A dominating set D of a graph G is a subset of V (G) such that for every vertex v ∈ V (G), either in v ∈ D or there exists a vertex u ∈ D that is adjacent to v. We are interested in finding dominating sets of small cardinality. A dominating set I of a graph G is said to be independent if no two vertices of I are connected by an edge of G. The size of a smallest independent dominating set of a g...

The independent domination number of a graph is the smallest cardinality of an independent set that dominates the graph. In this paper we consider the independent domination number of triangle-free graphs. We improve several of the known bounds as a function of the order and minimum degree, thereby answering conjectures of Haviland.

Let G = (V,E) be a graph. A set S ⊆ V is a total restrained dominating set if every vertex is adjacent to a vertex in S and every vertex of V − S is adjacent to a vertex in V − S. A set S ⊆ V is a restrained dominating set if every vertex in V − S is adjacent to a vertex in S and to a vertex in V − S. The total restrained domination number of G (restrained domination number of G, respectively),...

Let G = (V,E) be a graph. A total restrained dominating set is a set S ⊆ V where every vertex in V \ S is adjacent to a vertex in S as well as to another vertex in V \S, and every vertex in S is adjacent to another vertex in S. The total restrained domination number of G, denoted by γ r (G), is the smallest cardinality of a total restrained dominating set of G. We determine lower and upper boun...

In this paper we introduce a general strategy for approximating the solution to minimisation problems in random regular graphs. We describe how the approach can be applied to the minimum vertex cover (MVC), minimum independent dominating set (MIDS) and minimum edge dominating set (MEDS) problems. In almost all cases we are able to improve the best known results for these problems. Results for t...

In ad hoc wireless networks, a connected dominating set can be used as a virtual backbone to improve the performance. Many constructions for approximating the minimum connected dominating set are based on the construction of a maximal independent set. The relation between the sizemis(G) of a maximum independent set and the size cds(G) of a minimum connected dominating set in the same graph G pl...

We prove that for every tree T of order at least 2 and every minimum dominating set D of T which contains at most one endvertex of T , there is an independent dominating set I of T which is disjoint from D. This confirms a recent conjecture of Johnson, Prier, and Walsh.

Connected dominating set (CDS) has a wide range of applications in wireless ad hoc networks. A number of approximation algorithms for constructing a small CDS in wireless ad hoc networks have been proposed in the literature. The majority of these algorithms follow a general two-phased approach. The first phase constructs a dominating set, and the second phase selects additional nodes to interco...

A subset D?V is an independent (or stable) dominating set of a graph G=(V,E) if D (i.e., there are no edges between vertices D) and dominates all the G (each vertex V?D has neighbour in D). In this paper, we study generalisation classical notion. Namely, instance our problem partition ?=(V1,…,Vk) V. Each Vi ? called obligation. An Independent Dominating with Obligations (IDO) (G,?) additional p...