有关计算机的论文英语作文怎么写
有关计算机的论文英语作文怎么写
With the development of the computer technology and the internet,we have got a new media to know the outside And our life is greatly changed with On the internet,you can get both the domestic news and the international news as For our daily communication, you can send E-mails to your friends and the other Of course,you can study whatever you like on the internet,such as, English and other Meanwhile,you can appreciate music,sports and enjoy the video Recently,more and more people,especially young people,are interested in shopping Anyway,internet is changing our style of life and the way of thinking as It is no doubt that computer and its internet play very important part in our life,study and On the computer,we can look for some new and fresh information so that we can study more And more and more people realize that we are in the non-paper That's to say we can do lots of things without paper like But meanwhile,some people,especially some young people are too addicted to the video games on the computer It is a waste of time and So,the question whether a computer is good or bad depends on how we use If we use it in a proper way,it will be very helpful to our life and
上面的是从百度知道哩搜的吧 小白 来看看哥给你写的 Computers are changing our life day by We can do many things on For example, we can write articles, do office work and play But the most important usage of computers is to get on the I We can do more things on the I We may do shopping, search information and communicate with people all around the In short,computers and Internet are making our life more and more
What do you think of computer?Computer is very useful for The Internet is a great facility for collecting The Internet makes it easy to build social we can have a lot of friends all over the world and reach much knowledge by I Millions of people communicate today through E-But the disadvantages of computer also have a The network information may be falsehood, so mach as leading to a wrong decision- May online socialization weaken our ability to deal with relationships in the real world? The weak-willed persons maybe indulge network-game and amusement in Internet thereby disrepair own The loveliness of Internet is infinitude and colorful, but strengthen to manage We make good use of it only while we have an appropriate approach to Internet
有关计算机的论文英语作文
REDUCED INSTRUCTION SET COMPUTERS Studies of the execution behavior of high-level language programs have provided guidance in designing a new type of processor architecture:the reduced instruction set computer(RISC).Assignment statements predominate,suggesting that the simple movement of data should be optimized.There are also many IF and LOOP instructions,which suggest that the underlying sequence control mechanism needs to be optimized to permit efficient pipelining.Studies of operand reference patterns suggest that it should be possible to enhance performance by keeping a moderate number of operands in registers. These studies have motivated the key characteristics of RISC machines:(1)a limited instruction set with a fixed format.(2)a large number of registers or the use of a compiler that optimizes register usage,and(3)an emphasis on optimizing the instruction pipeline. The simple instruction set of a RISC lends itself to efficient pipelining because there are fewer and more predictable operations performed per instruction.[1] A RISC instruction set architecture also lends itself to the delayed branch technique,in which branch instructions are rearranged with other instructions to improve pipeline efficiency. Although RISC systems have been defined and designed in a variety of ways by different groups,the key elements shared by most designs are these: .A large number of general-purpose registers,or the use of compiler technology to optimize register usage .A limited and simple instruction set .An emphasis on optimizing the instruction pipeline Table 2-1 compares several RISC and non-RISC 1.Instruction Execution Characteristics To understand the line of reasoning of the RISC advocates,we begin with a brief review of instruction execution characteristics.The aspects of computation of interest are as follows: • Operations performed:These determine the functions to be performed by the processor and its interaction with memory. • Operands used:The types of operands and the frequency of their use determine the memory organization for storing them and the addressing modes for accessing them. • Execution sequencing:This determines the control and pipeline organization. 2.The Use of A Large Register File [2] The reason that register storage is indicated is that it is the fastest available storage device,faster than both main memory and cache.The register file is physically small,generally on the same chip as the ALU and control unit,and employs much shorter addresses than addresses for cache and memory.Thus,a strategy is needed that will allow the most frequently accessed operands to be kept in registers and to minimize register-memory operations. Two basic approaches are possible,one based on software and the other on hardware.The software approach is to rely on the compiler to maximize register usage.The compiler will attempt to allocate registers to those variables that will be used the most in a given time period.This approach requires the use of sophisticated programanalysis algorithms.The hardware approach is simply to use more registers so that more variables can be held in registers for longer periods of time. 3.Characteristics of Reduced Instruction Set Architectures Although a variety of different approaches to reduced instruction set architecture have been taken,certain characteristics are common to all of them.These characteristics are listed in Table 2.1 and described here. The first characteristic listed in Table 2.1 is that there is one machine instruction per machine cycle.A machine cycle is defined to be the time it takes to fetch two operands from registers,perform an ALU operation,and store the result in a register.Thus,RISC machine instructions should be no more complicated than,and execute about as fast as,microinxtructions on CISC machines.[3] With simple,one –cycle instructions,there is little or no need for microcode;the machine instructions can be hardwired[4].Such instructions should execute faster than comparable machine instructions on other machines,since it is not necessary to access a microprogram control store during instruction execution. A second characteristic is that most operations should be register-to-register,with only simple LOAD and STORE operations accessing memory.This design feature simplifies the instruction set and therefore the control unit.For example,a RISC instruction set may include only one or two ADD instructions( ,integer add,add with carry);the VAX has 25 different ADD instructions.Another benefit is that such an architecture encourages the optimization of register use,so that frequently accessed operands remain in high-speed storage. Returning to Table 2-1,a third characteristic is the use of simple addressing modes.Almost all instructions use simple register addressing.Several additional modes,such as displacement and PC-relative,may be included.Other,more complex modes can be synthesized in software from the simple ones.Again,this design feature simplifies the instruction set and the control unit. A final common characteristic is the use of simple instruction formats.Generally,only one or a few formats are used.Instruction length is fixed and aligned on word boundaries.Field locations,especially the opcode,are fixed.This design feature has a number of benefits.With fixed fields,opcode decoding and register operand accessing can occur simultaneously.Simplified formats simplify the control unit.Instruction fetching is optimized since word-length units are fetched.This also means that a single instruction does not cross page boundaries. NOTES [1] lend itself to适合于… [2] register file寄存器组,作为数据或指令的临时存放处的一种多位寄存器组,有时称作栈。 [3] 此句为比较结构no than…,中间插入并列句将被比较对象隔开了。 [4] hardwired硬连线的,即机器指令是固化在硬件(芯片)上的。 KEYWORDS instruction set 指令系统,指令集 reduced instruction set computer(RISC) 精简指令系统计算机 pipeline 流水线 operand 操作数 register 寄存器 compiler 编译器,编译程序 branch instruction 转移指令,分支指令 Complex Instruction Set Computer(CISC) 复杂指令系统计算机 superscalar 超级标量 register file 寄存器组,栈 machine cycle 机器周期 microinstruction 微指令 microcode 微代码,微指令 nncroprogram 微程序 addressing 编址,寻址 精简指令系统计算机(RISC) 对高级语言程序执行性能的研究已经为设计新型处理器体系结构-一精简指令系统计算机提供了指南。赋值语句占据的优势表明应对单纯的数据传送进行优化。还有很多IF和LOOP指令存在,需要优化基本的顺序控制机构,以使流水线作业高效率。操作数引用模式的研究表明,在多个寄存器中保存适当数量的操作数,可以提高性能。 这些研究已经形成了RISC机的一些关键特性:(1)有限的固定格式的指令集;(2)使用大量的寄存器或使用编译器优化寄存器应用;(3)重点优化指令流水线。 因为每条指令完成少数的且多为可预测的操作,RISC的简单指令系统适合高效流水线作业。RISC指令系统体系结构也适合于延迟转移技术,在这种技术中,随同其他指令重新安排转移指令以提高流水线效率。 虽然RISC系统已经由不同的(企业)集团以各种方式进行了定义和设计,但大多数设计所提出的关键元素还是共同的。 用大量的通用寄存器(或使用编译器技术)来优化寄存器的使用; 有限的简单指令系统; 重点优化指令流水线作业。 表2-1比较了几种RISC和非RISC系统。 1.指令执行特性 为了解RISC倡导者们的推理思路,首先观察一下指令执行的一些特性。所要关心的计算特性如下所述。 所完成的操作:这些操作决定了处理器要完成的功能和处理器与存储器的交互 所用的操作数:操作数的类型和使用频度决定了存储操作数的存储机制和访问这些操作数的编址方式。 执行顺序:决定了控制和流水线的机制 2.大寄存器组的应用 使用寄存器存储的理由在于它是可用的最快的存储器件,比主存储器和高速缓存都快。寄存器组实际很小,通常与算术逻辑部件和控制器放在同一芯片上,而且使用比高速缓存和内存储器短很多的地址。因而需要一种允许最频繁访问的操作数保存在寄存器中并使寄存器-存储器操作降至最少的策略。 有两种可以采用的基本方法,一种基于软件,一种基于硬件。软件方法靠编译程序最大限度使用寄存器,编译程序力图将给定时间周期内最常用的那些变量分配到这些寄存器中。这一方法要求使用复杂的程序分析算法。硬件方法就是简单地使用更多的寄存器,使更多的变量保存在寄存器中供长时间使用。 3.精简指令系统体系结构的特性 尽管精简指令系统结构的可用方法有多种,但对它们而言有一些特性是共同的。这些特性列在表2-1中,下面进行解释。 表2-1中列出的第一个特性是每个机器周期有一条机器指令。一个机器周期定义为,机器从寄存器组中取出两个操作数,完成一种算术逻辑部件运算并将结果存入一个寄存器中所用的时间。RISC机器指令应该不比CISC机上的微指令复杂,并且执行起来也很快。因为简单,单周期指令仅需少量或不需要微代码;机器指令可以是硬连线的。这样指令执行起来比其他机器的类似机器指令要快,因为在指令执行期间它不必访问微程序控制存储器。 第二个特性是,大多数操作应该是寄存器对寄存器的,仅有简单的取(LOAD)和存(STORE)操作访问存储器。这种设计特点简化了指令系统,因而也简化了控制器。例如,一个RISC指令系统可以只包括一两种加法(ADD)指令〔例如整数加,进位加〕;VAX机则有25种不同的加法指令。另一好处是这种体系结构促进了对寄存器使用的优化,使得频繁访问的操作数保存在高速存储器中。 从表2-1还可看出第三个特性是采用简单的编址方式。几乎所有指令都采用简单的寄存器编址。几种附加的方式,如移位和与PC有关的方式可以包括进去。另外,更为复杂的方式可以用简单的方式在软件中合成。再次强调,这种设计特点简化了指令系统和控制器。 最后一个共同特性是采用简单的指令格式。一般来讲,只使用了一种或少数几种格式。指令长度是固定的并按字的边界调整。字段的位置,特别是操作码的位置是固定的。这种设计有很多优点,使用固定字段,操作码译码和寄存器操作数访问可同时进行。简化的格式简化了控制器;因为是按字长单位来读取的,所以,取指令也得到优化。这也表明一条指令不会跨页。
计算机专业英语一抄一大把~
The computer is a wonderful It has a lot of Today most computers have a That means information can be stored in it and be taken out any time So computers are used a great deal in many Computers are being made kinds of They can be used in doing business work smaller and cheaper while at the same time they have been made easier for Computers have worked faster and faster Computers can do many in science research work, in science of medicine, in some large factories; and even in our daily People also have been buying hone computers to plat computer games at They have become very popular
写好了汉字,在用金山词霸 翻译一下,就好了
与计算机有关的英语论文怎么写
Good Moring, ladies and gentlemen, Today my topic of my speech is the advantages and the disadvantages of In this information age/era, computer is very important in our everyday It definitely make our lives easier in many First of all, it helps us communicate with people all around the world, which means it not only save a lot of time when we have to send a message from one country to another, but also save a large of unnecessary troubles for Secondly, it gives many unemployed people chances to get a We can use computers and the Internet to sell and buy almost anything Last but not least, many wonderful games come along with the advent of And playing computer games is one of the most popular ways to entertain and to So, computers are really good for our human beings in many different However, every coin has two Computers also bring us many It gets across much unhealthy information and causes many But if we can use computer properly, it is still an amazing invention to Therefore, I hope that everyone, especially the young people, like me, can really appreciate the help of computers and make the best use of 很多的,我分次发~~~~~~~~~~~~~~~~~~~~
如何在不影响课程进度的前提下,省时而又有效地开展培养同学们的口语能力的活动,我有以下几点体会: ①Say something about your bedroon/school… 在学完一至两个单元后,可抽出一节课专门让同学们谈一 谈自己的卧室、学校或教室等等,这一口语活动在初一第一学期就可以做。为了让更多的学生都能参加,在此 之前可先复习一下小学学过的there be 句型以及“介词短语+be+名词”结构和“介词短语+you can see… ”结构。 这样做的好处是能有效让同学们根据这些句型轻松自然地描述出大脑里的图画。 ②Summary based on a dialogue 这一活动在初二就可以做。在这之前不妨先概括一下如下的句型结构: want/ask/tell sb (not) to dosth; want to do sth; ask if sb would like to do sth 以及一些简单句。 ③Text retelling 尽量用自己的语言口头改编、 复述较长的课文。在开展这一活动之前,允许同学们头一 天进行适当准备。不要限制同学们一定不要写提纲,甚至允许事先写出来。因为口头表达与书面表达是密切相联 的。只要同学们口头复述时不看书面提纲或内容即可。为了让全体同学有一个正确的标准,教师最好口头作一个 示范,让同学们有效地模仿。模仿在语言学习的初级阶段是相当重要的、不可缺少的步骤。 ④Make sentences 在平时的课堂教学中,当我们在学习一个新的词组和句型时,在给出典型的例句后, 应多多鼓励同学造句。同学们只要将例句看懂了都会非常乐意争先恐后地造句。有的句子甚至出乎意料的精彩 。这样做,不仅使同学们很轻松有效地学会了新词组、新句型,而且还为口语能力的形成打下了扎实的基础。 ⑤Debate/Argument 老师们可以根据学生学习的内容和实际水平,适当地选一个topic,让同学们展开争论。 如:Is it good or bad toplay video games in spare time? 还有在初二下学期学习情态动词can, ma y,must,can't时,就可给出一个model,让同学们模仿。如:给出一个实物让对方说出是什么: A What do you think it may be, B I think it may be an C It can't be an I think it must be a D How can it be a banana? A banana is long but it It must be an E It can't be an Anyone with eyes can see it isa…这样在模仿争论的同时,不知不觉中 掌握了情态动词的用法,从而也提高了同学们的口语表达能力。 ⑥Describe sb or sth you like best 随着一、二年级的知识积累,我们可以适当地让同学们在一节课的 前十分钟或后十分钟描述一下他(她)最喜欢的人或物。 以上只是我的个人观点,希望这些观点能让个同学们的口语有所提高。最后,祝住同学们都能学会英语,都能学懂英语,都能学好英语!
海外英语杂志欢迎投稿,详情见我的空间
_htm在里面找。,都是论文,大把。。。。
有关计算机的论文英语怎么说
The estimated costs of certain worm and virus instances are summarized in Table 表概述了某些蠕虫-病毒事件造成的大体经济损失Nearly all major worm or virus outbreaks have cost billions of 每次,严重蠕虫或病毒爆发时,所造成的经济损失几乎都有数十亿美元
Information literacy Knowing how to find data from several sources, select relevant material, analyse and organise it into a form that can be used to make Computers have become the tools people use to access and manage Information technologists are people who analyse and design the What is a computer? Tradition definitions of computers include • A machine that accepts data and processes it into use • A computer is a binary, digital, electronic, stored program • While a computer is commonly a digital machine, analogue machine do An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data (input), process data arithmetically and logically, produce results (output) from the processing and stores results for future Many computers receive and send data (communicate) across networks LAN and W A computer system consists of hardware and What is hardware? Hardware Hardware is physical devices or components that can be physically handled – you can thou Input Devices Input devices convert data that humans collect into coded electrical signals that a computer can The central processing unit The electronic processing takes place in the CPU The CPU consists of • A control unit that controls all of the computer’s functions and an • Arithmetic and logical unit (ALU) that performs any calculation Memory Memory holds all programs and What is RAM currently open? Data (notes) Word processor OS Output devices Output devices convert the computer’s electronic signals back into information Secondary storage devices These devices store programs and data The programs and data are not necessarily (or likely to be) in current E DVD CD Communication devices These devices enable a computer to connect to another List the six different type of hardware? Secondary storage(external), input, processor, output , memory, C Name eight pieces of hardware USB, keyboard, monitor, screen, RAM, ROM, VDU, M The system unit and peripheral devices The system unit is the computer Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the Peripheral devices include the key board, mouse, printer, joy stick and Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the Peripheral devices include the keyboard, mouse, printer, joy stick and What else does a computer have? Software Software is a computer program ,which is a detailed set of instructions that directs a computer to perform the tasks necessary to process data into These instructions are written in languages that computer can Software includes computer games, a word processing packing, an accounting package, amongst Definition of a computer system • A computer system is the configuration of hardware and software, functioning together, to process data into useful information, in order to achieve a purpose for a human What is data? • Data is raw facts, be they numbers, words, images and sounds, that can be input into a Mary a name is a piece of data What is information? • Information is processed data, that has meaning and is John is a list of names who scored an A grade on an exam John A Chai A Pam A Commodore $23 500 Magna $21 500 Falcon $19 800 The system unit contains the • Motherboard • CPU • Memory • Other electronics It is where the computer program instructions are executed and the data is manipulatedThe Processor CPU The CPU interprets and carries out basic instructions that operate the computer, the CPU contain the • Control unit and the • Arithmetic logic unit Control unit The control unit directs and coordinates the computer’s For every single instruction, the control unit repeats four basic operations, • Fetching • Decoding • Executing • Storing CPU speed The CPU’s speed may be measured in MIPS The number of millions of instructions per second Arithmetic/logic unit The ALU performs all calculations, which involve • Arithmetic operations 2+3 • Comparison operations age>=17 • Logical operations pass Processing instructions A CPU may begin executing a second machine cycle before completing the first-referred to as Current CPU’s can pipeline up to 4 Storage within the CPU Registers temporarily hold data and The computer’s clock A System clock is necessary to control the timing of all computer Each tick of the clock is referred to as a clock Clock speed is the speed at which a processor executes A hertz is one cycle per second and a megahertz is 1024 by1024 and a gigahertz is 1024 by 1024 Memory Memory is the temporary storage place for data and (program) Memory is measured in • Kilobytes 1024 bytes 2^10 • Megabytes 1024* 1024 bytes 2^20 • Gigabytes 1024*1024*1024 bytes 2^30 Representation of data Digital computers are built from many small electronic Each circuit, at any point of time can be turned OFF or ON Hence these devices are called two state Binary Digit 0and 1 Each off or on digital value is called a bit, short for binary A 1 bit computer would be able to distinguish between two values-characters, symbols or Hardly sufficient for the characters on the keyboard Bits Characters 1 2 2 4 3 8 4 16 5 32 6 64 7 128 8 256
Information literacy Knowing how to find data from several sources, select relevant material, analyse and organise it into a form that can be used to make Computers have become the tools people use to access and manage Information technologists are people who analyse and design the What is a computer? Tradition definitions of computers include �6�1 A machine that accepts data and processes it into use �6�1 A computer is a binary, digital, electronic, stored program �6�1 While a computer is commonly a digital machine, analogue machine do An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data (input), process data arithmetically and logically, produce results (output) from the processing and stores results for future Many computers receive and send data (communicate) across networks LAN and W A computer system consists of hardware and What is hardware? Hardware Hardware is physical devices or components that can be physically handled – you can thou Input Devices Input devices convert data that humans collect into coded electrical signals that a computer can The central processing unit The electronic processing takes place in the CPU The CPU consists of �6�1 A control unit that controls all of the computer’s functions and an �6�1 Arithmetic and logical unit (ALU) that performs any calculation Memory Memory holds all programs and What is RAM currently open? Data (notes) Word processor OS Output devices Output devices convert the computer’s electronic signals back into information Secondary storage devices These devices store programs and data The programs and data are not necessarily (or likely to be) in current E DVD CD Communication devices These devices enable a computer to connect to another List the six different type of hardware? Secondary storage(external), input, processor, output , memory, C Name eight pieces of hardware USB, keyboard, monitor, screen, RAM, ROM, VDU, M The system unit and peripheral devices The system unit is the computer Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the Peripheral devices include the key board, mouse, printer, joy stick and Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the Peripheral devices include the keyboard, mouse, printer, joy stick and What else does a computer have? Software Software is a computer program ,which is a detailed set of instructions that directs a computer to perform the tasks necessary to process data into These instructions are written in languages that computer can Software includes computer games, a word processing packing, an accounting package, amongst Definition of a computer system �6�1 A computer system is the configuration of hardware and software, functioning together, to process data into useful information, in order to achieve a purpose for a human What is data? �6�1 Data is raw facts, be they numbers, words, images and sounds, that can be input into a Mary a name is a piece of data What is information? �6�1 Information is processed data, that has meaning and is John is a list of names who scored an A grade on an exam John A Chai A Pam A Commodore $23 500 Magna $21 500 Falcon $19 800 The system unit contains the �6�1 Motherboard �6�1 CPU �6�1 Memory �6�1 Other electronics It is where the computer program instructions are executed and the data is manipulatedThe Processor CPU The CPU interprets and carries out basic instructions that operate the computer, the CPU contain the �6�1 Control unit and the �6�1 Arithmetic logic unit Control unit The control unit directs and coordinates the computer’s For every single instruction, the control unit repeats four basic operations, �6�1 Fetching �6�1 Decoding �6�1 Executing �6�1 Storing CPU speed The CPU’s speed may be measured in MIPS The number of millions of instructions per second Arithmetic/logic unit The ALU performs all calculations, which involve �6�1 Arithmetic operations 2+3 �6�1 Comparison operations age>=17 �6�1 Logical operations pass Processing instructions A CPU may begin executing a second machine cycle before completing the first-referred to as Current CPU’s can pipeline up to 4 Storage within the CPU Registers temporarily hold data and The computer’s clock A System clock is necessary to control the timing of all computer Each tick of the clock is referred to as a clock Clock speed is the speed at which a processor executes A hertz is one cycle per second and a megahertz is 1024 by1024 and a gigahertz is 1024 by 1024 Memory Memory is the temporary storage place for data and (program) Memory is measured in �6�1 Kilobytes 1024 bytes 2^10 �6�1 Megabytes 1024* 1024 bytes 2^20 �6�1 Gigabytes 1024*1024*1024 bytes 2^30 Representation of data Digital computers are built from many small electronic Each circuit, at any point of time can be turned OFF or ON Hence these devices are called two state Binary Digit 0and 1 Each off or on digital value is called a bit, short for binary A 1 bit computer would be able to distinguish between two values-characters, symbols or Hardly sufficient for the characters on the keyboard Bits Characters 1 2 2 4 3 8 4 16 5 32 6 64 7 128 8 256
海外英语杂志欢迎投稿,详情见我的空间
有关计算机的英语论文翻译怎么写
Information literacy Knowing how to find data from several sources, select relevant material, analyse and organise it into a form that can be used to make Computers have become the tools people use to access and manage Information technologists are people who analyse and design the What is a computer? Tradition definitions of computers include �6�1 A machine that accepts data and processes it into use �6�1 A computer is a binary, digital, electronic, stored program �6�1 While a computer is commonly a digital machine, analogue machine do An electronic device, operating under the control of instructions stored in its own memory unit, that can accept data (input), process data arithmetically and logically, produce results (output) from the processing and stores results for future Many computers receive and send data (communicate) across networks LAN and W A computer system consists of hardware and What is hardware? Hardware Hardware is physical devices or components that can be physically handled – you can thou Input Devices Input devices convert data that humans collect into coded electrical signals that a computer can The central processing unit The electronic processing takes place in the CPU The CPU consists of �6�1 A control unit that controls all of the computer’s functions and an �6�1 Arithmetic and logical unit (ALU) that performs any calculation Memory Memory holds all programs and What is RAM currently open? Data (notes) Word processor OS Output devices Output devices convert the computer’s electronic signals back into information Secondary storage devices These devices store programs and data The programs and data are not necessarily (or likely to be) in current E DVD CD Communication devices These devices enable a computer to connect to another List the six different type of hardware? Secondary storage(external), input, processor, output , memory, C Name eight pieces of hardware USB, keyboard, monitor, screen, RAM, ROM, VDU, M The system unit and peripheral devices The system unit is the computer Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the Peripheral devices include the key board, mouse, printer, joy stick and Peripheral devices are any devices around the outside, or in other words, plugged into the (back of) the Peripheral devices include the keyboard, mouse, printer, joy stick and What else does a computer have? Software Software is a computer program ,which is a detailed set of instructions that directs a computer to perform the tasks necessary to process data into These instructions are written in languages that computer can Software includes computer games, a word processing packing, an accounting package, amongst Definition of a computer system �6�1 A computer system is the configuration of hardware and software, functioning together, to process data into useful information, in order to achieve a purpose for a human What is data? �6�1 Data is raw facts, be they numbers, words, images and sounds, that can be input into a Mary a name is a piece of data What is information? �6�1 Information is processed data, that has meaning and is John is a list of names who scored an A grade on an exam John A Chai A Pam A Commodore $23 500 Magna $21 500 Falcon $19 800 The system unit contains the �6�1 Motherboard �6�1 CPU �6�1 Memory �6�1 Other electronics It is where the computer program instructions are executed and the data is manipulatedThe Processor CPU The CPU interprets and carries out basic instructions that operate the computer, the CPU contain the �6�1 Control unit and the �6�1 Arithmetic logic unit Control unit The control unit directs and coordinates the computer’s For every single instruction, the control unit repeats four basic operations, �6�1 Fetching �6�1 Decoding �6�1 Executing �6�1 Storing CPU speed The CPU’s speed may be measured in MIPS The number of millions of instructions per second Arithmetic/logic unit The ALU performs all calculations, which involve �6�1 Arithmetic operations 2+3 �6�1 Comparison operations age>=17 �6�1 Logical operations pass Processing instructions A CPU may begin executing a second machine cycle before completing the first-referred to as Current CPU’s can pipeline up to 4 Storage within the CPU Registers temporarily hold data and The computer’s clock A System clock is necessary to control the timing of all computer Each tick of the clock is referred to as a clock Clock speed is the speed at which a processor executes A hertz is one cycle per second and a megahertz is 1024 by1024 and a gigahertz is 1024 by 1024 Memory Memory is the temporary storage place for data and (program) Memory is measured in �6�1 Kilobytes 1024 bytes 2^10 �6�1 Megabytes 1024* 1024 bytes 2^20 �6�1 Gigabytes 1024*1024*1024 bytes 2^30 Representation of data Digital computers are built from many small electronic Each circuit, at any point of time can be turned OFF or ON Hence these devices are called two state Binary Digit 0and 1 Each off or on digital value is called a bit, short for binary A 1 bit computer would be able to distinguish between two values-characters, symbols or Hardly sufficient for the characters on the keyboard Bits Characters 1 2 2 4 3 8 4 16 5 32 6 64 7 128 8 256
The discussion about Network Security Technology [Abstract] With the increasingly extensive and in-depth of Computer Applicationat, computer and network security problems have become increasingly complex and prominent atthe same Network's vulnerability and complexity increased the possibility of threats and even With the global security incidents has risen over the years ,to ensure the safety of network information system has attracted the world's attention, and information security in all countries suffered from the unprecedented To do with network security, the paper-- from the firewall, attacks and emergency response, intrusion detection, hacker, and so on-- carried on a simple study[Key Word] Network, Firewall, Hacker, Internet
At the calculator apply increasingly and extensively with thorough of in the meantime, the safe problem of the calculator network is increasingly complicated with Flimsiness and complexity of network increased the possibility of threat and Increase year by year along with the global safe affairs, the safety which insures a network information system has already caused the concern of people of this world, the information safety all was subjected to an unprecedented value in all Lie this network safety, this text is from the fire wall, attackstone and meet an emergency to respond to, invade an examination, black guest what time carry on a simple
计算机发展及现状计算机网络是计算机技术和通信技术紧密结合的产物,它涉及到通信与计算机两个领域。它的诞生使计算机体系结构发生了巨大变化,在当今社会经济中起着非常重要的作用,它对人类社会的进步做出了巨大贡献。从某种意义上讲,计算机网络的发展水平不仅反映了一个国家的计算机科学和通信技术水平,而且已经成为衡量其国力及现代化程度的重要标志之一。自50年代开始,人们及各种组织机构使用计算机来管理他们的信息的速度迅速增长。早期,限于技术条件使得当时的计算机都非常庞大和非常昂贵,任何机构都不可能为雇员个人提供使用整个计算机,主机一定是共享的,它被用来存储和组织数据、集中控制和管理整个系统。所有用户都有连接系统的终端设备,将数据库录入到主机中处理,或者是将主机中的处理结果,通过集中控制的输出设备取出来。它最典型的特征是:通过主机系统形成大部分的通信流程,构成系统的所有通信协议都是系统专有的,大型主机在系统中占据着绝对的支配作用,所有控制和管理功能都是由主机来完成。随着计算机技术的不断发展,尤其是大量功能先进的个人计算机的问世,使得每一个人可以完全控制自己的计算机,进行他所希望的作业处理,以个人计算机(PC)方式呈现的计算能力发展成为独立的平台,导致了一种新的计算结构---分布式计算模式的诞生。一般来讲,计算机网络的发展可分为四个阶段:第一阶段:计算机技术与通信技术相结合,形成计算机网络的雏形;第二阶段:在计算机通信网络的基础上,完成网络体系结构与协议的研究,形成了计算机网络;第三阶段:在解决计算机连网与网络互连标准化问题的背景下,提出开放系统互连参考模型与协议,促进了符合国际标准的计算机网络技术的发展;第四阶段:计算机网络向互连、高速、智能化方向发展,并获得广泛的应用。任何一种新技术的出现都必须具备两个条件:即强烈的社会需求与先期技术的成熟。计算机网络技术的形成与发展也证实了这条规律。1946年世界上第一台电子数字计算机ENIAC在美国诞生时,计算机技术与通信技术并没有直接的联系。50年代初,由于美国军方的需要,美国半自动地面防空系统SAGE进行了计算机技术与通信技术相结合的尝试。要实现这样的目的,首先要完成数据通信技术的基础研究。在这项研究的基础上,人们完全可以将地理位置分散的多个终端通信线路连到一台中心计算机上。用户可以在自己的办公室内的终端键入程序,通过通信线路传送到中心计算机,人们把这种以单个为中心的联机系统称做面向终端的远程联机系统。它是计算机通信网络的一种。60年代初美国航空公司建成的由一台计算机与分布在全美国的2000多个终端组成的航空订票系统SABRE-1就是这种计算机通信网络。随着计算机应用的发展,出现了多台计算机互连的需求。这种需求主要来自军事、科学研究、地区与国家经济信息分析决策、大型企业经营管理。他们希望将分布在不同地点的计算机通过通信线路互连成为计算机-计算机网络。网络用户可以通过计算机使用本地计算机的软件、硬件与数据资源,也可以使用连网的其它地方计算机软件、硬件与数据资源,以达到计算机资源共享的目的。这一阶段研究的典型代表是美国国防部高级研究计划局(ARPA,Advanced Research Projects Agency)的ARPAnet(通常称为ARPA网)。1969年ARPA网只有4个结点,1973年发展到40个结点,1983年已经达到100多个结点。ARPA网通过有线、无线与卫星通信线路,使网络覆盖了从美国本土到欧洲与夏威夷的广阔地域。ARPR网是计算机网络技术发展的一个重要的里程碑,它对发展计算机网络技术的主要贡献表现在以下几个方面:1、完成了对计算机网络的定义、分类与子课题研究内容的描述;2、提出了资源子网、通信子网的两级网络结构的概念;3、研究了报文分组交换的数据交换方法;4、采用了层次结构的网络体系结构模型与协议体系。未来计算机与计算机技术计算机的要害技术继续发展 未来的计算机技术将向超高速、超小型、平行处理、智能化的方向发展。尽管受到物理极限的约束,采用硅芯片的计算机的核心部件CPU的性能还会持续增长。作为Moore定律驱动下成功企业的典范Inter预计2001年推出1亿个晶体管的微处理器,并预计在2010年推出集成10亿个晶体管的微处理器,其性能为10万MIPS(1000亿条指令/秒)。而每秒100万亿次的超级计算机将出现在本世纪初出现。超高速计算机将采用平行处理技术,使计算机系统同时执行多条指令或同时对多个数据进行处理,这是改进计算机结构、提高计算机运行速度的要害技术。 同时计算机将具备更多的智能成分,它将具有多种感知能力、一定的思考与判定能力及一定的自然语言能力。除了提供自然的输入手段(如语音输入、手写输入)外,让人能产生身临其境感觉的各种交互设备已经出现,虚拟现实技术是这一领域发展的集中体现。 传统的磁存储、光盘存储容量继续攀升,新的海量存储技术趋于成熟,新型的存储器每立方厘米存储容量可达10TB(以一本书30万字计,它可存储约1500万本书)。信息的永久存储也将成为现实,千年存储器正在研制中,这样的存储器可以抗干扰、抗高温、防震、防水、防腐蚀。如是,今日的大量文献可以原汁原味保存、并流芳百世。 新型计算机系统不断涌现 硅芯片技术的高速发展同时也意味着硅技术越来越近其物理极限,为此,世界各国的研究人员正在加紧研究开发新型计算机,计算机从体系结构的变革到器件与技术革命都要产生一次量的乃至质的飞跃。新型的量子计算机、光子计算机、生物计算机、纳米计算机等将会在21世纪走进我们的生活,遍布各个领域。Computer development and the present situationThe computer network is computer technology and communication technology in the combination of product, it involves communication and computer two Its birth make computer architecture, great changes have taken place in today's social economy plays a very important role, it to the progress of human society made great In a sense, the development of computer network level not only reflect a nation's computer science and communications technology level, and has become to measure its national strength and modernization degree one of the important Since the 1950s, people and start organizations use computer to manage their information speed rapid Early, limited to technical conditions such that computers are very large and very expensive, any agencies are not for personal use of the entire computer provide employees, host must be Shared, it is used to store and organize data, centralized control and management of the whole All customers have connection system of terminal equipment, will database into the host in processing, perhaps will host the deal, and through the centralized control output devices taken It is the most typical features are: the host system formed by most of the communication process, constitute a system all communication protocols are proprietary, mainframes in system occupies a absolute domination, all control and management functions are made by host to Along with the development of computer technology, especially large function of advanced of the personal computer was published, makes each one can fully control their own computer, he hoped assignments of treatment to personal computer (PC) non-ending computing power to become independent platform, causing a new calculation structure - distributed computing model was Generally speaking, the development of computer network can be divided into four stages:The first stage: the computer technology and communication technology should be combined to form the rudiment of computer network,The second stage: in computer communication network, on the basis of the complete network architecture and protocols research, forming a computer network,The third stage: in solving computer networking with network interconnection standardization, under the background of the reference model proposed open systems interconnection agreement, promoted the accord with international standard of the development of the computer network technology,Fourth step: computer network to the interconnection, high-speed and intelligent direction, and a wide range of A kind of any new technique appears must have two requirements: namely strong social demand and prior technology Computer network technology to the formation and development also confirmed this 1946 the world's first digital electronic computer ENIAC was born in the United States, computer technology and communication technology and no direct The early 50s, because the US military needs, American semi-automatic ground defense systems SAGE the computer technology and communication technology combining To achieve such a goal, we must first complete data communication technology of basic In this study, on the basis of one can completely will geographical position scattered multiple terminal communications lines connected to a central Users can in his office terminal type process through communication lines teleport to a central computer, people put this single center for online system oriented to the remote terminal called the online It is a kind of computer communication In the early 1960s American airlines built by a computer and distribution in the American more than 2000 terminals composed of airline reservation systems SABRE - 1 is this kind of computer communication Along with the development of computer application, appeared more computers interconnected This demand, mainly from the military, scientific research, regional and national economic information analysis and decision, large enterprise They hope will distribution in different locations through the computer communication lines to become computer - computer network Internet users can through computer USES the local computer hardware, software and data resources, also can use networking other parts of the computer software, hardware and data resources, in order to achieve the purpose of computer resources This one phase Research is the typical representative of by the us defense Advanced Research Projects Agency (ARPA on Projects Agency), true of the NCP (often called ARPA network) In 1969 ARPA nets only four nodes in 1973, development to 40 node, 1983 has reached more than 100 ARPA nets by wire, radio and satellite communication lines, network covers from native American to Europe and Hawaii's wide geographic ARPR net is computer network technology development of an important milestone, it to develop the main contribution of computer network technology performance in the following aspects:1, the completion of the computer network based on the definition, classification and research contents of description,2, puts forward a resource subnet, communication subnet two levels of network structure; the idea of3, study the message packet-switched data exchange method,4, adopts the hierarchical structure of network architecture model and protocol The future of computer and computer technologyComputer key technology continues to developThe future of computer technology to ultra-high speed, small-sized, parallel processing, intelligent In spite of physical limits of constraint by using silicon chips computer the core component of CPU performance will be sustained As Moore's law is driven by a successful business model Inter is expected to launch 100 million transistors in 2001 the microprocessor, and expected to launch in 2010 integrated one billion transistors microprocessor, its performance for 10 million the MIPS (1000 items of instruction/SEC) And 100 trillion times per second of the super computer will appear in the start of the Super-fast computers will adopts parallel processing technology, make the computer system and execute multiple instructions or simultaneously with multiple data processing, this is improved computer structure and improving computer running speed of key While the computer will have more intelligent composition, it will have a variety of perception, the certain thinking and judgement ability and a natural language In addition to providing natural input methods (such as speech input, handwritten input) outside, let a person can produce various delivered personally feeling