Results 11 to 20 of about 2,700 (119)

Coloring Powers and Girth [PDF]

open access: yesSIAM Journal on Discrete Mathematics, 2016
15 pages, 2 figures, 2 tables; from v1 to v2, one section removed, one theorem ...
Kang, J.R., Kang, J.R., Pirot, F.F.
openaire   +4 more sources

On Hypergraphs of Girth Five [PDF]

open access: yesThe Electronic Journal of Combinatorics, 2003
In this paper, we study $r$-uniform hypergraphs ${\cal H}$ without cycles of length less than five, employing the definition of a hypergraph cycle due to Berge. In particular, for $r = 3$, we show that if ${\cal H}$ has $n$ vertices and a maximum number of edges, then $$|{\cal H}|={\textstyle 1\over6}n^{3/2} + o(n^{3/2}).$$ This also asymptotically ...
Felix Lazebnik, Jacques Verstraëte
openaire   +2 more sources

The 6-girth-thickness of the complete graph

open access: yesAKCE International Journal of Graphs and Combinatorics, 2020
The g-girth-thickness of a graph G is the minimum number of planar subgraphs of girth at least g whose union is G. In this paper, we determine the 6-girth-thickness of the complete graph Kn in almost all cases.
Héctor Castañeda-López   +4 more
doaj   +1 more source

Some bounds on the modified Randic index [PDF]

open access: yesKragujevac Journal of Science, 2015
In this paper, we present some new lower and upper bounds for the modified Randic index in terms of maximum, minimum degree, girth, algebraic connectivity, diameter and average distance.
Mahsa Hemmasi, Ali Iranmanesh
doaj   +1 more source

Equitable Coloring of IC-Planar Graphs with Girth g ≥ 7

open access: yesAxioms, 2023
An equitable k-coloring of a graph G is a proper vertex coloring such that the size of any two color classes differ at most 1. If there is an equitable k-coloring of G, then the graph G is said to be equitably k-colorable.
Danjun Huang, Xianxi Wu
doaj   +1 more source

Radius, girth and minimum degree [PDF]

open access: yesJournal of Graph Theory, 2022
AbstractThe objective of the present paper is to study the maximum radius of a connected graph of order , minimum degree and girth at least . Erdős, Pach, Pollack and Tuza proved that if , that is, the graph is triangle‐free, then , and noted that up to the value of the additive constant, this upper bound is tight.
Vojtech Dvorák   +3 more
openaire   +4 more sources

Constructing Large Girth QC Protograph LDPC Codes Based on PSD-PEG Algorithm

open access: yesIEEE Access, 2017
For a given base graph, the lifted graph can be obtained by a copy-and-permute procedure. If the permutation is cyclic, the lifted graph corresponds to a quasi-cyclic (QC) protograph low-density parity-check (LDPC) code.
Xue-Qin Jiang   +3 more
doaj   +1 more source

Lower Bounds on the Lifting Degree of QC-LDPC Codes by Difference Matrices

open access: yesIEEE Access, 2018
In this paper, we define two “difference matrices” which correspond to an exponent matrix. We present necessary and sufficient conditions for these difference matrices to have quasi-cyclic low-density parity-check codes (QC-LDPC) codes with
Farzane Amirzade, Mohammad-Reza Sadeghi
doaj   +1 more source

A Note on the Girth of (3, 19)-Regular Tanner’s Quasi-Cyclic LDPC Codes

open access: yesIEEE Access, 2021
In this article, we study the cycle structure of (3, 19)-regular Tanner’s quasi-cyclic (QC) LDPC codes with code length $19p$ , where $p$ is a prime and $p\equiv 1~(\bmod ~57)$ , and transform the conditions for the existence of cycles of ...
Manjie Zhou   +4 more
doaj   +1 more source

Of Girths and Brains [PDF]

open access: yesAmerican Journal of Neuroradiology, 2014
It is now official: We Americans are no longer the heaviest in the Western World. This ignominious claim belongs south of the border, to Mexico. The obesity rate of Mexicans (32.8%) has now surpassed that of Americans (31.8%).
openaire   +2 more sources

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