PBIB-Designs from Certain Subsets of Distance-Regular Graphs

Partially balanced incomplete block (PBIB)-designs are well known to be the generalization of combinatorial 2-designs. In this paper, we first construct PBIB-designs from diametral paths of distance-regular graphs, which generalizes the result for strongly regular graphs. Furthermore, for Q-polynomial distance-regular graphs associated with regular semilattices, we obtain the construction of PBIB-designs through descendents with fixed dual width.