Volume 3, Issue 2


ارسال های اخیر

  • Leap Zagreb indices of trees and unicyclic graphs 

    Gutman, Ivan؛ Shao, Zehui؛ Li, Zepeng؛ Wang, Shaohui؛ We, Pu (Azarbaijan Shahid Madani University, 2018-12-01)
    By d(v|G) and d_2(v|G) are denoted the number of first and second neighborsof the vertex v of the graph G. The first, second, and third leap Zagreb indicesof G are defined asLM_1(G) = sum_{v in V(G)} d_2(v|G)^2, LM_2(G) = ...

  • Lower bounds on the signed (total) $k$-domination number 

    Volkmann, Lutz (Azarbaijan Shahid Madani University, 2018-12-01)
    Let $G$ be a graph with vertex set $V(G)$. For any integer $kge 1$, a signed (total) $k$-dominating functionis a function $f: V(G) rightarrow { -1, 1}$ satisfying $sum_{xin N[v]}f(x)ge k$ ($sum_{xin N(v)}f(x)ge k$)for every ...

  • Classification of rings with toroidal annihilating-ideal graph 

    Krishnan, Selvakumar؛ P, Subbulakshmi (Azarbaijan Shahid Madani University, 2018-12-01)
    Let R be a non-domain commutative ring with identity and A (R) be theset of non-zero ideals with non-zero annihilators. We call an ideal I of R, anannihilating-ideal if there exists a non-zero ideal J of R such that IJ = ...

  • Some results on a supergraph of the comaximal ideal graph of a commutative ring 

    Visweswaran, S.؛ Parejiya, Jaydeep (Azarbaijan Shahid Madani University, 2018-12-01)
    Let R be a commutative ring with identity such that R admits at least two maximal ideals. In this article, we associate a graph with R whose vertex set is the set of all proper ideals I of R such that I is not contained ...

  • Complexity and approximation ratio of semitotal domination in graphs 

    Shao, Zehui؛ Wu, Pu (Azarbaijan Shahid Madani University, 2018-12-01)
    A set $S subseteq V(G)$ is a semitotal dominating set of a graph $G$ if it is a dominating set of $G$ andevery vertex in $S$ is within distance 2 of another vertex of $S$. Thesemitotal domination number $gamma_{t2}(G)$ is ...

  • On the harmonic index of bicyclic graphs 

    Rasi, Reza (Azarbaijan Shahid Madani University, 2018-12-01)
    The harmonic index of a graph $G$, denoted by $H(G)$, is defined asthe sum of weights $2/[d(u)+d(v)]$ over all edges $uv$ of $G$, where$d(u)$ denotes the degree of a vertex $u$. Hu and Zhou [Y. Hu and X. Zhou, WSEAS Trans. ...