An Italian dominating function on a (di)graph G with vertex set V ( ) is f : → { 0 , 1 2 } such that every v ∈ = has an (in)neighbour assigned or two (in)neighbours 1. We complete the investigation of domination numbers Cartesian products directed cycles.

A domination graph of a digraph D, dom (D), is created using thc vertex set of D and edge uv E E (dom (D)) whenever (u, z) E A (D) or (v, z) E A (D) for any other vertex z E V (D). Here, we consider directed graphs whose underlying graphs are isomorphic to their domination graphs. Specifically, digraphs are completely characterized where UG (D) is the union of two disjoint paths.

Let Y be a subset of real numbers. A Y dominating function of a graph G = (V, E) is a function f : V → Y such that u∈NG[v] f(u) ≥ 1 for all vertices v ∈ V , where NG[v] = {v} ∪ {u|(u, v) ∈ E}. Let f(S) = u∈S f(u) for any subset S of V and let f(V ) be the weight of f . The Y -domination problem is to find a Y -dominating function of minimum weight for a graph. In this paper, we study the variat...

A set S ⊆ V of vertices in a graph G = (V,E) is called a dominating set if every vertex in V − S is adjacent to at least one vertex in S. Domination in graphs is a well-studied branch of graph theory, and is the subject of two books by Haynes, Hedetniemi and Slater [8, 9]. However, about 90% of the papers on domination have considered only undirected graphs. Thus, relatively little is known abo...

In a graph G, a vertex is said to dominate itself and all of its neighbors. For a fixed positive integer k, the k-tuple domination problem is to find a minimum sized vertex subset in a graph such that every vertex in the graph is dominated by at least k vertices in this set. The current paper studies k-tuple domination in graphs from an algorithmic point of view. In particular, we give a linear...

Let ~ Pm ~ Cn be the Cartesian product of the directed path ~ Pm and the directed cycle ~ Cn. In this paper, we give the exact value of the domination number and the signed 2-independence number of ~ Pm ~ Cn for any integers m and n. ∗ Supported by the Academy of Finland, Grant No. 132122. † Supported in part by the Foundation for distinguished Young Teachers, Shanghai Education Committee (No. ...

The claim that workers are subject to structural domination in the labor market is a central contention of recent radical turn republican political theory, but it remains undertheorized. Two core components—the have “no reasonable alternative” selling their capitalists and relevance exposure potential interference such cases—remain unclear. Without more precise specification conditions dominati...