Results 31 to 40 of about 197 (156)

The Strong 3-Rainbow Index of Graphs Containing Three Cycles [PDF]

open access: yes, 2023
The concept of a strong k-rainbow index is a generalization of a strong rainbow connection number, which has an interesting application in security systems in a communication network.
Zata Yumni Awanis
core   +1 more source

The bipartite Laplacian matrix of a nonsingular tree

open access: yesSpecial Matrices, 2023
For a bipartite graph, the complete adjacency matrix is not necessary to display its adjacency information. In 1985, Godsil used a smaller size matrix to represent this, known as the bipartite adjacency matrix.
Bapat Ravindra B.   +2 more
doaj   +1 more source

Use of a Cytobrush for Sampling the Ear Canal of Dogs With Otitis Externa

open access: yesVeterinary Dermatology, Volume 37, Issue 2, Page 227-235, April 2026.
Cytological examination of the ear canal is essential for evaluating dogs with otitis externa (OE). The conventional sampling method uses a swab. However, the cytobrush (gynaecological cervical brush), already used for cytological collection from other anatomical sites, has not been adequately investigated for this purpose in dogs with OE.
Nicoly Radaeli Atanasio   +3 more
wiley   +1 more source

The Product Connectivity Banhatti Index of A Graph

open access: yesDiscussiones Mathematicae Graph Theory, 2019
Let G = (V, E) be a connected graph with vertex set V (G) and edge set E(G). The product connectivity Banhatti index of a graph G is defined as, PB(G)=∑ue1dG(u)dG(e)$PB(G) = \sum\nolimits_{ue} {{1 \over {\sqrt {{d_G}(u){d_G}(e)} }}}$ where ue means that ...
Kulli V.R.   +2 more
doaj   +1 more source

New Sharp Extremal Bounds for the Randić Index of Trees With Prescribed Roman Domination Number

open access: yesDiscrete Dynamics in Nature and Society, Volume 2026, Issue 1, 2026.
The Randić index is a classical degree‐based topological index that captures branching features of a graph and has broad applications in chemical graph theory and related network models. Roman domination is a defense‐inspired covering concept in which vertices are assigned protective labels so that every unprotected vertex is adjacent to a strongly ...
Waqar Ali   +4 more
wiley   +1 more source

Trees with Unique Least Central Subtrees

open access: yesDiscussiones Mathematicae Graph Theory, 2018
A subtree S of a tree T is a central subtree of T if S has the minimum eccentricity in the join-semilattice of all subtrees of T. Among all subtrees lying in the join-semilattice center, the subtree with minimal size is called the least central subtree ...
Kang Liying, Shan Erfang
doaj   +1 more source

Contraharmonic Index: Extremal Results for Unicyclic Graphs and Bounds for General Graphs

open access: yesJournal of Mathematics, Volume 2026, Issue 1, 2026.
Let G be a graph with edge set E(G). The degree of a vertex w in G is denoted by dw. The contraharmonic index of G is defined as CHG=∑uv∈EGdu+dv−1du2+dv2. In this paper, we investigate several properties of the contraharmonic index, including extremal results for unicyclic graphs of a given order, as well as bounds and the effects of an edge removal in
Abdulaziz Mutlaq Alotaibi   +2 more
wiley   +1 more source

A Note on the Interval Function of a Disconnected Graph

open access: yesDiscussiones Mathematicae Graph Theory, 2018
In this note we extend the Mulder-Nebeský characterization of the interval function of a connected graph to the disconnected case. One axiom needs to be adapted, but also a new axiom is needed in addition.
Changat Manoj   +3 more
doaj   +1 more source

Further generalization of symmetric multiplicity theory to the geometric case over a field

open access: yesSpecial Matrices, 2021
Using the recent geometric Parter-Wiener, etc. theorem and related results, it is shown that much of the multiplicity theory developed for real symmetric matrices associated with paths and generalized stars remains valid for combinatorially symmetric ...
Cinzori Isaac   +3 more
doaj   +1 more source

Affine Semigroups Without Consecutive Small Elements

open access: yesJournal of Mathematics, Volume 2026, Issue 1, 2026.
An A‐semigroup is a numerical semigroup without consecutive small elements. This work generalizes this concept to finite‐complement submonoids of an affine cone C. We develop algorithmic procedures to compute all A‐semigroups with a given Frobenius element (denoted by Af) and with fixed Frobenius element and multiplicity.
J. C. Rosales   +3 more
wiley   +1 more source

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