Results 41 to 50 of about 3,509 (176)

Alpha Labeling of Amalgamated Cycles

open access: yesTheory and Applications of Graphs, 2022
A graceful labeling of a bipartite graph is an \a-labeling if it has the property that the labels assigned to the vertices of one stable set of the graph are smaller than the labels assigned to the vertices of the other stable set.
Christian Barrientos
doaj   +1 more source

The Degree-Diameter Problem for Outerplanar Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2017
For positive integers Δ and D we define nΔ,D to be the largest number of vertices in an outerplanar graph of given maximum degree Δ and diameter D. We prove that nΔ,D=ΔD2+O (ΔD2−1)$n_{\Delta ,D} = \Delta ^{{D \over 2}} + O\left( {\Delta ^{{D \over 2 ...
Dankelmann Peter   +2 more
doaj   +1 more source

On the Planarity of Generalized Line Graphs

open access: yesTheory and Applications of Graphs, 2019
One of the most familiar derived graphs is the line graph. The line graph $L(G)$ of a graph $G$ is that graph whose vertices are the edges of $G$ where two vertices of $L(G)$ are adjacent if the corresponding edges are adjacent in~$G$.
Khawlah H. Alhulwah   +2 more
doaj   +1 more source

A characterization of horizontal visibility graphs and combinatorics on words [PDF]

open access: yes, 2010
An Horizontal Visibility Graph (for short, HVG) is defined in association with an ordered set of non-negative reals. HVGs realize a methodology in the analysis of time series, their degree distribution being a good discriminator between randomness and ...
Gutin, Gregory   +2 more
core   +2 more sources

A Note on Edge‐Group Choosability of Planar Graphs without 5‐Cycles

open access: yesJournal of Mathematics, Volume 2020, Issue 1, 2020., 2020
This paper is devoted to a study of the concept of edge‐group choosability of graphs. We say that G is edge‐k‐group choosable if its line graph is k‐group choosable. In this paper, we study an edge‐group choosability version of Vizing conjecture for planar graphs without 5‐cycles and for planar graphs without noninduced 5‐cycles (2010 Mathematics ...
Amir Khamseh, Andrei V. Kelarev
wiley   +1 more source

Connected Graph Searching in Outerplanar Graphs

open access: yesElectronic Notes in Discrete Mathematics, 2005
Search games are a powerfull tool for studying various connectivity parameters of graphs. In the classical search game, we consider an undirected graph G = (V, E) whose edges are initially contaminated. A set of searchers try to clean the graph. At the beginning the graph contains no searchers.
Fedor V. Fomin   +2 more
openaire   +1 more source

Nonplanarity of Iterated Line Graphs

open access: yesJournal of Mathematics, Volume 2020, Issue 1, 2020., 2020
The 1‐crossing index of a graph G is the smallest integer k such that the kth iterated line graph of G has crossing number greater than 1. In this paper, we show that the 1‐crossing index of a graph is either infinite or it is at most 5. Moreover, we give a full characterization of all graphs with respect to their 1‐crossing index.
Jing Wang, Alfred Peris
wiley   +1 more source

A Polynomial-Time Algorithm for Computing the Maximum Common Connected Edge Subgraph of Outerplanar Graphs of Bounded Degree

open access: yesAlgorithms, 2013
The maximum common connected edge subgraph problem is to find a connected graph with the maximum number of edges that is isomorphic to a subgraph of each of the two input graphs, where it has applications in pattern recognition and chemistry.
Takeyuki Tamura, Tatsuya Akutsu
doaj   +1 more source

On Another Class of Strongly Perfect Graphs

open access: yesMathematics, 2022
For a commutative ring R with unity, the associate ring graph, denoted by AG(R), is a simple graph with vertices as nonzero elements of R and two distinct vertices are adjacent if they are associates.
Neha Kansal   +3 more
doaj   +1 more source

Game Chromatic Number of Generalized Petersen Graphs and Jahangir Graphs

open access: yesJournal of Applied Mathematics, Volume 2020, Issue 1, 2020., 2020
Let G = (V, E) be a graph, and two players Alice and Bob alternate turns coloring the vertices of the graph G a proper coloring where no two adjacent vertices are signed with the same color. Alice′s goal is to color the set of vertices using the minimum number of colors, which is called game chromatic number and is denoted by χg(G), while Bob′s goal is
Ramy Shaheen   +3 more
wiley   +1 more source

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