On directed trades


A (v, k, t) directed trade (or simply a (v, k, t)DT) of volume s consists of two disjoint collections Tl and each containing ordered k-tuples of distinct elements of a v-set called blocks, such that the number of blocks containing any t-tuple of V is the same in Tl as in T2 . Our study shows that the volume of a (v, k, t)DT is at least 2Lt/ 2J and that… (More)