WebGIS的解决方案及开发方法

分析了ＧＩＳ的最新发展技术ＷｅｂＧＩＳ技术的概念,并对传统的ＧＩＳ技术和ＷｅｂＧＩＳ进行了比较,探讨了ＷｅｂＧＩＳ的解决方案,开发模式和使用的关键技术。     

基于ORDB的Web GIS空间数据管理研究

进入２０世纪９０年代以来 ,随着网络技术的发展 ,原来的基于单机模式的ＧＩＳ已经无法满足用户对共享地理信息的需要 ,越来越多的人期通过Ｉｎｔｅｒ ｎｅｔ获取地理信息 ,基于网络的ＧＩＳ顺势而生。由于大多数网络ＧＩＳ的客户端采用了ＷＷＷ协议 ,因此学术界把类似的地理信息系统称为ＷｅｂＧＩＳ。其主要目的就是在网络环境下实现地理信息的存储、处理、分析与显示 ,使用户能通过通用浏览器（ＩＥ或ＮＳ）访问并获取地理信息 ［１］。一、ＷｅｂＧＩＳ的特点和空间数据可视化的过程ＷｅｂＧＩＳ作为当前ＧＩＳ领域的研究热点和未来的发…     

铁路勘测设计一体化与地理信息系统

通过考察我国铁路勘测设计技术现状和存在的问题，分析地理信息系统（ＧＩＳ）与铁路勘测设计的关系，提出了基于ＷｅｂＧＩＳ的铁路勘测设计一体化解决方案，讨论了基于ＷｅｂＧＩＳ的铁路勘测设计系统的体系结构、应用前景和对铁路勘测设计的影响．     

基于Web的全文检索电子图书系统的建立

介绍了一种建立基于Ｗｅｂ的全文检索电子图书系统的方法，讨论了ＷＷＷＳｅｒｖｅｒ与ＳＱＩ．Ｓｅｒｖｅｒ数据库的ＣＧＩ接口，并介绍了以ＷＷＷ技术建立的电子图书系统实例－－家族医生杂志全文检索系统。     

一种基于WebGIS的导航系统的设计与实现

设计并实现了一种基于万维网地理信息系统（ＷｅｂＧＩＳ）的电子导航系统。该系统选用ＭａｐＩｎｆｏ作为ＧＩＳ开发平台,并将最短路径椭圆算法运用到电子导航的路径取当中,由于使用ＧＩＳ技术,系统不仅能方便地以图形方式输出导航路线,而且增添了对地理图形和空间数据进行管理的若干功能。     

GIS应用体系结构发展演化及Web GIS实现方法与应用研究

ＷｅｂＧＩＳ俗称万维网地理信息系统,又有人称它为ＩｎｔｅｒｎｅｔＧＩＳ,是一种基于Ｉｎｔｅｒｎｅｔ／Ｉｎｔｒａｎｅｔ的技术标准和通信协议的网络化地理信息系统,它系ＧＩＳ技术和Ｉｎｔｅｒｎｅｔ／Ｉｎｔｒａｎｅｔ技术相结合的产物。一、ＧＩＳ系统技术应用体系结构的发展演化经过近４０年的发展,ＧＩＳ系统已从原来的带有学术研究性质的应用研究逐步走向服务于企业、服务于管理的社会化应用发展研究,并且已广泛应用于科研教育、社会生产、管理决策等各个层面和领域。与整个计算机技术发展过程相适应。近４０年来,ＧＩＳ系统…     

利用ASP开发基于Intranet的MIS

人类已经进入了信息时代,计算机网络已广泛应用于各行各业。许多企业建立自己的Ｉｎｔｒａｎｅｔ或联入Ｉｎｔｅｒｎｅｔ。当他们将信息纳入到Ｉｎｔｒａｎｅｔ／Ｉｎｔｅｒｎｅｔ的框架之后,面临一个共同的问题：如何通过Ｗｅｂ页面来访问后台数据库中的信息。目前,通过Ｗｅｂ页面来访问后台数据库的方法有多种,例如：ＣＧＩ、ＩＳＡＰＩ、ＪＤＢＣ等。ＡＳＰ（ＡｃｔｉｖｅＳｅｒｖｅｒＰａｇｅｓ）是Ｍｉｃｒｏｓｏ且公司为ⅡＳ３．０以及ＭＳＰｅｒｓｏｎａｌＷｅｂＳｅｒｖｅｒ等Ｗｅｂ服务器开发的动态站点设计技术,它具有动态、…     

基于Browser／Server方式的数据库访问技术

主要论述了基于Ｂｒｏｗｓｅｒ／Ｓｅｒｖｅｒ方式的数据库访问技术,讨论了在Ｗｅｂ上通过ＣＧＩ技术,专用ＡＰＩ技术,ＡＳＰ和ＪＤＢＣ技术访问数据库的几种解决方案,并对它们进行了分析、比较和评述。     

直径为3的GS图

研究了直径为３的ＧＳ图的性质。提出了一个非Ｉ－ＧＳ图的构造方法，并证明了由此方法可构造出无穷多个非Ｉ－ＧＳ图，从而解决了Ｐｈｉｌｉｐ　Ｌａｕｆｅｒ提出的下列两个问题：（１）除了已知的两个非Ｉ－ＧＳ图，是否还有其他非Ｉ－ＧＳ图；（２）非Ｉ－ＧＳ图是否为有限个。     

WWW访问数据库及其在Windows环境下的实现

主要研究了从ＷＷＷ上访问数据库的各种方法,并在Ｗｉｎｄｏｗｓ环境下,以Ｗｅｂｓｉｔｅ１．１作ＷＷＷ服务器,用ＣＧＩ方法实现了对ＭＳＳＱＬＳｅｒｖｅｒ的访问．     

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.     

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     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。