Transactions on Combinatorics最新文献_第4页

On a generalization of Leray simplicial complexes 勒雷简单复形的推广

IF 0.4

Transactions on Combinatorics Pub Date : 2020-03-01 DOI: 10.22108/TOC.2019.119856.1682

S. Yassemi

引用次数: 0

Transitive distance-regular graphs from linear groups $L(3,q)$, $q = 2,3,4,5$ 线性群$L(3,q)$， $q = 2,3,4,5$的传递距离正则图

IF 0.4

Transactions on Combinatorics Pub Date : 2020-03-01 DOI: 10.22108/TOC.2020.116255.1630

Andrea Švob

引用次数: 0

$H$-kernels by walks in subdivision digraph $H$-核在细分有向图中行走

IF 0.4

Transactions on Combinatorics Pub Date : 2020-01-05 DOI: 10.22108/TOC.2020.107875.1529

H. Galeana-Sánchez, R. Rojas-Monroy, Maria Del Rocio Sanchez Lopez, Berta Zavala-Santana

{"title":"$H$-kernels by walks in subdivision digraph","authors":"H. Galeana-Sánchez, R. Rojas-Monroy, Maria Del Rocio Sanchez Lopez, Berta Zavala-Santana","doi":"10.22108/TOC.2020.107875.1529","DOIUrl":"https://doi.org/10.22108/TOC.2020.107875.1529","url":null,"abstract":"Let $H$ be a digraph possibly with loops and $D$ a digraph without loops whose arcs are colored with the vertices of $H$ ($D$ is said to be an $H$-colored digraph)‎. ‎A directed walk $W$ in $D$ is said to be an $H$-walk if and only if the consecutive colors encountered on $W$ form a directed walk in $H$‎. ‎A subset $N$ of the vertices of $D$ is said to be an $H$-kernel by walks if (1) for every pair of different vertices in $N$ there is no $H$-walk between them ($N$ is $H$-independent by walks) and (2) for each vertex $u$ in $V$($D$)-$N$ there exists an $H$-walk from $u$ to $N$ in $D$ ($N$ is $H$-absorbent by walks)‎. ‎Suppose that $D$ is a digraph possibly infinite‎. ‎In this paper we will work with the subdivision digraph $S_H$($D$) of $D$‎, ‎where $S_H$($D$) is an $H$-colored digraph defined as follows‎: ‎$V$($S_H$($D$)) = $V$($D$) $cup$ $A$($D$) and $A$($S_H$($D$)) = {($u$,$a$)‎ : ‎$a$ = ($u$,$v$) $in$ $A$($D$)} $cup$ {($a$,$v$)‎ : ‎$a$ = ($u$,$v$) $in$ $A$($D$)}‎, ‎where ($u$‎, ‎$a$‎, ‎$v$) is an $H$-walk in $S_H$($D$) for every $a$ = ($u$,$v$) in $A$($D$)‎. ‎We will show sufficient conditions on $D$ and on $S_H$($D$) which guarantee the existence or uniqueness of $H$-kernels by walks in $S_H$($D$)‎.","PeriodicalId":43837,"journal":{"name":"Transactions on Combinatorics","volume":"9 1","pages":"61-75"},"PeriodicalIF":0.4,"publicationDate":"2020-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48239239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Nilpotent graphs of skew polynomial rings over non-commutative rings 非交换环上歪斜多项式环的幂零图

IF 0.4

Transactions on Combinatorics Pub Date : 2019-12-31 DOI: 10.22108/TOC.2019.117529.1651

M. Nikmehr

引用次数: 0

Generalized Zagreb index of product graphs 积图的广义萨格勒布指数

IF 0.4

Transactions on Combinatorics Pub Date : 2019-12-01 DOI: 10.22108/TOC.2019.116001.1625

M. Azari

引用次数: 12

Elliptic root systems of type $A_1$, a combinatorial study $A_1$型椭圆根系统的组合研究

IF 0.4

Transactions on Combinatorics Pub Date : 2019-12-01 DOI: 10.22108/TOC.2019.117338.1648

Zahra Kharaghani

引用次数: 0

Some subgroups of $mathbb{F}_q^*$ and explicit factors of $x^{2^nd}-1 in mathbb{F}_q[x]$ $mathbb的一些子群{F}_q^*$和mathbb中$x^｛2^nd｝-1的显式因子{F}_q[x]$

IF 0.4

Transactions on Combinatorics Pub Date : 2019-11-10 DOI: 10.22108/TOC.2019.114742.1612

Manjit Singh

引用次数: 0

Bounds for metric dimension and defensive k-alliance of graphs under deleted lexicographic product 删除字典积下图的度量维数和防御k-联盟的界

IF 0.4

Transactions on Combinatorics Pub Date : 2019-10-12 DOI: 10.22108/TOC.2019.115674.1622

K. Das, M. Tavakoli

引用次数: 2

ON THE FIRST AND SECOND ZAGREB INDICES OF QUASI UNICYCLIC GRAPHS 拟单环图的第一和第二Zagreb指标

IF 0.4

Transactions on Combinatorics Pub Date : 2019-09-01 DOI: 10.22108/TOC.2019.115147.1615

Majid Aghel, A. Erfanian, A. Ashrafi

{"title":"ON THE FIRST AND SECOND ZAGREB INDICES OF QUASI UNICYCLIC GRAPHS","authors":"Majid Aghel, A. Erfanian, A. Ashrafi","doi":"10.22108/TOC.2019.115147.1615","DOIUrl":"https://doi.org/10.22108/TOC.2019.115147.1615","url":null,"abstract":"Let G be a simple graph. The graph G is called a quasi unicyclic graph if there exists a vertex x ∈ V (G) such that G−x is a connected graph with a unique cycle. Moreover, the first and the second Zagreb indices of G denoted by M1(G) and M2(G), are the sum of deg (u) overall vertices u in G and the sum of deg(u) deg(v) of all edges uv of G, respectively. The first and the second Zagreb indices are defined relative to the degree of vertices. In this paper, sharp upper and lower bounds for the first and the second Zagreb indices of quasi unicyclic graphs are given. 1. Basic Definitions The first and the second Zagreb indices are among the oldest topological indices defined in 1972 by Gutman and Trinajstić [9]. These numbers have been used to study the molecular complexity, chirality and some other chemical quantities. The first Zagreb index is defined as the sum of the squares of the degrees of the vertices, i.e. M1 (G) = ∑ u∈V (G) deg (u) and the second Zagreb index is the sum of deg(u)deg(v) overall edges uv of G. This means that M2 (G) = ∑ uv∈E(G) deg(u)deg(v). The first and the second Zagreb indices are defined relative to the degree of vertices, which we summarize them without referring to the degree of vertices. MSC(2010): Primary: 05C35; Secondary: 05C07.","PeriodicalId":43837,"journal":{"name":"Transactions on Combinatorics","volume":"8 1","pages":"29-39"},"PeriodicalIF":0.4,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43417922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

A lower bound on the $k$-conversion number of graphs of maximum degree $k+1$ 最大度图$k+1的$k$-转换数的一个下界$

IF 0.4

Transactions on Combinatorics Pub Date : 2019-09-01 DOI: 10.22108/TOC.2019.112258.1579

C. Mynhardt, Jane L. Wodlinger

引用次数: 1