永乐家电能否“永乐”京城

上海家电连锁大鄂永乐家电在经过两年筹划之后于6月18日正式登陆北京．开设了在北京的第一家店。永乐家电董事长陈晓说：“如果不拿下北京与广东的市场，永乐就谈不上是全国性的连锁。“陈晓的这番话让我们看出永乐进入北京的决心，但永乐究竟是“永乐”京城还是永乐自身，是包括像国美、苏宁这样大的家电连锁企业所共同关心的问题。     

农村税费改革相关问题的深入思考

针对进一步扩大农村税费改革试点的要求，章从农村税费改革成功与否的衡量标准入手，对农村税费改革中难点问题的根本症结进行了深入分析．指出问题的根本源自不同利益主体间利益的重新分配，并在此基础上提出了解决问题的基本思路。     

Improved estimation of portfolio value‐at‐risk under copula models with mixed marginals

Portfolio value‐at‐risk (PVAR) is widely used in practice, but recent criticisms have focused on risks arising from biased PVAR estimates due to model specification errors and other problems. The PVAR estimation method proposed in this article combines generalized Pareto distribution tails with the empirical density function to model the marginal distributions for each asset in the portfolio, and a copula model is used to form a joint distribution from the fitted marginals. The copula–mixed distribution (CMX) approach converges in probability to the true marginal return distribution but is based on weaker assumptions that may be appropriate for the returns data found in practice. CMX is used to estimate the joint distribution of log returns for the Taiwan Stock Exchange (TSE) index and the associated futures contracts on SGX and TAIFEX. The PVAR estimates for various hedge portfolios are computed from the fitted CMX model, and backtesting diagnostics indicate that CMX outperforms the alternative PVAR estimators. © 2006 Wiley Periodicals, Inc. Jrl Fut Mark 26:997–1018, 2006     

对《形状和位置公差》新标准的理解和应用

通过对《形状和位置公差》新、旧国际的对比，综述了新、旧标准间的不同之处、便于迅速了解和应用新标准。