一个指标为3的Mendelsohn三元系,记为MTS(v,3),是一个对子(X,B,其中X是一个v元集,B是X中循环三元组(区组)的集合,满足X的每一个有序对都恰包含于B中的3个区组.设(X,B是一个没有重复区组的MTS(v,3),如果(x,y,z)∈B必有(z,y,x)B则称(X,B为单纯的,记为PMTS(v,3).不相交PMTS(v,3)大集,记为LPMTS(v,3),是一个集合(X,B)}i,其中每个(X,B)都是一个PMTS(v,3),并且UiBi构成了X中所有循环三元组的一个划分.本文给出了LPMTS(v,3)的一种构造方法,得到了其存在的一个无穷类:对于v=8,14(mod18),v≠14,存在LPMTS(v,3).
A Mendelsohn triple system of order v with index 3, briefly by MTS(v,3), is a pair (X, B), where X is a v-set and Bis a eolleetion of cyclie triples on X such that every ordered pair of X belongs to exactly 3 cyclic triples of 2.. A M TS(v,3) without repeated blocks is called pure and denoted by PMTS( v ,3) if ( x, y, z) ∈Bimplies ( z, y, x) B. A large set of disjoint PMTS( v ,3), denoted by LPMTS( v ,3), is a collection t ( X ,Bi) }i, such that each ( X ,Bi) is a PMTS( v ,3), and U Bi is a partition of all cyclic triples on X. In this paper, we give a construction for LPMTS( v ,3), and obtain an infinite family for the existence of LPM T S( v, 3):for any v ≡8,14(mod 18), v ≠ 14, there exists an LPMTS(v,3).