基于单模数线性同余方程组设计的公钥密码体系

本文基于MH-KPKC体系和HILL密码体系的构建思想,提出了基于单模数线性同余方程组设计的公钥密码体系.该体制无需利用超递增序列和贪心算法恢复明文.算例说明了该体制的可行性。     

单模数多变量二次同余方程组的求解及其在信息安全中的应用

根据二次同余理论,利用当P=5mod8,n^（p-1）/4=±1modp时,方程X^2=nmodP的解有具体表达式这一事实,设计了基于多变量二次同余方程组实现的密码体系。数值算例证明,该类密码体系是可行的,体系信息冗余且是一次一密的,要依赖于解密策略的交互确认,所以该类密码体系是安全的。     

多元多项式环上模的中国剩余定理

中国剩余定理在数论及代数中起着重要的作用.在多元多项式环中,中国剩余定理可以转化为多元多项式同余方程组的求解,借助代数理论,可以找到满足同余方程组的多项式.本文研究多元多项式环上关于模的中国剩余定理,并利用模的Gr?bner基理论与方法找出满足模的中国剩余定理的多项式向量,从而找到多项式环上模的同余方程组的解.     

纯正半群上若干同余的刻划(英文)

本文在纯正半群上首先引入了关系ρｍｉｎ,ρｍａｘ,ρｍｉｎ和ρｍａｘ,刻划了纯正半群上一般同余的迹类。然后利用核－迹方法给出了纯正半群上几类特殊同余的等价刻划。在此基础上,进一步研究了各类同余间的相互联系,把逆半群上有关同余的若干结果推广到纯正半群上。     

半环上的素同余和同余的根

主要研究了可换幂等元半环的同余.给出了素同余和同余的根的一些结果,且揭示了同余ρ的根与包含ρ的素同余的全体之间的关系.     

一类同余方程解数的上界估计

主要研究形如 rⅡi=1(X+m_i)≡2rⅡj=r+1(X+m_j)(mod p~μ)的同余方程关于m=(m_1,…,m_(2r))解数估计问题,并得出当r=4,5时,该同余方程解数的上界估计.前者可改进Dodd的结论,而后者则町应用于对另一类同余方程组解数的上界估计.     

关于广义Stirling数偶的同余性

本文证明了广义Ｓｔｉｒｌｉｎｇ数偶的一些同余性质，从而回答了文［５］中的一个猜测．这些结果做为特例推广了已知的关于两类Ｓｔｉｒｌｉｎｇ数的同余性质．     

求解中国剩余定理的矩阵变换方法

将问题所对应的一次同余方程组等价地转化为整系数线性方程组问题,借用欧氏环上的线性方程组理论,提出矩阵变换的新算法.通过三个不同的算例,演示了算法的可行性,并分析其优劣性.同时还指出,该方法有效地搭建起《高等代数》与《近世代数》的教学衔接桥梁,有助于诱导学生发现问题和提升解决问题的能力.     

纯正半群上的同余扩张(一)

刻划半群上的同余及其扩张是半群的代数理论中的一个非常重要的课题．本文讨论了带上的同余的正规性和不变性以及在其Ｈａｌｌ半群上的扩张，从同余扩张的角度刻划了带上的同余的性质，给出了扩张的极大、极小同余的描述．     

完全正则半群上的H-相关同余

本文研究了完全正则半群上的H-相关同余.给出了完全正则半群上的H-相关同余的概念以及若干等价刻画.     

Determining a Rotation of a Tetrahedron from a Projection

The following problem, arising from medical imaging, is addressed: Suppose that T is a known tetrahedron in ?³ with centroid at the origin. Also known is the orthogonal projection U of the vertices of the image ?T of T under an unknown rotation ? about the origin. Under what circumstances can ? be determined from T and U?     

Calculating a function of a matrix with a real spectrum

Let T be a square matrix with a real spectrum, and let f be an analytic function. The problem of the approximate calculation of f(T) is discussed. Applying the Schur triangular decomposition and the reordering, one can assume that T is triangular and its diagonal entries t_ii are arranged in increasing order. To avoid calculations using the differences t_ii ? t_jj with close (including equal) t_ii and t_jj, it is proposed to represent T in a block form and calculate the two main block diagonals using interpolating polynomials. The rest of the f(T) entries can be calculated using the Parlett recurrence algorithm. It is also proposed to perform some scalar operations (such as the building of interpolating polynomials) with an enlarged number of significant decimal digits.

     

On a mapping of a projective space into a sphere

We obtain an exact estimate for the minimum multiplicity of a continuous finite-to-one mapping of a projective space into a sphere for all dimensions. For finite-to-one mappings of a projective space into a Euclidean space, we obtain an exact estimate for this multiplicity for n = 2, 3. For n ≥ 4, we prove that this estimate does not exceed 4. Several open questions are formulated.     

Evolution to a steady state for a rarefied gas flowing from a tank into a vacuum through a plane channel

A kinetic equation (S-model) is used to solve the nonstationary problem of a monatomic rarefied gas flowing from a tank of infinite capacity into a vacuum through a long plane channel. Initially, the gas is at rest and is separated from the vacuum by a barrier. The temperature of the channel walls is kept constant. The flow is found to evolve to a steady state. The time required for reaching a steady state is examined depending on the channel length and the degree of gas rarefaction. The kinetic equation is solved numerically by applying a conservative explicit finite-difference scheme that is firstorder accurate in time and second-order accurate in space. An approximate law is proposed for the asymptotic behavior of the solution at long times when the evolution to a steady state becomes a diffusion process.     

Motion of a container as a nonholonomous system in a curved section of a horizontal pipeline

The problem of the motion of a container in a curved section of a horizontal pipeline is solved using second-order Lagrange equations in the presence of nonholonous couplings. The special case of the motion of a container in a circular curve is examined.Translated from Matematicheskie Metody i Fiziko-Mekhanicheskie Polya, No. 25, pp. 90–95, 1987.