针对单混沌系统可能会出现的动力学特性退化的缺陷,基于多混沌系统和开关技术,提出开关控制混沌伪随机比特发生器(Switch Controller Chaos&Pseudo Random Bit Generator,简称SCS-PRBG).通过对SCS-PRBG密钥流及其性能的理论分析,表...针对单混沌系统可能会出现的动力学特性退化的缺陷,基于多混沌系统和开关技术,提出开关控制混沌伪随机比特发生器(Switch Controller Chaos&Pseudo Random Bit Generator,简称SCS-PRBG).通过对SCS-PRBG密钥流及其性能的理论分析,表明该数字流密码具有较好的随机性与安全性,并且在硬件并行计算的环境下可以极大地提高加密速度.实验研究表明本加密算法具有较高的安全性.展开更多
A simple wave is defined as a flow in a region whose image is a curve in the phase space. It is well known that "the theory of simple waves is fundamental in building up the solutions of flow problems out of elementa...A simple wave is defined as a flow in a region whose image is a curve in the phase space. It is well known that "the theory of simple waves is fundamental in building up the solutions of flow problems out of elementary flow patterns" see Courant and Friedrichs's chassical book "Supersonic Flow and Shock Waves". This paper mainly concerned with the geometric construction of simple waves for the 2D pseudo-steady compressible Euler system. Based on the geometric interpretation, the expansion or compression simple wave flow construction around a pseudo-stream line with a bend part are constructed. It is a building block that appears in the global solution to four contact discontinuities Riemann problems.展开更多
文摘针对单混沌系统可能会出现的动力学特性退化的缺陷,基于多混沌系统和开关技术,提出开关控制混沌伪随机比特发生器(Switch Controller Chaos&Pseudo Random Bit Generator,简称SCS-PRBG).通过对SCS-PRBG密钥流及其性能的理论分析,表明该数字流密码具有较好的随机性与安全性,并且在硬件并行计算的环境下可以极大地提高加密速度.实验研究表明本加密算法具有较高的安全性.
基金supported by the National Natural Science Foundation of China (No.0971130)the Shanghai Leading Academic Discipline Project (No.J50101)
文摘A simple wave is defined as a flow in a region whose image is a curve in the phase space. It is well known that "the theory of simple waves is fundamental in building up the solutions of flow problems out of elementary flow patterns" see Courant and Friedrichs's chassical book "Supersonic Flow and Shock Waves". This paper mainly concerned with the geometric construction of simple waves for the 2D pseudo-steady compressible Euler system. Based on the geometric interpretation, the expansion or compression simple wave flow construction around a pseudo-stream line with a bend part are constructed. It is a building block that appears in the global solution to four contact discontinuities Riemann problems.