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On the new results of global attractive set and positive invariant set of the Lorenz chaotic system and the applications to chaos control and synchronization

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Science in china(Series F) 2005年第3期48卷 304-321页

作者： LIAO Xiaoxin 1, 2, 3 , FU Yuli 4 & XIE Shengli 4 1. Department of Control Science & Control Engineering, huazhong university of Science & technology, wuhan 430074, china 2. school of Automation, wuhan university of Science & technology, wuhan 430070, china 3. school of Information, Central South university of Economy, Politics and Law, wuhan 430064, china 4. school of Electronics & Information Engineering, South china university of technology, Guangzhou 510640, china Correspondence should be addressed to Liao Xiaoxin (email: xiaoxin_liao@***) 1. Department of Control Science & Control Engineering Huazhong University of Science & Technology 430074 Wuhan China 2. school of Automation Wuhan University of Science & Technology 430070 Wuhan China 3. school of Information Central South University of Economy Politics and Law 430064 Wuhan China 4. school of Electronics & Information Engineering South China University of Technology 510640 Guangzhou China

Constructing a family of generalized Lyapunov functions, a new method is proposed to obtain new global attractive set and positive invariant set of the Lorenz chaotic system. The method we proposed greatly simplifies the complex proofs of the two famous estimations presented by the Russian scholar Leonov. Our uniform formula can derive a series of the new estimations. Employing the idea of intersection in set theory, we extract a new Leonov formula-like estimation from the family of the estimations. With our method and the new estimation, one can confirm that there are no equilibrium, periodic solutions, almost periodic motions, wandering motions or other chaotic attractors outside the global attractive set. The Lorenz butterfly-like singular attractors are located in the global attractive set only. This result is applied to the chaos control and chaos synchronization. Some feedback control laws are obtained to guarantee that all the trajectories of the Lorenz systems track a periodic solution, or globally stabilize an unstable (or locally stable but not globally asymptotically stable) equilibrium. Further, some new global exponential chaos synchronization results are presented. Our new method and the new results are expected to be applied in real secure communication systems.

关键词： Lorenz chaotic system global attractive set positive invariant set globally exponential tracking globally exponential synchronization.

Synthesis of Cr-Al_2O_3 Cermet Selective Surfaces Coated by SnO_2 Thin Film by Air Plasma Spraying

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稀有金属材料与工程 2012年第S1期41卷 272-275页

作者： Zhu Zhenqi,Cheng Xudong,Li Guanglei school of Materials Science and technology,wuhan university of technology,wuhan 430070,china wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Sch Mat Sci & Technol Wuhan 430070 Peoples R China

High efficient Cr-Al2O3 cermet selective surfaces coated by sol-gel SnO2 thin film for high-temperature application were synthesized by air plasma spraying(APS),followed further heat and polish *** phase composition and micro morphology of coating samples were characterized by X-ray diffractions(XRD),scanning electron microscope(SEM)and roughmeter *** solar absorptance(α)and thermal emittance(ε)were determined by optical spectrum *** results show that Cr-Al2O3 cermet coating has a high absorptivity nearly *** unfortunately,the emissivity of these coatings is nearly 0.50 because of the big thickness and coarse surface prepared by APS ***,once coated SnO2 thin film,the composite coatings exhibit excellent selective absorbing property of α=0.89 and ε=***,SnO2 thin film plays a significant role in decreasing the emissivity of coatings as antireflection *** furthermore,the optical performance shows that more metal content and smooth surface are favorable for the selective absorbing ***,the coatings have excellent bond strength with stainless steel substrate and thermal shock resistance at high temperature.

关键词： selective surfaces SnO2 thin film air plasma spraying

A Scheme for Reconstructing Free-form Surface from Shading with Cellular Automata

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武汉理工大学学报 2006年第S2期28卷 517-521页

作者： XU Bin TANG Linxin SHI Hanmin (school of Mechanical Science and Engineering,huazhong university of Science and technology,wuhan 430074 china school of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

The reconstruction of free-form surface is a fundamental problem in digital *** article presents a novel solution to reconstructing free-form surface from an intensity image under the Lambertian reflection model,that is a method called shape from shading (SFS).Our approach is based on the two-dimensional cellular automata (CA),and fully uses the local information of both image and the reconstructed *** several iterations,the free-form surface corresponding to the input image is *** encouraging results on both synthetic and real-world images are provided in this paper,and the perfor- mance of our algorithm is analyzed on synthetic images using mean and standard deviation of depth (Z) errors.

关键词： digital design 3D reconstruction shape from shading cellular automata

Evaluation Method of Web Site Structure Based on Web Structure Mining

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wuhan university Journal of Natural Sciences 2003年第3A期8卷 791-796页

作者： Li Jun\|e 1 , Zhou Dong\|ru 2 1. Computer Center,wuhan university, wuhan 430072, hubei, china 2. school of Computer,wuhan university, wuhan 430072, hubei,china wuhan university Computer Center Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) wuhan university School of Computer Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

The structure of Web site became more complex than before. During the design period of a Web site, the lack of model and method results in improper Web structure, which depend on the designer's experience. From the point of view of software engineering, every period in the software life must be evaluated before starting the next period's work. It is very important and essential to search relevant methods for evaluating Web structure before the site is completed. In this work, after studying the related work about the Web structure mining and analyzing the major structure mining methods (Page\|rank and Hub/Authority), a method based on the Page\|rank for Web structure evaluation in design stage is proposed. A Web structure modeling language WSML is designed, and the implement strategies for evaluating system of the Web site structure are given out. Web structure mining has being used mainly in search engines before. It is the first time to employ the Web structure mining technology to evaluate a Web structure in the design period of a Web site. It contributes to the formalization of the design documents for Web site and the improving of software engineering for large scale Web site, and the evaluating system is a practical tool for Web site construction.

关键词： web structure mining page\|rank web structure evaluation modeling language for web structure

Concrete Physics Method for Solving NP hard Problem

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wuhan university Journal of Natural Sciences 2001年第Z1期6卷 140-146页

作者： Huang Wen\|qi College of Computer Science, huazhong university of Science and technology, wuhan 430074,china Laboratory of Computer Science, Institute of software, Chinese Academy of Sciences, Beijing 100080, china College of Computer Science Huazhong University of Science and Technology Wuhan China Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing China

With a NP hard problem given, we may find a equivalent physical world. The rule of the changing of the physical states is simply the algorithm for solving the original NP hard problem .It is the most natural algorithm for solving NP hard problems. In this paper we deal with a famous example , the well known NP hard problem——Circles Packing. It shows that our algorithm is dramatically very efficient. We are inspired that, the concrete physics algorithm will always be very efficient for NP hard problem.

关键词： concrete physics algorithm NP hard problem circles packing the rule of the changing of the physical states

Early Age Compressive Strength of Pastes by Electrical Resistivity Method and Maturity Method

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Journal of wuhan university of technology(Materials Science) 2011年第5期26卷 983-989页

作者：肖莲珍 school of Materials Science and Engineering Wuhan Institute of Technology

The compressive strength development of Portland cement pastes was investigated by the electrical resistivity method and the maturity *** experiments were carried out on the cement pastes with different water-cement ratios at different curing *** results show that the application of the maturity method has limitation to obtain the *** is found that both of the compressive strength and the electrical resistivity follow hyperbolic trend for all the *** hyperbolic equation of each mix is obtained to estimate the ultimate resistivity value which can probably be *** relationship between electrical resistivity and compressive strength of the cement pastes is established based on the test results and interpreted by the empirical Archie equation and a strength-porosity *** relationship between the electrical resistivity after temperature correction and the compressive strength was linear and independent of curing temperature and water-cement ratio.

关键词： electrical resistivity cement hydration compressive strength maturity method

Some Index Classes of Singularity of Vector Fields on Manifolds with Boundary

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wuhan university Journal of Natural Sciences 2002年第4期7卷 388-390页

作者： Xu Xu, Liu Heng-xing school of Mathematics and Statistics, wuhan university, wuhan 430072, hubei, china wuhan university School of Mathematics and Statistics Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

V. I. Arnold defined some particular classes of index for singularities of adapted fields. We generalize these index classes for general fields on manifolds with boundary and get some relations of these index classes.

关键词： adapted fields singularity index

Estimating the mixing matrix by using less sparsity

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Progress in Natural Science:Materials International 2009年第8期19卷 1027-1031页

作者： Guoxu Zhou a, Zuyuan Yang a, Xiaoxin Liao b, Jinlong Zhanga a school of Electrics & Information Engineering, South china university of technology, Guangzhou 510641, china b Department of Control Science and Engineering, huazhong university of Science and technology, wuhan 430074, china [a]school of Electrics & Information Engineering South China University of Technology Guangzhou 510641 China [b]Department of Control Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

In this paper, the nonlinear projection and column masking (NPCM) algorithm is proposed to estimate the mixing matrix for blind source separation. It preserves the samples which are close to the interested direction while suppressing the rest. Compared with the existing approaches, NPCM works efficiently even if the sources are less sparse (i.e., they are not strictly sparse). Finally, we show that NPCM provides considerably accurate estimation of the mixing matrix by simulations.

关键词： Sparse component analysis Blind source separation Particle swarm optimization

STUDY OF HYDRODYNAMIC FORCES OF SHIPS IN NARROW WATERWAY

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Journal of Hydrodynamics 2003年第4期15卷 113-117页

作者： Zhang Xie-dong, Wu Xiu-heng school of Transportation, wuhan university of technology, wuhan 430063, china school of Transportation Wuhan University of Technology Wuhan 430063 China

The collision of ships in narrow waterway may occur for a variety of *** hydrodynamic forces between two ships change the maneuvering characteristics of ships *** based on the boundary element method, this paper proposes a calculation method for hydrodynamicinteraction forces between ships under meeting and passing conditions in narrow waterway. Theresults from this method are compared with the existing results obtained from other theoreticalapproaches, and they are in good agreement.

关键词： collision of ships narrow waterway hydro-dynamic interaction boundaryelement method