计算机专业毕业设计外文翻译---GIS软件和数据结构 (1)
地理信息系统(名词解释)
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1、地理信息系统(geographic information system , 即gis )——一门集计算机科学、 信息学、地理学等多门科学为一体的新兴学科, 它是在计算机软件和硬件支持下, 运用系 统工程和信息科学的理论,科学管理和综合分析具有空间内涵的地理数据,以提供对规划 、管理、决策和研究所需信息的空间信息系统。
2.栅格——栅格结构是最简单最直接的空间数据结构, 是指将地球表面划分为大小均匀 紧密相邻的网格阵列, 每个网格作为一个象元或象素由行、列定义, 并包含一个代码表示 该象素的属性类型或量值, 或仅仅包括指向其属性记录的指针。
因此, 栅格结构是以规则 的阵列来表示空间地物或现象分布的数据组织,组织中的每个数据表示地物或现象的非几何属性特征。
特点:属性明显, 定位隐含, 即数据直接记录属性本身, 而所在的位置则根据行列号转换为相应的坐标,即定位是根据数据在数据集中的位置得到的,在栅格结构中,点用一个栅格单元表示;线状地物用沿线走向的一组相邻栅格单元表示,每个栅格单元最 多只有两个相邻单元在线上;面或区域用记有区域属性的相邻栅格单元的集合表示,每个 栅格单元可有多于两个的相邻单元同属一个区域。
3.矢量——它假定地理空间是连续, 通过记录坐标的方式尽可能精确地表示点、线、 多边形等地理实体, 坐标空间设为连续, 允许任意位置、长度和面积的精确定义。
对于点实体, 矢量结构中只记录其在特定坐标系下的坐标和属性代码;对于线实体, 用一系列坐标对的连线表示;多边形是指边界完全闭合的空间区域,用一系列坐标对的连线表示。
4. “拓扑”(topology)一词来源于希腊文,它的原意是 “形状的研究”。
拓扑学是 几何学的一个分支,它研究在拓扑变换下能够保持不变的几何属性——拓扑属性(拓扑属 性:一个点在一个弧段的端点, 一个点在一个区域的边界上;非拓扑属性:两点之间的距离, 弧段的长度, 区域的周长、面积) 。
软件工程毕业论文文献翻译中英文对照
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软件工程毕业论文文献翻译中英文对照学生毕业设计(论文)外文译文学生姓名: 学号专业名称:软件工程译文标题(中英文):Qt Creator白皮书(Qt Creator Whitepaper)译文出处:Qt network 指导教师审阅签名: 外文译文正文:Qt Creator白皮书Qt Creator是一个完整的集成开发环境(IDE),用于创建Qt应用程序框架的应用。
Qt是专为应用程序和用户界面,一次开发和部署跨多个桌面和移动操作系统。
本文提供了一个推出的Qt Creator和提供Qt开发人员在应用开发生命周期的特点。
Qt Creator的简介Qt Creator的主要优点之一是它允许一个开发团队共享一个项目不同的开发平台(微软Windows?的Mac OS X?和Linux?)共同为开发和调试工具。
Qt Creator的主要目标是满足Qt开发人员正在寻找简单,易用性,生产力,可扩展性和开放的发展需要,而旨在降低进入新来乍到Qt的屏障。
Qt Creator 的主要功能,让开发商完成以下任务: , 快速,轻松地开始使用Qt应用开发项目向导,快速访问最近的项目和会议。
, 设计Qt物件为基础的应用与集成的编辑器的用户界面,Qt Designer中。
, 开发与应用的先进的C + +代码编辑器,提供新的强大的功能完成的代码片段,重构代码,查看文件的轮廓(即,象征着一个文件层次)。
, 建立,运行和部署Qt项目,目标多个桌面和移动平台,如微软Windows,Mac OS X中,Linux的,诺基亚的MeeGo,和Maemo。
, GNU和CDB使用Qt类结构的认识,增加了图形用户界面的调试器的调试。
, 使用代码分析工具,以检查你的应用程序中的内存管理问题。
, 应用程序部署到移动设备的MeeGo,为Symbian和Maemo设备创建应用程序安装包,可以在Ovi商店和其他渠道发布的。
, 轻松地访问信息集成的上下文敏感的Qt帮助系统。
本科毕业设计(论文)外文资料及译文(模板)
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大连东软信息学院
毕业设计(论文)外文资料及译文
系所:
专业:
班级:
姓名:
学号:
大连东软信息学院
Dalian Neusoft University of Information
外文资料和译文格式要求
一、装订要求
1、外文资料原文(复印或打印)在前、译文在后、最后为指导教师评定成绩。
2、译文必须采用计算机输入、打印。
3、A4幅面打印,于左侧装订。
二、撰写要求
1、外文文献内容与所选课题相关。
2、译文汉字字数不少于4000字。
三、格式要求
1、译文字号:中文小四号宋体,英文小四号“Times New Roman”字型,全文统一,首行缩进2个中文字符,1.5倍行距。
2、译文页码:页码用阿拉伯数字连续编页,字体采用“Times New Roman”字体,字号小五,页底居中。
3、译文页眉:眉体使用单线,页眉说明五号宋体,居中“大连东软信息学院本科毕业设计(论文)译文”。
大连东软信息学院毕业设计(论文)译文
-1-。
计算机专业外文翻译(中英文)---HTTP和Servlet的基础知识
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附录A 译文HTTP和Servlet的基础知识让我们从定义Web应用程序这一章开始。
我们都看到过一般的客户端应用软件,但怎么样才是一个真正的Web应用程序?然而,它可以被定义为一个用于用户接入的运行在服务器上的程序,通过一个简单,一般用途的客户。
今天,最常见的客户端是一种运行在pc机上的网页浏览器或工作站系统,但其他类型的用户正在迅速加入,如无线PDA ,手机,和其他专门设备。
最崇高目标是从你面前的任何类型的设备上获得你所要的信息和服务。
这意味着同样的简单客户端程序必须能够与许多不同的服务器应用通话,以及应用程序必须能够适用于许多不同类型的客户。
为了满足这一需要,必须制定详细的客户端和服务器相互通信的协义。
这正是超文本传输协议( HTTP )的目的。
通信模型所确定的HTTP形式的基础,所有的Web应用程序设计。
基本了解HTTP的关键应用,适合发展中国家的限制范围内的协议,无论哪个服务器端技术的使用。
在本章中,我们看一下最重要的细节的HTTP您需要了解作为一个Web 应用程序开发。
另外一个项目:这本书是用JSP作为服务器端技术。
JSP技术是基于Java Servlet技术。
这两种技术有着大量的术语和概念,所以知道一点servlets将帮助你,即使你开发纯JSP的应用。
要真正理解和使用的全部的JSP ,你需要知道一点servlets 。
因此,我们期待在servlet的基本入在最后一章的这一节。
2.1 HTTP请求/响应模型所有扩展HTTP和基于HTTP协议是基于一个非常简单的通信模式。
其工作原理如下:客户端,通常是一个Web浏览器,发出了一个请求资源的服务器,服务器发回的响应相应的资源(或响应的错误信息,如果它不能处理请求出于某种原因)。
A资源是一些事情的数据,如一个简单的HTML文件逐字返回到浏览器或程序,动态生成的响应。
这种简单的模式意味着三个重要的事实你需要了解:HTTP是一种无状态协议。
英汉互译系统设计—毕业设计(论文)
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摘要英汉互译系统是基于J2EE开发的,在J2SDK和Eclipse平台上使用java与Microsoft Access开发的,主要是解决个人及广大的朋友们实现英译汉、汉译英的功能,本系统实现对生词、错词进行添加、删除和修改。
之所以选择J2EE来开发本系统有诸多的优越性,下面分别介绍:J2EE的优越性:J2EE是一套全然不同于传统应用开发的技术架构,包含许多组件,主要可简化且规范应用系统的开发与部署,进而提高可移植性、安全与再用价值。
Java语言的优越性和前景:java是以撰写跨平台应用软件的面向对象的程序设计语言,是由Sun Microsystems公司于1995年5月推出的Java程序设计语言和Java平台(即JavaSE, JavaEE, JavaME)的总称。
Java 技术具有卓越的通用性、高效性、平台移植性和安全性,广泛应用于个人PC、数据中心、游戏控制台、科学超级计算机、移动电话和互联网,同时拥有全球最大的开发者专业社群。
在全球云计算和移动互联网的产业环境下,Java更具备了显著优势和广阔前景。
作品的选材:现在我们处于一个信息的时代,随着时代的进步,语言也伴随这进步,我们处在一个形形色色的语言大家庭中,会其他国家的语言变得尤为重要,而英语在这些语言中又显得突出了,之所以选择做一个英汉互译的翻译软件是为了帮助自己和他人能学习更多的英语词汇,提升自己的技能水平。
系统用程序的方式解决了那些非常复杂的操作,比如翻越词典,所有的步骤只需在电脑或者手机上安装即可查询。
只需要查询,添加,删除和修改简单的几步操作就可以完成,非常简单实用。
【关键词】 java技术;英汉互译;查询;删除;修改;添加AbstractTranslation system is based on J2EE development, developed using java the J2SDK and Eclipse platform and Microsoft Access, mainly to solve personal and the majority of the friends realized English to Chinese and Chinese to English functionality of the system to achieve the new words,wrong word to add, delete, and modify. Chose J2EE to develop the system has many advantages, the following were introduced:The superiority of J2EE:J2EE is a set of completely different from traditional application development, technical architecture, contains a number of components, mainly to simplify the specification of application systems development and deployment, and to improve portability, security and re-use value.The superiority of the Java language and prospects:java programming language in writing object-oriented cross-platform software applications, was launched in May 1995 by Sun Microsystems, Inc. Java programming language and the Java platform (ie JavaSE, JavaEE, and JavaME) general. Java technology has excellent versatility, efficiency, platform portability, and security, are widely used in personal PC, data center, gaming consoles, scientific supercomputers, mobile phones and the Internet, at the same time has the world's largest community of professional developers . Global cloud computing and mobile Internet industry environment, Java has significant advantages and broad prospects.The selection of works:Now we are in an information age, with the progress of the times, the language is also accompanied by this progress, we arein a diverse languages extended family, will be the language of the other countries has become particularly important, and the prominent English language , chose to do a translation translation software to help themselves and others to learn more English vocabulary, enhance their level of skills.Program to solve a very complex operation, such as crossing the dictionary, all the steps are simply installed on a computer or mobile phone can query. Only need a few simple steps operation can be completed, a very simple and practical.【Key Words】java technology; Translation; queries; delete; modified; Add目录第一章问题定义及内容简介 (9)1.1问题的定义 (9)1.2 内容简介 (9)第二章研究背景与研究意义 (10)2.1 研究背景 (10)2.2 研究意义 (11)第三章开发平台与语言简介 (13)3.1 Eclipse简介 (13)3.2 java 简介 (14)3.3 Access 简介 (15)第四章系统需求分析及可行性分析 (16)4.1 系统需求分析 (16)4.1.1 现状分析 (16)4.1.2 功能需求分析 (17)4.1.3 数据库需求分析 (17)4.1.4 系统数据流程分析 (18)4.2 系统总体功能介绍 (20)4.3 模块功能介绍 (20)4.3.1 主界面功能 (20)4.3.2 英译汉功能 (20)4.3.3 汉译英功能 (21)4.4 数据项 (21)4.5 系统难点分析 (23)第五章系统设计 (23)5.1系统的总体设计 (23)5.1.1系统的功能模块设计 (23)5.2 系统的详细设计 (25)5.2.1 概念设计 (25)5.3 系统的物理设计 (26)第六章总体设计 (27)6.1 算法的实现 (27)6.2 字符串的联系 (28)6.3 数据库设计 (28)6.3.1 数据库图 (28)6.3.2 数据库的约束与关系 (29)6.4 系统的实现 (29)6.4.1 主界面功能实现 (29)6.4.2 英译汉功能实现 (31)6.4.3 汉译英功能及词库备份实现 (32)6.4.4 查询类的实现及数据库绑定 (34)6.4.5 添加类的实现及数据库绑定 (35)6.4.6 修改类的实现及数据库绑定 (37)6.4.7 删除类的实现及数据库绑定 (39)第七章 Socket编程 (43)7.1 Socket编程 (43)7.2 Socket的实现 (43)第八章程序总结 (49)8.1 本系统的优点 (49)8.2 本系统的不足及改良 (50)8.3 设计和实现过程中的收获 (50)参考文献 (51)参考书籍: (51)谢辞 (53)第一章问题定义及内容简介1.1问题的定义解决英译汉、汉译英以及传统的英汉互译的软件缺陷进行以下的改变:1.实现添加生词到数据库,方便下次查询,备份词库、避免数据丢失。
第二章 GIS空间数据结构1
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二、矢量数据的特点
三、矢量数据结构的类型
1、简单数据结构 空间数据按照以基本的空间对象(点、线或多边形)为单元 进行单独组织,不含有拓扑关系数据,最典型的是面条 (Spaghetti)结构。
主要特点:
(1)数据按点、线或多边形为单元进行组织,数 据编排直观,数字化操作简单。 (2)每个多边形都以闭合线段存储,多边形的公 共边界被数字化两次和存储两次,造成数据 冗余和不一致。 (3)点、线和多边形有各自的坐标数据,但没有 拓扑数据,互相之间不关联。 (4)岛只作为一个单个图形,没有与外界多边形 的联系。
4、坐标系转换
x=f1(L,B) y=f2(L,B)
5、高程
指空间参考的高于或低于某基准平面的 垂直位置,主要用来提供地形信息。我国现 规定的高程基准面为“1985国家高程基准”, 比原“黄海平均海平面”高29mm。我国高程 的起算面是黄海平均海水面。1956年在青岛 设立了水准原点,称此为1956年黄海高程系。 1987年国家测绘局公布:中国的高程基准面 启用《1985国家高程基准》取代国务院1959 年批准启用的《黄海平均海水面》。《1985 国家高程基准》比《黄海平均海水面》上升 29毫米。
优、缺点
优点——文件结构简单,易于实现以多边形为单位的运 算和显示。 缺点—— (1)邻接多边形的公共边被数字化和存储两次(如图 2—19a中的7、8、9三个点),由此会产生数据冗余和 边界不重合(由于数字化误差等因素造成)。 (2) 每个多边形自成体系,缺少有关邻域关系的信 息,难以进行邻域处理。如合并同类时要消除公共边。 (3) 不能解决“洞”或“岛”之类的多边形嵌套问 题,岛只作为单个的图形建造,没有与外包多边形的 联系。 (4)不易检查多边形边界的拓扑关系是否正确,如 无法判断有无不完整的多边形。
计算机专业毕业论文外文翻译
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附录(英文翻译)Rich Client Tutorial Part 1The Rich Client Platform (RCP) is an exciting new way to build Java applications that can compete with native applications on any platform. This tutorial is designed to get you started building RCP applications quickly. It has been updated for Eclipse 3.1.2By Ed Burnette, SASJuly 28, 2004Updated for 3.1.2: February 6, 2006IntroductionTry this experiment: Show Eclipse to some friends or co-workers who haven't seen it before and ask them to guess what language it is written in. Chances are, they'll guess VB, C++, or C#, because those languages are used most often for high quality client side applications. Then watch the look on their faces when you tell them it was created in Java, especially if they are Java programmers.Because of its unique open source license, you can use the technologies that went into Eclipse to create your own commercial quality programs. Before version 3.0, this was possible but difficult, especially when you wanted to heavily customize the menus, layouts, and other user interface elements. That was because the "IDE-ness" of Eclipse was hard-wired into it. Version 3.0 introduced the Rich Client Platform (RCP), which is basically a refactoring of the fundamental parts of Eclipse's UI, allowing it to be used for non-IDE applications. Version 3.1 updated RCP with new capabilities, and, most importantly, new tooling support to make it easier to create than before.If you want to cut to the chase and look at the code for this part you can find it in the accompanying zip file. Otherwise, let's take a look at how to construct an RCP application.Getting startedRCP applications are based on the familiar Eclipse plug-in architecture, (if it's not familiar to you, see the references section). Therefore, you'll need to create a plug-in to be your main program. Eclipse's Plug-in Development Environment (PDE) provides a number of wizards and editors that take some of the drudgery out of the process. PDE is included with the Eclipse SDK download so that is the package you should be using. Here are the steps you should follow to get started.First, bring up Eclipse and select File > New > Project, then expand Plug-in Development and double-click Plug-in Project to bring up the Plug-in Project wizard. On the subsequent pages, enter a Project name such as org.eclipse.ui.tutorials.rcp.part1, indicate you want a Java project, select the version of Eclipse you're targeting (at least 3.1), and enable the option to Create an OSGi bundle manifest. Then click Next >.Beginning in Eclipse 3.1 you will get best results by using the OSGi bundle manifest. In contrast to previous versions, this is now the default.In the next page of the Wizard you can change the Plug-in ID and other parameters. Of particular importance is the question, "Would you like to create a rich client application?". Select Yes. The generated plug-in class is optional but for this example just leave all the other options at their default values. Click Next > to continue.If you get a dialog asking if Eclipse can switch to the Plug-in Development Perspective click Remember my decision and select Yes (this is optional).Starting with Eclipse 3.1, several templates have been provided to make creating an RCP application a breeze. We'll use the simplest one available and see how it works. Make sure the option to Create a plug-in using one of the templates is enabled, then select the Hello RCP template. This isRCP's equivalent of "Hello, world". Click Finish to accept all the defaults and generate the project (see Figure 1). Eclipse will open the Plug-in Manifest Editor. The Plug-in Manifest editor puts a friendly face on the various configuration files that control your RCP application.Figure 1. The Hello World RCP project was created by a PDE wizard.Taking it for a spinTrying out RCP applications used to be somewhat tedious. You had to create a custom launch configuration, enter the right application name, and tweak the plug-ins that were included. Thankfully the PDE keeps track of all this now. All you have to do is click on the Launch an Eclipse Application button in the Plug-in Manifest editor's Overview page. You should see a bare-bones Workbench start up (see Figure 2).Figure 2. By using thetemplates you can be up andrunning anRCPapplication inminutes.Making it aproductIn Eclipse terms a product is everything that goes with your application, including all the other plug-ins it depends on, a command to run the application (called the native launcher), and any branding (icons, etc.) that make your application distinctive. Although as we've just seen you can run a RCP application without defining a product, having one makes it a whole lot easier to run the application outside of Eclipse. This is one of the major innovations that Eclipse 3.1 brought to RCP development.Some of the more complicated RCP templates already come with a product defined, but the Hello RCP template does not so we'll have to make one.In order to create a product, the easiest way is to add a product configuration file to the project. Right click on the plug-in project and select New > Product Configuration. Then enter a file name for this new configuration file, such as part1.product. Leave the other options at their default values. Then click Finish. The Product Configuration editor will open. This editor lets you control exactly what makes up your product including all its plug-ins and branding elements.In the Overview page, select the New... button to create a new product extension. Type in or browse to the defining plug-in(org.eclipse.ui.tutorials.rcp.part1). Enter a Product ID such as product, and for the Product Application selectorg.eclipse.ui.tutorials.rcp.part1.application. Click Finish to define the product. Back in the Overview page, type in a new Product Name, for example RCP Tutorial 1.In Eclipse 3.1.0 if you create the product before filling inthe Product Name you may see an error appear in the Problems view. The error will go away when you Synchronize (see below). This is a known bug that is fixed in newer versions. Always use the latest available maintenance release for the version of Eclipse you're targeting!Now select the Configuration tab and click Add.... Select the plug-in you just created (org.eclipse.ui.tutorials.rcp.part1) and then click on Add Required Plug-ins. Then go back to the Overview page and press Ctrl+S or File > Save to save your work.If your application needs to reference plug-ins that cannot be determined until run time (for example the tomcat plug-in), then add them manually in the Configuration tab.At this point you should test out the product to make sure it runs correctly. In the Testing section of the Overview page, click on Synchronize then click on Launch the product. If all goes well, the application should start up just like before.Plug-ins vs. featuresOn the Overview page you may have noticed an option that says the product configuration is based on either plug-ins or features. The simplest kind of configuration is one based on plug-ins, so that's what this tutorial uses. If your product needs automatic update or Java Web Start support, then eventually you should convert it to use features. But take my advice and get it working without them first.Running it outside of EclipseThe whole point of all this is to be able to deploy and run stand-alone applications without the user having to know anything about the Java and Eclipse code being used under the covers. For a real application you may want to provide a self-contained executable generated by an install program like InstallShield or NSIS. That's really beyond the scope of this article though, so we'll do something simpler.The Eclipse plug-in loader expects things to be in a certain layout so we'll need to create a simplified version of the Eclipse install directory. This directory has to contain the native launcher program, config files,and all the plug-ins required by the product. Thankfully, we've given the PDE enough information that it can put all this together for us now.In the Exporting section of the Product Configuration editor, click the link to Use the Eclipse Product export wizard. Set the root directory to something like RcpTutorial1. Then select the option to deploy into a Directory, and enter a directory path to a temporary (scratch) area such as C:\Deploy. Check the option to Include source code if you're building an open source project. Press Finish to build and export the program.The compiler options for source and class compatibility in the Eclipse Product export wizard will override any options you have specified on your project or global preferences. As part of the Export process, the plug-in is code is recompiled by an Ant script using these options.The application is now ready to run outside Eclipse. When you're done you should have a structure that looks like this in your deployment directory:RcpTutorial1| .eclipseproduct| eclipse.exe| startup.jar+--- configuration| config.ini+--- pluginsmands_3.1.0.jarorg.eclipse.core.expressions_3.1.0.jarorg.eclipse.core.runtime_3.1.2.jarorg.eclipse.help_3.1.0.jarorg.eclipse.jface_3.1.1.jarorg.eclipse.osgi_3.1.2.jarorg.eclipse.swt.win32.win32.x86_3.1.2.jarorg.eclipse.swt_3.1.0.jarorg.eclipse.ui.tutorials.rcp.part1_1.0.0.jarorg.eclipse.ui.workbench_3.1.2.jarorg.eclipse.ui_3.1.2.jarNote that all the plug-ins are deployed as jar files. This is the recommended format starting in Eclipse 3.1. Among other things this saves disk space in the deployed application.Previous versions of this tutorial recommended using a batch file or shell script to invoke your RCP program. It turns out this is a bad idea because you will not be able to fully brand your application later on. For example, you won't be able to add a splash screen. Besides, theexport wizard does not support the batch file approach so just stick with the native launcher.Give it a try! Execute the native launcher (eclipse or eclipse.exe by default) outside Eclipse and watch the application come up. The name of the launcher is controlled by branding options in the product configuration.TroubleshootingError: Launching failed because the org.eclipse.osgi plug-in is not included...You can get this error when testing the product if you've forgotten to list the plug-ins that make up the product. In the Product Configuration editor, select the Configuration tab, and add all your plug-ins plus all the ones they require as instructed above.Compatibility and migrationIf you are migrating a plug-in from version 2.1 to version 3.1 there are number of issues covered in the on-line documentation that you need to be aware of. If you're making the smaller step from 3.0 to 3.1, the number of differences is much smaller. See the References section for more information.One word of advice: be careful not to duplicate any information in both plug-in.xml and MANIFEST.MF. Typically this would not occur unless you are converting an older plug-in that did not use MANIFEST.MF into one that does, and even then only if you are editing the files by hand instead of going through the PDE.ConclusionIn part 1 of this tutorial, we looked at what is necessary to create a bare-bones Rich Client application. The next part will delve into the classes created by the wizards such as the WorkbenchAdvisor class. All the sample code for this part may be found in the accompanying zip file.ReferencesRCP Tutorial Part 2RCP Tutorial Part 3Eclipse Rich Client PlatformRCP Browser example (project org.eclipse.ui.examples.rcp.browser)PDE Does Plug-insHow to Internationalize your Eclipse Plug-inNotes on the Eclipse Plug-in ArchitecturePlug-in Migration Guide: Migrating to 3.1 from 3.0Plug-in Migration Guide: Migrating to 3.0 from 2.1译文:Rich Client教程第一部分The Rich Client Platform (RCP)是一种创建Java应用程序的令人兴奋的新方法,可以和任何平台下的自带应用程序进行竞争。
计算机专业外文资料翻译
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英文文献Object persistence and JavaBy Arsalan Saljoughy, , 05/01/97Object durability, or persistence, is the term you often hear used in conjunction with the issue of storing objects in databases. Persistence is expected to operate with transactional integrity, and as such it is subject to strict conditions. (See the Resources section of this article for more information on transaction processing.) In contrast, language services offered through standard language libraries and packages are often free from transactional constraints.As we'll see in this article, evidence suggests that simple Java persistence will likely stem from the language itself, while sophisticated database functionality will be offered by database vendors.No object is an islandIn the real world, you rarely find an object that lacks relations to other objects. Objects are components of object models. The issue of object durability transcends the issue of object model durability and distribution once we make the observation that objects are interconnected by virtue of their relations to one another.The relational approach to data storage tends to aggregate data by type. Rows in a table represent the physical aggregate of objects of the same type on disk. The relationships among objects are then represented by keys that are shared across many tables. Although through database organization, relational databases sometimes allow tables that are likely to be used together to be co-located (or clustered) in the same logical partition, such as a database segment, they have no mechanism to store object relationships in the database. Hence, in order to construct an object model, these relationships are constructed from the existing keys at run time in a process referred to as table joins. This is the same well-known property of the relational databases called data independence. Nearly all variants of object databases offer some mechanism to enhance the performance of a system that involves complex object relationships over traditional relational databases.To query or to navigate?In storing objects on disk, we are faced with the choice of co-locating related objects to better accommodate navigational access, or to store objects in table-like collections that aggregate objects by type to facilitate predicate-based access (queries), or both. The co-location of objects in persistent storage is an area where relational and object-oriented databases widely differ. The choice of the query language is another area of consideration. Structured Query Language (SQL) and extensions of it have provided relational systems with a predicate-basedaccess mechanism. Object Query Language (OQL) is an object variant of SQL, standardized by ODMG, but support for this language is currently scant. Polymorphic methods offer unprecedented elegance in constructing a semantic query for a collection of objects. For example, imagine a polymorphic behavior for acccount called isInGoodStanding. It may return the Boolean true for all accounts in good standing, and false otherwise. Now imagine the elegance of querying the collection of accounts, where inGoodStanding is implemented differently based on business rules, for all accounts in good standing. It may look something like:setOfGoodCustomers = setOfAccounts.query(account.inGoodStanding());While several of the existing object databases are capable of processing such a query style in C++ and Smalltalk, it is difficult for them to do so for larger (say, 500+ gigabytes) collections and more complex query expressions. Several of the relational database companies, such as Oracle and Informix, will soon offer other, SQL-based syntax to achieve the same result. Persistence and typeAn object-oriented language aficionado would say persistence and type are orthogonal properties of an object; that is, persistent and transient objects of the same type can be identical because one property should not influence the other. The alternative view holds that persistence is a behavior supported only by persistable objects and certain behaviors may apply only to persistent objects. The latter approach calls for methods that instruct persistable objects to store and retrieve themselves from persistent storage, while the former affords the application a seamless view of the entire object model -- often by extending the virtual memory system. Canonicalization and language independenceObjects of the same type in a language should be stored in persistent storage with the same layout, regardless of the order in which their interfaces appear. The processes of transforming an object layout to this common format are collectively known as canonicalization of object representation. In compiled languages with static typing (not Java) objects written in the same language, but compiled under different systems, should be identically represented in persistent storage.An extension of canonicalization addresses language-independent object representation. If objects can be represented in a language-independent fashion, it will be possible for different representations of the same object to share the same persistent storage.One mechanism to accomplish this task is to introduce an additional level of indirection through an interface definition language (IDL). Object database interfaces can be made through the IDL and the corresponding data structures. The downside of IDL style bindings is two fold: First, the extra level of indirection always requires an additional level of translation, which impacts the overall performance of the system; second, it limits use of database services that are unique to particular vendors and that might be valuable to application developers.A similar mechanism is to support object services through an extension of the SQL. Relational database vendors and smaller object/relational vendors are proponents of this approach; however, how successful these companies will be in shaping the framework for object storage remains to be seen.But the question remains: Is object persistence part of the object's behavior or is it an external service offered to objects via separate interfaces? How about collections of objects and methods for querying them? Relational, extended relational, and object/relational approaches tend to advocate a separation between language, while object databases -- and the Java language itself -- see persistence as intrinsic to the language:Native Java persistence via serializationObject serialization is the Java language-specific mechanism for the storage and retrieval of Java objects and primitives to streams. It is worthy to note that although commercial third-party libraries for serializing C++ objects have been around for some time, C++ has never offered a native mechanism for object serialization. Here's how to use Java's serialization: // Writing "foo" to a stream (for example, a file)// Step 1. Create an output stream// that is, create bucket to receive the bytesFileOutputStream out = new FileOutputStream("fooFile");// Step 2. Create ObjectOutputStream// that is, create a hose and put its head in the bucketObjectOutputStream os = new ObjectOutputStream(out)// Step 3. Write a string and an object to the stream// that is, let the stream flow into the bucketos.writeObject("foo");os.writeObject(new Foo());// Step 4. Flush the data to its destinationos.flush();The Writeobject method serializes foo and its transitive closure -- that is, all objects that can be referenced from foo within the graph. Within the stream only one copy of the serialized object exists. Other references to the objects are stored as object handles to save space and avoid circular references. The serialized object starts with the class followed by the fields of each class in the inheritance hierarchy.// Reading an object from a stream// Step 1. Create an input streamFileInputStream in = new FileInputStream("fooFile");// Step 2. Create an object input streamObjectInputStream ins = new ObjectInputStream(in);// Step 3. Got to know what you are readingString fooString = (String)ins.readObject();Foo foo = (Foo)s.readObject();Object serialization and securityBy default, serialization writes and reads non-static and non-transient fields from the stream. This characteristic can be used as a security mechanism by declaring fields that may not be serialized as private transient. If a class may not be serialized at all, writeObject and readObject methods should be implemented to throw NoAccessException.Persistence with transactional integrity: Introducing JDBCModeled after X/Open's SQL CLI (Client Level Interface) and Microsoft's ODBC abstractions, Java database connectivity (JDBC) aims to provide a database connectivity mechanism that is independent of the underlying database management system (DBMS).To become JDBC-compliant, drivers need to support at least the ANSI SQL-2 entry-level API, which gives third-party tool vendors and applications enough flexibility for database access.JDBC is designed to be consistent with the rest of the Java system. Vendors are encouraged to write an API that is more strongly typed than ODBC, which affords greater static type-checking at compile time.Here's a description of the most important JDBC interfaces:java.sql.Driver.Manager handles the loading of drivers and provides support for new database connections.java.sql.Connection represents a connection to a particular database.java.sql.Statement acts as a container for executing an SQL statement on a given connection.java.sql.ResultSet controls access to the result set.You can implement a JDBC driver in several ways. The simplest would be to build the driver as a bridge to ODBC. This approach is best suited for tools and applications that do not require high performance. A more extensible design would introduce an extra level of indirection to the DBMS server by providing a JDBC network driver that accesses the DBMS server through a published protocol. The most efficient driver, however, would directly access the DBMS proprietary API.Object databases and Java persistenceA number of ongoing projects in the industry offer Java persistence at the object level. However, as of this writing, Object Design's PSE (Persistent Storage Engine) and PSE Pro are the only fully Java-based, object-oriented database packages available (at least, that I am aware of). Check the Resources section for more information on PSE and PSE Pro.Java development has led to a departure from the traditional development paradigm for software vendors, most notably in the development process timeline. For example, PSE and PSE Pro are developed in a heterogeneous environment. And because there isn't a linking step in the development process, developers have been able to create various functional components independent of each other, which results in better, more reliable object-oriented code.PSE Pro has the ability to recover a corrupted database from an aborted transaction caused by system failure. The classes that are responsible for this added functionality are not present in the PSE release. No other differences exist between the two products. These products are what we call "dribbleware" -- software releases that enhance their functionality by plugging in new components. In the not-so-distant future, the concept of purchasing large, monolithic software would become a thing of the past. The new business environment in cyberspace, together with Java computing, enable users to purchase only those parts of the object model (object graph) they need, resulting in more compact end products.PSE works by post-processing and annotating class files after they have been created by the developer. From PSE's point of view, classes in an object graph are either persistent-capable or persistent-aware. Persistent-capable classes may persist themselves while persistent-aware classes can operate on persistent objects. This distinction is necessary because persistence may not be a desired behavior for certain classes. The class file post-processor makes the following modifications to classes:Modifies the class to inherit from odi.Persistent or odi.util.HashPersistent.Defines the initializeContents() method to load real values into hollow instances of your Persistent subclass. ObjectStore provides methods on the GenericObject class that retrieves each Field type.Be sure to call the correct methods for the fields in your persistent object. A separate method is available for obtaining each type of Field object. ObjectStore calls the initializeContents() method as needed. The method signature is:public void initializeContents(GenericObject genObj)Defines the flushContents() method to copy values from a modified instance (active persistent object) back to the database. ObjectStore provides methods on the GenericObject Be sure to call the correct methods for the fields in your persistent object. A separate method is available for setting each type of Field object. ObjectStore calls the flushContents() method as needed. The method signature is:public void flushContents(GenericObject genObj)Defines the clearContents() method to reset the values of an instance to the default values. This method must set all reference fields that referred to persistent objects to null. ObjectStore calls this method as needed. The method signature is:public void clearContents()Modifies the methods that reference non-static fields to call the Persistent.fetch() and Persistent.dirty() methods as needed. These methods must be called before the contents of persistent objects can be accessed or modified, respectively. While this step is not mandatory, it does provide a systematic way to ensure that the fetch() or dirty() method is called prior to accessing or updating object content.Defines a class that provides schema information about the persistence-capable class.All these steps can be completed either manually or automatically.PSE's transaction semanticYou old-time users of ObjectStore probably will find the database and transaction semantics familiar. There is a system-wide ObjectStore object that initializes the environment and is responsible for system-wide parameters. The Database class offers methods (such as create, open, and close), and the Transaction class has methods to begin, abort, or commit transactions. As with serialization, you need to find an entry point into the object graph. The getRoot and setRoot methods of the Database class serve this function. I think a few examples would be helpful here. This first snippet shows how to initialize ObjectStore:ObjectStore.initialize(serverName, null);try {db = Database.open(dbName, Database.openUpdate);} catch(DatabaseNotFoundException exception) {db = Database.create(dbName, 0664);}This next snippet shows how to start and commit a transaction:Transaction transaction = Transaction.begin(Transaction.update);try {foo = (Foo)db.getRoot("fooHead");} catch(DatabaseRootNotFoundException exception) {db.createRoot("fooHead", new Foo());}mit();The three classes specified above -- Transaction, Database, and ObjectStore -- are fundamental classes for ObjectStore. PSE 1.0 does not support nested transactions, backup and recovery, clustering, large databases, object security beyond what is available in the language, and any type of distribution. What is exciting, however, is all of this functionality will be incrementally added to the same foundation as the product matures.About the authorArsalan Saljoughy is asystems engineer specializing in object technology at Sun Microsystems. He earned his M.S. in mathematics from SUNY at Albany, and subsequently was a research fellow at the University of Berlin. Before joining Sun, he worked as a developer and as an IT consultant to financial services companies.ConclusionAlthough it is still too early to establish which methodology for object persistence in general and Java persistence in particular will be dominant in the future, it is safe to assume that a myriad of such styles will co-exist. The shift of storing objects as objects without disassembly into rows and columns is sure to be slow, but it will happen. In the meantime, we are more likely to see object databases better utilized in advanced engineering and telecommunications applications than in banking and back-office financial applications.英文翻译对象持久化和Java-深入的了解面向对象语言中的对象持久的讨论Arsalan Saljoughy,, 05/01/97对象持久化这个术语你常常会和数据存储一起听到。
【计算机专业文献翻译】J2EE体系结构
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毕业设计(论文)外文翻译要求1、毕业设计(论文)外文翻译应有两篇,总字符数不少于20000,其文献来源应由指导教师选定后以纸质(复印或打印件)形式随同毕业设计(论文)任务书一并发给学生。
复印或打印件上应有指导教师和专业教研室主任的签名和日期。
要求每位学生的外文翻译内容不重复。
2、翻译的外文文献应主要选自学术期刊、学术会议的文章、有关著作及其他相关材料,应与毕业论文(设计)主题相关,并列入毕业论文(设计)的参考文献;在每篇中文译文首页“页脚”处注明原文作者及出处,中文译文后应附外文原文(指导教师提供的原文,论文上应有指导教师和教研室主任签名)。
3、中文译文的基本撰写格式为:题目采用三号黑体字居中打印,正文采用宋体小四号字,行间距一般为固定值20磅,标准字符间距。
页边距为左3 cm,右2.5 cm,上下各2.5 cm,页面统一采用A4纸。
4、封面上的“外文翻译题目”指中文译文的题目;两篇外文文献,按“封面、译文一、外文原文(一)、译文二、外文原文(二)、外文翻译评阅表”的顺序统一装订。
赋予一个对该EJB的本地接口的引用,同时无需处理必不可少的JNDI查找。
●业务委托方法。
在这种方法中,业务接口的Web容器实现明确地托付给相应的EJB。
这具有允许高速缓存和允许故障操作在适当地点被重试的优点。
我们无需担心上述任一情况中的java.rmi.RemoteException捕获。
传输错误不会出现。
在这种体系结构中,和通过EJB来暴露一个远程接口的体系结构不同,EJB的使用仅仅是这种体系结构的一个实现选择而已,而不是一个基本特征。
不用改变总体设计,也不用EJB,就可以实现任何一个业务接口。
长处这种体系结构具有如下这些优点:●它没有分布式EJB应用那么复杂。
●EJB使用不更改应用的基本设计。
在这种体系结构中,只使这样一些对象成为EJB:它们需要一个EJB容器的那些服务。
●EJB使用只强加相当小的性能开销,因为没有远程方法调用或串行化。
gis专业毕业设计
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gis专业毕业设计
GIS(地理信息系统)专业毕业设计的主题可以根据你的兴趣和专业方向来选择。
以下是一些常见的GIS 毕业设计主题示例,供你参考:
1. 空间数据分析与可视化:利用GIS 技术进行空间数据的处理、分析和可视化,如地形分析、土地利用变化监测、人口分布分析等。
2. 地理信息系统应用开发:设计和开发GIS 应用程序,例如移动GIS 应用、WebGIS 平台、地理信息查询系统等。
3. 空间数据库设计与管理:设计和实施空间数据库,包括数据模型、数据存储、查询和检索功能等。
4. GIS 与遥感技术集成:结合遥感数据和GIS 技术,进行遥感图像处理、分类、解译等,应用于土地覆盖监测、环境评估等领域。
5. 地理信息系统在城市规划中的应用:利用GIS 进行城市规划和管理,如城市土地利用规划、交通规划、公共设施布局等。
6. 地理信息系统在环境保护中的应用:应用GIS 技术进行环境监测、生态评估、环境污染模拟等,助力环境保护和可持续发展。
7. 地理信息系统在灾害管理中的应用:利用GIS 进行灾害预警、风险评估、应急响应等,提高灾害管理的效率和准确性。
计算机专业毕业设计外文翻译
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外文翻译Birth of the NetThe Internet has had a relatively brief, but explosive history so far. It grew out of an experiment begun in the 1960's by the U.S. Department of Defense. The DoD wanted to create a computer network that would continue to function in the event of a disaster, such as a nuclear war. If part of the network were damaged or destroyed, the rest of the system still had to work. That network was ARPANET, which linked U.S. scientific and academic researchers. It was the forerunner of today's Internet.In 1985, the National Science Foundation (NSF) created NSFNET, a series of networks for research and education communication. Based on ARPANET protocols, the NSFNET created a national backbone service, provided free to any U.S. research and educational institution. At the same time, regional networks were created to link individual institutions with the national backbone service.NSFNET grew rapidly as people discovered its potential, and as new software applications were created to make access easier. Corporations such as Sprint and MCI began to build their own networks, which they linked to NSFNET. As commercial firms and other regional network providers have taken over the operation of the major Internet arteries, NSF has withdrawn from the backbone business.NSF also coordinated a service called InterNIC, which registered all addresses on the Internet so that data could be routed to the right system. This service has now been taken over by Network Solutions, Inc., in cooperation with NSF.How the Web WorksThe World Wide Web, the graphical portion of the Internet, is the most popular part of the Internet by far. Once you spend time on the Web,you will begin to feel like there is no limit to what you can discover. The Web allows rich and diverse communication by displaying text, graphics, animation, photos, sound and video.So just what is this miraculous creation? The Web physically consists of your personal computer, web browser software, a connection to an Internet service provider, computers called servers that host digital data and routers and switches to direct the flow of information.The Web is known as a client-server system. Your computer is the client; the remote computers that store electronic files are the servers. Here's how it works:Let's say you want to pay a visit to the the Louvre museum website. First you enter the address or URL of the website in your web browser (more about this shortly). Then your browser requests the web page from the web server that hosts the Louvre's site. The Louvre's server sends the data over the Internet to your computer. Your web browser interprets the data, displaying it on your computer screen.The Louvre's website also has links to the sites of other museums, such as the Vatican Museum. When you click your mouse on a link, you access the web server for the Vatican Museum.The "glue" that holds the Web together is called hypertext and hyperlinks. This feature allow electronic files on the Web to be linked so you can easily jump between them. On the Web, you navigate through pages of information based on what interests you at that particular moment, commonly known as browsing or surfing the Net.To access the Web you need web browser software, such as Netscape Navigator or Microsoft Internet Explorer. How does your web browser distinguish between web pages and other files on the Internet? Web pages are written in a computer language called Hypertext Markup Language or HTML.Some Web HistoryThe World Wide Web (WWW) was originally developed in 1990 at CERN, the European Laboratory for Particle Physics. It is now managed by The World Wide Web Consortium, also known as the World Wide Web Initiative.The WWW Consortium is funded by a large number of corporate members, including AT&T, Adobe Systems, Inc., Microsoft Corporation and Sun Microsystems, Inc. Its purpose is to promote the growth of the Web by developing technical specifications and reference software that will be freely available to everyone. The Consortium is run by MIT with INRIA (The French National Institute for Research in Computer Science) acting as European host, in collaboration with CERN.The National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign, was instrumental in the development of early graphical software utilizing the World Wide Web features created by CERN. NCSA focuses on improving the productivity of researchers by providing software for scientific modeling, analysis, and visualization. The World Wide Web was an obvious way to fulfill that mission. NCSA Mosaic, one of the earliest web browsers, was distributed free to the public. It led directly to the phenomenal growth of the World Wide Web.Understanding Web AddressesYou can think of the World Wide Web as a network of electronic files stored on computers all around the world. Hypertext links these resources together. Uniform Resource Locators or URLs are the addresses used to locate thesefiles. The information contained in a URL gives you the ability to jump from one web page to another with just a click of your mouse. When you type a URL into your browser or click on a hypertext link, your browser is sending a request to a remote computer to download a file.What does a typical URL look like? Here are some examples:/The home page for study english.ftp:///pub/A directory of files at MIT* available for downloading.news:rec.gardens.rosesA newsgroup on rose gardening.The first part of a URL (before the two slashes* tells you the type of resource or method of access at that address. For example:•http - a hypertext document or directory•gopher - a gopher document or menu•ftp - a file available for downloading or a directory of such files•news - a newsgroup•telnet - a computer system that you can log into over the Internet•WAIS* - a database or document in a Wide Area Information Search database•file - a file located on a local drive (your hard drive)The second part is typically the address of the computer where the data or service is located. Additional parts may specify the names of files, the port to connect to, or the text to search for in a database.You can enter the URL of a site by typing it into the Location bar of your web browser, just under the toolbar.Most browsers record URLs that you want to use again, by adding them to a special menu. In Netscape Navigator, it's called Bookmarks. In Microsoft Explorer, it's called Favorites. Once you add a URL to your list, you can return to that web page simply by clicking on the name in your list, instead of retyping the entire URL.Most of the URLs you will be using start with http which stands for Hypertext Transfer Protocol*. http is the method by which HTML files are transferred over the Web. Here are some other important things to know about URLs:• A URL usually has no spaces.• A URL always uses forward slashes (//).If you enter a URL incorrectly, your browser will not be able to locate the site or resource you want. Should you get an error message or the wrong site, make sure you typed the address correctly.You can find the URL behind any link by passing your mouse cursor over the link. The pointer will turn into a hand and the URL will appear in the browser's status ba r, usually located at the bottom of your screen.Domain NamesWhen you think of the Internet, you probably think of ".com." Just what do those three letters at the end of a World Wide Web address mean?Every computer that hosts data on the Internet has a unique numerical address. For example, the numerical address for the White House is198.137.240.100. But since few people want to remember long strings of numbers, the Domain Name System (DNS)* was developed. DNS, a critical part of the Internet's technical infrastructure*, correlates* a numerical address to a word. To access the White House website, you could type its number into the address box of your web browser. But most people prefer to use "." In this case, the domain name is . In general, the three-letter domain name suffix* is known as a generictop-level domai n and describes the type of organization. In the last few years, the lines have somewhat blurred* between these categories..com - business (commercial).edu - educational.org - non-profit.mil - military.net - network provider.gov - governmentA domain name always has two or more parts separated by dots and typically consists of some form of an organization's name and the three-letter suffix. For example, the domain name for IBM is ""; the United Nations is "."If a domain name is available, and provided it does not infringe* on an existing trademark, anyone can register the name for $35 a year through Network Solutions, Inc., which is authorized to register .com, .net and .org domains. You can use the box below to see if a name is a available. Don't be surprised ifthe .com name you want is already taken, however. Of the over 8 million domain names, 85% are .com domains.ICANN, the Internet Corporation for Assigned Names and Numbers, manages the Domain Name System. As of this writing, there are plans to add additional top-level domains, such as .web and .store. When that will actually happen is anybody's guess.To check for, or register a domain name, type it into the search box.It should take this form: In addition to the generic top-level domains, 244 national top-level domains were established for countries and territories*, for example:.au - Australia.ca - Canada.fr - France.de - Germany.uk - United KingdomFor US $275 per name, you can also register an international domain name with Net Names. Be aware that some countries have restrictions for registering names.If you plan to register your own domain name, whether it's a .com or not, keep these tips in mind:The shorter the name, the better. (But it should reflect your family name, interest or business.)The name should be easy to remember.It should be easy to type without making mistakes.Remember, the Internet is global. Ideally, a domain name will "read" in a language other than English.Telephone lines were designed to carry the human voice, not electronic data from a computer. Modems were invented to convert digital computer signals into a form that allows them to travel over the phone lines. Those are the scratchy sounds you hear from a modem's speaker. A modem on theother end of the line can understand it and convert the sounds back into digital information that the computer can understand. By the way, the word modem stands for MOdulator/DEModulator.Buying and using a modem used to be relatively easy. Not too long ago, almost all modems transferred data at a rate of 2400 Bps (bits per second). Today, modems not only run faster, they are also loaded with features like error control and data compression. So, in addition to converting and interpreting signals, modems also act like traffic cops, monitoring and regulating the flow of information. That way, one computer doesn't send information until the receiving computer is ready for it. Each of these features, modulation, error control, and data compression, requires a separate kind of protocol and that's what some of those terms you see like V.32, V.32bis, V.42bis and MNP5 refer to.If your computer didn't come with an internal modem, consider buying an external one, because it is much easier to install and operate. For example, when your modem gets stuck (not an unusual occurrence), you need to turn it off and on to get it working properly. With an internal modem, that means restarting your computer--a waste of time. With an external modem it's as easy as flipping a switch.Here's a tip for you: in most areas, if you have Call Waiting, you can disable it by inserting *70 in front of the number you dial to connect to the Internet (or any online service). This will prevent an incoming call from accidentally kicking you off the line.This table illustrates the relative difference in data transmission speeds for different types of files. A modem's speed is measured in bits per second (bps). A 14.4 modem sends data at 14,400 bits per second. A 28.8 modem is twice as fast, sending and receiving data at a rate of 28,800 bits per second.Until nearly the end of 1995, the conventional wisdom was that 28.8 Kbps was about the fastest speed you could squeeze out of a regular copper telephoneline. Today, you can buy 33.6 Kbps modems, and modems that are capable of 56 Kbps. The key question for you, is knowing what speed modems your Internet service provider (ISP) has. If your ISP has only 28.8 Kbps modems on its end of the line, you could have the fastest modem in the world, and only be able to connect at 28.8 Kbps. Before you invest in a 33.6 Kbps or a 56 Kbps modem, make sure your ISP supports them.Speed It UpThere are faster ways to transmit data by using an ISDN or leased line. In many parts of the U.S., phone companies are offering home ISDN at less than $30 a month. ISDN requires a so-called ISDN adapter instead of a modem, and a phone line with a special connection that allows it to send and receive digital signals. You have to arrange with your phone company to have this equipment installed. For more about ISDN, visit Dan Kegel's ISDN Page.An ISDN line has a data transfer rate of between 57,600 bits per second and 128,000 bits per second, which is at least double the rate of a 28.8 Kbps modem. Leased lines come in two configurations: T1 and T3. A T1 line offers a data transfer rate of 1.54 million bits per second. Unlike ISDN, a T-1 line is a dedicated connection, meaning that it is permanently connected to the Internet. This is useful for web servers or other computers that need to be connected to the Internet all the time. It is possible to lease only a portion of a T-1 line using one of two systems: fractional T-1 or Frame Relay. You can lease them in blocks ranging from 128 Kbps to 1.5 Mbps. The differences are not worth going into in detail, but fractional T-1 will be more expensive at the slower available speeds and Frame Relay will be slightly more expensive as you approach the full T-1 speed of 1.5 Mbps. A T-3 line is significantly faster, at 45 million bits per second. The backbone of the Internet consists of T-3 lines. Leased lines are very expensive and are generally only used by companies whose business is built around the Internet or need to transfer massiveamounts of data. ISDN, on the other hand, is available in some cities for a very reasonable price. Not all phone companies offer residential ISDN service. Check with your local phone company for availability in your area.Cable ModemsA relatively new development is a device that provides high-speed Internet access via a cable TV network. With speeds of up to 36 Mbps, cable modems can download data in seconds that might take fifty times longer with a dial-up connection. Because it works with your TV cable, it doesn't tie up a telephone line. Best of all, it's always on, so there is no need to connect--no more busy signals! This service is now available in some cities in the United States and Europe.The download times in the table above are relative and are meant to give you a general idea of how long it would take to download different sized files at different connection speeds, under the best of circumstances. Many things can interfere with the speed of your file transfer. These can range from excessive line noise on your telephone line and the speed of the web server from which you are downloading files, to the number of other people who are simultaneously trying to access the same file or other files in the same directory.DSLDSL (Digital Subscriber Line) is another high-speed technology that is becoming increasingly popular. DSL lines are always connected to the Internet, so you don't need to dial-up. Typically, data can be transferred at rates up to 1.544 Mbps downstream and about 128 Kbps upstream over ordinary telephone lines. Since a DSL line carries both voice and data, you don't have to install another phone line. You can use your existing line to establish DSLservice, provided service is available in your area and you are within the specified distance from the telephone company's central switching office.DSL service requires a special modem. Prices for equipment, DSL installation and monthly service can vary considerably, so check with your local phone company and Internet service provider. The good news is that prices are coming down as competition heats up.Anatomy of a Web PageA web page is an electronic document written in a computer language called HTML, short for Hypertext Markup Language. Each web page has a unique address, called a URL* or Uniform Resource Locator, which identifies its location on the network.A website has one or more related web pages, depending on how it's designed. Web pages on a site are linked together through a system of hyperlinks* , enabling you to jump between them by clicking on a link. On the Web, you navigate through pages of information according to your interests.Home Sweet Home PageWhen you browse the World Wide Web you'll see the term home page often. Think of a home page as the starting point of a website. Like the table of contents of a book or magazine, the home page usually provides an overview of what you'll find at the website. A site can have one page, many pages or a few long ones, depending on how it's designed. If there isn't a lot of information, the home page may be the only page. But usually you will find at least a few other pages.Web pages vary wildly in design and content, but most use a traditional magazine format. At the top of the page is a masthead* or banner graphic*, then a list of items, such as articles, often with a brief description. The items in the list usually link to other pages on the website, or to other sites. Sometimes these links are highlighted* words in the body of the text, or are arranged in a list, like an index. They can also be a combination* of both. A web page can also have images that link to other content.How can you tell which text are links? Text links appear in a different color from the rest of the text--typically in blue and underlined. When you move yourcursor over a text link or over a graphic link, it will change from an arrow to a hand. The hypertext words often hint* at what you will link to.When you return to a page with a link you've already visited, the hypertext words will often be in a different color, so you know you've already been there. But you can certainly go there again. Don't be surprised though, if the next time you visit a site, the page looks different and the information has changed. The Web is a dynamic* medium. To encourage visitors to return to a site, some web publishers change pages often. That's what makes browsing the Web so excitingA Home (Page) of Your OwnIn the 60s, people asked about your astrological* sign. In the 90s, they want to know your URL. These days, having a web address is almost as important as a street address. Your website is an electronic meeting place for your family, friends and potentially*, millions of people around the world. Building your digital domain can be easier than you may think. Best of all, you may not have to spend a cent. The Web brims with all kinds of free services, from tools to help you build your site, to free graphics, animation and site hosting. All it takes is some time and creativity.Think of your home page as the starting point of your website. Like the table of contents of a book or magazine, the home page is the front door. Your site can have one or more pages, depending on how you design it. If there isn't a lot of information just yet, your site will most likely have only a home page. But the site is sure to grow over time.While web pages vary dramatically* in their design and content, most use a traditional magazine layout. At the top of the page is a banner graphic. Next comes a greeting and a short description of the site. Pictures, text, and links to other websites follow.If the site has more than one page, there's typically a list of items--similar to an index--often with a brief description. The items in the list link to other pages on the website. Sometimes these links are highlighted words in the body of the text. It can also be a combination of both. Additionally, a web page may have images that link to other content.Before you start building your site, do some planning. Think about whom the site is for and what you want to say. Next, gather up the material that you wantto put on the site: write the copy, scan the photos, design or find the graphics. Draw a rough layout on a sheet of paper.While there are no rules you have to follow, there are a few things to keep in mind:•Start simply. If you are too ambitious at the beginning, you may never get the site off the ground. You can always add to your site.•Less is better. Most people don't like to read a lot of text online. Break it into small chunks.•Use restraint. Although you can use wild colors and images for the background of your pages, make sure your visitors will be able to readthe text easily.•Smaller is better. Most people connect to the Internet with a modem.Since it can take a long time to download large image files, keep the file sizes small.•Have the rights. Don't put any material on your site unless you are sure you can do it legally. Read Learn the Net's copyright article for moreabout this.Stake Your ClaimNow it's time to roll up your sleeves and start building. Learn the Net Communities provides tools to help you build your site, free web hosting, and a community of other homesteaders.Your Internet service provider may include free web hosting services with an account, one alternative to consider.Decoding Error MessagesAs you surf the Net, you will undoubtedly find that at times you can't access certain websites. Why, you make wonder? Error messages attempt to explain the reason. Unfortunately, these cryptic* messages baffle* most people.We've deciphered* the most common ones you may encounter.400 - Bad RequestProblem: There's something wrong with the address you entered. You may not be authorized* to access the web page, or maybe it no longer exists.Solution: Check the address carefully, especially if the address is long. Make sure that the slashes are correct (they should be forward slashes) and that all the names are properly spelled. Web addresses are case sensitive, socheck that the names are capitalized in your entry as they are in the original reference to the website.401 - UnauthorizedProblem: You can't access a website, because you're not on the guest list, your password is invalid or you have entered your password incorrectly.Solution: If you think you have authorization, try typing your password again. Remember that passwords are case sensitive.403 - ForbiddenProblem: Essentially the same as a 401.Solution: Try entering your password again or move on to another site.404 - Not FoundProblem: Either the web page no longer exists on the server or it is nowhere to be found.Solution: Check the address carefully and try entering it again. You might also see if the site has a search engine and if so, use it to hunt for the document. (It's not uncommon for pages to change their addresses when a website is redesigned.) To get to the home page of the site, delete everything after the domain name and hit the Enter or Return key.503 - Service unavailableProblem: Your Internet service provider (ISP) or your company's Internet connection may be down.Solution: Take a stretch, wait a few minutes and try again. If you still have no luck, phone your ISP or system administrator.Bad file requestProblem: Your web browser may not be able to decipher the online form you want to access. There may also be a technical error in the form.Solution: Consider sending a message to the site's webmaster, providing any technical information you can, such as the browser and version you use.Connection refused by hostProblem: You don't have permission to access the page or your password is incorrect.Solution: Try typing your password again if you think you should have access.Failed DNS lookupProblem: DNS stands for the Domain Name System, which is the system that looks up the name of a website, finds a corresponding number (similar to a phone number), then directs your request to the appropriate web server on theInternet. When the lookup fails, the host server can't be located.Solution: Try clicking on the Reload or Refresh button on your browser toolbar. If this doesn't work, check the address and enter it again. If all else fails, try again later.File contains no dataProblem: The site has no web pages on it.Solution: Check the address and enter it again. If you get the same error message, try again later.Host unavailableProblem: The web server is down.Solution: Try clicking on the Reload or Refresh button. If this doesn't work, try again later.Host unknownProblem: The web server is down, the site may have moved, or you've been disconnected from the Net.Solution: Try clicking on the Reload or Refresh button and check to see that you are still online. If this fails, try using a search engine to find the site. It may have a new address.Network connection refused by the serverProblem: The web server is busy.Solution: Try again in a while.Unable to locate hostProblem: The web server is down or you've been disconnected from the Net.Solution: Try clicking on the Reload or Refresh button and check to see that you are still online.Unable to locate serverProblem: The web server is out-of-business or you may have entered the address incorrectly.Solution: Check the address and try typing it again.Web BrowsersA web browser is the software program you use to access the World Wide Web, the graphical portion of the Internet. The first browser, called NCSA Mosaic, was developed at the National Center for Supercomputing Applications in the early '90s. The easy-to-use point-and-click interface*helped popularize the Web, although few then could imagine the explosive growth that would soon occur.Although many different browsers are available, Microsoft Internet Explorer* and Netscape Navigator* are the two most popular ones. Netscape and Microsoft have put so much money into their browsers that the competition can't keep up. The pitched battle* between the two companies to dominate* the market has lead to continual improvements to the software. Version 4.0 and later releases of either browser are excellent choices. (By the way, both are based on NCSA Mosaic.) You can download Explorer and Navigator for free from each company's website. If you have one browser already, you can test out the other. Also note that there are slight differences between the Windows and MacIntosh* versions.You can surf to your heart's content, but it's easy to get lost in this electronic web. That's where your browser can really help. Browsers come loaded with all sorts of handy features. Fortunately, you can learn the basics in just a few minutes, then take the time to explore the advanced functions.Both Explorer and Navigator have more similarities than differences, so we'll primarily cover those. For the most up-to-date information about the browsers, and a complete tutorial, check the online handbook under the Help menu or go to the websites of the respective* software companies.Browser AnatomyWhen you first launch your web browser, usually by double-clicking on the icon on your desktop, a predefined web page, your home page, will appear. With Netscape Navigator for instance, you will be taken to Netscape's NetCenter.•The Toolbar (工具栏)The row of buttons at the top of your web browser, known as the toolbar, helps you travel through the web of possibilities, even keeping track ofwhere you've been. Since the toolbars for Navigator and Explorer differ slightly, we'll first describe what the buttons in common do:o The Back button returns you the previous page you've visited.o Use the Forward button to return to the page you just came from.o Home takes you to whichever home page you've chosen. (If you haven't selected one, it will return you to the default home page,usually the Microsoft or Netscape website.)。
计算机专业毕业设计外文翻译--JSP内置对象
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附录1 外文参考文献(译文)JSP内置对象有些对象不用声明就可以在JSP页面的Java程序片和表达式部分使用,这就是JSP 的内置对象。
JSP的内置对象有:request、response、session、application、out.response和request对象是JSP内置对象中较重要的两个,这两个对象提供了对服务器和浏览器通信方法的控制。
直接讨论这两个对象前,要先对HTTP协议—Word Wide Wed底层协议做简单介绍。
Word Wide Wed是怎样运行的呢?在浏览器上键入一个正确的网址后,若一切顺利,网页就出现了。
使用浏览器从网站获取HTML页面时,实际在使用超文本传输协议。
HTTP规定了信息在Internet上的传输方法,特别是规定吧浏览器与服务器的交互方法。
从网站获取页面时,浏览器在网站上打开了一个对网络服务器的连接,并发出请求。
服务器收到请求后回应,所以HTTP协议的核心就是“请求和响应”。
一个典型的请求通常包含许多头,称作请求的HTTP头。
头提供了关于信息体的附加信息及请求的来源。
其中有些头是标准的,有些和特定的浏览器有关。
一个请求还可能包含信息体,例如,信息体可包含HTML表单的内容。
在HTML表单上单击Submit 键时,该表单使用ACTION=”POST”或ACTION=”GET”方法,输入表单的内容都被发送到服务器上。
该表单内容就由POST方法或GET方法在请求的信息体中发送。
服务器发送请求时,返回HTTP响应。
响应也有某种结构,每个响应都由状态行开始,可以包含几个头及可能的信息体,称为响应的HTTP头和响应信息体,这些头和信息体由服务器发送给客户的浏览器,信息体就是客户请求的网页的运行结果,对于JSP 页面,就是网页的静态信息。
用户可能已经熟悉状态行,状态行说明了正在使用的协议、状态代码及文本信息。
例如,若服务器请求出错,则状态行返回错误及对错误描述,比如HTTP/1.1 404 Object Not Found。
软件工程专业毕业设计外文文献翻译
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软件工程专业毕业设计外文文献翻译1000字本文将就软件工程专业毕业设计的外文文献进行翻译,能够为相关考生提供一定的参考。
外文文献1: Software Engineering Practices in Industry: A Case StudyAbstractThis paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process, practices, and techniques that lead to the production of quality software. The software engineering practices were identified through a survey questionnaire and a series of interviews with the company’s software development managers, software engineers, and testers. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.IntroductionSoftware engineering is the discipline of designing, developing, testing, and maintaining software products. There are a number of software engineering practices that are used in industry to ensure that software products are of high quality, reliable, and maintainable. These practices include software development processes, software configuration management, software testing, requirements engineering, and project management. Software engineeringpractices have evolved over the years as a result of the growth of the software industry and the increasing demands for high-quality software products. The software industry has developed a number of software development models, such as the Capability Maturity Model Integration (CMMI), which provides a framework for software development organizations to improve their software development processes and practices.This paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The objective of the study was to identify the software engineering practices used by the company and to investigate how these practices contribute to the production of quality software.Research MethodologyThe case study was conducted with a large US software development company that produces software for aerospace and medical applications. The study was conducted over a period of six months, during which a survey questionnaire was administered to the company’s software development managers, software engineers, and testers. In addition, a series of interviews were conducted with the company’s software development managers, software engineers, and testers to gain a deeper understanding of the software engineering practices used by the company. The survey questionnaire and the interview questions were designed to investigate the software engineering practices used by the company in relation to software development processes, software configuration management, software testing, requirements engineering, and project management.FindingsThe research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company’s software development process consists of five levels of maturity, starting with an ad hoc process (Level 1) and progressing to a fully defined and optimized process (Level 5). The company has achieved Level 3 maturity in its software development process. The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The software engineering practices used by the company include:Software Configuration Management (SCM): The company uses SCM tools to manage software code, documentation, and other artifacts. The company follows a branching and merging strategy to manage changes to the software code.Software Testing: The company has adopted a formal testing approach that includes unit testing, integration testing, system testing, and acceptance testing. The testing process is automated where possible, and the company uses a range of testing tools.Requirements Engineering: The company has a well-defined requirements engineering process, which includes requirements capture, analysis, specification, and validation. The company uses a range of tools, including use case modeling, to capture and analyze requirements.Project Management: The company has a well-defined project management process that includes project planning, scheduling, monitoring, and control. The company uses a range of tools to support project management, including project management software, which is used to track project progress.ConclusionThis paper has reported a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process,practices, and techniques that lead to the production of quality software. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company uses a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.外文文献2: Agile Software Development: Principles, Patterns, and PracticesAbstractAgile software development is a set of values, principles, and practices for developing software. The Agile Manifesto represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. This paper presents an overview of agile software development, including its principles, patterns, and practices. The paper also discusses the benefits and challenges of agile software development.IntroductionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases.Agile Software Development PrinciplesAgile software development is based on a set of principles. These principles are:Customer satisfaction through early and continuous delivery of useful software.Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.Deliver working software frequently, with a preference for the shorter timescale.Collaboration between the business stakeholders and developers throughout the project.Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.Working software is the primary measure of progress.Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.Continuous attention to technical excellence and good design enhances agility.Simplicity – the art of maximizing the amount of work not done – is essential.The best architectures, requirements, and designs emerge from self-organizing teams.Agile Software Development PatternsAgile software development patterns are reusable solutions to common software development problems. The following are some typical agile software development patterns:The Single Responsibility Principle (SRP)The Open/Closed Principle (OCP)The Liskov Substitution Principle (LSP)The Dependency Inversion Principle (DIP)The Interface Segregation Principle (ISP)The Model-View-Controller (MVC) PatternThe Observer PatternThe Strategy PatternThe Factory Method PatternAgile Software Development PracticesAgile software development practices are a set ofactivities and techniques used in agile software development. The following are some typical agile software development practices:Iterative DevelopmentTest-Driven Development (TDD)Continuous IntegrationRefactoringPair ProgrammingAgile Software Development Benefits and ChallengesAgile software development has many benefits, including:Increased customer satisfactionIncreased qualityIncreased productivityIncreased flexibilityIncreased visibilityReduced riskAgile software development also has some challenges, including:Requires discipline and trainingRequires an experienced teamRequires good communicationRequires a supportive management cultureConclusionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. Agile software development has many benefits, including increased customer satisfaction, increased quality, increased productivity, increased flexibility, increased visibility, and reduced risk. Agile software development also has some challenges, including the requirement for discipline and training, the requirement for an experienced team, the requirement for good communication, and the requirement for a supportive management culture.。
计算机专业毕业设计--英文文献(含译文)
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外文文献原文THE TECHNIQUE DEVELOPMENT HISTORY OF JSPThe Java Server Pages( JSP) is a kind of according to web of the script plait distance technique, similar carries the script language of Java in the server of the Netscape company of server- side JavaScript( SSJS) and the Active Server Pages(ASP) of the Microsoft. JSP compares the SSJS and ASP to have better can expand sex, and it is no more exclusive than any factory or some one particular server of Web. Though the norm of JSP is to be draw up by the Sun company of, any factory can carry out the JSP on own system.The After Sun release the JSP( the Java Server Pages) formally, the this kind of new Web application development technique very quickly caused the people's concern. JSP provided a special development environment for the Web application that establishes the high dynamic state. According to the Sun parlance, the JSP can adapt to include the Apache WebServer, IIS4.0 on the market at inside of 85% server product.This chapter will introduce the related knowledge of JSP and Databases, and JavaBean related contents, is all certainly rougher introduction among them basic contents, say perhaps to is a Guide only, if the reader needs the more detailed information, pleasing the book of consult the homologous JSP.1.1 GENERALIZEThe JSP(Java Server Pages) is from the company of Sun Microsystems initiate, the many companies the participate to the build up the together of the a kind the of dynamic the state web the page technique standard, the it have the it in the construction the of the dynamic state the web page the strong but the do not the especially of the function. JSP and the technique of ASP of the Microsoft is very alike. Both all provide the ability that mixes with a certain procedure code and is explain by the language engine to carry out the procedure code in the code of HTML. Underneath we are simple of carry on the introduction to it.JSP pages are translated into servlets. So, fundamentally, any task JSP pages can perform could also be accomplished by servlets. However, this underlying equivalence does not mean that servlets and JSP pages are equally appropriate in all scenarios. The issue is not the power of the technology, it is the convenience, productivity, and maintainability of one or the other. After all, anything you can do on a particular computer platform in the Java programming language you could also do in assembly language. But it still matters which you choose.JSP provides the following benefits over servlets alone:• It is easier to write and maintain the HTML. Your static code is ordinary HTML: no extra backslashes, no double quotes, and no lurking Java syntax.• You can use standard Web-site development tools. Even HTML tools that know nothing about JSP can be used because they simply ignore the JSP tags.• You can divide up your development team. The Java programmers can work on the dynamic code. The Web developers can concentrate on the presentation layer. On large projects, this division is very important. Depending on the size of your team and the complexity of your project, you can enforce a weaker or stronger separation between the static HTML and the dynamic content.Now, this discussion is not to say that you should stop using servlets and use only JSP instead. By no means. Almost all projects will use both. For some requests in your project, you will use servlets. For others, you will use JSP. For still others, you will combine them with the MVC architecture . You want the appropriate tool for the job, and servlets, by themselves, do not complete your toolkit.1.2 SOURCE OF JSPThe technique of JSP of the company of Sun, making the page of Web develop the personnel can use the HTML perhaps marking of XML to design to turn the end page with format. Use the perhaps small script future life of marking of JSP becomes the dynamic state on the page contents.( the contents changes according to the claim of)The Java Servlet is a technical foundation of JSP, and the large Web applies the development of the procedure to need the Java Servlet to match with with the JSP and then can complete, this name of Servlet comes from the Applet, the local translation method of now is a lot of, this book in order not to misconstruction, decide the direct adoption Servlet but don't do any translation, if reader would like to, can call it as" small service procedure". The Servlet is similar to traditional CGI, ISAPI, NSAPI etc. Web procedure development the function of the tool in fact, at use the Java Servlet hereafter, the customer need not use again the lowly method of CGI of efficiency, also need not use only the ability come to born page of Web of dynamic state in the method of API that a certain fixed Web server terrace circulate. Many servers of Web all support the Servlet, even not support the Servlet server of Web directly and can also pass the additional applied server and the mold pieces to support the Servlet. Receive benefit in the characteristic of the Java cross-platform, the Servlet is also a terrace irrelevant, actually, as long as match the norm of Java Servlet, the Servlet is complete to have nothing to do with terrace and is to have nothing to do with server of Web. Because the Java Servlet is internal to provide the service by the line distance, need not start a progress to the each claimses, and make use of the multi-threadingmechanism can at the same time for several claim service, therefore the efficiency of Java Servlet is very high.But the Java Servlet also is not to has no weakness, similar to traditional CGI, ISAPI, the NSAPI method, the Java Servlet is to make use of to output the HTML language sentence to carry out the dynamic state web page of, if develop the whole website with the Java Servlet, the integration process of the dynamic state part and the static state page is an evil-foreboding dream simply. For solving this kind of weakness of the Java Servlet, the SUN released the JSP.A number of years ago, Marty was invited to attend a small 20-person industry roundtable discussion on software technology. Sitting in the seat next to Marty was James Gosling, inventor of the Java programming language. Sitting several seats away was a high-level manager from a very large software company in Redmond, Washington. During the discussion, the moderator brought up the subject of Jini, which at that time was a new Java technology. The moderator asked the manager what he thought of it, and the manager responded that it was too early to tell, but that it seemed to be an excellent idea. He went on to say that they would keep an eye on it, and if it seemed to be catching on, they would follow his company's usual "embrace and extend" strategy. At this point, Gosling lightheartedly interjected "You mean disgrace and distend."Now, the grievance that Gosling was airing was that he felt that this company would take technology from other companies and suborn it for their own purposes. But guess what? The shoe is on the other foot here. The Java community did not invent the idea of designing pages as a mixture of static HTML and dynamic code marked with special tags. For example, Cold Fusion did it years earlier. Even ASP (a product from the very software company of the aforementioned manager) popularized this approach before JSP came along and decided to jump on the bandwagon. In fact, JSP not only adopted the general idea, it even used many of the same special tags as ASP did.The JSP is an establishment at the model of Java servlets on of the expression layer technique, it makes the plait write the HTML to become more simple.Be like the SSJS, it also allows you carry the static state HTML contents and servers the script mix to put together the born dynamic state exportation. JSP the script language that the Java is the tacit approval, however, be like the ASP and can use other languages( such as JavaScript and VBScript), the norm of JSP also allows to use other languages.1.3 JSP CHARACTERISTICSIs a service according to the script language in some one language of the statures system this kind of discuss, the JSP should be see make is a kind of script language.However, be a kind of script language, the JSP seemed to be too strong again, almost can use all Javas in the JSP.Be a kind of according to text originally of, take manifestation as the central development technique, the JSP provided all advantages of the Java Servlet, and, when combine with a JavaBeans together, providing a kind of make contents and manifestation that simple way that logic separate. Separate the contents and advantage of logical manifestations is, the personnel who renews the page external appearance need not know the code of Java, and renew the JavaBeans personnel also need not be design the web page of expert in hand, can use to take the page of JavaBeans JSP to define the template of Web, to build up a from have the alike external appearance of the website that page constitute. JavaBeans completes the data to provide, having no code of Java in the template thus, this means that these templates can be written the personnel by a HTML plait to support. Certainly, can also make use of the Java Servlet to control the logic of the website, adjust through the Java Servlet to use the way of the document of JSP to separate website of logic and contents.Generally speaking, in actual engine of JSP, the page of JSP is the edit and translate type while carry out, not explain the type of. Explain the dynamic state web page development tool of the type, such as ASP, PHP3 etc., because speed etc. reason, have already can't satisfy current the large electronic commerce needs appliedly, traditional development techniques are all at to edit and translate the executive way change, such as the ASP → ASP+;PHP3 → PHP4.In the JSP norm book, did not request the procedure in the JSP code part( be called the Scriptlet) and must write with the Java definitely. Actually, have some engines of JSP are adoptive other script languages such as the EMAC- Script, etc., but actually this a few script languages also are to set up on the Java, edit and translate for the Servlet to carry out of. Write according to the norm of JSP, have no Scriptlet of relation with Java also is can of, however, mainly lie in the ability and JavaBeans, the Enterprise JavaBeanses because of the JSP strong function to work together, so even is the Scriptlet part not to use the Java, edit and translate of performance code also should is related with Java.1.4 JSP MECHANISMTo comprehend the JSP how unite the technical advantage that above various speak of, come to carry out various result easily, the customer must understand the differentiation of" the module develops for the web page of the center" and" the page develops for the web page of the center" first.The SSJS and ASP are all in several year ago to release, the network of that time is still very young, no one knows to still have in addition to making all business, datas and the expression logic enter the original web page entirely heap what better solvethe method. This kind of model that take page as the center studies and gets the very fast development easily. However, along with change of time, the people know that this kind of method is unwell in set up large, the Web that can upgrade applies the procedure. The expression logic write in the script environment was lock in the page, only passing to shear to slice and glue to stick then can drive heavy use. Express the logic to usually mix together with business and the data logics, when this makes be the procedure member to try to change an external appearance that applies the procedure but do not want to break with its llied business logic, apply the procedure of maintenance be like to walk the similar difficulty on the eggshell. In fact in the business enterprise, heavy use the application of the module already through very mature, no one would like to rewrite those logics for their applied procedure.HTML and sketch the designer handed over to the implement work of their design the Web plait the one who write, make they have to double work-Usually is the handicraft plait to write, because have no fit tool and can carry the script and the HTML contents knot to the server to put together. Chien but speech, apply the complexity of the procedure along with the Web to promote continuously, the development method that take page as the center limits sex to become to get up obviously.At the same time, the people always at look for the better method of build up the Web application procedure, the module spreads in customer's machine/ server the realm. JavaBeans and ActiveX were published the company to expand to apply the procedure developer for Java and Windows to use to come to develop the complicated procedure quickly by" the fast application procedure development"( RAD) tool. These techniques make the expert in the some realm be able to write the module for the perpendicular application plait in the skill area, but the developer can go fetch the usage directly but need not control the expertise of this realm.Be a kind of take module as the central development terrace, the JSP appeared. It with the JavaBeans and Enterprise JavaBeans( EJB) module includes the model of the business and the data logic for foundation, provide a great deal of label and a script terraces to use to come to show in the HTML page from the contents of JavaBeans creation or send a present in return. Because of the property that regards the module as the center of the JSP, it can drive Java and not the developer of Java uses equally. Not the developer of Java can pass the JSP label( Tags) to use the JavaBeans that the deluxe developer of Java establish. The developer of Java not only can establish and use the JavaBeans, but also can use the language of Java to come to control more accurately in the JSP page according to the expression logic of the first floor JavaBeans.See now how JSP is handle claim of HTTP. In basic claim model, a claimdirectly was send to JSP page in. The code of JSP controls to carry on hour of the logic processing and module of JavaBeanses' hand over with each other, and the manifestation result in dynamic state bornly, mixing with the HTML page of the static state HTML code. The Beans can be JavaBeans or module of EJBs. Moreover, the more complicated claim model can see make from is request other JSP pages of the page call sign or Java Servlets.The engine of JSP wants to chase the code of Java that the label of JSP, code of Java in the JSP page even all converts into the big piece together with the static state HTML contents actually. These codes piece was organized the Java Servlet that customer can not see to go to by the engine of JSP, then the Servlet edits and translate them automatically byte code of Java.Thus, the visitant that is the website requests a JSP page, under the condition of it is not knowing, an already born, the Servlet actual full general that prepared to edit and translate completes all works, very concealment but again and efficiently. The Servlet is to edit and translate of, so the code of JSP in the web page does not need when the every time requests that page is explain. The engine of JSP need to be edit and translate after Servlet the code end is modify only once, then this Servlet that editted and translate can be carry out. The in view of the fact JSP engine auto is born to edit and translate the Servlet also, need not procedure member begins to edit and translate the code, so the JSP can bring vivid sex that function and fast developments need that you are efficiently.Compared with the traditional CGI, the JSP has the equal advantage. First, on the speed, the traditional procedure of CGI needs to use the standard importation of the system to output the equipments to carry out the dynamic state web page born, but the JSP is direct is mutually the connection with server. And say for the CGI, each interview needs to add to add a progress to handle, the progress build up and destroy by burning constantly and will be a not small burden for calculator of be the server of Web. The next in order, the JSP is specialized to develop but design for the Web of, its purpose is for building up according to the Web applied procedure, included the norm and the tool of a the whole set. Use the technique of JSP can combine a lot of JSP pages to become a Web application procedure very expediently.JSP six built-in objectsrequest for:The object of the package of information submitted by users, by calling the object corresponding way to access the information package, namely the use of the target users can access the information.response object:The customer's request dynamic response to the client sent the data.session object1. What is the session: session object is a built-in objects JSP, it in the first JSP pages loaded automatically create, complete the conversation of management.From a customer to open a browser and connect to the server, to close the browser, leaving the end of this server, known as a conversation.When a customer visits a server, the server may be a few pages link between repeatedly, repeatedly refresh a page, the server should bethrough some kind of way to know this is the same client, which requires session object.2. session object ID: When a customer's first visit to a server on the JSP pages, JSP engines produce a session object, and assigned aString type of ID number, JSP engine at the same time, the ID number sent to the client, stored in Cookie, this session objects, and customers on the establishment of a one-to-one relationship. When a customer to connect to the server of the other pages, customers no longer allocated to the new session object, until, close your browser, the client-server object to cancel the session, and the conversation, and customer relationship disappeared. When a customer re-open the browser to connect to the server, the server for the customer to create a new session object.aplication target1. What is the application:Servers have launched after the application object, when a customer to visit the site between the various pages here, this application objects are the same, until the server is down. But with the session difference is that all customers of the application objects are the same, that is, all customers share this built-in application objects.2. application objects commonly used methods:(1) public void setAttribute (String key, Object obj): Object specified parameters will be the object obj added to the application object, and to add the subject of the designation of a keyword index.(2) public Object getAttribute (String key): access to application objects containing keywords for.out targetsout as a target output flow, used to client output data. out targets for the output data.Cookie1. What is Cookie:Cookie is stored in Web server on the user's hard drive section of the text. Cookie allow a Web site on the user's computer to store information on and then get back to it.For example, a Web site may be generated for each visitor a unique ID, and then to Cookie in the form of documents stored in each user's machine.If you use IE browser to visit Web, you will see all stored on your hard drive on the Cookie. They are most often stored in places: c: \ windows \ cookies (in Window2000 is in the C: \ Documents and Settings \ your user name \ Cookies).Cookie is "keyword key = value value" to preserve the format of the record.2. Targets the creation of a Cookie, Cookie object called the constructor can create a Cookie. Cookie object constructor has two string .parameters: Cookie Cookie name and value.Cookie c = new Cookie ( "username", "john");3. If the JSP in the package good Cookie object to send to the client, the use of the response addCookie () method.Format: response.addCookie (c)4. Save to read the client's Cookie, the use of the object request getCookies () method will be implemented in all client came to an array of Cookie objects in the form of order, to meet the need to remove the Cookie object, it is necessary to compare an array cycle Each target keywords.JSP的技术发展历史Java Server Pages(JSP)是一种基于web的脚本编程技术,类似于网景公司的服务器端Java脚本语言—— server-side JavaScript(SSJS)和微软的Active Server Pages(ASP)。
ArcGIS的数据结构
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ArcGIS的数据结构ArcGIS的数据结构⒈简介ArcGIS是一种广泛使用的地理信息系统(GIS)软件。
它提供了一个完整的、集成的平台,用于创建、管理、分析和可视化地理数据。
ArcGIS的数据结构是该软件的核心组成部分,下面将详细介绍各个组成部分。
⒉数据类型ArcGIS支持多种不同的数据类型,包括矢量数据和栅格数据。
矢量数据包括点、线和面等几何要素类型,用于表示实际地理对象的空间位置。
栅格数据则是基于栅格单元格的网格形式数据,用于表示连续和离散的地理现象。
⑴矢量数据矢量数据在ArcGIS中以要素类的形式存储,每个要素类由多个要素组成。
每个要素可以具有多个属性,如名称、类型和日期等。
矢量数据可以存储在多种文件格式中,包括Shape等。
⑵栅格数据栅格数据在ArcGIS中以栅格数据集的形式存储,它由栅格单元格组成,每个单元格包含一个特定值。
栅格数据可以表示地形高度、遥感图像和气候数据等。
ArcGIS支持多种栅格数据格式,如TIFF、GRID和IMG等。
⒊数据组织ArcGIS使用几种不同的方式来组织和管理数据,包括图层、数据库和项目。
⑴图层图层是ArcGIS中数据显示和分析的基本单位。
每个图层可以包含一个或多个要素类或栅格数据集。
图层可以用来叠加不同类型的地理数据,以便进行分析和可视化。
⑵数据库ArcGIS可以连接到各种数据库管理系统(DBMS),如Oracle、Microsoft SQL Server和PostgreSQL等。
使用数据库可以提供更复杂的数据管理和查询功能,并支持多用户共享数据。
⑶项目项目是ArcGIS中组织和管理数据的一种方式。
一个项目可以包含多个图层、表格和地图等,使用户可以轻松访问和共享数据。
项目还可以包含地图布局和地理处理任务等。
⒋数据输入与编辑ArcGIS提供了多种方式来输入和编辑地理数据。
⑴数据输入ArcGIS可以从多种数据源导入地理数据,包括文件、数据库和互联网服务。
用户可以将地理数据以不同的文件格式(如Shape)导入到ArcGIS中进行进一步处理和分析。
毕业设计论文外文文献翻译计算机科学与技术微软VisualStudio中英文对照
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外文文献翻译(2012届)学生姓名学号********专业班级计算机科学与技术08-5班指导教师微软Visual Studio1微软Visual StudioVisual Studio 是微软公司推出的开发环境,Visual Studio可以用来创建Windows平台下的Windows应用程序和网络应用程序,也可以用来创建网络服务、智能设备应用程序和Office 插件。
Visual Studio是一个来自微软的集成开发环境IDE(inteqrated development environment),它可以用来开发由微软视窗,视窗手机,Windows CE、.NET框架、.NET精简框架和微软的Silverlight支持的控制台和图形用户界面的应用程序以及Windows窗体应用程序,网站,Web应用程序和网络服务中的本地代码连同托管代码。
Visual Studio包含一个由智能感知和代码重构支持的代码编辑器。
集成的调试工作既作为一个源代码级调试器又可以作为一台机器级调试器。
其他内置工具包括一个窗体设计的GUI应用程序,网页设计师,类设计师,数据库架构设计师。
它有几乎各个层面的插件增强功能,包括增加对支持源代码控制系统(如Subversion和Visual SourceSafe)并添加新的工具集设计和可视化编辑器,如特定于域的语言或用于其他方面的软件开发生命周期的工具(例如Team Foundation Server的客户端:团队资源管理器)。
Visual Studio支持不同的编程语言的服务方式的语言,它允许代码编辑器和调试器(在不同程度上)支持几乎所有的编程语言,提供了一个语言特定服务的存在。
内置的语言中包括C/C + +中(通过Visual C++),(通过Visual ),C#中(通过Visual C#)和F#(作为Visual Studio 2010),为支持其他语言,如M,Python,和Ruby等,可通过安装单独的语言服务。
计算机专业中英文翻译外文翻译文献翻译
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英文参考文献及翻译Linux - Operating system of cybertimes Though for a lot of people , regard Linux as the main operating system to make up huge work station group, finish special effects of " Titanic " make , already can be regarded as and show talent fully. But for Linux, this only numerous news one of. Recently, the manufacturers concerned have announced that support the news of Linux to increase day by day, users' enthusiasm to Linux runs high unprecedentedly too. Then, Linux only have operating system not free more than on earth on 7 year this piece what glamour, get the favors of such numerous important software and hardware manufacturers as the masses of users and Orac le , Informix , HP , Sybase , Corel , Intel , Netscape , Dell ,etc. , OK?1.The background of Linux and characteristicLinux is a kind of " free (Free ) software ": What is called free,mean users can obtain the procedure and source code freely , and can use them freely , including revise or copy etc.. It is a result of cybertimes, numerous technical staff finish its research and development together through Inte rnet, countless user is it test and except fault , can add user expansion function that oneself make conveniently to participate in. As the most outstanding one in free software, Linux has characteristic of the following:(1)Totally follow POSLX standard, expand the network operatingsystem of supporting all AT&T and BSD Unix characteristic. Because of inheritting Unix outstanding design philosophy , and there are clean , stalwart , high-efficient and steady kernels, their all key codes are finished by Li nus Torvalds and other outstanding programmers, without any Unix code of AT&T or Berkeley, so Linu x is not Unix, but Linux and Unix are totally compatible.(2)Real many tasks, multi-user's system, the built-in networksupports, can be with such seamless links as NetWare , Windows NT , OS/2 ,Unix ,etc.. Network in various kinds of Unix it tests to be fastest in comparing and assess efficiency. Support such many kinds of files systems as FAT16 , FAT32 , NTFS , Ex t2FS , ISO9600 ,etc. at the same time .(3) Can operate it in many kinds of hardwares platform , including such processors as Alpha , SunSparc , PowerPC , MIPS ,etc., to various kinds of new-type peripheral hardwares, can from distribute on global numerous programmer there getting support rapidly too.(4) To that the hardware requires lower, can obtain very good performance on more low-grade machine , what deserves particular mention is Linux outstanding stability , permitted " year " count often its running times.2.Main application of Linux At present,Now, the application of Linux mainly includes:(1) Internet/Intranet: This is one that Linux was used most at present, it can offer and include Web server , all such Inter net services as Ftp server , Gopher server , SMTP/POP3 mail server , Proxy/Cache server , DNS server ,etc.. Linux kernel supports IPalias , PPP and IPtunneling, these functions can be used for setting up fictitious host computer , fictitious service , VPN (fictitious special-purpose network ) ,etc.. Operating Apache Web server on Linux mainly, the occupation rate of market in 1998 is 49%, far exceeds the sum of such several big companies as Microsoft , Netscape ,etc..(2) Because Linux has outstanding networking ability , it can be usedin calculating distributedly large-scaly, for instance cartoon making , scientific caculation , database and file server ,etc..(3) As realization that is can under low platform fullness of Unix that operate , apply at all levels teaching and research work of universities and colleges extensively, if Mexico government announce middle and primary schools in the whole country dispose Linux and offer Internet service for student already.(4) Tabletop and handling official business appliedly. Application number of people of in this respect at present not so good as Windows of Microsoft far also, reason its lie in Lin ux quantity , desk-top of application software not so good as Windows application far not merely, because the characteristic of the freedom software makes it not almost have advertisement thatsupport (though the function of Star Office is not second to MS Office at the same time, but there are actually few people knowing).3.Can Linux become a kind of major operating system?In the face of the pressure of coming from users that is strengthened day by day, more and more commercial companies transplant its application to Linux platform, comparatively important incident was as follows, in 1998 ①Compaq and HP determine to put forward user of requirement truss up Linux at their servers , IBM and Dell promise to offer customized Linux system to user too. ②Lotus announce, Notes the next edition include one special-purpose edition in Linux. ③Corel Company transplants its famous WordPerfect to on Linux, and free issue. Corel also plans to move the other figure pattern process products to Linux platform completely.④Main database producer: Sybase , Informix , Oracle , CA , IBM have already been transplanted one's own database products to on Linux, or has finished Beta edition, among them Oracle and Informix also offer technical support to their products.4.The gratifying one is, some farsighted domestic corporations have begun to try hard to change this kind of current situation already. Stone Co. not long ago is it invest a huge sum of money to claim , regard Linux as platform develop a Internet/Intranet solution, regard this as the core and launch Stone's system integration business , plan to set up nationwide Linux technical support organization at the same time , take the lead to promote the freedom software application and development in China. In addition domestic computer Company , person who win of China , devoted to Linux relevant software and hardware application of system popularize too. Is it to intensification that Linux know , will have more and more enterprises accede to the ranks that Linux will be used with domestic every enterprise to believe, more software will be planted in Linux platform. Meanwhile, the domestic university should regard Linux as the original version and upgrade already existing Unix content of courses , start with analysing the source code and revising the kernel and train a large number of senior Linux talents, improve our country's own operating system. Having only really grasped the operating system, the software industry of our country could be got rid of and aped sedulously at present, the passive state led by the nose by others, create conditions for revitalizing the software industry of our country fundamentally.中文翻译Linux—网络时代的操作系统虽然对许多人来说,以Linux作为主要的操作系统组成庞大的工作站群,完成了《泰坦尼克号》的特技制作,已经算是出尽了风头。
gis 毕业设计
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gis 毕业设计GIS(地理信息系统)毕业设计GIS(地理信息系统)是一种将地理空间数据与属性数据相结合的技术,它在各个领域都有广泛的应用。
作为一名即将毕业的GIS专业学生,我将在本文中探讨我即将进行的毕业设计项目。
1. 项目背景我的毕业设计项目旨在应用GIS技术解决城市交通拥堵问题。
随着城市化进程的不断加速,交通拥堵已成为城市居民生活中的一大困扰。
因此,通过分析和优化交通网络,可以提高城市交通效率,改善人们的出行体验。
2. 数据收集与处理为了实现这个目标,我将收集大量的地理空间数据和交通数据。
地理空间数据包括道路网络、交通信号灯、公交站点等,而交通数据则包括车辆流量、交通事故等。
这些数据将通过各种方式获取,如地理调查、遥感影像解译、交通监测设备等。
在数据收集完成后,我将使用GIS软件对数据进行处理和分析。
首先,我将使用数据清洗和整理技术对原始数据进行预处理,以确保数据的准确性和一致性。
然后,我将使用空间分析工具来分析交通网络的瓶颈和拥堵点,以及交通事故的热点区域。
3. 交通网络优化基于数据分析的结果,我将提出一些交通网络优化的方案。
例如,我可以提出增加道路容量、调整交通信号灯时序、优化公交线路等措施。
这些方案将通过GIS软件进行模拟和评估,以确定其对交通拥堵的改善效果。
4. 可视化展示为了更好地展示我的毕业设计成果,我将使用GIS软件制作交通拥堵的可视化地图。
这些地图将直观地显示出交通瓶颈、拥堵区域和交通事故的分布情况。
此外,我还将利用GIS软件的动态模拟功能,展示交通网络优化方案的实际效果。
5. 结果与讨论最后,我将对我的毕业设计结果进行详细的分析和讨论。
我将评估交通网络优化方案的有效性,并讨论可能的改进措施。
此外,我还将探讨GIS技术在解决城市交通问题中的潜力和局限性,以及未来的发展方向。
通过这个毕业设计项目,我将综合运用所学的GIS知识和技术,解决实际问题并提出创新的解决方案。
我相信这个项目将为我的毕业设计增添深度和价值,并为我未来的职业发展奠定坚实的基础。
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外文文献GIS software and data structures(bilingual)1、Arc/InfoArc/Info is a long-lived full functions GIS package that has been ported to the microcomputer, the workstation, and the mainframe. Arc/Info is used to automate, manipulate, analyze, and display geographic data and incorporates hundreds of sophisticated tools for map automation, data conversion, database management, map overlay and spatial analysis, interactive display and query, graphic editing, and address geocoding. The software includes a relational database interface for integration with commercial database management systems and macro language for developing customized applications called AML (ARC Macro Language). Arc/Info is a generic nonapplication specific approach to geographic information systems, allowing the software to address virtually any geographic application. The software runs both on higher and microcomputers and is available on several Unix workstations and for Windows NT.2、ArcViewArcView is available for Windows, Macintosh, and a variety of Unix platforms. It is a desktop system for storing, modifying, querying, analyzing, and displaying information about geographic space. Support for spatial and tabular queries, “hot links” to other desktop applications and data types, business graphic functions such as charting, bar and pie charts, and map symbolization, desing, and layout capabilities are supported. Gocoding and address matching are also possible. ArcView is also a product of ESRI, who makes Arc/Info. There is compatibility between the two systems, with ArcView being more oriented toward map display than database management. When the ArcView version II software was introduced, the original ArcView software was placed into the public domain and is available over the Internet.3、Atlas GISAtlasGIS is available for both DOS and as version 3.0 for Windows. The original vendor has recently sold the software to Clartas, which in turn was purchased in 1996 by ESRI. This GIS lets you display, edit, and analyze information from a database or spreadsheet on a map, and can turn statistics and tabular data into graphics for decision-making and presentation purposes. Atlas GIS has a database management system with spreadsheet-style presentation, map editing, drawing tools, and reporting. Atlas GIS for Windows includes features that give SQL data access and street-level geocoding of addresses. Interfacing with the Oracle DBMS is also possible.The graphics allow full-featured geographical analysis and integrated database connectivity. In recent comparative reviews, three GIS and computer magazines awarded AtlasGIS for Windows the highest rating in value and ease of use. The GUI builds on Windows to allow “point and click” access, a button bar, and a page layout system that displays the map automatically. Several map “style sheets” come with the program. Legends, titles, scale bars and other elements update automatically. A CD ROM of U.S. addresses allows nationwide geocoding by address matching and supports mapping. A map layer management system let’s you click to change colors, settings, styles, visibility, and so on. Interface via Windows OLE, allowing cut and paste to other Windows applications, is possible.4、GRASSThe U.S. Army Construction Engineering Research Laboratories has developed publicdomain software called the Geographical Resources Analysis Support System (GRASS). Grass is raster based, was the first Unix GIS software, and has been considerably enhanced by the addition of user contributions, for example in hydrologic modeling. GRASS is available free over the Internet. Many users run GRASS on PC’s under the Linux version of UNIX. Since 1985, CERL has released upgrades and enhancements to GRASS and provided technical user support. CERL terminated GRASS related work in the spring of 1996. Under formal agreements, CERL now works with commercial vendors both to support GRASS and to integrate its capabilities into commercial system. Existing information on the GRASS WorldWide Web sites will be maintained for some time as background.5、IDRISIThe IDRISI software system has been developed, distributed, and supported on a notfor-profit basis by the IDRISI Project, Clark University Graduate School of Geography. To date, there are over 15,000 registered users of IDRISI software in over 130 countries, making it the most widely used raster GIS in the world. IDRISI is designed to be easy to use, yet provide professional-level GIS, image processing and spatial statistics analytical capability on both DOS- and Windows-based personal computers. It is intended to be affordable to all levels of users and to run on the most basic of common computer platforms. Expensive graphics cards or peripheral devices are not required to make use of the analytical power of the system. The system is designed with an open architecture so that researchers can integrate their own modules.IDRISI for Windows, first released in 1995, added a graphical user interface, flexible cartographic composition facilities, and integrated database management system to the analytical toolkit. Special routines for change and time-series analysis, spatial decision support, and uncertainty analysis and incorporation are included. The software comes with a set of tutorial exercises and data that guide the new user through the concepts of GIS and image processing while also introducing the features of IDRISI. The tutorial exercises are appropriate for use in self-training or in classroom settings.6、MapInfoMapInfo was one of the first GIS programs to do desktop mapping. The vendor is MapInfo Corporation of Troy, New York. The software is well distributed and has many user groups and a broad variety of applications worldwide. The software runs under DOS, Windows, Macintosh, and on various Unix platforms. While MapInfo’s GIS retrieval and analysis functions are fewer than those of full-blown GIS packages, MapInfo includes a link to the Basic programming language via a language called MapBasic. This development environment permits the creation of customized “mapplications”, extending MapInfo’s built-in functionality and allowing use of acommon graphical interface.MapInfo also supplies information products spanning geographic, economic, political, cultural, and industry application-specific content, each derived from leading worldwide sources to work the software. MapInfo also has an extensive training program, with classes at introductory and advanced levels for MapInfo and MapBasic.7、Microstation MGEMGE is widely distributed layer-based GIS with a tradition in computer assisted design by the Intergraph Corporation of Huntsville, Alabama. The software runs on workstations, PCs and under the Windows NT system. An extensive set of add on modules allow users to configure GIS capability around their specific needs. The layered implementation allows efficient storage structures for the geometry and linkages to relational database records. Geographic element is represented in the GIS as features. Features are grouped into the same categories as the maps on which they appear.For the attribute data, MGE incorporates use of the relational interface system, which facilitates client-server network communication to the relational DBMS so that multiple workstations communicate with the database server simultaneously. MGE contains tools for building and maintaining topologically clean data without the processing and storage overhead of building and maintaining topology. MGE supports the open geodata interoperability specification and the spatial data transfer standard.中文译文GIS软件和数据结构Arc/Info是一个产生早、功能齐全的地理信息系统软件包,它已经被安装到微型计算机、工作站以及电算机的主机中。