Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Roman bondage in graphs

100%

Rad N., Volkmann L.

Discussiones Mathematicae Graph Theory

2011

tom 31

nr 4

763-773

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 $γ_R(G -E') > γ_R(G)$. We determine the Roman bondage number in several classes of graphs and give some sharp bounds.

On the intersection graphs of ideals of direct product of rings

81%

Rad N., Jafari S., Ghosh S.

Discussiones Mathematicae - General Algebra and Applications

2014

tom 34

nr 2

191-201

In this paper we first calculate the number of vertices and edges of the intersection graph of ideals of direct product of rings and fields. Then we study Eulerianity and Hamiltonicity in the intersection graph of ideals of direct product of commutative rings.

Ograniczanie wyników

1 Discussiones Mathematicae - General Algebra and Applications

1 Discussiones Mathematicae Graph Theory

2 Rad N.

1 Ghosh S.

1 Jafari S.

1 Volkmann L.

1 2014

1 2011

Wyniki wyszukiwania

Roman bondage in graphs

On the intersection graphs of ideals of direct product of rings