On multiple colorings of graphs

来源 :第六届全国组合数学与图论大会 | 被引量 : 0次 | 上传用户:mater
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Let t be a positive integer and S a set of integers.If for any two elements a and b of S, |a-b| ≥ t, then S is said to be t-separated.For two sets I and J of integers, the distance between I and J, denoted by d(I, J), is defined as min{|i-j|: i ∈ I,j ∈ J}.Let n,t be two positive integers and j1,j2,… ,jm be m nonnegative integers.An n-fold t-separated L(j1,j2,… ,jm)-labeling of a graph G is an assignment f of sets of nonnegative integers of order n to the vertices of G such that the following two conditions are satisfied: (1) for any vertex v, f(v) is t-separated; (2) for any two vertices u and v,if dG(u, v) =i (i ∈ {1, 2,…, m}), then d(f(u)-f(v)) ≥ ji, where dG(u, v) is the length (number of edges) of a shortest path between u and v in G.Integers assigned to vertices by f are called labels.The difference between the maximum and minimum labels used by f is called the span of f.The n-fold t-separated L(j1,j2,… ,jm)-labeling number of G, denoted by λnt(j1,j2,… ,jm)(G), is defined as the minimum span over all n-fold t-separated L(j1, j2,…, jm)-labelings of G.
其他文献
本刊讯(记者 武增新)近日,生态环境部、农业农村部在京联合召开推进打赢净土保卫战和农业农村污染治理攻坚战视频会议.生态环境部部长黄润秋、农业农村部副部长张桃林出席会
期刊
In this talk, we will introduce some results on the eigenvalues of distance matrix,such as, sharp upper and lower bounds on the distance spectral radius, which
会议
本刊讯 (记者 秦保宁)近日,国家发展改革委联合有关部门、国家数字经济创新发展试验区、媒体单位,以及互联网平台、行业龙头企业、金融机构、科研院所、行业协会等145家单位,
期刊
一、前言关于混凝土收缩和徐变引起的预应力损失,我国现行《铁路工程技术规范·第二篇桥涵》一直沿用苏联五十年代的计算方法。在使用过程中,国内外都有过一些异议,如乌里茨
会议
本会同意商业厅关于第四个棉布計划供应年度(1957年9月至1958年8月)供应問題的报告,現轉发給你們,希即研究貫彻执行。第四个棉布計划供应年度供应城乡人民棉布数量不仅將比
本刊讯(记者 樊俊)近日,财政部副部长、党组成员许宏才出席国务院政策例行吹风会,介绍2019年落实重大政策措施真抓实干成效明显地方予以督查激励的有关情况,并回答记者提问.r
期刊
An old problem of Linial and Wilf asks for the graphs with n vertices and m edges which maximize the number of proper q-colorings on vertices.Loh, Pikhurko and
会议
A path covering of a graph G is a set of vertex disjoint paths of G containing all the vertices of G.The path covering number of G, denoted by P(G), is the mini
会议
根据政务院财政经济委员会关于税制若干修正及实行日期的通告中规定:工业从产制、批发到零售交纳三道营业税;商业贩卖从批民到零售交纳两道营业税的总原则,关于工商业税各项