Estimation of the marginal expected shortfall under asymptotic independence

We study the asymptotic behavior of the marginal expected shortfall when the two random variables are asymptotic independent but positively associated, which is modeled by the so-called tail dependent coefficient. We construct an estimator of the marginal expected shortfall, which is shown to be asymptotically normal. The finite sample performance of the estimator is investigated in a small simulation study. The method is also applied to estimate the expected amount of rainfall at a weather station given that there is a once every 100 years rainfall at another weather station nearby.     

开设化学设计性实验的探索与实践

阐述开设设计性实验的意义,并在实践的基础上,给出了开设化学设计性实验的方案,总结了开设设计性实验的体会。     

论阜新经济发展的外向性

文章从市场化的程度、贸易和经济的发展、开放梯度战略以及区域经济布局这四个方面剖析了阜新与经济发达地区的巨大差距及产生差距的原因,阐述了阜新的经济转型、产业结构调整及市场化发育与外向经济的依存关系,特别是从引进项目的基础工作、制定相关优惠政策及提高法律意识等方面,指明了阜新进一步对外开放需要解决和注意的问题。     

几种药剂对石榴“麻皮“病的防治研究

2002～2003年,在会理县彰冠乡和海潮乡,对石榴“麻皮”病进行了化学防治试验,试验结果表明:大生M-45、信生交替使用;春雨一号、达柯宁、阿米西达交替使用防效最好。     

Diagnostics for dependence within time series extremes

Summary. The analysis of extreme values within a stationary time series entails various assumptions concerning its long- and short-range dependence. We present a range of new diagnostic tools for assessing whether these assumptions are appropriate and for identifying structure within extreme events. These tools are based on tail characteristics of joint survivor functions but can be implemented by using existing estimation methods for extremes of univariate independent and identically distributed variables. Our diagnostic aids are illustrated through theoretical examples, simulation studies and by application to rainfall and exchange rate data. On the basis of these diagnostics we can explain characteristics that are found in the observed extreme events of these series and also gain insight into the properties of events that are more extreme than those observed.     

低浓度三分子反应模型双曲型反应－扩散方程的稳定性与化学振荡

考虑浓度扩散和扩散流随时间的变化，得到低浓度三分子反应模型的双曲型反应－扩散方程；讨论了方程的稳定性及存在行波解的条件，得到了化学振荡的色散关系和相速度．     

Towards Enhancement of the Economy of a Thermal Power Generating System through Prediction of Plant Efficiency

The plant ‘Heat Rate’ (HR) is a measure of overall efficiency of a thermal power generating system. It depends on a large number of factors, some of which are non-measurable, while data relating to others are seldom available and recorded. However, coal quality (expressed in terms of ‘effective heat value’ (EHV) as kcal/kg) transpires to be one of the important factors that influences HR values and data on EHV are available in any thermal power generating system. In the present work, we propose a prediction interval of the HR values on the basis of only EHV, keeping in mind that coal quality is one of the important (but not the only) factors that have a pronounced effect on the combustion process and hence on HR. The underlying theory borrows the idea of providing simultaneous confidence interval (SCI) to the coefficients of a p-th p(≥1) order autoregressive model (AR(p)). The theory has been substantiated with the help of real life data from a power utility (after suitable base and scale transformation of the data to maintain the confidentiality of the classified document). Scope for formulating strategies to enhance the economy of a thermal power generating system has also been explored.     

Local dependence estimation using semiparametric archimedean copulas

The authors define a new semiparametric Archimedean copula family which has a flexible dependence structure. The generator of the family is a local interpolation of existing generators. It has locally‐defined dependence parameters. The authors present a penalized constrained least‐squares method to estimate and smooth these parameters. They illustrate the flexibility of their dependence model in a bi‐variate survival example.     

独立董事“独立性”探讨

独立董事制度的引进,原本是寄期望于此新体制能够完善我国上市公司的公司治理结构。但由于种种原因,这项新制度并没有起到预期的效果,独立董事的"独立性"作用没有得到应有的发挥。我国的独立董事制度建设应具有权威性,赋予给独立董事的权利与其承担的义务应相当。独立董事职责重大,在实践中如何保证他们职责的有效行使是我们应重点考虑的问题,也是独立董事制度能否真正有效的关键。     

A bayesian estimator for the dependence function of a bivariate extreme‐value distribution

Any continuous bivariate distribution can be expressed in terms of its margins and a unique copula. In the case of extreme‐value distributions, the copula is characterized by a dependence function while each margin depends on three parameters. The authors propose a Bayesian approach for the simultaneous estimation of the dependence function and the parameters defining the margins. They describe a nonparametric model for the dependence function and a reversible jump Markov chain Monte Carlo algorithm for the computation of the Bayesian estimator. They show through simulations that their estimator has a smaller mean integrated squared error than classical nonparametric estimators, especially in small samples. They illustrate their approach on a hydrological data set.