مرور Transactions on Combinatorics بر اساس عنوان
در حال نمایش موارد 1 - 20 از 241
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The $a$-number of jacobians of certain maximal curves
(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 ...
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Adjacent vertex distinguishing acyclic edge coloring of the Cartesian product of graphs
(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. ...
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Annihilating submodule graph for modules
(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 $M$, ...
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The annihilator graph of a 0-distributive lattice
(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, ...
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Approachable graph (tree) and Its application in hyper (network)
(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 ...
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Approximate $k$-nearest neighbor graph on moving points
(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}, ...
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Bijections for classes of labelled trees
(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 ...
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Binary sequence/array pairs via diference set pairs: A recursive approach
(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 ...
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A bound for the locating chromatic number of trees
(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 $Pi$ ...
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Bounding the domination number of a tree in terms of its annihilation number
(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 ...
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Bounds for metric dimension and defensive $k$-alliance of graphs under deleted lexicographic product
(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 ...
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Bounds for the skew Laplacian (skew adjacency) spectral radius of a digraph
(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 ...
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Broadcast domination in Tori
(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 ...
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Cacti with extremal PI Index
(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 ...
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Cayley hypergraph over polygroups
(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 ...
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The central vertices and radius of the regular graph of ideals
(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 ...
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Chromatic number and signless Laplacian spectral radius of graphs
(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 ...
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A class of Ramsey-extremal hypergraphs
(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, ...
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A classification of finite groups with integral bi-Cayley graphs
(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 ${{(x,1), (sx,2)}mid xin G, sin S}$. ...
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A closed formula for the number of inequivalent ordered integer quadrilaterals with fixed perimeter
(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\{ ...



