Currently displaying 1 – 10 of 10

Showing per page

Order by Relevance | Title | Year of publication

Strong Equality Between the Roman Domination and Independent Roman Domination Numbers in Trees

Mustapha ChellaliNader Jafari Rad — 2013

Discussiones Mathematicae Graph Theory

A Roman dominating function (RDF) on a graph G = (V,E) is a function f : V −→ {0, 1, 2} satisfying the condition that every vertex u for which f(u) = 0 is adjacent to at least one vertex v for which f(v) = 2. The weight of an RDF is the value f(V (G)) = P u2V (G) f(u). An RDF f in a graph G is independent if no two vertices assigned positive values are adjacent. The Roman domination number R(G) (respectively, the independent Roman domination number iR(G)) is the minimum weight of an RDF (respectively,...

Characterization of Cubic Graphs G with ir t (G) = Ir t (G) = 2

Changiz EslahchiShahab HaghiNader Jafari — 2014

Discussiones Mathematicae Graph Theory

A subset S of vertices in a graph G is called a total irredundant set if, for each vertex v in G, v or one of its neighbors has no neighbor in S −{v}. The total irredundance number, ir(G), is the minimum cardinality of a maximal total irredundant set of G, while the upper total irredundance number, IR(G), is the maximum cardinality of a such set. In this paper we characterize all cubic graphs G with irt(G) = IRt(G) = 2

Roman bondage in graphs

Nader Jafari RadLutz Volkmann — 2011

Discussiones Mathematicae Graph Theory

A Roman dominating function on a graph G is a function f:V(G) → 0,1,2 satisfying the condition that every vertex u for which f(u) = 0 is adjacent to at least one vertex v for which f(v) = 2. The weight of a Roman dominating function is the value f ( V ( G ) ) = u V ( G ) f ( u ) . The Roman domination number, γ R ( G ) , of G is the minimum weight of a Roman dominating function on G. In this paper, we define the Roman bondage b R ( G ) of a graph G with maximum degree at least two to be the minimum cardinality of all sets E’ ⊆ E(G) for which γ R ( G - E ' ) > γ R ( G ) ....

On The Roman Domination Stable Graphs

Majid HajianNader Jafari Rad — 2017

Discussiones Mathematicae Graph Theory

A Roman dominating function (or just RDF) on a graph G = (V,E) is a function f : V → {0, 1, 2} satisfying the condition that every vertex u for which f(u) = 0 is adjacent to at least one vertex v for which f(v) = 2. The weight of an RDF f is the value f(V (G)) = Pu2V (G) f(u). The Roman domination number of a graph G, denoted by R(G), is the minimum weight of a Roman dominating function on G. A graph G is Roman domination stable if the Roman domination number of G remains unchanged under removal...

Bounds on the Locating Roman Domination Number in Trees

Nader Jafari RadHadi Rahbani — 2018

Discussiones Mathematicae Graph Theory

A Roman dominating function (or just RDF) on a graph G = (V, E) is a function f : V → 0, 1, 2 satisfying the condition that every vertex u for which f(u) = 0 is adjacent to at least one vertex v for which f(v) = 2. The weight of an RDF f is the value f(V (G)) = ∑u∈V(G) f(u). An RDF f can be represented as f = (V0, V1, V2), where Vi = v ∈ V : f(v) = i for i = 0, 1, 2. An RDF f = (V0, V1, V2) is called a locating Roman dominating function (or just LRDF) if N(u) ∩ V2 ≠ N(v) ∩ V2 for any pair u, v of...

Various Bounds for Liar’s Domination Number

Abdollah AlimadadiDoost Ali MojdehNader Jafari Rad — 2016

Discussiones Mathematicae Graph Theory

Let G = (V,E) be a graph. A set S ⊆ V is a dominating set if Uv∈S N[v] = V , where N[v] is the closed neighborhood of v. Let L ⊆ V be a dominating set, and let v be a designated vertex in V (an intruder vertex). Each vertex in L ∩ N[v] can report that v is the location of the intruder, but (at most) one x ∈ L ∩ N[v] can report any w ∈ N[x] as the intruder location or x can indicate that there is no intruder in N[x]. A dominating set L is called a liar’s dominating set if every v ∈ V (G) can be correctly...

Page 1

Download Results (CSV)