Benchmark Analysis: Shopping with Proper Confidence

We discuss the issue of using benchmark doses for quantifying (excess) risk associated with exposure to environmental hazards. The paradigm of low-dose risk estimation in dose-response modeling is used as the primary application scenario. Emphasis is placed on making simultaneous inferences on benchmark doses when data are in the form of proportions, although the concepts translate easily to other forms of outcome data.     

衍生金融工具风险:种类、成因与控制

衍生金融工具的风险问题已经引起了各国经济界和管理当局的广泛关注。本文将衍生金融工具的风险概括为市场风险、信用风险、流动性风险、营运风险和法律风险五类 ,探讨了各种风险的成因 ,并提出了防范和控制对策     

风险投资家的双重逆向选择风险规避机制

风险投资过程中,由于信息的不对称,投资者与风险投资家之间、风险投资家与风险企业家之间存在着双重逆向选择风险。在融资阶段的信号传递机制中,作为代理人的风险投资家,选择融资计划书信号,向作为委托人的投资者传递其能力信号,投资者据此修正自己的先验概率,然后根据后验概率,与风险投资家签定合同规避风险;在投资阶段的信息甄别机制中,作为中间委托人的风险投资家先提供合同,这时唯一可能是分离均衡,即不同类型的风险企业家选择不同的合同规避风险。     

虚拟环境下产品装配设计的交互改进方法

装配设计是产品制造过程中的一个重要环节 .与传统的 CAD软件不同 ,本文论述的交互方式下改进的装配设计方法 ,借助于先进的计算机虚拟技术 ,支持自顶向下的设计思想 .继而构造了产品装配设计的环境     

政府经济职能创新的路径选择

当前 ,在政府经济职能重新定位过程中 ,我们应特别关注以下三个问题 :产权保护制度、限政政府模式、社会风险承受能力。建立产权保护制度是政府经济职能重新定位的出发点 ;构建限政政府模式是社会主义市场经济的逻辑要求 ;以改革促稳定、建立良好的社会保障制度 ,从而提高社会风险承受能力 ,是为改革提供稳定社会基础的必经之途。按照这三方面的要求来创新政府经济职能 ,就可以使政府的经济职能基本上能够适应市场经济体制对它的客观要求     

试论企业经营中的委托——代理关系与激励机制设计

企业经营中的委托—代理关系和激励机制问题显然是存在若干冲突理论和观点 的复杂课题，本文通过一个简单的数理模型对这一问题进行了理论上的阐释，同时也给出了现 阶段解决问题的一般思路。     

水务工程BOT项目与风险规避初探

国家卫生部2001年6月7日颁布的《生活饮用水水质卫生规范》和国民及政府对环境保护的要求标准,给进入21世纪的中国水务工程市场带来了喜人的市场机遇,但是也存在着巨大的融资困难。BOT模式是解决融资困难的一条极其有效的途径。内资民营企业的加入将成为中国BOT水务项目的主体。通过实例对BOT水务工程存在的风险以及规避方法进行了初步探讨。     

论网络空间的社会风险

互联网的崛起为人们的日常生活、学习和工作带来了诸多便利,然而,作为一种全新的信息技术范式,互联网也给人类社会生活带来了许多新的风险。文章分析和论述了网络风险的各种表现形式、网络风险的实质以及网络风险产生的根源,以期为网络风险管理提供借鉴。     

The Role of Cancer Risk in the Regulation of Industrial Pollution

The extent of carcinogen regulation under existing U.S. environmental statutes is assessed by developing measures of the scope and stringency of regulation. While concern about cancer risk has played an important political role in obtaining support for pollution control programs, it has not provided the predominant rationale for most regulatory actions taken to date. Less than 20% of all standards established to limit concentrations of chemicals in various media address carcinogens. Restrictions on chemical use are more frequently based on concerns about noncancer human health or ecological effects. Of the chemicals in commercial use which have been identified as potential human carcinogens on the basis of rodent bioassays, only a small proportion are regulated. There is an inverse relationship between the scope of regulatory coverage and the stringency of regulatory requirements: the largest percentages of identified carcinogens are affected by the least stringent requirements, such as information disclosure. Standards based on de minimis cancer risk levels have been established for only 10% of identified carcinogens and are restricted to one medium: water. Complete bans on use have affected very few chemicals. The general role that carcinogenicity now plays in the regulatory process is not dramatically different from that of other adverse human health effects: if a substance is identified as a hazard, it may eventually be subject to economically achievable and technically feasible restrictions.     

Physiologically Based Liver Modeling and Risk Assessment

Because of the inherent complexity of biological systems, there is often a choice between a number of apparently equally applicable physiologically based models to describe uptake and metabolism processes in toxicology or risk assessment. These models may fit the particular data sets of interest equally well, but may give quite different parameter estimates or predictions under different (extrapolated) conditions. Such competing models can be discriminated by a number of methods, including potential refutation by means of strategic experiments, and their ability to suitably incorporate all relevant physiological processes. For illustration, three currently used models for steady-state hepatic elimination--the venous equilibration model, the parallel tube model, and the distributed sinusoidal perfusion model--are reviewed and compared with particular reference to their application in the area of risk assessment. The ability of each of the models to describe and incorporate such physiological processes as protein binding, precursor-metabolite relations and hepatic zones of elimination, capillary recruitment, capillary heterogeneity, and intrahepatic shunting is discussed. Differences between the models in hepatic parameter estimation, extrapolation to different conditions, and interspecies scaling are discussed, and criteria for choosing one model over the others are presented. In this case, the distributed model provides the most general framework for describing physiological processes taking place in the liver, and has so far not been experimentally refuted, as have the other two models. These simpler models may, however, provide useful bounds on parameter estimates and on extrapolations and risk assessments.