单双圈间隔的双色有向圈的本原指数  

Exponents of a Class of Two-Colored Digraphs with Directed and Double Directed Cycles Alternated

作　　者：林建青[1] 

机构地区：[1]大同大学朔州师范分校数计系,山西朔州036002

出　　处：《太原师范学院学报（自然科学版）》2012年第2期16-19,29,共5页Journal of Taiyuan Normal University:Natural Science Edition

摘　　要：一个双色有向图D是本原的,当且仅当存在非负整数h和k,且h+k>0,使得D中的每一对顶点(i,j)都存在从i到j的(h,k)-途径,称h+k的最小值为D的本原指数.利用代数与图论的方法,研究了一类单双圈间隔的双色有向圈的本原指数,给出了本原条件和本原指数上界,并对达到本原指数上界的极图进行了刻画.A two-colored digraph D is primitive if and only if there exist nonnegative integers h and k with h＋k〉O such that for each pair （i,j） of vertices there exists an （h,k）-walk in D from i to j. The ex- ponent of the primitive two-colored digraph D is the minimum value of h＋k taken over all such h and k. To study the exponents of a class of two-colored digraphs with directed and double directed cycles alternated, give some primitive conditions and a upper bound on the exponents. Further give the characterization of the extremal two-colored digraphs.

关 键 词：双色有向图 本原指数 途径 极图刻画 

分 类 号：O157[理学—数学]