5000字英文论文篇一：论文用5000字中英文翻译MCU DescriptionSCM is also known as micro-controller (Microcontroller Unit), commonly used letters of the acronym MCU that it was first used in industrial control. Only a single chip by the CPU chip developed from a dedicated processor. The first design is by a large number of peripherals and CPU on a chip in the computer system, smaller, more easily integrated into a complex and demanding on the volume control device which. INTEL s Z80 is the first designed in accordance with this idea processor, then on the development of microcontroller and dedicated processors have parted ways.Are 8-bit microcontroller early or 4 bits. One of the most successful is the INTEL 8031, for a simple, reliable and good performance was a lot of praise. Then developed in 8031 out of MCS51 MCU Systems. SCM systems based on this system until now are still widely used. With the increased requirements of industrial control field, began a 16-bit microcontroller, because the cost is not satisfactory but have not been very widely used. After 90 years with the great development of consumer electronics, microcontroller technology has been a huge increase. With INTEL i960 series, especially the later series of widely used ARM, 32-bit microcontroller quickly replace high-end 16-bit MCU status and enter the mainstream market. The traditional 8-bit microcontroller performances have been the rapid increase capacity increase compared to 80 the number of times. Currently, high-end 32-bit microcontroller clocked over 300MHz, the performance catching the mid-90 s dedicated processor, while the average model prices fall to one U.S. dollars; the most high-end model only 10 dollars. Modern SCM systems are no longer only in the developmentand use of bare metal environment, a large number of proprietary embedded operating system is widely used in the full range of SCM. The handheld computers and cell phones as the core processing of high-end microcontroller can even use a dedicated Windows and Linux operating systems.SCM is more suitable than the specific processor used in embedded systems, so it was up to the application. In fact the number of SCM is the world s largest computer. Modern human life used in almost every piece of electronic and mechanical products will be integrated single chip. Phone, telephone, calculator, home appliances,electronic toys, handheld computers and computer accessories such as a mouse with a 1-2 in both the Department of SCM. Personal computer will have a large number of SCM in the work. General car with more than 40 SCM, complex industrial control systems may even have hundreds of SCM in the same time work! SCM is not only far exceeds the number of PC and other computing the sum, or even more than the number of human beingsSingle chip, also known as single-chip microcontroller, it is not complete a certain logic chips, but to a computer system integrated into a chip. Equivalent to a micro-computer, and computer than just the lack of a microcontroller I / O devices. General talk: a chip becomes a computer. Its small size, light weight, cheap, for the study, application and development of facilities provided. At the same time, learning to use the MCU is to understand the principle and structure of the computer the best choice. SCM and the computer functions internally with similar modules, such as CPU, memory, parallel bus, the same effect as well, and hard disk memory devices, and different is its performance of these components were relatively weak many of our home computer, but the price is low , usually not more than 10 yuan you can do with it ...... some control for a class is not very complicated electrical work is enough of. We are usingautomatic drum washing machine, smoke hood, VCD and so on appliances which could see its shadow! ...... It is primarily as a control section of the core componentsIt is an online real-time control computer, control-line is that the scene is needed is a stronger anti-jamming ability, low cost, and this is, and off-line computer (such as home PC), the main difference.Single chipMCU is through running, and can be modified. Through different procedures to achieve different functions, in particular special unique features, this is another device much effort needs to be done, some great efforts are very difficult to do. A not very complex functions if the 50 s with the United States developed 74 series, or the 60 s CD4000 series of these pure hardware buttoned, then the circuit must be a large PCB board! But if the United States if the 70 s with a series of successful SCM market, theresult will be a drastic change! Just because you are prepared by microcomputer programs can achieve high intelligence, high efficiency and high reliability!As the microcontroller on the cost-sensitive, so now the dominant software or the lowest level assembly language, which is the lowest level in addition to more than binary machine code language, and as so low why is the use? Many high-level language has reached the level of visual programming Why is not it? The reason is simply that there is no home computer as a single chip CPU, not as hard as a mass storage device. A visualization of small high-level language program which even if only one button, will reach tens of K of size! For the home PC s hard drive in terms of nothing, but in terms of the MCU is not acceptable. SCM in the utilization of hardware resources to be very high for the job so although the original is still in the compilation of a lot of use. The same token,if the giant computer operating system and applications run up to get home PC, home PC, also can not afford to.Can be said that the twentieth century across the three power era, that is, the age of electricity, the electronic age and has entered into the computer age. However, this computer, usually refers to the personal computer, referred to as PC. It consists of the host, keyboard, monitor and other components. Another type of computer, most people do not know how. This computer is to give all kinds of intelligent machines single chip (also known as micro-controller). As the name suggests, this computer system took only a minimal integrated circuit, can be a simple operation and control. Because it is small, usually hidden in the charged mechanical stomach in. It is in the device, like the human brain plays a role, it goes wrong, the whole plant was paralyzed. Now, this microcontroller has a very broad field of use, such as smart meters, real-time industrial control, communications equipment, navigation systems, and household appliances. Once all kinds of products were using SCM, can serve to upgrade the effectiveness of products, often in the product name preceded by the adjective - intelligent, such as intelligent washing machines. Now some technical personnel of factories or other amateur electronics developers to engage in out of certain products, not the circuit is too complicated, that function is too simple and can easily be copied. The reason may be stuck in the product did not use a microcontrolleror other programmable logic device.SCM historySCM was born in the late 20th century, 70, experienced SCM, MCU, SoC three stages.First model1.SCM the single chip microcomputer (Single Chip Microcomputer) stage, mainly seeking the best of the best single form of embedded systemsarchitecture. Innovation model success, laying the SCM and general computer completely different path of development. In the open road of independent development of embedded systems, Intel Corporation contributed.2.MCU the micro-controller (Micro Controller Unit) stage, the main direction of technology development: expanding to meet the embedded applications, the target system requirements for the various peripheral circuits and interface circuits, highlight the object of intelligent control. It involves the areas associated with the object system, therefore, the development of MCU s responsibility inevitably falls on electrical, electronics manufacturers. From this point of view, Intel faded MCU development has its objective factors. In the development of MCU, the most famous manufacturers as the number of Philips Corporation. Philips company in embedded applications, its great advantage, the MCS-51 single-chip micro-computer from the rapid development of the micro-controller. Therefore, when we look back at the path of development of embedded systems, do not forget Intel and Philips in History.Embedded SystemsEmbedded system microcontroller is an independent development path, the MCU important factor in the development stage, is seeking applications to maximize the solution on the chip; Therefore, the development of dedicated single chip SoC trend of the natural form. As the microelectronics, IC design, EDA tools development, application system based on MCU SOC design have greater development. Therefore, the understanding of the microcontroller chip microcomputer can be, extended to the single-chip micro-controller applications.MCU applicationsSCM now permeate all areas of our lives, which is almost difficult to find traces of the field without SCM. Missile navigation equipment,aircraft, all types of instrument control, computer network communications and data transmission, industrial automation, real-time process control and data processing, extensive use of various smart IC card, civilian luxury car security system, video recorder, camera, fully automatic washing machine control, and program-controlled toys, electronic pet, etc., which are inseparable from the microcontroller. Not to mention the area of robot control, intelligent instruments, medical equipment was. Therefore, the MCU learning, development and application of the large number of computer applications and intelligent control of the scientists, engineers.SCM is widely used in instruments and meters, household appliances, medical equipment, aerospace, specialized equipment, intelligent management and process control fields, roughly divided into the following several areas:1. In the application of Intelligent InstrumentsSCM has a small size, low power consumption, controlling function, expansion flexibility, the advantages of miniaturization and ease of use, widely used instrument, combining different types of sensors can be realized Zhuru voltage, power, frequency, humidity, temperature, flow, speed, thickness, angle, length, hardness, elemental, physical pressure measurement. SCM makes use of digital instruments, intelligence, miniaturization, and functionality than electronic or digital circuits more powerful. Such as precision measuring equipment (power meter, oscilloscope, various analytical instrument).2. In the industrial control applicationWith the MCU can constitute a variety of control systems, data acquisition system. Such as factory assembly line of intelligent control 3. In Household AppliancesCan be said that the appliances are basically using SCM, praise from the electric rice, washing machines, refrigerators, air conditioners, color TV, and other audio video equipment, to the electronic weighing equipment, varied, and omnipresent.篇二：毕业论文5000字英文文献翻译(c++)┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 装┊ ┊ ┊ ┊ ┊ 订┊ ┊ ┊ ┊ ┊ 线┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊安徽工业大学毕业设计（论文）说明书英文翻译英语原文：. Introducing ClassesThe only remaining feature we need to understand before solving our bookstore problem is how to write a data structure to represent our transaction data. In C++ we define our own data structure by defining a class. The class mechanism is one of the most important features in C++. In fact, a primary focus of the design of C++ is to make it possible to define class types that behave as naturally as the built-in types themselves. The library types that we ve seen already, such as istream and ostream, are all defined as classesthat is,they are not strictly speaking part of the language.Complete understanding of the class mechanism requires mastering a lot of information. Fortunately, it is possible to use a class that someone else has written without knowing how to define a class ourselves. In this section, we ll describe a simple class that we canuse in solving our bookstore problem. We ll implement this class in the subsequent chapters as we learn more about types,expressions, statements, and functionsall of which are used in defining classes.To use a class we need to know three things:What is its name? Where is it defined?What operations does it support?For our bookstore problem, we ll assume that the class is named Sales_item and that it is defined in a header named Sales_item.h.The Sales_item ClassThe purpose of the Sales_item class is to store an ISBN and keep track of the number of copies sold, the revenue, and average sales price for that book. How these data are stored or computed is not our concern. To use a class, we need not know anything about how it is implemented. Instead, what we need to know is what operations the class provides.As we ve seen, when we use library facilities such as IO, we must include the associated headers. Similarly, for our own classes, we must make the definitions associated with the class available to the compiler. We do so in much the same way. Typically, we put the class definition into a file. Any program that wants to use our class must include that file. Conventionally, class types are stored in a file with a name that, like the name of a program source file, has two parts: a file name and a file suffix. Usually the file name is the same as the class defined in the header. The suffix usually is .h, but some programmers use .H, .hpp, or .hxx. Compilers usually aren t picky about header file names, but IDEs ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊┊ ┊ ┊ 装┊ ┊ ┊ ┊ ┊ 订┊ ┊ ┊ ┊ ┊ 线┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊安徽工业大学毕业设计（论文）说明书sometimes are. We ll assume that our class is defined in a file named Sales_item.h.Operations on Sales_item ObjectsEvery class defines a type. The type name is the same as the name of the class. Hence, our Sales_item class defines a type namedSales_item. As with the built-in types, we can define a variable of a class type. When we write Sales_item item we are saying that item is an object of type Sales_item. We often contract the phrase an object of type Sales_item to aSales_ item object or even more simply to a Sales_item. In addition to being able to define variables of type Sales_item, we can perform the following operations on Sales_item objects:Use the addition operator, +, to add two Sales_items,Use the input operator, to read a Sales_item object,Use the output operator, to write a Sales_item object,Use the assignment operator, =, to assign one Sales_item object to another,Call the same_isbn function to determine if two Sales_items refer to the same book.Classes are central to most C++ programs: Classes let us define our own types that are customizedfor the problems we need to solve, resulting in applications that are easier to write andunderstand.Well-designed class types can be as easy to use as the built-in types.A class defines data and function members: The data members store the state associated with objectsof the class type, and the functions perform operations that give meaning to the data. Classeslet us separate implementation and interface. The interface specifies the operations that the classsupports. Only the implementor of the class need know or care about the details of the implementation. This separation reduces the bookkeeping aspects that make programming tedious anderror-prone.Class types often are referred to as abstract data types. An abstract data type treats the data(state) and operations on that state as a single unit. We can think abstractly about what the classd oes, rather than always having to be aware of how the class operates. Abstract data types arefundamental to both object-oriented and generic programming.Data abstraction is a programming (and design) technique that relies on the separation of interfaceand implementation. The class designer must worry about how a class is implemented, but programmersthat use the class need not know about these details. Instead, programmers who use a type need to know only the type s interface; they can think abstractly about what the type does rather than concretely about how the type works. Encapsulation is a term that describes the technique of combining lower-level elements to forma new, higher-level entity. A function is one form of encapsulation: The detailed actions performedby the function are encapsulated in the larger entity that is the function itself. Encapsulated elements hide the details of their implementationwe may call ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 装┊ ┊ ┊ ┊ ┊ 订┊ ┊ ┊ ┊ ┊ 线┊ ┊ ┊ ┊┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊安徽工业大学毕业设计（论文）说明书a function but have no access to the statements that it executes. In the same way, a class is an encapsulated entity: It represents an aggregation of several members, and most (well-designed) class types hide the members that implement the type.If we think about the library vector type, it is an example of both data abstraction and encapsulation. It is abstract in that to use it, we think about its interfaceabout the operations that it can perform. It is encapsulated because we have no access to the details of how the type is representated nor to any of its implementation artifacts. An array, on the other hand, is similar in concept to a vector but is neither abstract nor encapsulated. We manipulate an array directly by accessing the memory in which the array is stored.Not all types need to be abstract. The library pair class is a good example of a useful, well-designed class that is concrete rather thanabstract. A concrete class is a class that exposes, rather than hides, its implementation.Some classes, such as pair, really have no abstract interface. The pair type exists to bundle two data members into a single object. There is no need or advantage to hiding the data members. Hiding the members in a class like pair would only complicate the use of the type.Even so, such types often have member functions. In particular, it is a good idea for any class that has data members of built-in or compound type to define constructor(s) to initialize those members. The user of the class could initialize or assign to the data members but it is less error-prone for the class to do so.Programmers tend to think about the people who will run their applications as users. Applicationsare designed for and evolve in response to feedback from those who ultimately use the applications. Classes are thought of in a similar way: A class designer designs and implements a class for users of that class. In this case, the user is a programmer, not the ultimate user of the application.Authors of successful applications do a good job of understanding and implementing the needs ofthe application s users. Similarly,well-designed, useful classes are designed with a close attention to the needs of the users of the class.In another way, the division between class designer and class user reflects the division betweenusers of an application and the designers and implementors of the application. Users care only if the application meets their needs in a cost-effective way. Similarly, users of a class care only about its interface. Good class designers define a class interface that is intuitive and easy to use. Users care about the implementation only in so far as the implementation affects their use of the class. If the implementation is too slow or puts burdens on users ofthe class, then the users must care. In well-designed classes, only the class designer worries about the implementation.In simple applications, the user of a class and the designer of the class might be one┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 装┊ ┊ ┊ ┊ ┊ 订┊ ┊ ┊ ┊ ┊ 线┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊安徽工业大学毕业设计（论文）说明书and the same person. Even in such cases, it is useful to keep the roles distinct. When designing the interface to a class, the class designer should think about how easy it will be to use the class. When using the class, the designer shouldn t think about how the class works.When referring to a user, the context makes it clear which kind of user is meant. If we speak of user code or the user of the Sales_item class, we mean a programmer who is using a class in writing an application. If we speak of the user of the bookstore application, we mean the manager of the store who is running the application.Data abstraction and encapsulation provide two important advantages: 1.Class internals are protected from inadvertent user-level errors, which might corrupt the state of the object.2.The class implementation may evolve over time in response to changing requirements or bug reports without requiring change inuser-level code.By defining data members only in the private section of the class, the class author is free to make changes in the data. If the implementation changes, only the class code needs to be examined to see what affect the change may have. If data are public, then any function that directly accesses the data members of the old representation might be broken. Itwould be necessary to locate and rewrite all those portions of code that relied on the old pesentation before the program could be used again. Similarly, if the internal state of the class is private, then changes to the member data can happen in only a limited number of places. The data is protected from mistakes that users might introduce. If there is a bug that corrupts the object s state, the places to look for the bug are localized: When data are private, only a member function could be responsible for the error. The search for the mistake is limited, greatly easing the problems of maintenance and program correctness.If the data are private and if the interface to the member functions does not change, then user functions that manipulate class objects require no change.Because changing a class definition in a header file effectively changes the text of every source file that includes that header, code that uses a class must be recompiled when the class changes.Classes are the most fundamental feature in C++. Classes let us define new types that are tailored to our own applications, making our programs shorter and easier to modify.Data abstractionthe ability to define both data and function membersand encapsulationthe ability to protect class members from general accessare fundamental to classes. Member functions define the interface to the class. We encapsulate the class by making the data and functions used by the implementation of a class private.Classes may define constructors, which are special member functions that control how┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ 装┊ ┊ ┊ ┊ ┊ 订┊ ┊ ┊ ┊ ┊ 线┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊ ┊安徽工业大学毕业设计（论文）说明书objects of the class are initialized. Constructors may be verloaded. Every constructor should initialize every data member. Constructors should use a constructor initializer list to initialize the data members. Initializer lists are lists of namevalue pairs where the name is a member and the value is an initial value for that member.Classes may grant access to their nonpublic members to other classes or functions. A class grants access by making the class or function a friend.Classes may also define mutable or static members. A mutable member is a data member that is never const; its value may be changed inside a const member function. A static member can be either function or data; static members exist independently of the objects of the class type. Copy ControlEach type, whether a built-in or class type, defines the meaning of a (possibly empty) set of operations on objects of that type. We can add two int values, run size on a vector, and so on. These operations define what can be done with objects of the given type.Each type also defines what happens when objects of the type are created. Initialization of objects of class type is defined by constructors. Types also control what happens when objects of the type are copied, assigned, or destroyed. Classes control these actions through special member functions: the copy constructor, the assignment operator, and the destructor. This chapter covers these operations.When we define a new type, we specifyexplicitly or implicitlywhat happens when objects of that type are copied, assigned, and destroyed. We do so by defining special members: the copy constructor, the assignment operator, and the destructor. If we do not explicitly define the copy constructor or the assignment operator, the compiler will (usually) define them for us.The copy constructor is a special constructor that has a single parameter that is a (usually const) reference to the class type. The copy constructor is used explicitly when we define a new object and initialize it from an object of the same type. It is used implicitly when we pass or return objects of that type to or from functions.Collectively, the copy constructor, assignment operator, and destructor are referred to as copy control. The compiler automatically implements these operations, but the class may define its own versions. Copy control is an essential part of defining any C++ class. Programmers new to C++ are often confused by having to define what happens when objects arecopied, assigned, or destroyed. This confusion is compounded because if we do not explicitly define these operations, the compiler defines them for usalthough they might not behave as we intend.Often the compiler-synthesized copy-control functions are finethey do exactly the篇三：毕业设计的5000字英文文献翻译外文及翻译英语原文 Android Application FundamentalsAndroid applications are written in the Java programming language. The Android SDK tools compile the code—along with any data and resource files—into an Android package, an archive file with an .apk suffix. All the code in a single .apk file is considered to be one application and is the file that Android-powered devices use to install the application. Once installed on a device, each Android application lives in its own security sandbox: ? The Android operating system is a multi-user Linux system in which eachapplication is a different user.? By default, the system assigns each application a unique Linux user ID (the ID is used only by the system and is unknown to the application). The system setspermissions for all the files in an application so that only the user ID assigned to that application can access them.? Each process has its own virtual machine (VM), so an application s code runs in isolation from other applications.? By default, every application runs in its own Linux process. Android starts the process when any of the application s components need to be executed, then shuts down the process when it s no longer needed or when the system must recovermemory for other applications.In this way, the Android system implements the principle of least privilege. That is, each application, by default, has access only to the components that it requires to do its work and no more. This creates a very secure environment in which an application cannot access parts of the system for which it is not given permission.However, there are ways for an application to share data with other applications and for an application to access system services:? It s possible to arrange for two applications to share the same Linux user ID, in whichcase they are able to access each other s files. To conserve system resources,applications with the same user ID can also arrange to run in the same Linux processand share the same VM (the applications must also be signed with the samecertificate).。
