英文翻译

第一篇：英文翻译

他的研究结果并不明朗，往往揭示出一个微弱的甚至是消极的关于留存收益的FDI与税务的反映机制。这项研究明显对哈特曼模型投出了质疑，但一直没有大的动作尝试用更好的数据或方法进行重新估计。

文献中确实体现了Slemrod（1990）的想法，他认为处理双重征税的政策可能会影响税收反应。常见的区别是不对母国以外的收入进行征税的国家之间，免征国外赚来的收入的纳税义务，以及对母公司潜在的应纳税额收取的全球性税务，但可能会采取多种方式来处理国外收入来避免跨国公司的双重征税。处理双重征税的问题有两个标准的方法，为本国提供信贷或者扣除由跨国公司取得的国外纳税收益。

当研究人员开始研究1986年美国税制改革对于在美国的外来直接投资的显著性影响时，这些税务处理办法对于影响FDI和税收分析的潜力，在研究文献中起到了至关重要的作用。斯科尔斯和欧胜（1990）推测，当美国的税率增加，美国在全球范围的跨国公司所产生的FDI可能会增加！这看似有悖常理的概念来自于认识到了信用体系，例如，跨国公司不会在全球征税系统下看到应纳税额有所增加。在另一方面，美国国内投资者（属地税制下的跨国公司）将承担增加的美国税项负债的全面冲击。随着公司在美国投标了相同的的资产，全球税收跨国公司将会变得有利并且投入更多。尽管斯科尔斯和欧胜（1990）用很简单的统计检验表明，美国外国直接投资自1986年以后的上升没有受到其它因素的控制，但是斯文森（1994年）对斯科尔斯和欧胜的假设做了更仔细的检查，通过对1986年的改革对不同产业FDI产生的不同影响进行检测，这些产业在改革后税率都发生了变化。具体来说，斯文森检查了从1979年到1991年行业面板数据，利用从1986年的税制改革后行业税率的变化，发现FDI确实随着更大的平均税率增加而增加，尤其是全球征税的国家。斯文森的研究一个令人担忧的问题是，他确定了斯科尔斯和欧胜采用平均税率数据进行检测时结果是接受假设，但使用实际税率则是拒绝原假设。奥尔巴赫和哈塞特（1993）提供了推翻斯科尔斯和欧胜假设的进一步证据，他们通过开发FDI模型来预测美国的投资类型，税制改革应该对其进行支持为了使属地纳税的跨国公司对抗全球纳税的跨国公司。特别是，他们的模型显示，属地税收跨国公司应该将更多的精力放在激励合并与收购（M＆A）的外国直接投资，而全球税收跨国公司应该已经从这样的FDI投资新设备的情况下气馁。这些数据似乎表明，1986年美国税法改革后外商直接投资的大幅增加，是由于跨国公司从全球税收国家（主要是日本和英国）推进对外直接投资。

因此，在很多方面，1986年的税制改革对FDI的影响到今天都是一个开放性问题。然而，尽管这个特定的问题如今已经有些过时了，但是给母公司提供信用的全球税收制度国的FDI应该相对而言对税率不那么敏感这个话题仍然是持续的热点。海恩斯表示（1996年）对它做出了最好的表达，根据现存文献检测了是否国家级税会影响美国内区域的FDI，从而创造性地提出了属地纳税对抗全球纳税的处理办法。以往的研究探讨国家税收对于国家FDI的分布的影响，结果并不明显（参见例如，考夫林，Terza和Arromdee，1991）。像联邦税，跨国公司根据他们在母国面临属地纳税还是全球纳税可能会对国家级税有不同的反应。海因斯（1996）的实证策略是调查FDI在美国各州的分布，并且研究比较“非信用体系”的状态下的外国投资者相对于“信用系统”下的外资投资者FDI的税收敏感度。他发现，随着税率高1％，非信用体系投资者FDI的减少比信用体系投资者FDI的减少多 9％。

综上所述，文献精细的指出了当考虑到税收对FDI的影响时，资料多的用不了。跨国公司在母国和东道国都遭遇了大量不同级别的税率和处理双重征税的政策，这能极大的改变税收对鼓励跨国公司投资的影响。正如上文所提到的，经验方法和数据样本相差甚远，因此税（以及在美国1986年的税收改革之类的）在多大程度上影响FDI仍然是显著的问题。证据似乎更有力的说明了，一个跨国公司在客国申报纳税而形成的处理国外税的信用系统是相对无关紧要的。

文献中还存在其他的弱点需要解决。首先，所有上述考察（最好）产业层面的数据模型的研究通常是属于公司层面的活动。这可以通过依靠理论来解释经验证据来制造问题。这方面最明显的例子是使用平均税率为利率变量，这在变量设置上是一个完全的错误。平均或实际税率是否作为税务义务的的测度很少被讨论，但正如作为例证的斯文森（1994）研究所说，它对FDI会产生十分不同的影响。

文献也只是最近才开始研究除企业所得税以外的其他税。例如，德赛，弗利和海因斯（2004）最近的工作论文提出的证据表明，间接营业税对FDI的影响与企业所得税对FDI的影响是一定范围内是相同的。与此类似，双边国际税收协定对FDI的影响直到最近仍然是未被开发的实证课题。关于谈判减少国家在其他事项上的代扣所得税的税收协定有成千上万个。沃德-Dreimeier（2003年）和Blonigen和Davies（2004）发现没有证据表明这些条约在任何显著的方面影响FDI的活动.3.3机构

机构的质量有可能是影响FDI活动的一个重要的决定因素，特别是对于由于各种原因而较不发达的国家。首先对资产欠缺法律保护增加了企业进行投资的资产不太可能征收的机会。机构质量差需要运作良好的市场（和/或贪污），这就增加了做生意的成本，也就减少了FDI的活动。最后，在一定程度上机构质量差导致基础设施差（即公共产品），当FDI确实进入市场则预计盈利能力会下降。

尽管这些基本假设是无争议的，但估计机构对外国直接投资的影响幅度是困难的，因为没有任何准确的机构测量。大部分措施是一个国家的政治，法律和一些经济体制的复合指数，根据官员或熟悉国家机制的商人的调查结果制定。由于受访者来自不同的国家导致国家间的可比性值得商榷。另外，机构通常会保持长久，因此随着时间的推移在一个国家内很少会发生有意义的变化。

由于这些原因，尽管跨国FDI研究通常包括机构以及或者贪污腐败的措施，但并不经常把它作为分析的重点。魏的论文（2000年;2000B）是一个例外，表明各种腐败指数与FDI有着强烈的负相关性，但其他的研究中没有发现这样的证据（如惠勒和么，1992年）。海因斯（1995）提供了一个有趣的“自然实验”的方法，通过研究1977年的美国反海外腐败法中关于处罚美国跨国公司贿赂外国官员的规定。他估计在法案实行的之后一段时间后会发现该法案对FDI的负面效应。这种自然实验分析为将来提出更令人信服的证据带来了希望，尽管发现这样的天然实验是非常困难的。3.4 贸易保护

外国直接投资和贸易保护之间的假设联系被大多数贸易经济学家看作是还算明朗的。即高贸易保护应该让企业更有可能替代子公司生产出口以避免贸易生产成本。这通常被称为关税跳跃投资。也许是因为这个理论相当简单而且寻常，一般情况下很少有研究专门检验这一假设。另一个可能的原因是数据驱动。在各行业间一致的非关税保护形式很难进行量化。许多企业层面的研究采用产业级别的措施来控制各种贸易保护方案，但往往结果好坏参半，其中包括Grubert和Mutti（1991），科格特和张（1996），和Blonigen（1997）。一种替代产业阶层措施是通过反倾销给企业提供特定的相当大的反倾销税来实现的。公司面临着要使用更加精确的措施来应对法律保护，Belderbos（1997）和Blonigen（2002）均发现关税跳跃FDI更有力的证据，尽管Blonigen的分析结果强烈暗示出这种反应只有总部设在发达国家的跨国公司才能看到。这可能是关税跳跃贸易保护与其他措施混合的另一个原因，外商直接投资需要大量的费用，很多小出口企业可能无法融资或寻找有利可图的方面。事实上，贸易保护可以明确地针对FDI较少的进口来源地。这表明外国直接投资和贸易保护可能是内源性的，关于这一问题几乎没有被实证过。有一个例外是Blonigen和FIGLIO（1998年），他们发现的证据表明，增加外国直接投资进入美国参议员的州或美国众议院的地区，会增加他们把票投给进一步的贸易保护的可能性。3.5 贸易效应

先前讨论到这一点的局部均衡研究在很大程度上忽略了外商直接投资的贸易影响，而这与潜在的FDI 的变化拉动力有着密切的联系。可能最常引用FDI的动机是作为出口到东道国家的替代品。由于巴克利和卡森（1981）的模型所呈现出的，可以认为出口是固定成本较低，但运输和贸易壁垒可变成本较高。与子公司服务于同一市场引入FDI允许大幅降低这些可变成本，但可能涉及更高的大于出口成本的固定成本。这表明了一个自然发展规律，一旦国外市场对跨国公司的产品需求达到足够大的规模，那么将会从出口发展到FDI。

在早期的论文中利普西和Weiss（1981;1984）对美国对东道国的FDI 以及出口进行回归分析，发现了一个正相关性，这违背了FDI替代出口的原理。然而，这些论文忽略了东道国市场这个变量的内生性，这一变量可以将跨国公司引进FDI以及出口产品的意愿朝着相同的方向增加或者减少。Grubert和Mutti（1991）根据出口销售，使用了利普西和Weiss（1981）类似的数据得到了负相关的回归结果，尽管结果在统计学上是不显著的。

Blonigen（2001）认为，问题在于贸易流量，要么是用最终产品替代了跨国公司的分支机构在同一国家生产产品，要么是将生产最终产品所使用的中间产品作为流量统计。前一种情况导致“贸易”和“外国直接投资”之间的负相关关系，而后者显示两者之间的正相关关系。Blonigen使用日本出口美国的10位制的关税协调制度下产品级别的贸易和FDI数据，结果显示日本对美国的FDI增加引起日本生产这些产品的中间产品的出口也增加了，但是最终产品的出口却下降了。赫德和里斯（2001）和斯文森（2004）分别使用日本企业层面的数据以及美国行业层面的数据提出了类似的证据。

上述讨论中一个潜在的问题是企业之间的关系（如投入到分销商的供应商），有可能影响FDI决策。日本企业往往在供应商和分销商间有更正式和公开的连接，所谓纵向联系财阀。赫德，里斯和斯文森（1995）探讨了是否其他日本企业在美国的一个州或邻近州的选址会通过企业相似的纵向联系财阀影响随后日本跨国公司的FDI。他们发现确实是这样，特别对于汽车部门来说，并且把这个作为有正式的供应商-经销商关系的企业之间产生了聚集经济的证据。

其他研究考虑了横向联系财阀对日本FDI的影响。横向联系财阀是在许多行业间企业集团的分组，但中心是围绕日本大型银行。这样的活动对FDI的三大潜在影响已经被提出。主要的潜在影响是利用横向联系财阀的银行作为低成本集资的来源，这将增加公司的整体投资，包括对外投资。正如霍什、卡什亚普和Scharfstein（1991）提到的，有一个财阀银行成员这样的关系可以降低监督成本，降低资金成本。他们对日本制造业企业进行分析发现的证据表明，比起其他企业这些横向联系财阀的公司在投资活动中比较少受限。随后的研究中检测了是否横向联系财阀增加了日本企业的对外直接投资，但往往结果很不显著或敏感（例如，见Belderbos和Sleugwaegen，1996）。

Blonigen，埃利斯和福斯滕（2005年）注意到了横向联系财阀的另一个可能的影响俄林模型的精确检验公式的形成遭遇了巨大的障碍，当有多于两个国家和地区的两个以上的生产要素时该模型预测贸易流量则可能有较大的不确定性。

第二篇：英文翻译

Introduction: with the rapid development of the economy, China ‘smprehensive national power has been improved effectively.As a saying said;“Want to become rich first road”.So China has begun to build the high-speed rail since years ago.The building of the high~speed rail is suited to China's national conditions and help our country to run well in the strong competition of the world.大多数经济学家认为：交通基础设施的供应水平和能力必须适度超前，否则就会影响社会经济持续、稳定 和健康发展。这就意味着要加大对交通基础设施的投资，但是政府在加大交通基础设施投资力度的同时，用于改善民生的措施实际却在相对地减少。从中国目前的经济发展和人民的收入状况来说，我认为中国高 铁弊大于利.Most economists believe that: the supply and capability of transportation infrastructure must advance appropriately, otherwise it will affect the sustainable, stable and healthy development of social economy.This means that we have to increase the investment into transportation infrastructure,But while government increase the investment into transportation infrastructure, it will to some extent decrease the practical measures to improve people's livelihood.From China's current situation, I think it will do more harm than good to build high-speed railway in China.Piont1: Building too fast go against the laws of economic development, causing many problems, such as loan repayment, staff placement.And high-speed railway construction needs large investment, from the use of the actual situation, the possibility of short-term cost recovery do not, there is also the problem of capital wasting.建设速度过快，容易违背经济发展规律,同时面对的问题较多，例如贷款偿还，员工安置等。中国第一条高 铁客运专线——从北京到天津，它在 2008 年 8 月通车后一年就亏损了 7 个亿。武广高铁总投资约 1166 亿元，目前的线路至少能开 120 对车，但实际上只开了 33 对，而且还坐不满，这是资本的严重浪费。所 以说高铁建设不仅需要大笔的投资，而且从运用的实际的情况来看，短期收回成本的可能性根本就没有。The fast building speed will violate the rule of economic development, and at same time it faced many problems, such as loan repayment, staff placement.First high-speed railway of China-from Beijing to Tianjin, it was launched in August 2008, after one year it lossed 70 millions.The total investment of

Wuhan-Guangzhou high-speed rail was about 110 billions yuan, now it is able to drive at least 120 pairs of cars, but in fact only 33 to drive, and lots of seats are empty, this is a serious waste of capital.The high-speed railway not only requires large construction investment, but also, it is impossible to recovery the short-term cost based on its actural implement.Poiimnt2: The building of the high spee

d rail can drive the development of the industry related.for example, the building need many workers and the new technology, so it expand the employment and promiot the technological innovation.In another word through the building, more steel products are needed.Another important hand is transport during the Spring Festival.During this period of time, large numbers of people going home together.So the high speed rail can relieve the transportation pressure ectively 高铁的票价较高，例如京津高铁，它行驶 30 分钟，却要 69 元票价，让人望而生叹啊。中国的 GDP 总量 高居世界第二，但人均 GDP 在世界的排名却还在百名开外，穷人还是绝大多数。武广高铁开通后，原有 的一些客运列车停运，意味着中低收入者将被迫选择高铁，接受高票价。这种行为伤及了底层人民的最根 本利 e 而且建设过程中容易出现贪污腐败问题。The fare of high Speed Rail is higher, for example, the Beijing-Tianjin high-speed rail, it costs 69 yuan for only drive 30minuts.China's GDP ranks the second in the world, but per capita GDP still ranks out of hundreds in the world, the poor is the majority.When Wuhan-Guangzhou high-speed railway was used, the original passenger trains were stopped, which means low-incomer will be forced to choose high-speed rail and accept the high fares.This action has

impair interests of the low class people, and the corruption problem will be prone to easily during the process of building.新建高铁实际是在现有几种交通方式的基础上新增一种交通方式。建成之后会与高速公路、现有铁路、飞 机、船运形成竞争关系，在原有运力并不紧张的背景下必然形成运力过剩。新建的高铁主要是客运专线，因此高铁并不会加快货物与资金的周转速度，不会降低全社会运行成本。要修建如此庞大的高速铁路网，必将消耗大量的资金，必将挤占人们收入上涨的空间与企业利润空间（加重税负）如果将此财政投入医疗、。社保、教育、技术研究，则会消除人们存钱的预防养老动机从而扩大消费，利于中国经济可持续发展。综 上所述，在中国大规模修建高铁对中国经济的长远发展来讲是弊大于利，不利于扩大内需、不利于产业结 构调整 结论：The high-speed railway will compete with the existing highway, railway, aircraft, shipping after it consummation which will lead to a situation capacity.The new high-speed railway is mainly to carry passenger, so it will not speed up the turnover rate between cargos and the capital and will not decrease the costs of the whole social transportation.To build such a large network of high-speed rail will need a large amount of money, the government must increase the taxes of people and enterprise to raise the capital.If this financial investment used in health care, social security, education, tec

第三篇：英文翻译

Overview of the Global System for Mobile Communications 1 History of GSM During the early 1980s, analog cellular telephone systems were experiencing rapid growth in Europe, particularly in Scandinavia and the United Kingdom, but also in France and Germany.Each country developed its own system, which was incompatible with everyone else’s in equipment and operation.This was an

undesirable situation, because not only was the mobile equipment limited to operation within national boundaries, which in a unified Europe were increasingly unimportant, but there was also a very limited market for each type of equipment, so economies of scale and the subsequent savings could not be realized.The Europeans realized this early on, and in 1982 the Conference of European s Posts and Telegraphs(CEPT)formed a study group called the Group Special Mobile(GSM)to study and develop a pan-European public land mobile system.The proposed system has to meet certain criteria: ·Good subjective speech quality ·Low terminal and service cost ·Support for international roaming ·Ability to support handheld terminals ·Support for range of new services and facilities ·Spectral efficiency ·ISDN compatibility In 1989, GSM responsibility was transferred to the European Telecommunication Standards Institute(ETSI), and phase I of the GSM specifications were published in 1990.Commercial service was started in mid-1991, and by 1993 there were 36 GSM networks in 22 countries.Although standardized in Europe, GSM is not only a European standard.Over 200 GSM networks are operational in 110 countries around the world.In the beginning of 1994, there were 1.3 million subscribers worldwide, which had grown to more than 55 million by October 1997.With North America making a delayed entry into the GSM field with a derivative of GSM called PCS1900, GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for Mobile communications.The developers of GSM chose an unproven(at the time)digital system, as opposed to the then-standard analog cellular systems like AMPS in the United States and TACS in the United Kingdom.They had faith that advancements in compression algorithms and digital signal processors would allow the fulfillment of the original criteria and the continual improvement of the system in terms of quality and cost.The over 8,000 pages of GSM recommendations try to allow flexibility and competitive innovation among suppliers, but provide enough standardization to guarantee proper interworking between the components of the system.This done by providing functional and interface descriptions for each of the functional entities defined in the system.2 General Concepts 2.1 Analog Versus Digital Telephony Systems First-generation systems were analog.During the early 1980s these underwent rapid development in Europe.Although the NMT system was used by all the Nordic countries, and the TACS system in the United Kingdom and Italy, there was a variety of systems and no compatibility among them.Compared with these systems, the main advantages offered by GSM, which is the most important of the second-generation digital systems, are: ·Standardization;·Capacity;·Quality;·Security.Standardization guarantees compatibility among systems of different countries, allowing subscribers to use their own terminals in those countries that have adopted the digital standard.The lack of standardization in the first-generation system limited service to within the borders of a country.Mobility is improved, since roaming is no longer limited to areas covered by a certain system.Calls can be charged and handled using the same personal number even when the subscriber moves from one country to another.Standardization also allows the operator to buy entities of the network from different vendors, since the functional elements of the network and the interfaces between these elements are standardized.This means that a mobile phone from any manufacturer is able to communicate with any network, even if this network is built with entities from different vendors.This leads to a large economy of scale and results in cost reduction for both the operator and the subscriber.Furthermore, the phone cost is also reduced, because GSM is an international standard, produced quantities are greater and the level of competition is high.With respect to capacity, the use of the radio resource is much more efficient in a digital system such as GSM than in an analog system.This means that more users can be allocated in the same frequency bandwidth.This is possible with the use of advanced digital techniques, such as voice compression algorithms, channel coding, and multiple access techniques.Note that capacity gains are also achieved with radio frequency reuse, which had also used in analog systems.Frequency reuse means that a given carrier can be employed in different areas.The quality in digital transmission systems is better, thanks to the channel coding schemes that increase the robustness in the face of noise and disturbances such as interference caused by other users or other systems.The quality improvement is also due to the improved control of the radio link, and adaptations to propagation conditions, with advanced techniques such as power control or frequency hopping.This will be explained in greater detail in the next section.In terms of security, powerful authentication and encryption techniques for voice and data communications are enabled with GSM, which guarantees protected access to the network, and confidentiality.2.2 Cellular Telephony In mobile radio systems, one of the most important factors is the frequency spectrum.In order to make the best use of the bandwidth, the system is designed by means of the division of the service area into neighboring zones, or cells, which in theory have a hexagonal shape.Each cell has a Base Transceiver Station(BTS), which to avoid interference operates on a set of radio channels different from those of the adjacent cells.This division allows for the use of the same frequencies in nonadjacent cells.A group of cells that as a whole use the entire radio spectrum available to the operator is referred to as a cluster.The shape of a cell is irregular, depending on the availability of a spot for the BTS, the geography of the terrain, the propagation of the radio signal in the presence of obstacles, and so on.In dense urban areas, for instance, where the mobile telephony traffic is important, the diameter of the cells is often reduced in order to increase capacity.This is allowed since the same frequency channels are used in a smaller area.On the other hand, reducing the cell diameter leads to a decrease in the distance necessary to reuse the frequencies(that is, the distance between two co-channel cells), increasing co-channel interference.In order to minimize the level of interference, several techniques are used on the radio interface.A basic example of cluster organization is shown in Figure 1.In this example, we see a reuse attern for seven different frequencies, f1 to f7.These frequencies correspond to the beacon carrier of each cell, on which signaling information about the cell is broadcast(see Section 2.7).It can be seen from this figure that a given carrier can be reused in two separate geographical areas, as long as these areas are far enough from each other to reduce the effect of interference.With this technique of dividing the area in cells and clusters, the operator can increase the area it is able to cover with a limited frequency bandwidth.Figure 1 Example of a Cell Planning

在80 年代初期期间，模式手机系统在欧洲体验迅速增长，特别在斯堪的那

维亚和英国，以及法国和德国。每个国家开发了它自己的系统，在设备和操作 上是互不相容的。这是一个不受欢迎的情况，因为不仅移动通信设备被限制在国 界之内，这在统一的欧洲是越来越不重要的，而且每种类型的设备都只有一个非 常有限的市场，因此经济尺度及随后的储蓄不可能体会。

欧洲人早就意识到了这点，并且在1982 年欧洲邮电管理联合会(CEPT)上形 成了移动通信特别研究组(GSM)来研发一个能在全欧洲大陆通用的移动通信系 统。提出的系统必须符合以下标准： 〃通话质量好

〃终端及服务费用低 〃支持国际漫游

〃能够支持可随身携带的终端 〃支持一系列新的服务和设备 〃效率高

〃与ISDN 兼容

1989 年，GSM 的责任转移了到欧洲电信标准学院(ETSI)，并且GSM 规格的

第一阶段也在1990 年出版了。商业服务在1991 年中期开始了，截至1993 年有 36 个GSM 网络在22 个国家诞生了。GSM 不仅仅是欧洲标准，尽管它是在欧洲 规范化的。现已有200 多个GSM 网络在全球110 个国家和地区运行。1994 年初 期全球有1,300,000 用户，截至1997 年10 月已突破55,000,000 用户。随着美国

后来在GSM 领域制造了一个词条PCS1900 作为GSM 的拓展,GSM 系统已发展至 各大洲,并且缩写词GSM 现在已可以代表移动通信的全局系统。

GSM 开发商选择了一个当时未经证明的数字系统，与后来的标准模式蜂窝系 统相对，就象美国叫AMPS，而英国叫TACS 一样。他们坚信能够推进压缩算法 和数字信号处理器使其能够根据质量和费用将原始标准和系统连续改善。GSM 推荐8,000 页设法使得在与供应商竞争之中体现灵活性和创新，但提供 足够的标准来保证在系统的组分之间适当配合工作。完成提供功能和接口描述的 功能个体在系统中都有定义。

第一代系统是模拟的。上个世纪80 年代初期在欧洲迅速发展。虽然所有北 欧国家使用TACS 系统，英国和意大利使用NMT 系统，它们之间还有各式各样 的系统不兼容。和这些系统相比，GSM 提供的更重要的第二代数字系统主要优势 体现在： 〃标准化； 〃容量； 〃质量； 〃安全。

标准化保证了不同国家系统之间的兼容性，允许采取了数字化标准的国家的 订户使用他们自己的终端。在第一代系统中缺乏标准化的有限服务为在国家的边 界之内。流动性被改进，漫游不再被限制到某一系统包括的面积之内。既使当用 户从一个国家移动到另一个国家，电话也可以使用同一个个人号码。因为网络的功能元件和这些元素之间的接口被规范化，操作员可以从不同的 供营商购买。这意味着所有制造商的移动电话能与任何网络沟通，即使这个网络 是由不同的供营商的功能元件建立的。这为操作员和订户带来费用成本的降低。此外，电话费用也降低了，因为GSM 是国际标准，生产数量大，竞争水平高。能力方面，数字系统如GSM 比模拟系统使用的无线资源更有效。这意味着 更多的用户可以使用同一频带。这就有可能利用先进的数字技术，如语音压缩算 法，信道编码和多址接入技术。请注意，无线电频率复用也取得了一定增益，这 也已用于模拟系统。频率复用意味着同一载波可以在不同的地区重复使用。由于这种信道编码方案，提高了可靠性及对噪音和其他用户或系统的干扰能 力，数字传输系统的质量更好了。质量改进的原因还在于改善了对无线连接的控 制，并适应传播条件下，使用先进的技术，如电源控制或跳频。质量改进的原因 还在于使用先进的技术如电源控制或跳频改善了无线连接的控制,，传播条件的适

应性等。这些将在下文中做更详尽的解释。

在安全方面，GSM 具有语音和数据通信的强大的认证和加密技术的功能，保 证了保护接入网络和保密性。

在移动通信系统中，一个最重要的因素就是频谱。为了最有效地利用带宽，系统设计的目的是通过基站的服务区到周边小区，理论上是一个正六边形。每个 小区有一个收发基站（BTS），其中，以避免相邻小区的不同无线信道在运行时 产生相互干扰。这样可以在不相邻的小区使用同一载频。一组小区，作为一个整 体，给运营商提供整个无线电频谱是指一个区群。小区的形状是不规则的，这取 决于是否有现成的基站，地理地形，无线电信号传播中存在的障碍，等等。例如，在人口密集的城市地区，移动电话的通行非常重要，小区的直径往往 会减小，以提高其通行能力。

这是允许的，因为同一频道只在一个较小的地区内使用。另一方面，小区直 径的减小导致使用同一频率的小区间的距离（即两个公共通道小区间的距离）缩 小了，增强了各频道之间的相互干扰。为了尽量提高抗干扰的能力，无线接口使 用了一系列技术。

一个基本的区群组织的结构如图1 所示。在这个例子中，我们看到了一个复 用模式的7 个不同的频率，f1 至f7。这些频率对应于每个小区的信标载波，整个

小区的信号信息就靠它们被传播出去（见第2.7 节）。从图中可以看出，某一载 波可在两个不同的地理区域重复使用，只要这两个地区离的足够远，相互之间的 干扰足够小。这一技术把地区分成小区和区群，经营者可以利用有限的带宽增加 覆盖区域的面积。

第四篇：英文翻译

School Profile

Jin Yuan Primary School was founded in 1966，and now it has 40 years‟ history.Thepredecessor of the school is ShiMian kuang Children Shool.In May 1993 ,It was placed under the Dalian Development Zone.In 2002, the new building was reconstruction in the school site.Now it occupies a total area of 18500 square meters, with a total construction area of 9020 square meters, it has got 30 class and 1478 students.Our school always adhere to the school mission-“To lay the foundation for the development of student life” and school

philosophy “To train the younger generation for adapting to the new society”.with “implementing quality education, making our school into modernization, distinctive characteristics, high-grade The 'people satisfaction' schools ”for the school mission and goals.Focusing on behavior, raising habits, pursuingdevelopment, hing research,benefit, the high quality;grasping

characteristics, treeing famous“ as the school ideas.”Innovation in operating a school, Distinctive Features,“ as the school way.Our school has been named the standardization of school facilities,education and management of Dalian advanced group, Green School of Dalian , big break in Dalianadvanced unit for physical education curriculum standard education health system,development zone course reform summary advanced unit, the characteristics of the development of school-based curriculum development awards such as prizes, Excellence Award and many other honors.In addition, teaching and research training center was also named the Development of information technology, sports, music, experimental point of school mental health disciplines.School emphasis on ”Science Education“, it has been named the Science and technology activities advanced units;land-sea model training base in Liaoning Province;Dalian Science and Technology Advanced Unit;advanced science and technology activities in Dalian youth units;The intelligent robot teaching activities carried out to further broaden the field of science teaching in recent years, we got soccer robot competition and the Youth Science and Technology Invention Contest winners many times in national, provincial and municipal.Our school was known by scientific and technological innovations, it has become a golden source of education and school characteristics of primary brand, and its fruitful results of educating people to win recognition of the higher education sector and social praise.Our school actively promoting international exchanges and cooperation.Based on the national culture, the students involved in multicultural perspective, let the student to have the ability to

communicate with different culture and cultural understanding

ability, feeling the other civilizations, inheriting Chinese culture, and for students build facing the world, developing yourself and

development of China's platform.At present,we have established the friendly and cooperative relations with Singapore, Britain and other countries of the schools.Our school is committed to the construction of educational information, establishing the educational information to promote the development strategy of modernization of school education.We was honored with the first model school education information by Dalian Municipal Bureau of Education.Physical education in our schoolis also flourished, we always adhere to the ”Sunshine Sports“ project.To ensure that every student at least one hour of exercise a day, each have a favorite sport, the school was named the physical education curriculum standards of Dalian advanced unit, DalianBig calisthenics demonstration school, Dalian”campus football

project“ Development of school.In recent years,school „s sports teams in all kinds of various game had good performance , and it becomes the school‟sbeautifulcard.Standing at a new starting point, facing the new century, we will try to”build multicultural education, reveal personality, improve

the educational grade, promote the connotation development" as our target, makes determined efforts, scientific planning, and strive to improve the level and constantly expand its reputation, trying to be the children paradise of JinYuan Primary School.

第五篇：英文翻译

whether the university student should pay more atteion on studying or not ?the answer issure.First of all,during these time,we can touch more things,whichwehave not ever meet before and make a graetinflunce on our future life,If we don't handle it well,maybe we will lose a lot of thingswe adapt to sociaty more easily and more diffcult.we have time to play, but when you are playing and relaxing, dont forget the things you must do at school.school life is on of the best sections of your life.you need school life and time to learn and do things.