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.     

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。     

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.     

真景物与真感情——辛弃疾田园词的意境美

辛弃疾田园词景真、情真,又能将两者紧密地结合起来,相融相生成自然和谐之境,富有意境美。他或者将景物人格化,作为主观情感的寄托,或者“以我观物,使物皆着我之色彩”。无论是借景托情,还是情景俱到、相间相融,都各有其妙。     

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.     

长歌当哭，寓悲于闲——晚唐送人赴任诗情感探微

送人赴任之作,在唐代别离诗中占有相当大比例.盛唐人的这类诗歌,往往忽略了别离之伤情.反之,晚唐却固囿于这一伤情,并将此进一步深化,深化的结果,就是诗歌中闲情的泛滥.这不是偶然的,而是晚唐文人大范围接受佛道思想的必然结果.     

西部诗人高凯的乡土世界

甘肃诗人高凯的乡土诗在中国西部当代诗歌中是独特的,他构筑的乡土世界已逐渐引起评论家的关注并赢得较高的评价。他的乡土诗主要有这样三部分组成:一,风俗画的展现;二,乡情、乡愁的吟唱;三,家园意识的追寻。高凯的乡土世界是厚重的、完整的。诗歌具有哲学和人类学的思想高度。     

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。     

从换韵看王令《梦蝗》诗的情绪变化

换韵与情绪宣泄关系十分密切,从王令《梦蝗》诗可以明显看到这一点。从《梦蝗》诗的换韵中人们可以有效地把握王令诗的情绪节奏变化特征,真正理解作为"蓄含悲愤"而又"笔力恣肆"诗人的情绪结构本质。