一种随机聚类法(Ⅱ)

本文给出了一般情况下评价校验码算法的准则 .这个准则可以用于判定校验码算法的优劣并指导校验码算法的设计     

随机序与寿命分布类

各种各样的随机序是随机比较的最基本的概念，每一种新的，有实际背景和理论依据的随机序的引入会丰富随机比较方法的研究内容，也有可能使人们更好洞察和理解其中某些概念和结果的本质。而反映时效性质的寿命分布类的研究不仅是随机比较方法的重要组成部分，而且它在运籍学，应用概率和统计学中有广泛的应用。各种寿命分布类的定义密切密切联系于各种不同的随机序，而且人们还可以反过来从寿命分布类出发定义新的随机序，由此又能引     

命题公式集F(S)的基于R0-算子的16类分划

利用R0-蕴涵算子对命题公式集F(S)进行分类,得出了F(S)的—个16类分划,并证明了这种分类关于非运算是同余分类.最后讨论了各类关于MP运算与HS运算的封闭性.     

球面闭曲线和Jacobi定理

回答了W.Fenchel所提出的一个问题.给出球面闭曲线的一个整体性质,并用以推广关于空间闭曲线的Jacobi定理.     

层次结构中封闭子图的映射

在[3]中,我们就层次结构(BS)中,任意一个封闭子图G_(5)∈G_(5)真的扩展,建立了其边界映射的三原则,并在这些原则的基础上,构造了该映射的表达式。本文,进一步按映射三原则扩展这一映射表达式,并使之一般化。最后,我们还建立了封闭子图G_(5)映射定理,说明了如果映射存在则G_(5)的映射像ε(G_(5))就可以构造而得。     

命题公式集F(S)的基于R0-算子的16类分划

利用R₀-蕴涵算子对命题公式集F(S)进行分类,得出了F(S)的一个16类分划,并证明了这种分类关于非运算是同余分类.最后讨论了各类关于MP运算与HS运算的封闭性.     

对裁判的裁判——主观评分中裁判水平的评价

在主观评分项目的比赛中，裁判的评分不仅是对参赛者的裁判，而且是裁判自身裁判水平的表现．传统的统计方法没有完整地讨论过对裁判的评价问题．本文对主观评分项目比赛（如体操、跳水、歌咏、舞蹈、酒茶等等）中裁判员的表现进行数量分析加工，提炼出对裁判员评价的数量指标，期望产生得到社会公认的对裁判员评价的数量方法，使主观评分更加客观公正．     

六元gcd封闭集上Smith矩阵的整除性

我们给出了关于六元gcd封闭集S的充分必要条件,使得在整数矩阵环M_6(Z)中,定义在S上的e次幂GCD矩阵(S~e)整除e次幂LCM矩阵[S~e].这部分解决了Hong在2002年提出的一个公开问题.     

圆锥曲线的平行弦中点的轨迹

<正>我们从大家所熟悉的圆的平行弦中点的轨迹开始研究.例1已知圆x~2+y~2=r~2,B为该圆内的■动弦.斜率为m(常数).求此动弦中点轨迹的方程.分析涉及圆内弦的中点,同学自然想到垂径定理:垂直于弦的直径平分弦.     

有限群作用下等变自映射的C1封闭引理

证明了有限群作用下等变自映射的一个C¹ 封闭引理 ,结果表明对这样的一个等变自映射 ,它的一个非游荡轨道及与其对称的轨道可以在一个C¹ 小等变扰动下成为封闭的周期轨道 .     

Forecasting transport requirements for district primary health care in Ghana: A simulation study

In rural planning in developing countries, random factors such as vehicle breakdown, weather conditions and staff availability are particularly important. These can be dealt with specially well by simulation. Transportation is also particularly important in rural areas. This paper presents a simulation study of transport requirements for a rural primary health care scheme in Ghana where the random factors are unavailability of vehicles due to repairs and unavailability of health specialists and drivers for work due to holidays, etc. The analysis gives a quick method of calculating the expected number of jobs that can be done for given numbers of vehicles, levels of availability etc. The simulation gives the corresponding probability distribution. The analysis also indicates which random factor has most effect on limiting the number of jobs that can be done. Policy conclusions are drawn regarding the number of vehicles per district and the payment of incentives to staff for good attendance.     

Finding a Cluster of Zeros of Univariate Polynomials

A method to compute an accurate approximation for a zero cluster of a complex univariate polynomial is presented. The theoretical background on which this method is based deals with homotopy, Newton's method, and Rouché's theorem. First the homotopy method provides a point close to the zero cluster. Next the analysis of the behaviour of the Newton method in the neighbourhood of a zero cluster gives the number of zeros in this cluster. In this case, it is sufficient to know three points of the Newton sequence in order to generate an open disk susceptible to contain all the zeros of the cluster. Finally, an inclusion test based on a punctual version of the Rouché theorem validates the previous step. A specific implementation of this algorithm is given. Numerical experiments illustrate how this method works and some figures are displayed.     

On properties of random dissections and triangulations

In this work we study properties of random graphs that are drawn uniformly at random from the class consisting of biconnected outerplanar graphs, or equivalently dissections of large convex polygons. We obtain very sharp concentration results for the number of vertices of any given degree, and for the number of induced copies of a given fixed graph. Our method gives similar results for random graphs from the class of triangulations of convex polygons.     

Some Global Theorems on Closed Surfaces With Qenus Zero in E~3

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基于失效分析的独立均匀随机变量和的分布及应用初探

数学模型是基于材料失效分析提出来的,同时结合了BS模型的方法理论背景.材料样品在周期性应力作用下,主因裂纹的扩大量是一个随机变量.对于均匀材料,主因裂纹的扩大量可看作是均匀随机变量与一个大于零的实数的乘积,材料主因裂纹的总的扩大量可表示为这些独立均匀随机变量的和,或称为加权随机和.实际上,本文给出一类新的随机模型及其概率分布函数,并初步讨论了该模型分布的一些基本特征,通过数值模拟还讨论了其独特的分布特征,如与正态分布的关系与区别,以及该模型分布收敛于正态分布的速度等.这些工作可为材料失效分析提供新的模型与方法.     

Random and Exhaustive Generation of Permutations and Cycles

In 1986 Sattolo introduced a simple algorithm for uniform random generation of cyclic permutations on a fixed number of symbols. This algorithm is very similar to the standard method for generating a random permutation, but is less well known. We consider both methods in a unified way, and discuss their relation with exhaustive generation methods. We analyse several random variables associated with the algorithms and find their grand probability generating functions, which gives easy access to moments and limit laws.      

Ranking and unranking planar embeddings

In this paper, we give a formula for computing the number of different planat embeddings of any planar biconnected graph. The enumeration method used in deriving the formula readily gives rise to efficient algorithms for the ranking, unranking and random generation of embeddings of the given graph. We also give linear time algorithms for checking planarity and constructing any particular embedding.     

Z[(1 21~(1/2))/2]上正定幺模格的分类(英文)

本文综合利用邻格方法及Siegelmass公式对Z[(1 2 1) /2 ]上秩 4的正定幺模格实现了分类 ,得到了gen(I4 )的类数为 9,偶模格的类数为 3,并且给了代表格     

Two Badly Behaved Percolation Processes on a Nonunimodular Graph

We provide nonunimodular counterexamples to two properties that are well known for automorphism invariant percolation on unimodular transitive graphs. The first property is that the number of encounter points in an infinite cluster is almost surely 0 or ∞. The second property is that speed of random walk on an infinite cluster is almost surely well defined.