一个参数为(v,λ)的Mendelsohn三元系。记为MTS(v,λ),是一个对子(X,B),其中X是一个v元集,B是X中循环三元组的集合,满足X的每一个有序对都恰包含于B中λ个循环三元组.设(X,B)是一个没有重复循环三元组的MTS(v,λ),如果满足(x,y,z)∈B必有(x,y,z) 不属于B,则称(X,B)为单纯的,记为PMTS(v,λ).不相交PMTS(v,λ)大集,记为LPMTS(v,λ),是一个集合{(X,Bi)}i,其中每个(X,Bi)都是一个PMTS(v,λ),并且∪iBi构成了X中所有循环三元组的一个划分.本文给出了LPMTS(v,λ)的一些构造方法及存在性结果,最终完成了LPMTS(v,2)的存在谱.
A Mendelsohn triple system of order v with indexλ,briefly,MTS(v,λ),is a pair(X,B)where X is a v-set and B is a collection of cyclic triples on X such that every ordered pair of X belongs to exactlyλcyclic triples of B.An MTS(v,λ)without repeated blocks is called pure and denoted by PMTS(v,λ)if(x,y,z)∈B implies(x,y,z) B.A large set of disjoint PMTS(v,λ)denoted by LPMTS(v,λ),is a collection of v-2/λ disjoint pure Mendelsohn triple systems on X,and∪iBi is a partition of all cyclic triples from X. In this paper,some results about the existence for LPMTS(v,λ)are obtained.Finally we complete the spectrum for the existence of an LPMTS(v,2).