试论企业的环境成本管理

近年来随着人们环保意识的增强,企业对环境成本的管理日趋重视。本文从环境成本的内涵入手,阐述了环境成本的管理指导思想,并提出了环境成本管理的方法。     

Local polynomial estimation of Poisson intensities in the presence of reporting delays

Summary.  The system for monitoring suicides in Hong Kong has considerable delays in reporting as the cause of death needs to be determined by a coroner's investigation. However, timely estimates of suicide rates are desirable to assist in the formulation of public health policies. This motivated us to develop a non-parametric procedure to estimate the intensity function of a Poisson process in the presence of reporting delays. We give closed form estimators of the Poisson intensity and the delay distribution, conduct simulation studies to evaluate the method proposed and derive their asymptotic properties. The method proposed is applied to estimate the intensity of suicide in Hong Kong.     

世界教育信息化发展及其经验

教育信息化是战后教育发展的最重要发展方向之一。世界教育信息化的发展经历了发端、进一步推进和迅速高涨的发展时期;在每一个阶段各国推进教育信息化的政策、措施和特点等方面都呈现出一些独自的特征。总结世界各国推进教育信息化的经验对我国教育信息化的发展具有重要的启发意义。     

Bayesian validation assessment of multivariate computational models

Multivariate model validation is a complex decision-making problem involving comparison of multiple correlated quantities, based upon the available information and prior knowledge. This paper presents a Bayesian risk-based decision method for validation assessment of multivariate predictive models under uncertainty. A generalized likelihood ratio is derived as a quantitative validation metric based on Bayes’ theorem and Gaussian distribution assumption of errors between validation data and model prediction. The multivariate model is then assessed based on the comparison of the likelihood ratio with a Bayesian decision threshold, a function of the decision costs and prior of each hypothesis. The probability density function of the likelihood ratio is constructed using the statistics of multiple response quantities and Monte Carlo simulation. The proposed methodology is implemented in the validation of a transient heat conduction model, using a multivariate data set from experiments. The Bayesian methodology provides a quantitative approach to facilitate rational decisions in multivariate model assessment under uncertainty.     

Sampling Returns for Realized Variance Calculations: Tick Time or Transaction Time?

This article introduces a new model for transaction prices in the presence of market microstructure noise in order to study the properties of the price process on two different time scales, namely, transaction time where prices are sampled with every transaction and tick time where prices are sampled with every price change. Both sampling schemes have been used in the literature on realized variance, but a formal investigation into their properties has been lacking. Our empirical and theoretical results indicate that the return dynamics in transaction time are very different from those in tick time and the choice of sampling scheme can therefore have an important impact on the properties of realized variance. For RV we find that tick time sampling is superior to transaction time sampling in terms of mean-squared-error, especially when the level of noise, number of ticks, or the arrival frequency of efficient price moves is low. Importantly, we show that while the microstructure noise may appear close to IID in transaction time, in tick time it is highly dependent. As a result, bias correction procedures that rely on the noise being independent, can fail in tick time and are better implemented in transaction time.     

谁开创了贝叶斯学派？——对拉普拉斯1774年一篇文章的回顾

1764年,贝叶斯的遗作《机遇理论中一个问题的解》，是当今统计学界贝叶斯学派的开山之作，然而直到20世纪，贝叶斯的文章却并未对后世贝叶斯学派的发展产生重大影响。事实上，真正促使贝叶斯的思想在科学界得到广泛传播的关键人物是大科学家拉普拉斯。1774年，拉普拉斯发表的关于贝叶斯理论的里程碑式的文章，使现代读者充分认识到拉普拉斯对贝叶斯学派发展所起的巨大作用，并从拉普拉斯的思想中获得了有益的新知。     

Bayesian analysis of elapsed times in continuous‐time Markov chains

The authors consider Bayesian analysis for continuous‐time Markov chain models based on a conditional reference prior. For such models, inference of the elapsed time between chain observations depends heavily on the rate of decay of the prior as the elapsed time increases. Moreover, improper priors on the elapsed time may lead to improper posterior distributions. In addition, an infinitesimal rate matrix also characterizes this class of models. Experts often have good prior knowledge about the parameters of this matrix. The authors show that the use of a proper prior for the rate matrix parameters together with the conditional reference prior for the elapsed time yields a proper posterior distribution. The authors also demonstrate that, when compared to analyses based on priors previously proposed in the literature, a Bayesian analysis on the elapsed time based on the conditional reference prior possesses better frequentist properties. The type of prior thus represents a better default prior choice for estimation software.     

上市公司综合评价研究

客观合理地评价上市公司,是投资者、上市公司以及监管机构都非常关注的问题,也是规范发展证券市场的一个重要方面。基于平衡记分卡的原理,提出了我国上市公司的评价指标体系。财务层面的评价采用因子分析法;客户层面、内部层面、学习与创新层面以及综合评价,则是根据模糊三角数的概念构造判断矩阵,利用模糊三角数比较大小的原理进行排序。     

激活沉淀资源 加快贵州发展

目前我国社会中存在生产要素闲置状况 ,而且这种状况有加剧的趋势。党的十六大提出全新的价值理论 ,并在这一理论指导下解决该类问题 :提出激活闲置资源 ,加快经济社会稳定发展的建议和措施     

经济预测中的Monte Carlo模拟及方差控制——以国际石油价格预测为例

从MDnte Carlo模拟的实现过程入手，首先通过对Monte Carlo方法原理的阐述来介绍该种方法。进一步结合具体的实例通过计算机进行模拟来解释Monte Carlo方法的具体实现过程。重点讨论在选择合理的数据生成过程的前提下，如何在Monte Carlo方法中减少模拟方差，从而提高估计精度，更好地应用这种方法来进行经济预测。