Results 41 to 50 of about 892,665 (298)

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

Relaxed DP-Coloring and another Generalization of DP-Coloring on Planar Graphs without 4-Cycles and 7-Cycles

open access: yesDiscussiones Mathematicae Graph Theory, 2023
DP-coloring is generalized via relaxed coloring and variable degeneracy in [P. Sittitrai and K. Nakprasit, Su cient conditions on planar graphs to have a relaxed DP-3-coloring, Graphs Combin. 35 (2019) 837–845], [K.M. Nakprasit and K.
Sribunhung Sarawute   +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

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

Planar Transitive Graphs [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2018
We prove that the first homology group of every planar locally finite transitive graph $G$ is finitely generated as an $\Aut(G)$-module and we prove a similar result for the fundamental group of locally finite planar Cayley graphs. Corollaries of these results include Droms's theorem that planar groups are finitely presented and Dunwoody's theorem that
openaire   +3 more sources

On Pathos Semitotal and Total Block Graph of a Tree [PDF]

open access: yes, 2011
The concept of pathos of a graph G was introduced by Harary [2], as a collection of minimum number of line disjoint open paths whose union is G. The path number of a graph G is the number of paths in pathos.
Muddebihal M. H.
core   +1 more source

3-degenerate induced subgraph of a planar graph [PDF]

open access: yes, 2021
A graph $G$ is $d$-degenerate if every non-null subgraph of $G$ has a vertex of degree at most $d$. We prove that every $n$-vertex planar graph has a $3$-degenerate induced subgraph of order at least $3n/4$.Comment: 28 pages, 12 ...
Oum, Sang-il   +12 more
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

Quasipolynomiality of the Smallest Missing Induced Subgraph

open access: yesJournal of Graph Algorithms and Applications, 2023
We study the problem of finding the smallest graph that does not occur as an induced subgraph of a given graph. This missing induced subgraph has at most logarithmic size and can be found by a brute-force search, in an $n$-vertex graph, in time $n^{O ...
David Eppstein   +2 more
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

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