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A new trust region algorithm for image restoration

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science china Mathematics 2005年第2期48卷 169-184页

作者： WEN Zaiwen & WANG Yanfei State Key Laboratory of Scientific Engineering Computing, institute of Computational Mathematics and Scientific/Engineering Computing, academy of Mathematics and System sciences, chinese academy of sciences, beijing 100080, china National Key Laboratory on Remote Sensing science, institute of Remote Sensing Applications, chinese academy of sciences, beijing 100101, china State Key Laboratory of Scientific Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing China National Key Laboratory on Remote Sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing China

The image restoration problems play an important role in remote sensing and astronomical image analysis. One common method for the recovery of a true image from corrupted or blurred image is the least squares error (LSE) method. But the LSE method is unstable in practical applications. A popular way to overcome instability is the Tikhonov regularization. However, difficulties will encounter when adjusting the so-called regularization parameter a. Moreover, how to truncate the iteration at appropriate steps is also challenging. In this paper we use the trust region method to deal with the image restoration problem, meanwhile, the trust region subproblem is solved by the truncated Lanczos method and the preconditioned truncated Lanczos method. We also develop a fast algorithm for evaluating the Kronecker matrix-vector product when the matrix is banded. The trust region method is very stable and robust, and it has the nice property of updating the trust region automatically. This releases us from tedious finding the regularization parameters and truncation levels. Some numerical tests on remotely sensed images are given to show that the trust region method is promising.

关键词： trust region algorithm, image restoration, Lanczos method, Kronecker matrix-vector product, preconditioning.

A fiducial argument for generalized p-value

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science china Mathematics 2007年第7期50卷 957-966页

作者： Xin-min LI~(1+) Xing-zhong XU~2 Guo-ying LI~3 1 institute of Applied Mathematics,Shandong University of Technology,Zibo 255049,china 2 Department of Mathematics,beijing institute of Technology,beijing 100801,china 3 academy of Mathematics and systems science,chinese academy of sciences,beijing 100800,china institute of Applied Mathematics Shandong University of Technology Zibo China Department of Mathematics Beijing Institute of Technology Beijing China academy of Mathemtics and systems science Chinese Academy of Sciences Beijing China

This paper provides a general method for constructing generalized p-value via the fiducial ***,the power properties of the generalized test are *** illustrations, the two-parameter exponential distribution and unbalan... 详细信息

关键词： fiducial distribution generalized p-value frequency property two-parameter exponential distribution variance component 62F03 62E15

Synthesis,characterization,and thermostability of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)copper(Ⅱ)

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Rare Metals 2012年第4期31卷 343-349页

作者： ZHANG Teng,GU Hongwei,DING Fazhu,QU Fei,and DAI Shaotao Key Laboratory of Applied Superconductivity,institute of Electrical Engineering,chinese academy of sciences,beijing 100190,china Key Laboratory of Applied Superconductivity Institute of Electrical Engineering Chinese Academy of Sciences Beijing China

Owing to the adaptability to large scale processing,excellent composition control and film uniformity,the metal-organic chemical vapor deposition（MOCVD） technique is a promising process for high-temperature superconductor YBa;Cu;O;（YBCO） *** this technique,the evaporation characteristics and thermostability of adopted precursors in whole process will decide the quality and reproducible results of YBCO *** the present report,bis（2,2,6,6-tetramethyl-3,5-heptanedionato）copper（II）(Cu（TMHD）;) was synthesized by the interaction of copper acetate hydrate with TMHD in methanol solution,and its structure was identified by FTIR,1 H NMR,and EI-MS ***,thermal property and the kinetics of decomposition were systematically investigated by nonisothermal thermogravimetric analysis methods（TGA） at different heating rates in streams of N;,and the average apparent activation energy of evaporation process was evaluated by the Ozawa,Kissinger,and Friedman *** possible conversion function was estimated through the Coats-Redfern method to characterize the evaporation patterns and followed a phase boundary reaction mechanism by the contracting area equation with average activation energy of 85.1 kJ·mol;.

关键词： Cu(TMHD)_2 metal-organic chemical vapor deposition(MOCVD) synthesis thermostability

A two-round honest-verifier zero-knowledge protocol

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science china(Information sciences) 2010年第5期53卷 954-963页

作者： LIU HanWu 1,2 & LIN DongDai 1 1 The State Key Laboratory of Information Security, institute of Software, chinese academy of sciences, beijing 100190, china 2 Graduate University of the chinese academy of sciences, beijing 100049, china The State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing China Graduate University of the chinese academy of sciences Beijing China

Since the concept of zero-knowledge protocols was introduced, it has attracted a lot of attention and in turn showed significant effect on the development of cryptography, complexity theory and other areas. The round complexity of a zero-knowledge protocol is a very important efficiency consideration, and it is required to be as small as possible. Generally, it is desirable to have zero-knowledge protocols with constant numbers of rounds. Goldreich and Oren proved that only languages in BPP have one-round and two-round zero-knowledge protocols. Moreover, they also showed that only languages in BPP have one-round honest-verifier zero-knowledge protocols. The notion of honest-verifier zero-knowledge protocols is highly non-trivial and fascinating itself, and has many other uses. Thus, the problem as to whether there exist two-round honest-verifier zero-knowledge protocols becomes an important open problem. In this paper, we introduce a new simulation technique and present a two-round honest-verifier zero-knowledge protocol for any language in N P under a standard complexity assumption based on this technique.

关键词： proof system argument system zero-knowledge witness indistinguishability black-box one-way permutation commitment scheme zap

Affine bracket algebra theory and algorithms and their applications in mechanical theorem proving

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science china Mathematics 2007年第7期50卷 941-950页

作者： Ning ZHANG~(1+) Hong-bo LI~2 1 china institute for Actuarial science (CIAS),Central University of Finance and Economics,beijing 100081,china 2 academy of Mathematics and systems science,chinese academy sciences,beijing 100080,china china institute for Actuarial science (CIAS) Central University of Finance and Economics Beijing China academy of Mathematics and systems science Chinese Academy Sciences Beijing China

This paper discusses two problems:one is some important theories and algorithms of affine bracket algebra;the other is about their applications in mechanical theorem *** we give some efficient algorithms including the boundary expanding algorithm which is a key feature in *** analyze the characteristics of the boundary operator and this is the base for the implementation of the *** also give some new theories or methods about the exact division,the representations and structure of affine geometry and so *** practice,we implement the mechanical auto-proving system in Maple 10 based on the above algorithms and *** we test about more than 100 examples and compare the results with the methods before.

关键词： mechanical theorem proving geometric invariance bracket algebra affine geometry affine bracket algebra 68T15 03B35

Modeling diameter distribution of the broadleaved-Korean pine mixed forest on Changbai Mountains of china

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science china(Technological sciences) 2006年第Z1期49卷 177-188页

作者： WANG Shunzhong, DAI Limin, LIU Guohua, YUAN Jianqiong, ZHANG Hengmin & WANG Qingli institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china Graduate University of chinese academy of sciences, beijing 100039, china State Key Lab of systems Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, china institute of Applied Ecology Chinese Academy of Sciences Shenyang China Graduate University of chinese academy of sciences Beijing China State Key Lab of systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing China

The broadleaved-Korean pine mixed forest is a native vegetation in the Changbai Mountains, northeast china. The probability density functions including the normal, negative exponential, Weibull and finite mixture distribution, were used to describe the diameter distributions of the species groups and entire forest stand. There is a strong correlation between parameters and mean DBH except the shape parameters in the mixture distribution. The diameter classes of species and entire forest stand showed not negative exponential but normal and "S" distribution. The mixture function was better than normal and Weibull to describe the model distribution. The location parameter had an effect on the estimated frequency in the first diameter class, when the estimated location parameter was bigger than the lower limit of the first diameter class.

关键词： broadleaved-Korean pine mixed forest, diameter distribution, finite mixture distribution.

Absolute Stability of General Lurie Control systems with Multi-Nonlinear Feedback Terms

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Acta Mathematica Sinica,English Series 2001年第4期17卷 649-656页

作者： Zuo Xin GAN Wei Gao GE institute of systems science, chinese academy of sciences, beijing 100080, P. R. china Department of Applied Mathematics, beijing institute of Technology, beijing 100081, P. R. china institute of systems science Chinese Academy of Sciences Beijing 100080 P. R. China Department of Applied Mathematics Beijing Institute of Technology Beijing 100081 P. R. China

In this paper, the problenl of absohlte stability for general Lurie control systems with multi- nonlinear feedback terms is investigated. From the Lyapunov function approach. new necessary and sufficient conditious and some practical sufficient conditions of absolute stability are derived. which improve the absolute stability for the set. A numerical examplc illustrates the effectiveness of the proposed results.

关键词： General Lurie system Multi-nonlinear feedback Absolute stability

Fast Fourier-Galerkin methods for first-kind logarithmic-kernel integral equations on open arcs

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science china Mathematics 2010年第1期53卷 1-22页

作者： WANG Bo1,WANG Rui2 & XU YueSheng3,4,1academy of Mathematics and systems science,chinese academy of sciences,beijing 100190,china 2School of Information science and Engineering,Graduate University of the chinese academy of sciences,beijing 100190,china 3Department of Mathematics,Syracuse University,Syracuse,NY 13244,USA 4Department of Scientific Computing and Computer Applications,Sun Yat-sen University,Guangzhou 510275,china academy of Mathematics and systems science Chinese Academy of Sciences Beijing China School of Information science and Engineering Graduate University of the Chinese Academy of Sciences Beijing China Department of Mathematics Syracuse University Syracuse USA Department of Scientific Computing and Computer Applications Sun Yat-sen University Guangzhou China

We propose a fully discrete fast Fourier-Galerkin method for solving an integral equation of the first kind with a logarithmic kernel on a smooth open arc,which is a reformulation of the Dirichlet problem of the Laplace equation in the *** optimal convergence order and quasi-linear complexity order of the proposed method are established.A precondition is *** this method with an efficient numerical integration algorithm for computing the single-layer potential defined on an open arc,we obtain the solution of the Dirichlet problem on a smooth open arc in the *** examples are presented to confirm the theoretical estimates and to demonstrate the efficiency and accuracy of the proposed method.

关键词： Dirichlet problem open arc singular boundary integral equations Fourier-Galerkin methods logarithmic potentials

CMQV+:An authenticated key exchange protocol from CMQV

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science china(Information sciences) 2012年第7期55卷 1666-1674页

作者： LI Hui 1,2 & WU ChuanKun 1 1 State Key Laboratory of Information Security,institute of Software,chinese academy of sciences,beijing 100190,china 2 Graduate University of chinese academy of sciences,beijing 100049,china State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

Ustaoglu presents a secure and efficient key exchange protocol named CMQV,based on the design rationales of HMQV and *** with the latter two protocols,on one hand,CMQV achieves high performance of HMQV,and on the other,it is proven secure in eCK model as NAXOS ***,CMQV enjoys the security proof under gap Diffie-Hellman assumption as indicated by its *** this paper,we propose a variant of CMQV,called CMQV+,which is proven secure under a weaker assumption (*** Diffie-Hellman assumption) in eCK model with random oracles while maintaining the high-performance feature of CMQV as much as possible.

关键词： key exchange eCK model trapdoor-test technique provable security CDH assumption