英文文献原文译文--Linux
1.1. History1.1.1. UNIXIn order to understand the popularity of Linux, we need to travel back in time, about 30 years ago...Imagine computers as big as houses, even stadiums. While the sizes of those computers posed substantial problems, there was one thing that made this even worse: every computer had a different operating system. Software was always customized to serve a specific purpose, and software for one given system didn't run on another system. Being able to work with one system didn't automatically mean that you could work with another. It was difficult, both for the users and the system administrators.Computers were extremely expensive then, and sacrifices had to be made even after the original purchase just to get the users to understand how they worked. The total cost of IT was enormous.Technologically the world was not quite that advanced, so they had to live with the size for another decade. In 1969, a team of developers in the Bell Labs laboratories started working on a solution for the software problem, to address these compatibility issues. They developed a new operating system, which wassimple and elegantwritten in the C programming language instead of in assembly codeable to recycle code.The Bell Labs developers named their project "UNIX."The code recycling features were very important. Until then, all commercially available computer systems were written in a code specifically developed for one system. UNIX on the other hand needed only a small piece of that special code, which is now commonly named the kernel. This kernel is the only piece of code that needs to be adapted for every specific system and forms the base of the UNIX system. The operating system and all other functions were built around this kernel and written in a higher programming language, C. This language was especially developed for creating the UNIX system. Using this new technique, it was much easier to develop an operating system that could run on many different types of hardware.The software vendors were quick to adapt, since they could sell ten times more software almost effortlessly. Weird new situations came in existence: imagine for instance computers from different vendors communicating in the same network, or users working on different systems without the need for extra education to use another computer. UNIX did a great deal to help users become compatible with different systems.Throughout the next couple of decades the development of UNIX continued. More things became possible to do and more hardware and software vendors added support for UNIX to their products. UNIX was initially found only in very large environments with mainframes and minicomputers (note that a PC is a "micro" computer). You had to work at a university, for the government or for large financial corporations in order to get your hands on a UNIX system.But smaller computers were being developed, and by the end of the 80's, many people had home computers. By that time, there were several versions of UNIX available for the PC architecture, but none of them were truly free.1.1.3. Current application of Linux systemsToday Linux has joined the desktop market. Linux developers concentrated on networking and services in the beginning, and office applications have been the last barrier to be taken down. We don't like to admit that Microsoft is ruling this market, so plenty of alternatives have been started over the last couple of years to make Linux an acceptable choice as a workstation, providing an easy user interface and MS compatible office applications like word processors, spreadsheets, presentations and the like.On the server side, Linux is well-known as a stable and reliable platform, providing database and trading services for companies like Amazon, the well-known online bookshop, US Post Office, the German army and such. Especially Internet providers and Internet service providers have grown fond of Linux as firewall, proxy- and web server, and you will find a Linux box within reach of every UNIX system administrator who appreciates a comfortable management station. Clusters of Linux machines are used in the creation of movies such as "Titanic" , "Shrek" and others. In post offices, they are the nerve centers that route mail and in large search engine, clusters are used to perform internet searches.These are only a few of the thousands of heavy-duty jobs that Linux is performing day-to-day across the world.It is also worth to note that modern Linux not only runs on workstations, mid- and high-end servers, but also on "gadgets" like PDA's, mobiles, a shipload of embedded applications and even on experimental wristwatches. This makes Linux the only operating system in the world covering such a wide range of hardware.1.2. The user interface1.2.1. Is Linux difficult?Whether Linux is difficult to learn depends on the person you're asking. Experienced UNIX users will say no, because Linux is an ideal operating system for power-users and programmers, because it has been and is being developed by such people.Everything a good programmer can wish for is available: compilers, libraries, development and debugging tools. These packages come with every standard Linux distribution. The C-compiler is included for free, all the documentation and manuals are there, and examples are often included to help you get started in no time. It feels like UNIX and switching between UNIX and Linux is a natural thing.In the early days of Linux, being an expert was kind of required to start using the system. . It was common practice to tell a beginning user to "RTFM" (read the manuals). While the manuals were on every system, it was difficult to find the documentation, and even if someone did, explanations were in such technical terms that the new user became easily discouraged from learning the system.The Linux-using community started to realize that if Linux was ever to be an important player on the operating system market, there had to be some serious changes in the accessibility of the system.1.2.2. Linux for non-experienced usersCompanies such as RedHat, SuSE and Mandrake have sprung up, providing packaged Linux distributions suitable for mass consumption. They integrated a great deal of graphical user interfaces (GUIs), developed by the community, in order to ease management of programs and services. As a Linux user today you have all the means of getting to know your system inside out, but it is no longer necessary to have that knowledge in order to make the system comply to your requests.Nowadays you can log in graphically and start all required applications without even having to type a single character, while you still have the ability to access the core of the system if needed. Because of its structure, Linux allows a user to grow into the system: it equally fits new and experienced users. New users are not forced to do difficult things, while experienced users are not forced to work in the same way they did when they first started learning Linux.While development in the service area continues, great things are being done for desktop users, generally considered as the group least likely to know how a system works. Developers of desktop applications are making incredible efforts to make the most beautiful desktops you've ever seen, or to make your Linux machine look just like your former MS Windows or MacIntosh workstation. The latest developments also include 3D acceleration support and support for USB devices, single-click updates of system and packages, and so on. Linux has these, and tries to present all available services in a logical form that ordinary people can understand.1.3. Does Linux have a future?1.3.1. Open SourceThe idea behind Open Source software is rather simple: when programmers can read, distribute and change code, the code will mature. People can adapt it, fix it, debug it, and they can do it at a speed that dwarfs the performance of software developers at conventional companies. This software will be more flexible and of a better quality than software that has been developed using the conventional channels, because more people have tested it in more different conditions than the closed software developer ever can.The Open Source initiative started to make this clear to the commercial world, and very slowly, commercial vendors are starting to see the point. While lots of academics and technical people have already been convinced for 20 years now that this is the way to go, commercial vendors needed applications like the Internet to make them realize they can profit from Open Source. Now Linux has grown past the stage where it was almost exclusively an academic system, useful only to a handful of people with a technical background. Now Linux provides more than the operating system: there is an entire infrastructure supporting the chain of effort of creating an operating system, of making and testing programs for it, of bringing everything to the users, of supplying maintenance, updates and support and customizations, etcetera. Today, Linux is ready to accept the challenge of a fast-changing world.1.3.2. Ten years of experience at your serviceWhile Linux is probably the most well-known Open Source initiative, there is another project that contributed enormously to the popularity of the Linux operating system. This project is called SAMBA, and its achievement is the reverse engineering of the Server Message Block (SMB)/Common Internet File System (CIFS) protocol used for file- and print-serving on PC-related machines, natively supported by MS Windows NT and OS/2, and Linux. Packages are now available for almost every system and provide interconnection solutions in mixed environments using MS Windows protocols: Windows-compatible (up to and including Win2K) file- and print-servers. Maybe even more successful than the SAMBA project is the Apache HTTP server project. The server runs on UNIX, Windows NT and many other operating systems. Originally known as "A PAtCHy server" , based on existing code and a series of "patch files" , the name for the matured code deserves to be connoted with the native American tribe of the Apache, well-known for their superior skills in warfare strategy and inexhaustible endurance. Apache has been shown to be substantially faster, more stable and more feature-full than many other web servers. Apache is run on sites that get millions of visitors per day, and while no official support is provided by the developers, the Apache user community provides answers to all your questions. Commercial support is now being provided by a number of third parties.In the category of office applications, a choice of MS Office suite clones is available, ranging from partial to full implementations of the applications available on MS Windows workstations. These initiatives helped a great deal to make Linux acceptable for the desktop market, because the users don't need extra training to learn how to work with new systems. With the desktop comes the praise of the common users, and not only their praise, but also their specific requirements, which are growing more intricate and demanding by the day.The Open Source community, consisting largely of people who have been contributing for over half a decade, assures Linux' position as an important player on the desktop market as well as in general IT application. Paid employees and volunteers alike are working diligently so that Linux can maintain a position in the market. The more users, the more questions. The Open Source community makes sure answers keep coming, and watches the quality of the answers with a suspicious eye, resulting in ever more stability and accessibility.1.4. Properties of Linux1.4.1. Linux ProsA lot of the advantages of Linux are a consequence of Linux' origins, deeply rooted in UNIX, except for the first advantage, of course:Linux is free:As in free beer, they say. If you want to spend absolutely nothing, you don't even have to pay the price of a CD. Linux can be downloaded in its entirety from the Internet completely for free. No registration fees, no costs per user, free updates, and freely available source code in case you want to change the behavior of your system.Most of all, Linux is free as in free speech:The license commonly used is the GNU Public License (GPL). The license says that anybody who may want to do so, has the right to change Linux and eventually to redistribute a changed version, on the one condition that the code is still available after redistribution. In practice, you are free to grab a kernel image, for instance to add support for teletransportation machines or time travel and sell your new code, as long as your customers can still have a copy of that code.Linux is portable to any hardware platform:A vendor who wants to sell a new type of computer and who doesn't know what kind of OS his new machine will run (say the CPU in your car or washing machine), can take a Linux kernel and make it work on his hardware, because documentation related to this activity is freely available.Linux was made to keep on running:As with UNIX, a Linux system expects to run without rebooting all the time. That is why a lot of tasks are being executed at night or scheduled automatically for other calm moments, resulting in higher availability during busier periods and a more balanced use of the hardware. This property allows for Linux to be applicable also in environments where people don't have the time or the possibility to control their systems night and day.Linux is secure and versatile:The security model used in Linux is based on the UNIX idea of security, which is known to be robust and of proven quality. But Linux is not only fit for use as a fort against enemy attacks from the Internet: it will adapt equally to other situations, utilizing the same high standards for security. Your development machine or control station will be as secure as your firewall.Linux is scalable:From a Palmtop with 2 MB of memory to a petabyte storage cluster with hundreds of nodes: add or remove the appropriate packages and Linux fits all. You don't need a supercomputer anymore, because you can use Linux to do big things using the building blocks provided with the system. If you want to do little things, such as making an operating system for an embedded processor or just recycling your old 486, Linux will do that as well.The Linux OS and Linux applications have very short debug-times:Because Linux has been developed and tested by thousands of people, both errors and people to fix them are found very quickly. It often happens that there are only a couple of hours between discovery and fixing of a bug.1.4.2. Linux ConsThere are far too many different distributions:"Quot capites, tot rationes", as the Romans already said: the more people, the more opinions. At first glance, the amount of Linux distributions can be frightening, or ridiculous, depending on your point of view. But it also means that everyone will find what he or she needs. You don't need to be an expert to find a suitable release.When asked, generally every Linux user will say that the best distribution is the specific version he is using. So which one should you choose? Don't worry too much about that: all releases contain more or less the same set of basic packages. On top of the basics, special third party software is added making,for example, TurboLinux more suitable for the small and medium enterprise, RedHat for servers and SuSE for workstations. However, the differences are likely to be very superficial. The best strategy is to test a couple of distributions; unfortunately not everybody has the time for this. Luckily, there is plenty of advice on the subject of choosing your Linux. One place is LinuxJournal , which discusses hardware and support, among many other subjects. The Installation HOWTO also discusses choosing your distribution.Linux is not very user friendly and confusing for beginners:In light of its popularity, considerable effort has been made to make Linux even easier to use, especially for new users. More information is being released daily, such as this guide, to help fill the gap for documentation available to users at all levels.Is an Open Source product trustworthy?How can something that is free also be reliable? Linux users have the choice whether to use Linux or not, which gives them an enormous advantage compared to users of proprietary software, who don't have that kind of freedom. After long periods of testing, most Linux users come to the conclusion that Linux is not only as good, but in many cases better and faster that the traditional solutions. If Linux were not trustworthy, it would have been long gone, never knowing the popularity it has now, with millions of users. Now users can influence their systems and share their remarks with the community, so the system gets better and better every day. It is a project that is never finished, that is true, but in an ever changing environment, Linux is also a project that continues to strive for perfection.1.1。
(完整word版)英文文献及翻译:计算机程序
姓名:刘峻霖班级:通信143班学号:2014101108Computer Language and ProgrammingI. IntroductionProgramming languages, in computer science, are the artificial languages used to write a sequence of instructions (a computer program) that can be run by a computer. Simi lar to natural languages, such as English, programming languages have a vocabulary, grammar, and syntax. However, natural languages are not suited for programming computers because they are ambiguous, meaning that their vocabulary and grammatical structure may be interpreted in multiple ways. The languages used to program computers must have simple logical structures, and the rules for their grammar, spelling, and punctuation must be precise.Programming languages vary greatly in their sophistication and in their degree of versatility. Some programming languages are written to address a particular kind of computing problem or for use on a particular model of computer system. For instance, programming languages such as FORTRAN and COBOL were written to solve certain general types of programming problems—FORTRAN for scientific applications, and COBOL for business applications. Although these languages were designed to address specific categories of computer problems, they are highly portable, meaning that the y may be used to program many types of computers. Other languages, such as machine languages, are designed to be used by one specific model of computer system, or even by one specific computer in certain research applications. The most commonly used progra mming languages are highly portable and can be used to effectively solve diverse types of computing problems. Languages like C, PASCAL and BASIC fall into this category.II. Language TypesProgramming languages can be classified as either low-level languages or high-level languages. Low-level programming languages, or machine languages, are the most basic type of programming languages and can be understood directly by a computer. Machine languages differ depending on the manufacturer and model of computer. High-level languages are programming languages that must first be translated into a machine language before they can be understood and processed by a computer. Examples of high-levellanguages are C, C++, PASCAL, and FORTRAN. Assembly languages are intermediate languages that are very close to machine languages and do not have the level of linguistic sophistication exhibited by other high-level languages, but must still be translated into machine language.1. Machine LanguagesIn machine languages, instructions are written as sequences of 1s and 0s, called bits, that a computer can understand directly. An instruction in machine language generally tells the computer four things: (1) where to find one or two numbers or simple pieces of data in the main computer memory (Random Access Memory, or RAM), (2) a simple operation to perform, such as adding the two numbers together, (3) where in the main memory to put the result of this simple operation, and (4) where to find the next instruction to perform. While all executable programs are eventually read by the computer in machine language, they are not all programmed in machine language. It is extremely difficult to program directly in machine language because the instructions are sequences of 1s and 0s. A typical instruction in a machine language might read 10010 1100 1011 and mean add the contents of storage register A to the contents of storage register B.2. High-Level LanguagesHigh-level languages are relatively sophisticated sets of statements utilizing word s and syntax from human language. They are more similar to normal human languages than assembly or machine languages and are therefore easier to use for writing complicated programs. These programming languages allow larger and more complicated programs to be developed faster. However, high-level languages must be translated into machine language by another program called a compiler before a computer can understand them. For this reason, programs written in a high-level language may take longer to execute and use up more memory than programs written in an assembly language.3. Assembly LanguagesComputer programmers use assembly languages to make machine-language programs easier to write. In an assembly language, each statement corresponds roughly to one machine language instruction. An assembly language statement is composed with the aid of easy to remember commands. The command to add the contents of the storage register A to the contents of storage register B might be written ADD B, A in a typical assembl ylanguage statement. Assembly languages share certain features with machine languages. For instance, it is possible to manipulate specific bits in both assembly and machine languages. Programmers use assemblylanguages when it is important to minimize the time it takes to run a program, because the translation from assembly language to machine language is relatively simple. Assembly languages are also used when some part of the computer has to be controlled directly, such as individual dots on a monitor or the flow of individual characters to a printer.III. Classification of High-Level LanguagesHigh-level languages are commonly classified as procedure-oriented, functional, object-oriented, or logic languages. The most common high-level languages today are procedure-oriented languages. In these languages, one or more related blocks of statements that perform some complete function are grouped together into a program module, or procedure, and given a name such as “procedure A.” If the same sequence of oper ations is needed elsewhere in the program, a simple statement can be used to refer back to the procedure. In essence, a procedure is just amini- program. A large program can be constructed by grouping together procedures that perform different tasks. Procedural languages 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 usedin different situations. Functional languages treat procedures like mathematical functions and allow them to be processed like any other data in a program. This allows a much higher and more rigorous level of program construction. Functional languages also allow variables—symbols for data that can be specified and changed by the user as the program is running—to be given values only once. This simplifies programming by reducing the need to be concerned with the exact order of statement execution, since a variable does not have to be redeclared , or restated, each time it is used in a program statement. Many of the ideas from functional languages have become key parts of many modern procedural languages. Object-oriented languages are outgrowths of functional languages. In object-oriented languages, the code used to write the program and the data processed by the program are grouped together into units called objects. Objects are further grouped into classes, which define the attributes objects must have. A simpleexample of a class is the class Book. Objects within this class might be No vel and Short Story. Objects also have certain functions associated with them, called methods. The computer accesses an object through the use of one of the object’s methods. The method performs some action to the data in the object and returns this value to the computer. Classes of objects can also be further grouped into hierarchies, in which objects of one class can inherit methods from another class. The structure provided in object-oriented languages makes them very useful for complicated programming tasks. Logic languages use logic as their mathematical base. A logic program consists of sets of facts and if-then rules, which specify how one set of facts may be deduced from others, for example: If the statement X is true, then the statement Y is false. In the execution of such a program, an input statement can be logically deduced from other statements in the program. Many artificial intelligence programs are written in such languages.IV. Language Structure and ComponentsProgramming languages use specific types of statements, or instructions, to provide functional structure to the program. A statement in a program is a basic sentence that expresses a simple idea—its purpose is to give the computer a basic instruction. Statements define the types of data allowed, how data are to be manipulated, and the ways that procedures and functions work. Programmers use statements to manipulate common components of programming languages, such as variables and macros (mini-programs within a program). Statements known as data declarations give names and properties to elements of a program called variables. Variables can be assigned different values within the program. The properties variables can have are called types, and they include such things as what possible values might be saved in the variables, how much numerical accuracy is to be used in the values, and how one variable may represent a collection of simpler values in an organized fashion, such as a table or array. In many programming languages, a key data type is a pointer. Variables that are pointers do not themselves have values; instead, they have information that the computer can use to locate some other variable—that is, they point to another variable. An expression is a piece of a statement that describe s a series of computations to be performed on some of the program’s variables, such as X+Y/Z, in which the variables are X, Y, and Z and the computations are addition and division. An assignment statement assigns a variable a value derived fromsome expression, while conditional statements specify expressions to be tested and then used to select which other statements should be executed next.Procedure and function statements define certain blocks of code as procedures or functions that can then be returned to later in the program. These statements also define the kinds of variables and parameters the programmer can choose and the type of value that the code will return when an expression accesses the procedure or function. Many programming languages also permit mini translation programs called macros. Macros translate segments of code that have been written in a language structure defined by the programmer into statements that the programming language understands.V. HistoryProgramming languages date back almost to the invention of the digital computer in the 1940s. The first assembly languages emerged in the late 1950s with the introduction of commercial computers. The first procedural languages were developed in the late 1950s to early 1960s: FORTRAN, created by John Backus, and then COBOL, created by Grace Hopper The first functional language was LISP, written by John McCarthy4 in the late 1950s. Although heavily updated, all three languages are still widely used today. In the late 1960s, the first object-oriented languages, such as SIMULA, emerged. Logic languages became well known in the mid 1970swith the introduction of PROLOG6, a language used to program artificial intelligence software. During the 1970s, procedural languages continued to develop with ALGOL, BASIC, PASCAL, C, and A d a SMALLTALK was a highly influential object-oriented language that led to the merging ofobject- oriented and procedural languages in C++ and more recently in JAVA10. Although pure logic languages have declined in popularity, variations have become vitally important in the form of relational languages for modern databases, such as SQL.计算机程序一、引言计算机程序是指导计算机执行某个功能或功能组合的一套指令。
英文文献整篇翻译
英文文献整篇翻译Title: The Impact of Climate Change on BiodiversityClimate change is a pressing issue that has significant impacts on biodiversity worldwide. Changes in temperature, precipitation patterns, and extreme weather events are altering ecosystems and threatening the survival of many species. The loss of biodiversity not only affects the natural world but also has implications for human societies.One of the major impacts of climate change onbiodiversity is the shifting of habitats. As temperatures rise, many species are forced to move to higher latitudesor elevations in search of suitable conditions. This can disrupt ecosystems and lead to the decline or extinction of species that are unable to adapt to the new conditions.In addition to habitat loss, climate change is also causing changes in the timing of biological events such as flowering, migration, and reproduction. These changes can disrupt the delicate balance of ecosystems and lead to mismatches between species that depend on each other for survival.Furthermore, climate change is exacerbating otherthreats to biodiversity such as habitat destruction, pollution, and overexploitation. The combination of these factors is putting immense pressure on many species and pushing them closer to extinction.It is essential that we take action to mitigate the impacts of climate change on biodiversity. This includes reducing greenhouse gas emissions, protecting and restoring habitats, and implementing conservation measures to safeguard vulnerable species. By addressing the root causes of climate change and protecting biodiversity, we canensure a sustainable future for both the natural world and human societies.气候变化对生物多样性的影响气候变化是一个紧迫的问题,对全球的生物多样性产生重大影响。
计算机英文文献加翻译
Management Information System Overview Management Information System is that we often say that the MIS, is a human, computers and other information can be composed of the collection, transmission, storage, maintenance and use of the system, system, emphasizing emphasizing the the management, management, management, stressed stressed stressed that that the modern information society In the increasingly popular. MIS is a new subject, it across a number of areas, such as scientific scientific management management management and and and system system system science, science, science, operations operations operations research, research, research, statistics statistics statistics and and and computer computer science. In these subjects on the basis of formation of information-gathering and processing methods, thereby forming a vertical and horizontal weaving, and systems. The 20th century, along with the vigorous development of the global economy, many economists have proposed a new management theory. In the 1950s, Simon made dependent on information management and decision-making ideas. Wiener published the same period of the control theory, that he is a management control process. 1958, Gail wrote: "The management will lower the cost of timely and accurate information to b etter control." During better control." During this period, accounting for the beginning of the computer, data processing in the term.1970, Walter T . Kenova just to the management information system under a definition of the . Kenova just to the management information system under a definition of the term: "verbal or written form, at the right time to managers, staff and outside staff for the past, present, the projection of future Enterprise and its environment-related information 原文请找腾讯3249114六,维^论~文.网 no no application application application model, model, model, no no mention mention of of computer applications. 1985, management information systems, the founder of the University of Minnesota professor of management at the Gordon B. Davis to a management information system a more complete definition of "management information system is a computer hardware and software resources, manual operations, analysis, planning , Control and decision -making model and the database - System. System. It It provides information to to support support enterprises enterprises or or organizations organizations of of the operation, management and decision-making function. "Comprehensive definition of this Explained Explained that that that the the the goal goal goal of of of management management management information information information system, system, system, functions functions functions and and and composition, composition, composition, but but also reflects the management information system at the time of level.With the continuous improvement of science and technology, computer science increasingly mature, the computer has to be our study and work on the run along. Today, computers are already already very low price, performance, but great progress, and it was used in many areas, the very low price, performance, but great progress, and it was used in many areas, the computer computer was was was so so so popular popular popular mainly mainly mainly because because because of of of the the the following following following aspects: aspects: aspects: First, First, First, the the the computer computer computer can can substitute for many of the complex Labor. Second, the computer can greatly enhance people's work work efficiency. efficiency. efficiency. Third, Third, Third, the the the computer computer computer can can can save save save a a a lot lot lot of of of resources. resources. resources. Fourth, Fourth, Fourth, the the the computer computer computer can can make sensitive documents more secure.Computer application and popularization of economic and social life in various fields. So that the original old management methods are not suited now more and social development. Many people still remain in the previous manual. This greatly hindered the economic development of mankind. mankind. In recent years, with the University of sponsoring scale is In recent years, with the University of sponsoring scale is growing, the number of students students in in in the the the school school school also also also have have have increased, increased, increased, resulting resulting resulting in in in educational educational educational administration administration administration is is is the the growing complexity of the heavy work, to spend a lot of manpower, material resources, and the existing management of student achievement levels are not high, People have been usin g the traditional method of document management student achievement, the management there are many shortcomings, such as: low efficiency, confidentiality of the poor, and Shijianyichang, will have a large number of of documents documents documents and and data, which is is useful useful for finding, finding, updating updating and maintaining Have brought a lot of difficulties. Such a mechanism has been unable to meet the development of the times, schools have become more and more day -to-day management of a bottleneck. bottleneck. In In In the the the information information information age age age this this this traditional traditional traditional management management management methods methods methods will will will inevitably inevitably inevitably be be computer-based information management replaced. As As part part part of of of the the the computer computer computer application, application, application, the the the use use use of of of computers computers computers to to to students students students student student student performance performance information for management, with a manual management of the incomparable advantages for example: example: rapid rapid rapid retrieval, retrieval, retrieval, to to to find find find convenient, convenient, convenient, high high high reliability reliability reliability and and and large large large capacity capacity capacity storage, storage, storage, the the confidentiality confidentiality of of of good, good, good, long long long life, life, life, cost cost cost Low. Low. Low. These These These advantages advantages advantages can can can greatly greatly greatly improve improve improve student student performance management students the efficiency of enterprises is also a scientific, standardized standardized management, management, management, and and and an an an important important important condition condition condition for for for connecting connecting connecting the the the world. world. world. Therefore, Therefore, the development of such a set of management software as it is very necessary thing.Design ideas are all for the sake of users, the interface nice, clear and simple operation as far as possible, but also as a practical operating system a good fault-tolerant, the user can misuse a timely manner as possible are given a warning, so that users timely correction . T o take full advantage advantage of the of the functions of visual FoxPro, design p owerful software powerful software at the same time, as much as possible to reduce the occupiers system resources. Visual FoxPro the command structure and working methods: Visual FoxPro was originally originally called called FoxBASE, FoxBASE, the the U.S. U.S. Fox Fox Software has introduced introduced a a database products, products, in in the run on DOS, compatible with the abase family. Fox Fox Software Software Microsoft acquisition, to be developed so that it can run on Windows, and changed its name to Visual FoxPro. Visual FoxPro is a powerful relational database rapid application development tool, tool, the the the use use use of of of Visual Visual Visual FoxPro FoxPro FoxPro can can can create create create a a a desktop desktop desktop database database database applications, applications, applications, client client client / / / server server applications applications and and and Web Web Web services services services component-based component-based component-based procedures, procedures, procedures, while while while also also also can can can use use use ActiveX ActiveX controls or API function, and so on Ways to expand the functions of Visual FoxPro.1651First, work methods 1. Interactive mode of operation (1) order operation VF in the order window, through an order from the keyboard input of all kinds of ways to complete the operation order. (2) menu operation VF use menus, windows, dialog to achieve the graphical interface features an interactive operation. (3) aid operation VF in the system provides a wide range of user-friendly operation of tools, such as the wizard, design, production, etc.. 2. Procedure means of implementation VF in the implementation of the procedures is to form a group of orders and programming language, an extension to save. PRG procedures in the document, and then run through the automatic implementation of this order documents and award results are displayed. Second, the structure of command 1. Command structure 2. VF orders are usually composed of two parts: The first part is the verb order, also known as keywords, for the operation of the designated order functions; second part of the order clause, for an order that the operation targets, operating conditions and other information . VF order form are as follows: 3. <Order verb> "<order clause>" 4. Order in the format agreed symbols 5. 5. VF in the order form and function of the use of the symbol of the unity agreement, the meaning of VF in the order form and function of the use of the symbol of the unity agreement, the meaning of these symbols are as follows: 6. Than that option, angle brackets within the parameters must be based on their format input parameters. 7. That may be options, put in brackets the parameters under specific requ ests from users choose to enter its parameters. 8. Third, the project manager 9. Create a method 10. command window: CREA T PROJECT <file name> T PROJECT <file name> 11. Project Manager 12. tab 13. All - can display and project management applications of all types of docume nts, "All" tab contains five of its right of the tab in its entirety . 14. Data - management application projects in various types of data files, databases, free form, view, query documents. 15. Documentation - display 原文请找腾讯原文请找腾讯3249114六,维^论~文.网 , statements, documents, labels and other documents. 16. Category - the tab display and project management applications used in the class library documents, including VF's class library system and the user's own design of the library. 17. Code - used in the project management procedures code documents, such as: program files (. PRG), API library and the use of project management for generation of applications (. APP). 18. (2) the work area 19. The project management work area is displayed and management of all types of document window. 20. (3) order button 21. Project Manager button to the right of the order of the work area of the document window to provide command. 22. 4, project management for the use of 23. 1. Order button function 24. New - in the work area window selected certain documents, with new orders button on the new document added to the project management window. 25. Add - can be used VF "file" menu under the "new" order and the "T ools" menu under the "Wizard" order to create the various independent paper added to the project manager, unified organization with management. 26. Laws - may amend the project has been in existence in the various documents, is still to use such documents to modify the design interface. 27. Sports - in the work area window to highlight a specific document, will run the paper.28. Mobile - to check the documents removed from the project. 29. 29. Even Even Even the the the series series series - - - put put put the the the item item item in in in the the the relevant relevant relevant documents documents documents and and and even even even into into into the the the application application executable file. Database System Design :Database design is the logical database design, according to a forthcoming data classification system and the logic of division-level organizations, is user-oriented. Database design needs of various departments of the integrated enterprise archive data and data needs analysis of the relationship between the various data, in accordance with the DBMS. 管理信息系统概要管理信息系统概要管理信息系统就是我们常说的MIS (Management Information System ),是一个由人、计算机等组成的能进行信息的收集、传送、储存、维护和使用的系统,在强调管理,强调信息的现代社会中它越来越得到普及。
外文参考文献译文及原文
目录1介绍 (1)在这一章对NS2的引入提供。
尤其是,关于NS2的安装信息是在第2章。
第3章介绍了NS2的目录和公约。
第4章介绍了在NS2仿真的主要步骤。
一个简单的仿真例子在第5章。
最后,在第.8章作总结。
2安装 (1)该组件的想法是明智的做法,以获取上述件和安装他们的个人。
此选项保存downloadingtime和大量内存空间。
但是,它可能是麻烦的初学者,因此只对有经验的用户推荐。
(2)安装一套ns2的all-in-one在unix-based系统 (2)安装一套ns2的all-in-one在Windows系统 (3)3目录和公约 (4)目录 (4)4运行ns2模拟 (6)ns2程序调用 (6)ns2模拟的主要步骤 (6)5一个仿真例子 (8)6总结 (12)1 Introduction (13)2 Installation (15)Installing an All-In-One NS2 Suite on Unix-Based Systems (15)Installing an All-In-One NS2 Suite on Windows-Based Systems (16)3 Directories and Convention (17)Directories and Convention (17)Convention (17)4 Running NS2 Simulation (20)NS2 Program Invocation (20)Main NS2 Simulation Steps (20)5 A Simulation Example (22)6 Summary (27)1介绍网络模拟器(一般叫作NS2)的版本,是证明了有用在学习通讯网络的动态本质的一个事件驱动的模仿工具。
模仿架线并且无线网络作用和协议(即寻址算法,TCP,UDP)使用NS2,可以完成。
一般来说,NS2提供用户以指定这样网络协议和模仿他们对应的行为方式。
linux专业实践报告参考文献
linux专业实践报告参考文献针对Linux专业实践报告的参考文献可以涵盖多个方面,包括Linux操作系统的基本原理、系统管理、网络配置、安全性等方面的内容。
以下是一些可能适用的参考文献:1. Tanenbaum, A. S., & Bos, H. (2014). Modern operating systems. Pearson Education.本书介绍了操作系统的基本原理和设计,对Linux操作系统的内核和功能有较为详细的介绍,适合用作Linux操作系统基础知识的参考。
2. Nemeth, E., Snyder, G., Hein, T., & Whaley, B. (2017). UNIX and Linux system administration handbook. Addison-Wesley Professional.该手册是系统管理员的权威指南,内容涵盖了Linux系统管理的方方面面,包括用户管理、文件系统、网络配置、安全性等,是Linux系统管理实践的重要参考资料。
3. Turner, M. (2016). Linux administration: Abeginner's guide. McGraw-Hill Education.本书适合初学者阅读,涵盖了Linux系统管理的基本概念和实践技巧,对于初次接触Linux系统管理的读者来说是一本很好的参考书籍。
4. Garrels, M. (2009). Introduction to Linux: A hands on guide.该书是一本开源的Linux操作系统指南,适合初学者学习Linux系统的基本操作和命令行技巧,对于Linux初学者来说是一本很好的参考资料。
5. Blum, R., & Bresnahan, C. (2015). Linux command line and shell scripting bible. John Wiley & Sons.本书介绍了Linux命令行和Shell脚本编程的基本知识和实践技巧,适合希望深入学习Linux命令行操作和脚本编程的读者阅读。
计算机专业外文文献翻译--Linux—网络时代的操作系统
英文参考文献及翻译Linux - Operating system of cybertimesThough for a lot of people , regard Linux as the main operating system to make up huge work station group, finish special effects of " Titanic " make , already can be regarded as and show talent fully. But for Linux, this only numerous news one of. Recently, the manufacturers concerned have announced that support the news of Linux to increase day by day, users' enthusiasm to Linux runs high unprecedentedly too. Then, Linux only have operating system not free more than on earth on 7 year this piece what glamour, get the favors of such numerous important software and hardware manufacturers as the masses of users and Orac le , Informix , HP , Sybase , Corel , Intel , Netscape , Dell ,etc. , OK?1.The background of Linux and characteristicLinux is a kind of " free (Free ) software ": What is called free,mean users can obtain the procedure and source code freely , and can use them freely , including revise or copy etc.. It is a result of cybertimes, numerous technical staff finish its research and development together through Inte rnet, countless user is it test and except fault , can add user expansion function that oneself make conveniently to participate in. As the most outstanding one in free software, Linux has characteristic of the following:(1)Totally follow POSLX standard, expand the network operatingsystem of supporting all AT&T and BSD Unix characteristic. Because of inheritting Unix outstanding design philosophy , and there are clean , stalwart , high-efficient and steady kernels, their all key codes are finished by Li nus Torvalds and other outstanding programmers, without any Unix code of AT&T or Berkeley, so Linu x is not Unix, but Linux and Unix are totally compatible.(2)Real many tasks, multi-user's system, the built-in networksupports, can be with such seamless links as NetWare , Windows NT , OS/2 , Unix ,etc.. Network in various kinds of Unix it tests to be fastest in comparing and assess efficiency. Support such many kinds of files systems as FAT16 , FAT32 , NTFS , Ex t2FS , ISO9600 ,etc. at the same time .(3) Can operate it in many kinds of hardwares platform , including such processors as Alpha , SunSparc , PowerPC , MIPS ,etc., to various kinds of new-type peripheral hardwares, can from distribute on global numerous programmer there getting support rapidly too.(4) To that the hardware requires lower, can obtain very good performance on more low-grade machine , what deserves particular mention is Linux outstanding stability , permitted " year " count often its running times.2.Main application of Linux At present,Now, the application of Linux mainly includes:(1) Internet/Intranet: This is one that Linux was used most at present, it can offer and include Web server , all such Inter net services as Ftp server , Gopher server , SMTP/POP3 mail server , Proxy/Cache server , DNS server ,etc.. Linux kernel supports IPalias , PPP and IPtunneling, these functions can be used for setting up fictitious host computer , fictitious service , VPN (fictitious special-purpose network ) ,etc.. Operating Apache Web server on Linux mainly, the occupation rate of market in 1998 is 49%, far exceeds the sum of such several big companies as Microsoft , Netscape ,etc..(2) Because Linux has outstanding networking ability , it can be usedin calculating distributedly large-scaly, for instance cartoon making , scientific caculation , database and file server ,etc..(3) As realization that is can under low platform fullness of Unix that operate , apply at all levels teaching and research work of universities and colleges extensively, if Mexico government announce middle and primary schools in the whole country dispose Linux and offer Internet service for student already.(4) Tabletop and handling official business appliedly. Application number of people of in this respect at present not so good as Windows of Microsoft far also, reason its lie in Lin ux quantity , desk-top of application software not so good as Windows application far not merely,because the characteristic of the freedom software makes it not almost have advertisement that support (though the function of Star Office is not second to MS Office at the same time, but there are actually few people knowing).3.Can Linux become a kind of major operating system?In the face of the pressure of coming from users that is strengthened day by day, more and more commercial companies transplant its application to Linux platform, comparatively important incident was as follows, in 1998 ①Compaq and HP determine to put forward user of requirement truss up Linux at their servers , IBM and Dell promise to offer customized Linux system to user too. ②Lotus announce, Notes the next edition include one special-purpose edition in Linux. ③Corel Company transplants its famous WordPerfect to on Linux, and free issue. Corel also plans to move the other figure pattern process products to Linux platform completely.④Main database producer: Sybase , Informix , Oracle , CA , IBM have already been transplanted one's own database products to on Linux, or has finished Beta edition, among them Oracle and Informix also offer technical support to their products.4.The gratifying one is, some farsighted domestic corporations have begun to try hard to change this kind of current situation already. Stone Co. not long ago is it invest a huge sum of money to claim , regard Linux as platform develop a Internet/Intranet solution, regard this as the core and launch Stone's system integration business , plan to set up nationwide Linux technical support organization at the same time , take the lead to promote the freedom software application and development in China. In addition domestic computer Company , person who win of China , devoted to Linux relevant software and hardware application of system popularize too. Is it to intensification that Linux know , will have more and more enterprises accede to the ranks that Linux will be used with domestic every enterprise to believe, more software will be planted in Linux platform. Meanwhile, the domestic university should regard Linux as the original version and upgrade already existing Unix content of courses , start with analysing the source code and revising the kernel and train a large number of senior Linux talents, improve our country's own operating system. Having only really grasped the operating system, the software industry of our country could be got rid of and aped sedulously at present, the passive state led by the nose byothers, create conditions for revitalizing the software industry of our country fundamentally.中文翻译Linux—网络时代的操作系统虽然对许多人来说,以Linux作为主要的操作系统组成庞大的工作站群,完成了《泰坦尼克号》的特技制作,已经算是出尽了风头。
计算机科学与技术 外文翻译 英文文献 中英对照
附件1:外文资料翻译译文大容量存储器由于计算机主存储器的易失性和容量的限制, 大多数的计算机都有附加的称为大容量存储系统的存储设备, 包括有磁盘、CD 和磁带。
相对于主存储器,大的容量储存系统的优点是易失性小,容量大,低成本, 并且在许多情况下, 为了归档的需要可以把储存介质从计算机上移开。
术语联机和脱机通常分别用于描述连接于和没有连接于计算机的设备。
联机意味着,设备或信息已经与计算机连接,计算机不需要人的干预,脱机意味着设备或信息与机器相连前需要人的干预,或许需要将这个设备接通电源,或许包含有该信息的介质需要插到某机械装置里。
大量储存器系统的主要缺点是他们典型地需要机械的运动因此需要较多的时间,因为主存储器的所有工作都由电子器件实现。
1. 磁盘今天,我们使用得最多的一种大量存储器是磁盘,在那里有薄的可以旋转的盘片,盘片上有磁介质以储存数据。
盘片的上面和(或)下面安装有读/写磁头,当盘片旋转时,每个磁头都遍历一圈,它被叫作磁道,围绕着磁盘的上下两个表面。
通过重新定位的读/写磁头,不同的同心圆磁道可以被访问。
通常,一个磁盘存储系统由若干个安装在同一根轴上的盘片组成,盘片之间有足够的距离,使得磁头可以在盘片之间滑动。
在一个磁盘中,所有的磁头是一起移动的。
因此,当磁头移动到新的位置时,新的一组磁道可以存取了。
每一组磁道称为一个柱面。
因为一个磁道能包含的信息可能比我们一次操作所需要得多,所以每个磁道划分成若干个弧区,称为扇区,记录在每个扇区上的信息是连续的二进制位串。
传统的磁盘上每个磁道分为同样数目的扇区,而每个扇区也包含同样数目的二进制位。
(所以,盘片中心的储存的二进制位的密度要比靠近盘片边缘的大)。
因此,一个磁盘存储器系统有许多个别的磁区, 每个扇区都可以作为独立的二进制位串存取,盘片表面上的磁道数目和每个磁道上的扇区数目对于不同的磁盘系统可能都不相同。
磁区大小一般是不超过几个KB; 512 个字节或1024 个字节。
毕业论文外文文献翻译
2013届本科生毕业论文英文参考文献翻译
Oracle虚拟机服务器软件虚拟化在一个64位
Linux环境的性能和可扩展性
(译文)
学院(系):
信息工程
专业年级:
学生姓名:
指导教师:
合作指导教师:
完成日期:
2013年6月
Oracle虚拟机服务器软件虚拟化在一个64位Linux环境的性能和可扩展性
benefits, however, this has not been without its attendantproblems and anomalies, such as performance tuning anderratic performance metrics, unresponsive virtualized systems,crashed virtualized servers, misconfigured virtual hostingplatforms, amongst others. The focus of this research was theanalysis of the performance of the Oracle VM servervirtualization platform against that of the bare-metal serverenvironment. The scalability and its support for high volumetransactions were also analyzed using 30 and 50 active usersfor the performance evaluation. Swingbench and LMbench,two open suite benchmark tools were utilized in measuringperformance. Scalability was also measured using Swingbench.Evidential results gathered from Swingbench revealed 4% and8% overhead for 30 and 50 active users respectively in theperformance evaluation of Oracle database in a single OracleVM. Correspondingly, performance metric法
计算机专业英语课文翻译
第4章操作系统第一部分阅读和翻译A部分 Windows 71. 简介Windows 7是微软最新发布的windows版本,这一系列微软制造的操作系统主要用于个人电脑,其中包括家庭和商业台式电脑、笔记本电脑、上网本、平板电脑、和媒体中心电脑。
(见图4.1)Windows 7于2009年7月22日开始生产,并在2009年10月22日零售,这个时间距其推出其前任Windows Vista不到三年时间。
与Windows 7相对应的Windows server 2008 R2,也是同年发布。
不像其前一操作系统vista,windows7 引入了大量的新特性,更集中于增量升级的windows线,目标是兼容已经在vista中兼容的应用程序和硬件。
微软在2008年的报告中关注于对于多点触控的支持,以及一个重新设计的windows shell和一个新的任务栏,并将其称之为Superbar,还有一个称之为家庭组的网络系统,注重性能改进。
之前版本的windows 系统中的一些标准的应用程序,包括windows日历,windows邮件,windows movie maker,和windows相片画廊在windows 7中并没有包含进来,而大多数是作为Windows Live Essentials套件单独免费进行提供的。
2. 发展最初,微软计划用一个代号为Blackcomb的windows版本来继承Windows XP(代号惠斯勒)和Windows Server 2003。
微软计划在Blackcomb中设计的主要功能包括在搜索中的加强,查询数据以及一个先进的存储命名系统。
然而,一个临时的,更小的,代号为Longhorn 的版本在2003年发布了。
微软在2003年中旬推迟发布了Blackcomb,但是Longhorn获得了大部分当初试图在Blackcomb中实现的特性。
在2003年,相继有三个主要病毒暴露了windows操作系统的一些漏洞,微软改变了其的发展重点,搁置了Longhorn的主要开发工作,主要开发windows xp和windows server 2003的服务包。
软件工程英文文献原文及翻译
英文文献原文及译文学生姓名:赵凡学号:1021010639学院:软件学院专业:软件工程指导教师:武敏顾晨昕2014年 6月英文文献原文The use of skinWhat is a skin? In the role of setting, the preparations made for the animation in the final process is skinning. The so-called skinning skinning tool is to use role-model role do with our skeletal system to help set the course together. After this procedure, fine role model can be rendered on real numbers can be made into animation. Bones in skinning process, in which the position is called Bind Pose. After the skin, bone deformation of the skin caused by the Games. However, sometimes inappropriate distortion, which requires bone or skin to make the appropriate changes, then you can make use of relevant command to restore the bone binding position, and then disconnect the association between bone and skin. In Maya, you can always put the bones and skin disconnected or reconnected. There is a direct way to skin the skin (skin flexible rigid skinning) and indirect skin (or wrap the lattice deformation of flexible or rigid skinning skinning joint use).In recent years, more and more 3D animation software, a great competition in the market, software companies are constantly developing and updating the relevant software only more humane, but in three-dimensional animation maya mainstream animation software. Able to create bone, meat, God's role is that each CG digital artists dream. Whether the digital characters charm, the test is the animator of life, understanding of life. Digital character to have bone and meat producers are required for the role of the body and has a full grasp of motor function. In addition, the roles of whether there is realism, the key lies in the design and production of the skin, which is skinning animation software for skilled technical and creative mastery is essential. Skin is ready to work in animation final steps, after this procedure, you can do the movements designed, if the skin did not do the work, after the animation trouble, so the skin is very important.As the three-dimensional animation with accuracy and authenticity, the current three-dimensional animation is rapidly developing country, nowadays the use ofthree-dimensional animation everywhere, the field of architecture, planning areas, landscape areas, product demonstrations, simulated animation, film animation, advertising, animation, character animation, virtual reality and other aspects of three-dimensional animation fully reflects the current importance. If compared to the three-dimensional animation puppet animation in real life, then the doll puppet animation equivalent of Maya modeling, puppet performers equivalent Maya animators and puppet steel joints in the body is the skeletal system. Bones in the animation will not be the final rendering, its role is only equivalent to a bracket that can simulate real bones set of major joints to move, rotate, etc.. When the bones are set, we will be bound to the skeleton model, this step is like a robot mounted to a variety of external parts, like hanging, and then through the various settings, add a keyframe animation on bone, and then drive to be bound by the bones corresponding to the model on the joints. Thus, in the final animation, you can see the stiffness of a stationary model with vitality. The whole process from the rigging point of view, may not compare more tedious keyframe animation, rigging, but it is the core of the whole three-dimensional animation, and soul.Rigging plays a vital role in a three-dimensional animation. Good rigging easy animation production, faster and more convenient allows designers to adjust the action figures. Each step are bound to affect the skeleton final animation, binding is based on the premise of doing animation, animators animate convenient, good binding can make animation more fluid, allowing the characters to life even more performance sex. In addition to rigging as well as expression of the binding character, but also to let people be able to speak or behave different facial expressions. Everything is done in order to bind the animation is set, it is bound to set a good animation is mainly based on the entire set of styles and processes. Rigging is an indispensable part in the three-dimensional animation.Three-dimensional animation production process: model, texture, binding, animation, rendering, special effects, synthesis. Each link is associated. Model and material determines the style of animation, binding, and animation determine fluency animation, rendering, animation effects, and synthetic colors and determine the finalresult.Three-dimensional animation, also known as 3D animation, is an emerging technology. Three-dimensional animation gives a three-dimensional realism, even subtle animal hair, this effect has been widely applied to the production of film and television in many areas, education, and medicine. Movie Crash, deformed or fantasy scenes are all three-dimensional animation in real life. Designers in the first three-dimensional animation software to create a virtual scene, and then create the model according to the proportion, according to the requirements set trajectory models, sports, and other parameters of the virtual camera animation, and finally as a model assigned a specific material, and marked the lights , the final output rendering, generating the final screen. DreamWorks' "Shrek" and Pixar's "Finding Nemo" is so accomplished visual impact than the two-dimensional animation has.Animated film "Finding Nemo" extensive use of maya scene technology. Produced 77,000 jellyfish animation regardless of the technical staff or artist is one of the most formidable challenge. This pink translucent jellyfish is most needed is patience and skill, you can say, jellyfish appeared animated sea creatures taken a big step. His skin technology can be very good. The use of film roles skinning techniques is very good, so that each character is vivid, is not related to expression, or action is so smooth, these underwater underwater world is so beautiful. Maya maya technology for the creation of the first to have a full understanding and knowledge. He first thought of creative freedom virtual capacity, but the use of technology has limitations. When the flexible skinning animation technique many roles in the smooth bound for editing, re-allocation tools needed to adjust the skeletal model for the control of the weight through the right point, every detail clownfish are very realistic soft. In the joint on the affected area should smear, let joints from other effects, this movement was not wearing a tie. Used less rigid, rigid lattice bound objects must be created in a position to help the bones of the joint motion. Animated film "Finding Nemo," the whole movie a lot of facial animation, facial skin but also a good technique to make facial expressions, the facial animation is also animated, and now more and more animated facial animationtechnology increasingly possible, these should be good early skin behind it will not affect the expression, there is therefore the creation of the film how maya digital technology, play his video works styling advantages and industrial processes are needed to explore creative personnel, all and three-dimensional figures on the production of content, from maya part. Two-dimensional hand-painted parts, post-synthesis of several parts, from a technical production, artistic pursuit. Several angles to capture the entire production cycle of creation. Maya techniques used in the animated film "Finding Nemo", the flexible skinning performance of many, clown face on with a lot of smooth binding, so more people-oriented, maya application of technical advantages in certain limited extent. Realistic three-dimensional imaging technology in the animation depth spatial density, the sense of space, mysterious underwater world to play the most. Because lifelike action, it also brings the inevitable footage and outdoor sports realistic density, but also to explore this movie maya main goal of the three-dimensional animation.英文文献译文蒙皮的运用什么是蒙皮?在角色设定中,为动画所作的准备工作里的最后一道工序就是蒙皮。
