Results 51 to 60 of about 30,213,529 (145)

A note on odd colorings of 1-planar graphs

open access: yesDiscrete Applied Mathematics, 2023
A proper coloring of a graph is odd if every non-isolated vertex has some color that appears an odd number of times on its neighborhood. This notion was recently introduced by Petruševski and Škrekovski, who proved that every planar graph admits an odd $9$-coloring; they also conjectured that every planar graph admits an odd $5$-coloring. Shortly after,
Daniel W. Cranston   +2 more
openaire   +3 more sources

Testing hereditary properties of nonexpanding bounded-degree graphs [PDF]

open access: yes, 2007
We study graph properties that are testable for bounded-degree graphs in time independent of the input size. Our goal is to distinguish between graphs having a predetermined graph property and graphs that are far from every graph having that property. It
Christian Sohler   +5 more
core   +1 more source

On the Maximum Independent Set Problem in Subclasses of Planar Graphs

open access: yesJournal of Graph Algorithms and Applications, 2010
The maximum independent set problem is known to be NP-hard in the class of planar graphs. In the present paper, we study its complexity in hereditary subclasses of planar graphs.
Vadim Lozin, Martin Milanič
doaj   +1 more source

1-planar unit distance graphs

open access: yesEuropean Journal of Combinatorics
15 pages, 8 ...
Panna Gehér, Géza Tóth 0001
openaire   +7 more sources

Total Semirelib Graph [PDF]

open access: yes, 2013
In this paper, the concept of Total semirelib graph of a planar graph is introduced. Authors present a characterization of those graphs whose total semirelib graphs are planar, outer planar, Eulerian, hamiltonian with crossing number ...
Prasad, Manjunath   +3 more
core   +1 more source

L(2, 1)-Labelings of Some Families of Oriented Planar Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2014
In this paper we determine, or give lower and upper bounds on, the 2-dipath and oriented L(2, 1)-span of the family of planar graphs, planar graphs with girth 5, 11, 16, partial k-trees, outerplanar graphs and cacti.
Sen Sagnik
doaj   +1 more source

Knot Graphs [PDF]

open access: yes, 2000
We consider the equivalence classes of graphs induced by the unsigned versions of the Reidemeister moves on knot diagrams. Any graph which is reducible by some finite sequence of these moves, to a graph with no edges is called a knot graph.
Welsh, D J A   +13 more
core   +1 more source

On the Book Thickness of 1-Planar Graphs

open access: yesCoRR, 2015
In a book embedding of a graph G, the vertices of G are placed in order along a straight-line called spine of the book, and the edges of G are drawn on a set of half-planes, called the pages of the book, such that two edges drawn on a page do not cross each other. The minimum number of pages in which a graph can be embedded is called the book-thickness
Md. Jawaherul Alam   +2 more
openaire   +3 more sources

NP-Completeness Results for Minimum Planar Spanners [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 1998
For any fixed parameter t greater or equal to 1, a t-spanner of a graph G is a spanning subgraph in which the distance between every pair of vertices is at most t times their distance in G.
Ulrik Brandes, Dagmar Handke
doaj   +2 more sources

Coalition structure generation over graphs [PDF]

open access: yes, 2012
We give the analysis of the computational complexity of coalition structure generation over graphs. Given an undirected graph G = (N,E) and a valuation function v : P(N) → R over the subsets of nodes, the problem is to find a partition of N into ...
Polukarov, Maria   +5 more
core   +1 more source

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