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New synchronization analysis for complex networks with variable delays

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Chinese Physics B 2011年第4期20卷 179-186页

作者：张化光宫大为王占山 college of information science and engineering Northeastern University

This paper deals with the issue of synchronization of delayed complex networks. Differing from previous results, the delay interval [0, d（t）] is divided into some variable subintervals by employing a new method of weighting delays. Thus, new synchronization criteria for complex networks with time-varying delays are derived by applying this weighting-delay method and introducing some free weighting matrices. The obtained results have proved to be less conservative than previous results. The sufficient conditions of asymptotical synchronization are derived in the form of linear matrix inequality, which are easy to verify. Finally, several simulation examples are provided to show the effectiveness of the proposed results.

关键词： complex networks synchronization time-varying delay weighting delay linear matrix inequality

An Incremental Model Transfer Method for Complex Process Fault Diagnosis

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1268-1280页

作者： Xiaogang Wang Xiyu Liu Yu Li college of information science and engineering Northeastern University

Fault diagnosis is an important measure to ensure the safety of production, and all kinds of fault diagnosis methods are of importance in actual production process. However, the complexity and uncertainty of production process often lead to the changes of data distribution and the emergence of new fault classes, and the number of the new fault classes is unpredictable. The reconstruction of the fault diagnosis model and the identification of new fault classes have become core issues under the circumstances. This paper presents a fault diagnosis method based on model transfer learning and the main contributions of the paper are as follows: 1) An incremental model transfer fault diagnosis method is proposed to reconstruct the new process diagnosis model. 2) Breaking the limit of existing method that the new process can only have one more class of faults than the old process, this method can identify M faults more in the new process with the thought of incremental learning. 3) The method offers a solution to a series of problems caused by the increase of fault classes. Experiments based on Tennessee-Eastman process and ore grinding classification process demonstrate the effectiveness and the feasibility of the method.

关键词： Complex process fault diagnosis incremental learning model transfer

Cluster exponential synchronization of a class of complex networks with hybrid coupling and time-varying delay

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Chinese Physics B 2013年第9期22卷 324-334页

作者：王军义张化光王占山梁洪晶 college of information science and engineering Northeastern University

This paper deals with the cluster exponential synchronization of a class ot complex networks wlm nyorm coupm^g and time-varying delay. Through constructing an appropriate Lyapunov-Krasovskii functional and applying the theory of the Kronecker product of matrices and the linear matrix inequality （LMI） technique, several novel sufficient conditions for cluster exponential synchronization are obtained. These cluster exponential synchronization conditions adopt the bounds of both time delay and its derivative, which are less conservative. Finally, the numerical simulations are performed to show the effectiveness of the theoretical results.

关键词： complex network cluster exponential synchronization linear matrix inequality time-varying de-lay

Novel pinning control strategies for synchronisation of complex networks with nonlinear coupling dynamics

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Chinese Physics B 2010年第9期19卷 250-260页

作者：刘兆冰张化光孙秋野 college of information science and engineering Northeastern University

This paper considers the global stability of controlling an uncertain complex network to a homogeneous trajectory of the uncoupled system by a local pinning control strategy. Several sufficient conditions are derived to guarantee the network synchronisation by investigating the relationship among pinning synchronisation, network topology, and coupling strength. Also, some fundamental and yet challenging problems in the pinning control of complex networks are discussed：（1） what nodes should be selected as pinned candidates？（2） How many nodes are needed to be pinned for a fixed coupling strength？ Furthermore, an adaptive pinning control scheme is developed. In order to achieve synchronisation of an uncertain complex network, the adaptive tuning strategy of either the coupling strength or the control gain is utilised. As an illustrative example, a network with the Lorenz system as node self-dynamics is simulated to verify the efficacy of theoretical results.

关键词： uncertain complex network pinning control synchronisation adaptive tuning

A Method for Deploying the Minimal Number of UAV Base Stations in Cellular Networks

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IEEE/CAA Journal of Automatica Sinica 2020年第2期7卷 559-567页

作者： Hailong Huang Chao Huang Dazhong Ma college of information science and engineering Northeastern University

In this paper,we consider the scenario of using unmanned aerial vehicles base stations(UAV-BSs)to serve cellular *** particular,we focus on frnding the minimum number of UAV-BSs as well as their *** propose an optimization model which minimizes the number of UAV-BSs and optimize their positions such that the user equipment(UE)covered ratio is no less than the expectation of network suppliers,the UEs receive acceptable downlink rates,and the UAV-BSs can work in a sustainable *** show the NP-hardness of this problem and then propose a method to address *** method first estimates the range of the number of UAV-BSs and then converts the original problem to one which maximizes the UE served ratio,given the number of UAV-BSs within that *** present a maximizing algorithm to solve it with the proof of *** simulations based on a realistic dataset have been conducted to demonstrate the effectiveness of the proposed method.

关键词： Blanket coverage cellular networks coverage control proactive deployment unmanned aerial vehicles(UAV)

SAR Slow Moving Target Imaging Based on Over-Sampling Smooth Algorithm

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Chinese Journal of Electronics 2017年第4期26卷 876-882页

作者： SHI Hongyin YANG Xiaoyan ZHOU Qiuxiao LIAN Qiusheng college of information science and engineering Yanshan University

A novel Synthetic aperture radar(SAR)signal processing technique has been proposed which refocused slow moving targets based on phase retrieval algorithm. After theoretical derivation, we can get that the raw data Fourier magnitude of slow moving targets is approximate to the stationary ones in the SAR system. By applying the Fourier magnitude of received data to phase retrieval algorithms, the blur and defocusing effect caused by the moving of the targets can be eliminated. The simulated results demonstrate the validity of this algorithm.

关键词： Synthetic aperture radar Slow moving target imaging Phase retrieval Over-sampling smooth

Tight focusing of partially polarized vortex beams by binary phase Fresnel zone plates

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Chinese Physics B 2011年第11期20卷 248-254页

作者：舒建华陈子阳蒲继雄刘永欣 college of information science and engineering Huaqiao University

Based on vectorial Debye theory, the focusing properties of partially polarized vortex beam by high numerical aperture Fresnel zone plate are investigated. The effects of the numerical apertures of and the phase difference of binary phase Fresnel zone plates, the topological charge of vortex beam and the degree of polarization of incident beam on the intensity distribution and degree of coherence in the focal plane are investigated in detail. It is shown that elliptical light spots and the flat top beam can be obtained by selecting certain parameters. Studies of degree of coherence reveal that the degree of coherence between x and y components of the electric field, which is zero in the source plane, is improved in the focal plane for vortex beam, but it is hardly changed for the nonvortex beam. It is also proved that any two of the three electric field components Ex, Ey and Ez are completely coherent everywhere in the focal region if the incident light beam is linearly polarized.

关键词： partially polarized vortex beams high numerical aperture binary phase Fresnel zoneplates

Fault tolerant synchronization of chaotic systems based on T-S fuzzy model with fuzzy sampled-data controller

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Chinese Physics B 2010年第5期19卷 104-114页

作者：马大中张化光王占山冯健 college of information science and engineering Northeastern University

In this paper the fault tolerant synchronization of two chaotic systems based on fuzzy model and sample data is investigated. The problem of fault tolerant synchronization is formulated to study the global asymptotical stability of the error system with the fuzzy sampled-data controller which contains a state feedback controller and a fault compensator. The synchronization can be achieved no matter whether the fault occurs or not. To investigate the stability of the error system and facilitate the design of the fuzzy sampled-data controller, a Takagi Sugeno （T-S） fuzzy model is employed to represent the chaotic system dynamics. To acquire good performance and produce a less conservative analysis result, a new parameter-dependent Lyapunov-Krasovksii functional and a relaxed stabilization technique are considered. The stability conditions based on linear matrix inequality are obtained to achieve the fault tolerant synchronization of the chaotic systems. Finally, a numerical simulation is shown to verify the results.

关键词： fault tolerant synchronization fuzzy sampled-data controller Takagi-Sugeno (T-S) fuzzy model linear matrix inequality (LMI)

Multiple Relay Selection Based on Game Theory in Cooperative Cognitive Radio Networks

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Chinese Journal of Electronics 2017年第3期26卷 624-633页

作者： WU Renyong WANG Wenru LI Renfa The college of information science and engineering Hunan University

Due to the inefficiency of traditional fixed spectrum allocation policies,the paradox of apparent spectrum scarcity occurs while most of the bands are *** has prompted proposals for Dynamic spectrum sharing(DSS),which explains why Cognitive radio network(CRN)has been widely accepted as a promising approach to settle inefficient usage of scarce available radio *** a subset of DSS,Dynamic spectrum leasing(DSL)strategy has been proposed based on game idea,where Primary user(PU)has an incentive to allow Cognitive users(CUs)to access its licensed spectrum for a fraction of time in exchange for *** paper proposes an approach,named multiple relay selection based on Game theory(GTMRS),to optimize the utilities of PU and CUs as a whole,where a pricing-based spectrum leasing mechanism is *** the parameter price c is jointly determined by PU and CUs,all selected cognitive user’s optimal cooperative powers can be satisfied through a non-cooperative game among *** results show that more CUs are involved in the cooperation and both utilities of PU and CUs as a whole are improved,which means the whole system throughput is increased.

关键词： Cognitive radio networks Dynamic spectrum leasing Cooperative transmission Nash equilibrium