现货价格和需求关联时期权组合合约模式下采购风险管理策略

在现货价格和客户端需求关联的情形下,本文引用期权组合合约建立现货市场供应量有限时的两阶段采购风险管理模型,以期最大化零售商的期望收益。文中先用逆向归纳法列出零售商第二阶段的最优策略,采用标准扰动定理得出有效合约应满足的最优性条件,并将原模型转化为单调的最短路径问题,应用动态规划求解最优的采购策略。最后用算例分析了现货价格与需求的相关系数及现货市场的供应量对最优策略的影响,发现当供应量一定时,各有效合约的最优预订量及有效合约的总预订量都随着相关系数的增大而提高,并且有效合约受相关系数的影响大小取决于合约的灵活性;并且,当相关系数一定时,有效合约的总预订量及执行价格最低的有效合约的最优预订量都随着供应量的增加而单调减少。     

Discount Rates in Risk Versus Money and Money Versus Money Tradeoffs

We use data from a survey of residents of five Italian cities conducted in late spring 2004 to estimate the discount rates implicit in (1) money versus future risk reductions and (2) money versus money tradeoffs. We find that the mean personal discount rate is 0.3-1.7% in (1) and 8.7% in (2). The latter is lower than the discount rates estimated in comparable situations in many recent studies, greater than market interest rates in Italy at the time, and exhibits modest variation with age and gender. The discount rate implicit in money versus risk tradeoffs is within the range of estimates from studies in the United States and Europe, and does not depend on observable individual characteristics. We use split samples to investigate whether a completely abstract risk reduction - one where the risk reduction delivery has been stripped of all specifics, so that respondents should focus on the risks without being distracted by details - results in WTP and discount figures comparable to those from an identified delivery mechanism (a medical test). We find that while WTP for an immediate risk reduction is 42-73% higher with the abstract risk reduction, the discount rate in the money versus risk tradeoffs and the variance of the error term in the WTP equation are the same across the two variants of the questionnaire.     

公司治理、控制权性质与审计定价

借鉴Simunic的审计定价模型,构建关于审计定价影响因素的多元线性回归方程,并以沪深两市上市公司2007年数据为研究对象,对股权结构、公司治理与审计定价之间的关系进行实证检验.研究结果表明,总体而言,公司治理因素对中国上市公司审计定价的解释力有限,说明中国会计师事务所在决定审计收费时对被审计单位的公司治理因素考虑较少.具体而言,终极控制人为政府的上市公司审计费用较低,股权集中度、管理层持股比例与审计定价之间大体上呈U型关系,即股权适度集中和管理层适度持股最有利于降低审计定价,进一步的研究发现,管理层持股比例与审计定价的U型关系仅存在于非国有控股公司样本中.研究还发现,中国会计师事务所在确定审计费用时会结合公司控制权的性质考虑风险因素时审计定价的影响.     

企业IT能力系统动态演变的分析模型研究

揭示企业IT能力的演变规律,有助于把握影响IT能力系统的关键因素,从而提高企业信息系统的应用效果。本文以系统观为基础,依据协同学理论,讨论了企业IT能力系统的概念及其构成,探讨了企业IT能力系统的协同特征,提出了企业IT能力成熟度作为企业IT能力系统序参量的五种状态特征,并建立了企业IT能力系统的序参量方程,最后构造了该系统动态演化机制理论模型。     

基于重大偏差标准的软件项目工作量管理方法研究

为有效管理软件项目工作量,本文研究了一个基于重大偏差标准的软件项目工作量管理模型。该模型利用过程控制的原理和数理统计的方法,提出依据重大偏差标准和风险储备时间对软件项目进行动态控制,并介绍了风险储备时间与重大偏差标准的定量设置方法。该模型涵盖了从风险储备时间的确定,到重大偏差标准的提出,再根据风险储备时间和重大偏差标准进行监控的整个过程。为提高软件项目管理精度,保证项目在可接受的偏差范围内顺利完成打下坚实的基础。     

基于ODR-ADASYN-SVM的极端金融风险预警研究

针对合成少数类过采样(synthetic minority over-sampling technique,SMOTE)方法在提升支持向量机(support vector machine,SVM)的非均衡样本学习能力中出现的过拟合(over fitting),引入自适应合成抽样方法(adaptive synthetic sampling approach,ADASYN)和逐级优化递减欠采样方法(optimization of decreasing reduction,ODR)分别克服SMOTE在生成新样本中的盲目性和在处理对象上的局限性,进而与SVM相结合,构造出改进SVM,即ODR-ADASYN-SVM模型来预测中国极端金融风险;最后运用T检验对各模型预测精度的差异性进行显著性检验以及对各模型的预测稳定性进行评价.实证结果表明,ODR-ADASYN-SVM模型不仅能够显著地提升SVM的非均衡样本学习能力,同时也能够有效地克服SMOTE的过拟合,从而展示出优越的极端金融风险预测性能.     

Decision Analysis and Risk Management Decision Making: Issues and Methods

This paper provides an overview of decision analysis and its use in risk management decision making. The paper discusses the distinctive characteristics of decision analysis and compares these characteristics with those of its principal alternative—cost–benefit analysis. The paper also discusses each of the steps in a decision analysis and the strengths and limitations of the method.     

股票市场的极值风险测度及后验分析研究

通过对上证综指和世界股市若干重要指数的实证研究发现,无论是在成熟资本市场还是新兴资本市场当中,极值理论(EVT)及其工具都能更加准确地刻画实际市场的极端波动和风险状况.详细说明了不同收益分布假定下风险价值(VaR)的计算方法及其后验分析(Back-testing)过程,证明了与非条件和条件正态分布以及条件t分布等主流金融理论的收益分布假定相比,条件EVT分布在测度极端市场风险时所表现出的优越性,同时说明了在不同概率水平下各种收益分布假定的精确度和适用范围.     

Principles of Good Practice for the Use of Monte Carlo Techniques in Human Health and Ecological Risk Assessments

We propose 14 principles of good practice to assist people in performing and reviewing probabilistic or Monte Carlo risk assessments, especially in the context of the federal and state statutes concerning chemicals in the environment. Monte Carlo risk assessments for hazardous waste sites that follow these principles will be easier to understand, will explicitly distinguish assumptions from data, and will consider and quantify effects that could otherwise lead to misinterpretation of the results. The proposed principles are neither mutually exclusive nor collectively exhaustive. We think and hope that these principles will evolve as new ideas arise and come into practice.     

具有模糊收益的项目投资组合优化方法

基于可能性理论,研究了投资项目具有模糊收益的多项目投资组合的决策问题。在假设投资项目各年净现金流为三角模糊数的条件下,运用可能性均值和方差,建立了基于现值指数法的单投资项目模糊收益指标和模糊风险评价指标,同时,在此基础上建立了基于模糊可能性均值与方差的多项目投资组合优化模型,提出了最优项目投资组合的算法。最后,给出实际算例说明了方法的可行性和有效性。