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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 {2. of Aeronautics and Astronautics, Beijing 100191, china 2.department of computer science and engineering, Henan Institute of engineering, Zhengzhou 451191, china School of Aeronautic science and engineering Beijing University of Aeronautics and Astronautics Beijing China department of computer {2. and engineering Henan Institute of Engineering Zhengzhou 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

The integration of methanogenesis with denitrification and anaerobic ammonium oxidation in an expanded granular sludge bed reactor

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Journal of Environmental sciences 2003年第3期15卷 423-432页

作者： ZHANG Dai-jun 1,2.(1. department of Environmental science, Chongqing {2., Campus A, Chongqing 400044, china 2. Key Laboratory for the Southwest china Resources Exploitation and Environmental Disaster Control engineering, Ministry of Education, china.) department of Environmental science Chongqing University Campus A 重庆 400044

The integration of methanogenesis with denitrification and anaerobic ammonium oxidation(ANAMMOX) was studied in an expanded granular sludge bed(EGSB) reactor in this work. Experimental results from the continuous treatment of wastewater with nitrite and ammonium, which lasted for 107 days, demonstrated that wastewater with high nitrite and ammonium could be anaerobically treated in an expanded granular sludge bed reactor. More than 91% to 97% of COD were removed at up to about 3.9 g COD/(L·d) of COD volumetric loading rate. More than 97% to 100% of nitrite was denitrified at up to about 0.8 g NO -_2.N/(L·d), which is 16 times higher than that in a conventional activated sludge system with nitrification/denitrification(0.05 gN/(L·d)). No dissimilatory reduction of nitrite to ammonium occurred in the process. However, maximum of about 40% ammonium was found to be lost. Batch tests of 15 days with sludge from the reactor showed that 100% of nitrite was denitrified completely, and about 3% of ammonium was removed when only ammonium (34.3 mg/L) and nitrite(34.3 mg/L) were added into the sludge suspension medium. Furthermore, about 15% of ammonium amounts were lost with organic COD addition. It suggested that the methanogenesis in the system could enhance ANAMMOX because of intermediate hydrogen produced during methanogenesis.

关键词： methanogenesis denitrification ANAMMOX EGSB reactor

Characterizations of α-Bloch functions on the unit ball without use of derivative

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science china Mathematics 2008年第11期51卷 1965-1981页

作者： CHEN HuaiHui School of Mathematics and computer science, {2. Normal university, {2. 2.0097, china School of Mathematics and computer science Nanjing Normal University Nanjing China

In this paper we establish characterizations of α-Bloch functions on the unit ball without use of derivative, which are stronger, more precise and general than those obtained by Nowak and Zhao.

关键词： α-Bloch function unit ball Bergman metric 32.18 32.37

Uniform blow-up profiles and boundary layer for a parabolic system with localized nonlinear reaction terms

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science china Mathematics 2005年第2期48卷 185-197页

作者： LI Huiling & WANG Mingxin department of Mathematics, southeast university, {2. 2.0018, china department of Mathematics, Xuzhou Normal university, Xuzhou 2.1116, china department of Mathematics Southeast University Nanjing China department of Mathematics Xuzhou Normal University Xuzhou China

This paper deals with the blow-up properties of the solution to a semilinear parabolic system with localized nonlinear reaction terms, subject to the null Dirichlet boundary condition. We first give sufficient conditions for that the classical solution blows up in the finite time, secondly give necessary conditions and a sufficient condition for that two components blow up simultaneously, and then obtain the uniform blow-up profiles in the interior. Finally we describe the asymptotic behavior of the blow-up solution in the boundary layer.

关键词： parabolic system, localized nonlinear reaction terms, blow-up profiles, boundary layer size.

Seamlet carving for shape-aware image resizing

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science china(Information sciences) 2012年第5期55卷 1073-1081页

作者： LIN Xiao 1,2.SHENG Bin 1,MA LiZhuang 1,SHEN Yang 1 & CHEN ZhiHua 3 1 department of computer {2. and engineering,Shanghai Jiao Tong university,Shanghai 2.02.0,china 2.Academy of Information Technology,Luoyang Normal university,Luoyang 47102.,china 3 department of computer {2. and engineering,East{12. university of {2. and Technology,Shanghai 2.02.7,china department of computer {2. and engineering Shanghai Jiao Tong University Shanghai China Academy of Information Technology Luoyang Normal University Luoyang China department of computer {2. and engineering East China University of Science and Technology Shanghai China

In this paper we propose an optimized seam-carving approach for anti-shearing image *** image/video seam-carving strategy only focuses on deleting the pixels along 8-connected seams,which may lead to the obvious information loss during *** the traditional seam-carving methods,our approach can construct a seamlet to handle the discontinuous pixels and further achieve an optimized image resizing results with *** particular,to suppress zigzag artifacts,we introduce the anti-shearing energy into the seamlet generation,which includes two steps:1) the energy map is formalized by using Gabor filtering and the saliency map;2. The energy computation is optimized in Gabor feature space to obtain the resizing results without the connectivity *** experimental results and comparisons show the effectiveness of our method.

关键词： image resizing seamlet carving saliency map

Reducing component estimation for varying coefficient models with longitudinal data

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science china Mathematics 2008年第2期51卷 250-272页

作者： TANG QingGuo~(1,2.) WANG JinDe~2.1 Institute of sciences,People’s Liberation Army university of science and Technology,nanjing 2.0007,china 2.department of Mathematics,nanjing university,nanjing 2.0093,china Institute of sciences People’s Liberation Army University of Science and Technology Nanjing China department of Mathematics Nanjing University Nanjing China

Varying-coefficient models with longitudinal observations are very useful in epidemiology and some other practical *** this paper,a reducing component procedure is proposed for es- timating the unknown functions and their derivatives in very general models,in which the unknown coefficient functions admit different or the same degrees of smoothness and the covariates can be time- *** asymptotic properties of the estimators,such as consistency,rate of convergence and asymptotic distribution,are *** asymptotic results show that the asymptotic variance of the reducing component estimators is smaller than that of the existing estimators when the coefficient functions admit different degrees of *** sample properties of our procedures are studied through Monte Carlo simulations.

关键词： varying coefficient model longitudinal data nonparametric estimation reducing component estimators asymptotic normality 62.07

Mechanical behavior of a shelter system based on cable-strut structures

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Journal of Zhejiang university-science A(Applied Physics & {2.) 2012年第12期13卷 895-903页

作者： Jian-guo CAI1,2.Ya ZHOU1,Jian FENG1,2.Yi-xiang XU3 (1Key Laboratory of C&PC Structures of Ministry of Education,southeast university,{2. 2.0096,china) (2.ational Prestress engineering Research Center,southeast university,{2. 2.0096,china) (3department of Civil engineering,Strathclyde university,Glasgow,UK) Key Laboratory of C&PC Structures of Ministry of Education Southeast University Nanjing China National Prestress engineering Research Center Southeast University Nanjing China department of Civil engineering Strathclyde University Glasgow UK

A shelter system based on cable-strut structures,consisting of compressive struts and high-tensile elements,is described in this *** deployment of the shelter is achieved by tightening inclined *** cables are used to terminate the *** state of self-stress of the cable-strut structures in the fully deployed configuration is given,and the minimum strut length and the maximum load design of the shelter are *** mechanical behavior of the system was studied under symmetrical and asymmetrical load *** results show that the shelter in the deployed configuration satisfies the ultimate limit and the serviceability limit state ***,the stability of the cable-strut system is investigated,considering the effect of imperfections on the buckling of the *** conclude that the influence of imperfections based on the consistent imperfection mode method is not significant.

关键词： Foldable structures Cable-strut structures Mechanical behavior Self-stress Stability

Controlled free radical polymerization of styrene initiated from the alkoxyamine-functionalized silicon surface

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science china Chemistry 2005年第5期48卷 449-458页

作者： CHEN Zhijun1, ZHOU Sikai1, LU Wenzhong1, FANG Shaoming1, JIANG Xiqun2.& YANG Changzheng2.1. College of Materials and Chemical engineering, Zhengzhou university of Light Industry, Zhengzhou 450002.{2. 2. Laboratory of Mesoscopic Material science and department of Polymer science & engineering, College of Chemistry & Chemical engineering, nanjing university, nanjing 2.0093,{2. College of Materials and Chemical engineering Zhengzhou University of Light Industry Zhengzhou China Laboratory of Mesoscopic Material science and department of Polymer science & engineering College of Chemistry & Chemical Engineering Nanjing University Nanjing China

We describe a new method of fabricating a brush-like polystyrene layer anchored on the surface of the silicon substrate, which involves three steps, namely (i) the attachment of 3-methacryloxypropyltrimethoxysilane onto the silicon surface; (ii) the reaction of vinyl moiety at another extremity of the anchored 3-methacryloxypropyltrimethoxysilane to 4-Hydroxyl-2. 2. 6, 6-tetramethyl-1-piperidinyloxy (HTEMPO?) catalyzed by azobisisobutyronitrile (AIBN); (iii) living free radical grafting polymerization of styrene in the presence of HTEMPO?. The controllable living free radical polymerization permits accurate control of both the molecular weight and the polydispersity. X-photoelectron spectroscopy measurement proved that the alkoxyamine initiator layer forms on the silicon surface. XPS and Ellipsometry measurements showed that the poly-styrene chains were covalently anchored onto the silicon surface. The thickness of the grafted polymer layer can be accurately manipulated by altering the polymerization time. The new method allows synthesizing random copolymer and block copolymers by the sequential growth of monomers from the substrate surface.

关键词： polymer brush, controlled living free radical polymerization, thickness, atomic force microscopy, 3-methacryloxypropyltrimethoxysilane.

Image stylization with enhanced structure on GPU

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science china(Information sciences) 2012年第5期55卷 1093-1105页

作者： LI Ping 1,SUN HanQiu 1,SHENG Bin 1,2.& SHEN JianBing 3 1 department of computer {2. and engineering,The Chinese university of Hong Kong,Hong Kong,china 2.department of computer {2. and engineering,Shanghai Jiao Tong university,Shanghai 2.02.0,china 3 School of computer {2. and Technology,Beijing Institute of Technology,Beijing 100081,china department of computer {2. and engineering The Chinese University of Hong Kong Hong Kong China department of computer {2. and engineering Shanghai Jiao Tong University Shanghai China School of computer science and Technology Beijing Institute of Technology Beijing China

This paper presents a graphics processing unit (GPU) based stylization approach that preserves the fine structure between the original and the stylized images using gradient *** abstraction and painterly stylization methods focused on contrast manipulation only,and thus the detailed salient structures of the input images are always destroyed when performing the current stylization techniques because of limitations like unavoidable salience information loss caused by contrast *** propose an image structure map to naturally model the fine structure existing in the original ***-based structure tangent generation and tangent-guided image morphology are used to construct the structure *** image structure map,unlike an edge map,not only systematically models the boundary information within the imagery but also accentuates the underlying inner structure detail for further *** facilitate the final stylization via parallel bilateral grid and structure-aware stylizing optimization on a GPU-CUDA platform in real *** multiple experiments,the proposed method consistently demonstrates efficient and high quality image stylization performance.

关键词： image stylization non-photorealistic rendering real-time processing GPU image abstraction