Results 51 to 60 of about 96 (83)

On the number of spanning trees, the Laplacian eigenvalues, and the Laplacian Estrada index of subdivided-line graphs

open access: yesOpen Mathematics, 2016
As a generalization of the Sierpiński-like graphs, the subdivided-line graph Г(G) of a simple connected graph G is defined to be the line graph of the barycentric subdivision of G.
Shang Yilun
doaj   +1 more source

Niche Hypergraphs of Products of Digraphs

open access: yesDiscussiones Mathematicae Graph Theory, 2020
If D = (V, A) is a digraph, its niche hypergraph Nℋ(D) = (V, ℰ) has the edge set ℰ={e⊆V||e|≥2∧∃ υ∈V:e=ND−(υ)∨e=ND+(υ)}{\cal E} = \{ {e \subseteq V| | e | \ge 2 \wedge \exists \, \upsilon \in V:e = N_D^ - ( \upsilon ) \vee e = N_D^ + ( \upsilon ...
Sonntag Martin, Teichert Hanns-Martin
doaj   +1 more source

Three-arc graphs: characterization and domination

open access: yes, 2014
An arc of a graph is an oriented edge and a 3-arc is a 4-tuple (v, u, x, y) of vertices such that both (v, u, x) and (u, x, y) are paths of length two. The 3-arc graph of a graph G is defined to have vertices the arcs of G such that two arcs uv, xy are ...
Guangjun Xu, Sanming Zhou
core  

The Page Number Problem for Partially Ordered Sets

open access: yes, 2013
Umieszczenie grafu w książce jest definiowane przez kolejność jego wierzchołków na grzbiecie książki i przyporządkowanie jego krawędzi stronom książki tak, aby na żadnej stronie krawędzie nie przecinały się. Umieszczenie zbioru częściowo uporządkowanego (
Kwiatkowska, Anna Beata
core  

One-Three Join: A Graph Operation and Its Consequences

open access: yesDiscussiones Mathematicae Graph Theory, 2017
In this paper, we introduce a graph operation, namely one-three join. We show that the graph G admits a one-three join if and only if either G is one of the basic graphs (bipartite, complement of bipartite, split graph) or G admits a constrained ...
Shalu M.A., Devi Yamini S.
doaj   +1 more source

On Accurate Domination in Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2019
A dominating set of a graph G is a subset D ⊆ VG such that every vertex not in D is adjacent to at least one vertex in D. The cardinality of a smallest dominating set of G, denoted by γ(G), is the domination number of G. The accurate domination number of
Cyman Joanna   +2 more
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On Two Generalized Connectivities of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2018
The concept of generalized k-connectivity κk(G), mentioned by Hager in 1985, is a natural generalization of the path-version of the classical connectivity.
Sun Yuefang, Li Fengwei, Jin Zemin
doaj   +1 more source

Computing the Metric Dimension of a Graph from Primary Subgraphs

open access: yesDiscussiones Mathematicae Graph Theory, 2017
Let G be a connected graph. Given an ordered set W = {w1, . . . , wk} ⊆ V (G) and a vertex u ∈ V (G), the representation of u with respect to W is the ordered k-tuple (d(u, w1), d(u, w2), . . .
Kuziak Dorota   +2 more
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