Pure position permutation image encryption algorithms, commonly used as image encryption investigated in this work are unfortunately frail under known-text attack. In view of the weakness of pure position permutation ...Pure position permutation image encryption algorithms, commonly used as image encryption investigated in this work are unfortunately frail under known-text attack. In view of the weakness of pure position permutation algorithm,we put forward an effective decryption algorithm for all pure-position permutation algorithms. First, a summary of the pure position permutation image encryption algorithms is given by introducing the concept of ergodic matrices. Then, by using probability theory and algebraic principles, the decryption probability of pure-position permutation algorithms is verified theoretically; and then, by defining the operation system of fuzzy ergodic matrices, we improve a specific decryption al-gorithm. Finally, some simulation results are shown.展开更多
This paper investigates the maximum principle for viscosity solutions of fully nonlinear, second order parabolic, possibly degenerate partial differential equations. Using this maximum principle the anthor prove that ...This paper investigates the maximum principle for viscosity solutions of fully nonlinear, second order parabolic, possibly degenerate partial differential equations. Using this maximum principle the anthor prove that viscosity solutions of initial and bo unoary value problem for parabolic equations are unique.展开更多
This paper is devoted to the investigation of C^(1,α) regularity of viscosity solutions for aclass of fully nonlinear partial differential equations. The Dirichlet problem of elliptic equa-tions and the first boundar...This paper is devoted to the investigation of C^(1,α) regularity of viscosity solutions for aclass of fully nonlinear partial differential equations. The Dirichlet problem of elliptic equa-tions and the first boundary value problem of parabolic equations are treated in this paper.展开更多
The importance of L inverse process is emphasized and an algorithm is given to realize PO0L inverse process. On the basis of algorithm analysis, this note discusses the possibility of apply-ing L inverse process to da...The importance of L inverse process is emphasized and an algorithm is given to realize PO0L inverse process. On the basis of algorithm analysis, this note discusses the possibility of apply-ing L inverse process to data compression and the difficulties in doing that.展开更多
We give conditions on the function f so that the Cauchy problem to the fast diffusionequations with max has or no global solutions. Asa special case we recover the results to the case f(u) and prove that, if f(u) is ...We give conditions on the function f so that the Cauchy problem to the fast diffusionequations with max has or no global solutions. Asa special case we recover the results to the case f(u) and prove that, if f(u) is convex,on a neighborhood of u=o with logm denoting the logarithm iterated m times, and f satisfies acertain growth condition at infinity, the global solutions exist if q>1.展开更多
基金Project supported by the National Natural Science Foundationof China (Nos. 60302012+2 种基金 60202002) and the Youth ScientificResearch Foundation of Ningbo (No. 2003A61006) China
文摘Pure position permutation image encryption algorithms, commonly used as image encryption investigated in this work are unfortunately frail under known-text attack. In view of the weakness of pure position permutation algorithm,we put forward an effective decryption algorithm for all pure-position permutation algorithms. First, a summary of the pure position permutation image encryption algorithms is given by introducing the concept of ergodic matrices. Then, by using probability theory and algebraic principles, the decryption probability of pure-position permutation algorithms is verified theoretically; and then, by defining the operation system of fuzzy ergodic matrices, we improve a specific decryption al-gorithm. Finally, some simulation results are shown.
基金This work is supported by the National Natural Science Foundation of China
文摘This paper investigates the maximum principle for viscosity solutions of fully nonlinear, second order parabolic, possibly degenerate partial differential equations. Using this maximum principle the anthor prove that viscosity solutions of initial and bo unoary value problem for parabolic equations are unique.
基金Project supported by the National Natural Science Foundation of China.
文摘This paper is devoted to the investigation of C^(1,α) regularity of viscosity solutions for aclass of fully nonlinear partial differential equations. The Dirichlet problem of elliptic equa-tions and the first boundary value problem of parabolic equations are treated in this paper.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 69972045) .
文摘The importance of L inverse process is emphasized and an algorithm is given to realize PO0L inverse process. On the basis of algorithm analysis, this note discusses the possibility of apply-ing L inverse process to data compression and the difficulties in doing that.
文摘We give conditions on the function f so that the Cauchy problem to the fast diffusionequations with max has or no global solutions. Asa special case we recover the results to the case f(u) and prove that, if f(u) is convex,on a neighborhood of u=o with logm denoting the logarithm iterated m times, and f satisfies acertain growth condition at infinity, the global solutions exist if q>1.
