Estimation of Hazard, Density and Survivor Functions for Randomly Censored Data

Maximum likelihood estimation and goodness-of-fit techniques are used within a competing risks framework to obtain maximum likelihood estimates of hazard, density, and survivor functions for randomly right-censored variables. Goodness-of- fit techniques are used to fit distributions to the crude lifetimes, which are used to obtain an estimate of the hazard function, which, in turn, is used to construct the survivor and density functions of the net lifetime of the variable of interest. If only one of the crude lifetimes can be adequately characterized by a parametric model, then semi-parametric estimates may be obtained using a maximum likelihood estimate of one crude lifetime and the empirical distribution function of the other. Simulation studies show that the survivor function estimates from crude lifetimes compare favourably with those given by the product-limit estimator when crude lifetimes are chosen correctly. Other advantages are discussed.     

Deconvolution with supersmooth distributions

Nonparametric deconvolution problems require one to recover an unknown density when the data are contaminated with errors. Optimal global rates of convergence are found under the weighted L_p-loss (1 ≤ p ≤ ∞). It appears that the optimal rates of convergence are extremely low for supersmooth error distributions. To resolve this difficulty, we examine how high the noise level can be for deconvolution to be feasible, and for the deconvolution estimate to be as good as the ordinary density estimate. It is shown that if the noise level is not too high, nonparametric Gaussian deconvolution can still be practical. Several simulation studies are also presented.     

金融期权定价模型与金融风险管理

金融期货是一种具有独特功能的非常重要的衍生金融工具 ,对规避金融风险有重要意义 ,其作为一种金融资产表现为一种特定的权利。B -S期权模型开创性地表达了这种期权定价理论 ,二项式模型则将各种金融期权定价模型推向简化和实用化。     

对我国即将推出"股指期货"的思考

中国加入WTO后，中国的金融业正面临着巨大的挑战。金 融市场的国际化趋势给中国的证券市场提出了更高的要求，单一的投资工具已远远不能满足 投资者的需要。为了更好地与国际接轨，参与国际竞争，中国引入创新的金融衍生工具势在 必行。本文就开发中国股指期货的必要性及由此可能产生的问题提出见解。     

农户种植业风险及其认知比较研究

通过对浙江、上海、山东、湖北和安徽五个不同地区660户农户实地访问调查资料的分析发现:目前我国农户从事种植业生产经营的风险主要来源于气候等自然因素、农产品市场价格和农业生产资料价格;农户更关注农产品产量而非市场价格波动;在地区和作物层面上,具有不同生产特征和家庭特征的农户对种植业生产经营风险的认知具有一定的差异性;目前农户弱化种植业风险主要倾向于依靠自身的力量而较少依靠农业保险、农业组织及政府等外部力量。政府需要从完善信息发布体系、加强对农资市场管理、促进农村合作经济组织及农业保险的发展等方面入手,提高农户弱化生产经营风险的能力。     

对建立我国外资银行风险防范法律机制的探讨

介绍了外资银行风险防范的法律机制的具体内容,围绕风险监管指出金融宏观调控法律机制、外资银行风险监管法律机制、外资银行风险监管国际合作法律机制三者之间的关系。     

Intuitive Toxicology: Expert and Lay Judgments of Chemical Risks

Human beings have always been intuitive toxicologists, relying on their senses of sight, taste, and smell to detect harmful or unsafe food, water, and air. As we have come to recognize that our senses are not adequate to assess the dangers inherent in exposure to a chemical substance, we have created the sciences of toxicology and risk assessment to perform this function. Yet despite this great effort to overcome the limitations of intuitive toxicology, it has become evident that even our best scientific methods still depend heavily on extrapolations and judgments in order to infer human health risks from animal data. Many observers have acknowledged the inherent subjectivity in the assessment of chemical risks and have indicated a need to examine the subjective or intuitive elements of expert and lay risk judgments. We have begun such an examination by surveying members of the Society of Toxicology and the lay public about basic toxicological concepts, assumptions, and interpretations. Our results demonstrate large differences between toxicologists and laypeople, as well as differences between toxicologists working in industry, academia, and government. In addition, we find that toxicologists are sharply divided in their opinions about the ability to predict a chemical's effect on human health on the basis of animal studies. We argue that these results place the problems of risk communication in a new light. Although the survey identifies misconceptions that experts should clarify for the public, it also suggests that controversies over chemical risks may be fueled as much by limitations of the science of risk assessment and disagreements among experts as by public misconceptions.     

企业战略联盟风险防范体系的架构研究

在对企业战略联盟存在的风险及规避措施进行理论透析的基础上,给出了企业战略联盟伙伴选择机制的权值排序模型。提出了企业战略联盟的3种风险防范整合架构,并论述了三者之间的相关关系。最后通过实例对企业战略联盟伙伴选择机制的权值排序模型和风险防范整合体系进行了验证。     

业务外包风险分析与控制

结合现代企业理论中的交易费用理论和“委托-代理”理论,对业务外包风险进行了深入的剖析,详细分析了外包决策和执行两个阶段的风险,并提出了相应的风险控制策略。     

论概率安全评价中的组织风险因素

核电站组织风险已经成为核电站安全运行重要的影响因素,在概率安全评价中考虑组织风险因素是核电安全研究的重要课题。文章在建立组织风险因素与PSA之间转换的概念框架的基础上,对组织风险因素进行分类。分类后的组织风险因素受人员行为形成因子的影响,其影响在人因可靠性分析中进行分析。计算和评估这些人员行为形成因子对于事故后操纵员的影响可以计算组织因素对核电站安全的影响。