Modelling Aggregation on the Large Scale and Regularity on the Small Scale in Spatial Point Pattern Datasets

We consider a dependent thinning of a regular point process with the aim of obtaining aggregation on the large scale and regularity on the small scale in the resulting target point process of retained points. Various parametric models for the underlying processes are suggested and the properties of the target point process are studied. Simulation and inference procedures are discussed when a realization of the target point process is observed, depending on whether the thinned points are observed or not. The paper extends previous work by Dietrich Stoyan on interrupted point processes.     

CSG理论在计算机辅助设计中的应用

ＣＳＧ理论是构造实体模型的基础，本文以ＡｕｔｏＣＡＤ为例，讨论了基于ＣＳＧ理论的三维造型技术及其在计算机辅助设计及辅助绘图中的应用。     

从两个公式看累积投票制的适用

2006年1月1日开始实施的《公司法》明确规定股份公司在选举董事、监事时可实行累积投票制,原意是更好地维护中小股东的权益,然而从两个简单的公式即可看出累积投票制的实施必然会遇到一些困难。     

Minimum ε-equivalent Circuit Size Problem

For a Boolean function f given by its truth table (of length ) and a parameter s the problem considered is whether there is a Boolean function g -equivalent to f, i.e., , and computed by a circuit of size at most s. In this paper we investigate the complexity of this problem and show that for specific values of it is unlikely to be in P/poly. Under the same assumptions we also consider the optimization variant of the problem and prove its inapproximability.     

可达矩阵的新求法

将模糊数学求传递闭包的思想应用到离散数学中。利用可达矩阵与邻接矩阵的关系,引进模糊矩阵的合成运算,根据可达矩阵的常用求法,推证出新的可达矩阵的计算公式,并提出了逐次平方的算法,该算法简单易行。     

Extended tables of the distribution of friedman’ s s-statistic in the two-way layout

Friedman’s (1937, 1940) S-statistic is designed to test the hypothesis that there is no treatment effect in a randomized-block design with k treatments and n blocks. In this paper we give tables of the null distribution of S for k = 5, n = 6(1)8, and for k = 6, n = 2(1)6. Computational details are discussed.     

Complexity of Some Problems Concerning 2CNF Formulas

In this paper we investigate the complexity of several problems concerning 2CNF formulas. At first, we show that the minimal unsatisfiability problem for 2CNF formulas can be solved in linear time. Then we prove that the problem determining if a 2CNF formula can be transformed to a minimal unsatisfiable formula is also solvable in linear time. Thirdly, we show the polynomial solvability of the satisfiability problem for symmetric monotone formulas in which all clauses has length 2 or ? n - k ( n is the number of variables and k is a fixed positive integer). Finally, we prove that the satisfiability of symmetric monotone formulas in which each literal occurs at most twice depends only on the 2-clauses they contains.     

Modified Asymptotic Formulas for Critical Values of the Kolmogorov Test Statistic

A brief discussion is given of the Kolmogorov test of goodness of fit. Modified asymptotic formulas for critical values of the test statistic, much more accurate for small-to-moderate sample sizes than the usual asymptotic formulas, are given.     

多哈回合关税减让分层公式原理与方案评价

在WTO多哈回合农业谈判中,农产品关税减让模式成为各国关注的热点,各国纷纷提出各自的减让方案。针对多哈回合谈判研究中被忽视的分层减让公式原理和主要参数的设置问题,从统计学的角度分析了分层减让方式的参数设置及性质、特征,对多哈回合农产品主要谈判方如美国、欧盟、G20所提出的减让方案进行评价和比较。结论表明：从关税结构而言,层数越少,分组越粗,则减让力度相对平均;反之层数越多,分组越细,则减让力度相对集中。对于各方提案,在分组宽度不同条件下,需要进一步讨论减让幅度。在同样分组宽度条件下,低幅减让会使新税率相对较大,与原税率差距较小,反之亦然。     

可达性矩阵的C语言程序实现

讨论了可达性矩阵的数学思想以及用计算机程序实现其复杂的求解过程。