外文文献报告格式

第一篇：外文文献报告格式

科技文献检索报告 篇二：文献综述、开题报告、外文翻译格式要求暨模板

文献综述、开题报告、外文翻译格式要求

一、文档格式 1.打印格式

纸张统一用a4纸，页面设置：上：2.7；下：2.7；左：2.7；右：2.7；页眉：1.8；页脚：1.85。文档网络，每行42字符，每页40行；段落格式为：多陪行距，1.25陪，段前、段后均为0磅。

一、二级标题可适当选择加宽，设置为：段前、段后均为6磅。页脚设置为：插入页码，居中。

2.字体设置

文档标题采用楷体_gb2312，三号字体，加粗，居中。

一级标题采用楷体_gb2312，四号字体，加粗，左侧顶格。

二级标题采用宋体，小四号字体，加粗，缩进两个中文字符。

三级标题采用宋体，小四字体，缩进两个中文字符。

正文采用小四号宋体字，数字用阿拉伯数字，字母和数字用times new roman。

二、文献综述

文献综述要求字数在4000字以上，采用学院统一格式，文档标题根据题目类型，标题用“嘉兴学院南湖学院毕业论文文献综述”或“嘉兴学院南湖学院毕业设计文献综述”。页面设置和字体设置按照上述文档格式要求编辑。应按要求认真填写。

（1）文献综述应包括综述题目、综述正文、文献资料等几方面内容；（2）文献综述时，应系统地查阅与自己的研究方向有关的国内外文献，通常阅读文献不少于15篇，其中外文文献不少于2篇；

（3）文献综述中，学生应说明自己研究方向的发展历史，前人的主要研究成果，存在的问题及发展趋势等；

（4）文献综述要条理清晰，文字通顺简练；

（5）资料运用恰当、合理。文献引用用方括号[ ]括起来置于引用词的右上角；（6）综述中要有自己的观点和见解。鼓励学生多发现问题、多提出问题，并指出分析、解决问题的可能途径

注意：主题部分的一级标题题目，应结合毕业论文（设计）的主题来编写。

三、开题报告

开题报告要求字数在4000字以上，采用学院统一格式。文档标题根据题目类型，标题用“嘉兴学院南湖学院毕业论文开题报告”或“嘉兴学院南湖学院毕业设计开题报告”。页面设置和字体设置按照上述文档格式要求编辑。应按要求认真填写，且务必于毕业论文（设计）环节正式开始前完成。

四、外文翻译

要求本科生毕业论文（设计）必须翻译每篇2000单词以上的外文翻译二篇，外文翻译包括外文文献原文和译文，外文原文要尽可能与所做课题紧密联系，避免翻译资料选取的随意性，译文要符合外文格式规范和翻译习惯。

文档标题根据题目类型，标题用“嘉兴学院南湖学院毕业论文外文翻译”或“嘉兴学院南湖学院毕业设计外文翻译”。页面设置和字体设置按照上述文档格式要求编辑。

“abstract：”（小四号times new roman，加粗，顶格），同行接英文摘要原文，五号times new roman字体。

“keywords：”（小四号times new roman，加粗，顶格），同行接关键词，关键词之间用逗号分割，用五号times new roman字体。篇三：毕业论文的选题报告、外文翻译及文献综述的格式和要求

机械与材料工程学院关于毕业设计文献综述的写作要求

为了进一步强化学生搜集文献资料的能力，熟悉专业文献资料查找和资料积累方法，提高对文献资料的归纳、分析、综合运用能力，提高独立工作能力和科研能力，并为科研活动奠定扎实的基础。根据学校要求，毕业设计必须查阅一定的文献资料实施文献综述写作制度。为了进一步规范文献综述的写作，现将文献综述写作要求明确如下：

一、撰写文献综述的基本要求

文献综述是针对某一研究领域或专题搜集大量文献资料的基础上，就国内外在该领域或专题的主要研究成果、最新进展、研究动态、前沿问题等进行综合分析而写成的、能比较全面的反映相关领域或专题历史背景、前人工作、争论焦点、研究现状和发展前景等内容的综述性文章。“综”是要求对文献资料进行综合分析、归纳整理，使材料更精练明确、更有逻辑层次；“述”就是要求对综合整理后的文献进行比较专门的、全面的、深入的、系统的评述。

二、撰写文献综述的基本注意事项

1、文献综述是一篇相对独立的综述性学术报告，包括题目、前言、正文、总结等几个部分。

题目：一般应直接采用《文献综述》作为标题，经指导教师批准也可以所研究题目或主要论题加“文献综述”的方式作为标题。

前言：点明毕业论文（设计）的论题、学术意义以及其与所阅读文献的关系，简要说明文献收集的目的、重点、时空范围、文献种类、核心刊物等方面的内容。

正文：无固定格式，文献综述在逻辑上要合理，可以按文献与毕业论文（设计）主题的关系由远而近进行综述，也可以按年代顺序综述，也可按不同的问题进行综述，还可按不同的观点进行比较综述。总之要根据毕业论文（设计）的具体情况撰写，对毕业论文（设计）所采用的全部参考文献分类、归纳、分析、比较、评述，应特别注意对主流、权威文献学术成果的引用和评述，注意发现已有成果的不足。

结论：对全文的评述做出简明扼要的总结，重点说明对毕业论文（设计）具有启示、借鉴或作为毕业论文（设计）重要论述依据的相关文献已有成果的学术意义、应用价值和不足，提出自己的研究目标。2．要围绕毕业论文主题对文献的各种观点作比较分析，不要教科书式地将与研究课题有关的理论和学派观点简要地汇总陈述一遍。3．评述（特别是批评前人不足）时，要引用原作者的原文（防止对原作者论点的误解），不要贬低别人抬高自己，不能从二手材料来判定原作者的“错误”。4．文献综述结果要说清前人工作的不足，衬托出作进一步研究的必要性和理论价值。5．采用了文献中的观点和内容应注明来源，模型、图表、数据应注明出处，不要含糊不清。

6．文献综述最后要有简要总结，并能准确地反映主题内容，表明前人为该领域研究打下的工作基础。

7．所有提到的参考文献都应和所毕业论文（设计）研究问题直接相关。8．文献综述所用的文献，与毕业设计（论文）的论题直接相关，与毕业论文（设计）的参考文献数量完全一致；重要论点、论据不得以教材、非学术性文

献、未发表文献作为参考文献，应主要选自学术期刊或学术会议的文章，其次是教科书或其他书籍。至于大众传播媒介如报纸、广播、通俗杂志中的文章，一些数据、事实可以引用，但其中的观点不能作为论证问题的依据。

三、撰写文献综述的其他事项 1．一篇毕业论文应完成一篇文献综述，字数规定不少于2000字。2．文献综述所用的文献，至少要求15篇，且外文的至少要求2篇。3．文献综述应包括综述题目、综述正文、文献资料等几方面内容。4．文献综述所引用的参考文献书写格式应符合gb7714－1987《参考文献著录规则》。常用参考文献的书写格式如下：

期刊类格式：作者．文章名．期刊名称，出版年份，卷号（期号）：起止页码．

书籍类格式：作者．书名．版次（第一版应省略）．出版地：出版者，出版年份：起止页码．

论文集类格式：著者．题名．编者．论文集名．出版地：出版者，出版年份：起止页码．

学位论文类格式：作者．题名．保存地：保存单位，年份．

毕业设计文献综述封面及正文见附件

一、附件二

本科毕业设计文献综述

小二号黑体，居中 xxxxxxxxxxxxx 文献综述题目(二号黑体，居中)三号黑体，居中

学 x x x 学 号：专 业：班 级：x x x 指导教师：x x x 小二号黑体，居中 按本科专业目录填写

二o一o 三号黑体，居中

文献综述

前言

本篇毕业设计（论文）题目是《从供应链的角度浅谈光伏产业的问题与对策》。太阳能光伏产业作为清洁能源的主要来源，已经越来越受到政府、企业、研究机构乃至个人的重视，为了发现光伏产业在现代中国的利用意义和价值，实现人与自然的可持续发展，本文着力研究光伏产业供应链的两端：上游供应链即多晶硅的采购，下游供应链即太阳能光伏产品的销售物流。面对光伏产业“两头在外”的尴尬局面，即原料的采购和产品的销售很大程度上依存于国外市场，本文从供应链的角度，利用图书资料、互联网信息、企业调查等方法，探求中国光伏企业的未来发展方向，最后又以南京中电集团为例，简述该企业在光伏行业中未来的发展之路。

正文

能源的紧缺，已经成为目前世界范围内的热门话题。从长远战略上考虑，开发和利用太阳能成为了各国可持续发展战略的重要组成部分。太阳能是一种既丰富又无污染的可再生能源，通过太阳能电池将光能转化成电能，也就是我们所说的太阳能光伏产业。世界各国都对太阳能光伏产业给予了前所未有的重视。国家发改委能源研究所专家预测，我国太阳能电池装机容量的年增长率有望超过40%。到2020年，系统年产值将接近3000亿元。与此相应，我国光伏产业必然会有极大的发展空间。

1、光伏产业供应链的基本情况

整个光伏产业主要包括多晶硅原料、太阳能电池、集成组件、发电工程四个相关的行业。供应链主要包括硅材料（主要是多晶硅）的生产和供应，电池片制造—组件—系统封装与应用，光伏产品的分销。其中，进入壁垒最高的环节为太阳能级晶体硅的生产，由于其技术与工艺上的难度，目前基本被国际上7大厂家垄断，这属于产业链上游环节。多晶硅的需求主要来自于半导体和太阳能电池。按纯度要求不同，分为电子级和太阳能级。其中，用于电子级多晶硅占55％左右，太阳能级多晶硅占45％，随着光伏产业的迅猛发展，太阳能电池对多晶硅需求量的增长速度高于半导体多晶硅的发展，预计从2008年，太阳能多晶硅的需求量将超过电子级多晶硅。

2、光伏产业发展趋势

由于光伏产业巨大的发展前景以及现阶段硅材料供不应求引起的价格大幅上涨，许多投资者和政府、企业对该行业表示出极大的兴趣。资料显示，2005年，每公斤多晶硅价格仅为66美元，到2007年12月，已上升为每公斤400美元的天价。在刚刚过去的2007年，多晶硅引起了市场的充分关注。在市场缺口加大、价格不断上扬的刺激下，国内又一次涌现出投资多晶硅项目热潮。

在这股热潮下，一部分专家指出，中国面临着大量产能上马将逐渐填补供给缺口，但未来可能存在过剩的风险；还有一部分专家则认为，过剩节点难以预测拐点 最终取决未来太阳能需求。但是不容忽视的是，某些地区不顾当地的实际情况，追逐眼前利益，有盲目上马多晶硅项目的趋势。

3、光伏产业的从供应链角度所存在的问题

概括来说，是以下3种情况。上游供应链——卖方市场，中游供应链——两头在外，下游供应链——买方市场。

具体来说，国内多晶硅生产企业在产业化方面的差距主要表现在以下几个方面： 3.1 产能低，上游和中游供需矛盾突出。2005年中国太阳能用单晶硅企业开工率在20％－30％，半导体用单晶硅企业开工率在80％－90％，无法实现满负荷生产，多晶硅技术和市场仍牢牢掌握在美、日、德国的少数几个生产厂商中，严重制约我国产业发展。3.2 上游硅材料企业生产规模小。现在公认的最小经济规模为1000吨/年，最佳经济规模在2500吨/年，而我国现阶段多晶硅生产企业离此规模仍有较大的距离。工艺设备落后，同类产品物料和电力消耗过大，三废问题多，与国际水平相比，国内多晶硅生产物耗能耗高出1倍以上，产品成本缺乏竞争力。3.3 行业供应链及地区供应链不够健全。地方政府和企业项目投资多晶硅项目，存在低水平重复建设的隐忧。3.4 下游市场在外。技术和市场被国外控制，存在“两头在外”的尴尬局面。中国光伏产业采购成本高，销售利润薄，有趋向于“代工生产”的趋势。

4、如何解决问题 4.1 发展壮大我国多晶硅产业的市场条件已经基本具备、时机已经成熟，篇四：调研报告和外文翻译格式

毕 业

设 计

调研（开题）报告

题 目: 院系名称： 土木建筑学院 专业班级：工程管理040×班

学生姓名： 学 号：

日 1．调研（开题）报告适合于工程管理专业完成毕业设计类题目的学生（招投标文件编制、施工组织设计、工程量清单、可行性研究等），并作为毕业设计（论文）答辩委员会对学生答辩资格审查的依据材料之一。此报告应在指导教师指导下，由学生在毕业设计（论文）工作前期内完成，经指导教师签署意见及所在专业审查后生效。2．调研（开题）报告内容必须用黑墨水笔工整书写或按教务处统一设计的电子文档标准格式（可从教务处网页上下载）打印，禁止打印在其它纸上后剪贴，完成后应及时交给指导教师签署意见。3．调研（开题）报告应按论文的格式成文，调研（开题）报告应是对拟完成的设计题目的一个或多个相似工程或相应的文档资料进行的认真考察并适度参与完后完成的总结，主要内容应该涵盖拟建工程（文档资料）的基本材料、特点和难点，以及得到的体会。调研（开题）报告可适度有一些参考文献，主要是关于同类研究的工程进展和异同点，以及对拟完成的设计借鉴意义。4．有关年月日等日期的填写，应当按照国标gb/t 7408—94《数据元和交换格式、信息交换、日期和时间表示法》规定的要求，一律用阿拉伯数字书写。如“2006年11月20日”或“2006-11-30”。

毕业设计调研（开题）报告 篇五：文献综述、开题报告、外文翻译格式要求暨模板 嘉兴学院

文献综述、开题报告、外文翻译格式要求

一、文档格式 1.打印格式

纸张统一用a4纸，页面设置：上：2.7；下：2.7；左：2.7；右：2.7；页眉：1.8；页脚：1.85。文档网络，每行42字符，每页40行；段落格式为：多陪行距，1.25陪，段前、段后均为0磅。

一、二级标题可适当选择加宽，设置为：段前、段后均为6磅。页脚设置为：插入页码，居中。

2.字体设置

文档标题采用楷体_gb2312，三号字体，加粗，居中。

一级标题采用楷体_gb2312，四号字体，加粗，左侧顶格。

二级标题采用宋体，小四号字体，加粗，缩进两个中文字符。

三级标题采用宋体，小四字体，缩进两个中文字符。

正文采用小四号宋体字，数字用阿拉伯数字，字母和数字用times new roman。

二、文献综述

文献综述要求字数在4000字以上，采用学院统一格式，文档标题根据题目类型，标题用“嘉兴学院毕业论文文献综述”或“嘉兴学院毕业设计文献综述”。页面设置和字体设置按照上述文档格式要求编辑。应按要求认真填写。

（1）文献综述应包括综述题目、综述正文、文献资料等几方面内容；（2）文献综述时，应系统地查阅与自己的研究方向有关的国内外文献，通常阅读文献不少于15篇，其中外文文献不少于2篇；

（3）文献综述中，学生应说明自己研究方向的发展历史，前人的主要研究成果，存在的问题及发展趋势等；

（4）文献综述要条理清晰，文字通顺简练；

（5）资料运用恰当、合理。文献引用用方括号[ ]括起来置于引用词的右上角；

（6）综述中要有自己的观点和见解。鼓励学生多发现问题、多提出问题，并指出分析、解决问题的可能途径

注意：主题部分的一级标题题目，应结合毕业论文（设计）的主题来编写。

三、开题报告

开题报告要求字数在4000字以上，采用学院统一格式。文档标题根据题目类型，标题用“嘉兴学院毕业论文开题报告”或“嘉兴学院毕业设计开题报告”。页面设置和字体设置按照上述文档格式要求编辑。应按要求认真填写，且务必于毕业论文（设计）环节正式开始前完成。

四、外文翻译

要求本科生毕业论文（设计）必须翻译每篇2000单词以上的外文翻译二篇，外文翻译包括外文文献原文和译文，外文原文要尽可能与所做课题紧密联系，避免翻译资料选取的随意性，译文要符合外文格式规范和翻译习惯。

文档标题根据题目类型，标题用“嘉兴学院毕业论文外文翻译”或“嘉兴学院毕业设计外文翻译”。页面设置和字体设置按照上述文档格式要求编辑。“abstract：”（小四号times new roman，加粗，顶格），同行接英文摘要原文，五号times new roman字体。

“keywords：”（小四号times new roman，加粗，顶格），同行接关键词，关键词之间用逗号分割，用五号times new roman字体。

第二篇：食品安全外文文献

Food safety is affected by the decisions of producers, processors, distributors, food service operators, and consumers, as well as by government regulations.In developed countries, the demand for higher levels of food safety has led to the implementation of regulatory programs that address more types of safety-related attributes(such as bovine spongiform encephalopathy(BSE), microbial pathogens, environmental contaminants, and animal drug and pesticide residues)and impose stricter standards for those attributes.They also further prescribe how safety is to be assured and communicated.Liability systems are another form of regulation that affect who bears responsibility when food safety breaks down.These regulatory programs are intended to improve public health by controlling the quality of the domestic food supply and the increasing flow of imported food products from countries around the world.Common to the adoption of new regulations by developed countries is the application of risk analysis principles.Under these principles, and in line with the World Trade Organization’s(WTO’s)Agreement on the Application of Sanitary and Phytosanitary Measures(SPS Agreement), countries should base their regulatory actions on scientific risk assessment.In addition, a country should be able to clearly link its targeted level of protection, based on a scientifically assessed risk level, to its regulatory goals and, in turn, to its standards and inspection systems.Finally, the risk management options chosen should restrict trade as little as possible.Despite similarities in approach among developed countries, to date they have made only mixed progress toward aligning their regulatory requirements.Countries are struggling with the task of identifying key risk issues and choosing regulatory programs to control those risks.They emphasize different risks, apply different levels of precaution, and choose different regulatory approaches.The regulatory systems of countries are a mix of old laws and newer regulations that frequently do not apply consistent standards across products, risks, or countries of origin.Finally, countries may be tempted to use food safety regulations as a means of protecting domestic industries from foreign competition.These features of food safety regulation in developed countries have several implications for developing countries.First, they determine access to growing markets for food exports, particularly high-value fresh commodities such as those discussed in other briefs in this collection.When standards differ, this can create additional barriers for developingcountry exporters.Second, these features determine the issues that will be addressed in international forums, such as the Codex Alimentarius Commission.Third, they create expectations among developing-country consumers regarding acceptable levels of safety and set examples for emerging regulations in developing-country food systems.This brief reviews emerging regulatory approaches and the implications for developing countries.REGULATORY APPROACHES Countries regulate food safety through the use of process, product(performance), or information standards.Process standards specify how the product should be produced.For example, Good Manufacturing Practices specify in-plant design, sanitation, and operation standards.Product(performance)standards require that final products have specific characteristics.An example is the specification of a maximum microbial pathogen load for fresh meats and poultry.Finally, information standards specify the types of labeling or other communication that must accompany products.While these categories provide a neat breakdown, in practice most countries use a combination of approaches to regulate any particular food safety risk.For example, specifications for acceptable in-plant operations may be backed up with final product testing to monitor and verify the success of safety assurance programs.Labeling that instructs final consumers on proper food handling techniques may further back up these systems.MAJOR REGULATORY TRENDS IN DEVELOPED COUNTRIES • Stronger public health and consumer welfare emphasis in decisions by regulatory agencies.The increasing use of the risk analysis framework for regulatory decision-making focuses attention on the effective control of public health risks as the ultimate goal of regulations, rather than intermediate steps such as assuring that accepted practices are used in production.This in turn leads to a focus on the food supply chain, on identifying where hazards are introduced into it, and on determining where those hazards can be controlled most cost effectively in the chain.This approach is referred to as “farm to table” or “farm to fork” analysis.When the supply chain extends across international borders, risk analysis may encompass farm or processing practices in developing countries.• Adoption of more stringent safety standards, with a broader scope of standards.Food safety standards are becoming more stringent in developed countries on two fronts.First, in many cases food safety attributes that were previously regulated are being held to more precise and stringent standards.For example, rather than assuring meat product safety simply through process standards, those products may be required to meet specific pathogen load standards for E.coli or Salmonella.Similarly, tolerances for aflatoxin may be lowered as more information and better testing become readily available.Second, the scope of standards is broadening, as new risks become known.For example, the European Union, the United States, and other countries have instituted strict feeding restrictions to avoid the spread of BSE in cattle.In addition, the European Union has recently established a regulatory program to control human exposure to dioxins through the food supply.These evolving standards create continuing challenges for producers and regulatory agencies in exporting countries.• Adoption of the HACCP approach to assuring safety.During the 1990s, developed countries made a strong shift toward requiring the Hazard Analysis Critical Control Point(HACCP)approach to assuring food safety.Under HACCP, companies are responsible for analyzing how hazards such as food-borne pathogens may enter the product, establishing effective control points for those hazards, and monitoring and updating the system to assure high levels of food safety.These HACCP systems are usually predicated on the processing plant having an adequate system of sanitary operating procedures already in place.HACCP does not prescribe specific actions to be taken in a plant: the company chooses its methods for controlling hazards.HACCP systems make clear that the central responsibility for assuring safety belongs to a company;the regulator’s job is often shifted from one of direct inspection to providing oversight for the company’s operation of its HACCP plan.Since HACCP is primarily a process standard for company-level activity, inspection to assure compliance is challenging for imported products coming from plants in other countries.Some countries, such as those in the European Union, have mandated HACCP for all levels of the food supply chain, while others such as the United States have mandated it for specific sectors(meat slaughter and processing, for example).• Adoption of hybrid regulatory systems.Mandatory HACCP may be combined with performance standards for finished products.The performance standards(a minimum incidence of Salmonella in finished products, for example)provide a check on whether the HACCP plan is performing adequately.The increased use of performance standards has been facilitated by the development of more accurate and speedier testing procedures, particularly for pathogens.Eventually such tests may make it easier for exporters to demonstrate and verify a particular level of safety.食品安全受生产者、加工者、经销商、餐饮服务经营者决策的影响，也受到消费者和政府法规的影响。在发达国家，对更高水平的食品安全的需求导致监管的程序需要处理更多类型的与安全相关的属性（如牛海绵状脑病(BSE)、病原微生物、环境污染物和动物的药物和农药残留）并且执行施加更严格的标准。他们还进一步规定安全是如何被确保和传达的。责任制度是当食品安全发生问题的时候谁负有责任的另一种管理形式。这些监管程序旨在通过控制国内粮食供应量和不断增加来自世界各地的进口食品来改善公共卫生。风险分析原理是由发达国家共同通过的新条例的应用。根据符合《世界贸易组织协定》和《 实施动植物卫生检疫措施的协议》（SPS 协定）这些原则，国家应该以监管行为为基础进行科学的风险评估。此外，一个国家应当有能力在其科学的风险的评估的基础上，明确将其对产品的保护能力与其制定标准和检查系统联系起来，进而达到其监管目的。最后，选择风险管理方案应该尽可能减少贸易。到目前为止，在发达国家采取了相似的方法，在调整他们的监管要求方面取得了一定的进展。各个国家都在努力确定风险问题的关键，并且选择相应的监管程序来控制这些风险。他们强调不同的风险，需要运用不同等级的预防措施，也需要选择不同的监管方法。国家的监管制度混合了旧的法律和新的法规，通常不适用于贯穿产品、风险或原籍国的标准。最后，国家可能会使用食品安全法规作为保护国内工业免受外国竞争的一种手段。发达国家食品安全监管的这些特点对发展中国家的食品安全监管有多方面的启示。首先，他们决定增长食品出口市场，特别是高价值新鲜的商品，在此集合中与其他概要一起讨论。当标准不同时，就可以为发展中国家出口制造更多的障碍。其次，这些特征决定了在食品法典委员会等国际论坛将讨论的问题。第三，他们在发展中国家粮食系统中创建发展中国家消费者关于可接受水平的安全和新兴规章设定的举例寄予了厚望。这个概要回顾了新兴的监管方式及对发展中国家的影响。监管办法：各国通过使用流程、产品（性能）或信息标准规范食品安全。工艺标准规定如何生产产品。例如，良好的生产规范中规定了工厂的设计，卫生和操作标准。产品（性能）标准要求最终产品要有特定的特性。一个例子就是一个最大的微生物病原体负载的新鲜肉类和家禽的规范。最后，信息标准指定的标签，必须伴随着产品类型的其他交流。虽然这些类别为灵活的故障作好了准备，但是在实践中大多数的国家都会使用各种方法的组合来控制特定食品安全的风险。例如，工厂运营中的规范可能得到最终产品的测试，一次来监测和核查安全保证项目的成功。标签的指示最终会使消费者对正确的食物处理技术系统进行进一步的支持。主要所监管的趋势都在发达国家，强有力的公众健康和消费者福利重点，是由监管机构所决定的。监管监管决策的风险分析框架越来越多地使用，增加关注的公共卫生风险的有效控制才是制度的终极目标，而不是像用于被确保用于生产地做法这种中间步骤。这反过来导致焦点在食品供应链中，它有被确定的危害，并确定在哪里可以最控制这些危险成本并且有效地在供应链中。这种方法称为“农场到餐桌”或“农场到餐桌”分析。当供应链延伸跨越国届的时候，包括农场或处理做法的风险分析可能会在发展中国家。• 采用更严格的安全标准，具有更广泛的标准范围。发达国家的食品安全标准日趋变得更加严格。首先，在许多情况下以前是如何规定食品安全的属性被提升至到更精确和更严格的标准。举个例子，不是确保肉类产品安全只是通过程序标准，而是这些产品可能需要满足特定病原体荷载标准为大肠杆菌或沙门氏菌。同样，随着更多的信息和更好的检测变得随时可用，就一降低堆黄曲霉毒素的公差。其次，因为新的风险变得已知，标准的范围正在扩大。例如，欧洲联盟、美国和其他国家制定了严格的饲养限制，以避免疯牛病传播。此外，欧洲联盟最近成立一个监管的程序来控制人类通过食品供应所接触的二恶英（化学污染物）。这些不断发展的标准为生产国和出口国的管理机构创造持续的挑战。• 通过 HACCP 方法保证安全。在上世纪90年代，发达国家作出强烈转向要求保证食品安全的危害分析关键控制点(HACCP)方法。按照 HACCP，公司负责分析如何把食源性致病菌危害尽可能输入产品，有效的控制要点和监测和更新系统，以保证高水平的食品安全。这些 HACCP 系统通常取决于加工厂有适当的到位的卫生操作程序制度。HACCP并没有规定所采取的设备具体的行动，公司选择其控制危害的方法。HACCP 系统明确保证安全中心责任属于公司；从直接检验之上，监管机构的工作经常被转移到监督为公司的操作提供其 HACCP 计划。由于 HACCP是以公司活动级别的过程主要标准，检查以确保来自工厂的其他国家的进口产品遵从法规，是具有挑战性的。一些国家，例如在欧洲联盟，有授权 HACCP 为各级食品供应链，而其他如美国是授权具体门（例如，肉类屠宰和加工）。• 通过混合监管系统。强制性HACCP可能结合成品性能标准。性能标准（例如，在成品沙门氏菌的发生率最低）的提供对 HACCP 计划是否充分执行进行了检查。通过更准确和更快的测试程序，特别是对病原菌的发展促进了增加的使用性能标准。最终这种测试可能方便出口商证明和核实特定级别的安全。

第三篇：外文文献注释规范

外文文献注释规范

引证外文文献，原则上以该文种通行的引证标注方式为准。

引证英文文献的标注项目与顺序与中文相同。责任者与题名间用英文逗号，著作题名为斜体，析出文献题名为正体加英文引号，出版日期为全数字标注，责任方式、卷册、页码等用英文缩略方式；期刊文章题名为正体加英文引号，登载的刊物题名为斜体。

单页为p.79.两页以上为pp.79-90.两个p

示例1：专著

Randolph Starn and Loren Partridge, The Arts of Power: Three Halls of State in Italy, 1300-1600, Berkeley: California University Press, 1992, pp.19-28.示例2： 译著

M.Polo, The Travels of Marco Polo, trans.by William Marsden,Hertfordshire: Cumberland House, 1997, pp.55, 88.示例3： 主编

T.H.Aston and C.H.E.Phlipin(eds.), The Brenner Debate.Cambridge: Cambridge University Press, 1985, p.35.示例4： 析出文献

R.S.Schfield, “The Impact of Scarcity and Plenty on Population Change in England,” in R.I.Rotberg and T.K.Rabb(eds.), Hunger and History: The Impact of Changing Food Production and Consumption Pattern on Societ，Cambridge: Cambridge University Press, 1983, p.79.示例5： 期刊

Heath B.Chamberlain, “On the Search for Civil Society in China”, Modern China, vol.19, no.2(April 1993), pp.199-215.

第四篇：财务风险 外文文献

外文文献

The Important Of Financial Risk

Sohnke M.Bartram Gregory W.Brown and Murat Atamer

Abstract:This paper examines the determinants of equity price risk for a largesample of non-financial corporations in the United States from 1964 to 2008.Weestimate both structural and reduced form models to examine the endogenous natureof corporate financial characteristics such as total debt debt maturity cash holdingsand dividend policy.We find that the observed levels of equity price risk areexplained primarily by operating and asset characteristics such as firm age size assettangibility as well as operating cash flow levels and volatility.In contrast impliedmeasures of financial risk are generally low and more stable than debt-to-equity ratios.Our measures of financial risk have declined over the last 30 years even as measuresof equity volatility e.g.idiosyncratic risk have tended to increase.Consequentlydocumented trends in equity price risk are more than fully accounted for by trends inthe riskiness of firms’ assets.Taken together the results suggest that the typical U.S.firm substantially reduces financial risk by carefully managing financial policies.As aresult residual financial risk now appears negligible relative to underlying economicrisk for a typical non-financial firm.Keywords：Capital structure； financial risk； risk management；corporate finance1

1.Introduction

The financial crisis of 2008 has brought significant attention to the effects offinancial leverage.There is no doubt that the high levels of debt financing by financialinstitutions and households significantly contributed to the crisis.Indeed evidenceindicates that excessive leverage orchestrated by major global banks e.g.through themortgage lending and collateralized debt obligations and the so-called “shadowbanking system” may be the underlying cause of the recent economic and financialdislocation.Less obvious is the role of financial leverage among nonfinancial firms.To date problems in the U.S.non-financial sector have been minor compared to thedistress in the financial sector despite the seizing of capital markets during the crisis.For example non-financial bankruptcies have been limited given that the economicdecline is the largest since the great depression of the 1930s.In fact bankruptcyfilings of non-financial firms have occurred mostly in U.S.industries e.g.automotive manufacturing newspapers and real estate that faced fundamentaleconomic pressures prior to the financial crisis.This surprising fact begs the question“How important is financial risk for non-financial firms” At the heart of this issue isthe uncertainty about the determinants of total firm risk as well as components of firmrisk.Recent academic research in both asset pricing and corporate finance hasrekindled an interest in analyzing equity price risk.A current strand of the assetpricing literature examines the finding of Campbell et al.2001 that

firm-specificidiosyncratic risk has tended to increase over the last 40 years.Other work suggeststhat idiosyncratic risk may be a priced risk factor see Goyal and Santa-Clara 2003among others.Also related to these studies is work by Pástor and Veronesi 2003showing how investor uncertainty about firm profitability is an important determinantof idiosyncratic risk and firm value.Other research has examined the role of equityvolatility in bond pricing e.g.Dichev 1998 Campbell Hilscher and Szilagyi2008.However much of the empirical work examining equity price risk takes the riskof assets as given or tries to explain the trend in idiosyncratic risk.In contrast thispaper takes a different tack in the investigation of equity price risk.First we seek tounderstand the determinants of equity price risk at the firm level by considering totalrisk as the product of risks inherent in the firms operations i.e.economic or businessrisks and risks associated with financing the firms operations i.e.financial risks.Second we attempt to assess the relative importance of economic and financial risksand the implications for financial policy.Early research by Modigliani and Miller 1958 suggests that financial policymay be largely irrelevant for firm value because investors can replicate manyfinancial decisions by the firm at a low cost i.e.via homemade leverage andwell-functioning capital markets should be able to distinguish between financial andeconomic distress.Nonetheless financial policies such as adding debt to the capitalstructure can magnify the risk of equity.In contrast recent research on corporate riskmanagement suggests that firms may also be able to reduce risks and increase valuewith financial policies such as hedging with financial derivatives.However thisresearch is often motivated by substantial deadweight costs associated with financialdistress or other market imperfections associated with financial leverage.Empiricalresearch provides conflicting accounts of how costly financial distress can be for atypical publicly traded firm.We attempt to directly address the roles of economic and financial risk byexamining determinants of total firm risk.In our analysis we utilize a large sample ofnon-financial firms in the United States.Our goal of identifying the most importantdeterminants of equity price risk volatility relies on viewing financial policy astransforming asset volatility into equity volatility via financial leverage.Thusthroughout the paper we consider financial leverage as the wedge between assetvolatility and equity volatility.For example in a static setting debt provides financialleverage that magnifies operating cash flow volatility.Because financial policy isdetermined by owners and managers we are careful to examine the effects of firms’asset and operating characteristics on financial policy.Specifically we examine avariety of characteristics suggested by previous research and as clearly as possibledistinguish between those associated of the company(i.e.factors determining economic risk)and those associated with financing the firm(i.e.factors determining financial risk).We then allow economic risk to be a determinant of financial policy in the structural framework of Leland and Toft(1996),or alternatively, in a reduced form model of financial leverage.An advantage of the structural model approach is that we are able to account for both the possibility of financial and operatingimplciations of

some factors(e.g.dividends),as well as the endogenous nature of the bankruptcy decision andfinancialpolicy in general.Our proxy for firm risk is the volantility if commonstock returns derived from calculating the standard deviation of daliyequity returns.Our proxies for econmic risk are designed to capture the essentialcharactersiticsof the firm’s operations and assets that determine the cash flow generating process for the firm.For example,firm size and age provide measures of line of –businessmaturity;tangible assets(plant,property,and equipment)serve as a proxy for the ‘hardness’of a firm’s assets;capital expenditures measure captial intensity as well as growth potential.Operatingprofitability and operatingprofit volatilityserve as measures of the timeliness and riskiness of cash flows.To understand how financial factors affect firm risk,we examinetotal debt,debtmaturity,dividend payouts,and holdings of cash and short-term investments.The primary resuit or our analysis is surpriing:factors determining economic risk for a typical company exlain the vast majority of the varation in equity volatility.Correspondingly,measures of implied financial leverage are much lower than observed debt ratios.Specifically, in our sample covering 1964-2008 average actual net financial(market)leverage is 1.50 compared to our estimates of between 1.03 and 1.11(depending on model specification and estimation technique).This suggests that firms may undertake other financial policise to manage financial risk and thus lower effective leverage to nearly negligible levels.These policies might include dynamically adjusting financial variables such as debt levels,debt maturity,or cash holdings(see,for example , Acharya,Almeida,and Campello,2007).In addition,many firms also utilize explicit financial risk management techniques such as the use of financial dervatives,contractual arrangements with investors(e.g.lines of credit,call provisions in debt contracts ,or contingencies in supplier contracts),spcial purpose vehicles(SPVs),or other alternative risk transfer techniques.The effects of our ecnomic risk factors on equity volatility are generally highly statiscally significant, with predicted size and age of the firm.This is intuitive since large and mature firms typically have more stable lines of business,which shoule be reflected in the volatility.This suggests that companties with higher and more stable operating cash flows are less likely to go bankrupt, and therefore are potentially less risky.Among economic risk variables,the effects of firm size ,prfit volatility,and dividend policy on equity volatility stand out.Unlike some previous studies,our careful treatment of the endogeneity of financial policy confirms that leveage increases total firm risk.Otherwise,fiancial risk factors are not reliably to total risk.Given the large literature on financial policy , it is no surprise that financial variables are , at least in part , determined by the econmic risks frims take.However, some of the specific findings are unexpected.For example , in a simple model of capital structure ,dividend payouts should increase financial leverage since they represent an outflow of cash from the firm(i.e.,increase net debt).We find that dividends are associated with lower risk.This suggests that paying dividends is not as much a product of financial policy as a characteristic of a firm’s operations(e.g.,a mature company with limited growth opportunities).We also estimate how

sensitivities to different risk factors have changed over time.Our result indicate that most relations are fairly stable.One exception is firm age which prior to 1983 tends to be positively related to risk and has since been consisitently negatively related to risk.This is related to findings by Brown and Kapadoa(2007)that recent trends in idiosyncratic risk are related to stock listings by younger and riskier firms.

第五篇：交通运输外文翻译外文文献

交通事故分析的可能性和局限性

S.Oppe 关键字：后果;目的;描述;限制;关注;事故分析;可能性

摘要：交通事故的统计数字，尤其国家一级的数据对监控和预测事故的发展，积极或消极检测事故的发展，以及对定义安全目标和评估工业安全特别有益。事故分析是应用非常有限的分析，是前瞻性分析和回顾性分析，能够对新开发的交通安全系统和特殊过程的安全措施进行评价。目前迫切需要一个将实时事故分析与研究相结合的行为。将自动检测和视频录制相结合的研究交通事故的科研论文会比较容易接受。这种类型的研究最终会对交通理念有个完善的认识。

1．简介

本文主要是基于个人的经验，研究有关交通安全、安全分析以及事故分析等在研究中的作用。由这些经验推导出的哲学思考就像通过研究和统计得出的实践观点。而这些调查数字已经在其他地方发表了。

在缺少直接观察的事故中，许多方法论问题的产生，导致不能直接测试对结果持续讨论。通过看事故视频来讨论是富有成效的。事实证明，用来解释事故的大部分有关信息就是事故中缺少的记录。深入研究还无法回忆起所有的必要的用来测试有关事故发生的假设数据。尤其是车-车相撞发生的车祸，这是在荷兰城市道路交叉口录制的视频，一辆从岔路驶来的汽车与主干路的汽车相撞，下列问题可以问：为什么汽车来自次干路上，突然加速后又几乎停止，撞上了在左侧主路的一辆汽车呢？为什么没有注意到正在驶来的车？是不是因为两车从右边驶来，司机因为前面的交叉为他们提供了可能性而斤斤计较？难道他向左看过，但他认为停在拐角处的绿色货车能让他停下来？当然，交通状况并不复杂。目前这个事故中没有骑自行车或行人在拥挤路口分散他的注意。如果停着的绿色车能够在五分钟内消失，这两辆车可能就不会相撞。在事故发生的相关条件下，几乎不可能观察下一个交通行为，因为交通事故是不可预见的。由于新的视频设备和自动检测事故设备的不断发展，如在收集数据方面不需要很高的成本就能变得越来越逼真。必要的增加数据类型也能更好的解释交通中存在的危险因素。关于事故分析的可能性和限制性的问题是不容易回答的，我们不能确切的分析交通事故。因为事故分析涵盖了每一个活动中的不同背景，并根据不同的信息来源范围来补充资料，特别是收集事故的数据，背景资料等，我们首先要看看在交通安全领域的活动周期然后再回答事故分析的可能性与限制。这些行为主要是与交通系统的安全管理有关，有些则是相关的研究活动。

应该用下面的步骤来加以区分： ——检测交通安全问题；

——描述问题和它的主要特征； ——分析其原因分析和改进建议； ——选择和执行安全措施； ——评价所采取的措施。

虽然这个周期可以由同一人或一群人做出来，而问题在每个阶段（政治/管理或科学）都有不同的背景。我们用事故分析来描述这一阶段。做这个决定是重要的。很多关于分析结果的方法的讨论由于忽视之间的区别而成为徒劳的。政治家或道路管理人员对道路的个别事故不是很留意。他们对事故的看法往往都是一视同仁，因为总的结果比整个事故中的每个人的因素重要。因此，每次事故看做一个个体，之间相互协调就会达成安全的结果。

研究人员研究事故发生时一连串事件中每个人的兴趣。希望从中得到关于每次事故的详细信息并能发现其发生的原因和有关的条件。政治家们希望只是因为细节决定行动。在最高一级事故总数减少。信息的主要来源是国家数据库及其统计学处理系统。对他来说，统计意外数字及其统计的波动来进行事故分析。这适用于事故分析中的交通安全领域。因此，我们将首先描述了事故的这些方面。2．事故的性质和它们的统计特性

事故基本概念是意外，不管是其发生的原因还是引起事故出现的过程。两个简单的假设通常是来描述交通事故的形成过程：

-事故发生的概率与以往发生的事故之间是独立；-事故发生在时间上是同性质的

如果这两个假设成立，那么事故是泊松分布。第一个假设与大多数的批判不符。事故是罕见的事件，因此不会受到以前事故的影响。在某些情况下，有一个直接的因果链（例如，大量的车开到一起）这一系列的事故被认为是一个个体事故但包含许多的车。这个假设并不适用于统计人员伤亡。伤亡人数往往与同一事故有关，因此，独立性假设不成立。第二个假设乍一看似乎不太容易理解。穿越空间或在不同地点发生的的事故同样具有可能性。然而，假设需要很长一段时间并且没有缓缴期。其性质是根据理论的假设。如果其短时间内能成立，那么它也适用于长时间，因为泊松分布变量的总和，即使他们的泊松率是不同的，但也属于泊松分布。对于这些时期的总和泊松率则等于为这些地方的泊松率的总和。假设与一个真正的情况相比较计数，无论是从一两个结果还是总情况来看都有一个基本情况比较符合。

例如，对比在一年中特定的一天例如下一天，下一个星期的一天发生的交通事故。如果条件是相同的（同一时间，交通情况相同，同样的天气条件等），那么由此产生的意外数字是相同的泊松过程的结果。这一假设可以通过估算进行测试的两个观测值的基础上（估计是两个值的平均值）的速度参数。概率理论能够

考虑到这两个观察值的平均，用于计算的平等假设的可能性。这是一个相当强大的统计过程。泊松假设是研究了很多次，来获得证据支持。它已经应用于许多情况，数的差异表明在安全性的差异然后确定是否发生意外。这一程序的主要目的是检测在安全分歧。这可能是一个时间上的差异，或不同的地方或不同的条件。这种差异可以指导改进的过程。由于主要关注的是，以减少意外的发生，这种分析可能导致对治疗中最有前途的领域。为这样一个测试应用程序的必要条件是，那意外的数字进行比较是大到足以证明存在的分歧。在许多地方情况下，一个应用程序是不可能的。事故黑点分析往往阻碍了这一限制，例如，如果应用这种测试，找出事故是否在特定的位置数是高于平均水平。该程序的描述，也可以使用，如果发生意外乃根据数的特点找到有前途的安全目标。不仅聚集，而且还与分类泊松假设成立，而意外数字可以相互测试的泊松假设的基础。这种测试是相当麻烦的，因为每个特定的情况下，每一个不同的泊松参数，即，对所有可能结果的概率必须计算应用测试。然后，泊松分布近似为正态分布，均值和方差等于泊松参数。一旦均值和方差的正态分布，给出了所有的测试可以改写了标准零均值和

方差的正态分布条件。没有任何更多的必要计算，但测试统计，需要利用表绘制。3.行车安全政策事故统计的应用

分析那些假设的基础上描述的测试程序的类型及其优点。这种应用最好的例子是为一个国家或地区进行超过一年的安全监测，用事故的总体数据（最终的特定类型，如死亡事故）与前几年的数据相比较。根据数年的事故序列，能够分析出它的发展趋势，并大致预测以后几年的事故数量。一旦建立了这样一种趋势，那么在误差范围内未来一年或几年都可以预见。从一个给定趋势的偏差也可以进行预测新的事件。最有名的是斯米德在1949年进行的分析。我们将讨论这个事故类型分析更详细的内容。

1、该测试应用推广到高阶分类。Foldvary和Lane（1974），在衡量强制佩戴安全带的效果，谁是最早应用于值的4路表高阶相互作用的总卡方分配的。

2、测试不局限于总体影响，但卡方值就可以分解模型内子假说。另外，在双向表，卡方总可以分解成零件表互动的作用。对1的优势。和2。比以前的情况是，这对许多相互关联的（子）表和相应的智广场卡方检验是由大量分析，取而代之的是一个一卡方的确切划分。

3、投入更多关注的是参数估计。例如，在卡方分割使人们有可能以测试有关行参数的线性或二次限制或趋势的不连续性。

4、分析的单位是从数到广义加权计数。这对于道路安全分析，那里一段时间，道路使用者的数量，地点或公里数的车辆往往是必要的修正有利。最后一个选项是没有发现在许多统计软件包。安徒生1977年给出了一个用于道路双向安全分析表的例子。工资保障运动的一个计算机程序。这一级没有说明事故原因分

析。它会尝试检测安全问题需要特别注意。所需的基本信息包括事故数字，来形容不安全总额，暴露的数据来计算风险，并找到一个高风险的情况下或（团体）道路使用者。

4.事故分析研究目的

交通安全的研究是有关的事故及其后果的发生。因此，人们可能会说，研究对象是意外。然而研究人员的兴趣较少集中在这个最后的结果本身，而是多在进程更多的结果（或不结果）的事故。因此，最好是把作为他的研究对象，在流量的重要事件。一个在交通意外的过程，结果是，该实际发生是由研究者未落观测研究的主要问题。

调查一宗交通意外，他将努力重建了间接来源的事件，如涉及的道路使用者，所提供的资料或目击者有关情况，车辆，道路和司机的特点。因此这不是科学独特的，也有一个间接的研究对象的研究更多的例子。但是，第二个困难是，该研究的对象不能被诱发。有系统的控制实验手段研究只对问题方面的可能，而不是问题本身。

间接观察和缺乏系统的控制组合使调查人员很难发现在什么情况下造成事故的因素。虽然研究人员主要是在事故处理领导有兴趣，他几乎完全信息的后果，它的产品，意外。此外，事故背景是复杂的。一般来说，可分为以下几个方面：

-考虑到交通系统，交通量和组成国家，道路使用者，他们的速度，天气条件下，路面情况，车辆，道路使用者和他们的相互作用的演习，意外可以或无法预防。

-由于发生事故，也对这样的速度和车辆质量的因素，大量的不同，碰撞角度，对道路使用者和他们的脆弱性，影响等位置的保护，伤害是严重或或多或少物质损失是多还是少可观。虽然这些方面不能独立研究从理论的角度看，它也从由此产生的结果的优势，区分交通情况有潜在危险的数字，是由有一个意外的可能性，在这种潜在的危险局势，给定一个特定事故。

这个概念框架是对风险的关于个别道路使用者，以及上级的决定控制器的决定制定的一般基础。在风险的数学公式，我们需要一个明确的概率空间的介绍，基本事件（的情况），可能导致事故组成，每个类型的事件的概率，最终收在一次事故中，最后的具体成果，损失，鉴于事故的类型。

另一种方法是看事故特征组合，然后找出关键因素。这种类型的事故分析是通过分析事故的共组或子群来开展。事故本身是一个研究的单位，但也要研究道路因素：道路位置，道路设计（如一个弯道）等。

原文出处：SWOV institute for road safety research Leidschendam（会议记录），记录者，S.Oppe.POSSIBILITIES AND LIMITATIONS OF ACCIDENT

ANALYSIS

S.Oppe Keyword：Consequences;purposes;describe;Limitations;concerned;Accident Analysis;possibilities Abstraet：Accident statistics, especially collected at a national level are particularly useful for the description, monitoring and prognosis of accident developments, the detection of positive and negative safety developments, the definition of safety targets and the(product)evaluation of long term and large scale safety measures.The application of accident analysis is strongly limited for problem analysis, prospective and retrospective safety analysis on newly developed traffic systems or safety measures, as well as for(process)evaluation of special short term and small scale safety measures.There is an urgent need for the analysis of accidents in real time, in combination with background behavioural research.Automatic incident detection, combined with video recording of accidents may soon result in financially acceptable research.This type of research may eventually lead to a better understanding of the concept of risk in traffic and to well-established theories.1.Introduction.This paper is primarily based on personal experience concerning traffic safety, safety research and the role of accidents analysis in this research.These experiences resulted in rather philosophical opinions as well as more practical viewpoints on research methodology and statistical analysis.A number of these findings are published already elsewhere.From this lack of direct observation of accidents, a number of methodological problems arise, leading to continuous discussions about the interpretation of findings that cannot be tested directly.For a fruitful discussion of these methodological problems it is very informative to look at a real accident on video.It then turns out that most of the relevant information used to explain the accident will be missing in the accident record.In-depth studies also cannot recollect all the data that is necessary in order to test hypotheses about the occurrence of the accident.For a particular car-car accident, that was recorded on video at an urban intersection in the Netherlands, between a car coming from a minor road, colliding with a car on the major road, the following questions could be asked:Why did the driver of the car coming from the minor road, suddenly accelerate after coming almost to a stop and hit the side of the car from the left at the main road? Why was the approaching car not noticed? Was it because the driver was preoccupied with the two cars coming from the right and the gap before them that offered him the possibility to cross? Did he look left before, but was his view possibly blocked by the green van parked at the corner? Certainly the traffic situation was not complicated.At the moment of the accident there were no 5

bicyclists or pedestrians present to distract his attention at the regularly overcrowded intersection.The parked green van disappeared within five minutes, the two other cars that may have been important left without a trace.It is hardly possible to observe traffic behaviour under the most relevant condition of an accident occurring, because accidents are very rare events, given the large number of trips.Given the new video equipment and the recent developments in automatic incident and accident detection, it becomes more and more realistic to collect such data at not too high costs.Additional to this type of data that is most essential for a good understanding of the risk increasing factors in traffic, it also important to look at normal traffic behaviour as a reference base.The question about the possibilities and limitations of accident analysis is not lightly answered.We cannot speak unambiguously about accident analysis.Accident analysis covers a whole range of activities, each originating from a different background and based on different sources of information: national data banks, additional information from other sources, specially collected accident data, behavioural background data etc.To answer the question about the possibilities and limitations, we first have to look at the cycle of activities in the area of traffic safety.Some of these activities are mainly concerned with the safety management of the traffic system, some others are primarily research activities.The following steps should be distinguished:description of the problem and its main characteristics;selection and implementation of safety measures;the probability of an accident to occur is independent from the occurrence of previous accidents;-the occurrence of accidents is homogeneous in time.If these two assumptions hold, then accidents are Poisson distributed.The first assumption does not meet much criticism.Accidents are rare events and therefore not easily influenced by previous accidents.In some cases where there is a direct causal chain(e.g., when a number of cars run into each other)the series of accidents may be regarded as one complicated accident with many cars involved.The assumption does not apply to casualties.Casualties are often related to the same accident and therefore the independency assumption does not hold.The second assumption seems less obvious at first sight.The occurrence of accidents through time or on different locations are not equally likely.However, the assumption need not hold over long time periods.It is a rather theoretical assumption in its nature.If it holds for short periods of time, then it also holds for long periods, because the sum of Poisson distributed variables, even if their Poisson rates are different, is also Poisson distributed.The Poisson rate for the sum of these periods is then equal to the sum of the Poisson rates for these parts.The assumption that really counts for a comparison of(composite)situations, is whether two outcomes from an aggregation of situations in time and/or space, have a comparable mix of basic situations.E.g., the comparison of the number of accidents on one particular day of the year, as compared to another day(the next day, or the same day of the next week etc.).If the conditions are assumed to be the same(same duration, same mix of traffic and situations, same weather conditions etc.)then the resulting numbers of accidents are the outcomes of the same Poisson process.This assumption can be tested by estimating the rate parameter on the basis of the two observed values(the estimate being the average of the two values).Probability theory can be used to compute the likelihood of the equality assumption, given the two observations and their mean.This statistical procedure is rather powerful.The Poisson assumption is investigated many times and turns out to be supported by a vast body of empirical evidence.It has been applied in numerous situations to find out whether differences in observed numbers of accidents suggest real differences in safety.The main purpose of this procedure is to detect differences in safety.This may be a difference over time, or between different places or between different conditions.Such differences may guide the process of improvement.Because the main concern is to reduce the 7

number of accidents, such an analysis may lead to the most promising areas for treatment.A necessary condition for the application of such a test is, that the numbers of accidents to be compared are large enough to show existing differences.In many local cases an application is not possible.Accident black-spot analysis is often hindered by this limitation, e.g., if such a test is applied to find out whether the number of accidents at a particular location is higher than average.The procedure described can also be used if the accidents are classified according to a number of characteristics to find promising safety targets.Not only with aggregation, but also with disaggregation the Poisson assumption holds, and the accident numbers can be tested against each other on the basis of the Poisson assumptions.Such a test is rather cumbersome, because for each particular case, i.e.for each different Poisson parameter, the probabilities for all possible outcomes must be computed to apply the test.In practice, this is not necessary when the numbers are large.Then the Poisson distribution can be approximated by a Normal distribution, with mean and variance equal to the Poisson parameter.Once the mean value and the variance of a Normal distribution are given, all tests can be rephrased in terms of the standard Normal distribution with zero mean and variance one.No computations are necessary any more, but test statistics can be drawn from tables.3.The use of accident statistics for traffic safety policy.The testing procedure described has its merits for those types of analysis that are based on the assumptions mentioned.The best example of such an application is the monitoring of safety for a country or region over a year, using the total number of accidents(eventually of a particular type, such as fatal accidents), in order to compare this number with the outcome of the year before.If sequences of accidents are given over several years, then trends in the developments can be detected and accident numbers predicted for following years.Once such a trend is established, then the value for the next year or years can be predicted, together with its error bounds.Deviations from a given trend can also be tested afterwards, and new actions planned.The most famous one is carried out by Smeed 1949.We will discuss this type of accident analysis in more detail later.1.The application of the Chi-square test for interaction is generalised to higher order classifications.Foldvary and Lane(1974), in measuring the effect of compulsory wearing of seat belts, were among the first who applied the partitioning of the total Chi-square in values for the higher order interactions of four-way tables.2.Tests are not restricted to overall effects, but Chi-square values can be decomposed regarding sub-hypotheses within the model.Also in the two-way table, the total Chisquare can be decomposed into interaction effects of part tables.The advantage of 1.and 2.over previous situations is, that large numbers of Chi-square tests on many interrelated(sub)tables and

corresponding Chi-squares were replaced by one analysis with an exact portioning of one Chi-square.3.More attention is put to parameter estimation.E.g., the partitioning of the Chi-square made it possible to test for linear or quadratic restraints on the row-parameters or for discontinuities in trends.4.The unit of analysis is generalised from counts to weighted counts.This is especially advantageous for road safety analyses, where corrections for period of time, number of road users, number of locations or number of vehicle kilometres is often necessary.The last option is not found in many statistical packages.Andersen 1977 gives an example for road safety analysis in a two-way table.A computer programme WPM, developed for this type of analysis of multi-way tables, is available at SWOV(see: De Leeuw and Oppe 1976).The accident analysis at this level is not explanatory.It tries to detect safety problems that need special attention.The basic information needed consists of accident numbers, to describe the total amount of unsafety, and exposure data to calculate risks and to find situations or(groups of)road users with a high level of risk.4.Accident analysis for research purposes.Traffic safety research is concerned with the occurrence of accidents and their consequences.Therefore, one might say that the object of research is the accident.The researchers interest however is less focused at this final outcome itself, but much more at the process that results(or does not result)in accidents.Therefore, it is better to regard the critical event in traffic as his object of study.One of the major problems in the study of the traffic process that results in accidents is, that the actual occurrence is hardly ever observed by the researcher.Investigating a traffic accident, he will try to reconstruct the event from indirect sources such as the information given by the road users involved, or by eye-witnesses, about the circumstances, the characteristics of the vehicles, the road and the drivers.As such this is not unique in science, there are more examples of an indirect study of the object of research.However, a second difficulty is, that the object of research cannot be evoked.Systematic research by means of controlled experiments is only possible for aspects of the problem, not for the problem itself.The combination of indirect observation and lack of systematic control make it very difficult for the investigator to detect which factors, under what circumstances cause an accident.Although the researcher is primarily interested in the process leading to accidents, he has almost exclusively information about the consequences, the product of it, the accident.Furthermore, the context of accidents is complicated.Generally speaking, the following aspects can be distinguished: Given an accident, also depending on a large number of factors, such as the speed and mass of vehicles, the collision angle, the protection of road users and their vulnerability, the location of impact etc., injuries are more or less severe or the material damage is more or less substantial.Although these aspects cannot be studied independently, from a theoretical point of view it has advantages to distinguish the number of situations in traffic that are potentially dangerous, from the probability of having an accident given such a potentially dangerous situation and also from the resulting outcome, given a particular accident.This conceptual framework is the general basis for the formulation of risk regarding the decisions of individual road users as well as the decisions of controllers at higher levels.In the mathematical formulation of risk we need an explicit description of our probability space, consisting of the elementary events(the situations)that may result in accidents, the probability for each type of event to end up in an accident, and finally the particular outcome, the loss, given that type of accident.A different approach is to look at combinations of accident characteristics, to find critical factors.This type of analysis may be carried out at the total group of accidents or at subgroups.The accident itself may be the unit of research, but also a road, a road location, a road design(e.g.a roundabout)etc.