Results 21 to 30 of about 38,199 (317)

A Planarity Criterion for Graphs [PDF]

open access: yesSIAM Journal on Discrete Mathematics, 2015
It is proven that a connected graph is planar if and only if all its cocycles with at least four edges are "grounded" in the graph. The notion of grounding of this planarity criterion, which is purely combinatorial, stems from the intuitive idea that with planarity there should be a linear ordering of the edges of a cocycle such that in the two ...
Kosta Dosen, Zoran Petric
openaire   +3 more sources

NIC-planar graphs

open access: yesDiscrete Applied Mathematics, 2017
A graph is NIC-planar if it admits a drawing in the plane with at most one crossing per edge and such that two pairs of crossing edges share at most one common end vertex. NIC-planarity generalizes IC-planarity, which allows a vertex to be incident to at most one crossing edge, and specializes 1-planarity, which only requires at most one crossing per ...
Christian Bachmaier   +4 more
openaire   +2 more sources

The Liouville and the intersection properties are equivalent for planar graphs [PDF]

open access: yes, 2012
It is shown that if a planar graph admits no non-constant bounded harmonic function then the trajectories of two independent simple random walks intersect almost ...
Itai Benjamini   +5 more
core   +1 more source

Computational Study on a PTAS for Planar Dominating Set Problem

open access: yesAlgorithms, 2013
The dominating set problem is a core NP-hard problem in combinatorial optimization and graph theory, and has many important applications. Baker [JACM 41,1994] introduces a k-outer planar graph decomposition-based framework for designing polynomial time ...
Qian-Ping Gu, Marjan Marzban
doaj   +1 more source

Minimum Cycle Base of Graphs Identified by Two Planar Graphs [PDF]

open access: yes, 2007
In this paper, we study the minimum cycle base of the planar graphs obtained from two 2-connected planar graphs by identifying an edge (or a cycle) of one graph with the corresponding edge (or cycle) of another, related with map geometries, i.e ...
Han, Ren, Dengju, Ma
core   +1 more source

On certain prime cordial families of graphs

open access: yesJournal of Taibah University for Science, 2020
Graph labelling is an important tool in modelling real life problems. In the present paper, different graph families are studied for prime cordial labelling.
Nazeran Idrees   +3 more
doaj   +1 more source

Sufficient Conditions of 6-Cycles Make Planar Graphs DP-4-Colorable

open access: yesMathematics, 2022
In simple graphs, DP-coloring is a generalization of list coloring and thus many results of DP-coloring generalize those of list coloring. Xu and Wu proved that every planar graph without 5-cycles adjacent simultaneously to 3-cycles and 4-cycles is 4 ...
Kittikorn Nakprasit   +2 more
doaj   +1 more source

Planar and poly-arc Lombardi drawings

open access: yesJournal of Computational Geometry, 2018
In Lombardi drawings of graphs, edges are represented as circular arcs and the edges incident on vertices have perfect angular resolution. It is known that not every planar graph has a planar Lombardi drawing.
Christian A. Duncan   +5 more
doaj   +1 more source

Good triangulations yield good tours [PDF]

open access: yes, 2008
Consider the following heuristic for planar Euclidean instances of the traveling salesman problem (TSP): select a subset of the edges which induces a planar graph, and solve either the TSP or its graphical relaxation on that graph. In this paper, we give
Pearson, N   +3 more
core   +1 more source

On Longest Cycles in Essentially 4-Connected Planar Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2016
A planar 3-connected graph G is essentially 4-connected if, for any 3-separator S of G, one component of the graph obtained from G by removing S is a single vertex.
Fabrici Igor   +2 more
doaj   +1 more source

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