Table of Content

    25 January 2007, Volume 46 Issue 1
    Discussion and Improvement on Empirical Mode Decomposition Algorithm                                                                                                
    2007, 46(1):  1-6. 
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    The stopping criteria for sifting and boundary effect are studied for Empirical Mode Decomposition(EMD) algorithm.The decomposition is enhanced by combining with the alternative EMD approach and the new stopping criteria.The alternative EMD approach circumvents the problem of boundary continuation in B-Spline interpolation,where the signal is assumed to be infinitely long.A discussion for boundary continuation with finite length is presented and its algorithm is developed.This research compensates for the existing approach and can serve as an applicable method in practice.Experiments show that the proposed method is effective.

    Construct and Estimate the Random Model about the Longtitudinal Data Under Competing Risks
    2007, 46(1):  7-10. 
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     In order to study the multivariate survival data,a unique random variable is applied to multiply each competing hazard to reveal the relation of different causes,and COX Proportional Hazard model is assumed for each competing hazard.This looks more difficult of estimating intensively in traditional view,but it is more coincident with the actual facts.Using hierarchical likelihood approach,the multidimensional integral is avoided,and the hierarchical likelihood function and the process of estimating model are derived.

    Multilevel Iteration Fast Algorithm for the Parabolic Equations 
    2007, 46(1):  11-15. 
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    A multievel iteration fast algorithm is presented for solving parabolic equations.The multiscale orthogonal wavelet bases in H10(0,1) spaces are choosen and used to dsicretize the parabolic equations.A multilevel iteration scheme is constructed.The numerical example indicates the effectiveness of the algorithm. 

    A Hierarchical Identity-Based Cryptosystem
    2007, 46(1):  16-20. 
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    A new hierarchical identity based(ID-based) cryptosystem is proposed,including hierarchical ID-based encryption and signature.In random oracle model,both hierarchical ID-based encryption and signature schemes are provably secure.Furthermore,the new hierarchical ID-based encryption scheme is secure under selective-ID attack in standard model.Furthermore,the notion of hierarchical proxy decryption is first proposed.Meanwhile,the security model and a generic construction method for proxy decryption are also presented.

    Variational Principles for Nonlinear Elastostatics of Orthogonal Cable-Net Struc
    2007, 46(1):  21-25. 
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    In a simple and unified new way proposed by Luo,some variational principles for geometrically nonlinear elastostatics of orthogonal cable-net structures based on discrete model are established systematically.An important integral relation is given,which can be considered as the generalized principle of virtual work for geometrically nonlinear statics of orthogonal cable-net structures in mechanics.Based on this relation,it is possible not only to obtain the principle of virtual work for geometrically nonlinear statics of orthogonal cable-net structures,but also to derive systematically the complementary functionals for three-field,two-field variational principles and principles of stationary total potential energy and stationary total complementary energy for geometrically nonlinear elastostatics of orthogonal cable-net structures by the generalized Legendre transformations given in this paper.Furthermore,with this approach,the intrinsic relationship among the various principles is explained clearly.