计算机专业英语第五章
计算机专业英语教案第5章
第5章Computer Applications5.1 Word Processing5.2 Multimedia5.3 Computer Graphics5.4 Database Applications5.5 Computer Virus5.1 Word Processing•Personal computer-based office automation software has become an indispensable part of electronic management in many countries.•Word processing programs have replaced typewriters; spreadsheet programs have replaced ledger books; database programs have replaced paper-based electoral rolls, inventories and staff lists;personal organizer programs have replaced paper diaries; and so on.•Word processing refers to the methods and procedures involved in using a computer to create, edit, and print documents.•Word processing software has replaced typewriters for producing documents such as reports, letters, papers, and manuscripts.The advantage of word processing•The great advantage of word processing over using a typewriter is that you can make changes without retyping the entire document.•If you want to delete a paragraph, you simply remove it, without leaving a trace.•It is equally easy to insert a word, sentence, or paragraph in the middle of a document.•Word processors also make it easy to move sections of text from one place to another within a document, or between documents.•Most standard word processing features are supported, including footnotes and mail-merge but no tables or columns.•The interface uses customizable toolbars, and the editing screen isa zoom-able draft mode that optionally displays headers, footnotes,and footers.Microsoft Word•Microsoft Word is a powerful word processing application that will allow you, through simple keystroke and menu navigation, to create dynamic documents for work, school, or personal use.•Word processors vary considerably, but all word processors support some basic features.Full-featured word processors usually support the following features •Insert and Delete text•Cut, paste and copy•Page size and margins•Search and replace•Word wrap•Print•File management•Font specifications•Footnotes and cross-references•Graphics•Headers, footers and page numbering•Layout•Macros•Merge•Spell checker•Tables of contents and indexes•Thesaurus•Windows•WYSIWYG(What Y ou See Is What Y ou Get)5.4 Database Applications•Database systems are designed to manage large bodies of information.•The management of data involves both the definition of structures for the storage of information and the provision of mechanisms forthe manipulation of information.• A database-management system (DBMS) consists of a collection of interrelated data and a set of programs to access those data.•The primary goal of a DBMS is to provide an environment that is both convenient and efficient to use in retrieving and storing database information.Transaction Management• A transaction is a collection of operations that performs a single logical function in a database application. Each transaction is a unit of both atomicity and consistency.•Thus, we require that transactions do not violate any database-consistency constraints.•In the absence of failures, all transactions complete successfully, and atomicity is achieved easily.Storage Management•Database typically require a large amount of storage space.•Corporate databases are usually measured in terms of gigabytes or, for the largest databases, terabytes of data.•The performance of a system depends on what the efficiency is of the data structures used to represent the data in the database, and on how efficiently the system is able to operate on these data structures.Database Administrator•The person who has such central control over the system is called the database administrator (DBA).•The DBA creates the original database schema by writing a set of definitions that is translated by the DDL compiler to a set of tables that is stored permanently in the data dictionary.•The DBA also creates appropriate storage structures and access methods by writing a set of definitions, which is translated by the data-storage and data-definition-language compiler.Today's Database Landscape•In addition to the development of the relational database model, two technologies led to the rapid growth of what are now called client/server database systems.•Because processing is split between client computers and a database server, this new breed of application was a radical change from mainframe-based application programming.•The second important technology was the local area network (LAN) and its integration into offices across the world.Distributed Database System•In a distributed database system, the database is stored on several computers.•The computers in a distributed system communicate with oneanother through various communication media, such as high-speed networks or telephone lines.•The computers in a distributed system are referred to by a number of different names, such as sites or nodes, depending on the context in which they are mentioned.5.5 Computer Virus• A computer virus is a program designed to replicate and spread on its own, generally with the victim being oblivious to its existence.•Computer viruses spread by attaching themselves to other programs (e.g., word processor or spreadsheet application files) or to the boot sector of a disk.•Because a virus is software code, it can transmitted along with any legitimate software that enters your environment.•Nearly three-quarters (75 percent) of infections occurred in a networked environment, making rapid spread a serious risk. What’s the Features of Computer Virus?•Computer virus as a procedure can duplicate itself to other normal procedures or on some components of the system, for example, leading portion of disk.•The virus hidden in the infected system does not break out immediately; instead, it needs certain time or some conditionsbefore it breaks out.•Virus will begin attack once some conditions are ready.•Destruction caused by computer virus is extensive, it not only damages computer system, deletes files, or alters data, etc., it can also occupies system resources, disturb machine operation, etc.•Typically, virus can infect several thousand computers in several hours if the infected microcomputer is linked with Internet.•On one hand, new virus or their variations emerge with each passing day; on the other hand, some virus may resurrect after they have been eliminated, for example, when the infected floppy disk are reused.•Virus can transmit normal information as a carrier and thus avoid our protective measures set in the system.•Virus infects through various ways beyond our control, in addition, as illegal duplication and pirate software get popular, detection of virus becomes very difficult.•Virus tends to hide itself to avoid being detected.What’s the Structure of Computer Virus?•Infected sign is also called virus signature composed of ASCII code of some numbers or characters.•Infecting module performs three tasks: To search for an executable file or covered file, to check if there is infected sign on that file,and to infect it, write virus code into the host procedure, if no infected sign is found.•The virus designer attempts in the destructive code to delete files, delete data, format floppy disk and hard disk, decrease computer efficiency and space, etc.•If the condition is ready, the triggering module returns “true” value, and calls destroying module to destroy, otherwise it returns a “false” value.•Major control module controls the four modules mentioned above.Besides, it also ensures the infected program can continue to work normally and no deadlock will occur in contingency.What damage Can Viruses Do?•Some viruses are merely annoying, and others are disastrous.•At the very least, viruses expand file size and slow real-time interaction, hindering performance of your machine.•Other viruses are more dangerous.•They can continually modify or destroy data, intercept input/output devices, overwrite files and reformat hard disks.What Are the Symptoms of Virus Infection?•Changes in the length of programs•Changes in the file date or time stamp•Longer program load time•Slower system operation•Reduced memory or disk space•Bad sectors on your floppy•Unusual error messages•Unusual screen activity•Failed program execution•Failed system boot-ups when booting or accidentally booting from the A drive•Unexpected writes to a driveWhat Are the Effects of Computer Virus to the Society?•Some viruses create disgust effects or frighten the user, such as interfering the keyboard or displaying disgusting messages or pictures.•Computer viruses can be a great threat to a company. A company may lose important documents which may mean the lost of capital.•One step further, the operation breakdown of companies causes prelims to the society’s normal operation.。
计算机专业英语第5章
10
Notes
[1] Without a network, the documents have to be printed out so that others can edit them or use them. 译文：没有网络，就必须将文档打印出来才能供他 人编辑或使用。 本句的“Without a network”是条件状语，“so that” 引导的是目的状语从句。
（1）Star network （2）Grid network （3）Bus network （4）Ring network （5）Hybrid network
8
Key Words
accurate annulus backbone contractor diagnose fashion hierarchical hybrid merge neighbor
7
ห้องสมุดไป่ตู้he physical topology describes the layout of the network, just like a map shows the layout of various roads, and the logical topology describes how the data is sent across the network or how the cars are able to travel (the direction and speed) at every road on the map. Logical topology is the method used to pass the information between the computers.
《计算机专业英语》Unit 5 What is Operating System
The patterns are very diverse operating systems; OS can be installed on different machines from simple to complex, from the phone's embedded systems to large-scale supercomputer operating system. Many operating systems, the definition of manufacturer of the OS is not much consensus, for example, that some OS integrated graphical user interface, and some OS to use only a text interface, while the graphical interface as a non-essential applications.
资源, 财力, 办法, 智谋
经营, 管理, 处理, 操纵, 驾驶, 手段
Novell公司出的网络操作系统
植入的, 深入的, 内含的
计算机科学与技术专业英语：Chapter 05 THE SYSTEM UNIT
Computing Essentials 2017
System Board
☞System board or main board or motherboard controls
communication for the entire computer system
➢Arithmetic-logic unit (ALU)
◎ Performs arithmetic and logical operations
11
Computing Essentials 2017
Microprocessor Chips
☞Chip capacities are expressed in word size
➢Contained on a single chip call a Microprocessor ➢Brains of the computer
☞Two Basic Components of the CPU
➢Control unit
◎ Tells the computer system how to carry out a program’s instruction
◎ 3D images ◎ Encrypting data ◎ Standard features in gaming computers
Computing Essentials 2017
Memory
☞Holding area for data, instructions, and information ☞Contained on chips connected to the system board ☞Three well-known types of memory chips:
计算机专业英语 Chapter5
5.1 OS Function
New Words & Expressions: allocation n.分配 安置 分配, interface n.界面，接口 界面， 分配 界面 binding n. 捆绑，绑定 捆绑， mutual interference 相互干扰 entrust v.委托 criteria n.标准 委托 标准 constraint n.约束 强制 局促 partition vt.分区 约束, 约束 强制, 分区 apriori 预先 事前 预先,事前 perceive v.感知 感到 认识到 感知, 感知 感到, suboptimal adj.未达最佳标准的 preemption n.抢占 未达最佳标准的 抢占 sequential adj. 顺序的 串行的 concurrent adj.并发的 并行的 顺序的,串行的 并发的, 并发的 exclusive use 专用 de-allocate vt. 释放 scheduling n.调度 salient adj. 重要的，显著的 重要的， 调度
5.1.1 Resource allocation and related functions
Resource allocation criteria depend on whether a resource is a system resource or a user-created resource. Allocation of system resources is driven by considerations of efficiency of resource utilization. Allocation of user-created resources is based on a set of constraints specified by its creator and typically embodies the notion of access privileges. 资源分配的标准根据资源的分类确定， 资源分配的标准根据资源的分类确定，系统资源的分配要考虑 资源利用的效率， 资源利用的效率，而用户创立资源的分配则基于该资源的创立 者所设定的特种限制，比如访问权限。 者所设定的特种限制，比如访问权限。
计算机英语第五章
1 Programming Languages
03 Third-generation Languages
Third-generation languages are also known as procedural languages. They require that the program instructions tell the computer what to accomplish and how to do it.[3] They allow programs to be shorter and easier for the computer to read, but they require the programmer to design each procedure to be general enough to be used in different situations. Languages such as C, BASIC and FORTRAN are common procedural languages.
计算机英语
Chapter 5 Programming and Languages
1
目录
CONTENT
1
Programming Languages
2
Object-oriented Programming
3
Visual Programming
4 Web Programming
2
Lead in
A computer program is a sequence of instructions to perform a specified task by the computer. Computer programming is the act of writing these programs and the language used is called the programming language.
计算机专业英语Chapter 5 Computer Application
Ⅱ.Components of a GIS
A working GIS integrates five key components: hardware, software, data, people, and methods. 1.Hardware Hardware is the computer on which a GIS operates. Today, GIS software runs on a wide range of hardware types, from centralized computer servers to desktop computers used in stand-alone or networked configurations.
Chapter 5 Computer Application
Whether siting a new business, finding the best soil for growing bananas, or figuring out the best route for an emergency vehicle, local problems also have a geographical component. GIS will give you the power to create maps, integrate information, visualize scenarios, solve complicated problems, present powerful ideas, and develop effective solutions like never before. GIS is a tool used by individuals and organizations, schools, governments, and businesses seeking innovative ways to solve their problems.
计算机英语第五章
natural language processing: to enable it to communicate successfully in English; knowledge representation: to store what it knows or hears; automated reasoning: to use the stored information to answer questions and to draw new conclusions; machine learning: to adapt to new circumstances and to detect and extrapolate[1] patterns. [1]extrapolate: v. 推断, 外推
Chapter 5 Introduction on Artificial Intelligence
Session 1. Whห้องสมุดไป่ตู้t is AI?
We have claimed that AI is exciting, but we have not said what it is. Definitions of artificial intelligence according to eight textbooks are shown in Figure 1. These definitions vary along two main dimensions. Roughly, the ones on top are concerned with thought processes and reasoning, whereas the ones on the bottom address behavior.
计算机专业英语5
翻译：一个能固定计算机电路板的金属或塑料框架．通常，电路板插入框架的槽中， 翻译：一个能固定计算机电路板的金属或塑料框架．通常，电路板插入框架的槽中， 并通过总线把电子线路互相链接起来． 并通过总线把电子线路互相链接起来．
1-new words: 2．大型主机 3．超级小型计算机 4．个人计算机 5．工作站 6．巨型计算机 7．小巨型计算机
Second : Word size
Second : the effect of word size
A computer’s word size affects its processing speed, memory capacity, precision, and cost. Reading page 90-91 1. processing speed 2. memory capacity 3. precision 4. cost
4．Microcomputer architecture ．
Single-bus architecture
1. Why Microcomputers are sold to individuals, often to computer novices. 2. How Motherboard and interface
Main frame Super minicomputer Personal computer Work station Supercomputer Mini supercomputer
2-please remember to the technical terms
1. bus lines 总线 Bus lines, such as the ribbon-like set of parallel wires, link the computer’s internal components and are used to attach secondary storage devices to the system. 翻译：总线就像一组带状的并行线，用它链接计算机内部的部件，辅助存储 翻译：总线就像一组带状的并行线，用它链接计算机内部的部件， 器与系统的连接也使用这种线． 器与系统的连接也使用这种线． 2. word size 字长 A computer’s word size affects its processing speed, memory capacity, precision, and cost. 翻译：计算机的字长影响了它的速度、存储器的容量、精度和成本。 翻译：计算机的字长影响了它的速度、存储器的容量、精度和成本。
计算机专业英语Unit5
Section 2 Passages
Section 3 Skill in Focus
•
Section 4 Extended Reading
Unit 5 Programming Language
Section 1 Situational Dialogue
Requirements Analysis 1、你知道什么是软件工程吗？ 2、谈谈需求分析在软件工程中的作用。
Unit 5 Section 1
•
Qian Liang is asking Mr. Wu about software development. Qian Liang: Excuse me, Mr. Wu. Would you please tell me something about requirements analysis in software engineering? Mr. Wu: Of course. The hardest part of building a software system is deciding what to develop, and the hardest conceptual work is to establish detailed technical requirements, including all the interfaces to users, to machines and to other software systems. Meanwhile, it is also the part that cripples the resulting systems if done wrong, so it is most difficult to rectify later. Qian Liang: That’s what I refer to as “requirements analysis”, isn’t it? My understanding is that so long as we spend enough time communicating, anything wrong might be warded off.
计算机专业英语5
Unit 5 Software Process Section ASoftware Process ModelsI. IntroductionA software process is a set of activities that leads to the production of a software product. These activities may involve the development of software from scratch(从零开始、白手起家) in a standard programming language like Java or C. Increasingly, however, new software is developed by extending and modifying existing systems and by configuring and integrating off-the-shelf software or system components.A software process model is an abstract representation of a software process. Each process model represents a process from a particular perspective, and thus provides only partial information about that process. This section introduces a number of very general process models (sometimes called process paradigms) and presents them from anarchitectural perspective. That is, we see the framework of the process but not the details of specific activities.These generic models are not definitive descriptions of software processes. Rather, they are abstractions of the process that can be used to explain different approaches to software development. You can think of them as process frameworks that may be extended and adapted to create more specific software engineering processes.The process models covered here are the waterfall model, evolutionary development and component-based software engineering. These three generic process models are widely used in current software engineering practice. They are not mutually exclusive and are often used together, especially for large systems development. Sub-systems within a larger system may be developed using different approaches. Therefore, although it is convenient to discuss these models separately,you should understand that, in practice, they are often combined.II. The Waterfall ModelThe first published model of the software development process was derived from（起源于）more general system engineering processes. This is illustrated in Figure 5A-1. Because of the cascade from one phase to another, this model is known as the waterfall model or software life cycle. The principal stages of the model map onto fundamental development activities:1. Requirements analysis and definition. The system's services, constraints and goals are established by consultation with system users. They are then defined in detail and serve as a system specification.2. System and software design. The systems design process partitions the requirements to either hardware or software systems. It establishes an overall system architecture. Software design involves identifying anddescribing the fundamental software system abstractions and their relationships.3. Implementation and unit testing. During this stage, the software design is realized as a set of programs or program units. Unit testing involves verifying that each unit meets its specification. |4. Integration and system testing. The individual program units or programs are integrated and tested as a complete system to ensure that the software requirements have been met. After testing, the software system is delivered to the customer.5. Operation and maintenance. Normally (although not necessarily) this is the longest life-cycle phase. The system is installed and put into practical use. Maintenance involves correcting errors which were not discovered in earlier stages of the life cycle, improving the implementation of system units and enhancing the system’s services as new requirements are discovered.In principle, the result of each phase is one or more documents that are approved. The following phase should not start until the previous phase has finished. In practice, these stages overlap and feed information to each other. During design, problems with requirements are identified; during coding design problems are found and so on. The software process is not a simple linear model but involves a sequence of iterations of the development activities.Because of the costs of producing and approving documents, iterations are costly and involve significant rework. Therefore, after a small number of iterations, it is normal to freeze parts of the development, such as the specification, and to continue with the later development stages. Problems are left for later resolution, ignored or programmed around. This premature freezing of requirements may mean that the system won't do what the user wants. It may also lead to badly structuredsystems as design problems are circumvented by implementation tricks.During the final life-cycle phase (operation and maintenance), the software is put into use. Errors and omissions in the original software requirements are discovered. Program and design errors emerge and the need for new functionality is identified. The system must therefore evolve to remain useful. Making these changes (software maintenance) may involve repeating previous process stages. The advantages of the waterfall model are that documentation is produced at each phase and that it fits with other engineering process models. Its major problem is its inflexible partitioning of the project into distinct stages. Commitments must be made at an early stage in the process, which makes it difficult to respond to changing customer requirements. Therefore, the waterfall model should only be used when the requirements are well understood and unlikely to change radicallyduring system development. However, the waterfall model reflects the type of process model used in other engineering projects. Consequently, software processes based on this approach are still used for software development, particularly when the software project is part of a larger systems engineering project.III. Evolutionary Development Evolutionary development is based on the idea of developing an initial implementation, exposing this to user comment and refining it through many versions until an adequate system has been developed (Figure 5A-2). Specification, development and validation activities are interleaved rather than separate, with rapid feedback across activities.There are two fundamental types of evolutionary development:1. Exploratory development where the objective of the process is to work with the customers to explore their requirements anddeliver a final system. The development starts with the parts of the system that are understood. The system evolves by adding new features proposed by the customer.2. Throwaway prototyping where the objective of the evolutionary development process is to understand the customer's requirements and hence develop a better requirements definition for the system. The prototype concentrates on experimenting with the customer requirements that are poorly understood.An evolutionary approach to software development is often more effective than the waterfall approach in producing systems that meet the immediate needs of customers. The advantage of a software process that is based on an evolutionary approach is that the specification can be developed incrementally. As users develop a better understanding of their problem, this can be reflected in the software system. However, from an engineering and management perspective, theevolutionary approach has two problems:1. The process is not visible. Managers need regular deliverables to measure progress. If systems are developed quickly, it is not cost-effective to produce documents that reflect every version of the system.2. Systems are often poorly structured. Continual change tends to corrupt the software structure. Incorporating software changes becomes increasingly difficult and costly.For small and medium-sized systems (up to 500,000 lines of code), the evolutionary approach may be the best approach to development. The problems of evolutionary development become particularly acute for large, complex, long-life-time systems, where different teams develop different parts of the system. It is difficult to establish a stable system architecture using this approach, which makes it hard to integrate contributions from the teams.For large systems, a mixed process is recommended which incorporates the best features of the waterfall and the evolutionary development models. This may involve developing a throwaway prototype using an evolutionary approach to resolve uncertainties in the system specification. You can then reimplement the system using a more structured approach. Parts of the system that are well understood can be specified and developed using a waterfall-based process. Other parts of the system, such as the user interface, which are difficult to specify in advance, should always be developed using an exploratory programming approach.IV. Component-Based Software EngineeringIn the majority of software projects, there is some software reuse. This usually happens informally when people working on the project know of designs or code which is similar to that required. They look for these,modify them as needed and incorporate them into their system. In the evolutionary approach, reuse is often essential for rapid system development.This informal reuse takes place irrespective of the development process that is used. However, in the last few years, an approach to software development called component-based software engineering (CBSE), which relies on reuse, has emerged and is becoming increasingly used.This reuse-oriented approach relies on a large base of reusable software components and some integrating framework for these components. Sometimes, these components are systems in their own right (COTS or commercial off-the-shelf systems) that may provide specific functionality such as text formatting or numeric calculation. The generic process model for CBSE is shown in Figure 5A-3.While the initial requirements specificationstage and the validation stage are comparable with other processes, the intermediate stages in a reuse-oriented process are different. These stages are:1. Component analysis. Given the requirements specification, a search is made for components to implement that specification. Usually, there is no exact match, and the components that may be used only provide some of the functionality required.2. Requirements modification. During this stage, the requirements are analyzed using information about the components that have been discovered. They are then modified to reflect the available components. Where modifications are impossible, the component analysis activity may be re-entered to search for alternative solutions.3. System design with reuse. During this phase, the framework of the system is designed or an existing framework is reused. The designers take into account the components that arereused and organize the framework to cater to this. Some new software may have to be designed if reusable components are not available.4. Development and integration. Software that cannot be externally procured is developed, and the components and COTS systems are integrated to create the new system. System integration, in this model, may be part of the development process rather than a separate activity.Component-based software engineering has the obvious advantage of reducing the amount of software to be developed and so reducing cost and risks. It usually also leads to faster delivery of the software. However, requirements compromises are inevitable and this may lead to a system that not meet the real needs of users. Furthermore, some control over the system evolution is lost as new versions of the reusable components are not under the control of the organization usingthem.。
计算机专业英语Unit05_SectionA_Software_Process_Models
II. The Waterfall Model
3. Implementation and unit testing. During this stage, the software design is realized as a set of programs or program units. Unit testing involves verifying that each unit meets its specification. 4. Integration and system testing. The individual program units or programs are integrated and tested as a complete system to ensure that the software requirements have been met. After testing, the software system is delivered to the customer.
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II. The Waterfall Model
1. Requirements analysis and definition. The system’s services, constraints and goals are established by consultation with system users. They are then defined in detail and serve as a system specification. 2. System and software design. The systems design process partitions the requirements to either hardware or software systems. It establishes an overall system architecture. Software design involves identifying and describing the fundamental software system abstractions and their relationships.
计算机专业英语Unit 5 Network
TCP/IP Protocol Suite Protocols-Continue
❖ DNS(Domain Name System): an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they're easier to remember.
Computer English
TCP/IP Protocol Suite Protocols-Continue ❖ SMTP (Simple Mail Transfer Protocol) is a TCP/IP protocol
used in sending and receiving e-mail. However, since it is limited in its ability to queue messages at the receiving end, it is usually used with one of two other protocols, POP3 or IMAP, that let the user save messages in a server mailbox and download them periodically from the server. In other words, users typically use a program that uses SMTP for sending email and either POP3 or IMAP for receiving e-mail. Examples: sendmail(Unix), Microsoft Exchange
计算机专业英语第五章
Memory capacity is also a function of word size. To access main memory, the processor must transmit over a bus the address of a desired instruction or data element. On a 32-bit machine, a 32-bit address can be transmitted. The biggest 32-bit number is roughly 4 billion in decimal terms; thus the processor can access as many as 4 billion different memory locations. On the other hand, a 16-bit computer transmits a 16-bit address, limiting it to roughly 64,000 memory locations. Generally, the bigger its word size, the more main memory a computer can access. roughly 粗略地,大概
为代价逻辑地址段基址段内位移16位二进制16位二进制或4位16进制或4位16进制物理地址段基址左移一位16进制20位二进制数地址数可达220即1m
Chapter 5 – Linking the Components KEY CONCEPTS Micros and mainframes Bus lines and cables Word size Microcomputer architecture Mainframe architecture micros n. 微型机(相当于microcomputer) mainframes n. 主机,大型机 minicomputer n. 小型机 maxi n. 巨型机 supercomputer n. 超级计算机 word size n. 字长 bus n. 总线 architecture n. 体系结构
计算机专业英语Unit 5 Network
子网 企业内部网，一个公司内提供电 脑连通和因特网服务的系统 查证, 检验, 证实
许多的; 多路通讯的; 多样的
队列 尽力而为的服务，是一种标准的 因特网服务模式。 失去顺序
二进制表示
Computer English
New Words and Useful Expressions
dotted decimal notation byte-stream
❖ ICMP( Internet Control Message Protocol), an extension to the IP. ICMP supports packets containing error, control, and informational messages. The PING command, for example, uses ICMP to test an Internet connection.
TCP/IP Architecture & Mapping to OSI
OSI: Open Systems Interconnection
TCP/IP Computer English
TCP/IP Protocol Suite Protocols
❖ ARP(Address Resolution Protocol), a network layer protocol used to convert an IP address into a physical address, such as an Ethernet address
Computer English
Contents
1 2 3 4
Logo
TCP/IP Protocol Architecture IP TCP UDP
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计算机专业英语
》》
Lesson Two Transmission Control Protocol (TCP) The TCP provides reliable transmission of data in an IP environment. TCP corresponds to the transport layer (Layer 4) of the OSI reference model. Among the services TCP provides are stream data transfer, reliability, efficient flow control, full-duplex operation, and multiplexing.
计算机专业英语
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State of the art design tools Dreamweaver MX 2004 delivers powerful, standards-based controls to ensure high quality design. A design built around Cascading Style Sheets (CSS) enables faster and more efficient development of clean-coded, professional sites.
英语幽默笑话 Mosquitoes with Lanterns Two Scots was sleeping at a small hotel at New York. It was then the mosquito(蚊子) season. They had to spend the night defending themselves against the hungry mosquitoes. At last one of them said to the other, "Sandy, I have an idea, let us cover our heads with the quilts."
计算机专业英语
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TCP offers reliability by providing connection-oriented, end-to-end reliable packet delivery through an internet work. connection-oriented
计算机专业英语
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Lesson One Internet Protocols
Background The Internet protocols are the world's most popular opensystem (nonproprietary) protocol suite because they can be used to communicate across any set of interconnected networks and are equally well suited for LAN and WAN communications.
计算机专业英语
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计算机专业英语
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Internet Protocol (IP)
The Internet Protocol (IP) is a network-layer (Layer 3) protocol that contains addressing information and some control information that enables packets to be routed. network-layer address route
计算机专业英语
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After a time when Sandy put his head out to get a breath of fresh air, he saw a fire-fly(萤火虫)—he has never seen such an insect before. He shouted, "my friend, it's no use for us to cover our heads, they are coming with lanterns(灯笼) to look for us."
计算机专业英语
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Build sophisticated, standardsbased sites with rich CSS support. render intricate precisely selection style property
计算机专业英语
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Save time with a built-in graphics editor. crop resize Create better user interfaces without constant browser checks with a Live Data View that allows applications developers to see live server-side data while in design mode.
计算机专业英语
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With robust features for CSS-based design and integration, Dreamweaver enables web designers and developers to easily create and manage any website. code n.代码, 编码;v.编码 robust 精力充沛的 create 创造,创作,造成 Website 网站
计算机专业英语
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responsibility delivery datagram fragmentation reassembly link
n.责任,职责 传输,递送 数据包 分裂,破碎 重新组装
connectionless 无连接
n.连结物, 链接 vt.连结;vi.连接起来
maximum n.最大量, 极大 adj.最高的, 最多的, 最大极限的
计算机专业英语
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connection 连接 establishment 确立,制定 handshake 握手 mechanism 机制 synchronizes 同步 upon 在…之上 initial 最初的,初始的 sequence 次序,顺序
计算机专业英语
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This mechanism also guarantees that both sides are ready to transmit data and know that the other side is ready to transmit as well. This is necessary so that packets are not transmitted or retransmitted during session establishment or after session termination.
计算机专业英语
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Lesson Three Macromedia Dreamweaver MX 2004 Build professional web sites and applications Dreamweaver MX 2004 is the professional choice for building web sites and applications. Combination layout It provides a powerful combination of visual layout tools, application development features, and code editing support.
计算机专业英语
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protocol n.草案,协议 nonproprietary 开放性的 suite 套,组 across 越过,横过 interconnect 使互相连接 communication 信息,通讯 communicate 沟通
计算机专业英语
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The Internet protocols consist of a suite of communication protocols, of which the two best known are the Transmission Control Protocol (TCP) and the Internet Protocol (IP). Transmission Control Protocol 传输控制协议 Internet Protocol 网际协议
计算机专业英语
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英语口语练习材料
1.You are going to make it. 你准行! 你准行! 2.You are going to win. 你会赢! 你会赢! 3.You are my only hope. 你是我的希望. 你是我的希望. 4.You are almost there. Keep trying,stick to it. 你马上就要成功了,坚持,坚持下去! 你马上就要成功了,坚持,坚持下去! 5.You are the best. 你真是顶呱呱![这 你真是顶呱呱! 这 是母亲对儿子,女孩对男友常说的话. 是母亲对儿子,女孩对男友常说的话.] 68.You are fantastic. 你太棒了! 你太棒了!
网络层 地址 发送
计算机专业英语
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IP has two primary responsibilities: providing connectionless, best-effort delivery of datagrams through an internetwork; and providing fragmentation and reassembly of datagrams to support data links with different maximumtransmission unit (MTU) sizes.