Results 21 to 30 of about 107,869,965 (249)

On (p, 1)-Total Labelling of Some 1-Planar Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this paper, it is proved that the (p, 1)-total labelling number (p ≥ 2) of every 1-planar graph G is at most Δ(G) + 2p − 2 provided that Δ (G) ≥
Niu Bei, Zhang Xin
doaj   +1 more source

Bar 1-Visibility Graphs and their relation to other Nearly Planar Graphs

open access: yesJournal of Graph Algorithms and Applications, 2014
A graph is called a strong (resp. weak) bar 1-visibility graph if its vertices can be represented as horizontal segments (bars) in the plane so that its edges are all (resp.
William Evans   +4 more
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

1-Visibility Representations of 1-Planar Graphs

open access: yesJournal of Graph Algorithms and Applications, 2014
A 1-visibility representation of a graph displays each vertex as a horizontal vertex-segment, called a bar, and each edge as a vertical edge-segment between the segments of the vertices, such that each edge-segment crosses at most one vertex-segment and ...
Franz Brandenburg
doaj   +1 more source

On Aligned Bar 1-Visibility Graphs

open access: yesJournal of Graph Algorithms and Applications, 2017
A graph is called a bar 1-visibility graph if its vertices can be represented as horizontal segments, called bars, and each edge corresponds to a vertical line of sight which can traverse another bar.
Franz Brandenburg   +2 more
doaj   +1 more source

The complexity of two graph orientation problems [PDF]

open access: yes, 2012
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 ElsevierWe consider two orientation problems in a graph, namely the minimization of the sum of all the shortest path ...
Noble, SD   +5 more
core   +1 more source

1-Planarity of Graphs with a Rotation System

open access: yesJournal of Graph Algorithms and Applications, 2015
A graph is 1-planar if it can be drawn in the plane such that each edge is crossed at most once. 1-planarity is known NP-hard, even for graphs of bounded bandwidth, pathwidth, or treewidth, and for near-planar graphs in which an edge is added to a planar
Christopher Auer   +3 more
doaj   +1 more source

Drawing outer-1-planar graphs revisited

open access: yesJournal of Graph Algorithms and Applications, 2022
In a recent article (Auer et al., Algorithmica 2016) it was claimed that every outer-1-planar graph has a planar visibility representation of area $O(n\log n)$.
Therese Biedl
doaj   +1 more source

Non-1-Planarity of Lexicographic Products of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
In this paper, we show the non-1-planarity of the lexicographic product of a theta graph and K2. This result completes the proof of the conjecture that a graph G ◦ K2 is 1-planar if and only if G has no edge belonging to two cycles.
Matsumoto Naoki, Suzuki Yusuke
doaj   +1 more source

Planar Graph Classifier - Class Information

open access: yes, 2022
CSV files associating image files from the Planar Graph Classifier - Generated Graph Images (10.5281/zenodo.6510092) with planarity information.
Hummel, Matthias
core   +1 more source

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