共查询到19条相似文献,搜索用时 78 毫秒
1.
图带宽和与其对偶超图带宽和的关系 总被引:1,自引:0,他引:1
设H=(E1,E2,…,Em)是集合X上的一个超图,一个1-1映射f:X→{1,2,…,|X|}称为H的一个标号,对H的任一标号f,BS(H,f)=∑(E∈H)max{|f(u)-f(v)|;u,v∈E}称为超图H的关于标号f的带宽和BS(H)=min{BS(H,f)|f是超图H的标号|}称为H的带宽和.论文研究图带宽和与其对偶超图的带宽和这两个参数间的关系. 相似文献
2.
鄢仁政 《纯粹数学与应用数学》2014,(1):40-44
划分问题因其在多个领域的重要应用一直是图论的研究热点.利用张量的特征值研究超图的划分与奇划分,并结合边割的界给出最大奇割、平均最小割、等周数等超图拓扑指标的界.当k取2时,这些结果与对应的图谱理论中的经典结论一致,因此可视为这些结论在超图的推广. 相似文献
3.
苗正科 《数学物理学报(A辑)》2004,24(3):381-384
设H是一个超图, 用H\+*和L(H)分别表示H的对偶超图和线图. 定义H的邻接图是由L(H\+*)和H的所有环组成的图, 记作G\-H. 若G\-H是本原的, 则称H是本原的, 并称γ(G\-H)为H的指数. 该文得到了所有n阶本原简单超图以及所有秩不小于3的n阶本原简单超图的指数集, 并分别刻划了其极超图. 相似文献
4.
本文得到了无标号真严格(d)-连通无圈超图的计数公式,并得到了无标号真严格(d)-连通同胚k不可约无圈超图的计数公式. 相似文献
6.
研究了一般的标号严格(d)-连通无圈超图的计数,得到了n阶标号严格(d)-连通无圈超图的计数公式. 相似文献
7.
给定r-图F,称一个r-图G是F-饱和的,如果G不包含F,但是对于每条满足e∈E((G))的r-边e,G添加该边后会包含F,其中(G)表示G的补图.r-图F的饱和数,记为satr(n,F),指的是n个顶点的F-饱和r-图的最小边数.令Srl,m为一个有l+m个顶点的r-图,其边集合由所有与某固定l-集合交集非空的边组成... 相似文献
8.
9.
10.
文[1]给出了下面的定理: 设A,B为两个n×n(n>1)阶正定厄米特矩阵;μ_1,…μ_4;ν_1,…ν_n分别为A,B的特征值, 相似文献
11.
The aim of this paper is to generalize some concepts and recent results of the algebraic graph theory in order to investigate and describe, by algebraic methods, the properties of some combinatorial structures. Here we introduce a version of "Laplacian matrix" of a hypergraph and we obtain several spectral-like results on its metric parameters, such as the diameter, mean distance, excess, bandwidth and cutsets. 相似文献
12.
13.
Enumeration of Maximum Acyclic Hypergraphs 总被引:1,自引:0,他引:1
Jian-fang Wang Hai-zhu LiInstitute of Applied Mathematics Academy of Mathematics System Sciences Chinese Academy of Sciences Beijing China 《应用数学学报(英文版)》2002,18(2):215-218
Abstract Acyclic hypergraphs are analogues of forests in graphs.They are very useful in the design ofdatabases. In this article,the maximum size of an acvclic hypergraph is determined and the number of maximumγ-uniform acyclic hypergraphs of order n is shown to be (_(r-1)~n)(n(r-1)-r~2 2r)~(n-r-1). 相似文献
14.
15.
The purpose of this paper is the study of hypergroups associated with hypergraphs. In this regards, we construct a ρ-hypergroup by means a given hypergraph by defining a special relation ρ, and then we investigate some related properties. Further, we introduce a special product of ρ-hypergroups. Also, we bridge between subhypergraphs and subhypergroups. Finally, the fundamental relation of a ρ-hypergroup is studied. 相似文献
16.
17.
18.
G-函数与分块阵的特征值分布 总被引:1,自引:1,他引:0
利用由Nowosad和Hoffman提出的G-函数概念来刻划分块阵的特征值分布,对块对角占代性进行了G-函数推广,并研究它们的本质联系,获得了分块阵特征值若干包含域,以及M矩阵的充分条件.所得结果较已有结果,明显具有一般性. 相似文献
19.
Eigenvalues and invariants of tensors 总被引:3,自引:0,他引:3
Liqun Qi 《Journal of Mathematical Analysis and Applications》2007,325(2):1363-1377
A tensor is represented by a supermatrix under a co-ordinate system. In this paper, we define E-eigenvalues and E-eigenvectors for tensors and supermatrices. By the resultant theory, we define the E-characteristic polynomial of a tensor. An E-eigenvalue of a tensor is a root of the E-characteristic polynomial. In the regular case, a complex number is an E-eigenvalue if and only if it is a root of the E-characteristic polynomial. We convert the E-characteristic polynomial of a tensor to a monic polynomial and show that the coefficients of that monic polynomial are invariants of that tensor, i.e., they are invariant under co-ordinate system changes. We call them principal invariants of that tensor. The maximum number of principal invariants of mth order n-dimensional tensors is a function of m and n. We denote it by d(m,n) and show that d(1,n)=1, d(2,n)=n, d(m,2)=m for m?3 and d(m,n)?mn−1+?+m for m,n?3. We also define the rank of a tensor. All real eigenvectors associated with nonzero E-eigenvalues are in a subspace with dimension equal to its rank. 相似文献