Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Directed graph

Sortuj według:

Ogranicz wyniki do:

Coupled fixed point theorems in complete metric spaces endowed with a directed graph and application

100%

Kir M., Yolacan E., Kiziltunc H.

Open Mathematics

2017

tom 15

nr 1

734-744

The purpose of this paper is to present some existence results for coupled fixed point of a (φ,ψ) -contractive condition for mixed monotone operators in metric spaces endowed with a directed graph. Our results generalize the results obtained by Jain et al. in (International Journal of Analysis, Volume 2014, Article ID 586096, 9 pages). Moreover, we have an application to some integral system to support the results.

The signed k-domination number of directed graphs

100%

Atapour M., Sheikholeslami S., Hajypory R., Volkmann L.

Open Mathematics

2010

tom 8

nr 6

1048-1057

Let k ≥ 1 be an integer, and let D = (V; A) be a finite simple digraph, for which d D− ≥ k − 1 for all v ɛ V. A function f: V → {−1; 1} is called a signed k-dominating function (SkDF) if f(N −[v]) ≥ k for each vertex v ɛ V. The weight w(f) of f is defined by $$ \sum\nolimits_{v \in V} {f(v)} $$. The signed k-domination number for a digraph D is γkS(D) = min {w(f|f) is an SkDF of D. In this paper, we initiate the study of signed k-domination in digraphs. In particular, we present some sharp lower bounds for γkS(D) in terms of the order, the maximum and minimum outdegree and indegree, and the chromatic number. Some of our results are extensions of well-known lower bounds of the classical signed domination numbers of graphs and digraphs.

Ograniczanie wyników

2 Open Mathematics

1 Atapour M.

1 Hajypory R.

1 Kir M.

1 Kiziltunc H.

1 Sheikholeslami S.

1 Volkmann L.

1 Yolacan E.

1 2017

1 2010

Wyniki wyszukiwania

Coupled fixed point theorems in complete metric spaces endowed with a directed graph and application

The signed k-domination number of directed graphs