网站毕业设计外文翻译
毕业设计外文翻译_英文版
A Design and Implementation of Active NetworkSocket ProgrammingK.L. Eddie Law, Roy LeungThe Edward S. Rogers Sr. Department of Electrical and Computer EngineeringUniversity of TorontoToronto, Canadaeddie@, roy.leung@utoronto.caAbstract—The concept of programmable nodes and active networks introduces programmability into communication networks. Code and data can be sent and modified on their ways to destinations. Recently, various research groups have designed and implemented their own design platforms. Each design has its own benefits and drawbacks. Moreover, there exists an interoperability problem among platforms. As a result, we introduce a concept that is similar to the network socket programming. We intentionally establish a set of simple interfaces for programming active applications. This set of interfaces, known as Active Network Socket Programming (ANSP), will be working on top of all other execution environments in future. Therefore, the ANSP offers a concept that is similar to “write once, run everywhere.” It is an open programming model that active applications can work on all execution environments. It solves the heterogeneity within active networks. This is especially useful when active applications need to access all regions within a heterogeneous network to deploy special service at critical points or to monitor the performance of the entire networks. Instead of introducing a new platform, our approach provides a thin, transparent layer on top of existing environments that can be easily installed for all active applications.Keywords-active networks; application programming interface; active network socket programming;I. I NTRODUCTIONIn 1990, Clark and Tennenhouse [1] proposed a design framework for introducing new network protocols for the Internet. Since the publication of that position paper, active network design framework [2, 3, 10] has slowly taken shape in the late 1990s. The active network paradigm allows program code and data to be delivered simultaneously on the Internet. Moreover, they may get executed and modified on their ways to their destinations. At the moment, there is a global active network backbone, the ABone, for experiments on active networks. Apart from the immaturity of the executing platform, the primary hindrance on the deployment of active networks on the Internet is more on the commercially related issues. For example, a vendor may hesitate to allow network routers to run some unknown programs that may affect their expected routing performance. As a result, alternatives were proposed to allow active network concept to operate on the Internet, such as the application layer active networking (ALAN) project [4] from the European research community. In the ALAN project, there are active server systems located at different places in the networks and active applications are allowed to run in these servers at the application layer. Another potential approach from the network service provider is to offer active network service as the premium service class in the networks. This service class should provide the best Quality of Service (QoS), and allow the access of computing facility in routers. With this approach, the network service providers can create a new source of income.The research in active networks has been progressing steadily. Since active networks introduce programmability on the Internet, appropriate executing platforms for the active applications to execute should be established. These operating platforms are known as execution environments (EEs) and a few of them have been created, e.g., the Active Signaling Protocol (ASP) [12] and the Active Network Transport System (ANTS) [11]. Hence, different active applications can be implemented to test the active networking concept.With these EEs, some experiments have been carried out to examine the active network concept, for example, the mobile networks [5], web proxies [6], and multicast routers [7]. Active networks introduce a lot of program flexibility and extensibility in networks. Several research groups have proposed various designs of execution environments to offer network computation within routers. Their performance and potential benefits to existing infrastructure are being evaluated [8, 9]. Unfortunately, they seldom concern the interoperability problems when the active networks consist of multiple execution environments. For example, there are three EEs in ABone. Active applications written for one particular EE cannot be operated on other platforms. This introduces another problem of resources partitioning for different EEs to operate. Moreover, there are always some critical network applications that need to run under all network routers, such as collecting information and deploying service at critical points to monitor the networks.In this paper, a framework known as Active Network Socket Programming (ANSP) model is proposed to work with all EEs. It offers the following primary objectives.• One single programming interface is introduced for writing active applications.• Since ANSP offers the programming interface, the design of EE can be made independent of the ANSP.This enables a transparency in developing andenhancing future execution environments.• ANSP addresses the interoperability issues among different execution environments.• Through the design of ANSP, the pros and cons of different EEs will be gained. This may help design abetter EE with improved performance in future.The primary objective of the ANSP is to enable all active applications that are written in ANSP can operate in the ABone testbed . While the proposed ANSP framework is essential in unifying the network environments, we believe that the availability of different environments is beneficial in the development of a better execution environment in future. ANSP is not intended to replace all existing environments, but to enable the studies of new network services which are orthogonal to the designs of execution environments. Therefore, ANSP is designed to be a thin and transparent layer on top of all execution environments. Currently, its deployment relies on automatic code loading with the underlying environments. As a result, the deployment of ANSP at a router is optional and does not require any change to the execution environments.II. D ESIGN I SSUES ON ANSPThe ANSP unifies existing programming interfaces among all EEs. Conceptually, the design of ANSP is similar to the middleware design that offers proper translation mechanisms to different EEs. The provisioning of a unified interface is only one part of the whole ANSP platform. There are many other issues that need to be considered. Apart from translating a set of programming interfaces to other executable calls in different EEs, there are other design issues that should be covered, e.g., • a unified thread library handles thread operations regardless of the thread libraries used in the EEs;• a global soft-store allows information sharing among capsules that may execute over different environmentsat a given router;• a unified addressing scheme used across different environments; more importantly, a routing informationexchange mechanism should be designed across EEs toobtain a global view of the unified networks;• a programming model that should be independent to any programming languages in active networks;• and finally, a translation mechanism to hide the heterogeneity of capsule header structures.A. Heterogeneity in programming modelEach execution environment provides various abstractions for its services and resources in the form of program calls. The model consists of a set of well-defined components, each of them has its own programming interfaces. For the abstractions, capsule-based programming model [10] is the most popular design in active networks. It is used in ANTS [11] and ASP [12], and they are being supported in ABone. Although they are developed based on the same capsule model, their respective components and interfaces are different. Therefore, programs written in one EE cannot run in anther EE. The conceptual views of the programming models in ANTS and ASP are shown in Figure 1.There are three distinct components in ANTS: application, capsule, and execution environment. There exist user interfaces for the active applications at only the source and destination routers. Then the users can specify their customized actions to the networks. According to the program function, the applications send one or more capsules to carry out the operations. Both applications and capsules operate on top of an execution environment that exports an interface to its internal programming resources. Capsule executes its program at each router it has visited. When it arrives at its destination, the application at destination may either reply it with another capsule or presents this arrival event to the user. One drawback with ANTS is that it only allows “bootstrap” application.Figure 1. Programming Models in ASP and ANTS.In contrast, ASP does not limit its users to run “bootstrap” applications. Its program interfaces are different from ANTS, but there are also has three components in ASP: application client, environment, and AAContext. The application client can run on active or non-active host. It can start an active application by simply sending a request message to the EE. The client presents information to users and allows its users to trigger actions at a nearby active router. AAContext is the core of the network service and its specification is divided into two parts. One part specifies its actions at its source and destination routers. Its role is similar to that of the application in ANTS, except that it does not provide a direct interface with the user. The other part defines its actions when it runs inside the active networks and it is similar to the functional behaviors of a capsule in ANTS.In order to deal with the heterogeneity of these two models, ANSP needs to introduce a new set of programming interfaces and map its interfaces and execution model to those within the routers’ EEs.B. Unified Thread LibraryEach execution environment must ensure the isolation of instance executions, so they do not affect each other or accessThe authors appreciate the Nortel Institute for Telecommunications (NIT) at the University of Toronto to allow them to access the computing facilitiesothers’ information. There are various ways to enforce the access control. One simple way is to have one virtual machine for one instance of active applications. This relies on the security design in the virtual machines to isolate services. ANTS is one example that is using this method. Nevertheless, the use of multiple virtual machines requires relatively large amount of resources and may be inefficient in some cases. Therefore, certain environments, such as ASP, allow network services to run within a virtual machine but restrict the use of their services to a limited set of libraries in their packages. For instance, ASP provides its thread library to enforce access control. Because of the differences in these types of thread mechanism, ANSP devises a new thread library to allow uniform accesses to different thread mechanisms.C. Soft-StoreSoft-store allows capsule to insert and retrieve information at a router, thus allowing more than one capsules to exchange information within a network. However, problem arises when a network service can execute under different environments within a router. The problem occurs especially when a network service inserts its soft-store information in one environment and retrieves its data at a later time in another environment at the same router. Due to the fact that execution environments are not allowed to exchange information, the network service cannot retrieve its previous data. Therefore, our ANSP framework needs to take into account of this problem and provides soft-store mechanism that allows universal access of its data at each router.D. Global View of a Unified NetworkWhen an active application is written with ANSP, it can execute on different environment seamlessly. The previously smaller and partitioned networks based on different EEs can now be merging into one large active network. It is then necessary to advise the network topology across the networks. However, different execution environments have different addressing schemes and proprietary routing protocols. In order to merge these partitions together, ANSP must provide a new unified addressing scheme. This new scheme should be interpretable by any environments through appropriate translations with the ANSP. Upon defining the new addressing scheme, a new routing protocol should be designed to operate among environments to exchange topology information. This allows each environment in a network to have a complete view of its network topology.E. Language-Independent ModelExecution environment can be programmed in any programming language. One of the most commonly used languages is Java [13] due to its dynamic code loading capability. In fact, both ANTS and ASP are developed in Java. Nevertheless, the active network architecture shown in Figure 2 does not restrict the use of additional environments that are developed in other languages. For instance, the active network daemon, anted, in Abone provides a workspace to execute multiple execution environments within a router. PLAN, for example, is implemented in Ocaml that will be deployable on ABone in future. Although the current active network is designed to deploy multiple environments that can be in any programming languages, there lacks the tool to allow active applications to run seamlessly upon these environments. Hence, one of the issues that ANSP needs to address is to design a programming model that can work with different programming languages. Although our current prototype only considers ANTS and ASP in its design, PLAN will be the next target to address the programming language issue and to improve the design of ANSP.Figure 2. ANSP Framework Model.F. Heterogeneity of Capsule Header StructureThe structures of the capsule headers are different in different EEs. They carries capsule-related information, for example, the capsule types, sources and destinations. This information is important when certain decision needs to be made within its target environment. A unified model should allow its program code to be executed on different environments. However, the capsule header prevents different environments to interpret its information successfully. Therefore, ANSP should carry out appropriate translation to the header information before the target environment receives this capsule.III. ANSP P ROGRAMMING M ODELWe have outlined the design issues encountered with the ANSP. In the following, the design of the programming model in ANSP will be discussed. This proposed framework provides a set of unified programming interfaces that allows active applications to work on all execution environments. The framework is shown in Figure 2. It is composed of two layers integrated within the active network architecture. These two layers can operate independently without the other layer. The upper layer provides a unified programming model to active applications. The lower layer provides appropriate translation procedure to the ANSP applications when it is processed by different environments. This service is necessary because each environment has its own header definition.The ANSP framework provides a set of programming calls which are abstractions of ANSP services and resources. A capsule-based model is used for ANSP, and it is currently extended to map to other capsule-based models used in ANTSand ASP. The mapping possibility to other models remains as our future works. Hence, the mapping technique in ANSP allows any ANSP applications to access the same programming resources in different environments through a single set of interfaces. The mapping has to be done in a consistent and transparent manner. Therefore, the ANSP appears as an execution environment that provides a complete set of functionalities to active applications. While in fact, it is an overlay structure that makes use of the services provided from the underlying environments. In the following, the high-level functional descriptions of the ANSP model are described. Then, the implementations will be discussed. The ANSP programming model is based upon the interactions between four components: application client , application stub , capsule , and active service base.Figure 3. Information Flow with the ANSP.•Application Client : In a typical scenario, an active application requires some means to present information to its users, e.g., the state of the networks. A graphical user interface (GUI) is designed to operate with the application client if the ANSP runs on a non-active host.•Application Stub : When an application starts, it activates the application client to create a new instance of application stub at its near-by active node. There are two responsibilities for the application stub. One of them is to receive users’ instructions from the application client. Another one is to receive incoming capsules from networks and to perform appropriate actions. Typically, there are two types of actions, thatare, to reply or relay in capsules through the networks, or to notify the users regarding the incoming capsule. •Capsule : An active application may contain several capsule types. Each of them carries program code (also referred to as forwarding routine). Since the application defines a protocol to specify the interactions among capsules as well as the application stubs. Every capsule executes its forwarding routine at each router it visits along the path between the source and destination.•Active Service Base : An active service base is designed to export routers’ environments’ services and execute program calls from application stubs and capsules from different EEs. The base is loaded automatically at each router whenever a capsule arrives.The interactions among components within ANSP are shown in Figure 3. The designs of some key components in the ANSP will be discussed in the following subsections. A. Capsule (ANSPCapsule)ANSPXdr decode () ANSPXdr encode () int length ()Boolean execute ()New types of capsule are created by extending the abstract class ANSPCapsule . New extensions are required to define their own forwarding routines as well as their serialization procedures. These methods are indicated below:The execution of a capsule in ANSP is listed below. It is similar to the process in ANTS.1. A capsule is in serial binary representation before it issent to the network. When an active router receives a byte sequence, it invokes decode() to convert the sequence into a capsule. 2. The router invokes the forwarding routine of thecapsule, execute(). 3. When the capsule has finished its job and forwardsitself to its next hop by calling send(), this call implicitly invokes encode() to convert the capsule into a new serial byte representation. length() isused inside the call of encode() to determine the length of the resulting byte sequence. ANSP provides a XDR library called ANSPXdr to ease the jobs of encoding and decoding.B. Active Service Base (ANSPBase)In an active node, the Active Service Base provides a unified interface to export the available resources in EEs for the rest of the ANSP components. The services may include thread management, node query, and soft-store operation, as shown in Table 1.TABLE I. ACTIVE SERVICE BASE FUNCTION CALLSFunction Definition Descriptionboolean send (Capsule, Address) Transmit a capsule towards its destination using the routing table of theunderlying environment.ANSPAddress getLocalHost () Return address of the local host as an ANSPAddress structure. This isuseful when a capsule wants to check its current location.boolean isLocal (ANSPAddress) Return true if its input argument matches the local host’s address andreturn false otherwise.createThread () Create a new thread that is a class ofANSPThreadInterface (discussed later in Section VIA “Unified Thread Abstraction”).putSStore (key, Object) Object getSStore (key) removeSStore (key)The soft-store operations are provided by putSStore(), getSSTore(), and removeSStore(), and they put, retrieve, and remove data respectively. forName (PathName) Supported in ANSP to retrieve a classobject corresponding to the given path name in its argument. This code retrieval may rely on the code loading mechanism in the environment whennecessary.C. Application Client (ANSPClient)boolean start (args[])boolean start (args[],runningEEs) boolean start (args[],startClient)boolean start (args[],startClient, runningEE)Application Client is an interface between users and the nearby active source router. It does the following responsibilities.1. Code registration: It may be necessary to specify thelocation and name of the application code in some execution environments, e.g., ANTS. 2. Application initialization: It includes selecting anexecution environment to execute the application among those are available at the source router. Each active application can create an application client instance by extending the abstract class, ANSPClient . The extension inherits a method, start(), to automatically handle both the registration and initialization processes. All overloaded versions of start() accept a list of arguments, args , that are passed to the application stub during its initialization. An optional argument called runningEEs allows an application client to select a particular set of environment variables, specified by a list of standardized numerical environment ID, the ANEP ID, to perform code registration. If this argument is not specified, the default setting can only include ANTS and ASP. D. Application Stub (ANSPApplication)receive (ANSPCapsule)Application stubs reside at the source and destination routers to initialize the ANSP application after the application clients complete the initialization and registration processes. It is responsible for receiving and serving capsules from the networks as well as actions requested from the clients. A new instance is created by extending the application client abstract class, ANSPApplication . This extension includes the definition of a handling routine called receive(), which is invoked when a stub receives a new capsule.IV. ANSP E XAMPLE : T RACE -R OUTEA testbed has been created to verify the design correctnessof ANSP in heterogeneous environments. There are three types of router setting on this testbed:1. Router that contains ANTS and a ANSP daemonrunning on behalf of ASP; 2. Router that contains ASP and a ANSP daemon thatruns on behalf of ANTS; 3. Router that contains both ASP and ANTS.The prototype is written in Java [11] with a traceroute testing program. The program records the execution environments of all intermediate routers that it has visited between the source and destination. It also measures the RTT between them. Figure 4 shows the GUI from the application client, and it finds three execution environments along the path: ASP, ANTS, and ASP. The execution sequence of the traceroute program is shown in Figure 5.Figure 4. The GUI for the TRACEROUTE Program.The TraceCapsule program code is created byextending the ANSPCapsule abstract class. When execute() starts, it checks the Boolean value of returning to determine if it is returning from the destination. It is set to true if TraceCapsule is traveling back to the source router; otherwise it is false . When traveling towards the destination, TraceCapsule keeps track of the environments and addresses of the routers it has visited in two arrays, path and trace , respectively. When it arrives at a new router, it calls addHop() to append the router address and its environment to these two arrays. When it finally arrives at the destination, it sets returning to false and forwards itself back to the source by calling send().When it returns to source, it invokes deliverToApp() to deliver itself to the application stub that has been running at the source. TraceCapsule carries information in its data field through the networks by executing encode() and decode(), which encapsulates and de-capsulates its data using External Data Representation (XDR) respectively. The syntax of ANSP XDR follows the syntax of XDR library from ANTS. length() in TraceCapsule returns the data length, or it can be calculated by using the primitive types in the XDRlibrary.Figure 5. Flow of the TRACEROUTE Capsules.V. C ONCLUSIONSIn this paper, we present a new unified layered architecture for active networks. The new model is known as Active Network Socket Programming (ANSP). It allows each active application to be written once and run on multiple environments in active networks. Our experiments successfully verify the design of ANSP architecture, and it has been successfully deployed to work harmoniously with ANTS and ASP without making any changes to their architectures. In fact, the unified programming interface layer is light-weighted and can be dynamically deployable upon request.R EFERENCES[1] D.D. Clark, D.L. Tennenhouse, “Architectural Considerations for a NewGeneration of Protocols,” in Proc. ACM Sigcomm’90, pp.200-208, 1990. [2] D. Tennenhouse, J. M. Smith, W. D. Sicoskie, D. J. Wetherall, and G. J.Minden, “A survey of active network research,” IEEE Communications Magazine , pp. 80-86, Jan 1997.[3] D. Wetherall, U. Legedza, and J. Guttag, “Introducing new internetservices: Why and how,” IEEE Network Magazine, July/August 1998. [4] M. Fry, A. Ghosh, “Application Layer Active Networking,” in ComputerNetworks , Vol.31, No.7, pp.655-667, 1999.[5] K. W. Chin, “An Investigation into The Application of Active Networksto Mobile Computing Environments”, Curtin University of Technology, March 2000.[6] S. Bhattacharjee, K. L. Calvert, and E. W. Zegura, “Self OrganizingWide-Area Network Caches”, Proc. IEEE INFOCOM ’98, San Francisco, CA, 29 March-2 April 1998.[7] L. H. Leman, S. J. Garland, and D. L. Tennenhouse, “Active ReliableMulticast”, Proc. IEEE INFOCOM ’98, San Francisco, CA, 29 March-2 April 1998.[8] D. Descasper, G. Parulkar, B. Plattner, “A Scalable, High PerformanceActive Network Node”, In IEEE Network, January/February 1999.[9] E. L. Nygren, S. J. Garland, and M. F. Kaashoek, “PAN: a high-performance active network node supporting multiple mobile code system”, In the Proceedings of the 2nd IEEE Conference on Open Architectures and Network Programming (OpenArch ’99), March 1999. [10] D. L. Tennenhouse, and D. J. Wetherall. “Towards an Active NetworkArchitecture”, In Proceeding of Multimedia Computing and Networking , January 1996.[11] D. J. Wetherall, J. V. Guttag, D. L. Tennenhouse, “ANTS: A toolkit forBuilding and Dynamically Deploying Network Protocols”, Open Architectures and Network Programming, 1998 IEEE , 1998 , Page(s): 117 –129.[12] B. Braden, A. Cerpa, T. Faber, B. Lindell, G. Phillips, and J. Kann.“Introduction to the ASP Execution Environment”: /active-signal/ARP/index.html .[13] “The java language: A white paper,” Tech. Rep., Sun Microsystems,1998.。
二手物品交易网站毕业设计外文翻译(译文)
河北科技师范学院本科毕业设计外文翻译二手物品网上交易资源效率的贡献：eBay用户的实证研究院（系、部）名称：专业名称：学生姓名：学生学号：指导教师：2016年03月08日二手物品网上交易资源效率的贡献：eBay用户的实证研究Jens Clausen , Birgit Blättel-Mink , Lorenz Erdmann ,Christine Henseling 摘要：本文探讨了网上二手交易的可持续性的影响（对可持续发展的贡献，减少对环境的不利影响）。
eBay用户的一项调查显示，二手商品交易和自然资源的保护之间的联系很难实现。
其次，保护环境的动机和以可持续的方式采取行动的消费者群体之间的差别很大。
鉴于这些结果，从用户的角度考虑，本文试图寻找网上的二手交易对环境影响的一些客观提示。
由于交易所造成的温室气体排放量似乎比生产新产品的排放量要低得多。
本文的结论与二手交易和消费政策的一套建议有关。
购买二手商品的可持续性利益的信息应包括在一般消费者的信息，并且行为变化的参数应该是针对不同的消费者群体。
关键词：网上市场，在线拍卖，消费者，电子商务，应用产品，二手市场，可持续消费1.介绍在线拍卖和交易平台增加了可持续消费的机会。
基于网络的二手交易的潜力很大程度上来说是在延长产品的寿命，从而避免了由于购买新产品产生额外的环境压力。
到目前为止，私人家庭往往因为高交易成本未能利用二手物品的潜力。
二手货物贸易仍然局限于区域市场，这些障碍经常阻止本地区二手商品市场达到临界质量并阻止他们成为有吸引力的买家和卖家。
然而近年来，互联网和交易平台的迅速增加，比如eBay网，已经从根本上改变了这种市场的基本条件。
在线市场不仅大大增加了市场参与者的数量，也改变了传统分配给消费者和生产者的角色。
交换网站、拍卖平台和其他以互联网为基础的交易模式，用户不仅是买家，而且在同一时间，也成为了活跃产品或服务的卖家，这些已经改变了消费者的作用。
MVC设计模式THE-MVC-WEB-DESIGN-PATTERN大学毕业论文外文文献翻译及原文
毕业设计（论文）外文文献翻译文献、资料中文题目：MVC设计模式文献、资料英文题目：THE MVC-WEB DESIGN PATTERN文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：班级：姓名：学号：指导教师：翻译日期： 2017.02.14MVC设计模式Ralph F. Grove计算机科学，詹姆斯麦迪逊大学，哈里森堡，美国弗吉尼亚州***************Eray Ozkan计算机科学，詹姆斯麦迪逊大学，哈里森堡，美国弗吉尼亚州*****************关键字：web，web框架，设计模式，模型-视图-控制器模式摘要：模型-视图-控制器模式被引用为许多web开发框架的基础架构。
然而，用于web开发的MVC 版本随着原来的Smalltalk的MVC的演变而发生了一些改变。
本文介绍了对这些变化的分析，并提出了一种独立的Web-MVC模式，用于更准确的描述MVC是如何在web框架中实现的。
1.介绍模型-视图-控制器(Modle-View-Controller，MVC)设计模式被一些web应用框架作为基础架构，例如，Rails，以及Struts。
MVC最初是在施乐帕克研究中心(Goldberg和Robson，1985)开发的Smalltalk编程环境中实现的。
为了适应web框架，MVC已经演变成了另一种方式，最终成为一种不同于其他任何设计模式，也与原始的Smaltalk完全不同的模式的实现。
本文的第一个目标是介绍MVC设计模式，其中包括它的原始形态(第2节)以及现代众所周知的用于web应用框架的变更后的形态(第3节)。
第二个目标是对这个模式演变后发生的变化进行评估，同时呈现演变后版本的有效性(第3节)。
最后，我们提出了一个标准的MVC-Web设计模式的描述，用于反映目前在web框架中模式的使用，同时又能保持原始的MVC中令人满意的特性。
基于MVC的web应用框架的修订版本已经被提出了(Chun, Yanhua, 和Hanhong, 2003) (Barrett和Delaney, 2004)。
网页设计专业毕业设计外文翻译
Produce the design of the tool and realize automaticallyon the basis of JSP webpageIt is an important respect that Internet uses that Web develops technology, and JSP is the most advanced technology that Web is developed , it is present Web developer's first-selected technology. But because JSP has relatively high expectations for Web developer, a lot of general Web developers can not use this advanced technology . The discussion produces the design of the tool and realizes automatically on the basis of JSP webpage of the template and label storehouse, put forward concrete design philosophy and implementation method .With the popularization of WWW (World Wide Web ), the technology of the dynamic webpage is developed rapidly too. From original CGI (Common Gateway In-terface ) to ASP (Active Server Page ), have met the webpage developer to the demand for developing technology of the dynamic webpage to a certain extent. But no matter CGI or ASP have certain limitation, for instance, consuming to resources of the server of CGI, ASP can only be used etc. with Microsoft IIS, all these have limited scope of application of the technology, have hindered their popularization greatly. The vast page developers all look forward to a kind of unified page and develop technology earnestly, characteristic that this technology there should be：①Have nothing to do with the operating platform, can run on any Web or the application program server ;②Show the logic and page of application program that separates ; ③Offer codes to put in an position, simplify and develop the course based on interactive application program of Web.JSP (Java Server Page ) technology is designed and used for responding to the request that like this. JSP is developed technology by the new webpage that Sun MicroSystem Company put out in June of 1999, it is that Web based on Java Serv-let and the whole Java system develops technology, and Servlet2. Expansion of 1API. Utilize this technology, can set up advancedly , safely and stepping dynamic websites of the platform .Java is the future mainstream to develop technology , have a lot of advantages . JSP is Java important application technology on Internet/Intranet Web , get extensive support and admit, it can conbine with various kinds of Java technology together intactly , thus realize very complicated application.As a kind of technology of development based on text , taking showing as centre, JSP has offered all advantages of Java Servlet. Logic function in order to make sure and showing the function was separated , JSP can already work with JavaBeans , Enterprise JavaBeans (EJB ) and Servlet . The developer of JSP can finish the work that majority and website's logic are correlated with through using JavaBeans , EJB and Servlet , and only assign the work shown to JSP page to finish. Content and show advantage that logic separate lie in , upgrade person , page of appearanceneedn't understand Java code , the personnel upgrading Javas needn't be experts who design webpage either. This can define Web template in JSP page with Javas , in order to set up websites made up of a page with similar appearance. Java completion data offer, have Java code among template, this mean template these can write by one HTML person is it maintain to come.JSP develops technology as the webpage of the mainstream at present, has the following characteristics：(1) Separate the formulation and showing of the content : Using JSP technology, the page developer of Web can use HTML or XML identification to design and format the final page . Use JSP identification or bound foot turn into dynamic content of page actually (whether content according to is it come change to ask). Produce logic of content of the identification and JavaBeans package , truss up of the little script encapsulation, all scripts run in the end of the server. If key logic among identification and JavaBeans, then other people, such as Web administrative staff and page designer encapsulation, can edit and use JSP page , and does not influence the formulation of the content .(2) Emphasize the reusable package : Most JSP pages depend on the reusable one, the package stepping the platform finish more complicated treatment with required application program. Benefitting from the independence of operating platform of Java, the developer can be very convenient to share and exchange and carry out the ordinary package that operated, or make these packages used by more users. The method based on package has accelerated the total development course, the efficiency of improving the project and developing wholly greatly.Though JSP is powerful, it requires the webpage developer should be quite familiar with Java. There are still relatively few Java programmers now, for general webpage developer, the grammar of JSP is more difficult to grasp . So, need a kind of webpage developing instrument and offer commonly used JSP application to general webpage developer, is it understand general page develop developer of technology (HTML ) can use strong function of JSP too only to let.Systematic design object and main technology of use：(1)Design objectSystem this design object for understand but HTML understand general webpage developer of JSP offer a webpage developing instrument at all only, enable them to follow the systematic file, use the daily function of JSP through the label, produce one finally and only include static HTML and dynamic JSP webpage of JSP label.(2)Main technologyThis system is in the design, consider using the technology of the template and JSP label to realize mainly.1、Technology of the templateThe technology of the template is widely applied to various kinds of development and application system. It produces some commonly used frame structure in advance , uses the family to choose the template from the template storehouse conveniently according to the needs of one's own one, is it is it put up to go again by oneself to need , save construction period in user , facilitate use of user. In this system , classify the page according to the function type , sum up the commonly used page type, produce the template storehouse.2、Storehouse technology of the labelIn JSP, movements can create and visit the language target of the procedure and influence the element exported and flowed. JSP has defined six standard movements. Except six standard movement these, user can define own movement finish the specific function. These movements are known as the customer movement, they are the reusable procedure module . Through movement these, programmer can some encapsulation stand up too display function of page in JSP page, make the whole page more succinct and easier to maintain. In a JSP page, movements were transfered through the customer label in these customers. And the label storehouse (Tag Library ) is the set of the customer label.JSP label storehouse is that one kind produces the method based on script of XML through JavaBeans. It is one of the greatest characteristics of JSP. Through the label storehouse , can expand JSP application unrestrictedly , finish any complicated application demand.JSP label storehouse has the following characteristic：①Easy to use: The labels in JSP and general HTML marks are totally the same in appearance, it is as convenient as ordinary HTML mark to use.②The easy code is paid most attention to: Every label in the label storehouse can finish certain function . Define ready to eat one label storehouse , is it pack one Jar file the label storehouse to need only, then only need use this label storehouse in other systems afterwards, needn't develop codes again , has raised the system and developed efficiency greatly, have reduced the development cost.③The easy code is safeguarded: All application logic is encapsulated in label processor and JavaBeans, all labels concentrate on a label storehouse. If need to upgrade codes or need to revise the function on a webpage, only need to revise the corresponding label. Maintain way in unison through this kind , it is unnecessary in each webpage is it is it fix to act as to get onning, have reduce the work load safeguarded greatly, has economized the cost of safeguarding.④The easy system is expanded : If need to add the new function to the system , only need to define a new label to finish this function, do not need to do any change to other respects of thesystem. Can inherit JSP normal characteristics of various fields in the label storehouse. Can expand and increase the function of JSP unrestrictedly like this, and does not need to wait for the appearance of the next edition JSP .Systematic composition and realizing：(1)The system making upThis system is made up of four parts mainly：1、The database joins some: This system supports several daily databases , including Oracle, Sybase, MSSQLServer, MySQL and DB2, use JDBC and database to link to each other according to database type and database name , user name , password that users offer that users choose.2、The basic form of system produces some: After joining with the database , produce the basic form TC-Tables and TC-Columns of two systems according to the user name linking to each other with the database , TC-Tables form includes English name , Chinese name and some attribute of form belonging to this user in this database , for instance can revise , can inquire about ; The Chinese and English name of the row and some other attribute that TC-Columns form includes belonging to all forms of this user's in this database . For instance can show , can inquire about . Basic information of the database that these basic forms of two systems provide to user's institute for use in the course of development of the whole system.3、The template is chosen to produce some with the webpage: This part is a key part of a system. It includes two pieces of sub module .①The template is chosen some: The system offers the template to user and chooses the interface, let users choose the templates used from the template storehouse according to the need.②The template is dealt with some: According to template that user choose, system transfer designated template deal with module is it punish to go on to these template. When dealing with the label that the procedure meets in the template, offer the mutual interface to user, let user input parameter for designated label , prove system validity of label that user input. Finished the formulation of JSP page systematically finally.Webpage preview is with revising some: After the webpage was produced out, the system has offered a webpage preview window and code to user and looked over that revises the window. Through this preview window, users can look at the result of JSP page produced out in advance . If user static result of respect in page very satisfied, user can through code look over revise window revise HTML code of code. If users have further demands for the static result of the page, the system has also offered a piece of interface which transfers DreamWeaver editing machine to user, users can use it to carry on further modification and perfection to the static result of JSP page that is produced out .(2)Systematic realization1、Realization of the template storehouse and label storehouseThe planning and design of the label storehouse are essential in the whole system design, efficiency that the degree and system that are put in an position have operated that its relation has reached codes. Its planning should follow the following principle .(1) Should try one's best little including static HTML among label. To general user, the label is transparent. Users can not look over and revise labels . If include too many static HT-ML sentence in the label , will influence the modification and perfection of user's static result to the page, limit the use of the label.(2) Try one's best to raise the paying most attention to degree of the code. Is it is it is it is it is it is it get to JSP public JSP out to withdraw to use to try one's best to classify to go on to use, form labels. Do not use and realize this application repeatedly in each label . While revising and perfecting to using like this , only need to revise this label, maintenance of the easy code.(3) Facilitate users' use. While designing the label storehouse , should fully consider users' operating position , it can very easy and understanding and using labels conveniently to use the family.①Definition of the label storehouse: Define a label storehouse, must define a label storehouse and describe the file (TLD ) at first . This is a file of script based on XML, have defined the edition of XML in this file , codes used, the edition , name and definition and parameter of all labels included in this storehouse of the label storehouse of the edition of the label storehouse , JSP used describe, including the name of the label, corresponding Javas of label, description information of the label ,etc..②Realization of the label: One label first special Java type, this each must inherit TagSupports , this each is in javax. servlet. jsp. Define in tagext bag . In the labels, the parameter which includes this label initializes the subject treatment method (Handler ) of method (Set/Get ) , label and method available for making the first class label to adjust,etc..③Realization of the template : A template is that one contains JSP file that labels quoted . In order to quote the labels defined in the template , must introduce the label storehouse at first .＜％＠taglib uri＝“tag．tld”prefix＝“ctag”％＞Among them uri appoints the label storehouse to describe the route of the file ; Prefixes used when prefix appoints to quote labels.While quoting the designated label in the template , use the designated prefix while introducing the label storehouse, appoint the name of the label; It is the parameter assignment of the label.2、Systematic development environmentWhat this systematic subject procedure making is used is JBuilder 6 of Borland Company. 0, it is Front-Page2000 of Microsoft Company that the template is developed and used, what the label storehouse is developed and used is UltraEdit editing machine, what JDK is adopted is JDK1.4. The system testing environment is JRun3. 0.Java future mainstream to develop language, and Java using JSP will become major technology that Web will be developed in the future too mainly at Web. This system has adopted the label storehouse , one of the biggest characteristics of JSP, enable the general Web developer to use JSP strong dynamic page function conveniently too, develop JSP dynamic Web page of the modern techniques. Because this system adopts Java to develop, can run under the operating system of any support graphic interface , have realized complete having nothing to do with the platform. This system is easy to expand and perfect. Can consider offering the interface to user afterwards , will use the family to expand the template storehouse and label storehouse by oneself, strengthen the systematic function further.List of references：[1] Cay S. Horstmann,Gary Cornell. Java 2 key technology (CoreJava 2 ) [M ]. Beijing: Publishing house of the mechanical industry.[2] Bruce Eckel. Java programming thought (Thinking in Java ) [M ]. Beijing: Publishing house of the mechanical industry.[3] Joseph L. Weber. Java 2 programming is explained in detail (Using Java 2) [M ]. Beijing: Electronic Industry Press.[4] Borland Company. Building Applications with JBuilder.基于JSP网页自动生成工具的设计与实现Web开发技术是Internet应用的一个重要方面，而JSP又是Web开发的最先进的技术，是当前Web开发人员的首选技术。
毕业设计(论文)外文翻译【范本模板】
华南理工大学广州学院本科生毕业设计(论文）翻译英文原文名Review of Vibration Analysis Methods for Gearbox Diagnostics and Prognostics中文译名对变速箱振动分析的诊断和预测方法综述学院汽车工程学院专业班级车辆工程七班学生姓名刘嘉先学生学号201130085184指导教师李利平填写日期2015年3月15日英文原文版出处：Proceedings of the 54th Meeting of the Society for Machinery Failure Prevention Technology, Virginia Beach，V A, May 1-4，2000，p. 623-634译文成绩：指导教师(导师组长）签名：译文：简介特征提取技术在文献中有描述;然而，大多数人似乎掩盖所需的特定的预处理功能。
一些文件没有提供足够的细节重现他们的结果，并没有一个全面的比较传统的功能过渡齿轮箱数据。
常用术语,如“残差信号”,是指在不同的文件不同的技术.试图定义了状态维修社区中的常用术语和建立所需的特定的预处理加工特性。
本文的重点是对所使用的齿轮故障检测功能。
功能分为五个不同的组基于预处理的需要。
论文的第一部分将提供预处理流程的概述和其中每个特性计算的处理方案。
在下一节中，为特征提取技术描述，将更详细地讨论每一个功能。
最后一节将简要概述的宾夕法尼亚州立大学陆军研究实验室的CBM工具箱用于齿轮故障诊断。
特征提取概述许多类型的缺陷或损伤会增加机械振动水平。
这些振动水平，然后由加速度转换为电信号进行数据测量。
原则上,关于受监视的计算机的健康的信息被包含在这个振动签名。
因此，新的或当前振动签名可以与以前的签名进行比较,以确定该元件是否正常行为或显示故障的迹象。
在实践中，这种比较是不能奏效的。
由于大的变型中,签名的直接比较是困难的。
相反,一个涉及从所述振动署名数据特征提取更多有用的技术也可以使用。
JAVA毕业设计外文文献翻译
THE TECHNIQUE DEVELOPMENT HISTORY OF JSPBy:Kathy Sierra and Bert BatesSource: Servlet&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 JS P( 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 Webapplication that establishes the high dynamic state. According to the Sun parlance, the JSP can adapt to include the Apache WebServer, IIS4.0 on themarket 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 GENER ALIZEThe 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 appropriatein 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 youchoose.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 apGFDGpropriate tool for the job, and servlets, by themselves, do not completeyour 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 changesaccording 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 neednot 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-threading mechanism 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 ownpurposes. 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 theaforementioned 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 alsoallows to use other languages.1.3JSP 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.1.4JSP 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 solve the 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 claim directly 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 andefficiently. 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 Webapplication procedure very expediently.JSP的技术发展历史作者：Kathy Sierra and Bert Bates来源：Servlet&JSPJava 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)。
计算机专业毕业设计外文翻译
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.)。
毕业设计论文 外文文献翻译
毕业设计（论文）外文参考文献翻译计算机科学与信息工程系系（院）2008 届题目企业即时通Instant Messaging for Enterprises课题类型技术开发课题来源自选学生姓名许帅专业班级 04计算机科学与技术指导老师王占中职称工程师完成日期：2008年4 月 6 日目录I NSTANT M ESSAGING FOR E NTERPRISE (1)1. Tips (1)2. Introduction (1)3. First things first (2)4.The While-Accept loop (4)5. Per-Thread class (6)6. The Client class (7)企业即时通 (9)1.提示 (9)2.简介 (9)3.首先第一件事 (10)4.监听循环 (11)5.单线程类 (13)6.用户端类 (14)Instant Messaging for Enterprise1. TipsIf Java is, in fact, yet another computer programming language, you may question why it is so important and why it is being promoted as a revolutionary step in computer programming. The answer isn’t immediately obvious if you’re coming from a tr aditional programming perspective. Although Java is very useful for solving traditional standalone programming problems, it is also important because it will solve programming problems on the World Wide Web. What is the Web?The Web can seem a bit of a mys tery at first, with all this talk of “surfing,”“presence,” and “home pages.” It’s helpful to step back and see what it really is, but to do this you must understand client/server systems, another aspect of computing that is full of confusing issues. The primary idea of a client/server system is that you have a central repository of information，some kind of data, often in a database。
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WebsiteFrom Wikipedia, the free encyclopediaA website is a collection of related web pages, images, videos or other digital assets that are addressed relative to a common Uniform Resource Locator (URL), often consisting of only the domain name, or the IP address, and the root path in an Internet Protocol-based network. A web site is hosted on at least one web server, accessible via a network such as the Internet or a private local area network.A web page is a document, typically written in plain text interspersed with formatting instructions of Hypertext Markup Language (HTML, XHTML).A web page may incorporate elements from other websites with suitable markup anchors.Web pages are accessed and transported with the Hypertext Transfer Protocol (HTTP), which may optionally employ encryption (HTTP Secure, HTTPS) to provide security and privacy for the user of the web page content. The user's application, often a web browser, renders the page content according to its HTML markup instructions onto a display terminal.All publicly accessible websites collectively constitute the World Wide Web.the pages of a website can usually be accessed from a simple Uniform Resource Locator called the homepage. The URLs of the pages organize them into a hierarchy, although hyperlinking between them conveys the reader's perceived site structure and guides the reader's navigation of the site.Some websites require a subscription to access some or all of their content. Examples of subscription sites include many business sites, parts of many news sites, academic journal sites, gaming sites, message boards, web-based e-mail, social networking websites, and sites providing real-time stock market data.1.HistoryThe World Wide Web (WWW) was created in 1989 by CERN physicist Tim Berners-Lee.On 30 April 1993, CERN announced that the World Wide Web would be free to use for anyone.Before the introduction of HTML and HTTP, other protocols such as filetransfer protocol and the gopher protocol were used to retrieve individual files from a server. These protocols offer a simple directory structure which the user navigates and chooses files to download. Documents were most often presented as plain text files without formatting or were encoded in word processor formats.2.OverviewOrganized by function, a website may be（1）a personal website（2）a commercial website（3）a government website（4）a non-profit organization websiteIt could be the work of an individual, a business or other organization, and is typically dedicated to some particular topic or purpose. Any website can contain a hyperlink to any other website, so the distinction between individual sites, as perceived by the user, may sometimes be blurred.Websites are written in, or dynamically converted to HTML (Hyper Text Markup Language) and are accessed using a software interface classified as a user agent. Web pages can be viewed or otherwise accessed from a range of computer-based and Internet-enabled devices of various sizes, including desktop computers, laptops, PDAs and cell phones.A website is hosted on a computer system known as a web server, also called an HTTP server, and these terms can also refer to the software that runs on these systems and that retrieves and delivers the web pages in response to requests from the website users. Apache is the most commonly used web server software (according to Netcraft statistics) and Microsoft's Internet Information Server (IIS) is also commonly used.3. Static websiteA static website is one that has web pages stored on the server in the format that is sent to a client web browser. It is primarily coded in Hypertext Markup Language (HTML).Simple forms or marketing examples of websites, such as classic website, a five-page website or a brochure website are often static websites, because they present pre-defined, static information to the user. This may includeinformation about a company and its products and services via text, photos, animations, audio/video and interactive menus and navigation.This type of website usually displays the same information to all visitors. Similar to handing out a printed brochure to customers or clients, a static website will generally provide consistent, standard information for an extended period of time. Although the website owner may make updates periodically, it is a manual process to edit the text, photos and other content and may require basic website design skills and software.In summary, visitors are not able to control what information they receive via a static website, and must instead settle for whatever content the website owner has decided to offer at that time.They are edited using four broad categories of software:(1) Text editors, such as Notepad or TextEdit, where content and HTML markup are manipulated directly within the editor program(2) Wysiwyg offline editors, such as Microsoft FrontPage and Adobe Dreamweaver (previously Macromedia Dreamweaver), with which the site is edited using a GUI interface and the final HTML markup is generated automatically by the editor software(3) Wysiwyg online editors which create media rich online presentation like web pages, widgets, intro, blogs, and other documents.(4) Template-based editors, such as Rapidweaver and iWeb, which allow users to quickly create and upload web pages to a web server without detailed HTML knowledge, as they pick a suitable template from a palette and add pictures and text to it in a desktop publishing fashion without direct manipulation of HTML code.4. Dynamic websiteA dynamic website is one that changes or customizes itself frequently and automatically, based on certain criteria.Dynamic websites can have two types of dynamic activity: Code and Content. Dynamic code is invisible or behind the scenes and dynamic content is visible or fully displayed.(1) Dynamic codeThe first type is a web page with dynamic code. The code is constructed dynamically on the fly using active programming language instead of plain,static HTML.A website with dynamic code refers to its construction or how it is built, and more specifically refers to the code used to create a single web page. A dynamic web page is generated on the fly by piecing together certain blocks of code, procedures or routines. A dynamically-generated web page would call various bits of information from a database and put them together in a pre-defined format to present the reader with a coherent page. It interacts with users in a variety of ways including by reading cookies recognizing users' previous history, session variables, server side variables etc., or by using direct interaction (form elements, mouse overs, etc.). A site can display the current state of a dialogue between users, monitor a changing situation, or provide information in some way personalized to the requirements of the individual user.(2) Dynamic contentThe second type is a website with dynamic content displayed in plain view. Variable content is displayed dynamically on the fly based on certain criteria, usually by retrieving content stored in a database.A website with dynamic content refers to how its messages, text, images and other information are displayed on the web page and more specifically how its content changes at any given moment. The web page content varies based on certain criteria, either pre-defined rules or variable user input. For example, a website with a database of news articles can use a pre-defined rule which tells it to display all news articles for today's date. This type of dynamic website will automatically show the most current news articles on any given date. Another example of dynamic content is when a retail website with a database of media products allows a user to input a search request for the keyword Beatles. In response, the content of the web page will spontaneously change the way it looked before, and will then display a list of Beatles products like CD's, DVD's and books.5. Software systemsThere is a wide range of software systems, such as Java Server Pages (JSP), the PHP and Perl programming languages, Active Server Pages (ASP), Yuma and ColdFusion (CFML) that are available to generate dynamic web systems and dynamic sites. Sites may also include content that is retrievedfrom one or more databases or by using XML-based technologies such as RSS.Static content may also be dynamically generated either periodically, or if certain conditions for regeneration occur (cached) in order to avoid the performance loss of initiating the dynamic engine on a per-user or per-connection basis.Plugins are available to expand the features and abilities of web browsers, which use them to show active content, such as Microsoft Silverlight, Adobe Flash, Adobe Shockwave or applets written in Java. Dynamic HTML also provides for user interactivity and real time element updating within web pages (ie pages don't have to be loaded or reloaded to effect any changes), mainly using the Document Object Model (DOM) and JavaScript, support which is built-in to most modern web browsers.Turning a website into an income source is a common practice for web developers and website owners. There are several methods for creating a website business which fall into two broad categories, as defined below.(1) Content-based siteSome websites derive revenue by selling advertising space on the site (see Contextual advertising).(2) Product- or service-based sitesSome websites derive revenue by offering products or services for sale. In the case of e-commerce websites, the products or services may be purchased at the website itself, by entering credit card or other payment information into a payment form on the site. While most business websites serve as a shop window for existing brick and mortar businesses, it is increasingly the case that some websites are businesses in their own right; that is, the products they offer are only available for purchase on the web.Websites occasionally derive income from a combination of these two practices. For example, a website such as an online auctions website may charge the users of its auction service to list an auction, but also display third-party advertisements on the site, from which it derives further income.网站文章来自维基百科，自由的百科全书网站是一组相关的网页，图片，视频或其他数字资产的集合，是针对相对的一个共同的统一资源定位符（URL），这个定位器往往由域名，或组成的IP地址在以网络为基础的互联网协议上的根路径构成。