Allocation strategies of standby redundancies in series/parallel system

This article deals with the topic of optimal allocation of two standby redundancies in a two-component series/parallel system. There are two original components C₁ and C₂ which can be used to construct a series/parallel system, and two spares R₁ (same as C₁) and R₂ (different from both C₁ and C₂) at hand with them being standby redundancies so as to enhance the reliability level of the system. The goal for an engineer is to seek after the optimal allocation policy in this framework. It is shown that, for the series structure, the engineer should allocate R₂ to C₁ and R₁ to C₂ provided that C₁ (or R₁) performs either the best or worst among all the units; otherwise, the allocation policy should be reversed. For the parallel structure, the optimal allocation strategy is just opposed to that of series case. We also provide some numerical examples for illustrating the theoretical results.     

冗员约束影响了国有企业的投资行为吗？

以2003-2014年间国有上市公司为研究对象,对冗员的重要经济后果进行了实证检验.研究发现,冗员不仅会加大国有企业的自由现金约束及国企高管的道德风险,还具有显著的投资约束作用.进一步研究得出,适度冗员和过度冗员具有不同的经济后果和治理后果,适度冗员会增强对国企高管的负激励,提升高管的投资动力,而随着冗员的持续增加,自由现金流约束作用和道德风险强化效应则会降低企业的投资规模.同时,冗员与投资效率的关系也进一步佐证了适度冗员的治理作用,适度冗员会降低国企的过度投资水平,而存在过度冗员现象的企业其过度投资也更严重.另外,冗员与投资规模之间的关系仅在公益类国企显著,在商业类国企中并不存在显著的负相关关系;冗员对企业投资的约束作用也仅存在于地方国企,而在中央国企则缺乏此约束作用的证据.外部环境变量,如产品市场竞争程度、企业所在地的GDP增长率和企业所在地的财政赤字率,对冗员与企业投资行为之间的关系没有影响.     

A Resource-Intensive Medicare Patient Effect of Profit Margin on Care

No abstract available for this article.     

The optimal allocation of active redundancies to k-out-of-n systems with respect to hazard rate ordering

This paper deals with the allocation of active redundancies to a k-out-of-n system with independent and identically distributed (i.i.d.) components in the sense of the hazard rate order. It is shown that the system's hazard rate may be decreased by balancing the allocation of active redundancies. This generalizes the main result of Singh and Singh (1997) and improves the corresponding one of Hu and Wang (2009) as well. As an application, we build the reversed hazard rate order on order statistics from sample having proportional hazard rates, which strengthens the usual stochastic order in Theorem 2.1 of Pledger and Proschan (1971) to the reversed hazard order in the situation that all components are of (rational) proportional hazard rates.     

郑玄校《仪礼》不从误字、衍字、倒文、坏字考

《仪礼》在汉代有今古文两种本子。两种本子在长期传抄过程中都难免产生误字、衍字、倒文、坏字。郑玄在给《仪礼》作注时,凡遇误、衍、倒、坏之字则皆不从,而必择无误之字从之,而不论其为今文、古文,从而为后人留下了一部校勘精审、错误较少的《仪礼》,并流传至今。本文尽索《仪礼》中郑玄所不从之误、衍、倒、坏之字例而一一考辨之,以明郑玄之所以不从之由。