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science China(information sciences) 2011年第12期54卷 2622-2634页

作者： QIAO LiHong 1 , NIU KaiFu 2 , wang Ning 2 & PENG LiZhong 2 1 College of information science and engineering, henan university of technology, zhengzhou 450001, China 2 school of Mathematical sciences, Peking university, Beijing 100871, China 1. College of information science and engineering Henan University of Technology Zhengzhou 450001 China2. School of Mathematical Sciences Peking University Beijing 100871 China

Image modulation represents image by meaningful characters such as image instantaneous amplitude and instantaneous frequency. A perfect reconstruction image modulation method is proposed. In detail, the bidimensional empirical mode decomposition (BEMD) is first improved to adaptively decompose image into monocomponents. Then by the quaternionic analytic method, suitable analytic signals is acquired. A new polar form is further proposed to modulate images, then seven characters are derived including instantaneous amplitude and instantaneous frequencies. We demonstrate the techniques on both synthetic and natural images, depict the needle program of the estimated frequencies and obtain the reconstructions that are the same with the original images. The applications in image segmentation and separation establish the validity of characterizing images of this type as sums of locally narrow band modulated components.

关键词： perfect reconstruction image modulation AM-FM representation BEMD quaternionic analytic signals

Formation control for networked spacecraft in deep space:with or without communication delays and with switching topology

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science China(information sciences) 2011年第3期54卷 469-481页

作者： wang Nan 1,2, ZHANG TianWu 2 & XU JieQiong 1 1 school of Aeronautic science and engineering, Beijing university of Aeronautics and Astronautics, Beijing 100191, China 2 Department of Computer science and engineering, henan Institute of engineering, zhengzhou 451191, China 1. school of Aeronautic science and engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China2. Department of Computer Science and Engineering Henan Institute of Engineering Zhengzhou 451191 China

In this paper, several formation controllers are developed with constant and variable connected communication topology for six-degree-of-freedom (6-DOF) networked spacecraft flying in deep space with constant and time-varying communication delays considered. In the control algorithm, any explicit leader does not exist in the formation team and it is required that each spacecraft communicate only with its neighbors and therefore the required communication loads of the whole formation is greatly reduced. The proposed control strategies allow that each spacecraft can track its desired position and attitude and simultaneously the whole group moves to the desired formation and obtain its desired relative attitudes with its neighbors. Simulation results demonstrate the effectiveness of the proposed controllers.

关键词： deep space graph theory formation control communication topology delays

Using LPP and SFL for Document Query Optimization

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Using LPP and SFL for Document Query Optimization

Document Categorization Algorithm Based on Kernel NPE

2009中国控制与决策会议

作者： ziqiang wang,Qingzhou Zhang,Xia Sun school of information science and engineering,henan university of technology,zhengzhou 450001,China

＜正＞To efficiently cope with document query optimization problem,an efficient document query optimization algorithm based on locality preserving projection（LPP） and shuffled frog leaping（SFL） algorithm is presented in this *** document discriminant features are first extracted by the LPP algorithm,then the SFL algorithm is used to retrieval relevant documents based on the extracted *** experimental results show that the proposed algorithm achieves much better performance than other conventional document query optimization algorithms.

关键词： Query optimization Locality preserving projection(LPP) Shuffled frog leaping(SFL) algorithm

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Document Categorization Algorithm Based on Kernel NPE

A New Secure Password Authentication Scheme Using Smart Cards

2009中国控制与决策会议

作者： ziqiang wang,Xia Sun,Qingzhou Zhang school of information science and engineering,henan university of technology,zhengzhou 450001,China

＜正＞To efficiently tackle document classification problem,a novel document classification algorithm based on kernel neighborhood preserving embedding（KNPE） is proposed in this *** discriminant features are first extracted by the KNPE algorithm,then SVM is used to classify the documents into semantically different classes. Experimental results on real document databases have demonstrated the better performance of the proposed algorithm.

关键词： Document classification Kernel method Neighborhood preserving embedding Data mining

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Wuhan university Journal of Natural sciences 2008年第6期13卷 739-743页

作者： wang Bangju1,2, wang Yuhua3, ZHANG Huanguo1 1. school of Computer, Wuhan university/Key Laboratory of Aerospace information Security and Trust Computing of Ministry of Education, Wuhan 430072, Hubei, China 2. school of science, Huazhong Agricultural university, Wuhan 430070, Hubei, China 3. College of information science and engineering, henan university of technology zhengzhou 450001, henan, China school of information science and technology Southwest Jiaotong University Chengdu 610031 Sichuan China

Thirteen security requirements for an ideal password authentication scheme using smart cards are listed and a new smart card based password authentication scheme with identity anonymity is proposed. The new scheme can satisfy all the listed ideal security requirements and has the following merits：（1） it can resist all the attacks listed in introduction; （2） less storage memory requirement due to no verification table stored in server; （3） low computational cost due to hash functions based operations; （4） even if the smart card is lost, the new system is still secure; （5） As user identity is anonymous, this scheme is more practical. The new proposed scheme can be applied in source constraint networks.

关键词： password password authentication hash function attack smart card

Full-domain collaborative deployment method of multiple interference sources and evaluation of its deployment effect

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Defence technology（防务技术） 2024年第2期32卷 572-595页

作者： Yue wang Fuping Sun Xian wang Jinming Hao Kai Xiao school of Geospatial information The PLA Information Engineering UniversityZhengzhou 450001HenanChina

This paper realizes the full-domain collaborative deployment of multiple interference sources of the global satellite navigation system(GNSS)and evaluates the deployment effect to enhance the ability to disturb the attacker and the capability to defend the GNSS during navigation *** evaluation indicators for the jamming effect of GNSS suppressive and deceptive jamming sources are first created,their evaluation models are built,and their detection procedures are sorted out,as the basis for determining the deployment *** principles for collaboratively deploying multi-jamming sources are developed to obtain the deployment structures(including the required number,structures in demand,and corresponding positions)of three single interference sources required by collaboratively ***,simulation and hardware-in-loop testing results are presented to determine a rational configuration of the collaborative deployment of multi-jamming sources in the set situation and further realize the full-domain deployment of an interference network from ground,air to *** evaluation indices for the deployment effect are finally developed to evaluate the deployment effect of the proposed configuration and further verify its reliability and rationality.

关键词： Jamming effect Multiple interference sources Collaborative deployment Effect evaluation Defense capability

Small-signal Stability Constrained Optimal Power Flow Considering Eigenvalue Distribution

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1052-1062页

作者： Zheng Huang Kewen wang Yi wang Jing Han Jun Liang the school of Electrical and information engineering Zhengzhou UniversityZhengzhou 450001China Cardiff university Cardiff CF243AAU.K.

In the existing small-signal stability constrained op-timal power flow(SSSC-OPF)algorithms,only the rightmost ei-genvalue or eigenvalues that do not satisfy a given threshold,e.g.,damping ratio threshold and real-part threshold of eigen-value,are considered in the small-signal stability *** effect of steady-state,i.e.,operating point,changes on eigen-values is not fully taken into *** this paper,the small-signal stability constraint that can fully reflect the eigenvalue change and system dynamic performance requirement is formed by analyzing the eigenvalue distribution on the complex *** small-signal stability constraint is embedded into the standard optimal power flow model for generation *** simultaneous solution formula of the SSSC-OPF is es-tablished and solved by the quasi-Newton approach,while pen-alty factors corresponding to the eigenvalue constraints are de-termined by the stabilization degree of constrained *** improve the computation speed,a hybrid algorithm for ei-genvalue computation in the optimization process is proposed,which includes variable selection for eigenvalue estimation and strategy selection for eigenvalue *** effectiveness of the proposed algorithm is tested and validated on the New England 10-machine 39-bus system and a modified practical 68-machine 2395-bus system.

关键词： Damping ratio eigenvalue optimal power flow quasi-Newton approach sensitivity small-signal stability

Tuning microstructures of TC4 ELI to improve explosion resistance

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Defence technology（防务技术） 2024年第3期33卷 78-99页

作者： Changle Zhang Yangwei wang Lin wang Zixuan Ning Guoju Li Dongping Chen Zhi-Wei Yan Yuchen Song Xucai wang school of Materials science and engineering Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of science and technology on Materials under Shock and Impact Beijing 100081China State Key Laboratory of Explosive science and technology Beijing Institute of TechnologyBeijing 100081China Aerospace information Research Institute Chinese Academy of SciencesBeijing 100094China school of Aeronautical engineering Zhengzhou University of AeronauticsHenan ProvinceZhengzhou 450046China Shanxi Jiangyang Chemical Co. Ltd.Shanxi ProvinceTaiyuan 030041China Shandong Institute of Non-metallic Materials Shandong ProvinceJinan 250031China

A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion ***,there is limited investigation on tuning microstructures of TC4 ELI to improve explosion ***,the current challenge is quantifying microstructural changes'effects on explosion resistance and incorporating microstructural changes into finite element *** work aims to tune microstructures to improve explosion resistance and elucidate their anti-explosion mechanism,and find a suitable method to incorporate microstructural changes into finite element *** this work,we systematically study the deformation and failure characteristics of TC4 ELI plates with varying microstructures using an air explosion test and LS-DYNA finite element *** Johnson-Cook(JC)constitutive parameters are used to quantify the effects of microstructural changes on explosion resistance and incorporate microstructural changes into finite element *** of the heat treatment,one plate has equiaxed microstructure and the other has bimodal *** convex of the plate after the explosion has a quadratic relationship with the charge mass,and the simulation results demonstrate high reliability,with the error less than 17.5%.Therefore,it is feasible to obtain corresponding JC constitutive parameters based on the differences in microstructures and mechanical properties and characterize the effects of microstructural changes on explosion *** bimodal target exhibits excellent deformation *** response of bimodal microstructure to the shock wave may be more intense under explosive *** well-coordinated structure of the bimodal target enhances its resistance to deformation.

关键词： Microstructure Finite element modelling Parameter optimization Failure characteristics Explosion resistance

Resilient Smart Power Grid Synchronization Estimation Method for System Resilience with Partial Missing Measurements

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1307-1319页

作者： Yi wang Yanxin Liu Mingdong wang Venkata Dinavahi Jun Liang Yonghui Sun school of Electrical and information engineering Zhengzhou UniversityZhengzhou 450001China henan engineering Research Center of Power Electronics and Energy Systems Zhengzhou 450001China Department of Electrical and Computer engineering University of AlbertaEdmontonAB T6G 2V4Canada school of engineering Cardiff UniversityCardiff CF243AAUK College of Energy and Electrical engineering Hohai UniversityNanjing 210098China IEEE

With the increasing demand for power system stability and resilience,effective real-time tracking plays a crucial role in smart grid ***,most studies have focused on measurement noise,while they seldom think about the problem of measurement data loss in smart power grid *** solve this problem,a resilient fault-tolerant extended Kalman filter(RFTEKF)is proposed to track voltage amplitude,voltage phase angle and frequency ***,a threephase unbalanced network’s positive sequence fast estimation model is ***,the loss phenomenon of measurements occurs randomly,and the randomness of data loss’s randomness is defined by discrete interval distribution[0,1].Subsequently,a resilient fault-tolerant extended Kalman filter based on the real-time estimation framework is designed using the timestamp technique to acquire partial data loss ***,extensive simulation results manifest the proposed RFTEKF can synchronize the smart grid more effectively than the traditional extended Kalman filter(EKF).

关键词： Dynamic state estimation Kalman filter partial missing measurements power systems smart grid synchronized measurements