由谱半径给树排序

设△（T）和λ1（T）分别表示树T的最大度和谱半径,Tn表示有n个点的树且Tn^（△）=（T∈Tn｜△（T）=△},文章根据树的谱半径给Tn^n-6（n≥18）中的树进行了排序并将结果扩大到第78棵树。     

Tree enumeration modulo a consensus

The number of trees withn labeled terminal vertices grows too rapidly withn to permit exhaustive searches for Steiner trees or other kinds of optima in cladistics and related areas Often, however, structured constraints are known and may be imposed on the set of trees to be scanned These constraints may be formulated in terms of a consensus among the trees to be searched We calculate the reduction in the number of trees to be enumerated as a function of properties of the imposed consensusThis work was supported in part by the Natural Sciences and Engineering Research Council of Canada through operating grant A8867 to D Sankoff and infrastructure grant A3092 to D Sankoff, R J Cedergren and G Lapalme We are grateful to William H E Day for much encouragement and many helpful suggestions     

A RELATION BETWEEN THE MATCHING NUMBER AND LAPLACIAN SPECTRUM OF A TREE

Let T be a tree with matching number μ(T). In this paper we obtain the following result: If T has no perfect matchings, thenμ(T) is a lower bound for the number of nonzero Laplacian eigenvalues of T which are smaller than 2.     

线性方程组分级行处理法贪心方法

给出了在分布式存储的MIMD树机模型上求解任意相容性线性方程组的分级行处理法贪心方法,证明算法收敛并分析算法的通信复杂度。     

XML的DOM树结构在WEB挖掘中的应用

面对飞速发展的信息时代,WEB数据的挖掘日益重要,而传统的搜索引擎难以胜任对数据的挖掘处理。基于XML良好的结构性和层次性,提出了利用DOM树进行WEB挖掘的方法。首先利用Tidy工具库将WEB数据转换成良好结构的XML文件,简化生成DOM树,然后通过遍历解析XML的DOM树结构,提取需要的WEB信息,实现对WEB数据挖掘。实验表明,该方法能够方便地对数据进行结构化存储和信息处理。     

绿化与建筑节能

根据绿化对改善建筑微气候的作用,分析了几种绿化措施对建筑热环境的影响,得出结论:绿化可以大大改善建筑室内热环境,节约能源,具有美化城市及改善城市生态环境的作用。     

《数据结构》辅助教学系统的设计与应用

本文讨论《数据结构》计算机辅助教学系统.该系统利用图形技术使抽象的问题具体化、形象化,从而进一步发挥计算机在教学中的巨大作用.     

TREE DECOMPOSITIONS OF MULTIGRAPHS

1.IntroductionInthispaperweconsideronlyfiniteundirectedlooplessgraphs.ForasubgraphHofG,E(H)andP(H)denotethenumberofedgesandthenUmberofcyclesinHrespectively.GiventwodisjointsubsetsXandYofV(G),wewriteEG(X,Y)={acEE(G)IxEX,y6Y}.IfTisatreeinGande=acEG--E(T)with{u,v}CV(T),thenT econtainsauniquecycle.WedenotethiscyclebyC(T,e).Aforestiscalledak-tree-forestifitconsistsofexactlykpairwisedisjointtrees.ForagraphG,ifE(G)canbepartitionedilltoseveralpairwisedisjointsetsas{EI,EZ,...,EI}such…     

一类树族的伴随多项式及其恒等式

本文主要研究了一类树族伴随多项式的规律，给出并证明了树族T（1，1，…1，m）的伴随多项式的计算公式，从而推广了文献[4]的主要结果。     

截干对叶用银杏生长及树形的影响

对叶用银杏大指品种１年生、２年生和３年生实生苗分别以不同留桩高度截干（或抹顶芽）处理，并对截干后当年的生长及树形指标进行调查。结果表明：（１）截干能矮化树体，扩大冠幅，减少光秃带距，加大部分处理树冠总体积；（２）截干能增加部分处理枝条数量及枝条总长；（３）对当年叶产量影响最大的指标分别为地径、长枝数、长枝长、高幅比及冠长比。因引截干能促进银杏形成优质叶用树形。