Pairwise Balanced Designs Arising from Minimum Covering and Maximum Independent Sets of Circulant Graphs.

The pairwise balanced designs (PBD's) is a pair (P;B), where P is a finite set of v points and B is a family of subsets of P, called blocks such that every two distinct points in P appear in exactly one block. Let α(G) = α and β(G) = β be the vertex covering and independence number of a graph G = (V;E) with the minimum and maximum cardinality of such sets are denoted by α-sets and β-sets of G, respectively (or, simply (α; β)-sets). In this paper, we obtain the total number of (α; β)-sets in different jump sizes of some circulant graphs apart from strongly regular graphs which are the blocks of PBD. [ABSTRACT FROM AUTHOR]