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On the leader-following exponential consensus of discrete-time linear multi-agent systems over jointly connected switching networks

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Control Theory and Technology 2023年第3期21卷 469-477页

作者： Tao Liu jie huang Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055GuangdongChina Shenzhen Research Institute The Chinese University of Hong KongShenzhen 518057GuangdongChina Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

The leader-following asymptotic consensus problem for general discrete-time linear multi-agent systems over jointly con-nected switching networks was solved about a decade ***,the leader-following exponential consensus was further established using the so-called Krasovskii-LaSalle theorem for a class of discrete-time linear switched *** this method involves some advanced concepts such as the weak zero-state detectability of some limiting *** this paper,we offer a simpler solution to the leader-following exponential consensus problem for general discrete-time linear multi-agent systems over jointly connected switching *** converting the solvability of the problem to the establishment of the exponential stability for a class of discrete-time linear switched systems,we first show that this class of linear switched systems is uniformly completely ***,we further conclude that the uniform complete observability for this class of linear switched systems implies the exponential stability for the same class of linear switched systems,thus leading to the solution of the leader-following exponential consensus ***,our approach also gives rise to an explicit characterization of the exponential convergence rate of the leader-following consensus problem.

关键词： Leader-following consensus Exponential stabilization-Linear switched systems Discrete-time systems

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定窑遗址出土制瓷原料的科学分析

光谱学与光谱分析 2025年第1期45卷 72-81页

作者：陈殿崔剑锋秦大树黄信李鑫北京师范大学历史学院陶瓷考古与艺术研究中心北京100875 考古科学教育部重点实验室(北京大学) 北京100871 浙大城市学院考古学系浙江杭州310015 河北省文物考古研究院河北石家庄050031 中国社会科学院考古研究所北京100101

首次通过窑址发掘出土的制瓷原料,复原了定窑不同时代的胎釉配方。对2009年定窑作坊遗址考古发掘所出五代至宋金时期二十余种制瓷原料开展了ED-XRF成分分析和XRD结构分析等光谱学分析。ED-XRF成分分析显示,这些原料可能包括单一原料和... 详细信息

首次通过窑址发掘出土的制瓷原料,复原了定窑不同时代的胎釉配方。对2009年定窑作坊遗址考古发掘所出五代至宋金时期二十余种制瓷原料开展了ED-XRF成分分析和XRD结构分析等光谱学分析。ED-XRF成分分析显示,这些原料可能包括单一原料和混合原料两种。其中单一原料包括岩石、粘土以及草木灰。混合原料则包括胎料和釉料两种。XRD结构分析表明用于定窑白瓷生产高岭土类原料是含有蒙脱石和方解石的伴生石英的长石类矿物原料。高铁粘土类原料由于铁含量特别高,应当是用于配黑釉的粘土。钙质原料的分析与康葆强等学者对定窑配釉用的灰料可能使用了40%的白灰和60%的松木灰配制的结论相同。同时,还发现了釉灰,即草木煅烧石灰石后形成的混合灰料。在分析定窑白瓷釉时,认为五代的白瓷釉可能使用了釉灰配制,因此定窑釉灰的使用可能推早到五代,这是目前发现使用釉灰配釉最早的实例。对制胎原料XRD晶相分析的结果表明,除了石英和高岭石占主要比重外,还含有长石、蒙脱石、方解石等岩石类矿物。从对单一原料的X射线衍射的分析结果看,石英是粘土以及岩石这类单一原料中都含有的一类矿物,因此可能石英并非必须要添加的胎体原料。石英和高岭石是粘土原料中的主要成分,因此制胎原料应该主要以岩石类原料和粘土作为主要配料。定窑细白瓷胎料可能使用了粘土类原料配合第一类岩石类原料的配方,其配比在金代时大约为1∶1左右,北宋时期可能约为7∶3(粘土∶岩石),五代时大概为6∶4左右。对制釉原料分析结果表明,定窑配釉原料是岩石类原料与釉灰配合形成的,五代、北宋时岩石和灰的比例约为9∶1,金代时石:灰达到了9.5∶0.5。这使得我们对定窑鼎盛时期的白瓷胎釉配方有了更加清晰的了解,从而为开展定窑的复烧提供了确凿的依据。

关键词：定窑制瓷原料光谱学分析

FDTD analysis of the optical properties of vertical ZnO nanorod array

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Science China(Technological Sciences) 2014年第6期57卷 1147-1153页

作者： shu Yue YE Hong CHEN jie Department of Thermal Science and Energy Engineering University of Science and Technology of China National Institute of Clean-and-Low-Carbon Energy (NICE)

Based on the structure and dimensions of a vertical ZnO nanorod array(V-ZNA)sample,an ideal 2-D photonic crystal model was *** optical properties of the V-ZNAs were analyzed with finite-difference time-domain(FDTD)method,and the influences of the geometry parameters,including the circumcircle diameters of the top and bottom surfaces(Dt and Db)and the height(H)of the nanorods,and the pitch between each column(L),were *** transmittance and low reflectance in the waveband of 400–800 nm were proved,and the highest transmittance can be obtained with Dt<50 nm,H=200 nm,and Db/L=0.85,which was verified by Effective Index Method(EIM).The result indicates that V-ZNAs can be used as excellent light coupling element and antireflection material for solar energy applications.

关键词： V-ZNAs FDTD method transmittance reflectance EIM

The Climate Response to Global Forest Area Changes under Different Warming Scenarios in China

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Advances in Atmospheric Sciences 2023年第6期40卷 1073-1088页

作者： Ying huang Anning huang jie TAN School of Atmospheric Sciences Nanjing UniversityNanjing 210023China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing 210023China Glarun Technology Co. Ltd.Nanjing 211106China

Human activities have notably affected the Earth’s climate through greenhouse gases(GHG), aerosol, and land use/land cover change(LULCC). To investigate the impact of forest changes on regional climate under different shared socioeconomic pathways(SSPs), changes in surface air temperature and precipitation over China under low and medium/high radiative forcing scenarios from 2021 to 2099 are analyzed using multimodel climate simulations from the Coupled Model Intercomparison Project Phase 6(CMIP6). Results show that the climate responses to forest changes are more significant under the low radiative forcing scenario. Deforestation would increase the mean, interannual variability, and the trend of surface air temperature under the low radiative forcing scenario, but it would decrease those indices under the medium/high radiative forcing scenario. The changes in temperature show significant spatial heterogeneity. For precipitation, under the low radiative forcing scenario, deforestation would lead to a significant increase in northern China and a significant decrease in southern China, and the effects are persistent in the near term(2021–40), middle term(2041–70), and long term(2071–99). In contrast, under the medium/high radiative forcing scenario, precipitation increases in the near term and long term over most parts of China, but it decreases in the middle term, especially in southern, northern,and northeast China. The magnitude of precipitation response to deforestation remains comparatively small.

关键词： land use/land cover change deforestation radiative forcing scenario regional climate

Hierarchical Covering Algorithm

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Tsinghua Science and Technology 2014年第1期19卷 76-81页

作者： jie Chen shu Zhao Yanping Zhang Department of Computer Science and Technology and Key Lab of Intelligent Computing and Signal Processing Anhui University

The concept of deep learning has been applied to many domains, but the definition of a suitable problem depth has not been sufficiently explored. In this study, we propose a new Hierarchical Covering Algorithm （HCA） method to determine the levels of a hierarchical structure based on the Covering Algorithm （CA）. The CA constructs neural networks based on samples＇ own characteristics, and can effectively handle multi-category classification and large-scale data. Further, we abstract characters based on the CA to automatically embody the feature of a deep structure. We apply CA to construct hidden nodes at the lower level, and define a fuzzy equivalence relation R on upper spaces to form a hierarchical architecture based on fuzzy quotient space theory. The covering tree naturally becomes from R. HCA experiments performed on MNIST dataset show that the covering tree embodies the deep architecture of the problem, and the effects of a deep structure are shown to be better than having a single level.

关键词： deep architecture hierarchy fuzzy equivalence relation covering tree MNIST dataset

Multiple Solutions for a Fourth-order Asymptotically Linear Elliptic Problem

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1121-1126页

作者： Ai Xia QIAN shu jie LI Department of Mathematics Qufu Normal University Qufu 273165 P. R. China Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 P. R. China

Under simple conditions, we prove the existence of three solutions for a fourth-order asymptotically linear elliptic boundary value problem. For the resonance case at infinity, we do not need to assume any more condit... 详细信息

关键词： Fourth-order elliptic boundary value problem Mountain Pass theorem Morse theory

AN ALTERNATIVE APPROACH TO GLOBAL ROBUST OUTPUT REGULATION OF OUTPUT FEEDBACK SYSTEMS

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Journal of Systems Science & Complexity 2007年第2期20卷 235-242页

作者： jie huang Department of Mechanical and Automation Engineering The Chinese University of Hong Kong Shatin N.T. Hong Kong China

The global robust output regulation problem of the output feedback systems has been extensively studied under various assumptions of the complexity and uncertainty. All these approaches boil down to a stabilization problem of a so-called augmented extended system. This paper will describe an alternative approach which converts the original problem into a stabilization problem of a so-called extended augmented system. As the extended augmented system is somewhat simpler than the augmented extended system, this alternative approach is also simpler than the first approach.

关键词： Adaptive control nonlinear systems output regulation

Adaptive distributed observer and the cooperative control of multi-agent systems

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Journal of Control and Decision 2017年第1期4卷 1-11页

作者： jie huang Department of Mechanical and Automation Engineering Chinese University of Hong KongShatinHong Kong

The distributed observer approach has been an effective way to synthesise a distributed control law for a multi-agent ***,this approach assumes that all the followers know the system matrix of the leader system,and this assumption may not be desirable in some *** this note,we will further introduce an adaptive distributed observer,which is able to estimate both the state and the system matrix of the leader and thus does not require that all the followers know the system matrix of the leader *** will also point out some applications of the adaptive distributed observer to several cooperative control problems of multiagent systems such as the leader-following consensus problem,the cooperative output regulation problem and rendezvous and/or flocking.

关键词： Adaptive distributed observer multi-agent systems distributed control cooperative control

Flowfield of a helicopter submerged inlet with power output shaft

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Acta Mechanica Sinica 2021年第1期37卷 156-168,I0003页

作者： He-Xia huang Hui-Jun Tan Zheng-Kang Lin Zi-jie Li shu Sun Hao Chen Zhi-Xiang Xiao Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China School of Aerospace Engineering Tsinghua UniversityBeijing100084China

The submerged inlet is an attractive configuration for advanced helicopters due to its high stealth performance and low external *** this paper,a submerged inlet,integrated with a ROBIN helicopter fuselage and a simplified power output shaft,is experimentally and numerically investigated to obtain the basic flow characteristics under a freestream velocity of 23.6 m/*** results indicate that the pylon ahead of the inlet induces a horseshoe *** the vortex is ingested into the inlet,it has little effect on the internal flows and can be *** the airflow enters into the inlet,it interacts with the shaft with a large incidence angle,yielding a vortex *** the leeside of the shaft,the two side flows of the shaft impinge at the center plane,generating a local high-pressure region at the azimuthal angle of 180°,which forces the boundary layer to roll up a counter-rotating vortex *** addition,the airflow adjacent to the cowl lip accelerates rapidly,resulting in a local low-pressure region at the azimuthal angle of 0°.Therefore,the inlet duct has a strong circumferential pressure gradient,which originates from an azimuthal angle of 180°to 0°and induces a vortex pair at the azimuthal angle of 0°.The three vortex pairs are the main origins of the distortion at the duct exit plane,among which the one near the cowl lip with the azimuthal angle of 0°plays the dominant ***,as the velocity ratio increases from 3.9 to 5.5,the circumferential pressure gradient and the cowl lip vortex get intensified,which causes that the total-pressure recovery coefficient drops by 0.5%and the distortion index increases by 28%.

关键词： Submerged inlet Helicopter Vortex pair