最优分派问题的一些推广

分派问题是运筹学中一个具有理论意义又很有实际应用价值的问题.其一般提法是:设有n个工人A_1,…,A_n,需要分派他们去做n件工作B_1,…,B_n由于技术水平等原因,他们做任一种工作的效率可能不同,因而创造的价值也不同.应如何安排,才能使创造的总价值最大。这个问题等价于在一个赋权完全二部图中寻找一个最大权对集、这种对集称为     

二部竞赛图中含指定点对的互补回路

设R是任一个k-正则二部竞赛图(k≥2),对R中任意两个不同的点u,v,R中存在一对点不相交且分别具有长4和4K-4的回路C_1、C_2,使得u在C_1上,v在C_2上,除非R同构于R_(494)~*。     

货运汽车调度的数学模型及新的启发式算法

本文在分析研究国内外较为流行的几个货运汽车调度模型和算法的基础上,给出一种新的数学模型和启发式算法,并且可以在微型计算机上实现.     

完全图的Cantesian积的L(2,1)-圆标定

For positive integers j and k with j ≥ k, an L（j, k）-labeling of a graph G is an assignment of nonnegative integers to V（G） such that the difference between labels of adjacent vertices is at least j, and the difference between labels of vertices that are distance two apart is at least k. The span of an L（j, k）-labeling of a graph G is the difference between the maximum and minimum integers it uses. The λj, k-number of G is the minimum span taken over all L（j, k）-labelings of G. An m-（j, k）-circular labeling of a graph G is a function f ： V（G） →{0, 1, 2,..., m - 1} such that ｜f（u） - f（v）｜m ≥ j if u and v are adjacent; and ｜f（u） - f（v）｜m 〉 k ifu and v are at distance two, where ｜x｜m = min{｜xl｜, m-｜x｜}. The minimum integer m such that there exists an m-（j, k）-circular labeling of G is called the σj,k-number of G and is denoted by σj,k（G）. This paper determines the σ2,1-number of the Cartesian product of any three complete graphs.