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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 science and engineering,shanghai Jiao Tong university,shanghai 2.02.0,china 2 Academy of Information Technology,Luoyang Normal university,Luoyang 471022,china 3 department of computer science and engineering,East china university of science and Technology,shanghai 200237,china 1. department of computer science and engineering Shanghai Jiao Tong University Shanghai 200240 China2. Academy of Information Technology Luoyang Normal University Luoyang 471022 China3. Department of Computer Science and Engineering East China University of Science and Technology Shanghai 200237 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

Identity based signature scheme based on cubic residues

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science china(Information sciences) 2011年第10期54卷 2001-2012页

作者： XING DongSheng,CAO ZhenFu & DONG XiaoLei department of computer science and engineering,shanghai Jiao Tong university,shanghai 2.02.0,china 1. department of computer science and engineering Shanghai Jiao Tong University Shanghai 200240 China

We propose a novel method to compute a cubic root of a cubic residue in Eisenstein *** applying our method,a new identity based signature scheme is proposed based on cubic *** formally prove that our scheme is secure against existential forgery on the adaptive chosen message and identity attacks assuming the hardness of *** scheme is the first identity based signature scheme based on cubic residues.

关键词： Eisenstein ring identity based signature cubic residue factoring random oracle proven security

SEM in-situ Fracture Observation and the Reinforcing Effect of Composite SiC_p/ZA22

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Journal of Materials science & Technology 2001年第6期17卷 649-652页

作者： Jun WANG, Baode SUN and Yaohe ZHOU School of Materials science and engineering, shanghai jiaotong university, shanghai 200030, china Lining ZHANG and Feng CHEN department of Materials science and engineering, Southeast university, shanghai Jiao Tong Univ Sch Mat Sci & Engn Shanghai 200030 Peoples R China SE Univ Dept Mat Sci & Engn Nanjing 210096 Peoples R China

The strengthening effect of a Zn alloy reinforced by SiC particulate was examined. Based on the results of SEM in-situ fracture observation and stress field analysis by finite element method, it is believed that the r... 详细信息

关键词： SiC SEM in-situ Fracture Observation and the Reinforcing Effect of Composite SiC_p/ZA22

Optimal motion planning of an underactuated spacecraft using wavelet approximate method

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Progress in Natural science:Materials International 2006年第8期16卷 868-873页

作者： GE Xinsheng, CHEN Liqun and LIU Yanzhu (Beijing Institute of Machinery, Beijing 100085, china department of Mechanics, shanghai university, shanghai 200072, china department of engineering Mechanics, shanghai jiaotong university, shanghai 200030, china) [a]Beijing Institute of Machiner Beijing China [b]department of Mechanics Shanghai University Shanghai China [c]department of engineering Mechanics Shanghai Jiaotong University Shanghai China

An optimal motion planning scheme using wavelet approximation is proposed for an underactuated spacecraft. The motion planning of an underactuated spacecraft can be formulated as an optimal control of a drift-free system. A cost functional is used to incorporate the control energy and the final state errors. The motion planning is to determine control inputs to minimize the cost functional. Using the method of wavelet, one can transform an infinite-dimensional optimal control problem to a finite-dimensional one and use Gauss-Newton algorithm to solve it for a feasible trajectory which satisfies nonholonomic constraints. The proposed scheme has been applied to a rigid spacecraft with two momentum wheels. The numerical simulation results indicate that optimal control with wavelet approximation is an effective approach to steering an underactuated spacecraft system from the initial configuration to the final configuration.

关键词： underactuated spacecraft motion planning optimal control nonholonomic constraint wavelet analysis.

THE ROBUST CONTROL SCHEME FOR FREE-FLOATING SPACE MANIPULATOR TO TRACK THE DESIRED TRAJECTORY IN JOINTSPACE

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Acta Mechanica Solida Sinica 2001年第2期14卷 183-188页

作者： Chen Li (department of Mechanical engineering, Fuzhou university, Fuzhou 350002, china) Liu Yanzhu (department of engineering Mechanics,shanghai jiaotong university, shanghai 200030, china) ***

The control of a free-floating space manipulator system isdiscussed. With the augmentation approach, the nonlinearparameterization problem of the dynamic equations of the spacemanipulator system is overcome. Based on the results, the robustcontrol scheme for free-floating space manipulator with uncer- tainpayload parameters to track the desired trajectory in jointspace isproposed, and the global convergence of the tracking is verified byusing the Lyapunov method.

关键词： free-floating space maniulator augmentation approach robust control

SURFACE MESH PARAMETERIZATION WITH NATURAL BOUNDARY

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Chinese Journal of Mechanical engineering 2003年第3期16卷 264-267页

作者： Ye MingZhu XiaofengWang ChengtaoSchool of Mechanical engineering,shanghai jiaotong university,shanghai 200030, china School of Mechanical engineering Shanghai Jiaotong University 上海 200030

Using the projected curve of surface mesh boundary as parameter domainborder, linear mapping parameterization with natural boundary is realized. A fast algorithm forleast squares fitting plane of vertices in the mesh boundary is proposed. After the mesh boundary isprojected onto the fitting plane, low-pass filtering is adopted to eliminate crossovers, sharpcorners and cavities in the projected curve and convert it into an eligible convex parameter domainboundary. In order to facilitate quantitative evaluations of parameterization schemes, threedistortion-measuring formulae are presented.

关键词： Parameterization Convex combination mapping Harmonic mapping Dirichletenergy

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 science and engineering,The Chinese university of Hong Kong,Hong Kong,china 2 department of computer science and engineering,shanghai Jiao Tong university,shanghai 2.02.0,china 3 School of computer science and Technology,Beijing Institute of Technology,Beijing 100081,china 1. department of computer science and engineering The Chinese University of Hong Kong Hong Kong China2. Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China3. School of Computer Science and Technology Beijing Institute of Technology Beijing 100081 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

Blake-Wilson,Johnson & Menezes protocol revisited

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science china(Information sciences) 2011年第7期54卷 1365-1374页

作者： HUANG Hai 1,2 & CAO ZhenFu 1 1 department of computer science and engineering,shanghai jiaotong university,shanghai 2.02.0,china 2 Division of computer,Zhejiang Sci-Tech university,Xiasha Higher Education Zone,Hangzhou 310018,china 1. department of computer science and engineering Shanghai Jiaotong University Shanghai 200240 China2. Division of Computer Zhejiang Sci-Tech University Xiasha Higher Education Zone Hangzhou 310018 China

In this paper,we investigate the famous Blake-Wilson,Johnson & Menezes (BJM) authenticated key exchange *** observe that the BJM model fails to model the adversary’s capability in the public setting *** modify the BJM model by providing it with a new Register query and a modified Corrupt *** way,we bring the BJM model further to ***,our modification has a significant impact on the security proof of the BJM ***,the security proofs using CDH assumption will no longer work in the modified BJM *** some modifications,we show that the BJM protocols are secure in the modified BJM model under the gap Diffie-Hellman assumption (GDH).

关键词： authenticated key exchange provable security BJM model gap Diffie-Hellman

An interpolating boundary element-free method (IBEFM) for elasticity problems

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science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 758-766页

作者： REN HongPing 1 , CHENG YuMin 2 & ZHANG Wu 1 1 School of computer engineering and science, shanghai university, shanghai 200072, china 2 shanghai Institute of Applied Mathematics and Mechanics, shanghai university, shanghai 200072, china 1. School of computer engineering and science Shanghai University Shanghai 200072 China2. Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

The paper begins by discussing the interpolating moving least-squares (IMLS) method. Then the formulae of the IMLS method obtained by Lancaster are revised. On the basis of the boundary element-free method (BEFM), combining the boundary integral equation method with the IMLS method improved in this paper, the interpolating boundary element-free method (IBEFM) for two-dimensional elasticity problems is presented, and the corresponding formulae of the IBEFM for two-dimensional elasticity problems are obtained. In the IMLS method in this paper, the shape function satisfies the property of Kronecker δ function, and then in the IBEFM the boundary conditions can be applied directly and easily. The IBEFM is a direct meshless boundary integral equation method in which the basic unknown quantity is the real solution to the nodal variables. Thus it gives a greater computational precision. Numerical examples are presented to demonstrate the method.

关键词： moving least-squares (MLS) approximation interpolating moving least-squares (IMLS) method boundary integral equation meshless method boundary element-free method (BEFM) interpolating boundary element-free method (IBEFM) elasticity problem