مرور Transactions on Combinatorics بر اساس عنوان

در حال نمایش موارد 1 - 20 از 241

  • The $a$-number of jacobians of certain maximal curves 

    Nourozi, vahid؛ Nourozi, vahid؛ Tafazolian, Saeed؛ Tafazolian, Saeed؛ Rahamti, Farhad؛ Rahamti, Farhad (University of Isfahan, 2021-06-01)
    In this paper, we compute a formula for the $a$-number of certain maximal curves given by the equation $y^{q}+y=x^{frac{q+1}{2}}$ over the finite field $mathbb{F}_{q^2}$. The same problem is studied for the maximal curve ...

  • Adjacent vertex distinguishing acyclic edge coloring of the Cartesian product of graphs 

    Mousavi, Fatemeh Sadat؛ Noori, Massomeh (University of Isfahan, 2017-06-01)
    ‎Let $G$ be a graph and $chi^{prime}_{aa}(G)$ denotes the minimum number of colors required for an‎ ‎acyclic edge coloring of $G$ in which no two adjacent vertices are incident to edges colored with the same set of colors‎. ...

  • Annihilating submodule graph for modules 

    Safaeeyan, Saeed (University of Isfahan, 2018-03-01)
    Let $R$ be a commutative ring and $M$ an‎ ‎$R$-module‎. ‎In this article‎, ‎we introduce a new generalization of‎ ‎the annihilating-ideal graph of commutative rings to modules‎. ‎The‎ ‎annihilating submodule graph of $M$‎, ...

  • The annihilator graph of a 0-distributive lattice 

    Bagheri, Saeid؛ Koohi Kerahroodi, Mahtab (University of Isfahan, 2018-09-01)
    ‎‎In this article‎, ‎for a lattice $mathcal L$‎, ‎we define and investigate‎ ‎the annihilator graph $mathfrak {ag} (mathcal L)$ of $mathcal L$ which contains the zero-divisor graph of $mathcal L$ as a subgraph‎. ‎Also‎, ...

  • Approachable‎ ‎ graph (tree) and ‎Its ‎application ‎in hyper (network) 

    Hamidi, Mohammad (University of Isfahan, 2024-09-01)
    A hypertree is a special type of connected hypergraph that removes‎ ‎any‎, ‎its hyperedge then results in a disconnected hypergraph‎. ‎Relation between hypertrees (hypergraphs) and trees (graphs) can be helpful to solve ...

  • Approximate $k$-nearest neighbor graph on moving points 

    Rahmati, Zahed (University of Isfahan, 2023-06-01)
    In this paper, we introduce an approximation for the $k$-nearest neighbor graph ($k$-NNG) on a point set $P$ in $\mathbb{R}^d$. For any given $\varepsilon>0$, we construct a graph, that we call the \emph{approximate $k$-NNG}, ...

  • Bijections for classes of labelled trees 

    Nyariaro, Albert P.؛ Okoth, Isaac (University of Isfahan, 2024-09-01)
    Trees are acyclic connected graphs. Plane trees, $d$-ary trees, binary trees, noncrossing trees and their generalizations, which are families of trees, have been enumerated by many authors using various statistics. These ...

  • Binary sequence/array pairs via diference set pairs: A recursive approach 

    Arasu, K. T.؛ Goyal, Anika؛ Puri, Abhishek (University of Isfahan, 2017-09-01)
    Binary array pairs with optimal/ideal correlation values and their algebraic counterparts textquotedblleft difference set pairstextquotedblright;(DSPs) in abelian groups are studied‎. ‎In addition to generalizing known ...

  • A bound for the locating chromatic number of trees 

    Behtoei, Ali؛ Anbarloei, Mahdi (University of Isfahan, 2015-03-01)
    Let $f$ be a proper $k$-coloring of a connected graph $G$ and $Pi=(V_1,V_2,ldots,V_k)$ be an ordered partition of $V(G)$ into the resulting color classes. For a vertex $v$ of $G$, the color code of $v$ with respect to $Pi$ ...

  • Bounding the domination number of a tree in terms of its annihilation number 

    Dehgardai, Nasrin؛ Norouzian, Sepideh؛ Sheikholeslami, Seyed Mahmoud (University of Isfahan, 2013-03-01)
    A set $S$ of vertices in a graph $G$ is a dominating set if every‎ ‎vertex of $V-S$ is adjacent to some vertex in $S$‎. ‎The domination‎ ‎number $gamma(G)$ is the minimum cardinality of a dominating set‎ ‎in $G$‎. ‎The ...

  • Bounds for metric dimension and defensive $k$-alliance of graphs under deleted lexicographic product 

    Das, Kinkar Chandra؛ Tavakoli, Mostafa (University of Isfahan, 2020-03-01)
    ‎Metric dimension and defensive $k$-alliance number are two distance-based graph invariants‎ ‎which have applications in robot navigation‎, ‎quantitative analysis of secondary RNA structures‎, ‎national defense and ...

  • Bounds for the skew Laplacian (skew adjacency) spectral radius of a digraph 

    Ganie, Hilal A. (University of Isfahan, 2019-06-01)
    ‎‎For a simple connected graph $G$ with $n$ vertices and $m$ edges‎, ‎let $overrightarrow{G}$ be a digraph obtained by giving an arbitrary direction to the edges of $G$‎. ‎In this paper‎, ‎we consider the skew Laplacian/skew ...

  • Broadcast domination in Tori 

    Soh, Kian Wee؛ Koh, Khee-Meng (University of Isfahan, 2015-12-01)
    A broadcast on a graph $G$ is a function $f‎ : ‎V(G) rightarrow {0‎, ‎1,dots‎, ‎diam(G)}$ such that for every vertex $v in V(G)$‎, ‎$f(v) leq e(v)$‎, ‎where $diam(G)$ is the diameter of $G$‎, ‎and $e(v)$ is the ...

  • Cacti with extremal PI Index 

    Wang, Chunxiang؛ Wang, Shaohui؛ Wei, Bing (University of Isfahan, 2016-12-01)
    The vertex PI index $PI(G) = sum_{xy in E(G)} [n_{xy}(x)‎ + ‎n_{xy}(y)]$ is a distance-based molecular structure descriptor‎, ‎where $n_{xy}(x)$ denotes the number of vertices which are closer to the vertex $x$ than to the ...

  • Cayley hypergraph over polygroups 

    Nikkhah, Abolfazl؛ Davvaz, Bijan (University of Isfahan, 2025-03-01)
    Comer introduced a class of hypergroups, using the name of polygroups. He emphasized the importance of polygroups, by analyzing them in connections to graphs, relations, Boolean and cylindric algebras. Indeed, polygroups ...

  • The central vertices and radius of the regular graph of ideals‎ 

    Shaveisi, Farzad (University of Isfahan, 2017-12-01)
    The regular graph of ideals of the commutative ring $R$‎, ‎denoted by ${Gamma_{reg}}(R)$‎, ‎is a graph whose vertex‎ ‎set is the set of all non-trivial ideals of $R$ and two distinct vertices $I$ and $J$ are adjacent if ...

  • Chromatic number and signless Laplacian spectral radius of graphs 

    Oboudi, Mohammad Reza (University of Isfahan, 2022-12-01)
    For any simple graph $G$, the signless Laplacian matrix of $G$ is defined as $D(G)+A(G)$, where $D(G)$ and $A(G)$ are the diagonal matrix of vertex degrees and the adjacency matrix of $G$, respectively. %Let $\chi(G)$ be ...

  • A class of Ramsey-extremal hypergraphs 

    McKay, Brendan D. (University of Isfahan, 2017-09-01)
    In 1991‎, ‎McKay and Radziszowski proved that‎, ‎however each $3$-subset of a $13$-set is assigned one of two colours‎, ‎there is some $4$-subset whose four $3$-subsets have the same colour‎. ‎More than 25 years later‎, ...

  • A classification of finite groups with integral bi-Cayley graphs 

    Arezoomand, Majid؛ Taeri, Bijan (University of Isfahan, 2015-12-01)
    The bi-Cayley graph of a finite group $G$ with respect to a subset $Ssubseteq G$‎, ‎which is denoted by $BCay(G,S)$‎, ‎is the graph with‎ ‎vertex set $Gtimes{1,2}$ and edge set ${{(x,1)‎, ‎(sx,2)}mid xin G‎, ‎ sin S}$‎. ...

  • A closed formula for the number of inequivalent ordered integer quadrilaterals with fixed perimeter 

    Sadek, Bouroubi (University of Isfahan, 2024-12-01)
    Given an integer $n\geq4$, how many inequivalent quadrilaterals with ordered integer sides and perimeter $n$ are there? Denoting such number by $Q(n)$, the answer is given by the following closed formula:\[Q(n)=\left\{ ...