一类含两个圈的特殊本原双色有向图的指数  

Exponents of a Class of Special and Primitive Two-Colored Digraphs with Two Cycles

作　　者：张晓东[1] 邵燕灵[1] 

机构地区：[1]中北大学理学院,山西太原030051

出　　处：《中北大学学报（自然科学版）》2012年第3期221-227,231,共8页Journal of North University of China(Natural Science Edition)

基　　金：国家自然科学基金资助项目(10571163);山西省自然科学基金资助项目(2007011017)

摘　　要：一个双色有向图D是本原的,如果存在非负整数h和k,h+k>0,使得D的每对顶点(i,j)都存在从i到j的(h,k)-途径,称h+k的最小值为本原双色有向图D的指数.给出了一类含两个圈的特殊本原双色有向图指数的紧的上下界,并对一类特殊情况进行了极图刻划.A two-colored digraph D is primitive if there exist nonnegative integers h and k with h+k>0 such that for each pair(i,j) of vertices there exists an(h,k)-walk in D from i to j. The exponent of the primitive two-colored digraph D is defined as the minimum value of h+k taken over all such h and k.The tight upper bounds and lower bounds of exponents of a class of special and primitive two-colored digraphs with two cycles was given,and give the characterizations of one type extremal two-colored digraphs was given.

关 键 词：本原双色有向图 指数 极图刻划 

分 类 号：O157.5[理学—数学]