013年第5期56卷 414-420页

作者： MAO YaQing li weihua DONG Xuan liU JinHua ZHAO Peng College of Veterinary Medicine China Agricultural University China Institute of Veterinary Drug Control College of Veterinary Medicine Shandong Agricultural University

Blood samples were collected from a local strain of chickens associated with serious tumor cases in Shandong Province.The samples were inoculated into chicken embryo fibroblast and DF-1 cells for virus isolation and identification,respectively.The inoculated cells were screened for three common chicken tumor viruses.Nine strains of avian leukosis virus subgroup J(ALV-J) were identified,and were designated LY1201‐LY1209.The env gene from the LY1201 strain was amplified and cloned.All nine resultant env clones(clones 01-09) were sequenced,and the gp85 and gp37 amino acid regions were subjected to homology analysis.Clones 01 and 03 had 10 amino acid deletions in the gp85 region compared to the other seven clones,suggesting that at least two quasispecies with obvious mutations coexist in the same field strain.Among these nine clones,three had identical gp85 and gp37 sequences,and were recognized as the dominant LY1201 quasispecies.The amino acid sequence homology of gp37 and gp85 among the nine clones was 98.5%-100.0% and 96.6%-100.0% respectively,suggesting that the gp85 region of the env gene can better display the quasispecies diversity of ALV-J than gp37.

关键词： J亚群禽白血病病毒准种鸡胚成纤维细胞突变野毒株禽白血病病毒J亚群氨基酸序列 ALV-J

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薄壁零件铣削的磁流变弹性体吸振器的理论分析及试验

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机械科学与技术 2022年第2期41卷 263-269页

作者：杨清艳 li weihua 安徽建筑大学机械与电气工程学院合肥230601 College of Engineering and Information Sciences University of Wollongong Wollongong 2500 Australia

薄壁件由于刚性差,在铣削过程中难免会出现各种扰动,从而容易发生颤振,严重影响了加工零件的精度和表面质量。为了解决该问题,考虑到同种材料不同尺寸的工件,或者不同材料的工件其固有频率不同,提出了在加工过程采用变频率的磁流变吸振... 详细信息

薄壁件由于刚性差,在铣削过程中难免会出现各种扰动,从而容易发生颤振,严重影响了加工零件的精度和表面质量。为了解决该问题,考虑到同种材料不同尺寸的工件,或者不同材料的工件其固有频率不同,提出了在加工过程采用变频率的磁流变吸振器(Magneto rheological elastomer(MRE)absorber)的方法。文中详细介绍了磁流变吸振器的设计过程,并对吸振器的在不同电流下的频率进行测试,分析了磁流变吸振器在铣削加工中使用性能,对比铣削系统的稳定性叶瓣图及抗干扰的能力。结果表明所设计的变频率磁流变吸振器对于防止切削颤振是可行的,并且可以通过改变通电电流将其应用于不同材料的工件,不同尺寸的工件。

关键词：铣削磁流变弹性体吸振器薄壁零件振动

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A modified version of free orbit-dimension of von Neumann algebras

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Science China Mathematics 2011年第11期54卷 2329-2346页

作者： HADWIN Don li weihua Mathematics Department University of New Hampshire Durham NH 03824 USA Science and Mathematics Department Columbia College Chicago Chicago IL 60605 USA

Based on the notion of free orbit-dimension of Hadwin-Shen (2007) we introduce a new invariant for finite von Neumann algebras with arbitrarily large generating sets and acting on Hilbert spaces of arbitrary dimension. We show that this invariant is independent of the generating set, and we extend results in Hadwin-Shen (2007) to this larger class of algebras.

关键词：代数轨道 Hilbert空间免费版本修改发电机组不变量

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