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Dynamic decoupling tracking control for the polytopic LPV model of hypersonic vehicle

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Science China(information Sciences) 2015年第9期58卷 181-194页

作者： LAN Xue Jing WANG YongJi LIU Lei national key laboratory of Science and Technology on Multispectral information processing School of Automation Huazhong University of Science and Technology

The dynamic decoupling problem of the hypersonic flight vehicle(HFV) is considered in this *** Linear Parameter-Varying(LPV) model of the HFV is firstly obtained and smoothly transformed into a polytopic form by the Tensor-Product(TP) model transformation method. After that, a dynamic decoupling control method is derived by minimizing the H∞norm of a virtual system, which is composed by the controlled system and the no coupling reference model. The necessary and sufficient condition for the existence of the controller is derived based on Linear Matrix Inequalities(LMIs). Next, the decoupling controller for the polytopic LPV model of HFV is designed. And the simulation results show that the proposed method has perfect performance in terms of dynamic decoupling.

关键词： HFV polytopic LPV model reference model LMIs dynamic decoupling

On book thickness parameterized by the vertex cover number

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Science China(information Sciences) 2022年第4期65卷 112-113页

作者： Yunlong LIU Jie CHEN Jingui HUANG School of information Science and Engineering Hunan Provincial Key Laboratory of Intelligent Computing and Language Information Processing Hunan Normal University

Dear editor,Book thickness for graphs forms a major theme in graph theory and has a broad application in the fields of sorting permutations, fault tolerant VLSI design, parallel computing, and others. The book Thickness problem, even if the vertex order is taken as part of the input, was shown to be NP-complete in general [1, 2]. Just because of this, parameterized algorithms have been proposed to deal with it [3].

关键词： Book Thickness Vertex Cover Number Linear Order 1-page embedding graph kernel

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Lyapunov-based switched-gain impact angle control guidance

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Chinese Journal of Aeronautics 2018年第4期31卷 765-775页

作者： Zhongtao CHENG Lei LIU Yongji WANG national key laboratory of Science and Technology on Multispectral information processing School of AutomationHuazhong University of Science and Technology

To hit stationary ground targets in specified direction, a nonlinear impact angle control guidance law based on Lyapunov stability theory is proposed. The proposed law ensures the convergence of the heading angle and the miss distance to guarantee a successful engagement. The impact angle can be adjusted by varying a single parameter. And the maximum value of acceleration has been analyzed to get the proper range for control parameter. Considering the achievable impact angle set is limited, an additional phase is added to form a two-phase control *** first phase is to establish a proper initial condition for the second phase, and the second phase is to hit the target with a certain impact angle. An analysis of the proper selection of control parameters to expand the achievable impact angle set is presented. The performance of the proposed guidance law is illustrated with simulations.

关键词： Composite Achievable range Guidance Impact angle control Lyapunov stability theory

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Chinese Named Entity Recognition Augmented with Lexicon Memory

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Journal of Computer Science & Technology 2023年第5期38卷 1021-1035页

作者：周奕郑骁庆黄萱菁 School of Computer Science Fudan UniversityShanghai 200438China Shanghai key laboratory of intelligent information processing Shanghai 200438China

Inspired by the concept of content-addressable retrieval from cognitive science,we propose a novel fragment-based Chinese named entity recognition(NER)model augmented with a lexicon-based memory in which both character-level and word-level features are combined to generate better feature representations for possible entity *** that the boundary information of entity names is particularly useful to locate and classify them into pre-defined categories,position-dependent features,such as prefix and suffix,are introduced and taken into account for NER tasks in the form of distributed *** lexicon-based memory is built to help generate such position-dependent features and deal with the problem of out-of-vocabulary *** results show that the proposed model,called LEMON,achieved state-of-the-art performance with an increase in the Fl-score up to 3.2%over the state-of-the-art models on four different widely-used NER datasets.

关键词： named entity recognition(NER) lexicon-based memory content-addressable retrieval position-dependent feature neural network

The sound and complete R-calculus for revising propositional theories

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Science China(information Sciences) 2015年第9期58卷 5-16页

作者： LI Wei SUI YueFei SUN MeiYing State key laboratory of Software Development Environment Beihang University key laboratory of intelligent information processing Institute of Computing TechnologyChinese Academy of Sciences University of Chinese Academy of Sciences

The AGM postulates are for the belief revision(revision by a single belief), and the DP postulates for the iterated revision(revision by a finite sequence of beliefs). Li gave an R-calculus for R-configurations?|Γ,where ? is a set of atomic formulas or the negations of atomic formulas, and Γ is a finite set of formulas. In this paper, two deduction systems for the revision of a theory by another theory are given such that the systems are sound and complete, that is, if ?|Γ■Γ′ is provable then Γ′■ ? is consistent and Γ′- ? is a maximal subset of Γ such that(Γ′- ?) ∪ ? is consistent; and for any finite theories ? and Γ, there is a finite theoryΓ′ such that Γ′- ? is a maximal subset of Γ such that(Γ′- ?) ∪ ? is consistent, and ?|Γ ? Γ′ is ***, if?|Γ■Γ′ is provable then Γ′ satisfies the AGM and the DP postulates.

关键词： belief revision R-calculus minimal change the AGM postulates the DP postulates

Robust variable normalization least mean p-power algorithm

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Science China(information Sciences) 2020年第9期63卷 294-302页

作者： Kui XIONG Yu ZHANG Shiyuan WANG College of Electronic and information Engineering Southwest University Chongqing key laboratory of Nonlinear Circuits and intelligent information processing Faculty of Computer and information Science Southwest University

Dear editor,Adaptive filtering algorithms have been widely applied in system identification, channel equalization, and echo cancellation over the past decades [1–3]. Generally, adaptive filtering algorithms can be ge... 详细信息

关键词： Least mean p-power algorithm variable normalization sigmoid function steady-state performance analysis noise robustness

Hybrid Lifting Wavelet-Like Transform for Solution of Electromagnetic Integral Equation

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Chinese Physics Letters 2008年第3期25卷 1000-1003页

作者：陈明生吴先良沙威黄志祥 key laboratory of intelligent Computing and Signal processing Anhui University Hefei 230039

A hybrid lifting wavelet-like transform scheme is successfully applied to the solution of electric field integral equation using Rao-Wilton-Glisson basis functions. To speed up the matrix transform process, the lifting scheme is adopted. Numerical examples of different three-dimensional perfectly electric conducting objects are considered. Compared with the method of moments, the proposed matrix transform scheme can save considerable CPU time and memory.

关键词： supernova explosion proto-neutron star shock wave

Image retrieval based on color features integrated with anisotropic directionality

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Journal of Systems Engineering and Electronics 2010年第1期21卷 127-133页

作者： Jing Bai Xiaohua Wang Licheng Jiao key laboratory of intelligent Perception and Image Understanding of Ministry of Education of China Institute of Intelligent Information Processing Xidian University Xi'an 710071 P. R. China

A novel image retrieval approach based on color features and anisotropic directional information is proposed for content based image retrieval systems （CBIR）. The color feature is described by the color histogram （CH）, which is translation and rotation invariant. However, the CH does not contain spatial information which is very important for the image retrieval. To overcome this shortcoming, the subband energy of the lifting directionlet transform （L-DT） is proposed to describe the directional information, in which L-DT is characterized by multi-direction and anisotropic basis functions compared with the wavelet transform. A global similarity measure is designed to implement the fusion of both color feature and anisotropic directionality for the retrieval process. The retrieval experiments using a set of COREL images demonstrate that the higher query precision and better visual effect can be achieved.

关键词： image retrieval color histogram directionlet transform anisotropic similarity.

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On the criteria for designing complex orthogonal space-time block codes

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Science China(information Sciences) 2016年第8期59卷 153-163页

作者： Haibin KAN Xiaodong LIU Guangyue HAN School of Computer Science Fudan University Shanghai key laboratory of intelligent information processing Fudan University Department of Mathematics University of Hong Kong

A complex orthogonal design(COD) used in space-time block codes is a kind of combinatorial design. It has been well studied because it has a fast maximum-likelihood decoding algorithm and achieves full diversity. When designing CODs, there are seven characteristics that should be considered, which include code rate, decoding delay, transceiver signal linearization, peak-to-average power ratio, etc. In this paper, we study the relationships among these design criteria. We prove that the maximum rate of generalized CODs(GCODs)that meet the last five criteria is 1/2. Moreover, we present a new method to construct GCODs based on *** this method on balanced complex orthogonal designs(BCODs), we obtain a novel class of GCODs that performs almost perfectly with respect to all the seven properties.

关键词： space-time block code complex orthogonal design decoding delay transceiver signal linearization peak-to-average power ratio(PAPR)