Results 61 to 70 of about 1,056 (209)

Monitoring maximal outerplanar graphs [PDF]

open access: yesElectronic Notes in Discrete Mathematics, 2014
In this paper we define a new concept of monitoring the elements of triangulation graphs by faces. Furthermore, we analyze this, and other monitoring concepts (by vertices and by edges), from a combinatorial point of view, on maximal outerplanar graphs.
Gregorio Hernández-Peñalver   +1 more
openaire   +3 more sources

Small Area Drawings of Outerplanar Graphs

open access: yes, 2006
We show three linear time algorithms for constructing planar straight-line grid drawings of outerplanar graphs. The first and the second algorithm are for balanced outerplanar graphs. Both require linear area. The drawings produced by the first algorithm
Frati, Fabrizio   +3 more
core   +1 more source

Every Property of Outerplanar Graphs is Testable [PDF]

open access: yes, 2016
A D-disc around a vertex v of a graph G=(V,E) is the subgraph induced by all vertices of distance at most D from v. We show that the structure of an outerplanar graph on n vertices is determined, up to modification (insertion or deletion) of at most ...
Newman, Ilan   +2 more
core   +1 more source

Vertex Colorings without Rainbow Subgraphs

open access: yesDiscussiones Mathematicae Graph Theory, 2016
Given a coloring of the vertices of a graph G, we say a subgraph is rainbow if its vertices receive distinct colors. For a graph F, we define the F-upper chromatic number of G as the maximum number of colors that can be used to color the vertices of G ...
Goddard Wayne, Xu Honghai
doaj   +1 more source

Nilpotent graphs with crosscap at most two

open access: yesAKCE International Journal of Graphs and Combinatorics, 2018
Let R be a commutative ring with identity. The nilpotent graph of R, denoted by Γ N ( R ) , is a graph with vertex set Z N ( R ) ∗ , and two vertices x and y are adjacent if and only if x y is nilpotent, where Z N ( R ) = { x ∈ R : x y is nilpotent, for ...
A. Mallika, R. Kala
doaj   +1 more source

A Note on the Fair Domination Number in Outerplanar Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2020
For k ≥ 1, a k-fair dominating set (or just kFD-set), in a graph G is a dominating set S such that |N(v) ∩ S| = k for every vertex v ∈ V − S. The k-fair domination number of G, denoted by fdk(G), is the minimum cardinality of a kFD-set. A fair dominating
Hajian Majid, Rad Nader Jafari
doaj   +1 more source

On Endomorphism Universality of Sparse Graph Classes

open access: yesJournal of Graph Theory, Volume 110, Issue 2, Page 223-244, October 2025.
ABSTRACT We show that every commutative idempotent monoid (a.k.a. lattice) is the endomorphism monoid of a subcubic graph. This solves a problem of Babai and Pultr and the degree bound is best‐possible. On the other hand, we show that no class excluding a minor can have all commutative idempotent monoids among its endomorphism monoids. As a by‐product,
Kolja Knauer, Gil Puig i Surroca
wiley   +1 more source

On Vertices Enforcing a Hamiltonian Cycle

open access: yesDiscussiones Mathematicae Graph Theory, 2013
A nonempty vertex set X ⊆ V (G) of a hamiltonian graph G is called an H-force set of G if every X-cycle of G (i.e. a cycle of G containing all vertices of X) is hamiltonian.
Fabrici Igor   +2 more
doaj   +1 more source

Tight Distance Query Reconstruction for Trees and Graphs Without Long Induced Cycles

open access: yesRandom Structures &Algorithms, Volume 66, Issue 4, July 2025.
ABSTRACT Given access to the vertex set V$$ V $$ of a connected graph G=(V,E)$$ G=\left(V,E\right) $$ and an oracle that given two vertices u,v∈V$$ u,v\in V $$, returns the shortest path distance between u$$ u $$ and v$$ v $$, how many queries are needed to reconstruct E$$ E $$?
Paul Bastide, Carla Groenland
wiley   +1 more source

Algorithm-based radio labeling for optimal channel assignment in outerplanar graphs

open access: yesFrontiers in Computer Science
IntroductionRadio labeling of graphs extends the channel assignment problem by assigning non-negative integers to vertices of a connected graph G such that |h(℘)−h(𝓆)|≥diam(ℊ)+1−d(℘, 𝓆).
Baskar Mari, Ravi Sankar Jeyaraj
doaj   +1 more source

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