Bubble-sort网络的二部泛连通度

本文证明了:对于Bubble-sort网络Bn,中任意两点u和v,存在一条长为l的uv路,路长l满足dBn(u,v)+2≤l≤n!-1且2|(l-dBn(u,v))。这个结果改进了已知结果。     

完全对换网络的限制连通度

完全对换网络是基于 Cayley 图模型的一类重要互连网络. 一个图 G 的 k-限制点(边)连通度是使得 G-F 不连通且每个分支至少有 k 个顶点的最小点(边)子集 F 的基数, 记作 \kappa_{k}(\lambda_{k}). 它是衡量网络可靠性的重要参数之一, 也是图的容错性的一种精化了的度量. 一般地, 网络的 k-限制点(边)连通度越大, 它的连通性就越好. 证明了完全对换网络 CT_{n} 的 2-限制点(边)连通度和 3-限制点(边)连通度, 具体来说: 当 n\geq4 时, \kappa_{2}(CT_{n})=n(n-1)-2, \kappa_{3}(CT_{n})=\frac{3n(n-1)}{2}-6; 当 n\geq3 时, \lambda_{2}(CT_{n})=n(n-1)-2, \lambda_{3}(CT_{n})=\frac{3n(n-1)}{2}-4.     

模糊连通度与模糊核度

本文给出了衡量模糊连通性的三个工量：模糊连通度，模糊边连通度与模糊核度及其相关的性质。与普通图连通性的分析相比较，由于考虑了模糊性，这三个量能更好，更深入地刻划出不同的图在连通性方面的微妙差异。     

最大边连通和super-边连通超图的充分条件

设H是连通超图。若超图H的边连通度等于其最小度,则称H是最大边连通的。若超图H的每个最小边割总是由关联于某个最小度顶点的边集所构成,则称H是super-边连通的。首先给出一致线性超图是最大边连通超图的度序列条件。其次,给出一致线性超图是super-边连通超图的度条件。这些结果分别推广了Dankelmann和Volkmann（1997）以及Hellwig和Volkmann（2005）在图上的相关结论。     

关于Mbius立方体网格的连通度(英文)

图的连通度、超连通性和限制连通度是度量互连网络容错性的重要参数 .该文考虑n维M bius立方体网络MQn,证明了它的点和边连通度都为n ,当n是任何正整数时它是超连通的 ,当n≠ 2时它是超边连通的 ,当n≥ 3时它的限制点连通度和当n≥ 2时的限制边连通度都为 2n- 2 .     

关于循环有向图的强连通度

本文定义的循环有向图D(n;S)在分布式环形计算机互连网络设计中被广泛运用。本文证明了D(n;S)的强连通度k>2/3|S|。     

对换网络和乘积循环网络的超连通性

本文证明了对换网络和乘积循环网络是超连通的。     

复合图及其连通度和临界度

本文确定了H(G)的点-连通度及H(G)关于点-连通度的临界度;确确定了H(G)的边-连通度及某种H(G)关于边-连通度的临界度。     

上连通和超连通三次点传递图

图G称为上连通的,若对每个最小割集C,G-C有孤立点,G称为超连通的,若对每个最小割集C,G-C恰有两个连通分支,且其中之一为弧立点,本文刻划了上连通和超连通三次点传递图。     

循环圈的连通度

设G＝C_n（i₁,i₂,…,i_r）是连通循环圈,且k（G）＜δ（G）．本文得到了其连通度的明确表达式κ(G)=min{m|M(n/m,K)|:m是n的真因子,且|M(n/m,K)|相似文献   

Super Connectivity and Super Edge Connectivity of the Mycielskian of a Graph

Mycielski introduced a new graph transformation μ(G) for graph G, which is called the Mycielskian of G. A graph G is super connected or simply super-κ (resp. super edge connected or super-λ), if every minimum vertex cut (resp. minimum edge cut) isolates a vertex of G. In this paper, we show that for a connected graph G with |V(G)| ≥ 2, μ(G) is super-κ if and only if δ(G) < 2κ(G), and μ(G) is super-λ if and only if G\ncong K₂{G\ncong K_2}.     

二元图的最佳连通性

本文介绍二元图的最佳连通性问题，给出了有关最佳连通性的若干结果；并就一般情形，给出了二元图最佳连通性问题的解．     

Flexible Graph Connectivity

Mathematical Programming - We introduce and study the problem Flexible Graph Connectivity, which in contrast to many classical connectivity problems features a non-uniform failure model. We...     

Bubble-sort图和Modified Bubble-sort图的自同构群

Bubble-Sort图和Modified Bubble-Sort图是两类特殊的Cayley图,由于其在网络构建中的应用而受到广泛关注.本文完全确定了这两类图的自同构群.     

Random Graph Coverings I: General Theory and Graph Connectivity

In this paper we describe a simple model for random graphs that have an n-fold covering map onto a fixed finite base graph. Roughly, given a base graph G and an integer n, we form a random graph by replacing each vertex of G by a set of n vertices, and joining these sets by random matchings whenever the corresponding vertices are adjacent in G. The resulting graph covers the original graph in the sense that the two are locally isomorphic. We suggest possible applications of the model, such as constructing graphs with extremal properties in a more controlled fashion than offered by the standard random models, and also "randomizing" given graphs. The main specific result that we prove here (Theorem 1) is that if is the smallest vertex degree in G, then almost all n-covers of G are -connected. In subsequent papers we will address other graph properties, such as girth, expansion and chromatic number. Received June 21, 1999/Revised November 16, 2000 RID="*" ID="*" Work supported in part by grants from the Israel Academy of Aciences and the Binational Israel-US Science Foundation.     

Graph Connectivity After Path Removal

Let G be a graph and u, v be two distinct vertices of G. A u—v path P is called nonseparating if G—V(P) is connected. The purpose of this paper is to study the number of nonseparating u—v path for two arbitrary vertices u and v of a given graph. For a positive integer k, we will show that there is a minimum integer (k) so that if G is an (k)-connected graph and u and v are two arbitrary vertices in G, then there exist k vertex disjoint paths P ₁[u,v], P ₂[u,v], . . ., P _k [u,v], such that G—V (P _i [u,v]) is connected for every i (i = 1, 2, ..., k). In fact, we will prove that (k) 22k+2. It is known that (1) = 3.. A result of Tutte showed that (2) = 3. We show that (3) = 6. In addition, we prove that if G is a 5-connected graph, then for every pair of vertices u and v there exists a path P[u, v] such that G—V(P[u, v]) is 2-connected.* Supported by NSF grant No. DMS-0070059 Supported by ONR grant N00014-97-1-0499 Supported by NSF grant No. 9531824     

Super Connectivity of Line Graphs and Digraphs

The h-super connectivity κh and the h-super edge-connectivity λh are more refined network reliability indices than the conneetivity and the edge-connectivity. This paper shows that for a connected balanced digraph D and its line digraph L, if D is optimally super edge-connected, then κ1（L） = 2λ1 （D）, and that for a connected graph G and its line graph L, if one of κ1 （L） and λ（G） exists, then κ1（L） = λ2（G）. This paper determines that κ1（B（d, n） is equal to 4d- 8 for n = 2 and d ≥ 4, and to 4d-4 for n ≥ 3 and d ≥ 3, and that κ1（K（d, n）） is equal to 4d- 4 for d 〉 2 and n ≥ 2 except K（2, 2）. It then follows that B（d,n） and K（d, n） are both super connected for any d ≥ 2 and n ≥ 1.     

无向Kautz图的超级限制边连通性

限制边连通度作为边连通度的推广,是计算机互连网络可靠性的一个重要度量.Superλ-′是比限制边连通度更精确的一个网络可靠性指标.一个图是Superλ-′的,如果它的任一最小限制边割都孤立一条有最小边度的边.本文考虑一类重要的网络模型-无向K autz图UK(d,n)的限制边连通度λ,′证明了当d 3,n 2时,λ(′UK(d,n))=4d-4,并进一步指出此时的UK(d,n)是Superλ-′的.     

The Maximum Genus of a Graph with Given Diameter and Connectivity

In this paper, we first review some of the known results about the maximum genus of a graph with given diameter or (and) connectivity. Then we prove that a 3-connected diameter 4 multigraph has Betti deficiency at most 2. Furthermore, we show this upper bound is sharp.     

无限循环图的超边连通性(英文)

本文证明了 ,在一切具有有限跃度序列的无限循环图中 ,只有C( 1 ) ,C( 1 ,2 )和C( 1 ,2 ,3)不是超边连通的 ,而且C( 1 )和C( 1 ,2 )是其中仅有的两个非最大边连通图 .