Tactical decomposable regular group divisible designs and their threshold schemes

Abstract

Some methods of decomposing $v(=mn)\times b$ incidence matrix of regular group divisible (RGD) designs into square submatrices of order $m$ are described. Such designs are known as tactical decomposable designs. As a by–product, resolvable solutions of some RGD designs are obtained. A relationship between tactical decomposable designs and $(2,n)-$threshold schemes is also given.