For a vertex u in the dominating set D of a graph G, the number of edges from u to V--D is
called the outdegree of u with respect to D, d< sup> o< sub> D, G(u). A dominating set D is …

A hub set in a graph G is a set H⊆ V (G) such that any two vertices outside H are connected
by a path whose all intermediate vertices lie in H. The minimum cardinality of a hub set is …