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本文主要讨论组合地图列举问题.刘的一部专著中提出了一个判定两个地图是否同构的算法.该算法的时间复杂度为O(m2),其中m为下图的规模.在此基础上,本文给出一个用于地图列举以及进而计算任意连通下图的地图亏格分布的通用算法.本文所得结果比之前文献中所给结果更优. 相似文献
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一、专题的背景与分析
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闵行区的沪闵路─春申路口是交通特别拥挤的交叉路口之一.家住莘庄地区的同学有一个共同的感受,在他们到校或回家路上必经的沪闵路─春申路口时常遇到塞车现象.…… 相似文献
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"牛吃草"问题又称为消长问题,是17世纪英国伟大的科学家牛顿提出来的.典型牛吃草问题的条件是假设草的生长速度固定不变,不同头数的牛吃光同一片草地所需的天数各不相同,求若干头牛吃这片草地可以吃多少天.由于吃的天数不同,草又是天天在生长的,所以草的存量随吃的天数不断地变化.…… 相似文献
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导数作为大学的重要内容,进入中学数学教材后,给传统的内容注入了生机与活力,为中学数学命题的研究提供了新视角,新方法.由于导数是研究函数性质的一个很好的工具,它的用途十分广泛,它在解决函数、不等式、解析几何等问题有独到的功能.因此,近几年的高考正逐年加大对导数问题的考查力度,本文通过对07年全国各地高考题的整理和分析寻找命题规律,希望能对今后的教学提供一点复习思路.…… 相似文献
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利用极值理论来考虑上证综指收益率的尾部.为了选择合理的超越门限,采用平均剩余函数和De-Haan矩估计相结合的方法.在学生t分布和广义误差分布的新患假设下,用GARCH和EGARCH新息的ARMA模型拟合指数收益率,并且使用极值理论的极大似然方法估计模型残差的尾指,估计结果表明收益率的尾指和模型的残差尾指基本一致. 相似文献
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V. Yegnanarayanan 《Southeast Asian Bulletin of Mathematics》2000,24(1):129-136
The pseudoachromatic number of a graph G is the maximum size of a vertex partition of G (where the sets of the partition may or may not be independent) such that, between any two distinct parts, there is at least one edge of G. This parameter is determined for graphs such as cycles, paths, wheels, certain complete multipartite graphs, and for other classes of graphs. Some open problems are raised.AMS Subject Classification (1991): primary 05C75 secondary 05C85 相似文献
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Bogdan Oporowski 《Discrete Mathematics》2009,309(9):2948-2951
We generalize the Five-Color Theorem by showing that it extends to graphs with two crossings. Furthermore, we show that if a graph has three crossings, but does not contain K6 as a subgraph, then it is also 5-colorable. We also consider the question of whether the result can be extended to graphs with more crossings. 相似文献
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Bohdan Zelinka 《Czechoslovak Mathematical Journal》2005,55(2):393-396
The restrained domination number r(G) and the total restrained domination number
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(G) of a graph G were introduced recently by various authors as certain variants of the domination number (G) of (G). A well-known numerical invariant of a graph is the domatic number d(G) which is in a certain way related (and may be called dual) to (G). The paper tries to define analogous concepts also for the restrained domination and the total restrained domination and discusses the sense of such new definitions.This research was supported by Grant MSM 245100303 of the Ministry of Education, Youth and Sports of the Czech Republic. 相似文献
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1. IntroductionSince WOodall gave out the concept of biIldi11g Ilu1lJber in 1973[l] ! the bil1ding nunlber fOrsome specia1 classes have beeIl studied by Kane and WaIlg Jianfang[']. Mirolawa Skowronskahave studied the binding number of Halin-graph[']. ZI1ang Zhongfu, Liu Li1lzhong andZhang Jianxun have extended the bil1di11g nuInber to the edges and studied tlle edge-bindingnumber of path, cycle, coInplete grapl1. I1l this paper, we study the edge-binding number ofouter plane graph, Ha… 相似文献
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The generalized Mycielskians (also known as cones over graphs) are the natural generalization of the Mycielski graphs (which were first introduced by Mycielski in 1955). Given a graph G and any integer m?0, one can transform G into a new graph μm(G), the generalized Mycielskian of G. This paper investigates circular clique number, total domination number, open packing number, fractional open packing number, vertex cover number, determinant, spectrum, and biclique partition number of μm(G). 相似文献
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本文研究了带多重右边的不定最小二乘问题的条件数,给出了范数型、混合型及分量型条件数的表达式,同时,也给出了相应的结构条件数的表达式.所考虑的结构矩阵包含Toeplitz 矩阵、Hankel矩阵、对称矩阵、三对角矩阵等线性结构矩阵与Vandermonde矩阵、Cauchy矩阵等非线性结构矩阵.数值例子显示结构条件数总是紧于非结构条件数. 相似文献
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The problem to find the nearest trapezoidal approximation of a fuzzy number with respect to a well-known metric, which preserves the expected interval of the fuzzy number, is completely solved. The previously proposed approximation operators are improved so as to always obtain a trapezoidal fuzzy number. Properties of this new trapezoidal approximation operator are studied. 相似文献
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We sho that the universal embedding dimensions (over F
2) of the near polygons associated ith Sym(2n) (vieed as subgroup of Sp1(2n - 2, 2)) are the Catalan numbers. 相似文献