Results 31 to 40 of about 850,474 (224)

Site percolation and isoperimetric inequalities for plane graphs

open access: yesRandom Structures &Algorithms, Volume 58, Issue 1, Page 150-163, January 2021., 2021
We use isoperimetric inequalities combined with a new technique to prove upper bounds for the site percolation threshold of plane graphs with given minimum degree conditions. In the process we prove tight new isoperimetric bounds for certain classes of hyperbolic graphs.
John Haslegrave, Christoforos Panagiotis
wiley   +1 more source

Approximation of pathwidth of outerplanar graphs [PDF]

open access: yesJournal of Algorithms, 2001
Summary: There exists a polynomial time algorithm to compute the pathwidth of outerplanar graphs, but the large exponent makes this algorithm impractical. In this paper, we give an algorithm that, given a biconnected outerplanar graph \(G\), finds a path decomposition of \(G\) of pathwidth at most twice the pathwidth of \(G\) plus one.
Hans L. Bodlaender, Fedor V. Fomin
openaire   +8 more sources

Strong Chromatic Index of Outerplanar Graphs

open access: yesAxioms, 2022
The strong chromatic index χs′(G) of a graph G is the minimum number of colors needed in a proper edge-coloring so that every color class induces a matching in G. It was proved In 2013, that every outerplanar graph G with Δ≥3 has χs′(G)≤3Δ−3.
Ying Wang   +3 more
doaj   +1 more source

Optimal maximal graphs [PDF]

open access: yesTransactions on Combinatorics, 2022
An optimal labeling of a graph with $n$ vertices and $m$ edges is an injective assignment of the first $n$ nonnegative integers to the vertices‎, ‎that induces‎, ‎for each edge‎, ‎a weight given by the sum of the labels of its end-vertices with the ...
Christian Barrientos, Maged Youssef
doaj   +1 more source

Clique-Relaxed Graph Coloring [PDF]

open access: yes, 2011
We define a generalization of the chromatic number of a graph G called the k-clique-relaxed chromatic number, denoted χ(k)(G). We prove bounds on χ(k)(G) for all graphs G, including corollaries for outerplanar and planar graphs.
Dunn, Charles   +5 more
core   +2 more sources

A generalization of outerplanar graphs

open access: yesDiscrete Mathematics, 1984
A graph G is said to be W-outerplanar if it can be embedded in the plane so that all vertices of a given set \(W\subset V(G)\) lie on the boundary of one face. A characterization of such graphs is given by means of forbidden subgraphs, and an algorithm for W-outerplanarity testing is described. The results overlap, in part, with those of \textit{V.
Lía Oubiña, R. Zucchello
openaire   +3 more sources

Alpha Labeling of Amalgamated Cycles

open access: yesTheory and Applications of Graphs, 2022
A graceful labeling of a bipartite graph is an \a-labeling if it has the property that the labels assigned to the vertices of one stable set of the graph are smaller than the labels assigned to the vertices of the other stable set.
Christian Barrientos
doaj   +1 more source

Space-Efficient Biconnected Components and Recognition of Outerplanar Graphs [PDF]

open access: yes, 2016
We present space-efficient algorithms for computing cut vertices in a given graph with $n$ vertices and $m$ edges in linear time using $O(n+\min\{m,n\log \log n\})$ bits.
Kammer, Frank   +2 more
core   +2 more sources

Definability Equals Recognizability for $k$-Outerplanar Graphs [PDF]

open access: yes, 2015
One of the most famous algorithmic meta-theorems states that every graph property that can be defined by a sentence in counting monadic second order logic (CMSOL) can be checked in linear time for graphs of bounded treewidth, which is known as Courcelle ...
Bodlaender, Hans L., Jaffke, Lars
core   +5 more sources

Monitoring maximal outerplanar graphs [PDF]

open access: yesElectronic Notes in Discrete Mathematics, 2014
In this paper we define a new concept of monitoring the elements of triangulation graphs by faces. Furthermore, we analyze this, and other monitoring concepts (by vertices and by edges), from a combinatorial point of view, on maximal outerplanar graphs.
Martins, Mafalda, Hernández, Gregorio
openaire   +3 more sources

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