一类双环网络的最优路由算法

设n＞h≥2.双环网络D(n,h)是如下定义的有向图其结点集是Zij={0,1,…,n-1},边集是E={i→i+1(modn),i→i+h(modn)0≤i≤n-1}.设n=qh+r,这里1≤r≤h-1,又设w=[(h-1)/(q+r)]≤h/r.本文提出了D(n,h)中源结点到目的结点的最短路径算法,该算法至多只要两次算术运算和一次比较,并且除了q,h,r和w外,各结点不必预先存储网络中别的信息.     

(n,k)-星图的嵌入连通度

星图S_(n,k)的h-嵌入连通度ζ_h(S_(n,k))(h-嵌入边连通度η_h(S_(n,k)))被定义为顶点子集(边子集)的最小基数,如果存在,将其删除后Sn,k不连通而且连通分支的每个顶点都位于h-维的子网络Sh,l,其中0≤h≤n-2且l≤k.本文研究了星图S_(n,k)的h-嵌入(边)连通度,对于k=2,3和0≤h≤n-2,确定了ζ_h(S_(n,k))和ηh(S_(n,k))的值.     

一类组合和式的性质与应用

设k,n,r∈N,记F（r,n,k）=∑ri=0（-1）r-inr-iik,证明了F（r,n,k）的若干性质,推出了F（r,n,k）的4个递推关系式和5个关系式,得到了公式F（n＋h,n,n＋k）=∑hr=0hr（n＋r）!∑k-ri=0s（ik-r）k＋nk-r＋i和F（n,n＋h,k）=∑nr=1（-1）n-rh-1＋n-rn-rr!∑k-ri=0si（k-r）kk-r＋i（k〉0）,其中（s（ik））=is（ik-1）＋（k＋i-1）si（-k1-1）（1≤i≤k）.还导出了重要公式F（r,n,n）＋F（n-r,n,n）=n!（0≤r≤n）.     

无向双环网络直径的估计

设h,n是满足条件2≤h＜n/2的两个正整数.无向双环网络G(n,1,h)是一个无向图(V,E),这里顶点集V=Zn={0,1,2….,n-1},边集E={i→i 1(modn),i→i-1(modn),i→i h(modn),i→i-h(modn)|i=0,1,2,…,n-1}.双环网络在并行处理的互连网络与局域通信网络的设计中有着重要的应用.利用G(n,1,h)的直径与平行四边形中格点间距离的关系,我们给出了无向双环网络G(n,1,h)新的直径上界估计.设n=qh r这里0≤r＜h.当q＜r时,我们所给出的上界估计比D.Z.Du等人所给的上界估计精确.     

半群T_(n,r)的极大(正则)子半群的完全分类

设S_n和T_n分别是X_n={1, 2,…,n}上的对称群和全变换半群.对1≤r≤n,令T(n,r)={α∈T_n:|im(α)|≤r},则T(n,r)是全变换半群T_n的双边理想.对1≤r≤n-1,考虑半群T_(n,r)=T(n,r)∪S_n,得到了半群T_(n,r)的极大子半群S有且仅有两类:S=T_(n,r)\[τ_i](1≤i≤p=p_r(n))和S=T(n,r)∪G,其中G是群S_n的极大子半群.同时,证明了半群T_(n,r)的极大子半群和极大正则子半群是一致的.所得结果推广了已有的结果.     

h≥n/2的n阶极大临界h-连通图的特征

本文就h≥n/2的情形证明了H.J.krol和H.J.Veldman在文中提出的猜想:对一切h≥3都有,n阶级大临界h连通图中每一点都不得与一个h度顶点相邻,从而其边数为1/2其中k_n=[(h-1)/h]当n≠h mod 2h ((h-1)/h)n-1 当n=h mod 2h     

半群H_n的每个星理想的秩和幂等元秩

设H n是自然序集X n={1,2,3,…,n}(n≥3)上的保降序且保序有限奇异变换半群,记H(n,r)={α∈H n:|Imα|≤r}为半群H n的双边星理想.对1≤r≤n-1,刻划了H(n,r)是由秩为r的幂等元生成的且它的秩和幂等元秩都等于Cr-1n-1.进一步证明了当l=r时,r(H(n,r),H(n,l))=0且当1≤lr时,r(H(n,r),H(n,l))=Cr-1n-1.     

半群PO_n中理想的非群元秩和相关秩

设POn是有限链[n]上的保序部分奇异变换半群.对任意的r(2≤r≤n-1),考虑半群M(n,r)={α∈POn:|Imα|≤r}的非群元秩和非幂等元秩.证明了M(n,r)是由秩为r的元素生成的.确定了当0≤l≤r时,半群M(n,r)关于其理想M(n,l)的相关秩.     

半群W_D(n,r)的非群元秩和相关秩

设自然数n≥3,RCDOn是有限链[n]上的正则保反序且压缩奇异变换半群.对任意的r(1≤r≤n-1),记W_D(n,r)={α∈RCDO_n:|Im(α)|≤r}为半群RCDO_n的双边理想.通过对其非群元和格林关系的分析,分别获得了半群W_D(n,r)的极小非群元生成集、非群元秩和非幂等元秩.进一步确定了当1≤l≤r时,半群W_D(n,r)关于其理想W_D(n,l)的相关秩.     

半群SPK~-(n,r)的秩

设SPS-n是[n]上的严格降序部分变换半群.对n≥5和3≤r≤n-2,证明了半群SPK-(n,r)={α∈SPS-n:︱im(α)︱≤r}是幂等元生成的,且秩和幂等秩都为(r+1)S(n,r+1).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

Features of Women''s language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme