外文参考资料及译文封面定稿.docx

1、外文参考资料及译文封面定稿毕 业 设 计（论 文）外 文 参 考 资 料 及 译 文译文题目：Telephone exchanges the principle and development 电话交换机的原理以及发展 学生姓名： 毛远 学号： 0805110803 专业： 通信工程 所在学院： 信息技术学院 指导教师： 杨娟 职称： 讲师 2011年 12月 7日说明：要求学生结合毕业设计（论文）课题参阅一篇以上的外文资料，并翻译至少一万印刷符（或译出3千汉字）以上的译文。译文原则上要求打印（如手写，一律用400字方格稿纸书写），连同学校提供的统一封面及英文原文装订，于毕业设计（论文）工作开

2、始后2周内完成，作为成绩考核的一部分。Telephone exchanges the principle and development FromBrief introduction of SPC exchangesAbstract the classification of telephone exchanges 1) telephone exchange control mode is divided into the following two categories as: 1. The wiring logic control 2. Storage program control 2)

3、 according to the purposes of SPC exchanges can be divided into: audio signals, long-distance and users switch; 3) in the air way can be divided by time and switches. 4) of SPC exchanges by information transfer mode can be divided into: analog switches and digital switches. Due to the air in the net

4、work program-controlled switch (or exchange network) in air separation unit for wiring (or intersection switch array), and in the words of the general transfer and way of the exchange of analog voice signal is, and habits called program-controlled analog switches, the switch to voice the module conv

5、ersion (decoding), the user circuit is simple, and low cost, mainly used as a small capacity simulation users switch. At the general in words program-controlled switch part way to transmit and switching is analog voice signals, thus habits called digital program-controlled switch, along with the dig

6、ital communication and pulse code modulation (PCM) technology to the rapid development and application of, the advanced countries in the world since the s with great passion to developing digital program-controlled switch, through hard work, the French first in 1970 in pull nyon (Lanion) success ope

7、ned the world the first digital program-controlled exchange system was, it marked the exchange technology from the traditional analog exchange into the digital age exchange. Because digital program-controlled exchange technology and equipment of the advanced nature of the economy, the telephone exch

8、ange got into a new stage, and to open the words business, to realize comprehensive digital switching business laid a foundation, thus it has become the main direction of exchange technology, along with the microprocessor technology and special integrated circuit of the leap development, digital pro

9、gram-controlled exchange became apparent the superiority of the show. At present the production of large capacity of the ChengKongJi all for digital. Second, the role of program-controlled customer exchangers and type 1. The PBX role Users switch is industrial and mining enterprises, and other units

10、 internal organs of the telephone exchange a special switches, its basic function is complete unit interior users call each other, but also can be equipped with trunks in and out of the public telephone network access the nets part and net users call (including city calls, domestic and international

11、 long-distance calls long-distance). Because this kind of switches is special unit interior, so can be based on user needs to increase the number of additional performance to provide convenient use. So this kind switch has a greater flexibility. Users switch on the technology used is the development

12、 trend of program-controlled customer exchangers, a new digital program-controlled switch can be exchanged phone user not only the business, but also can exchange data on the words business, do a variety of business of comprehensive exchange and transmission. For each unit form integrated services d

13、igital network (ISDN) created the conditions. At present already can access ISDN users. SOPHO is the world first can deal with ISDN business comprehensive information switches, whether to provide interface or signaling completely accord with the standard way ISDN. Can firmly believes that in the fut

14、ure the ISDN nets in digital program-controlled switch will users play an important role. 2. The type of program-controlled customer exchangers Program-controlled customer exchangers have so many kinds, from a technical structure is divided into program-controlled switch and program control air user

15、s of digital subscriber switches two kinds. The former is analog voice signal to exchange, belongs to the simulation exchange category. The latter exchange of digital voice signal PCM is, is a type of digital switches. If from the use of classification, can be divided into general program-controlled

16、 customer exchangers and special program-controlled customer exchangers two kinds big. Universal used in general enterprise, institution, factories, government agencies, and the school to voice business primarily of the unit. Capacity in the general hundreds of door, and the internal traffic account

17、s for a bigger chunk of the total traffic the general of around 70%. The current domestic production of door of the 200 program-controlled air separation unit belong to the user switch this type, its characteristic is the system structure is simple, the volume is small, easy to use, cheap, less main

18、tenance. Special apply to all kinds of different units, according to each unit of special need to provide all kinds of special function. The several special separately program-controlled customer exchangers: Obvious show. At present the production of large capacity of the ChengKongJi all for digital

19、. A Shaker Chair and a Louis XV Chair The Shaker chair is a precisely crafted but unadorned object. It is amanifestation of the convictions and values of the Shaker community. Theseemphasised simplicity, a renunciation of worldly wealth and show, and anavoidance of things which might cause pride and

20、 egotistical tendencies. By contrast the Louis XV chair expresses opulence, status and luxury. A Zen Garden and the Las Vegas Strip The Zen garden is a focus for meditation and contemplation. It is anoutward expression of an inner journey. The Las Vegas Strip, by contrast, could be said to epitomise

21、 enticement,instant gratification and greed. The Citron 2CV and the Rolls Royce The Citron 2CV is a small, utilitarian car expressive of utility andeconomy. It is highly versatile, relatively inexpensive and fulfils itsfunction without luxury or pretence. The Rolls Royce expresses a very different v

22、alue system - one concernedwith power, status, conspicuous consumption and luxury. While undoubtedlya high quality product, this quality is manifested in a way which quiteexplicitly speaks of wealth, pride and vanity. The Bicycle and the Mountain-Bike The bicycle is a product which started out as a

23、simple straightforwardmeans of transport. In many places it maintains this role as a utilitarianobject which fulfils an important need. Where the bicycle is used as abasic means of transport, such as in Holland and China, it is aboutpersonal transportation and little else. In countries such as Canad

24、a and the United States, where the car is theprimary mode of transport, the bicycle is, for the most part, a leisureproduct, and its manifestation is the mountain-bike. It has moved frombeing a utilitarian product to what Lansley has referred to as apositional product1. We acquire positional goods n

25、ot necessarily fortheir intrinsic worth but according to whether other people have them.2 Human Values and Increasing Wealth The transition from a non-positional to positional product is an outwardrepresentation of a transition of values. With increasing wealth ourvalues tend to change, we move from

26、 using basic, functional products todesiring and acquiring products which have more status-orientedaccoutrements and meanings. While this has always been the case throughouthistory, in recent times the ability to acquire such products has becomepossible for a much larger proportion of the population

27、 than in the past.Since WWII more and more goods have moved from being needs-oriented, topositional or status-oriented3. This has contributed to an upward spiralof consumption, a downward spiral in terms of environmental stewardship,and a widening gap between rich and poor4. Moreover, these developm

28、entsfundamentally conflict with the perennial human values espoused by themajor religious and philosophical traditions. Perennial Human Values and Contemporary Products All the major religions extol similar ideas about the dangers of placingtoo much emphasis on possessions and material wealth - an e

29、mphasisexacerbated by an increased orientation towards TpositionalU goods.Indeed, the aspects which these traditions value could be said to be theantithesis or inverse of those values extolled by modern political andbusiness practices, and which many contemporary products embody andrepresent. Gandhi

30、 said:I asked myself what was necessary for me in order to remain absolutelyuntouched by immorality, by untruth, by what is known as political gain. I came definitely to the conclusion that if I had to serve the peoplein whose midst my life was cast and whose difficulties I was witness fromday to da

31、y, I must discard all wealth, all possessions. 5 In contrast to this, our culture promotes the very opposite view.Acquisition of material possessions is constantly encouraged bypoliticians, economists and business leaders: consumers have been on a shopping spree for cars, furniture andappliances, as

32、 well as homes. . Tim ONeill, chief economist at the Bankof Montreal, also said the return of consumers who have been hibernatingmost of this decade will boost economic growth.6 We can feel good again, say Tories.The return of the feel-good factor was hailed by the Governmentyesterday as figures showed renewed confidence in the housing market andan increased public readiness to spend on credit.Ministers said that this was the culmination of a month of good economicnews and vindication of their policies.7 People are continually being told to consu