Results 31 to 40 of about 18,159 (263)

On Almost-Planar Graphs

open access: yesThe Electronic Journal of Combinatorics, 2018
A nonplanar graph $G$ is called almost-planar if for every edge $e$ of $G$, at least one of $G\backslash e$ and $G/e$ is planar. In 1990, Gubser characterized 3-connected almost-planar graphs in his dissertation. However, his proof is so long that only a small portion of it was published.
Guoli Ding   +2 more
openaire   +3 more sources

Proportional Contact Representations of Planar Graphs

open access: yesJournal of Graph Algorithms and Applications, 2012
We study contact representations for planar graphs, with vertices represented by simple polygons and adjacencies represented by point-contacts or side-contacts between the corresponding polygons.
Md. Jawaherul Alam   +4 more
doaj   +1 more source

Recognizing IC-Planar and NIC-Planar Graphs

open access: yesJournal of Graph Algorithms and Applications, 2018
We prove that triangulated IC-planar graphs and triangulated $K_5$-free or $X4W$-free NIC-planar graphs can be recognized in cubic time. A graph is 1-planar if it can be drawn in the plane with at most one crossing per edge.
Franz Brandenburg
doaj   +1 more source

Cubic planar graphs that cannot be drawn on few lines

open access: yesJournal of Computational Geometry, 2021
For every integer $\ell$, we construct a cubic 3-vertex-connected planar bipartite graph $G$ with $O(\ell^3)$ vertices such that there is no planar straight-line drawing of $G$ whose vertices all lie on $\ell$ lines.
David Eppstein
doaj   +1 more source

Rook-drawings of Plane Graphs

open access: yesJournal of Graph Algorithms and Applications, 2017
We introduce a new type of graph drawing called "rook-drawing". A rook-drawing of a graph $G$ is obtained by placing the $n$ nodes of $G$ on the intersections of a regular grid, such that each row and column of the grid supports exactly one node.
David Auber   +3 more
doaj   +1 more source

On planar hypohamiltonian graphs

open access: yesJournal of Graph Theory, 2010
Summary: We present a planar hypohamiltonian graph on 42 vertices and (as a corollary) a planar hypotraceable graph on 162 vertices, improving the bounds of Zamfirescu and Zamfirescu and show some other consequences. We also settle the open problem whether there exists a positive integer \(N\), such that for every integer \(n\geq N\) there exists a ...
Wiener, Gabor, Araya, Makoto
openaire   +3 more sources

The number of planar graphs and properties of random planar graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2005
We show an asymptotic estimate for the number of labelled planar graphs on $n$ vertices. We also find limit laws for the number of edges, the number of connected components, and other parameters in random planar graphs.
Omer Gimenez, Marc Noy
doaj   +1 more source

Intrapatient tumour heterogeneity and clonal evolution in an autopsy study of metastatic salivary gland cancer

open access: yesMolecular Oncology, EarlyView.
Tumour heterogeneity and clonal evolution of metastatic salivary gland cancer were evaluated in two patients with adenoid carcinoma and one patient with myoepithelial carcinoma. Radiology‐guided autopsy enabled multi‐region sampling (total samples n = 149), followed by whole‐genome sequencing and phylogenetic reconstruction (17 tumour samples, 4–7 per ...
Gerben Lassche   +10 more
wiley   +1 more source

A Note on Universal Point Sets for Planar Graphs

open access: yesJournal of Graph Algorithms and Applications, 2020
We investigate which planar point sets allow simultaneous straight-line embeddings of all planar graphs on a fixed number of vertices. We first show that at least $(1.293-o(1))n$ points are required to find a straight-line drawing of each $n$-vertex ...
Manfred Scheucher   +2 more
doaj   +1 more source

Total Coloring of Dumbbell Maximal Planar Graphs

open access: yesMathematics, 2022
The Total Coloring Conjecture (TCC) states that every simple graph G is totally (Δ+2)-colorable, where Δ denotes the maximum degree of G. In this paper, we prove that TCC holds for dumbbell maximal planar graphs.
Yangyang Zhou   +3 more
doaj   +1 more source

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