Zobrazeno 1 - 10
of 36
pro vyhledávání: '"Nasrin Dehgardi"'
Autor:
Nasrin Dehgardi
Publikováno v:
Mathematics Interdisciplinary Research, Vol 9, Iss 4, Pp 373-383 (2024)
Zagreb indices were reformulated in terms of the edge degrees instead of the vertex degrees. For a graph $G$, the first and second reformulated Zagreb indices are defined respectively as:$$EM_1(G)=\sum_{\varepsilon\in E(G)}d^2(\vare
Externí odkaz:
https://doaj.org/article/34dfd5d1622a421dbfa566fe16601b43
Autor:
Nasrin Dehgardi
Publikováno v:
Journal of Mahani Mathematical Research, Vol 13, Iss 2, Pp 547-562 (2024)
For a graph $G$, the third neighborhood degree index of $G$ is defined as: $$ND_3(G)=\sum_{ab\in E(G)}\delta_G(a)\delta_G(b)\Big(\delta_G(a)+\delta_G(b)\Big),$$ where $\delta_G(a)$ represents the sum of degrees of all neighboring vertices of vertex $
Externí odkaz:
https://doaj.org/article/4b6334a9780c462f95948db61391ae16
Publikováno v:
پژوهشهای ریاضی, Vol 6, Iss 4, Pp 501-508 (2020)
Externí odkaz:
https://doaj.org/article/994a4347e5b9435db94406a796a86e14
Autor:
Nasrin Dehgardi, Lutz Volkmann
Publikováno v:
Communications in Combinatorics and Optimization, Vol 5, Iss 2, Pp 139-155 (2020)
Let $G$ be a finite and simple graph with vertex set $V(G)$. A nonnegative signed total Roman dominating function (NNSTRDF) on a graph $G$ is a function $f:V(G)\rightarrow\{-1, 1, 2\}$ satisfying the conditions that (i) $\sum_{x\in N(v)}f(x)\ge 0$
Externí odkaz:
https://doaj.org/article/b1e0f1acd63f4346b8880e2e18b6e108
Publikováno v:
AIMS Mathematics, Vol 5, Iss 6, Pp 5564-5571 (2020)
We investigate some relationships between two vastly studied parameters of a simple graph $G$. These parameters include mixed domination number (denoted by $\gamma_m(G)$) and 2-independence number ($\beta_2(G)$). For a tree $T$, we obtain $\frac{3}{4
Externí odkaz:
https://doaj.org/article/f5afc336f5104a23a72d8cb208cd460e
Publikováno v:
Discrete Dynamics in Nature and Society, Vol 2020 (2020)
For a (molecular) graph G, the first and the second entire Zagreb indices are defined by the formulas M1εG=∑x∈VG∪EGdx2 and M2εG=∑x is either adjacent or incident to ydxdy in which dx represents the degree of a vertex or an edge x. In the cu
Externí odkaz:
https://doaj.org/article/a6026bd22a7c462fa1edcff1b2f2c902
Autor:
Hamideh Aram, Nasrin Dehgardi
Publikováno v:
Communications in Combinatorics and Optimization, Vol 2, Iss 2, Pp 87-98 (2017)
The first general Zagreb index is defined as $M_1^\lambda(G)=\sum_{v\in V(G)}d_{G}(v)^\lambda$ where $\lambda\in \mathbb{R}-\{0,1\}$. The case $\lambda=3$, is called F-index. Similarly, reformulated first general Zagreb index
Externí odkaz:
https://doaj.org/article/eec169ed101946629a7c34c75d13b92d
Publikováno v:
Journal of Chemistry, Vol 2019 (2019)
The third leap Zagreb index is the sum of the products of vertex degrees and second degrees. In this paper, a lower bound on the third leap Zagreb index is established, and the extremal trees achieving this bound are characterized.
Externí odkaz:
https://doaj.org/article/379414543c8b475a9e7a3f9d0ec461d7
Publikováno v:
Mathematics, Vol 7, Iss 2, p 203 (2019)
Let k be a positive integer, and set [ k ] : = { 1 , 2 , … , k } . For a graph G, a k-rainbow dominating function (or kRDF) of G is a mapping f : V ( G ) → 2 [ k ] in such a way that, for any vertex v ∈ V ( G ) with the empty set under f, the c
Externí odkaz:
https://doaj.org/article/7f0e6922348748598632b9d435631a6c
Publikováno v:
Transactions on Combinatorics, Vol 2, Iss 3, Pp 21-32 (2013)
A {em 2-rainbow dominating function} (2RDF) of a graph $G$ is a function $f$ from the vertex set $V(G)$ to the set of all subsets of the set ${1,2}$ such that for any vertex $vin V(G)$ with $f(v)=emptyset$ the condition $bigcup_{uin N(v)}f(u)={1,2}$
Externí odkaz:
https://doaj.org/article/c1d862b6e5de48e6bbef8eba63f6f5ea