外文翻译

The smart gridSmart grid is the grid intelligent (electric power), also known as the "grid" 2.0, it is based on the integration, high-speed bidirectional communication network, on the basis of through the use of advanced sensor and measuring technology, advanced equipme nt technology, the advancedcontrol method, and the application of advanced technology of decision support system, realize the power grid reliability, security, economic, efficient, environmental friendly and use the security target, its main features include self-healing, incentives and include user, against attacks, provide meet user requirements of power quality in the 21st century, allow all sorts of different power generation in the form of access, start the electric power market and asset optimizatio n run efficiently.The U.S. department of energy (doe) "the Grid of 2030" : a fully automated power transmission network, able to monitor and control each user and power Grid nodes, guarantee from power plants to end users among all the nodes in the whole process of transmission and distribution of information and energy bi-directional flow.China iot alliance between colleges: smart grid is made up of many parts, can be divided into:intelligent substation, intelligent power distribution network, intelli gent watt-hourmeter,intelligent interactive terminals, intelligent scheduling, smart appliances, intelligent building electricity, smart city power grid, smart power generation system, the new type of energy storage system.Now a part of it to do a simple i ntroduction. European technology BBS: an integration of all users connected to the power grid all the behavior of the power transmission network, to provide sustained and effective economic and security of power.Chinese academy of sciences, institute of electrical: smart grid is including all kinds of power generation equipment, power transmission and distribution network, power equipment and storage equipment, on the basis of the physical power grid will be modern advanced sensor measurement technology, network technology, communicationtechnology, computing technology, automationand intelligent control technology and physical grid highly integrated to form a new type of power grid, it can realize the observable (all the state of the equipment can monitor grid), can be controlled (able to control the power grid all the state of the equipment), fully automated (adaptive and self-healing) and system integrated optimization balance (power generation, transmission and distribution, and the optimization of the balance between electricity), so that the power system is more clean, efficient, safe and reliable.American electric power research institute: IntelliGrid is a composed of numerous automation system of power transmission and distribution power system, in a coordinated, effective and reliable way to achieve all of the power grid operation: have self-healing function;Rapid response to the electric power market and enterprise business requirements;Intelligent communication architecture, realizes the real-time, security, and flexible information flow, to provide users with reliable, economic power services. State grid electric power research institute, China: on the basis of the physical power grid (China's smart grid is based on high voltage network backbone network frame, different grid voltage level based on the coordinated development of strong power grid), the modern advanced sensor measurement technology, communication technology, information technology, computer technology and control technology and the physical power grid highly integrated to form a new type of power grid.It to fully meet user demand for electricity and optimize the allocation of resources, guarantee the safety, reliability and economy of power supply, meet environmental constraints, ens ure the quality of electric energy, to adapt to the development of power market, for the purpose of implementing the user reliable, economic, clean and interactive power supply and value-added services.BackgroundStrong smart grid development in the wor ld is still in its infancy, without a common precisely defined, its technology can be roughly divided into four areas: advanced Measurement system, advanced distribution operation, advanced transmission operation and advanced asset management.Advanced meas urement system main function is authorized to the user, make the system to establish a connection with load, enabling users to support the operationof the power grid;Advanced core distribution operation is an online real-time decision command, goal is to disaster prevention and control, realizing large cascading failure prevention;Advanced transmission operation main role is to emphasize congestion ma nagement and reduce the risk of the large-scale railway;Advanced asset management is installed in the system can provide the system parameters and equipments (assets) "health" condition of advanced sensor, and thereal-time information collected by integrat ion and resource management, modeling and simulation process, improve the operation and efficiency of power grid.The smart grid is an important application of Internet of things, and published in the journal of computer smart grid information system archit ecture research is carried on the detailed discussion on this, and the architecture of the smart grid information system are analyzed.The market shareThe establishment of the smart grid is a huge historical works.At present many complicated smart grid project is underway, but the gap is still great.For the provider of the smart grid technology, promote the development of facing the challenges of the distribution network system i s upgrading, automation and power distribution substation transportation, smart grid network and intelligent instruments.According to the latest report of parker investigators, smart grid technology market will increase from $2012 in 33 billion to $2020 in 73 billion, eight years, the market accumulated up to $494 billion.China smart grid industry market foresight and investment forward-looking strategic planning analysis, points out that in our country will be built during the "twelfth five-year""three vertical and three horizontal and one ring" of uhv ac lines, and 11 back to u hv dc transmission project construction, investment of 300 billion yuan.Although during the period of "much starker choices-and graver consequences-in" investment slowed slightly, the investment is 250 billion yuan.By 2015, a wide range of national power grid, long distance transmission capacity will reach 250 million kilowatts, power transmission of 1.15 trillion KWH per year, to support the new 145 million kilowatts of clean energy generation given and sent out, can satisfy the demand of morethan 1 million electric cars, a grid resource configuration optimization ability, economic efficiency, safety and intelligent levels will be fully promoted.The abroad application of analysisIn terms of power grid development foundation, national electricity dema nd tends to be saturated, the grid after years of rapid development, architecture tends to be stable, mature, have a more abundant supply of electric power transmission and distribution capacity.Germany has "E - Energy plan, a total investment of 140 million euros, from 2009 to 2012, four years, six sites across the country to the smart grid demonstration experiment.At the same time also for wind power and electric car empirical experiments, testing and management of power consumption of the Internet.Big companies such as Germany's Siemens, SAP and Swiss ABB are involved in this plan.To smart grid Siemens 2014 annual market scale will reach 30 billion euros, and plans to take a 20% market share, make sure order for 6 billion euros a year.The advanced nat ureCompared with the existing grid, smart grid, reflects the power flow, information flow and business flow marked characteristics of highly integration, its advancement and advantage mainly displays in:(1) has a strong foundation of grid system and te chnical support system, able to withstand all kinds of external disturbance and attacks, can adapt to large-scale clean energy and renewable energy access, strong sex of grid reinforced and ascend.(2) the information technology, sensor technology, automatic control technology organic combination with power grid infrastructure, a panoramic view of available power grid information, timely detection, foresee the possibility of failure.Fault occurs, the grid can be quickly isolate fault,realize self recovery,to avoid the occurrence of blackouts.(3) flexible ac/dc transmission, mesh factory coordination, intelligent scheduling, power storage, and distribution automation technology widespread application, makes the control of power grid operation more flexibl e,economic, and can adapt to a large number of distributed power supply, power grid and electric vehicle charging and discharging facility access.(4) communication, information, and the integrated use of modern management technology, will greatly improve the efficiency of power equipment, and reduce the loss of electrical power, making the operation of power grid is more economic and efficient.(5) the height of the real-time and non real-time information integration, sharing and utilization, to run the show management comprehensive, complete and fine grid operation state diagram, at the same time can provide decision support, control scheme and the corresponding response plans.(6) to establish a two-way interactive service mode, users can real-time understand the status of the power supply ability, power quality, price and power outage information, reasonable arrangement of electric equipment use;The electric power enterprise can obtain the user's electricity information in detail, to provide more value-added services.developmentaltrend"Twelfth five-year" period, the state grid will invest 500 billion yuan to build the connection of large ene rgy base and center of the "three horizontal three longitudinal" main load of ultra high voltage backbone network frame and 13 back to long branch, engineering, to form the core of the world first-class strong smart grid."Strong smart grid technology standards promulgated by the state grid system planning", has been clear about the strong smart grid technology standards roadmap, is the world's first used to guide the development of smart grid technology guiding standards.SGC planning is to built 2015 basic information, automation, interaction characteristics of strong smart grid, formed in north China, central China, east China, for the end to the northwest and northeast power grid for sending the three synchronous power grid, the grid resource allocati on ability, economic efficiency and safety level, technology level and improve intelligent level.(1) the smart grid is the inevitable developing trend ofpower grid technology.Such as communication, computer, automation technology has extensive applicati on in the power grid, and organic combination with traditional electric power technology, and greatly improve the intelligent level of the power grid.Sensor technology and information technology application in the power grid, the system state analysis and auxiliary decision provides the technical support, make it possible to grid self-healing.Scheduling technology, automation technology and the mature development of flexible transmission technology, for the development and utilization of renewable energy an d distributed power supply provides the basic guarantee.The improvement of the communication network and the popularization and application of user information collection technology, promote the two-way interaction with users of the grid.With the further development of various new technologies, application and highly integrated with the physical power grid, smart grid arises at the historic moment.(2) the development of smart grid is the inevitable choice of social and economic development.In order to ach ieve the development of clean energy, transport and given power grid must increase its flexibility and compatibility.To withstand the increasingly frequent natural disasters and interference, intelligent power grid must rely on means to improve its securit y defense andself-healing ability.In order to reduce operating costs, promote energy conservation and emissions reduction, power grid operation must be more economic and efficient, at the same time must to intelligent control of electric equipment, reduce electricity consumption as much as possible.Distributed generation and energy storage technology and the rapid development of electric cars, has changed the traditional mode of power supply, led power flow, information flow, business flow constantly fusion, in order to satisfy the demands of increasingly diverse users.PlanJapan plans to all the popularity of smart grid in 2030, officer of the people at the same time to promote the construction of overseas integrated smart grid.In the field of battery, Japanese firms' global market share goal is to strive to reach 50%, with about 10 trillion yen in the market.Japan's trade ministry has set up a "about the next generation of energy systems international standardizationresearch institute", the japan-american established in Okinawa and Hawaii for smart grid experimental project [6].Learns in the itu, in 2020 China will be built in high power grid with north China, east China, China as the center, northeast, northwest 750 kv uhv power grid as the sending, connecting each big coal base, large hydropower bases, big base for nuclear power, renewable energy base, the coordinated development of various grid strong smart grid.In north China, east China, China high voltage synchronous ZhuWangJia six "five longitudi nal and transverse" grid formation.The direction ofIn the green energy saving consciousness, driven by the smart grid to become the world's countries to develop a focus areas.The smart grid is the electric power network, is a self-healing, let consum ers to actively participate in, can recover from attacks and natural disasters in time, to accommodate all power generation and energy storage, can accept the new product, service and market, optimize asset utilization and operation efficiency, provide qua lity of power supply for digital economy.Smart grid based on integrated, high-speed bidirectional communication network foundation, aims to use advanced sensor and measuring technology, advanced equipment, technology and advanced control methods, and adv anced technology of decision support system, realize the power grid reliability, security, economic, efficient, environmental friendly, and the use of safe run efficiently.Its development is a gradual progressive evolution, is a radical change, is the product of the coordinated development of new and existing technologies, in ad dition to the network and smart meters also included the wider range.Grid construction in high voltage network backbone network frame, all levels of the coordinated development, informatization, automation, interaction into the characteristics of strong smart grid, improve network security, economy, adaptability and interactivity, strength is the foundation, intelligence is the key.meaningIts significance is embodied in the foll owing aspects:(1) has the strong ability of resources optimization allocation.After the completion of the smart grid in China, will implement the big water and electricity, coal, nuclear power, large-scale renewable energy across regions, long distance, large capacity, low loss, high efficiency, regional power exchange capacity improved significantly.(2) have a higher level of safe and stable operation.Grid stability and power supply reliability will be improved, the safety of the power grid close coord ination between all levels of line, have theability to against sudden events and serious fault, can effectively avoid the happening of a wide range of chain failure, improve power supply reliability, reduce the power loss.(3) to adapt and promote the dev elopment of clean energy.Grid will have wind turbines power prediction and dynamic modeling, low voltage across, and active reactive power control and regular units quickly adjust control mechanism, combined with the application of large capacity storage technology, the operation control of the clean energy interconnection capacity will significantly increased, and make clean energy the more economical, efficient and reliable way of energy supply.(4)implementing highly intelligent power grid scheduling.Co mpleted vertical integration, horizontal well versed in the smart grid scheduling technology support system, realize the grid online intelligent analysis, early warning and decision-making, and all kinds of new transmission technology and equipment of effi cient control and lean control of ac/dc hybrid power grid.(5)can satisfy the demands of electric cars and other new type electric power user services.Would be a perfect electric vehicle charging and discharging supporting infrastructure network, can meet the needs of the development of the electric car industry, to meet the needs of users, realize high interaction of electric vehicles and power grid.(6) realize high utilization and whole grid assets life cycle management.Can realize electric grid system of the whole life cycle management plan.Through smart grid scheduling and demand side management, power grid assets utilization hours, power grid assets efficiency improvedsignificantly.(7) to realize power convenient interaction between the user and the grid.Will form a smart electricity interactive platform, improving the demand side management, to provide users with high-quality electric power service.At the same time, the comprehensive utilization of the grid can be distributed power supply, intelli gent watt-hour meter, time-sharing electricity price policy and the electric vehicle charging and discharging mechanism, effectively balance electric load, reduce the peak valley load difference, reduce the power grid and power construction costs.(8)grid management informatization and the lean.Covering power grid will each link of communication network system, realize the power grid operation maintenance integrated regulation, data management, information grid spatial information services, and production and scheduling application integration, and other functions, to realize all-sided management informatization and the lean.(9) grid infrastructure of value-added service potential into full play.In power at the same time, the national strategy of "triple play" of services, to provide users with community advertising, network television, voice and other integrated services, such as water supply, heating, gas industry informatization, interactive platform support, expand the range of value-added services and improve the grid infrastructure and capacity, vigorously promote the development of smart city.(10)Gridto promote the rapid development of related industries.Electric power industry belongsto the capital-intensive and technology-intensive industry, has the characteristics of huge investment, long industrial chain.Construction of smart grid, which is beneficial to promote equipment manufacturing information and communication industry technology upgrade, for our country to occupy the high ground to lay the foundation in the field of electric power equipment manufacturing.Important significanceLife is convenientThe construction of strong smart grid, will promote the development of intelligent community, smart city, improve people's quality of life.(1) to make life more convenient.Home intelligent power system can not onlyrealize the real-time control of intelligent home appliances such as air conditioning, water heater and remote control;And can provide telecommunication network, Internet, radio and television network access services;Through intelligent watt-hour meter will also be able to achieve au tomatic meter reading and automatic transfer fee, and other functions.(2) to make life more low carbon.Smart grid can access to the small family unit such as wind power and photovoltaic roof, pushing forward the large-scale application of electric cars, so as to raise the proportion of clean energy consumption, reduce the pollution of the city.(3) to make life more economical.The smart grid can promote power user role transformation, both electricity and sell electricity twofold properties;To build a family for the user electricity integrated services platform, to help users choose the way of electricity, save energy, reduce the energy expense.Produce benefitThe development of a strong smart grid, the grid function gradually extended to promote the optim al allocation of energy resources, guarantee the safe and stable operation of power system, providing multiple open power service, promote the development of strategic emerging industries, and many other aspects.As China's important energy delivery and configuration platform, strong and smart grid from the investment construction to the operation of production process will be for the national economic development, energy production and use, environmental protection bring great benefits.(1)in power system.Can save system effective capacity;Reducing the system total power generation fuel cost;Improving the efficiency of grid equipment, reduce construction investment;Ascension grid transmission efficiency, reduce the line loss.(2)in terms of power customers.Can realize the bidirectional interaction, to provide convenient services;Improving terminal energy efficiency, save power consumption;To improve power supply reliability, and improve power quality.(3) in the aspect of energy saving and environment.Can improve the efficiency of energy utilization, energy conservation and emissions reduction benefit.To promote clean energy development, realize the alternative reductionbenefits;Promote the overall utilization of land resources, saving land usage.(4) other aspects.Can promote the economic development, jobs;To ensure the safety of energy supply;Coal for power transmission and improve the efficiency of energy conversion, reducing the transportation pressure.Propulsion system(1) can effectively improve t he security of power system and power supply e of strong smart grid "self-healing" function, can accurately and quickly isolate the fault components, and in the case of less manual intervention make the system quickly returned to normal, so as to improve the security and reliability of power supply system.(2) the power grid to realize the sustainable development.Strong smart grid technology innovation can promote the power grid construction, implementation technology, equipment, operation an d management of all aspects of ascension, to adapt to the electric power market demand, promote the scientific and sustainable development of power grid.(3) reduce the effective ing the power load characteristics in different regions of the ch aracteristics of big differences through the unification of the intelligent dispatching, the peakand peak shaving, such as networking benefit;At the same time through the time-sharing electricity price mechanism, and guide customers low power, reduce the peak load, so as to reduce the effective capacity.(4) to reduce the system power generation fuel costs.Construction of strong smart grid, which can meet the intensive development of coal base, optimization of power distribution in our country, thereby red ucing fuel transportation cost;At the same time, by reducing the peak valley load difference, can improve the efficiency of thermal power unit, reduce the coal consumption, reduce the cost.(5)improve the utilization efficiency of grid equipment.First of all, by improving the power load curve, reduce the peak valley is poor, improve the utilization efficiency of grid equipment;Second, by self diagnosis, extend the life of the grid infrastructure.(6) reduce the line loss.On the important basis of uhv transmission technology of strong smart grid, will greatly reduce the loss rate in the electric power transmission;Intelligent scheduling system, flexible transmission technology and real-time two-way interaction with customers, can optimize the tide distribut ion, reducing line loss;At the same time, the construction and application of distributed power supply, also reduce the network loss of power transmission over a long distance.Allocation of resourcesEnergy resources and energy demand in the reverse distribution in our country, more than 80% of the coal, water power and wind power resource distribution in the west, north, and more than 75% of the energy demand is concentrated in the eastern and central regions.Energy resources and energy demand unbalance d distribution of basic national conditions, demand of energy needs to be implemented nationwide resource optimizing configuration.The construction of strong smart grid, for optimal allocation of energy resources provides a good platform.Strong smart grid is completed, will form a strong structure and sending by the end of the power grid power grid, power capacity significantly strengthened, and the formation of the intensity, stiffness of uhv power transmission network, realize the big water and electricit y, coal, nuclear power, large-scale renewable energy across regions, long distance, large capacity, low loss, high efficiency transport capacity significantly increased power a wide range of energy resources optimization.Energy developmentThe development and utilization of clean energy such as wind power and solar energy to produce electricity is given priority to, in the form of the construction of strong smart grid can significantly improve the grid's ability to access, given and adjust clean energy, vigorously promote the development of clean energy.(1) smart grid, the application of advanced control technology and energy storage technology, perfect the grid-connected clean energy technology standards, improve the clean energy acceptance ability.Clean energy base, (2) the smart grid, rational planning of large-scale space truss structure and sending the power structure, application of uhv, flexible transmission technology, meet the requirements of the large-scale clean energy electricitytransmission.(3) the smart grid for large-scale intermittent clean energy to carry on the reasonable and economic operation, improve the operation performance of clean energy production.(4) intelligent with electric equipment, can achieve acceptance and coordinated cont rol of distributed energy, realize the friendly interaction with the user, the user to enjoy the advantages of new energy power.Energy conservation and emissions reductionStrong smart grid construction to promote energy conservation and emissions reduc tion,development of low carbon economy is of great significance: (1) to support large-scale clean energy unit net, accelerate the development of clean energy, promote our country the optimization of energy structure adjustment;(2) to guide users reasonable arrangement of electricity, reducing peak load, stable thermal power unit output, reduce power generation coal consumption;(3) promote ultra-high voltage, flexible transmission, promotion and application of advanced technology such as economic operation, reduce the transmission loss, improve power grid operation efficiency;(4) to realize the power grid to interact with users effectively, promote intelligent power technology, improve the efficiency of electricity;(5) to promote the electric car of large-scale application, promote the development of low-carbon economy, achieve emission reduction benefits.There are three milestones of the concept of smart grid development:The first is 2006, the United States "smart grid" put forward by the IBM solution.IBM smart grid is mainly to solve, improve reliability and safety of power grid from its release in China, the construction of the smart grid operations management innovation - the new train of thought on the development of China's power "the white paper can be seen that the scheme provides a larger framework, through to the electric power production, transmission, the optimization of all aspects of retail management, for the relevant enterprises to improve operation efficiency and reliability, reduce cost dep icts a blueprint.IBM is a marketing strategy.The second is the energy plan put forward by the Obama took office, in addition to the published plan, the United States will also focus on cost $120 billion a year circuit。

Strengths优势All these private sector banks hold strong position on CRM part, they have professional, dedicated and well-trained employees.所以这些私人银行在客户管理部分都持支持态度，他们拥有专业的、细致的、训练有素的员工。

Private sector banks offer a wide range of banking and financial products and financial services to corporate and retail customers through a variety of delivery channels such as ATMs, Internet-banking, mobile-banking, etc. 私有银行通过许多传递通道（如自动取款机、网上银行、手机银行等）提供大范围的银行和金融产品、金融服务进行合作并向客户零售。

The area could be Investment management banking, life and non-life insurance, venture capital and asset management, retail loans such as home loans, personal loans, educational loans, car loans, consumer durable loans, credit cards, etc. 涉及的领域包括投资管理银行、生命和非生命保险、风险投资与资产管理、零售贷款（如家庭贷款、个人贷款、教育贷款、汽车贷款、耐用消费品贷款、信用卡等）。

Private sector banks focus on customization of products that are designed to meet the specific needs of customers. 私人银行主要致力于为一些特殊需求的客户进行设计和产品定制。

因为学校对毕业论文中的外文翻译并无规定，为统一起见,特做以下要求：1、每篇字数为1500字左右，共两篇；2、每篇由两部分组成:译文+原文.3 附件中是一篇范本，具体字号、字体已标注。

外文翻译（包含原文)(宋体四号加粗）外文翻译一（宋体四号加粗）作者：(宋体小四号加粗）Kim Mee Hyun Director, Policy Research & Development Team，Korean Film Council（小四号）出处：(宋体小四号加粗)Korean Cinema from Origins to Renaissance(P358～P340) 韩国电影的发展及前景（标题：宋体四号加粗）1996～现在数量上的增长(正文:宋体小四）在过去的十年间，韩国电影经历了难以置信的增长。

上个世纪60年代，韩国电影迅速崛起，然而很快便陷入停滞状态,直到90年代以后，韩国电影又重新进入繁盛时期。

在这个时期，韩国电影在数量上并没有大幅的增长，但多部电影的观影人数达到了上千万人次。

1996年，韩国本土电影的市场占有量只有23.1%。

但是到了1998年，市场占有量增长到35。

8%，到2001年更是达到了50%。

虽然从1996年开始，韩国电影一直处在不断上升的过程中，但是直到1999年姜帝圭导演的《生死谍变》的成功才诞生了韩国电影的又一个高峰。

虽然《生死谍变》创造了韩国电影史上的最高电影票房纪录，但是1999年以后最高票房纪录几乎每年都会被刷新。

当人们都在津津乐道所谓的“韩国大片”时，2000年朴赞郁导演的《共同警备区JSA》和2001年郭暻泽导演的《朋友》均成功刷新了韩国电影最高票房纪录.2003年康佑硕导演的《实尾岛》和2004年姜帝圭导演的又一部力作《太极旗飘扬》开创了观影人数上千万人次的时代。

姜帝圭和康佑硕导演在韩国电影票房史上扮演了十分重要的角色。

从1993年的《特警冤家》到2003年的《实尾岛》，康佑硕导演了多部成功的电影。

毕业论文外文翻译格式毕业论文外文翻译格式在撰写毕业论文时，外文翻译是一个重要的环节。

无论是引用外文文献还是翻译相关内容，都需要遵循一定的格式和规范。

本文将介绍一些常见的外文翻译格式，并探讨其重要性和应用。

首先，对于引用外文文献的格式，最常见的是使用APA（American Psychological Association）格式。

这种格式要求在引用外文文献时，先列出作者的姓氏和名字的首字母，然后是出版年份、文章标题、期刊名称、卷号和页码。

例如：Smith, J. D. (2010). The impact of climate change on biodiversity. Environmental Science, 15(2), 145-156.在翻译外文文献时，需要注意保持原文的准确性和完整性。

尽量避免意译或添加自己的解释，以免歪曲原文的意思。

同时，还需要在翻译后的文献后面加上“译者”和“翻译日期”的信息，以便读者可以追溯翻译的来源和时间。

其次，对于翻译相关内容的格式，可以参考国际标准组织ISO（International Organization for Standardization）的格式。

这种格式要求在翻译相关内容时，先列出原文，然后是翻译后的文本。

例如：原文：The importance of effective communication in the workplace cannot be overstated.翻译：工作场所有效沟通的重要性不容忽视。

在翻译相关内容时，需要注意保持原文的意思和语气。

尽量使用准确的词汇和语法结构，以便读者能够理解和接受翻译后的内容。

同时，还需要在翻译后的文本后面加上“翻译者”和“翻译日期”的信息，以便读者可以追溯翻译的来源和时间。

此外，对于长篇外文文献的翻译，可以考虑将其分成若干章节，并在每个章节前面加上章节标题。

这样可以使读者更容易理解和阅读翻译后的内容。

毕业设计外文资料翻译原文题目：The Design and Retorfit of Buildings for Resistance to Blast-Induced Progressive Collapse 译文题目：建筑物的设计和改造抵抗由爆炸冲击引起的建筑物的连续倒塌院系名称：土木建筑学院专业班级：土木工程0303班学生姓名：吴建明学号：20034040332指导教师：白杨教师职称：讲师附件： 1.外文资料翻译译文；2.外文原文。

指导教师评语及成绩：签名： 2010年 4月 12日附件1：外文资料翻译译文译文标题（3号黑体，居中）×××××××××（小4号宋体，1.5倍行距）×××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××…………。

（要求不少于3000汉字）建筑物的设计和改造抵抗由爆炸冲击引起的建筑物的连续倒塌1.简介在近现代史中，极端的爆炸事件推动了现有的设计方法和规范重新评估冲击荷载对建筑结构和它们的居住着的影响。

外文翻译器外文翻译器外文翻译器（Machine Translation）是指使用计算机等技术对外文进行自动翻译的工具。

它利用计算机语言处理、人工智能和语言学等多个领域的知识和技术，将源语言（外文）自动转化为目标语言（母语）的过程。

外文翻译器可以帮助人们快速准确地将外文内容转化为自己熟悉的语言，提高工作效率和信息获取能力。

外文翻译器的研究和发展始于上世纪40年代，最早采用的是基于规则的翻译方法，即根据语法规则和词汇库对源语言进行分析和转换。

然而，这种方法存在很多限制，因为语法和词汇库可能无法覆盖所有的语言特点和用法，导致翻译结果不准确和不流畅。

随着计算机技术和人工智能的发展，神经网络机器翻译（Neural Network Translation）成为外文翻译器的主流方法。

这种方法利用大规模平行语料库训练神经网络模型，通过模仿人类学习语言的方式自动学习源语言和目标语言之间的映射关系。

神经网络机器翻译能够更好地处理语法结构和上下文信息，翻译结果更加准确和自然。

除了神经网络机器翻译，外文翻译器还可以采用统计机器翻译（Statistical Machine Translation）等其他方法。

统计机器翻译利用大量的双语语料进行统计分析，找到最佳的翻译候选，然后根据概率模型对其进行排序和选择。

虽然统计机器翻译在一定程度上改善了翻译质量，但由于依赖于大量的语料库，对于某些语言和领域的翻译效果仍然不理想。

当前外文翻译器的发展已经进入了深度学习时代，融合了自然语言处理、深度学习和人工智能的多种技术手段。

深度学习通过建立多层神经网络模型，能够从大规模语料中自动学习和提取特征，进一步提升了翻译质量和效率。

此外，人工智能的发展还带来了一系列辅助工具，如术语提取、句子结构分析和语音识别等，能够进一步提高翻译的准确性和流畅度。

虽然外文翻译器在很大程度上改善了翻译效率和准确性，但由于语言本身的复杂性和多义性，完全依靠机器翻译仍然存在一些局限性。

论文外文翻译指导日志
翻译要求：
1、选定外文文献后先给指导老师看，得到老师的确认通过后方可翻译。

2、选择外文翻译时一定选择外国作者写的文章，可从学校中知网或者外文数据库下载。

3、外文翻译字数要求3000字以上，从外文文章起始处开始翻译，不允许从文章中间部分开始翻译，翻译必须结束于文章的一个大段落。

参考文献是在学术研究过程中，对某一著作或论文的整体的参考或借鉴。

征引过的文献在注释中已注明,不再出现于文后参考文献中。

外文参考文献就是指论文是引用的文献原文是国外的，并非中国的。

原文就是指原作品,原件，即作者所写作品所用的语言。

如莎士比亚的《罗密欧与朱丽叶》原文是英语。

译文就是翻译过来的文字，如在中国也可以找到莎士比亚《罗密欧与朱丽叶》的中文版本，这个中文版本就称为译文。

主要标准
翻译是语际交流过程中沟通不同语言的桥梁。

一般来说，翻译的标准主要有两条：忠实和通顺。

忠实
是指忠实于原文所要传递的信息，也就是说，把原文的信息完整并且准确地表达出来，使译文读者得到的信息与原文读者得到的信息大致相同。

通顺
是指译文规范、明白易懂，没有文理不通、结构混乱、逻辑不清的现象。

外文翻译范例在全球化日益加深的今天，外文翻译的重要性愈发凸显。

无论是学术研究、商务交流，还是文化传播，准确而流畅的外文翻译都起着至关重要的桥梁作用。

下面为大家呈现几个不同领域的外文翻译范例，以帮助大家更好地理解和掌握外文翻译的技巧与要点。

一、科技文献翻译原文：The development of artificial intelligence has brought about revolutionary changes in various fields, such as healthcare, finance, and transportation译文：人工智能的发展给医疗保健、金融和交通运输等各个领域带来了革命性的变化。

在这个范例中，翻译准确地传达了原文的意思。

“artificial intelligence”被准确地翻译为“人工智能”，“revolutionary changes”翻译为“革命性的变化”，“various fields”翻译为“各个领域”，用词准确、贴切，符合科技文献严谨、客观的语言风格。

二、商务合同翻译原文：This Agreement shall commence on the effective date and shall continue in force for a period of five years, unless earlier terminated in accordance with the provisions herein译文：本协议自生效日起生效，并将持续有效五年，除非根据本协议的规定提前终止。

商务合同的翻译需要格外注重准确性和专业性。

上述译文中，“commence”翻译为“生效”，“in force”翻译为“有效”，“terminated”翻译为“终止”，清晰准确地表达了合同条款的含义，避免了可能的歧义。

三、文学作品翻译原文：The sun was setting, painting the sky with hues of orange and pink, as if nature were a master artist at work译文：太阳正在西沉，把天空涂成了橙色和粉色，仿佛大自然是一位正在创作的艺术大师。

2. WHAT CONSTITUTES FAIR DEALINGWEINBERGER v. UOP, INC.457 A.2d 701 (Del.Supr.19a3).MOORE, JUSTICE.This post-trial appeal was reheard en banc from a decision of the Court of Chancery. It was brought by the class action plaintiff below, a former shareholder of UOP, Inc., who challenged the elimination of UOP's minority shareholders by a cash-out merger between UOP and its majority owner, The Signal Companies, Inc. Originally, the defendants in this action were Signal, UOP, certain officers and directors of those companies, and UOP's investment banker, Lehman Brothers Kuhn Loeb, Inc. The present Chancellor held that the terms of the merger were fair to the plaintiff and the other minority shareholders of UOP. Accordingly, he entered judgment in favor of the defendants.Numerous points were raised by the parties, but we address only the following questions presented by the trial court's opinion:1) The plaintiffs duty to plead sufficient facts demonstrating the unfairness of the challenged merger;2) The burden of proof upon the parties where the merger has been approved by the purportedly informed vote of a majority of the minority shareholders;3) The fairness of the merger in terms of adequacy of the defendants' disclosures to the minority shareholders;4) The fairness of the merger in terms of adequacy of the price paid for the minority shares and the remedy appropriate to that issue; and5) The continued force and effect of Singer v. Magnavox Co., Del.Supr., 380 A.2d 969, 980 (1977), and its progeny.In ruling for the defendants, the Chancellor re-stated his earlier conclusion that the plaintiff in a suit challenging a cash-out merger must allege specific acts of fraud, misrepresentation or other items of misconduct to demonstrate the unfairness of the merger terms to the minority. We approve this rule and affirm it.The Chancellor also held that even though the ultimate burden of proof is on the majority shareholder to show by a preponderance of the evidence that the transaction is fair, it is first the burden of the plaintiff attacking the merger to demonstrate some basis for invoking the fairness obligation. We agree with that principle. However, where corporate action has been approved by an informed vote of a majority of the minority shareholders, we conclude that the burden entirely shifts ^ to the plaintiff to show that the transaction was unfair to the minority^- But in all this, the burden clearly remains on those relying on the vote to show that they completely disclosed all material facts relevant to the transaction.Here, the record does not support a conclusion that the minority stockholder vote was an informed one. Material information, necessary to acquaint those shareholders with the bargaining positions of Signal and UOP, was withheld under circumstances amounting to a breach of fiduciary duty. We therefore conclude that this merger does not meet the test of fairness, at least as we address that concept, and no burden thus shifted to the plaintiff by reason of the minority shareholder vote. Accordingly, we reverse and remand for further proceedings consistent herewith.In considering the nature of the remedy available under our law to minority shareholders in a cash-out merger, we believe that it is, and hereafter should be, an appraisal under 8 Del.C. § 262 as hereinafter construed. We therefore overrule Lynch v. Vickers Energy Corp., Del. Supr., 429 A.2d 497 (1981) {Lynch II) to the extent that it purports to limit a stockholder's monetary relief to a specific damage formula. But to give full effect to section 262 within the framework of the General Corporation Law we adopt a more liberal, less rigid and stylized, approach to the valuation process than has heretofore been permitted by our courts. While the present state of these proceedings does not admit the plaintiff to the appraisal remedy per se, the practical effect of the remedy we do grant him will be co-extensive with the liberalized valuation and appraisal methods we herein approve for cases coming after this decision.Our treatment of these matters has necessarily led us to a reconsideration of the business purpose rule announced in the trilogy of Singer A v. Magnavox Co., supra; Tanzer v. International General Industries, JT > Inc., DeL.Supr., 379 A.2d 1121 (1977); and Roland International Corp. v. Najjar, Del.Supr., 407 A.2d 1032 (1979). For the reasons hereafter set forth we consider that the business purpose requirement of these cases v J is no longer the law of Delaware.The facts found by the trial court, pertinent to the issues before us, are supported by the record, and we draw from them as set out in the Chancellor's opinion.Signal is a diversified, technically based company operating through various subsidiaries. Its stock is publicly traded on the New York, Philadelphia and Pacific Stock Exchanges. UOP, formerly known as Universal Oil Products Company, was a diversified industrial company engaged in various lines of business, including petroleum and petro-chemical services and related products, construction, fabricated metal products, transportation equipment products, chemicals and plastics, and other products and services including land development, lumber products and waste disposal. Its stock was publicly held and listed on the New York Stock Exchange.In 1974 Signal sold one of its wholly-owned subsidiaries for $420,000,000 in cash. See Gimbel v. Signal Companies, Inc., Del.Ch., 316 A.2d 599, aff’d, Del.Supr., 316 A.2d 619 (1974). While looking to invest this cash surplus, Signal became interested in UOP as a possible acquisition. Friendly negotiations ensued, and Signal proposed to acquire a controlling interest in UOP at a price of $19 per share. UOP's representatives sought $25 per share. In the arm's length bargaining that followed, an understanding was reached whereby Signal agreed to purchase from UOP 1,500,000 shares of UOP's authorized but unissued stock at $21 per share.This purchase was contingent upon Signal^ making a successful cash tender offer for 4,300,000 publicly held shares of UOP, also at a price of $21 per share. This combined method of acquisition permitted Signal to acquire 5,800,000 shares of stock, representing 50.5% of UOP's outstanding shares. The UOP board of directors advised the company's shareholders that it had no objection to Signal's tender offer at that price. Immediately before the announcement of the tender offer, UOP's common stock had been trading on the New York Stock Exchange at a fraction under $14 per share.The negotiations between Signal and UOP occurred during April 1975, and the resulting tender offer was greatly oversubscribed. However, Signal limited its total purchase of the tendered shares so that, when coupled with the stock bought from UOP, it had achieved its goalof becoming a 50.5% shareholderAlthough UOP’ board consisted of thirteen directors, Signal nominated and elected only six. Of these, five were either directors or employees of Signal. The sixth, a partner in the banking firm of Lazard Freres & Co., had been one of Signal's representatives in the negotiations and bargaining with UOP concerning the tender offer and purchase price of the UOP shares.However, the president and chief executive officer of UOP retired during 1975, and Signal caused him to be replaced by James V. Crawford, a long-time employee and senior executive vice president of one of Signal's wholly-owned subsidiaries. Crawford succeeded his predecessor on UOP's board of directors and also was made a director of Signal.By the end of 1977 Signal basically was unsuccessful in finding other suitable investment candidates for its excess cash, and by February 1978 considered that it had no other realistic acquisitions available to it on a friendly basis. Once again its attention turned to UOP.The trial court found that at the instigation of certain Signal management personnel, including William W. Walkup, its board chairman, and Forrest N. Shumway, its president, a feasibility study was made concerning the possible acquisition of the balance of UOP's outstanding shares. This study was performed by two Signal officers, Charles S. Arledge, vice president (director of planning), and Andrew J. Chitiea, senior vice president (chief financial officer). Messrs. Walkup, Shumway, Arledge and Chitiea were all directors of UOP in addition to their membership on the Signal board.Arledge and Chitiea concluded that it would be a good investment for Signal to acquire the remaining 49.5% of UOP shares at any price up to $24 each. Their report was discussed between Walkup and Shumway who, along with Arledge, Chitiea and Brewster L. Arms, internal counsel for Signal, constituted Signal's senior management. In particular, they talked about the proper price to be paid if the acquisition was pursued, purportedly keeping in mind that as UOP's majority shareholder, Signal owed a fiduciary responsibility to both its own stockholders as well as to UOP's minority. It was ultimately agreed that a meeting of Signal's Executive Committee would be called to propose that Signal acquire the remaining outstanding stock of UOP through a cash-out merger in the range of $20 to $21 per share.The Executive Committee meeting was set for February 28, 1978. As a courtesy, UOP's president, Crawford, was invited to attend, although he was not a member of Signal's executive committee. On his arrival, and prior to the meeting, Crawford was asked to meet privately with Walkup and Shumway. He was then told of Signal's plan to acquire full ownership of UOP and was asked for his reaction to the proposed price range of $20 to $21 per share. Crawford said he thought such a price would be "generous", and that it was certainly one which should be submitted to UOP's minority shareholders for their ultimate consideration. He stated, however, that Signal's 100% ownership could cause internal problems at UOP. He believed that employees would have to be given some assurance of their future place in a fully- owned Signal subsidiary. Otherwise, he feared the departure of essential personnel. Also, many of UOP's key employees had stock option incentive programs which would be wiped out by a merger. Crawford therefore urged that some adjustment would have to be made, such as providing a comparable incentive in Signal's shares, if after the merger he was to maintain his quality of personnel and efficiency at UOP.Thus, Crawford voiced no objection to the $20 to $21 price range, nor did he suggest that Signal should consider paying more than $21 per share for the minority interests. Later, at the Executive Committee meeting the same factors were discussed, with Crawford repeating the position he earlier took with Walkup and Shumway. Also considered was the 1975 tender offer andthe fact that it had been greatly oversubscribed at $21 per share. For many reasons, Signal's manage¬ment concluded that the acquisition of UOP's minority shares provided the solution to a number of its business problems.Thus, it was the consensus that a price of $20 to $21 per share would be fair to both Signal and the minority shareholders of UOP. Signal's executive committee authorized its management "to negotiate" with UOP "for a cash acquisition of the minority ownership in UOP, Inc., with the intention of presenting a proposal to [Signal's] board of directors * * * on March 6, 1978". Immediately after this February 28, 1978 meeting, Signal issued a press release stating: The Signal Companies, Inc. and UOP, Inc. are conducting negotiations for the acquisition for cash by Signal of the 49.5 per cent of UOP which it does not presently own, announced Forrest N. Shumway, president and chief executive officer of Signal, and James V. Crawford, UOP president. Price and other terms of the proposed transaction have not y et been finalized and would be subject to approval of the boards of directors of Signal and UOP, scheduled to meet early next week, the stockholders of UOP and certain federal agencies.The announcement also referred to the fact that the closing price of UOP's common stock on that day was $14.50 per share.Two days later, on March 2, 1978, Signal issued a second press release stating that its management would recommend a price in the range of $20 to $21 per share for UOP's 49.5% minority interest. This announcement referred to Signal's earlier statement that "negotiations" were being conducted for the acquisition of the minority shares.Between Tuesday, February 28, 1978 and Monday, March 6,1978, a total of four business days, Crawford spoke by telephone with all of UOP's non-Signal, i.e., outside, directors. Also during that period, Crawford retained Lehman Brothers to render a fairness opinion as to the price offered the minority for its stock. He gave two reasons for this choice. First, the time schedule between the announcement and the board meetings was short (by then only three business days) and since Lehman Brothers had been acting as UOP's investment banker for many years, Crawford felt that it would be in the best position to respond on such brief notice. Second, James W. Glanville, a long-time director of UOP and a partner in Lehman Brothers, had acted as a financial advisor to UOP for many years. Crawford believed that Glanville's familiarity with UOP, as a member of its board, would also be of assistance in enabling Lehman Brothers to render a fairness opinion within the existing time constraints.Crawford telephoned Glanville, who gave his assurance that Lehman Brothers had no conflicts that would prevent it from accepting the task. Glanville's immediate personal reaction was that a price of $20 to $21 would certainly be fair, since it represented almost a 50% premium over UOP's market price. Glanville sought a $250,000 fee for Lehman Brothers' services, but Crawford thought this too much. After further discussions Glanville finally agreed that Lehman Brothers would render its fairness opinion for $150,000.During this period Crawford also had several telephone contacts with Signal officials. In only one of them, however, was the price of the shares discussed. In a conversation with Walkup, Crawford advised that as a result of his communications with UOP's non-Signal directors, it was his feeling that the price would have to be the top of the proposed range, or $21 per share, if the approval of UOP's outside directors was to be obtained. But again, he did not seek any price higher than $21.Glanville assembled a three-man Lehman Brothers team to do the work on the fairness opinion. These persons examined relevant documents and information concerning UOP, including its annual reports and its Securities and Exchange Commission filings from 1973 through 1976, as well as its audited financial statements for 1977, its interim reports to shareholders, and its recent and historical market prices and trading volumes. In addition, on Friday, March 3, 1978, two members of the Lehman Brothers team flew to UOP's headquarters in Des Plaines, Illinois, to perform a "due diligence" visit, during the course of which they interviewed Crawford as well as UOP's general counsel, its chief financial officer, and other key executives and personnel.As a result, the Lehman Brothers team concluded that "the price of either $20 or $21 would be a fair price for the remaining shares of UOP". They telephoned this impression to Glanville, who was spending the weekend in Vermont.On Monday morning, March 6, 1978, Glanville and the senior member of the Lehman Brothers team flew to Des Plaines to attend the scheduled UOP directors meeting. Glanville looked over the assembled information during the flight. The two had with them the draft of a "fairness opinion letter" in which the price had been left blank. Either during or immediately prior to the directors' meeting, the two-page "fairness opinion letter" was typed in final form and the price of $21 per share was inserted.On March 6, 1978, both the Signal and UOP boards were convened to consider the proposed merger. Telephone communications were maintained between the two meetings. Walkup, Signal's board chairman, and also a UOP director, attended UOP's meeting with Crawford in order to present Signal's position and answer any questions that UOP's non-Signal directors might have. Arledge and Chitiea, along with Signal's other designees on UOP's board, participated by conference telephone. All of UOP's outside directors attended the meeting either in person or by conference telephone.First, Signal's board unanimously adopted a resolution authorizing Signal to propose to UOP a cash merger of $21 per share as outlined in a certain merger agreement, and other supporting documents. This proposal required that the merger be approved by a majority of UOP's outstanding minority shares voting at the stockholders meeting at which the merger would be considered, and that the minority shares voting in favor of the merger, when coupled with Signal's 50.5% interest would have to comprise at least two-thirds of all UOP shares. Otherwise the proposed merger would be deemed disapproved.UOP's board then considered the proposal. Copies of the agreement were delivered to the directors in attendance, and other copies had been forwarded earlier to the directors participating by telephone. They also had before them UOP financial data for 1974-1977, UOP's most recent financial statements, market price information, and budget projections for 1978. In addition they had Lehman Brothers' hurriedly prepared fairness opinion letter finding the price of $21 to be fair. Glanville, the Lehman Brothers partner, and UOP director, commented on the information that had gone into preparation of the letter.Signal also suggests that the Arledge-Chitiea feasibility study, indicating that a price of up to $24 per share would be a "good investment" for Signal, was discussed at the UOP directors' meeting. The Chancellor made no such finding, and our independent review of the record, detailed infra, satisfies us by a preponderance of the evidence that there was no discussion of this document at UOP's board meeting. Furthermore, it is clear beyond peradventure that nothing in that report was ever disclosed to UOP's minority shareholders prior to their approval of themerger.After consideration of Signal's proposal, Walkup and Crawford left the meeting to permit a free and uninhibited exchange between UOP's non-Signal directors. Upon their return a resolution to accept Signal's offer was then proposed and adopted. While Signal's men on UOP's board participated in various aspects of the meeting, they abstained from voting. However, the minutes show that each of them "if voting would have voted yes".On March 7, 1978, UOP sent a letter to its shareholders advising them of the action taken by UOP's board with respect to Signal's offer. This document pointed out, among other things, that on February 28, 1978 "both companies had announced negotiations were being conducted".Despite the swift board action of the two companies, the merger was not submitted to UOP's shareholders until their annual meeting on May 26, 1978. In the notice of that meeting and proxy statement sent to shareholders in May, UOP's management and board urged that the merger be approved. The proxy statement also advised:The price was determined after discussions between James V. Crawford, a director of Signal and Chief Executive Officer of UOP, and officers of Signal which took place during meetings on February 28, 1978, and in the course of several subsequent telephone conversations. (Emphasis added.)In the original draft of the proxy statement the word "negotiations" had been used rather than "discussions". However, when the Securities and Exchange Commission sought details of the "negotiations" as part of its review of these materials, the term was deleted and the word "discussions" was substituted. The proxy statement indicated that the vote of UOP's board in approving the merger had been unanimous. It also advised the shareholders that Lehman Brothers had given its opinion that the merger price of $21 per share was fair to UOP's minority. However, it did not disclose the hurried method by which this conclusion was reached.As of the record date of UOP's annual meeting, there were 11,488,302 shares of UOP common stock outstanding, 5,688,302 of which were owned by the minority. At the meeting only 56%, or 3,208,652, of the minority shares were voted. Of these, 2,953,812, or 51.9% of the total minority, voted for the merger, and 254,840 voted against it. When Signal's stock was added to the minority shares voting in favor, a total of 76.2% of UOP's outstanding shares approved the merger while only 2.2% opposed it.By its terms the merger became effective on May 26, 1978, and each share of UOP's stock held by the minority was automatically converted into a right to receive $21 cash.II.A.A primary issue mandating reversal is the preparation by two UOP directors, Arledge and Chitiea, of their feasibility study for the exclusive use and benefit of Signal. This document was of obvious significance to both Signal and UOP. Using UOP data, it described the advantages to Signal of ousting the minority at a price range of $21-$24 per share. Mr. Arledge, one of the authors, outlined the benefits to Signal:Purpose Of The Merger1) Provides an outstanding investment opportunity for Signal—(Better than any recent acquisition we have seen.)2) Increases Signal's earnings.3) Facilitates the flow of resources between Signal and its subsidiaries(Big factor—works both ways.)4) Provides cost savings potential for Signal and UOP.5) Improves the percentage of Signal's 'operating earnings' as opposed to 'holding company earnings'.6) Simplifies the understanding of Signal.7) Facilitates technological exchange among Signal's subsidiaries.8) Eliminates potential conflicts of interest.Having written those words, solely for the use of Signal it is clear from the record that neither Arledge nor Chitiea shared this report with their fellow directors of UOP. We are satisfied that no one else did either. This conduct hardly meets the fiduciary standards applicable to such a transaction * * *The Arledge-Chitiea report speaks for itself in supporting the Chancellor's finding that a price of up to $24 was a "good investment" for Signal. It shows that a return on the investment at $21 would be 15.7% versus 15.5% at $24 per share. This was a difference of only two-tenths of one percent, while it meant over $17,000,000 to the minority. Under such circumstances, paying UOP's minority shareholders $24 would have had relatively little long-term effect on Signal, and the Chancellor's findings concerning the benefit to Signal, even at a price of $24, were obviously correct. Levitt v. Bouvier, Del.Supr., 287 A.2d 671, 673 (1972).Certainly, this was a matter of material significance to UOP and its shareholders. Since the study was prepared by two UOP directors, using UOP information for the exclusive benefit of Signal, and nothing whatever was done to disclose it to the outside UOP directors or the minority shareholders, a question of breach of fiduciary duty arises. This problem occurs because there were common Signal-UOP directors participating, at least to some extent, in the UOP board's decision making processes without full disclosure of the conflicts they faced.7B.In assessing this situation, the Court of Chancery was required to:examine what information defendants had and to measure it against what they gave to the minority stockholders, in a context in which 'complete candor' is required. In other words, the limited function of the Court was to determine whether defendants had disclosed all information in their possession germane to the transaction in issue. And by 'germane' we mean, for present purposes, information such as a reasonable shareholder would consider important. in Priding whether. to sell or retain stock.* * ** * * Completeness, not adequacy, is both the norm and the mandate under present circumstances. Lynch v. Vickers Energy Corp., Del.Supr., 383 A.2d 278, 281 (1977) (Lynch /). This is merely stating in another way the long-existing principle of Delaware law that these Signal designated directors on UOP's board still owed UOP and its shareholders an uncompromising duty of loyalty. The classic language of Guth v. Loft, Inc., Del.Supr., 5 A.2d 503, 510 (1939), requires no embellishment:A public policy, existing through the years, and derived from a profound knowledge of human characteristics and motives, has established a rule that demands of a corporate officer or director, peremptorily and inexorably, the most scrupulous observance of his duty, not only affirmatively to protect the interests of the corporation committed to his charge, but also to refrainfrom doing anything that would work injury to the corporation, or to deprive it of. profit or advantage which his skill and ability might properly bring to it, or to enable it to make in the reasonable and lawful exercise of its powers. The rule that requires an undivided and unselfish loyalty to the corporation demands that there shall be no conflict between duty and self-interest. Given the absence of any attempt to structure this transaction on an arm's length basis, Signal cannot escape the effects of the conflicts it faced, particularly when its designees on UOP's board did not totally abstain from participation in the matter. There is no "safe harbor" for such divided loyalties in Delaware. When directors of a Delaware ^ corporation are on both sides of a transaction, they are required to demonstrate their utmost good faith and the most scrupulous inherent P fairness of the bargain. Gottlieb v. Heyden Chemical Corp., Del.Supr., 91 A.2d 57, 57-58 (1952). The requirement of fairness is unflinching in v rP y demand that where one stands on both sides of a transaction, he has the burden of establishing its entire fairness, sufficient to pass the test of careful scrutiny by the courts. Sterling v. Mayflower Hotel Corp., N, Del.Supr., 93 A.2d 107, 110 (1952); Bastian v. Bourns, Inc., Del.Ch., 256 A.2d 680, 681 (1969), aff’d, Del.Supr., 278 A.2d 467 (1970); David J. Greene & Co. v. Dunhill International Inc., Del.Ch., 249 A.2d 427, 431 (1968).There is no dilution of this obligation where one holds dual or multiple directorships, as in a parent-subsidiary context. Levien v. Sinclair Oil Corp., Del.Ch., 261 A.2d 911, 915 (1969). Thus, individuals who act in a dual capacity as directors of two corporations, one of whom is parent and the other subsidiary, owe the same duty of good management to both corporations, and in the absence of an independent negotiating structure (see note 7, supra), or the directors' total abstention from any participation in the matter, this duty is to be exercised in light of what is best for both companies. Warshaw v. Calhoun, Del. Supr., 221 A.2d 487, 492 (1966). The record demonstrates that Signal has not met this obligation.。

DOI10.1007/s10711-012-9699-zORIGINAL PAPERParking garages with optimal dynamicsMeital Cohen·Barak WeissReceived:19January2011/Accepted:22January2012©Springer Science+Business Media B.V.2012Abstract We construct generalized polygons(‘parking garages’)in which the billiard flow satisfies the Veech dichotomy,although the associated translation surface obtained from the Zemlyakov–Katok unfolding is not a lattice surface.We also explain the difficulties in constructing a genuine polygon with these properties.Keywords Active vitamin D·Parathyroid hormone-related peptide·Translation surfaces·Parking garages·Veech dichotomy·BilliardsMathematics Subject Classification(2000)37E351Introduction and statement of resultsA parking garage is an immersion h:N→R2,where N is a two dimensional compact connected manifold with boundary,and h(∂N)is afinite union of linear segments.A parking garage is called rational if the group generated by the linear parts of the reflections in the boundary segments isfinite.If h is actually an embedding,the parking garage is a polygon; thus polygons form a subset of parking garages,and rationals polygons(i.e.polygons all of whose angles are rational multiples ofπ)form a subset of rational parking garages.The dynamics of the billiardflow in a rational polygon has been intensively studied for over a century;see[7]for an early example,and[5,10,13,16]for recent surveys.The defi-nition of the billiardflow on a polygon readily extends to a parking garage:on the interior of N the billiardflow is the geodesicflow on the unit tangent bundle of N(with respect to the pullback of the Euclidean metric)and at the boundary,theflow is defined by elastic reflection (angle of incidence equals the angle of return).Theflow is undefined at thefinitely many M.Cohen·B.Weiss(B)Ben Gurion University,84105Be’er Sheva,Israele-mail:barakw@math.bgu.ac.ilM.Cohene-mail:comei@bgu.ac.ilpoints of N which map to‘corners’,i.e.endpoints of boundary segments,and hence at thecountable union of codimension1submanifolds corresponding to points in the unit tangentbundle for which the corresponding geodesics eventually arrive at corners in positive or neg-ative time.Since the direction of motion of a trajectory changes at a boundary segment viaa reflection in its side,for rational parking garages,onlyfinitely many directions of motionare assumed.In other words,the phase space of the billiardflow decomposes into invarianttwo-dimensional subsets corresponding tofixing the directions of motion.Veech[12]discovered that the billiardflow in some special polygons exhibits a strikingly he found polygons for which,in any initial direction,theflow is eithercompletely periodic(all orbits are periodic),or uniquely ergodic(all orbits are equidistrib-uted).Following McMullen we will say that a polygon with these properties has optimaldynamics.We briefly summarize Veech’s strategy of proof.A standard unfolding construc-tion usually attributed to Zemlyakov and Katok[15]1,associates to any rational polygon Pa translation surface M P,such that the billiardflow on P is essentially equivalent to thestraightlineflow on M P.Associated with any translation surface M is a Fuchsian group M,now known as the Veech group of M,which is typically trivial.Veech found M and P forwhich this group is a non-arithmetic lattice in SL2(R).We will call these lattice surfaces and lattice polygons respectively.Veech investigated the SL2(R)-action on the moduli space of translation surfaces,and building on earlier work of Masur,showed that lattice surfaces haveoptimal dynamics.From this it follows that lattice polygons have optimal dynamics.This chain of reasoning remains valid if one starts with a parking garage instead of apolygon;namely,the unfolding construction associates a translation surface to a parkinggarage,and one may define a lattice parking garage in an analogous way.The arguments ofVeech then show that the billiardflow in a lattice parking garage has optimal dynamics.Thisgeneralization is not vacuous:lattice parking garages,which are not polygons,were recentlydiscovered by Bouw and Möller[2].The term‘parking garage’was coined by Möller.A natural question is whether Veech’s result admits a converse,i.e.whether non-latticepolygons or parking garages may also have optimal dynamics.In[11],Smillie and the sec-ond-named author showed that there are non-lattice translation surfaces which have optimaldynamics.However translation surfaces arising from billiards form a set of measure zero inthe moduli space of translation surfaces,and it was not clear whether the examples of[11]arise from polygons or parking garages.In this paper we show:Theorem1.1There are non-lattice parking garages with optimal dynamics.An example of such a parking garage is shown in Fig.1.Veech’s work shows that for lattice polygons,the directions in which all orbits are periodicare precisely those containing a saddle connection,i.e.a billiard path connecting corners ofthe polygon which unfold to singularities of the corresponding surface.Following Cheunget al.[3],if a polygon P has optimal dynamics,and the periodic directions coincide with thedirections of saddle connections,we will say that P satisfies strict ergodicity and topologicaldichotomy.It is not clear to us whether our example satisfies this stronger property.As weexplain in Remark3.2below,this would follow if it were known that the center of the regularn-gon is a‘connection point’in the sense of Gutkin,Hubert and Schmidt[8]for some nwhich is an odd multiple of3.Veech also showed that for a lattice polygon P,the number N P(T)of periodic strips on P of length at most T satisfies a quadratic growth estimate of the form N P(T)∼cT2for a positive constant c.As we explain in Remark3.3,our examples also satisfy such a quadratic growth estimate.1But dating back at least to Fox and Kershner[7].Fig.1A non-lattice parkinggarage with optimal dynamics.(Here 2/n represents angle 2π/n )It remains an open question whether there is a genuine polygon which has optimal dynam-ics and is not a lattice polygon.Although our results make it seem likely that such a polygon exists,in her M.Sc.thesis [4],the first-named author obtained severe restrictions on such a polygon.In particular she showed that there are no such polygons which may be constructed from any of the currently known lattice examples via the covering construction as in [11,13].We explain these results and prove a representative special case in §4.2PreliminariesIn this section we cite some results which we will need,and deduce simple consequences.For the sake of brevity we will refer the reader to [10,11,16]for definitions of translation surfaces.Suppose S 1,S 2are compact orientable surfaces and π:S 2→S 1is a branched cover.That is,πis continuous and surjective,and there is a finite 1⊂S 1,called the set of branch points ,such that for 2=π−1( 1),the restriction of πto S 2 2is a covering map of finite degree d ,and for any p ∈ 1,#π−1(p )<d .A ramification point is a point q ∈ 2for which there is a neighborhood U such that {q }=U ∩π−1(π(q ))and for all u ∈U {q },# U ∩π−1(π(u )) ≥2.If M 1,M 2are translation surfaces,a translation map is a surjective map M 2→M 1which is a translation in charts.It is a branched cover.In contrast to other authors (cf.[8,13]),we do not require that the set of branch points be distinct from the singularities of M 1,or that they be marked.It is clear that the ramification points of the cover are singularities on M 2.If M is a lattice surface,a point p ∈M is called periodic if its orbit under the group of affine automorphisms of M is finite.A point p ∈M is called a connection point if any seg-ment joining a singularity with p is contained in a saddle connection (i.e.a segment joining singularities)on M .The following proposition summarizes results discussed in [7,9–11]:Proposition 2.1(a)A non-minimal direction on a translation surface contains a saddle connection.(b)If M 1is a lattice surface,M 2→M 1is translation map with a unique branch point,then any minimal direction on M 2is uniquely ergodic.(c)If M2→M1is a translation map such that M1is a lattice surface,then all branchpoints are periodic if and only if M2is a lattice surface.(d)If M2→M1is a translation map with a unique branch point,such that M1is a latticesurface and the branch point is a connection point,then any saddle connection direction on M2is periodic.Corollary2.2Let M2→M1be a translation map such that M1is a lattice surface with a unique branch point p.Then:(1)M2has optimal dynamics.(2)If p is a connection point then M2satisfies topological dichotomy and strict ergodicity.(3)If p is not a periodic point then M2is not a lattice surface.Proof To prove(1),by(b),the minimal directions are uniquely ergodic,and we need to prove that the remaining directions are either completely periodic or uniquely ergodic. By(a),in any non-minimal direction on M2there is a saddle connectionδ,and there are three possibilities:(i)δprojects to a saddle connection on M1.(ii)δprojects to a geodesic segment connecting the branch point p to itself.(iii)δprojects to a geodesic segment connecting p to a singularity.In case(i)and(ii)since M1is a lattice surface,the direction is periodic on M1,hence on M2as well.In case(iii),there are two subcases:ifδprojects to a part of a saddle connec-tion on M1,then it is also a periodic direction.Otherwise,in light of Proposition2.1(a),the direction must be minimal in M1,and hence,by Proposition2.1(b),uniquely ergodic in M2. This proves(1).Note also that if p is a connection point then the last subcase does not arise, so all directions which are non-minimal on M2are periodic.This proves(2).Statement(3) follows from(c).We now describe the unfolding construction[7,15],extended to parking garages.Let P=(h:N→R2).An edge of P is a connected subset L of∂N such that h(L)is a straight segment and L is maximal with these properties(with respect to inclusion).A vertex of P is any point which is an endpoint of an edge.The angle at a vertex is the total interior angle, measured via the pullback of the Euclidean metric,at the vertex.By convention we always choose the positive angles.Note that for polygons,angles are less than2π,but for parking garages there is no apriori upper bound on the angle at a vertex.Since our parking garages are rational,all angles are rational multiples ofπ,and we always write them as p/q,omitting πfrom the notation.Let G P be the dihedral group generated by the linear parts of reflections in h(L),for all edges L.For the sake of brevity,if there is a reflection with linear part gfixing a line parallel to L,we will say that gfixes L.Let S be the topological space obtained from N×G P by identifying(x,g1)with(x,g2)whenever g−11g2fixes an edge containing h(x).Topologically S is a compact orientable surface,and the immersions g◦h on each N×{g}induce an atlas of charts to R2which endows S with a translation surface structure.We denote this translation surface by M P,and writeπP for the map N×G P→M P.We will be interested in a‘partial unfolding’which is a variant of this construction,in which we reflect a parking garage repeatedly around several of its edges to form a larger parking garage.Formally,suppose P=(h:N→R2)and Q=(h :N →R2)are parking garages.For ≥1,we say that P tiles Q by reflections,and that is the number of tiles,if the following holds.There are maps h 1,...h :N→N and g1,...,g ∈G P(not necessarily distinct)satisfying:(A)The h i are homeomorphisms onto their images,and N = h i (N ).(B)For each i ,the linear part of h ◦h i ◦h −1is everywhere equal to g i .(C)For each 1≤i <j ≤ ,let L i j =h i (N )∩h j (N )and L =(h i )−1(L i j ).Then (h j )−1◦h i is the identity on L ,and L is either empty,or a vertex,or an edge of P .If L is an edge then h i (N )∪h j (N )is a neighborhood of L i j.If L i j is a vertex then there is a finite set of i =i 1,i 2,...,i k =j such that h i s (N )contains a neighborhood of L i j ,and each consecutive pair h i t (N ),h i t +1(N )intersect along an edge containing L i j .V orobets [13]realized that a tiling of parking garages gives rise to a branched cover.More precisely:Proposition 2.3Suppose P tiles Q by reflections with tiles,M P ,M Q are the correspond-ing translation surfaces obtained via the unfolding construction,and G P ,G Q are the cor-responding reflection groups.Then there is a translation map M Q →M P ,such that the following hold:(1)G Q ⊂G P .(2)The branch points are contained in the G P -orbit of the vertices of P .(3)The degree of the cover is [G P :G Q ].(4)Let z ∈M P be a point which is represented (as an element of N ×{1,...,r })by(x ,k )with x a vertex in P with angle m n (where gcd (m ,n )=1).Let (y i )⊂M Q be the pre-images of z,with angles k i m n in Q .Then z is a branch point of the cover if and only if k i n for some i.Proof Assertion (1)follows from the fact that Q is tiled by P .Since this will be impor-tant in the sequel,we will describe the covering map M Q →M P in detail.We will map (x ,g )∈N ×G Q to πP (x ,gg i )∈M P ,where x =h i (x ).We now check that this map is independent of the choice of x ,i ,and descends to a well-defined map M Q →M P ,which is a translation in charts.If x =h i (x 1)=h j (x 2)then x 1=x 2since (h i )−1◦h j is the identity.If x is in the relative interior of an edge L i j thenπP (x ,gg i )=πP (x ,gg j )(1)since (gg i )−1gg j =g −1i g j fixes an edge containing h (x 1).If x 1is a vertex of P then one proves (1)by an induction on k ,where k is as in (C).This shows that the map is well-defined.We now show that it descends to a map M Q →M P .Suppose (x ,g ),(x ,g )are two points in N ×G Q which are identified in M Q ,i.e.x ∈∂N is in the relative interior of an edge fixed by g −1g .By (C)there is a unique i such that x is in the image of h i .Thus (x ,g )maps to (x ,gg i )and (x ,g )maps to (x ,g g i ),and g −1i g −1g g i fixes the edge through x =g −1i (x ).It remains to show that the map we have defined is a translation in charts.This follows immediately from the chain rule and (B).Assertion (2)is simple and left to the reader.For assertion (3)we note that M P (resp.M Q )is made of |G P |(resp. |G Q |)copies of P .The point z will be a branch point if and only if the total angle around z ∈M P differs from the total angle around one of the pre-images y i ∈M Q .The total angle at a singularity corresponding to a vertex with angle r /s (where gcd (r ,s )=1)is 2r π,thus the total angle at z is 2m πand the total angle at y i is 2k i m πgcd (k i ,n ).Assertion (4)follows.3Non-lattice dynamically optimal parking garagesIn this section we prove the following result,which immediately implies Theorem1.1: Theorem3.1Let n≥9be an odd number divisible by3,and let P be an isosceles triangle with equal angles1/n.Let Q be the parking garage made of four copies of P glued as in Fig.1, so that Q has vertices(in cyclic order)with angles1/n,2/n,3/n,(n−2)/n,2/n,3(n−2)/n. Then M P is a lattice surface and M Q→M P is a translation map with one aperiodic branchpoint.In particular Q is a non-lattice parking garage with optimal dynamics.Proof The translation surface M P is the double n-gon,one of Veech’s original examples of lattice surfaces[12].The groups G P and G Q are both equal to the dihedral group D n.Thus by Proposition2.3,the degree of the cover M Q→M P is four.Again by Proposition2.3, since n is odd and divisible by3,the only vertices which correspond to branch points are the two vertices z1,z2with angle2/n(they correspond to the case k i=2while the other vertices correspond to1or3).In the surface M P there are two points which correspond to vertices of equal angle in P(the centers of the two n-gons),and these points are known to be aperiodic [9].We need to check that z1and z2both map to the same point in M P.This follows from the fact that both are opposite the vertex z3with angle3/n,which also corresponds to the center of an n-gon,so in M P project to a point which is distinct from z3. Remark3.2As of this writing,it is not known whether the center of the regular n-gon is a connection point on the double n-gon surface.If this turns out to be the case for some n which is an odd multiple of3,then by Corollary2.2(2),our construction satisfies strict ergodicity and topological dichotomy.See[1]for some recent related results.Remark3.3Since our examples are obtained by taking branched covers over lattice surfaces, a theorem of Eskin et al.[6,Thm.8.12]shows that our examples also satisfy a quadratic growth estimate of the form N P(T)∼cT2;moreover§9of[6]explains how one may explicitly compute the constant c.4Non-lattice optimal polygons are hard tofindIn this section we present results indicating that the above considerations will not easily yield a non-lattice polygon with optimal dynamics.Isolating the properties necessary for our proof of Theorem3.1,we say that a pair of polygons(P,Q)is suitable if the following hold:•P is a lattice polygon.•P tiles Q by reflections.•The corresponding cover M Q→M P as in Proposition2.3has a unique branch point which is aperiodic.In her M.Sc.thesis at Ben Gurion University,thefirst-named author conducted an exten-sive search for a suitable pair of polygons.By Corollary2.2,such a pair will have yielded a non-lattice polygon with optimal dynamics.The search begins with a list of candidates for P,i.e.a list of currently known lattice polygons.At present,due to work of many authors, there is a fairly large list of known lattice polygons but there is no classification of all lattice polygons.In[4],the full list of lattice polygons known as of this writing is given,and the following is proved:Theorem4.1(M.Cohen)Among the list of lattice surfaces given in[4],there is no P for which there is Q such that(P,Q)is a suitable pair.The proof of Theorem4.1contains a detailed case-by-case analysis for each of the differ-ent possible P.These cases involve some common arguments which we will illustrate in this section,by proving the special case in which P is any of the obtuse triangles investigated byWard[14]:Theorem4.2For n≥4,let P=P n be the(lattice)triangle with angles1n,12n,2n−32n.Then there is no polygon Q for which(P,Q)is a suitable pair.Our proof relies on some auxiliary statements which are of independent interest.In all of them,M Q→M P is the branched cover with unique branch point corresponding to a suitable pair(P,Q).These statements are also valid in the more general case in which P,Q are parking garages.Recall that an affine automorphism of a translation surface is a homeomorphism which is linear in charts.We denote by Aff(M)the group of affine automorphisms of M and by D:Aff(M)→GL2(R)the homomorphism mapping an affine automorphism to its linear part.Note that we allow orientation-reversing affine automorphisms,i.e.detϕmay be1 or−1.We now explain how G P acts on M P by translation equivalence.LetπP:N×G P→M P and S be as in the discussion preceding Proposition2.3,and let g∈G P.Since the left action of g on G is a permutation and preserves the gluing ruleπP,the map N×G P→N×G P sending(x,g )to(x,g−1g )induces a homeomorphismϕ:S→S and g◦h◦ϕis a translation in charts.Thus g∈G P gives a translation isomorphism of M P,and similarly g∈G P gives a translation isomorphism of M Q.Lemma4.3The branch point of the cover p:M Q→M P isfixed by G Q.Proof Since G Q⊂G P,any g∈G Q induces translation isomorphisms of both M P and M Q.We denote both by g.The definition of p given in thefirst paragraph of the proof of Proposition2.3shows that p◦g=g◦p;namely both maps are induced by sending (x ,g )∈N ×G Q toπP(x,gg g i),where x =h i(x).Since the cover p has a unique branch point,any g∈G Q mustfix it. Lemma4.4If an affine automorphismϕof a translation surface has infinitely manyfixed points then Dϕfixes a nonzero vector,in its linear action on R2.Proof Suppose by contradiction that the linear action of Dϕon the plane has zero as a uniquefixed point,and let Fϕbe the set offixed points forϕ.For any x∈Fϕwhich is not a singularity,there is a chart from a neighborhood U x of x to R2with x→0,and a smaller neighborhood V x⊂U x,such thatϕ(V x)⊂U x and when expressed in this chart,ϕ|V x is given by the linear action of Dϕon the plane.In particular x is the onlyfixed point in V x. Similarly,if x∈Fϕis a singularity,then there is a neighborhood U x of x which maps to R2 via afinite branched cover ramified at x→0,such that the action ofϕin V x⊂U x covers the linear action of Dϕ.Again we see that x is the onlyfixed point in V x.By compactness wefind that Fϕisfinite,contrary to hypothesis. Lemma4.5Suppose M is a lattice surface andϕ∈Aff(M)has Dϕ=−Id.Then afixed point forϕis periodic.Proof LetF1={σ∈Aff(M):Dσ=−Id}.Thenϕ∈F1and F1isfinite,since it is a coset for the group ker D which is known to be finite.Let A⊂M be the set of points which arefixed by someσ∈F1.By Lemma4.4this is afinite set,which contains thefixed points forϕ.Thus in order to prove the Lemma,it suffices to show that A is Aff(M)-invariant.Letψ∈Aff(M),and let x∈A,so that x=σ(x)with Dσ=−Id.Since-Id is central in GL2(R),D(σψ)=D(ψσ),so there is f∈ker D such thatψσ=fσψ.Thereforeψ(x)=ψσ(x)=fσψ(x),and fσ∈F1.This proves thatψ(x)∈A.Remark4.6This improves Theorem10of[8],where a similar conclusion is obtained under the additional assumptions that M is hyperelliptic and Aff(M)is generated by elliptic ele-ments.The following are immediate consequences:Corollary4.7Suppose(P,Q)is a suitable pair.Then•−Id/∈D(G Q).•None of the angles between two edges of Q are of the form p/q with gcd(p,q)=1and q even.Proof of Theorem4.2We will suppose that Q is such that(P,Q)are a suitable pair and reach a contradiction.If n is even,then Aff(M P)contains a rotation byπwhichfixes the points in M P coming from vertices of P.Thus by Lemma4.5all vertices of P give rise to periodic points,contradicting Proposition2.1(c).So n must be odd.Let x1,x2,x3be the vertices of P with corresponding angles1/n,1/2n,(2n−3)/2n. Then x3gives rise to a singularity,hence a periodic point.Also using Lemma4.5and the rotation byπ,one sees that x2also gives rise to a periodic point.So the unique branch point must correspond to the vertex x1.The images of the vertex x1in P give rise to two regular points in M P,marked c1,c2in Fig.2.Any element of G P acts on{c1,c2}by a permutation, so by Lemma4.3,G Q must be contained in the subgroup of index twofixing both of the c i. Let e1be the edge of P opposite x1.Since the reflection in e1,or any edge which is an image of e1under G P,swaps the c i,we have:e1is not a boundary edge of Q.(2) We now claim that in Q,any vertex which corresponds to the vertex x3from P is alwaysdoubled,i.e.consists of an angle of(2n−3)/n.Indeed,for any polygon P0,the group G P0 is the dihedral group D N where N is the least common multiple of the denominators of theangles at vertices of P0.In particular it contains-Id when N is even.Writing(2n−3)/2n in reduced form we have an even denominator,and since,by Corollary4.7,−Id/∈G Q,in Q the angle at vertex x3must be multiplied by an even integer2k.Since2k(2n−3)/2n is bigger than2if k>1,and since the total angle at a vertex of a polygon is less than2π,we must have k=1,i.e.any vertex in Q corresponding to the vertex x3is always doubled.This establishes the claim.It is here that we have used the assumption that Q is a polygon and not a parking garage.Fig.2Ward’s surface,n=5Fig.3Two options to start the construction ofQThere are two possible configurations in which a vertex x3is doubled,as shown in Fig.3. The bold lines indicate lines which are external,i.e.boundary edges of Q.By(2),the con-figuration on the right cannot occur.Let us denote the polygon on the left hand side of Fig.3by Q0.It cannot be equal to Q,since it is a lattice polygon.We now enlarge Q0by adding copies of P step by step,as described in Fig.4.Without loss of generality wefirst add triangle number1.By(2),the broken line indicates a side which must be internal in Q.Therefore,we add triangle number 2.We denote the resulting polygon by Q1.One can check by computing angles,using thefact that n is odd,and using Proposition2.3(4)that the cover M Q1→M P will branch overthe points a corresponding to vertex x2.Since the allowed branching is only over the points corresponding to x1,we must have Q1 Q,so we continue the construction.Without loss of generality we add triangle number3.Again,by(2),the broken line indicates a side which must be internal in Q.Therefore,we add triangle number4,obtaining Q2.Now,using Prop-osition2.3(4)again,in the cover M Q2→M P we have branching over two vertices u andv which are both of type x1and correspond to distinct points c1and c2in M P.This implies Q2 Q.Fig.4Steps of the construction of QSince both vertices u and v are delimited by2external sides,we cannot change the angle to prevent the branching over one of these points.This means that no matter how we continue to construct Q,the branching in the cover M Q→M P will occur over at least two points—a contradiction.Acknowledgments We are grateful to Yitwah Cheung and Patrick Hooper for helpful discussions,and to the referee for a careful reading and helpful remarks which improved the presentation.This research was supported by the Israel Science Foundation and the Binational Science Foundation.References1.Arnoux,P.,Schmidt,T.:Veech surfaces with non-periodic directions in the tracefield.J.Mod.Dyn.3(4),611–629(2009)2.Bouw,I.,Möller,M.:Teichmüller curves,triangle groups,and Lyapunov exponents.Ann.Math.172,139–185(2010)3.Cheung,Y.,Hubert,P.,Masur,H.:Topological dichotomy and strict ergodicity for translation surfaces.Ergod.Theory Dyn.Syst.28,1729–1748(2008)4.Cohen,M.:Looking for a Billiard Table which is not a Lattice Polygon but satisfies the Veech dichotomy,M.Sc.thesis,Ben-Gurion University(2010)/pdf/1011.32175.DeMarco,L.:The conformal geometry of billiards.Bull.AMS48(1),33–52(2011)6.Eskin,A.,Marklof,J.,Morris,D.:Unipotentflows on the space of branched covers of Veech surfaces.Ergod.Theorm Dyn.Syst.26(1),129–162(2006)7.Fox,R.H.,Kershner,R.B.:Concerning the transitive properties of geodesics on a rational polyhe-dron.Duke Math.J.2(1),147–150(1936)8.Gutkin,E.,Hubert,P.,Schmidt,T.:Affine diffeomorphisms of translation surfaces:Periodic points,Fuchsian groups,and arithmeticity.Ann.Sci.École Norm.Sup.(4)36,847–866(2003)9.Hubert,P.,Schmidt,T.:Infinitely generated Veech groups.Duke Math.J.123(1),49–69(2004)10.Masur,H.,Tabachnikov,S.:Rational billiards andflat structures.In:Handbook of dynamical systems,vol.1A,pp.1015–1089.North-Holland,Amsterdam(2002)11.Smillie,J.,Weiss,B.:Veech dichotomy and the lattice property.Ergod.Theorm.Dyn.Syst.28,1959–1972(2008)Geom Dedicata12.Veech,W.A.:Teichmüller curves in moduli space,Eisenstein series and an application to triangularbilliards.Invent.Math.97,553–583(1989)13.V orobets,Y.:Planar structures and billiards in rational polygons:the Veech alternative.(Russian);trans-lation in Russian Math.Surveys51(5),779–817(1996)14.Ward,C.C.:Calculation of Fuchsian groups associated to billiards in a rational triangle.Ergod.TheoryDyn.Syst.18,1019–1042(1998)15.Zemlyakov,A.,Katok,A.:Topological transitivity of billiards in polygons,Math.Notes USSR Acad.Sci:18:2291–300(1975).(English translation in Math.Notes18:2760–764)16.Zorich,A.:Flat surfaces.In:Cartier,P.,Julia,B.,Moussa,P.,Vanhove,P.(eds.)Frontiers in numbertheory,physics and geometry,Springer,Berlin(2006)123。