电子信息工程外文翻译 外文文献 英文文献
电子信息工程 外文翻译 外文文献 英文文献 文献翻译
Technology and Application of Fieldbus Control System ---------IntelligentEquipment & Measurement And Control System Based on DeviceNetPromoted by the new technological revolution that automation control technology is tending digitization and internet in the field of automation industry, Shanghai Aton Electric Co., Ltd. developed Intelligent Equipment & Measurement And Control System Based on DeviceNet as a high and new technology industrialization model project. It was a state hi-tech development project of 2000 and was approved by the State Committee of Technology. Shanghai Aton Electric Co., Ltd. constructed production line of intelligent controller of pump and valve, relying on Shanghai Electric (Group) Corporation; constructed measurement and control system FCS R&D center of intelligent controller of pump and valve and built up mass production R&D basis, cooperating with Shanghai Jiaotong University and Shanghai University; constructed FCS remote diagnosis and service center of intelligent controller of pump and valve; constructed FCS training center of intelligent controller of pump and valve; founded mass production R&D basis along with the Rockwell Laboratory of Shanghai Jiaotong University and CIMS Center.1 Summary(1)Fieldbus control system is a system applied to field of production and microcomputerized measurement control equipment to realize both-way multinode serial communications. It is also called low-level control network for open, digital and multiplespot communications.Application: Flow Control System of Manufacturing; Process Control System; Traffic Control & Management; Building Automation. Features: Fieldbus control system is low-level low-bandwidth digital communication and control network in industrial system as well as open system connecting microcomputerized appearance. Intelligent instrument and controller are equal to microcomputer. They make up network with Fieldbus control system as the links to complete digital communication and other tasks.(2)Difference between FCS and DCS,FCS is updated control system after DCS integrated with digital control system and distributing control system. It solves the problem that in traditional DCS, devices made by different manufacturers cannot be connected. They can't realize exchange and operation to organize an network system with wider range of information sharing. It conquers the defect that special closed system for network should be used for communication in DCS to realize various functions of integrated automation. It turns the distributing structure combiningconcentration with deconcentration in DCS into new-type full distributing structure. It releases the control function to the field thoroughly and makes it possible to realize basic control function by means of fieldbus equipment itself. FCS breaks the traditional structure form of control system. The traditional analog control system adopts one-to-one equipment tie-wire and puts up connections respectively according to control loop. FCS adopts intelligent field equipment to place the control module, all input/output modules that used to be in the control chamber of DCS into field equipment. Since field equipment has ability to communicate, the field measuring and transferring instruments can transfer signals to actuating mechanism such as valve directly. Its control function can be fulfilled directly on the spot independent of the computer or control meter in the control chamber, which realizes thorough decentralized control.FCS adopts digital signals to replace analog signals so that multiple signals (including multiple operating parameter values, device status and failure information) can be transferred on a pair of cables. Meanwhile, it can give power supply to several devices. No switched block for analog/digital or digital/analog is needed besides fieldbus.(3)Characteristics of FCS●Open System;●Interoperability;● replace ability of devices made by different manufacturers.● Intelligentize and Autonomy;●Field equipment completing basic functions of automatic control.●Decentralized System Structure;●Field Adaptability;●Relatively Strong Interference Killing Feature and Safety●Intelligentized local equipment can save investment and quantity of hardware●Saving installation expenses and cables●Saving daily maintenance expenses●Enhancing accuracy and reliability of system●Enhancing initiativeness of system integration for users(4)Development Background and Trend of Fieldbus Control System,With the rapid development of computer and computer network, FCS has been rapidly developed as the interlinked communication network between the field intelligentdevices in the field of process automation, building and traffic etc. Because FCS meets the needs that industrial control system is developing in the way of decentralization, network and intellectualized, it has become the focus of global industrial automation and been universally concerned by the whole world. FCS has caused great revolutions on the aspects of system structure and function system for the current production of automation instrument, distributing control system and programmable controller. It is predicted that FCS will be the general trends in a very long time in the future fore sure.2 APPLICATION OF RELAYThe product reliability generally refers to the operating reliability. It is defined as: the ability of accomplishing the specified function under prescribed conditions and in prescribed time. It consists of intrinsic reliability and application reliability. The intrinsic reliability is determined by product designing and manufacturing technique, and the application reliability is concerned with the correct application of users and the services provided by the manufacturer before and after selling. When using relay, the user should pay attention to the following items.2.1 Coil applied voltageIt is best to choose the coil applicative voltage according to the rated voltage in design, or choose the voltage according to the temperature rising curve. Using any coil voltage that is less than the rated voltage will affect the operation of the relay. The coil operating voltage refers to the voltage that is applied between the coil terminals. The voltage value between the two terminals must be guaranteed, especially when using enlargement circuit to energize the coil. Whereas, it will also affect the relay characteristics if the applied voltage exceeds the highest rated voltage. Exorbitant voltage will bring exorbitant coil temperature rising, especially in high temperature ambient. Exorbitant temperature rising will damage the insulating material and affect the working safety of relay. For magnetic latching relay, energizing (or return) pulse width should not less than 3 times of the operating (or return) time, otherwise, the relay would be left on the middle-position state. When using solid-state components to energize the coil, the components dielectric strength must be above 80V, and the leakage of current must be as little as possible to ensure the relay to release.Energizing power source: Under 110% of the rated current, the adjusting ratio of the power source is less than 10% (or the output impedance is less than 5% of the coilimpedance), the wave voltage of the DC power source is less than 5%. The AC wave is sine wave; the waviness coefficient is between 0.95~1.25; wave distortion is within ±10%; the frequency change is within±1Hz or ±1% of the specified frequency (choosing the bigger value). The output power should not less than coil power consumption.2.2 Transient suppressionAt the moment when the coil power is stopped, peak-inverse voltage that is more than 30 times of the coil rated voltage is produced on the coil, which is harmful to the electronic circuit. Generally, the peak-inverse voltage is suppressed by transient suppression（cutting-peak）diode or resistance to limit the peak-inverse voltage within 50V. But the diode in parallel connection will delay3~5 times of the release time. If the request of the release time is high, a suitable resistance in series can be putted with and at one end of the diode.The power supply to relays in parallel connection and series connection,When several relays in parallel connection are supplied, the relay that the peak-inverse voltage is higher will release power to the relays that the peak-inverse voltage is lower. The release time of the relay will delay. So the relays in parallel connection should be controlled separately to eliminate mutual influence.The relays with different coil resistance and power can’t be used in series, otherwise, t he relay that the coil current is higher in the series circuit can’t operate reliably. Only the relays of the same specification can be used in series, but the peak-inverse voltage will be increased and the peak-inverse voltage should be suppressed. Resistance in series can be used to bear the part voltage that exceeds the rated voltage of the coil according to the ratio of the divided voltage.2.2.1 Contact loadThe load applied to the contacts should be accordant to the rated load and characteristics of the contacts. A load that is not applied according to the rated value range will cause problem. The relay that is only suitable for DC load can’t be used in AC occasions. The relay that can switch 10A load can’t always reliably operate in low level load (less than 10m A×6A) or in dry circuit occasions. The relay that can switch single-phase AC power source isn’t always suitable to switch two single-phase AC loads that aren’t synchronous; the relay that is only specif ied to switch the load of AC 50Hz（or 60Hz）can’t be used to switch AC load of 400Hz.2.2.2 Parallel and series connection of contactsThe contacts used in parallel connection can’t increase the load current, because the operating times of several sets of contacts are absolutely different; that is to say, there is still only a set of contacts switching the increased load. This would damage or weld the contacts and make the contacts can’t close or open. The parallel connection of the contacts can decrease t he misplay of “break”. But the parallel connection of the contacts would increase the misplay of “freezing”. Because the misplay of “break” is the main pattern of invalidation of contacts, the parallel connection can increase the reliability and can be used on the pivotal part of equipments. But the applied voltage should not exceed the highest operating voltage of the coil and should not less than 90% of the rated voltage, otherwise, the coil life and the applicative reliability would be damaged. The series connection of the contacts can increase the load voltage. The amount of the contact sets is equal to the times that the load voltage can be increased. The series connection of contacts can decrease the misplay of “freezing”, but it would increase the mis play of “break”. Anyway, when using redundant technology to increase the operating reliability of contacts, the characteristics and size and the failure mode of load must be considered.2.2.3 Switching speedThe switching speed should not exceed the reciprocal of 10 times of the sum of operating and release time (times/s), otherwise, the contacts can’t switch on steadily. Magnetic latching should be used under the pulse width specified in the technique criterion, or the coil may be damaged.3 RVT DISTRIBUTING ELECTRICITY INTEGRATE TESTAPPARATUSBasic functionMeasure asupervision:Three mutually electric voltage/electric current/ power factor with a great achievement/ power without a great achievement/electricity with a great achiverment/electricity/homophonic-wave electric voltage/ homophonic-wave electric/ current Day electric voltage/ electric current biggest and minimum value/fire for the failure Electric voltage over top, the limit/ lack mutually of time homophonic-wave analyzes is up to 13 times.The data is stored for 2 months.The data communicateRS232/485 communicating connect，The way in communicating can adopt the spot communicating or the long range communicating.，Possible to settle invoke orthe solid hour invokes, responding to the modification and long ranges control of the parameter.Without power compensationTaking physics measures as the power factor without a great achievement,the power factor with a great achievement and the dull place without power compensation;Y+ the combination method of the △，Y+ the △connects the line method，Y+ △ , Y, the △ connects the line method.Data managementAccording to WINDOW98 operation terrace, data in communication automatically reports born statement, curve and pillar form diagrams.Circulation of the protectionWhen the charged barbed wire net of mutually electric voltage over press, owe to press, and a super limit hour fast cut off in expiation of capacitor，When the charged barbed wire net lacks mutually or super limit in the preface of zero hour fast cut off in expiation of capacitor.screen manifestationChinese operation interface，Adopt 128*64 the back light liquid crystal display.The solid hour shows the charged barbed wire net relevant parameter.view manifestation to place the parameter.现场总线控制系统的技术和应用随着新的科学技术革命的出现，在自动化工业领域中，自动控制技术的发展趋向于数字化和网络互联化。
关于电子信息工程的英语作文
关于电子信息工程的英语作文English:Electronic information engineering is a discipline that combines electrical engineering and computer science to develop and design electronic devices and systems for the transmission, storage, processing, and access of information. It involves the study of various electronic components, digital systems, communication networks, and computer hardware and software. Electronic information engineering is an increasingly important field as our society becomes more reliant on technology, with applications ranging from telecommunications and radar systems to consumer electronics and healthcare devices. Graduates in this field are equipped with the necessary skills to work in a variety of industries, such as telecommunications, aerospace, automotive, and healthcare, where they can design, develop, and maintain electronic systems and devices.Translated content:电子信息工程是结合电气工程和计算机科学的学科，用于开发和设计用于信息传输、存储、处理和访问的电子设备和系统。
电子信息工程专业毕业论文中英文资料外文翻译文献
毕业论文毕业论文中英文对照翻译中英文对照翻译院（系部） 电气工程与自动化 专业名称 电子信息工程Infrared Remote Control SystemAbstractRed outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique,drive numerous hardware and software platform support. Red outside the transceiver product have cost low, small scaled turn, the baud rate be quick, point to point SSL, be free from electromagnetism thousand Raos etc.characteristics, can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission, at short distance wireless deliver aspect to own very obvious of advantage.Along with red outside the data deliver a technique more and more mature, the cost descend, red outside the transceiver necessarily will get at the short distance communication realm more extensive of application.The purpose that design this system is transmit customer’s operation information with infrared rays for transmit media, then demodulate original signal with receive circuit. It use coding chip to modulate signal and use decoding chip to demodulate signal. The coding chip is PT2262 and decoding chip is PT2272. Both chips are made in Taiwan. Main work principle is that we provide to input the information for the PT2262 with coding keyboard. The input information was coded by PT2262 and loading to high frequent load wave whose frequent is 38 kHz, then modulate infrared transmit dioxide and radiate space outside when it attian enough power. The receive circuit receive the signal and demodulate original information. The original signal was decoded by PT2272, so as to drive some circuit to accomplish customer’s operation demand.Keywords:Infrare dray；Code；Decoding；LM386；Redoutside transceiver1 Introduction1.1 research the background and significanceInfrared Data Communication Technology is the world wide use of a wireless connection technology, by the many hardware and software platforms supported. Is a data through electrical pulses and infrared optical pulse switch between the wireless data transceiver technology.Infrared transceiver products with low cost, small, fast transmission rate, the point-to-point transmission security, not subject to electromagnetic interference and other characteristics that can be achieved between the different products, rapid, convenient and safe exchange and transmission, In short distance wireless transmission have a very distinct advantage.Infrared transceiver products in the portable product of a great role. At present, the world's 150 million piece of equipment used infrared technology in electronic products and industrial equipment. medical equipment and other fields widely used. For example, 95% of the notebook computers on the installation of infrared transceiver interface the majority of the cell phone is also the allocation of infrared transceiver interface. With the exchange of quantitative data, infrared data communications will enable cell phone data transmission more convenient. With infrared data transmission technology matures, perfect, low costs, Infrared Transceiver in short distance communications will be more widely applied.This chapter first describes the infrared transceiver IC design issues to the background and significance. then briefed the infrared data communications technology features and applications, and infrared transceiver product characteristics, domestic and international situation and development trend of the last under infrared remote transceiver system in practical application to establish a task of design orientation.1.2 Infrared Remote ControlTransceiver SystemInfrared remote control system is divided into single-channel and multi-channel remote control. Only a command signal transmission channel, called single-channel remote control system; with more than two instructions signal transmission channel known as a multi-channel remote control system. Relatively simple single-channel remote control, in general, only a launcher directive Key receivers and only one circuit implementation. While in the receiving circuit to add more stable memory circuits that can be activated commands to launch a number of key, so that the receiver circuit multistable memory circuit repeatedly to change the state, to realize many of the functional control, But such a state of change is the order. If we are to achieve an arbitrary control, resort to the use of multi-channel remote control system. Multi-channel remote control can be realized by the object of arbitrary multi-function remote control. As for the choice of several routes and what control methods, according to the actual situation (such as object, operational requirements and cost accounting, etc.) to decide. General infrared remote transceiver system by infrared remote control transmitter signal coding, infrared remote control signal receivers and decoders (or decoder chip MCU) and the external circuit consisting of three parts. Signal transmitter remote control code used to generate pulses of infrared emission-driven output infrared remote control signal, receiver completion of the remote control signal amplification and detection, plastic and demodulation encoding pulse. Infrared remote control coded pulse is going to obtain a continuous serial binary code, and for most of the infrared transceiver system, This serial code as micro-controller of the remote control input signals from the internal CPU completion of the remote control instruction decoder, on the other infrared remote control transceivers, the designers of electronic products, The internal micro-controller of the remote control decoder directive is not accessible.Therefore, people are using infrared encoder / decoder chip and microcontroller developed various generic infrared remote transceiver system, In various equipment infrared signals between the transceiver.Remote transceiver system generally transmitters and receivers is composed of two parts. Launchers from the general direction keys, coded instructions circuit modulation circuit, driving circuit, firing circuit of several parts. When pressed a key, the directive coding circuit, in the corresponding instructions encoded signal, the encoder signal to the carrier modulation, Driven by the power amplifier circuit after circuit fired from the field after firing instructions coded modulation signals. General receiver by the receiving circuit, the amplifier circuit, demodulation circuits, instruction decoder circuit, driving circuit, circuit implementation of several parts. Receiving Circuit will launch vehicles have been coded modulation signal receiving instructions from, and to enlarge evacuation demodulation circuit. Demodulation circuit will have the coding modulation signal demodulation, namely, reduction of signal coding. The instruction decoder to the encoder signal decoding, Driven by the final circuit to drive the implementation of various instructions circuit to control the operation.1.3 infrared remote control transceiver product profiles 1.3.1 infrared remote control transceiver product structure and typeCurrently infrared transceiver in accordance with the mode of transmission rate and can be divided into four categories : Serial mode, the highest rate of 115.2 Kbps; medium-speed model : the highest rate of 0.567 Mbps and 1.152Mbps; High-speed mode : The maximum rate of 16 Mbps.Also according to the size chip power consumption can be divided into low-power consumption and standard two categories, low-power type normally used 3 V power supply, transmission distance closer to about 0 - 30cm, which is commonly used standard 5V power supply, transmission distance away at least 1mabove.1.3.2 infrared remote control transmitters of the status quo at home and abroadInfrared communication technology in the development stage and there are several infrared communication standards, between different standards for infrared equipment can not infrared communication. To have all the infrared equipment to interoperability in 1993 by more than 20 large manufacturers initiated the establishment of an Infrared Data Association (IRDA) unified the infrared communication standards , which is currently widely used in infrared data communication protocols and standards, also known as the IRDA standard.Since 1993 IRDA since the establishment of the Infrared Data Association members have developed to more than 150. IRDA standards of the industry has been widely recognized and supported. Has been developed with the infrared communications equipment have been as many as 100 species. IR module, installed capacity has reached 150 million sets. Although there is also a short distance wireless Bluetooth technology, But in infrared communication technology low cost and broad compatibility advantages, Infrared data communication in the future will still be a very long time inherent short-range wireless data communications fields play an important role.1.3.3 Infrared Transceiver product development trendIn various infrared transceiver products, although the transmission rate, transmission distance and other characteristics, But infrared transceiver products has been towards improving the transmission rate, increase the transmission distance and lower power consumption, expanding launch reception angle of development. In particular, as the technology development and maturity, the means of transmission is moving in the direction of point-to-multipoint. Therefore infrared remote control transceiver products have broader prospects for development.2 Infrared communication of knowledge2.1 infrared ray foundation knowledge2.1.1 infrared outlinedInfrared is actually a kind of electromagnetic wave. From the analysis of various natural component of the electromagnetic wave reflected spectrum is :-ray, x-ray, ultraviolet, visible, infrared, microwave and radio wave. From the viewpoint of form, and they did not seem to, but if the wavelength in descending order, and we will find him all the only visible light spectrum of the entire 0.38 µm - 0.76µm so long little area, and adjacent to the visible light and infrared (including the far infrared, mid-infrared and near infrared foreign) accounts for the spectrum of 0.76 µm - 1000µm of a major. Which micron wavelength range also includes UV, visible, near infrared, mid-infrared and far-infrared, microwave.From the above analysis shows that infrared is a very rich spectrum resources, it currently has in production, life, military, medical, and other aspects have been widely used, such as infrared heating, medical infrared, infrared communication, infrared camera, infrared remote control, and so on. Infrared remote control is the many applications of infrared part of the current household appliances widely used in TV remote control, VCR remote control, VCD remote control, high-fidelity audio remote control, are used infra-red remote control, It allows the control of these appliances have become very easy.2.1.2 infrared propertiesInfrared lies between visible light and microwave a wave, it is with certain clinical characteristics of the wave. In the near-infrared, visible light and its adjacent, it is visible in certain characteristics, such as straight-line transmission, reflection, refraction, scattering, diffraction, can be certainobjects and can be absorbed through the lens of their focusing. In the far-infrared region, owing to its neighboring microwave, it has some characteristics of microwave, If a strong penetrating power and can run through some opaque substances. Since in any object, natural profession, regardless of whether its own luminescence (referring to visible light), as long as the temperature is above absolute zero (-273 ° C), moment will be kept around to infrared radiation. Only higher temperature of objects strong infrared radiation, low-temperature objects infrared radiation weaker. Therefore infrared feature is the greatest common in nature, it is called thermal radiation called thermal radiation. Infrared cameras, infrared night market pyroelectric infrared detectors and some other missiles aiming at is the use of this characteristic of infrared work.Infrared and visible light compared to another characteristic of a variety of colors. As the longest wavelength of visible light is a wavelength of the shortest times (780 nm-380 nm), So is called an octave. And infrared wavelength is the longest shortest wavelength of a times, and the longest wavelength infrared is the shortest wavelength of 10 times, that is, 10 octave. Therefore, if visible light can be expressed as seven colors, infrared may performance 70 colors, showing the rich colors. Infrared smoke through the good performance, which is also one of its features.Because not visible to the infrared, it has little effect on the environment. By the wave infrared rays than the long wavelength radio waves, infrared remote control will not affect the nearby radio equipment. Another wavelength of less than 1.5µm near infrared light, transparent atmosphere in the visible light transmission characteristics much better than, because it close to the visible edge of the red light, linear transmission, reflection, refraction and absorption material and the physical characteristics very similar to visible light. Therefore, it can be used with similar visible focusing lens and other opticaldevices. Because infrared remote control is not as remote as the radio through the barrier to control the object's ability to control, so in the design of household appliances infra-red remote control, wireless remote control as unnecessary, each set (transmitters and receivers) have different frequency or remote coding (Otherwise, wall will control or interference with neighbors household appliances), all similar products in the infrared remote control, The same can control the frequency or coding, and no remote control signal "drop." This universal infrared remote control provides a great convenience. Infrared to visible light, is very subtle and confidentiality, therefore, the security, Alert and other security devices have been widely used. Infrared remote control is simple in structure and easy, low-cost, anti-interference capability, high reliability are a number of advantages, is a close-up remote control, especially in indoor remote control optimized manner.2.1.3 infrared diode characteristicsInfrared is not visible, people here are not aware of. Electronic technology is used infrared light emitting diode (also known as the IR emission diode) to generate infrared. Infrared remote control transceiver is using near-infrared transmission control instructions 0.76µm wavelength of ~ 1. 5µm. Near-infrared remote control as a light source, because there infrared light emitting diodes and infrared receiving device (photodiode. Transistor and PV) and the luminescence peak wavelength of light by the general 0.8µm ~ 0. 94µm. in the near-infrared band, both of the spectrum is the coincidence to a good match, access to higher transmission efficiency and higher reliability. Commonly used infrared diode, and its shape is similar LED light emitting diodes, Its basic circuit shown in figure 2 -2. The triode plans for the switch, when the base added a driving signal, Transistor saturated conduction infrared LED D is also Wizard Link, issued infrared (near infrared about 0.93 µm). D.The pressure drop of about 1.4 V and the current general for 10-20mA. To adapt to the working voltage of the D loop resistance often as a series of infrared diode current limit resistance.When the circuit diagram of the infrared emission control corresponding to the controlled device, the control of the distance and D is proportional to the transmitting power. In order to increase the distance of infrared control, infrared diode D should work on the pulse state that work is the lifeblood of current. Because pulse light (optical modulation) the effective transmission distance and pulse is proportional to the peak current, only maximize peak current Ip, will increase the infrared distance. Ip increase is a way to reduce the pulse duty cycle, that is compressed pulse width τsome TV infrared remote control, its infrared luminescence of the pulse duty cycle of about 1/4-1/3; Some electrical products infrared remote control, its duty cycle of 1 / 10. Decreasing pulse duty cycle also enable low-power infrared LED distance of the greatly increased. Common infrared light emitting diodes, power is divided into small power (1 mW - 10mW). Chinese power (20mW - 50mW) and power (50mW - 100mW more) three categories. Use different power infrared LED, the allocation should be driven by the corresponding power control. Figure 2 -2 by the reflected infrared light-emitting diodes to make produce optical modulation, Drivers only need to add the control of a certain frequency pulse voltage.Infrared transmitter and receiver in the way the two kinds of straight, and the second is reflective. Luminescence pointed straight pipe and tube receiver placed in a relatively controlled and fired on the two ends, a certain distance away from the middle; Reflective means luminescent tube and pipe parallel with the receiving peacetime, without always receiving tube light, luminescence only in possession of the infrared light reflected fromencountered, the receiving tube received from the reflected infrared before work.2.2 infrared communication basic tenets2.2.1 infrared communication PrincipleCommunication is the use of infrared wavelength of 900 nm-infrared waves from 1000 to serve as an information carrier, through infrared technology between the two close communication and confidentiality of information transmitted. Infrared communication system structure include : part launcher, channel, the receiver part.Launcher source letter issued after the binary signal from the high-frequency modulated infrared LED sent, receiving device regard the reception of high-frequency signals from the infrared receiver tube after receiving further demodulation photoelectric conversion of the original information of a mass communication lose way. Afterwards the former Information received after receiving part of the drive circuit connected to the expected completion of the various functions. To which the modulation coding style pulse width modulation (by changing the pulse width modulated signal PWM) and pulse modulation time (through change the pulse train interval time between the modulation signal PPM) two.2.2.2 infrared communication system elements(1) Launches : Currently there is a infrared wireless digital communications system sources of information including voice, data, images. Its methods of work for the launch of the receiver can be divided into different layout LOS way (Light-of-Sight , intracardiac way), diffuse (diffuse) mode. LOS way directional, it has good channel characteristics such advantages, but the existence of a "shadow" effect. difficult to achieve roaming function. Roaming means the main features of non-directional, and easy to implementroaming function, but its channel quality is better sometimes LOS way. Transmission of signals required for a few of (the sampling was quantified), the general need for baseband modulation, transmission, modulation, sometimes signal source coding, the above-driven signals from photoelectric converter complete optical signal transmission. Infrared wireless digital communications system and its scope of work-for-fired power distribution, the quality of the communication. While using various methods to improve optical transmitter power, the other using spatial diversity, holographic films and so on so diffuse light for the launch of space optical power evenly distributed.(2) Channel : infrared wireless digital communication channel refers to the transmitters and receivers in the space between. Due to natural light and artificial light sources such as light signals in the context of intervention, and the source - Electrical Equipment, The optical noise and disturbances, infrared wireless digital communications in some occasions, poor quality, At this point needed to channel coding. Infrared wireless communication system, the optical signal reflection, light scattering and background noise and interference effects, Infrared wireless digital channel presence multi-path interference and noise, This is to improve the quality and access for high-speed applications should be addressed. Infrared wireless digital communication channel often used by the major optical components, optical filter, condenser, their role is : plastic, filter, depending on the field transformation, the band division, the lens can be used as launch-ray focusing, the use of optical filters filter out stray light, the use of optical lenses to expand the field of view receiver, able to make use of optical components for the link frequency division multiplexing, etc.. Infrared wireless communication channel optical noise : the natural noise (sunlight) and anthropogenic interference (fluorescent lighting). can be modulated by the transmission technology such as filters and adding to be addressed.(3) receivers : Channel optical signal from the optical receiver partially photoelectric conversion, In order to remove noise and intersymbol interference and other functions. Infrared wireless digital communications system receiver include optical receiver parts and follow-up sampling, filtering, judgment, quantity, balanced and decoding part. Infrared wireless optical receiver often used amplifier, and called for large-bandwidth, high gain, low noise and low noise, frequency response and channel impulse response matched. To be suppressed by low-frequency noise and human disturbance needs a band-pass filter. To obtain large optical receiver scope and instantaneous field of view, often using spherical optical lens.2.2.3 infrared communications featureWireless communications are a lot of ways, some using infrared communication with the following characteristics :• The high frequency, wave length, and fired the energy concentrated space propagation attenuation coefficient can ensure the effective signal transmission;• infrared is the invisible light, strong confidentiality and use it as an information carrier. device when there is no visual pollution, it does no harm to the human body;• dissemination without limitation, and there is no question of frequency interference with radio-wave pattern, not on the spectrum resources to the relevant authorities for the application and registration, easy to implement;• has a good point, when the transmission equipment and infrared receiver ports line up straight, deviation of not more than about 15 degrees when infrared devices running the best effect;• through infrared or not bypassed and objects, data transmission, optical path can not be blocked;• currently produce and receive infrared signals in the technology is relatively mature, components small size, low cost production of simple, easy to produce and modulation advantages.2.3 infrared communication code based on the knowledgeUsually, infrared remote control transmitters will signal (pulse binary code) modulation at 38 KHz carrier, After buffer amplified sent to the infrared light-emitting diodes, infrared signals into firing away. Pulse binary code in a variety of formats. One of the most commonly used code is PWM (pulse width modulation code) and the PPM code (Pulse Code Modulation). The former said in a pulse width, pulse indicated 0. The latter pulse width, but the width of code-not the same, the codes represent a bit - and the digits represent narrow 0.Remote coding pulse signal (PPM code as an example) are usually guided by the code, the system code, the anti-code system, a feature code, functional anti-code signal components. Guide the code name for the initial code, by the width of 9 ms and the margin width of 4.5 ms to the low-level components (different remote control systems in the low-level high width of a certain distinction), remote coding used to mark the beginning of pulsed signals. System identification code is also called code, which used to indicate the type of remote control system, in order to distinguish other remote-control system, prevent the remote control system malfunction. Functional code is also called scripts, which represents the corresponding control functions, Receiver of the micro-controller functions under the numerical code to complete the various functions operating. Anti-code system and function codes are anti-system code and the functional code against code Anti-code can be joined to the receiver synchronization transmission process leads to errors. In order to improve performance and reduce interference power consumption, The remote control will be coded pulse frequency of 38 KHz (for the cycle of 26.3 ms) of the carrier signal pulse reshuffle system (PAM), and then sentto the buffer amplified infrared LED, the remote control signal transmitter away.Address code and data codes are composed of different pulse width expressed that the two narrow pulse "0"; 2 pulse width "1"; a narrow pulse width and pulse expressed an "F" is the code addresses "vacant."Is the first part of a group a group of code, each code synchronization between separated. The plan is to enlarge the second half of a group code : a code from 12 AD (the address code plus data code For example, eight address code plus four data code), each with two AD-Pulse's : Pulse said the two "0"; 2 pulse width "1"; a narrow pulse width and pulse expressed an "F" is the code addresses "vacant."Realize fired at each fired at least four groups code, PT2272 only twice in a row to detect the same address code plus data code data will be the code "1" is driven The data should be output to drive margin and VT terminal for synchronous serial.红外遥控系统摘 要红外数据通信技术是目前在世界范围内被广泛使用的一种无线连接技术，被众多的硬件和软件平台所支持。
关于电子信息工程的英语作文
关于电子信息工程的英语作文English: Electronic Information Engineering is a branch of engineering that focuses on the study and application of electronic devices and communication systems in various fields. This field combines principles from electrical engineering and computer science to design, build, and maintain electronic systems that process, transmit, and store information. Electronic Information Engineering plays a crucial role in shaping the technologies we use in our daily lives, such as smartphones, computers, telecommunication networks, and more. Professionals in this field work on developing advanced technologies like artificial intelligence, Internet of Things, and 5G networks to improve communication, automation, and data processing efficiency. With the rapid development of technology, Electronic Information Engineering will continue to evolve and pave the way for innovative solutions to various societal challenges.中文翻译: 电子信息工程是一门工程学的分支，专注于研究和应用电子设备和通信系统在各个领域。
电子信息工程毕业设计外文翻译
xx大学毕业设计外文翻译系别职业技术教育学院专业电子信息工程班级电子Z091 学号 x姓名 x指导教师 x2013年5月16日MM420 inverter energy-saving measures in the water supply system-Nanjing Hangda Yihang Technology Co., Ltd.Because the frequency conversion velocity modulation does not need to construct the tradition for the aqueous system for the aqueous system top digit water tank, the water tank, avoided two times polluting and reducing the construction investment, moreover designed reasonably can achieve the good energy conservation effect.In gives in the aqueous system, the constant speed pump only then in its highly effective section movement can guarantee the system normal work also does not have the energy dissipation.In the design, (this time current capacity is generally biggest by the pipe network most unfavorable situation, must lift is also biggest) takes the choice water pump unit the main basis, but when the pipe network current capacity reduces, the energy waste is inevitable, when also possibly creates the low current capacity in pipeline overpressure question.The water pump basis system current capacity real-time change realization stepless speed regulation movement, is solves above problem well, achieves one of energy conservation goal ways.The water pump velocity modulation may through the very many way realization, in which frequency conversion velocity modulation be the present ideal one kind.The frequency conversion velocity modulation is through will give on the aqueous system pipe network the pressure transmitter to carry on the sampling to the pipe network hydraulic pressure, transforms the pressure signal into the electrical signal, and delivers to the PID regulator and the user establishment value of pressure it carries on the comparison and the operation, finally will transform for the frequency control signal delivers to the frequency changer.The frequency changer basis transmits frequency control signal adjustment water pump electrical machinery supply frequency, thus realizes adjusts the water pump the rotational speed.May divide into two kinds according to the customer in actual use request frequency conversion velocity modulation for the aqueous system: The live pressure variable gives the aqueous system for the aqueous system and the constant pressure variable.The live pressure variable establishes for the aqueous system pressure transmitter in the service pipe net terminal, the PID regulator setting value the service flood peakvalue which needs for the pipe network terminal user.The system causes the pipe network terminal hydraulic pressure maintenance through the automatic control to be constant, causes the pipeline characteristic curve and system static lifting is invariable, but the water pump water outlet pressure changes along with the volume of diversion change according to the pipeline characteristic curve, therefore theoretically realized “the system to need how many, the unit provided how many”, could not because the volume of diversion reduced has unnecessary static lifting, the energy conservation effect was satisfied.But this is only one kind of ideal situation, also in the system only has the frequency conversion pump alone to work.Because the frequency conversion equipment quite is expensive, large-scale often uses the frequency conversion pump and the constant speed pump parallel operation way water supply for the aqueous system.Presently establishes a frequency conversion pump and a power frequency pump and the combined transport behavior example by the system in.When the pipe network current capacity reduces, needs to lift reduces correspondingly, the frequency conversion pump may through the deceleration movement realization.But also must reduce correspondingly for guarantee parallel unit normal work power frequency pump lifting, this only can through increase the current capacity realization, thus creates the water volume the dropout, also possibly causes the power frequency pump to leave the highly effective section work, namely has not achieved the true energy conservation the goal.Meets has above situation, may take following measure to improve its energy conservation effect:①Gives the aqueous system regarding the small scale, may only suppose a frequency conversion pump, and causes the pump the highly effective area (its highly effective scope to move the time scope compared to power frequency pump to want as far as possible many including to appear the probability big operating point in a big way).②Uses the multi-Taiwan pump velocity modulation movement, certainly, quite is expensive as a result of the frequency conversion speeder price, should overall evaluation its economic agent decide.③When choice power frequency pump, should cause the system when the most disadvantageous spot work, the power frequency pump operating point approaches left side of as far as possible its highly effective area; If the most unfavorable situation appears the probability to be small, may enable it to deviate slightly the highlyeffective area, falls in the highly effective area left flank.Thus, when system lifting reduces, the power frequency pump still may in the highly effective area work.The constant pressure variable is located in the water pump unit water outlet for the aqueous system the pressure transmitter, is for the purpose of causing the water pump water outlet pressure maintenance to be constant, general hypothesis for most disadvantageous operating mode when the water pump water outlet needs the value of pressure.Still by a frequency conversion pump and a power frequency pump and combined transport behavior example.When the pipe network current capacity reduces, the frequency conversion pump through the deceleration movement, maintenance lifting invariable reduces the water discharge.Because the outlet pressure is invariable, the power frequency pumps out the water volume not to be able to change (i.e. movement operating mode invariably), still in highly effective area work, thus achieves the energy conservation goal.Needs to point out, the system needs when the current capacity changes small, the water pump water outlet pressure (still for the most unfavorable situation in system needs pressure) to be bigger than the pressure which the pipeline this time needs, thus still could cause static lifting to a certain extent the waste.Following two measures may improve its energy conservation effect:①Enlarges the pipe network suitably the caliber, causes the pipeline characteristic curve to hasten gently, but this can increase the pipe network the disposable investment, needs and the energy conservation effect makes the comprehensive economical comparison.②When choice power frequency pump causes each pump the operating point to fall as far as possible on the highly effective area.For aqueous system when water used trough (for example at night), in the system the water consumption is very small, even achieved the zero current capacity, is called “the micro current capacity”.In this case, if depends upon at the highly effective area great current capacity scope movement water pump maintains the system pressure, not only buckle water pump life, moreover the efficiency is low, cannot achieve the energy conservation the goal.Theoretically, the frequency conversion pump current capacity may approach in the highly effective scope in the zero, but in fact the water pump rotational speed not impossible unlimited to reduce, only depends on the frequency conversion pump to be competent the micro current capacity operating mode with difficulty toward the dealings.The actual project uses generally when the system additionally builds the small current capacity power frequency auxiliary pump,small current capacity facilities and so on frequency conversion auxiliary pump, barometric pressure pot maintain the micro current capacity the system pressure.To the different system micro current capacity question should the special details concrete analysis, and carries on the overall evaluation to the disposable investment and the long-term operating cost to be able to make the reasonable solution.In the frequency conversion velocity modulation for in the aqueous system design process, should choose the pump reasonably according to the service pipe net characteristic, achieved in satisfies the operation requirements under the premise, both saves the goal which the investment and conserves energy.MM420变频器在给水系统的几点节能措施-南京航大意航科技股份有限公司由于变频调速给水系统不需要建造传统给水系统的高位水箱、水塔，避免了二次污染并减少了土建投资，而且设计得合理能达到较好的节能效果。
电子信息工程 微处理器 外文翻译 外文文献 英文文献
外文资料所译外文资料：1.作者G..Bouwhuis, J.Braat, A.Huijser2.书名：Principles of Optical Disk Systems3.出版时间：1991年9月4.所译章节：Session 2/Chapter9, Session 2/Chapter 11原文：MicroprocessorOne of the key inventions in the history of electronics, and in fact one of the most important inventions ever period, was the transistor. As time progressed after the invention of LSI integrated circuits, the technology improved and chips became smaller, faster and cheaper. The functions performed by a processor were implemented using several different logic chips. Intel was the first company to incorporate all of these logic components into a single chip, this was the first microprocessor. A microprocessor is a complete computation engine that is fabricated on a single chip. A microprocessor executes a collection of machine instructions that tell the processor what to do. Based on the instructions, a microprocessor does three basic things: ing the ALU (Arithmetic/Logic Unit), a microprocessor can perform mathematical operations like addition, subtraction, multiplication and division; 2.A microprocessor can move data from one memory location to another; 3.A microprocessor can make decisions and jump to a new set of instructions based on those decisions.There may be very sophisticated things that a microprocessor does, but those are its three basic activities. Microprocessor has an address bus that sends an address to memory, a data bus that can send data to memory or receive data from memory, an RD(read) and WR(write) line that lets a clock pulse sequence the processor and a reset line that resets the program counter to zero(or whatever) and restarts execution. And let’s assume that both the address and data buses are 8 bits wide here.Here are the components of this simple microprocessor:1. Registers A, B and C are simply latches made out of flip-flops.2. The address latch is just like registers A, B and C.3. The program counter is a latch with the extra ability to increment by 1 when told to do so, and alsoto reset to zero when told to do so.4. The ALU could be as simple as an 8-bit adder, or it might be able to add, subtract, multiply anddivide 8-bit values. Let’s assume the latter here.5. The test register is a special latch that can hold values from comparisons performed in the ALU. AnALU can normally compare two numbers send determine if they are equal, if one is greater than the other, etc. The test register can also normally hold a carry bit from the last stage of the adder. It stores these values in flip-flops and then the instruction decoder can use the values to make decisions.6. There are six boxes marked “3-State”.These are tri-state buffers. A tri-state buffer can pass a 1, a 0or it can essentially disconnect its output. A tri-state buffer allows multiple outputs to connect to a wire, but only one of then to actually drive a 1or a 0 onto the line.7. The instruction register and instruction decoder are responsible for controlling all of the othercomponents.Although they are not shown in this diagram, there would be control lines from the instruction decoder that would:1. Tell the A register to latch the value currently on the data bus2. Tell the B register to latch the value currently on the data bus3. Tell the C register to latch the value currently on the data bus4. Tell the program counter register to latch the value currently on the data bus5. Tell the address register to latch the value currently on the data bus6. Tell the instruction register to latch the value currently on the data bus7. Tell the program counter to increment8. Tell the program counter to reset to zero9. Activate any of the six tri-state buffers (six separate lines)10. Tell the ALU what operation to perform11. Tell the test register to latch the ALU’s test bits12. Activate the RD line13. Activate the WR lineComing into the instruction decoder are the bits from the best register and clock line, as well as the bits from the instruction register.RAM and ROM The address and data buses, as well as the RD and WR lines connect either to RAM or ROM—generally both. In our sample microprocessor, we have an address bus 8 bits wide and a data bus 8 bits wide. That means that the microprocessor an address (2n) 256 bytes of the memory and it can read or write 8 bits of the memory at a time. Let’s assume that this simple microprocessor has 128 bytes of ROM starting at address 0 and 128 bytes of RAM starting at address 128.ROM stands for read-only memory. A ROM chip is programmed with a permanent collection ofpre-set bytes. The address bus tells the ROM chip which byte to get and place on the data bus. When the RD line changes state, the ROM chip presents the selected byte onto the data bus.RAM stands for random-access memory. RAM contains bytes of information, and the microprocessor can read or write to those bytes depending on whether the RD or WR line is signaled. One problem with today’s RAM chips is that they forget everything once the power goes off. That is why the computer needs ROM.By the way, nearly all computers contain some amount of ROM (it is possible to create a simple computer that contains no RAM—many microcontrollers do this by placing a handful of RAM bytes on the processor chip itself—but generally impossible to create one that contains no ROM).On a PC, the ROM is called the BIOS (Basic Input/Output System). When the microprocessor starts, it begins executing instructions it finds in the BIOS. The BIOS instructions do things like test the hardware in the machine, and then it goes to the hard disk to fetch the boot sector. This boot sector is another small program, and the BIOS store it in RAM after reading it off the disk. The microprocessor then begins executing the boot sector’s instructions from RAM. The boot sector program will tell the microprocessor to fetch something else from the hard disk into RAM, which the microprocessor then executes, and so on. This is how the microprocessor loads and executes entire operating system.Microprocessor Instructions Even the incredibly simple microprocessor shown here will have a fairly large set of instructions that it can perform. The collection of instructions is implemented as bit patterns, each one of which has a different meaning when loaded into the instruction register. Humans are not particularly good at remembering bit patterns, so a set of short words are defined to represent the different bit patterns. This collection of words is called the assembly languages of the processor. An assembler can translate the words into their bit patterns very easily, and then the output of assembler is placed in memory for the microprocessor to execute. If you use C language programming, a C compiler will translate the C code into assembly language.So now the question is, “How do all of these instructions look in ROM?” Each of these assembly language instructions must be represented by a binary number. These numbers all know as recodes. The instruction decoder needs to turn each of recodes into a set of signals that drive the different components inside the microprocessor. Let’s take the ADD instruction as an example and look at what it needs to do.During the first clock cycle, we need to actually load the instruction. Therefore the instruction decoder needs to: activate the tri-state buffer for the program counter; activate the RD line; activate the data-in tri-state buffer; latch the instruction into the instruction register.During the second clock cycle, the ADD instruction is decoded. It needs to do very little: set the operation of ALU to addition; latch the output of the ALU into the C register.During the third clock cycle, the program counter is incremented (in theory this could be overlapped into the second clock cycle).Every instruction can be broken down as a set of sequenced operations like these that manipulate thecomponents of microprocessor in the proper order. Some instructions, like this ADD instruction, might take two or three clock cycles. Others might take five or six clock cycles.Microprocessor Performance The number of transistors available has a huge effect on the performance of a processor. As seen earlier, a typical instruction in a processor like an 8088 took 15 clock cycles to execute. Because of the design of the multiplier, it took approximately 80 cycles just to do one 16-bit multiplication on the 8088. With more transistors, much more powerful multipliers capable of single-cycle speeds become possible.More transistors also allow for a technology called pipelining. In a pipelined architecture, instruction execution overlaps. So even though it might take five clock cycles to execute each instruction, there can be five instructions in various stages of execution simultaneously. That way it looks like one instruction completes every clock cycle.Many modern processors have multiple instruction decoders, each with own pipeline. This allows for multiple instruction streams, which means that more than one instruction can complete during each clock cycle. This technique can be quite complex to implement, so it can be lots of transistors.The trend in processor design has been toward full 32-bit ALU with fast floating point processors built in and pipelined execution with multiple instruction streams. There has also been a tendency toward special instructions that make certain operations particularly efficient. There has also been the addition of hardware virtual memory support and L1 caching on the processor chip. All of these trends push up the transistor count, leading to the multi-million transistor powerhouses available today. These processors can execute about one billion instructions per second!The Operational Amplifier will continue to be a vital component of analog design because it is a fundamental component. Each generation of electronic equipment integrates more functions on silicon and takes more of the analog circuitry inside the IC. As digital applications increase, analog applications also increase because the predominant supply of data and interface applications are in the real world, and the real world is an analog world.The LM386 is a power amplifier designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200.The inputs are ground referenced while the output automatically biases to one-half the supply voltage. The quiescent power drain is only 24 mill watts when operating from a 6 volt supply, making the LM386 ideal for battery operation.A Crystal is a basic piezoelectric quartz crystal. On its own, it cannot generate electrical clocks. It has to be connected to a clock oscillator to get a clock waveform. There are two kinds of crystals: Series Resonant, which can be modeled as a high Q series LC circuit, and Parallel Resonant, which can be modeled as a high Q parallel LC circuit. A Crystal Oscillator is an oscillator with the crystal as the feedback element. There are other kinds of oscillators with active or passive feedback components, but the crystal oscillator provides the most accurate and stable output frequency. Crystal oscillators are the preferred clocksource in most high-speed digital systems requiring clocks. A chip is a small piece of conducting material on which an integrated circuit is embedded. A microprocessor is a silicon chip that contains a CPU. In operation, a computer is both hardware and software. One is useless without another. The hardware design specifies the commands it can follow, and the instructions tell it what to do. With the infiltration in the social field of the computer in recent years, the application of the one-chip computer is moving towards deepening constantly, drive tradition is it measure crescent benefit to upgrade day to control at the same time. In measuring in real time and automatically controlled one-chip computer application system, the one-chip computer often uses as a key part, only one-chip computer respect knowledge is not enough, should also follow the structure of the concrete hardware , and direct against and use the software of target's characteristic to combine concretely, in order to do perfectly.译文：微处理器晶体管是电子学发展史上的关键发明之一，它实际上也是人类历史上最重要的发明之一。
电子信息工程外文翻译外文文献英文文献文献翻译
Technology and Application of Fieldbus Control System -------- IntelligentEquipment & Measurement And Control System Based on DeviceNetPromoted by the new technological revolution that automation control technology is tending digitization and internet in the field of automation industry, Shanghai Aton Electric Co., Ltd. developed Intelligent Equipment & Measurement And Control System Based on DeviceNet as a high and new technology industrialization model project. It was a state hi-tech development project of 2000 and was approved by the State Committee of Technology. Shanghai Aton Electric Co., Ltd. constructed production line of intelligent controller of pump and valve, relying on Shanghai Electric (Group) Corporation; constructed measurement and control system FCS R&D center of intelligent controller of pump and valve and built up mass production R&D basis, cooperating with Shanghai Jiaotong University and Shanghai University; constructed FCS remote diagnosis and service center of intelligent controller of pump and valve; constructed FCS training center of intelligent controller of pump and valve; founded mass production R&D basis along with the Rockwell Laboratory of Shanghai Jiaotong University and CIMS Center.1 Summary(1)Fieldbus control system is a system applied to field of production and microcomputerized measurement control equipment to realize both-way multinode serial communications. It is also called low-level control network for open, digital and multiplespot communications.Application: Flow Control System of Manufacturing; Process Control System; Traffic Control & Management; Building Automation. Features: Fieldbus control system is low-level low-bandwidth digital communication and control network in industrial system as well as open system connecting microcomputerized appearance. Intelligent instrument and controller are equal to microcomputer. They make up network with Fieldbus control system as the links to complete digital communication and other tasks.(2)Difference between FCS and DCS,FCS is updated control system after DCS integrated with digital control system and distributing control system. It solves the problem that in traditional DCS, devices made by different manufacturers cannot be connected. They can't realize exchange and operation to organize an network system with wider range of information sharing. It conquers the defect that special closed system for network should be used for communication in DCS to realize various functions of integrated automation. It turns the distributing structure combining concentration with deconcentration in DCS into new-type full distributing structure. Itreleases the control function to the field thoroughly and makes it possible to realize basic control function by means of fieldbus equipment itself. FCS breaks the traditional structure form of control system. The traditional analog control system adopts one-to-one equipment tie-wire and puts up connections respectively according to control loop. FCS adopts intelligent field equipment to place the control module, all input/output modules that used to be in the control chamber of DCS into field equipment. Since field equipment has ability to communicate, the field measuring and transferring instruments can transfer signals to actuating mechanism such as valve directly. Its control function can be fulfilled directly on the spot independent of the computer or control meter in the control chamber, which realizes thorough decentralized control.FCS adopts digital signals to replace analog signals so that multiple signals (including multiple operating parameter values, device status and failure information) can be transferred on a pair of cables. Meanwhile, it can give power supply to several devices. No switched block for analog/digital or digital/analog is needed besides fieldbus.(3) C haracteristics of FCS• Open System;• Interoperability;• replace ability of devices made by different manufacturers.• Intelligentize and Autonomy;• Field equipment completing basic functions of automatic control.• Decentralized System Structure;• Field Adaptability;• Relatively Strong Interference Killing Feature and Safety• Intelligentized local equipment can save investment and quantity of hardware• Saving installation expenses and cables• Saving daily maintenance expenses• Enhancing accuracy and reliability of system• Enhancing initiativeness of system integration for users(4) Development Background and Trend of Fieldbus Control System, With the rapid development of computer and computer network, FCS has been rapidly developed as the interlinked communication network between the field intelligentdevices in the field of process automation, building and traffic etc. Because FCS meets the needs that industrial control system is developing in the way of decentralization, network and intellectualized, it has become the focus of global industrial automation and been universally concerned by the whole world. FCS has causedgreat revolutions on the aspects of system structure and function system for the current production of automation instrument, distributing control system and programmable controller. It is predicted that FCS will be the general trends in a very long time in the future fore sure.2 APPLICATION OF RELAYThe product reliability generally refers to the operating reliability. It is defined as: the ability of accomplishing the specified function under prescribed conditions and in prescribed time. It consists of intrinsic reliability and application reliability. The intrinsic reliability is determined by product designing and manufacturing technique, and the application reliability is concerned with the correct application of users and the services provided by the manufacturer before and after selling. When using relay, the user should pay attention to the following items.2.1 Coil applied voltageIt is best to choose the coil applicative voltage according to the rated voltage in design, or choose the voltage according to the temperature rising curve. Using any coil voltage that is less than the rated voltage will affect the operation of the relay. The coil operating voltage refers to the voltage that is applied between the coil terminals. The voltage value between the two terminals must be guaranteed, especially when using enlargement circuit to energize the coil. Whereas, it will also affect the relay characteristics if the applied voltage exceeds the highest rated voltage. Exorbitant voltage will bring exorbitant coil temperaturerising, especially in high temperature ambient. Exorbitant temperature rising will damage the insulating material and affect the working safety of relay. For magnetic latching relay, energizing (or return) pulse width should not less than 3 times of the operating (or return) time, otherwise, the relay would be left on the middle-position state. When using solid-state components to energize the coil, the components dielectric strength must be above 80V, and the leakage of current must be as little as possible to ensure the relay to release.Energizing power source: Under 110% of the rated current, the adjusting ratio of the power source is less than 10% (or the output impedance is less than 5% of the coil impedance), the wave voltage of the DC power source is less than 5%. The AC wave is sine wave; the waviness coefficient is between 0.95~1.25; wave distortion is within ±10%; the frequency change is within ±1Hz or ±1% of the specified frequency (choosing the bigger value). The output power should not less than coil power consumption.2.2 Transient suppressionAt the moment when the coil power is stopped, peak-inverse voltage that is more than 30 times ofthe coil rated voltage is produced on the coil, which is harmful to the electronic circuit. Generally, the peak-inverse voltage is suppressedby transient suppression (cutting-peak) diode or resistance to limit the peak-inverse voltage within 50V. But the diode in parallel connection will delay3~5 times of the release time. If the request of the release time is high, a suitable resistance in series can be putted with and at one end of the diode.The power supply to relays in parallel connection and series connection, When several relays in parallel connection are supplied, the relay that the peak-inverse voltage is higher will release power to the relays that the peak-inverse voltage is lower. The release time of the relay will delay. So the relays in parallel connection should be controlled separately to eliminate mutual influence.The relays with different coil resistance and power can'bt e used in series, otherwise, the relay that the coil current is higher in the series circuit can'otperate reliably. Only the relays of the same specification can be used in series, but the peak-inverse voltage will be increased and the peak-inverse voltage should be suppressed. Resistance in series can be used to bear the part voltage that exceeds the rated voltage of the coil according to the ratio of the divided voltage.2.2.1 Contact loadThe load applied to the contacts should be accordant to the rated load and characteristics of the contacts. A load that is not applied according to the rated value range will cause problem. The relay that is only suitable for DC load can used in ' t be AC occasions. The relay that can switch 10A load can ' t always reliably operate in low level load (less tha n 10m AX6A) or in dry circuit occasi ons. The relay that can switch single-phase AC power source isn 'atlways suitable to switch two single-phase AC loads that aren 't synchronous; the relay that is onlyiesdpteocisfwitch the load of AC 50Hz(or 60Hz)can't be used to switch AC load of 400Hz.2.2.2 Parallel and series connection of contactsThe contacts used in parallel connection can ' t increase the load current, becausethe operating times of several sets of contacts are absolutely different; that is to say, there is still only a set of contacts switching the increased load. This would damage or weld the contacts and make the contacts can ' t close or open. The parallel connectionof the contacts can decreasehte misplay of “ break ” . But the parallel connection of the contacts would increase the misplay of “ freezing ”. Because the misplay of “bre the main pattern of invalidation of contacts, the parallel connection can increase the reliability and can be used on the pivotal part of equipments. But the applied voltage should not exceed the highest operating voltage of the coil and should not less than 90% of the rated voltage, otherwise, the coil life and the applicative reliability would be damaged. The series connection of the contacts can increasethe load voltage. The amount of the contact sets is equal to the times that the load voltage can be increased.The series connection of contacts can decrease the misplay of “ freezing ”, but it w increase the misplay of “ break ”An. yway, when using redundant technology to increase the operating reliability of contacts, the characteristics and size and the failure mode of load must be considered.2.2.3 Switching speedThe switching speed should not exceed the reciprocal of 10 times of the sum of operating and release time (times/s), otherwise, the contacts can ' t switch on stead Magnetic latching should be used under the pulse width specified in the technique criterion, or the coil may be damaged.3 RVT DISTRIBUTING ELECTRICITY INTEGRATE TEST APPARATUSBasic functionMeasure asupervision:Three mutually electric voltage/electric current/ power factor with a great achievement/ power without a great achievement/electricity with a greatachiverment/electricity/homophonic-wave electric voltage/ homophonic-wave electric/ current Day electric voltage/ electric current biggest and minimum value/fire for the failure Electric voltage over top, the limit/ lack mutually of time homophonic-wave analyzes is up to 13 times.The data is stored for 2 months. The data communicateRS232/485 communicating connect，The way in communicating can adopt the spot communicating or the long range communicating. ，Possible to settle invoke orthe solid hour invokes, responding to the modification and long ranges control of the parameter. Without power compensationTaking physics measuresas the power factor without a great achievement,the power factor with a great achievement and the dull place without power compensation;Y+ the combination method of the △，Y+ the △ connects the line method，Y+ △ , Y, the △ connects the line method. Data managementAccording to WINDOW98 operation terrace, data in communication automatically reports born statement, curve and pillar form diagrams. Circulation of the protectionWhen the charged barbed wire net of mutually electric voltage over press, owe to press, and a super limit hour fast cut off in expiation of capacitor，When the charged barbed wire net lacks mutually or super limit in the preface of zero hour fast cut off in expiation of capacitor. screen manifestationChinese operation interface ，Adopt 128*64 the back light liquid crystal display.The solid hour shows the charged barbed wire net relevant parameter.view manifestation to place the parameter.现场总线控制系统的技术和应用随着新的科学技术革命的出现，在自动化工业领域中，自动控制技术的发展趋向于数字化和网络互联化。
{信息技术}电子信息工程测控技术与仪器外文翻译外文文献英文文献
（信息技术）电子信息工程测控技术与仪器外文翻译外文文献英文文献外文出处：Springer-Link电子期刊附件1：外文资料翻译译文SJA1000独立的CAN控制器应用指南1介绍SJA1000是壹个独立的CAN控制器，它于汽车和普通的工业应用上有先进的特征。
由于它和PCA82C200于硬件和软件均兼容，因此它将会替代PCA82C200。
SJA1000有壹系列先进的功能适合于多种应用，特别于系统优化、诊断和维护方面非常重要。
本文是要指导用户设计基于SJA1000的完整的CAN节点。
同时本文仍提供典型的应用电路图和编程的流程图。
2概述SJA1000独立的CAN控制器有2个不同的操作模式：BasicCAN模式(和PCA82C200）兼容PeliCAN模式BasicCAN模式是上电后默认的操作模式。
因此，用PCA82C200开发的已有硬件和软件能够直接于SJA1000上使用，而不用作任何修改。
PeliCAN模式是新的操作模式，它能够处理所有CAN2.0B规范的帧类型。
而且它仍提供壹些增强功能使SJA1000能应用于更宽的领域。
2.1CAN节点结构通常，每个CAN模块能够被分成不同的功能块。
SJA1000使用[3][4][5]最优化的CAN收发器连接到CAN。
收发器控制从CAN控制器到总线物理层或相反的逻辑电平信号。
上面壹层是壹个CAN控制器，它执行于CAN规范[8]里规定的完整的CAN协议。
它通常用于报文缓冲和验收滤波，而所有这些CAN功能，均由壹个模块控制器控制它负责执行应用的功能。
例如，控制执行器、读传感器和处理人机接口（MMI）。
如图1所示，SJA1000独立的CAN控制器通常位于微型控制器和收发器之间，大多数情况下这个控制器是壹个集成电路。
图1CAN模块装置2.2结构图下图是SJA1000的结构图图2SJA1000的结构图根据CAN规范，CAN核心模块控制CAN帧的发送和接收。
接口管理逻辑负责连接外部主控制器，该控制器能够是微型控制器或任何其他器件。
电子信息工程专业毕设 文献翻译 附英文原文
5.3. 时钟独立的显性误差
对于每一个特定的GPS时钟，在每个适用的时间从KF1相位偏差估计值减去 UECC估计值， 去估计其OEIC的相位。 在测量加工， OEIC包含在几部分纳秒内(见 图4)。图4展示了的两种情况下地面工作站时钟S1的OEIC。在蓝线的可见区间和 KF1测距处理显然有别于没有测量的传播间隔。在测量处理期间，KF1估计误差 的观察目标部分包含在几部分纳秒内。OEIC的协方差顺序计算需要每个时间点 的 KF1相位偏差估计误差和UECC估计误差的互协方差矩阵值。 我尚未能计算这
X K 1|K 1 X K 1|K K K 1[ y K 1 y( X K 1|K )]
Hale Waihona Puke （5）5. 难以观察的 GPS 时钟系统
GPS时间是由作战空军（USAF）卡尔曼滤波器处理 GPS伪距测量产生的。 GPS时间是多个GPS时钟的平均相位， 可是， 通过 GPS伪距测量， 每个运行的GPS 时钟的时钟相位是难以观察的，演示如下。GPS导航星的轨道参数是从GPS伪距 观测可观察到的。从GPS伪距测量可以得到USAF（美国空军）卡尔曼滤波器估 计轨道参数和时钟同步参数， 因此以这种方式将状态估计值分为隐式的时钟参数 子集和显式的轨道参数子集。通过应用谢尔曼有关MU函数的定理，演示了这种 分区方式。
4.3.2. 非线性函数 MU
计算 n ×1 矩阵滤波器增益 K K 1 ：
T T 1 K K 1 PK 1|K H K 1 [ H K 1 PK 1| K H K 1 R K 1 ]
（4）
滤波器测量更新 n×1 状态估计矩阵 X K 1|K 1 ，观测 yK+1 得
态估计误差协方差方阵（正特征值）
电子通信专业 外文翻译 外文文献 英文文献 电信现代运营
毕业设计（外文翻译材料）Telecommunication Modern Operation TelephoneIn an analogue telephone network, the caller is connected to the person he wants to talk to by switches at various telephone exchanges. The switches form an electrical connection between the two users and the setting of these switches is determined electronically when the caller dials the number. Once the connection is made, the caller's voice is transformed to an electrical signal using a small microphone in the caller's handset. This electrical signal is then sent through the network to the user at the other end where it transformed back into sound by a small speaker in that person's handset. There is a separate electrical connection that works in reverse, allowing the users to converse.The fixed-line telephones in most residential homes are analogue — that is, the speaker's voice directly determines the signal's voltage. Although short-distance calls may be handled from end-to-end as analogue signals, increasingly telephone service providers are transparently converting the signals to digital for transmission before converting them back to analogue for reception. The advantage of this is that digitized voice data can travel side-by-side with data from the Internet and can be perfectly reproduced in long distance communication (as opposed to analogue signals that are inevitably impacted by noise).- 1 --Mobile phones have had a significant impact on telephone networks. Mobile phone subscriptions now outnumber fixed-line subscriptions in many markets. Sales of mobile phones in 2005 totalled 816.6 million with that figure being almost equally shared amongst the markets of Asia/Pacific (204 m), Western Europe (164 m), CEMEA (Central Europe, the Middle East and Africa) (153.5 m), North America (148 m) and Latin America (102 m). In terms of new subscriptions over the five years from 1999, Africa has outpaced other markets with 58.2% growth. Increasingly these phones are being serviced by systems where the voice content is transmitted digitally such as GSM or W-CDMA with many markets choosing to depreciate analogue systems such as AMPS.There have also been dramatic changes in telephone communication behind the scenes. Starting with the operation of TAT-8 in 1988, the 1990s saw the widespread adoption of systems based on optic fibres. The benefit of communicating with optic fibres is that they offer a drastic increase in data capacity. TAT-8 itself was able to carry 10 times as many telephone calls as the last copper cable laid at that time and today's optic fibre cables are able to carry 25 times as many telephone calls as TAT-8. This increase in data capacity is due to several factors: First, optic fibres are physically much smaller than competing technologies. Second, they do not suffer from crosstalk which means several hundred of them can be easily bundled together in a single cable. Lastly, improvements in multiplexing have led to an exponential growth in the data capacity of a single fibre.Assisting communication across many modern optic fibre networks is a protocol known as Asynchronous Transfer Mode (ATM). The ATM protocol allows for the side-by-side data transmission mentioned in the second paragraph. It is suitable for public telephone networks because it establishes a pathway for data through the network and associates a traffic contract with that pathway. The traffic contract is essentially an agreement between the client and the network about how the network is to handle the data; if the network cannot meet the conditions of the traffic contract it does not accept the connection. This is important because telephone calls can- 2 --negotiate a contract so as to guarantee themselves a constant bit rate, something that will ensure a caller's voice is not delayed in parts or cut-off completely. There are competitors to ATM, such as Multiprotocol Label Switching (MPLS), that perform a similar task and are expected to supplant ATM in the future.Radio and televisionIn a broadcast system, a central high-powered broadcast tower transmits a high-frequency electromagnetic wave to numerous low-powered receivers. The high-frequency wave sent by the tower is modulated with a signal containing visual or audio information. The antenna of the receiver is then tuned so as to pick up the high-frequency wave and a demodulator is used to retrieve the signal containing the visual or audio information. The broadcast signal can be either analogue (signal is varied continuously with respect to the information) or digital (information is encoded as a set of discrete values).The broadcast media industry is at a critical turning point in its development, with many countries moving from analogue to digital broadcasts. This move is made possible by the production of cheaper, faster and more capable integrated circuits. The chief advantage of digital broadcasts is that they prevent a number of complaints with traditional analogue broadcasts. For television, this includes the elimination of problems such as snowy pictures, ghosting and other distortion. These occur because of the nature of analogue transmission, which means that perturbations due to noise will be evident in the final output. Digital transmission overcomes this problem because digital signals are reduced to discrete values upon reception and hence small perturbations do not affect the final output. In a simplified example, if a binary message 1011 was transmitted with signal amplitudes [1.0 0.0 1.0 1.0] and received with signal amplitudes [0.9 0.2 1.1 0.9] it would still decode to the binary message 1011 — a perfect reproduction of what was sent. From this example, a problem with digital transmissions can also be seen in that if the noise is great enough it can significantly alter the decoded message. Using forward error correction a receiver can- 3 --correct a handful of bit errors in the resulting message but too much noise will lead to incomprehensible output and hence a breakdown of the transmission.In digital television broadcasting, there are three competing standards that are likely to be adopted worldwide. These are the ATSC, DVB and ISDB standards; the adoption of these standards thus far is presented in the captioned map. All three standards use MPEG-2 for video compression. ATSC uses Dolby Digital AC-3 for audio compression, ISDB uses Advanced Audio Coding (MPEG-2 Part 7) and DVB has no standard for audio compression but typically uses MPEG-1 Part 3 Layer 2. The choice of modulation also varies between the schemes. In digital audio broadcasting, standards are much more unified with practically all countries choosing to adopt the Digital Audio Broadcasting standard (also known as the Eureka 147 standard). The exception being the United States which has chosen to adopt HD Radio. HD Radio, unlike Eureka 147, is based upon a transmission method known as in-band on-channel transmission that allows digital information to "piggyback" on normal AM or FM analogue transmissions.However, despite the pending switch to digital, analogue receivers still remain widespread. Analogue television is still transmitted in practically all countries. The United States had hoped to end analogue broadcasts on December 31, 2006; however, this was recently pushed back to February 17, 2009. For analogue television, there are three standards in use. These are known as PAL, NTSC and SECAM. For analogue radio, the switch to digital is made more difficult by the fact that analogue receivers are a fraction of the cost of digital receivers. The choice of modulation for analogue radio is typically between amplitude modulation (AM) or frequency modulation (FM). To achieve stereo playback, an amplitude modulated subcarrier is used for stereo FM.The InternetThe Internet is a worldwide network of computers and computer networks that can communicate with each other using the Internet Protocol. Any computer on the Internet has a unique IP address that can be used by other computers to route- 4 --information to it. Hence, any computer on the Internet can send a message to any other computer using its IP address. These messages carry with them the originating computer's IP address allowing for two-way communication. In this way, the Internet can be seen as an exchange of messages between computers.An estimated 16.9% of the world population has access to the Internet with the highest access rates (measured as a percentage of the population) in North America (69.7%), Oceania/Australia (53.5%) and Europe (38.9%).In terms of broadband access, Iceland (26.7%), South Korea (25.4%) and the Netherlands (25.3%) lead the world.The Internet works in part because of protocols that govern how the computers and routers communicate with each other. The nature of computer network communication lends itself to a layered approach where individual protocols in the protocol stack run more-or-less independently of other protocols. This allows lower-level protocols to be customized for the network situation while not changing the way higher-level protocols operate. A practical example of why this is important is because it allows an Internet browser to run the same code regardless of whether the computer it is running on is connected to the Internet through an Ethernet or Wi-Fi connection. Protocols are often talked about in terms of their place in the OSI reference model, which emerged in 1983 as the first step in an unsuccessful attempt to build a universally adopted networking protocol suite.For the Internet, the physical medium and data link protocol can vary several times as packets traverse the globe. This is because the Internet places no constraints on what physical medium or data link protocol is used. This leads to the adoption of media and protocols that best suit the local network situation. In practice, most intercontinental communication will use the Asynchronous Transfer Mode (ATM) protocol (or a modern equivalent) on top of optic fibre. This is because for most intercontinental communication the Internet shares the same infrastructure as the public switched telephone network.- 5 --At the network layer, things become standardized with the Internet Protocol (IP) being adopted for logi cal addressing. For the world wide web, these “IP addresses” are derived from the human readable form using the Domain Name System (e.g.72.14.207.99 is derived from ). At the moment, the most widely used version of the Internet Protocol is version four but a move to version six is imminent.At the transport layer, most communication adopts either the Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP). TCP is used when it is essential every message sent is received by the other computer where as UDP is used when it is merely desirable. With TCP, packets are retransmitted if they are lost and placed in order before they are presented to higher layers. With UDP, packets are not ordered or retransmitted if lost. Both TCP and UDP packets carry port numbers with them to specify what application or process the packet should be handled by. Because certain application-level protocols use certain ports, network administrators can restrict Internet access by blocking the traffic destined for a particular port.Above the transport layer, there are certain protocols that are sometimes used and loosely fit in the session and presentation layers, most notably the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols. These protocols ensure that the data transferred between two parties remains completely confidential and one or the other is in use when a padlock appears at the bottom of your web browser. Finally, at the application layer, are many of the protocols Internet users would be familiar with such as HTTP (web browsing), POP3 (e-mail), FTP (file transfer), IRC (Internet chat), BitTorrent (file sharing) and OSCAR (instant messaging).Local area networksDespite the growth of the Internet, the characteristics of local area networks (computer networks that run at most a few kilometres) remain distinct. This is because networks on this scale do not require all the features associated with larger networks and are often more cost-effective and efficient without them.- 6 --In the mid-1980s, several protocol suites emerged to fill the gap between the data link and applications layer of the OSI reference model. These were Appletalk, IPX and NetBIOS with the dominant protocol suite during the early 1990s being IPX due to its popularity with MS-DOS users. TCP/IP existed at this point but was typically only used by large government and research facilities. As the Internet grew in popularity and a larger percentage of traffic became Internet-related, local area networks gradually moved towards TCP/IP and today networks mostly dedicated to TCP/IP traffic are common. The move to TCP/IP was helped by technologies such as DHCP that allowed TCP/IP clients to discover their own network address —a functionality that came standard with the AppleTalk/IPX/NetBIOS protocol suites.It is at the data link layer though that most modern local area networks diverge from the Internet. Whereas Asynchronous Transfer Mode (ATM) or Multiprotocol Label Switching (MPLS) are typical data link protocols for larger networks, Ethernet and Token Ring are typical data link protocols for local area networks. These protocols differ from the former protocols in that they are simpler (e.g. they omit features such as Quality of Service guarantees) and offer collision prevention. Both of these differences allow for more economic set-ups.Despite the modest popularity of Token Ring in the 80's and 90's, virtually all local area networks now use wired or wireless Ethernet. At the physical layer, most wired Ethernet implementations use copper twisted-pair cables (including the common 10BASE-T networks). However, some early implementations used coaxial cables and some recent implementations (especially high-speed ones) use optic fibres. Optic fibres are also likely to feature prominently in the forthcoming 10-gigabit Ethernet implementations. Where optic fibre is used, the distinction must be made between multi-mode fibre and single-mode fibre. Multi-mode fibre can be thought of as thicker optical fibre that is cheaper to manufacture but that suffers from less usable bandwidth and greater attenuation (i.e. poor long-distance performance).- 7 --电信现代运营电话在一个模拟电话网络, 来电者通过交换机与对方进行不同的电话交流｡开关在两用户间形成一个电气连接,其参数是由来电者按键时的电气特性决定的｡一旦连接,来电者的声音通过来电端处的电话听筒转化为电信号｡然后电信号通过网络发送到另一端的用户,并通过小型扬声器将信号转化为声音｡有一个单独的电气连接用于进行转换,以使用户交谈｡固定电话,在多数居民区是模拟电话,那就是,发言者的声音,直接决定着信号的电压｡虽然距离短,来电可能会被作为模拟信号的端到端信号处理,越来越多电话服务供应商是适度的在传输前将模拟信号数字化以便传输,之后转为模拟信号以便接收｡它的优势是,数字化语音数据可以从互联网上以数字形式传输,而且可以完全转载于远程通信｡(对比来看,模拟信号无可避免会受到噪声影响｡) 手机已对电话网络产生了重大影响｡移动电话用户现在在许多市场超过了固定线路用户｡手机销量在2005年总额为8.166亿,被一下数字平分,其中亚洲/太平洋(2.04亿),西欧(1.64亿),cemea(中欧,中东和非洲)(1.535亿),北美(1.48亿)和拉丁美洲(1.02亿)｡在从1999年之后的五年时间内新增用户来看,非洲已以58.2 %的增长超过了其他地区的市场｡手机逐渐采用如GSM或W-CDMA这些可以数字化传输语音信号的系统,从而使AMPS这样的模拟系统衰落｡电话通信也隐约地有了戏剧性的变化｡开始运作的TAT-8(跨大西洋传输电缆)始于1988年, 20世纪90年代见证了基于光纤系统的普及｡光纤传输的优势在于其所提供的数据容量的急剧增加｡TAT-8可以传输相当于同轴电缆电话10倍的数据,而现在的光纤能传输25倍于TAT-8的数据｡数据能力的增加是由于几个因素:第一,光纤体积远小于其他竞争技术｡第二,他们不受到串扰这意味着数百条光纤可以很容易地捆绑在一个单一的电缆内｡最后,复用技术的改善导致了单条光纤数据容量的指数增长｡基于现代光纤网络的通信是一项称为异步传输模式( ATM )的协议｡如第二段所说,ATM协议允许为并排的数据传输｡它适用于公共电话网络,因为它建立了通过网络数据通道并以此进行通信｡传输协议基本上是一个用户与网络之间的协议,它规定了网络如何来处理数据;如果网络不能满足条件的传输协议,它不接受连接｡这很重要,因为电话可以通过协议,保证自己的恒定比特率,这将确保来电者的声音,不是延迟的部分或完全切断｡ATM的竞争对手,如多标签交换(MPLS),执行类似的任务,并可望在未来取代ATM｡电台和电视台在一个广播系统,中央高功率广播塔传输高频率的电磁波,到众多的低功率接收器上｡由广播塔发送的高频率波由信号调制且该信号载有视频或音频信息｡接收天线稍作调整，以提取高频率波,解调器用来恢复载有视力或音频信息的信号｡广播信号可以是模拟(信号多种多样,载有信息且连续)或数字(信息作为一套离散值,可以编码)｡广播媒体业正处于发展中一个关键的转折点,许多国家都从模拟发展到数字广播｡此举是可使生产更经济,更快且更能够集成电路｡与传统的模拟广播相比,数字广播最大的优势是,他们防止了一些投诉｡对电视来说,这包括消除问题,如雪花屏,重影和其他失真｡这些发生原因,是因为模拟传输的性质,这意味着噪声干扰会明显影响最后的输出｡数字传输,克服了这个问题,因为接收时数字信号变为离散值,这样小扰动不影响最终输出｡举一个简单的例子,一个二进制信息1011,已与信号的振幅[ 1.0 0.0 1.0 1.0 ]调制,并收到信号的振幅[ 0.9 0.2 1.1 0.9 ]它将仍然解码为二进制信息1011-一个完美原码再现｡从这个例子可以看出,数字传输也由一个问题,如果噪音足够大,它可以大大改变解码信息｡使用前向错误校正接收器可以在最终结果中纠正少数比特错误,但太多的噪音将导致难以理解的输出,因此,传输失败｡在数字电视广播中,有3个相互竞争的标准,很可能是全世界公认的｡它们是ATSC标准,DVB标准和ISDB标准;通过这些标准,到目前为止,应用于标题地图｡所有这三个标准,使用MPEG - 2 视频压缩｡ATSC标准采用杜比数字AC - 3音频压缩,ISDB利用先进音频编码( MPEG - 2的第7部分),而DVB没有音频压缩标准,但通常使用MPEG - 1第3部分第2层｡不同标准所用的调制方式也有所不同｡在数字音频广播中,标准更为统一,几乎所有国家都选择采用数字音频广播的标准(也称为作为尤里卡147标准)｡也有例外,美国已选择采用高清广播｡高清广播,不同于尤里卡147 ,它是基于称为在带内通道传输的传输方法,这使数字化信息,进行“背驮式”AM或FM模拟传输｡然而,尽管数字化迫在眉睫,模拟接收机仍然普遍应用｡模拟电视仍然传送几乎所有国家｡美国希望于2006年12月31日之前结束模拟广播;不过,最近又推到2009年2月17日｡对于模拟电视,有三个标准在使用中｡它们是PAL制式,NTSC制式和SECAM制式｡模拟电台,切换到数字变得更加困难,因为模拟接收器只占数字接收机的一小部分成本｡模拟电台调制方式通常采用AM(幅度调制)或FM(频率调制)｡为实现立体声播放,振幅调制副载波用于立体声调频｡互联网互联网是一个全球计算机组成的网络,也是一种用IP联系在一起的计算机网络｡在互联网上的任何一台计算机都有一个唯一的IP地址,其他计算机可以用其进行路由选择｡因此,在互联网上,任何一台电脑可以通过IP地址传送讯息给任何其他的计算机｡这些带有计算机IP地址的信息,允许计算机之间双向沟通｡这样一来,互联网可以被看作是一个计算机之间信息的交换｡据估计,16.9 %的世界人口已经进入互联网且具有最高访问率(以人口百分比衡量),它们在北美地区(69.7 %),大洋洲/澳大利亚(53.5%)和欧洲(38.9%)｡在宽带接入方面,冰岛(26.7%),韩国(25.4%)和荷兰(25.3 %)世界领先｡互联网的成功,部分是因为协议管理计算机和路由器如何互相沟通｡计算机网络通信本身的性质,有助于分层实现,此时,协议栈中的各个独立协议或多或少独立于其他协议｡这使得低级别的协议适应网络的情况,而不影响高层协议的实现｡一个实际的例子可以说明它的重要性,因为它允许一个互联网浏览器上运行相同的代码，不管运行的计算机连接到互联网是通过以太网还是通过Wi - Fi连接｡协议经常以其在OSI参考模型中的位置命名,1983年为第一步,也是一次不成功的尝试,它试图建立一个普遍采用的网络协议套件｡对于互联网来说,物理介质和数据链路层协议可以不同的数倍包遍历全球｡这是因为互联网对所用的物理介质或数据链路协议没有限制｡这导致媒体和协议的应用,它们最适合本地网络的情况｡在实践中,多数洲际通讯将使用异步转移模式( ATM )协议(或一个现代的替代物)并辅以光纤｡这是因为,对于大多数的洲际通信来说,互联网与公共交换式电话网络一样拥有相同的基础设施｡在网络层,适用于逻辑寻址的IP开始标准化｡在万维网上,这些“IP地址”来自通过域名系统处理的人类可读格式(例如72.14.207.99是来自)中｡目前,使用最广泛的版本的互联网协议是版本 4 ,但向版本六过渡已是迫在眉睫｡在传输层大部分通信采用的是传输控制协议(TCP)或用户数据报协议(UDP)｡TCP是基本协议,每条来自其他计算机的消息均需采用TCP,而UDP只有在有利时才会被采用｡有了TCP,数据包若在它们置于更高层次前丢失或乱序,它们会被重发｡有了UDP,数据包丢失时会乱序,也不会重发｡TCP和UDP数据包携带端口以便指出数据包应交由哪些应用程序或进程｡因为某些应用级协议使用某些端口,网络管理员可以通过阻断某一特定端口为目的端口的传输限制上网｡在传输层之上,有一些协议会用到并适当应用于会话层和表示层,最显着的是安全套接层(SSL)和传输层安全(TLS)协议｡这些协议,确保双方之间传输的数据仍然完全保密并且一方或另一方在使用时,挂锁出现于Web浏览器的底部｡最后,在应用层,有很多的协议为互联网用户所熟悉,如HTTP ( Web浏览) , 的POP3 (电子邮件),FTP (档案传输),IRC (网上聊天),BitTorrent(文件共享)和OSCAR(即时通讯)｡局域网不看互联网的发展, 仅局域网的特点(运行于几公里内的计算机网络)仍然明显｡这是因为这种规模的网络并不需要所有与较大的网络有关的功能,因此往往更具成本效益和高效率｡在二十世纪八十年代中期,几个协议套件的出现,填补了OSI参考模型中数据链路层和应用层之间的空隙｡如AppleTalk,IPX和NetBios与20世纪90年代初占主导地位,因MS-DOS而广受欢迎的协议套件IPX｡而TCP / IP,在这一点上,通常只用于大型政府和研究设施｡随着互联网的受欢迎程度的增长以及较大的流量与互联网逐渐相关,局域网逐步走向TCP / IP｡今天的网络大多用于TCP / IP流量是常见的｡向TCP / IP的转变由如允许的TCP / IP客户发现自己的网络地址的DHCP的技术支撑,而这与A ppleTalk,IPX/和N etBIOS协议套件以其成为标准｡在数据链路层,最现代的局域网偏离互联网｡而异步转移模式(ATM)或多协议标签转换(MPLS)技术是典型的数据链路协议,适用于较大的网络｡以太网和令牌环网是典型的局域网数据链路协议｡这些协议不同于前协议,因为它们更简单(例如,它们省略了服务质量保证等功能) ,并提供碰撞预防｡双方的这些差异,是基于经济成本的考虑｡尽管令牌环在80年代和90年代有了一定的普及,但是现在几乎所有的局域网使用有线或无线以太网｡在物理层,大多数有线以太网实现使用铜双绞线电缆(包括常用的10 Base-T的网络)｡然而,一些早期的实现使用同轴电缆,而最近的一些实现(特别是超高速的)使用光纤｡光纤也可能在即将到来的10千兆以太网的实现中有着出色的表现｡用光纤时,必须对多模光纤和单模光纤加以区分｡对于制造商来说,多模光纤可以被认为是便宜的厚光纤,但只有较少可用的带宽和更大的衰减(即较差的长途性能)｡。
电子信息工程通信外文翻译外文文献英文文献EDA的发展及VHDL的应用
The Summary of the VHDLThe VHDL English full name is the Hardware Description Language of the Integrated Circuit of the Very-High-Speed, birth in 1982. At the end of 1987, the VHDL is con firmed by the IEEE and American Ministry of National Defense to describe Ianguage for the sta ndard hardware. Announ ced VHDL sta ndard edition from the IEEE, IEEE-1076(call 87 versi ons) after, the each EDA compa ny released own VHDL desig n en vir onment one after another, or declared that the own design tool can connect with VHDL. Henceforth, the VHDL desig n realm to get to exte nsively accept in the electr oni cs, and gradually replaced an origi nally not- sta ndard hardware descripti on Ian guage. In 1993, the IEEE carried on to revise to the VHDL, describe ability to expa nd a VHDL contents from higher abstract layer and the system, ann ou need the VHDL of new editio n, n amely IEEE sta ndard of 1076-1993 editi on s, .(call 93 versi on s)Now, VHDL and Verilog are the in dustrial sta ndard hardware description of the IEEEs Ianguage, and get support of numerous EDA companies, at electr onics engin eeri ng realm, have become in gen eral use hardware to describe Ian guage. In fact, i n the new cen tury, the VHDL will start to un dertake a greatly part of nu merical system design mission at the Verilog Ianguage. The VHDL Ianguage is a kind of deluxe Ian guage which used for an electric circuit desig n. It expects to appear after the 80's of.BE.At the beginning come out by American Ministry of National Defense development to provide the America n solider with the credibility which uses to raise a desig n with cut one kind of developme nt period to use the scope smaller desig n Ian guage.All of VHDL English write BE: The Description Language of the VHSIC (the Speed In tegrated of the Very High Circuit) Hardware. Tran slati ng into Chin ese is soon extremely high the descriptio n Ian guage of the in tegrated circuit hardware. So it is of the applicati on mai nly is an applicatio n in the desig n of nu merical electric circuit. Curre ntly, it is in the applicati on most in Chi na is the desig n which uses in the FPGA/CPLD/EPLD. Certa in ly in some un its with stron ger real function s, it is also use to desig n ASIC.The VHDL mainly used for the structure, behavior which describes num cal system, fun cti on with connection. In additi on to impl ying many Ian guages sentence which have a hardware character, VHDL Ianguages forms and description style and sentence con struct ion are very similar at gen eral calculator deluxe Ian guage. VHDL procedurestructure characteristics is an engineering design, or all that the design entity(can be a component, an electric circuit mold piece or a system) is divided into exterior(or call but part, and port) with inner part(or call to can't see part), since invo Ive internal function and calculate way of en tity to complete part. At one desig ned en tity to defi ne exterior in terface after, once it internaldevelopme nt completi on after, other desig ns can directly adjust touse this en tity. This ki nd of desig n will en tity to be divided in to a little bit basic VHDL system that is a VHDL system in side the con cept of outside part desig n of a little bit basic and other hardware describe the Ianguage compare and the VHDL has a following characters: The function is strong and the design be vivid. The VHDL has the function strong Ianguage structure, can describe a complicated logic control with the simple and direct and explicit source code. It has a multi-layer desig n descripti on fun cti on, in multiple layers thi n turn, fin ally directly born electric circuit class descripti on. The VHDL supports synchronous electric circuit, differenee's tread electric circuit with random the design of electric circuit, this be the other hardware descripti on although the Ian guage can't compare to. The VHDL still supports various desig n method, since support from the bottom upward desig n, support aga in from the desig n of crest declivity; since the support mold piece tur ns a design, support layer's turn a design again. Support extensively and be easy to a modificatio n. Because the VHDL has already become IEEE sta ndard the norm of hardware description Ianguage, most EDA tools almost support VHDL currently, this is VHDL of further expansion with extensively applied lay foundation. In the design process of the hardware electric circuit, the mai n desig n docume nt is the source code which writes with the VHDL, the VHDL easily reads with the structure turn, so be easy to a modification desig n.The strong system hardware describes ability. The VHDL has a multi-layer design description function, since can describe system class electric circuit, can describe door class electric circuit again. And description can adopt a behavior description, deposit a machine to deliver description or structure description, can also adopt the hybrid descripti on of threes mixture. Moreover, VHDL support is in ertial to delay and deliver to delay, can also accurately build up hardware electric circuit model. VHDL support prepare defi nite of with from defi niti on of data type, bring hardware descripti on a bigger freedom degree, make desig n the pers onnel can expedie ntly establish the system model of high time.The in depe ndence is at the desig n of spare part, have nothing to do with the craft. Don'tneed to consider a choice completion the spare part of design first while designing a pers onnel to carry on a desig n with the VHDL, can concen trate en ergy to carry on desig n of excelle nt tur n.When the desig n descripti on complete after, can carry out its fun cti on with various different spare part structure very strong transplantation ability. The VHDL is a kind of hardware descripti on for sta ndardize Ian guage, the same of desig n descripti on can be support by the differe nt tool and make to desig n to describe of the tran spla ntati on make possible.Be easy to share and reply to use. The VHDL adopti on can build up various mold piece that can again make use of according to the design method of database (Library). These canned in advanee design or use to design a medium backup mold a piece before and depositted these to the database in, can be in lately of the desig n carry on replyi ng to use, can make the design result be design the personnel's to carry on exchanges and share, decrease hardware electric circuit desig n.("Compared with other hardware description Ianguages, the VHDL have stronger behavior descriptio n on ability, come to a decisi on him to become a system desig n realm the best hardware a descriptio n Ian guage thus. The strong behavior descripti on ability is to avert from con crete spare part structure and describe and desig n importa nt assura nee of large-scale electr onics system from the logic behavior.(2) The VHDL be abundant of imitate true Ian guage sentence and database fun cti on, make in any big system of the desig n can in spect a function possibility of desig n the system in early days, can carry on imitati ng true emulati on to the desig n at any time.(3) The ability and procedure structure of the behavior descripti on with lexical VHDL come to a decisi on the decompositi on that he has to support a large-scale desig n with have already have desig n of aga in make use of fun cti on. Meet the market dema nding large-scale system efficie ntly, the completi on of the high speed has to in clude many people the several gen erati on hair set eve n together and abreast works and the n can carry out.(4) For use the desig n of an assura nee of VHDL completi on, can make use of EDA toolto carry on logic comprehensive with excellent turn, and auto of the VHDL describe the desig n cha nge into the door class net form.(5)The descripti on of VHDL to desig n have opposite and in depe ndent, the desig n can not un dersta nd the structure of hardware and n eed not man age the target spare part that the end desig n carry out, either is what, but carry on an in depe ndent desig n.VHDL 的介绍VHDL 的英文全名是Very-High-Speed In tegrated Circuit Hardware Description Language,诞生于1982年。
[电子信息工程] 本科论文英文文献翻译
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外文资料翻译学院：电子工程学院系（专业）：电子信息工程班级：电子061姓名：学号:一：外文原文3G TECHNOLOGYAlthough the technology behind 3G may seem complicated, the ways in which 3G will affect all of our lives are easy to imagine. Just imagine having a combined camera，videocamera，computer, stereo，and radio included in your mobile phone. Rich-media information and entertainment will be at your fingertips whenever you want anywhere there is a wireless network。
Mobile communication is moving from simple voice to rich media, where we use more of our senses to intensify our experiences.But not all of this will happen at once. 3G is an evolution to a communications ideal that no one completely understands yet. What we do know is that mobile multimedia will hit the Japanese markets in 2001，and Europe and North America will follow soon after。
3G brings together high-speed radio access and IP-based services into one, powerful environment. The step towards IP is vital. IP is packet-based，which in simple terms，means users can be ”on line” at all times，but without having to pay until we actually send or receive data. The connectionless nature of IP also makes access a lot faster：file downloads can take a few seconds and we can be connected to our corporate network with a single click.3G introduces wideband radio communications, with access speeds of up to 2Mbit/s. Compared with today's mobile networks，3G will significantly boost network capacity — so operators will be able to support more users, as well as offer more sophisticated services.3G - At home3G is going to affect our home and social lives in many ways. The services that 3G enables will help us to manage our personal information，simplify tasks such as grocery shopping，make better use of our time and offer services that are just fun to use。
电子信息 外文文献译文
XXXX学院毕业设计（论文）外文参考文献译文本2012届原文出处A Novel Cross-layer Quality-of-service ModelFor Mobile AD hoc Network毕业设计(论文)题目基于COMNETIII的局域网的规划与设计院（系）电气与电子信息学院专业名称电子信息工程学生姓名学生学号指导教师A Novel Cross-layer Quality-of-service ModelFor Mobile AD hoc NetworkLeichun Wang, Shihong Chen, Kun Xiao, Ruimin Hu National Engineering Research Center of Multimedia Software, Wuhan UniversityWuhan 430072, Hubei, chinaEmail:******************Abstract:The divided-layer protocol architecture for Mobile ad hoc Networks (simply MANETs) can only provide partial stack. This leads to treat difficulties in QoS guarantee of multimedia information transmission in MANETs, this paper proposes Across-layers QoS Model for MANETs, CQMM. In CQMM, a core component was added network status repository (NSR), which was the center of information exchange and share among different protocol layers in the stack. At the same time, CQMM carried out all kinds of unified QoS controls. It is advantageous that CQMM avoids redundancy functions among the different protocol layers in the stack and performs effective QoS controls and overall improvements on the network performances.Keyword: Cross-layers QoS Model, Mobile Ad hoc Networks (MANETs), Network Status Repository (NSR), QoS Controls.1 introductionWith the rapid development of multimedia technologies and the great increase of his bandwidth for personal communication, video and video services begin to be deployed in MANETs. Different from static networks and Internet, multimedia communications in MANETs such as V oice and Video services require strict QoS guarantee, especially the delay guarantee. In addition, communication among different users can be integrated services with different QoS requirements. These lead to great challenges in QoS guarantee of multimedia communication in MANETs. There are two main reasons in these: 1) MANETs runs in atypical wireless environment with time-varying and unreliable physical link, broadcast channel, and dynamic and limited bandwidth and so forth. Therefore, it can only provide limited capability for differentiated services with strict QoS requirements [1].2) It is difficult that traditional flow project and access control mechanism are implemented because of mobility, multiple hops and self-organization of MANETs.At present, most researches on QoS based on traditional divided-layer protocol architecture for MANETs focus on MAC protocol supporting QoS [2], QoS routingprotocol [3] and adaptive application layer protocol with QoS support [4], and so on. It is avoid less that there will be some redundancies on functions among the different protocol layers in the stack. This will increase the complexity of QoS implementation and cause some difficulties in overall improvement on the network performances. Therefore, it is not suitable for MANETs with low processing abilityIn recent years, the cross-layers design based on the partial protocol layers in MANETs was put forward.[1] proposed the mechanism with QoS guarantee for heterogeneous flow MAC layer.[5,6,7,8] did some researches on implementing video communication with QoS guarantee by exchange and cooperation of information among a few layers in MANETs. These can improve QoS in MANETs’communication to some extent. However, MANETs is much more complex than wired system and static network, and improvements on QoS guarantee depend on full cooperation among all layers in the protocol stack. Therefore, it is difficult for the design to provide efficient QoS guarantee for communication and overall improvements on the network performances in MANETs.To make good use of limited resources and optimize overall performances in MANETs, this paper proposes a novel cross-layer QoS model, CQMM, where different layers can exchange information fully and unified QoS managements and controls can be performed.The rest of the paper is organized as follows. CQMM is described in section 2 in detail. In section 3, we analyze CQMM by the comparison with DQMM.The section 4 concludes the paper.2. A CROSS-LAYER QOS MODEL FOR MANETS-CQMM2.1 Architecture of CQMMIn MANETs, present researches on QoS are mostly based on traditional divided-layer protocol architecture, where signals and algorithms supporting QoS are designed and implemented in different layers respectively, such as MAC protocol supporting QoS in data link layer [9], routing protocol with QoS support in network layer[10.11],and so forth. It can be summarized as A Divided-layer QoS Model for MANETs, DQMM (see fig.1).In DQMM, different layers in the protocol stack are designed and work independently; there are only static interfaces between different layers that are neighboring in logic; and each protocol layer has some QoS controls such as error control in logic link layer, congestion control in network, etc. On the one hand, DQMM can simplify the design of MANETs greatly and gain the protocols with high reliability and extensibility. On the other one, DQMM also has some shortcomings: 1) due to the independent design among he different protocol layers, there are some redundancy functions among the different protocollayers in the stack, 2) it is difficult that information is exchanged among different layers that are not neighboring in logic, which leads to some problems in unified managements, QoS controls and overall improvements on the network performances.Fig.1Therefore, it is necessary that more attention are focused on the cooperation among physical layer data link layer, network layer and higher when attempting to optimize performances of each of layer in MANETs. For this reason, we combine parameters dispersed in different layers and design a novel cross-layer QoS model, CQMM, to improve the QoS guarantee and the overall network performances. The architecture of CQMM is provided in fig 2From fig.2, it can be seen that CQMM keeps the core functions and relative independence of each protocol layer in the stack and allows direct information exchange between two neighboring layers in logics to maintain advantages of the modular architecture .On the basic of these, a core component is added in CQMM, Network Status Repository (simply NSR).NSR is the center, by which different layers can exchange and share information fully. On the one hand, each protocol layer can read the status information of other protocol layers from NSR to determine its functions and implementation mechanisms. On the other one, each protocol layer can write its status information to NSR that can be provided with other layers in the protocol stack. In CQMM, the protocol layers that are neighboring in logics can exchange information directly orindirectly by NSR, and the protocol layers that are not neighboring in logics can exchange information using cross-layer ways via NSR. Therefore, information exchange is flexible in CQMM.All kinds of QoS controls in CQMM such as management and scheduling of network resources, network lifetime, error control, and congestion control and performance optimization and so on are not carried out independently. On the contrary, CQMM is in charge of the unified management and all QoS controls by the cooperation among different protocol layers in the stack. Each QoS control in MANETs is related to all layers in the protocol stack, and also constrained by all layers in the stack. The results of all QoS operations and managements are fed back to the different layers and written back to NSR, which will become the parameters of all kinds of QoS controls in MANETs.2.2 protocol design in CQMMIn CQMM, the protocol designs aims at the full and free information exchange and cooperation among different protocol layers to avoid possible redundancy functions when maintaining the relative independence among different layers and the advantages of the modular architecture.Physical layer: Physical layer is responsible for modulation, transmission and receiving of data, and also the key to the size, the cost and the energy consumption of each node in MANETs. In CQMM, the design of physical layer is to choose the transmission media, the frequency range and the modulation algorithm wit the low cost, power and complexity, big channel capability and so on, according to the cost of implementation, energy constraint, and capability and QoS requirements from high layer.Data link layer: The layer is low layer in the protocol stack and can be divided into two sub-layers: logic link sub-layer and MAC sub-layer. Compared with high layers, data link layer can sense network status in MANETs earlier such as the change of channel quality, the network congestion and so on. Therefore, on the one hand data link layer can perform the basic QoS controls such as error control and management of communication channel. On the other one, the layer can be combined with high layers to establish, choose and maintain the routing faster, prevent the congestion of the network earlier, and choose appropriate transport mechanisms and control strategies for transport layer.Network layer: The design and implementation of network layer protocol in CQMM is to establish, choose and maintain appropriate routings by taking into consideration the power, the cache, the reliability of each node in a routing. QoS requirements of services from high layer such as the bandwidth and the delay, and implementation strategies oferror control in logic link sub-layer and the way of the channel management in MAC sub-layer.Transport layer: In CQMM, the protocol design of transport layer needs to be aware of both functions and implementation mechanism of lower layers such as the way of error control in data link layer, the means to establish, choose and maintain routing in the network layer, and QoS requirements from the application layer, to determine corresponding transmission strategies. In addition, the transport layer also needs to analyze all kinds of events from low layers such as the interrupt and change of the routing and the network congestion, and then respond properly to avoid useless sending data.Application layer: There are two different strategies in the design of the application layer: 1) differentiated services. According to the functions provided by the low layers applications are classed as the different ones with different priority levels. 2) Application-aware design. Analyze specific requirements of different applications such as the bandwidth, the delay and the delay twitter and so on, and then assign and implement the functions for each layer in the protocol stack according to the requirements.2.3 QoS Cooperation and Management in CQMMIn CQM, the core of QoS cooperation and management is that NSR acts as the exchange and share center of status information in protocol stack, and by the full exchange and share of network status among different protocol layers the management and scheduling of the network resources and the overall optimization of the network performances can be implemented effectively. The management and scheduling of the network resources, the cross-layer QoS cooperation and the overall optimization of the network performances.Management and scheduling of network resources: Network resources include all kinds of resources such as the cache, the energy and the queue in each node, and the communication channel among nodes and so froth. In CQMM, the management and scheduling of the network resources are not to the unified management and scheduling of the network resources and full utilization of limited resources in order to increase the QoS of all kinds of communication.QoS cooperation and control: In CQMM, all kinds of QoS controls and cooperation such as the rate adaptation, the delay guarantee and the congestion control and so on, are not implemented by each layer alone, but completed through the operation of all layers in the protocol stack. For example, the congestion in MANETs can be earlier prevented and controlled by the cooperation among different layers such as ACK from MAC sub-layer,the routing information and the loss rate and delay of package from network layer, and the information of rate adaptation in transport layer and so on.Performances Optimization: In CQMM, the optimization of the network performances aims to establish a network optimization model constrained by all layers in the protocol architecture and finds the “best”ways according to the model in order to improve the overall performances in MANETs.3. ANALYSIS OF CQMMPresent QoS models for MANETs can mainly be classed as a QoS model based on traditional divided-layer architecture DQMM and a cross-layer QoS model proposed by this paper CQMM. QoS model used by [1, 5-8] is to some extent extended on the basis of DQMM in nature. Here, we only compare CQMM with DQMM3.1 Information ExchangeDifferent protocol architecture and principle between CQMM lead to great differences in the means, the frequency, the time and the requirement of the information exchange, (see table 1)From Table 1, it can be seen that compared wit DQMM CQMM has some advantages: 1) more flexible information exchange. Neighboring layers can information by the interfaces between layers or NSR, and crossing layers may exchange information through NSR; 2) simpler transform in information format. Different layers can exchange information by NSR, so these layers only need to deal with the format transform between the layers and NSR;3)lower requirements. The protocol layers can read them in proper time Information from different protocol layers temporarily stored in NSR, so the layers exchanging information are not required to be synchronous in time;4) more accurate control. NSR in CQMM can store information of some time from the different layers, which is advantageous to master the network status and manage the network more accurately. However, these require higher information exchange frequencies among the different layers,, more processing time of each node, and more communication among them.。
电子信息工程论文(英文)【精选文档】
Electronic and information engineering is the application of the computer and modem technology for electronic information control and information processing the discipline， the main research information acquisition and processing，electronic equipment and information system design, development, application and integration. Now, electronic and information engineering has covered many aspects of the society，like telephone exchange station how to deal with various phone signal, a mobile phone is how to transfer our voice even image， the network around us how to transfer data, and even of the army of the information age how to confidential information transmission， are involved in electronic and information engineering application technology。
We can through some basic knowledge learning know these things， and able to apply more advanced technology in new product research and electronic and information engineering is professionalThis program is to cultivate master the modern electronic technology theory, familiar with electronic system design principle and design method， have stronger computer, foreign language and corresponding engineering technology application ability, facing the electronic technology, automatic control and intelligent control, computer and network technology， electronic, information，communication field of broad caliber， the high quality, comprehensive development of integrated with innovation ability engineering technology talent development.Electronic information engineering major is learning the basic circuit of knowledge, and master the computer processing with the method of information. The first to have solid mathematical knowledge, for physics requirement is high， and mainly electrical； To learn many circuit knowledge, electronic technology, signal and system, computer control principle， communication principle，basic courses. Learning in electronic and information engineering design, to themselves have to connect with computer some circuit experiment, to operate and use tools requirements is also higher。
数字电路 电路电信 外文翻译 外文文献 英文文献
FEATURES
Small size
Easy construction
Low cost.
Simple adjustment.
Easy to read from a distance.
Few external components.
The DVM technology
Front side
Copyright of this circuit belongs to smart kit electronics. In this page we will use this circuit to discuss for improvements and we will introduce some changes based on original schematic
Schematic (fixed16-11-09)
7-segment display pinout MAN6960
An Analogue to Digital Converter, (ADC from now on) is better known as a dual slope converter or integrating converter. This type of converter is generally preferred over other types as it offers accuracy, simplicity in design and a relative indifference to noise which makes it very reliable. The operation of the circuit is better understood if it is described in two stages. During thefirst stage and for a given period the input voltage is integrated, and in the output of the integrator at the end of this period, there is a voltage which is directly proportional to the input voltage. At the end of the preset period the integrator is fed with an internal reference voltage and the output of the circuit is gradually reduced until it reaches the level of the zero reference voltage. This second phase is known as the negative slope period and its duration depends on the output of the integrator in the first period. As the duration of the first operation is fixed and the length of the second is variable it is possible to compare the two and this way the input voltage is in fact compared to the internal reference voltage and the result is coded and is send to the display.
电子信息工程数据库管理中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)译文：数据库管理数据库（有时拼成Database）也称为电子数据库，是指由计算机特别组织的用下快速查找和检索的任意的数据或信息集合。
数据库与其它数据处理操作协同工作，其结构要有助于数据的存储、检索、修改和删除。
数据库可存储在磁盘或磁带、光盘或某些辅助存储设备上。
一个数据库由一个文件或文件集合组成。
这些文件中的信息可分解成一个个记录，每个记录有一个或多个域。
域是数据库存储的基本单位，每个域一般含有由数据库描述的属于实体的一个方面或一个特性的信息。
用户使用键盘和各种排序命令，能够快速查找、重排、分组并在查找的许多记录中选择相应的域，建立特定集上的报表。
数据库记录和文件的组织必须确保能对信息进行检索。
早期的系统是顺序组织的（如:字母顺序、数字顺序或时间顺序）；直接访问存储设备的研制成功使得通过索引随机访问数据成为可能。
用户检索数据库信息的主要方法是query（查询）。
通常情况下，用户提供一个字符串，计算机在数据库中寻找相应的字符序列，并且给出字符串在何处出现。
比如，用户必须能在任意给定时间快速处理内部数据。
而且，大型企业和其它组织倾向于建立许多独立的文件，其中包含相互关联的甚至重叠的数据，这些数据、处理活动经常需要和其它文件的数据相连。
为满足这些要求，开发邮各种不同类型的数据库管理系统，如：非结构化的数据库、层次型数据库、网络型数据库、关系型数据库、面向对象型数据库。
在非结构化的数据库中，按照实体的一个简单列表组织记录；很多个人计算机的简易数据库是非结构的。
层次型数据库按树型组织记录，每一层的记录分解成更小的属性集。
层次型数据库在不同层的记录集之间提供一个单一链接。
与此不同，网络型数据库在不同记录集之间提供多个链接，这是通过设置指向其它记录集的链或指针来实现的。
网络型数据库的速度及多样性使其在企业中得到广泛应用。
当文件或记录间的关系不能用链表达时，使用关系型数据库。
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电子信息工程电路编程中的AT89C51单片机
译文标题电路编程中的AT89C51单片机
AT89C51 In-Circuit Programming 原文标题
作者Robert W.Sparks等译名国籍美国斯帕克等W.罗伯特
Atmel Corporation
原文出处
摘要本应用说明的是ATMEL公司AT89C51的电路可编程闪存的微控制器。
为在电路可编程AT89C51的应用提出了与应用程序相关的例子，它的修改要求支持在线编程。
这种方法显示在该应用程序中的AT89C51单片机可通过商业电话线远程改编。
本应用笔记中描述的电路，仅支持5伏电压下编程，需要使用一个AT89C51-XX-5。
标准A T89C51的需要12伏电压。
该应用程序的软件可从ATMEL下载。
总论
当不在进行程序设计的时候，在电路设计中的AT89C51设计将变得透明化。
在编程期间必须重视EA/VPP这一脚。
在不使用外部程序存储器的应用程序中，这脚可能会永久接到VCC。
应用程序使用的外部程序存储器要求这一脚为低电平才能正常运行。
RST在编程期间必须为高电平。
应该提供一种方法使得电路通入电源以后，使RST代替主要的复位电路起到复位的作用。
在编程过程中，PSEN必须保持低电平，在正常运行期间绝不能使用。
ALE/ PRO在编程过程中输出低电平，在正常运行期间绝不能使用
在编程过程中AT89C5I / 端口是用于模式应用程序，地址和数据选择的，可能要该控制器从应用的电路隔离。
如何做到这一点取决于应用程序
输入端
在编程过程中，控制器必须与应用电路的信号来源隔离。
带有三个输出状态的缓冲区在应用程序之间插入电路和控制器，同时在编程时缓冲区输出三种状态。
一个多路复用器用于信号源之间进行选择，适用于任何一方的应用电路或编程控制器电路的信号
输出端
如果应用的电路可以允许端口在编程过程中的状态变化，则不需要改变电路。
如果应电路的状态，必须事先在编程过程中的保持不变，可能在控制器和应用电路中插入锁存。
存在编程期间是可用的，并保存应用程序的电路状态
应用实
如所示应用是AT89C5一个移动的显示情况。
此应用程序有在电路重新编程时结果以图表的形式显示的简单能力。
文本显示被设计作为其硬件的一部分，不能在无改编况下变化
显示的文本可DI开关选择两种模式之一中进行。
在第一种模式的时候，进入个字符从右边显示和快速移动，通过每个元素显示其在最后的装配位置的左侧。
第二个模式，信息在信息窗口中右到左移动显示。
这种模式与常常在股票价格的显示所使用的方法类似
输出包括四DL14141段的积分解码器和驱动程序的字母数字显示器。
这就生1名显示元素，每个数字0-的显示能力，是大写字母，标点符号和一些字符。
可示字符ASCII码范围20H-5F上电复位电路和一6 MH的晶体振荡器完成应用件程序。
无论外部程序存储器或外部数据存储器都时可用的
支持应用程序的修
显示了修改内部电路程序的应用
据推测，编程器在休眠时，既不会驱动，也不会加载应用程序。
由于应用程序不使用外部页5 共页1 第
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外文翻译成绩
指导教师签字
注：1。
指导教师对译文进行评阅时应注意以下几个方面：①翻译的外文文献与毕业设计（论文）的主题是否高度相关，并作为外文参考文献列入毕业设计（论文）的参考文献；②翻译的外文文献字数是否达到规定数量（3 000字以上）；③
译文语言是否准确、通顺、具有参考价值。
2。
外文原文应以附件的方式置于译文之后。
页5 共页5 第。