Results 41 to 50 of about 28,401 (120)

Strong Chromatic Index Of Planar Graphs With Large Girth

Discussiones Mathematicae Graph Theory, 2014
Let Δ ≥ 4 be an integer. In this note, we prove that every planar graph with maximum degree Δ and girth at least 1 Δ+46 is strong (2Δ−1)-edgecolorable, that is best possible (in terms of number of colors) as soon as G contains two adjacent vertices of ...
Jennhwa Chang Gerard, Montassier Mickael, Pêche Arnaud, Raspaud André   +3 more
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4-{2-[4-(Dimethylamino)phenyl]ethylidene}benzonitrile

Acta Crystallographica Section E, 2009
In the crystal of the title compound, C17H16N2, molecules are linked by C—H...N hydrogen bonds, forming rings of graph-set motifs R21(6) and R22(10). The title molecule is close to planar, with a dihedral angle between the aromatic rings of 0.6&
Rodolfo Moreno-Fuquen, Richard Dvries, Jahyr Theodoro, Javier Ellena   +3 more
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4-Chloro-2,6-dinitrophenol

Acta Crystallographica Section E, 2010
The aromatic ring of the title compound, C6H3ClN2O5, is almost planar (r.m.s. deviation = 0.007 Å); one nitro substituent is nearly coplanar with the ring [dihedral angle = 3(1)°], whereas the other is twisted [dihedral angle =
Seik Weng Ng
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On the k-Structure Ratio in Planar and Outerplanar Graphs

Discrete Mathematics & Theoretical Computer Science, 2008
A planar k-restricted structure is a simple graph whose blocks are planar and each has at most k vertices. Planar k-restricted structures are used by approximation algorithms for Maximum Weight Planar Subgraph, which motivates this work. The planar k-
Gruia Calinescu, Cristina G. Fernandes
doaj  

Graphs cospectral with a friendship graph or its complement [PDF]

Transactions on Combinatorics, 2013
Let $n$ be any positive integer and let $F_n$ be the friendship (or Dutch windmill) graph with $2n+1$ vertices and $3n$ edges. Here we study graphs with the same adjacency spectrum as the $F_n$.
Alireza Abdollahi, Shahrooz Janbaz, Mohammad Reza Oboudi   +2 more
doaj  

Strictly-convex drawings of 3-connected planar graphs

Journal of Computational Geometry
Strictly-convex straight-line drawings of $3$-connected planar graphs in small area form a classical research topic in Graph Drawing. Currently, the best-known area bound for such drawings of $n$-vertex graphs is $O(n^2) \times O(n^2)$, as shown by ...
Michael Bekos, Martin Gronemann, Fabrizio Montecchiani, Antonios Symvonis   +3 more
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Commuting graphs of gamma rings

Open Mathematics
Let M be a non-commutative gamma ring and ZΓM ${Z}_{{\Gamma}}\left(M\right)$ denote the center of the gamma ring M. The vertices a and b are consecutive if a ≠ b and aαb = bαa for every α ∈ Γ, with vertices taken from the set M−ZΓM $M-{Z}_{{\Gamma ...
Arslan Okan
doaj   +1 more source

Graphs Drawn With Some Vertices per Face: Density and Relationships

IEEE Access
Graph drawing beyond planarity is a research area that has received an increasing attention in the last twenty years, driven by the necessity to mitigate the visual complexity inherent in geometric representations of non-planar graphs. This research area
Carla Binucci, Giuseppe Di Battista, Walter Didimo, Vida Dujmovic, Seok-Hee Hong, Michael Kaufmann, Giuseppe Liotta, Pat Morin, Alessandra Tappini   +8 more
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NP-Completeness Results for Minimum Planar Spanners

Discrete 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  

Image contraction through fuzzy soft outerplanar graph structures. [PDF]

Sci Rep
Jaisankar D, Ramalingam S, Zegeye GB.
europepmc   +1 more source