含高阶余项的非线性动力系统数值计算法

建立了一种求解非线性动力系统高精度数值计算的新方法,重构了等价的非线性动力系统方程,该方程考虑了非线性函数的任意高阶项,并给出了该方程的Duhamel积分表达式,在时间步长内用Newton-Raphson法进行数值迭代求解,该方法能连续满足微分方程而不只是在离散的步长端点满足方程,从而打破了传统的Euler型有限差分法。计算实例表明,该方法计算精度高于传统的Runge-Kutta,Newmark-β和Wilson-θ等方法。     

基于身份的动态数字签名方案

数字签名是解决信息安全问题的重要途径,用于鉴别用户身份.随着计算机、网络的发展,安全的用户数字签名显得尤为重要.目前,现代的数字签名技术正向智能化、密码化、多因素、大容量和快速响应方向发展.结合数论中的中国剩余定理及RSA公钥体制,提出了一种基于身份的动态数字签名方案.     

Replenishment routing problems between a single supplier and multiple retailers with direct delivery

We consider the replenishment routing problems of one supplier who can replenish only one of multiple retailers per period, while different retailers need different periodical replenishment. For simple cases satisfying certain conditions, we obtain the simple routing by which the supplier can replenish each retailer periodically so that shortage will not occur. For complicated cases, using number theory, especially the Chinese remainder theorem, we present an algorithm to calculate a feasible routing so that the supplier can replenish the selected retailers on the selected periods without shortages.     

Greatest remainder bi-proportional rounding and the Greek parliamentary elections of 2007

Matrix scaling is the problem of assigning values to the elements of a matrix that are proportional to a given input matrix. The assignment should fulfill a set of row- and column-sum requirements. We propose a new method that differs from divisor-type methods appeared until now in the literature. This method combines the largest remainder apportionment and bi-proportional rounding. Exhaustive application to the Greek parliamentary elections of 2007 justify our effort.     

确定代数方程根位置的快速无除算法

本文提供了一个确定整系数代数方程在指定区域内根的个数的快速无除算法,此算法的复杂性为O(n²),其中n为方程的次数.为了强凋算法的稳定性,本文均用精确的整数运算.其中多项式是无平方的、首一的.     

板几何中具反射边界条件的迁移算子的谱

在LP(1p<∞)空间研究了板几何中一类带反射边界条件具各向异性、连续能量、均匀介质迁移算子的谱,证明了该迁移算子生成C0半群的Dyson-Phillips展开式的二阶余项在LP(1相似文献   

有理插值的一种递推算法

针对给定的数据型值点,利用多项式带余除法,给出有理函数插值的一种新型递推算法,可以求出满足插值条件的所有有理插值函数,并举例说明其有效性.     

The remainder term in asymptotic summation of linear difference systems

Quantitative estimates for the remainder terms in the asymptotic summation of linear difference systems are derived. For example, it is shown that any decay in excess of summability is passed on to the remainder.     

What are the last digits of …?

We propose a class assignment where students are asked to construct and implement an efficient algorithm to calculate the last digits of a positive integral power of a positive integer. The mathematical prerequisites for this assignment are very limited: knowledge of remainder calculus and the binary representation of a positive integer. The periodicity of the last digits is studied by means of the Euler totient function and the Carmichael function.     

Finding strong pseudoprimes to several bases

Define to be the smallest strong pseudoprime to all the first prime bases. If we know the exact value of , we will have, for integers , a deterministic primality testing algorithm which is not only easier to implement but also faster than either the Jacobi sum test or the elliptic curve test. Thanks to Pomerance et al. and Jaeschke, are known for . Upper bounds for were given by Jaeschke.

In this paper we tabulate all strong pseudoprimes (spsp's) to the first ten prime bases which have the form with odd primes and There are in total 44 such numbers, six of which are also spsp(31), and three numbers are spsp's to both bases 31 and 37. As a result the upper bounds for and are lowered from 28- and 29-decimal-digit numbers to 22-decimal-digit numbers, and a 24-decimal-digit upper bound for is obtained. The main tools used in our methods are the biquadratic residue characters and cubic residue characters. We propose necessary conditions for to be a strong pseudoprime to one or to several prime bases. Comparisons of effectiveness with both Jaeschke's and Arnault's methods are given.