A Note on Minimax Mixture of Distributions Free Procedure for Inventory Model with Variable Lead Time

In recent papers, Moon and Choi (1998) and Hariga and Ben-Daya (1999)considered a continuous review inventory model with a mixture of backordersand lost sales in which the lead time, the order quantity, and the reorder pointare decision variables was studied. Moreover, they also develop a minimaxdistribution free procedure for the problem. While the demands of differentcustomers are not identical in the lead time, then we can't only use a singledistribution (such as Moon & Choi (1998) and Hariga & Ben-Daya (1999))to describe the demand of the lead time. Hence, we correct and extend the modelof Moon and Choi (1998) and Hariga and Ben-Daya (1999) by considering thelead time demand with the mixture of distributions. In addition, we also applythe minimax mixture of distributions free approach to the model by simultaneouslyoptimizing the order quantity, the reorder point, and the lead time to devise a practical procedure which can be used without specific information on demand distribution.     

Three Corrected Score Tests for Generalized Linear Models with Dispersion Covariates

We develop three corrected score tests for generalized linear models with dispersion covariates, thus generalizing the results of Cordeiro , Ferrari and Paula (1993) and Cribari-Neto and Ferrari (1995) . We present, in matrix notation, general formulae for the coefficients which define the corrected statistics. The formulae only require simple operations on matrices and can be used to obtain analytically closed-form corrections for score test statistics in a variety of special generalized linear models with dispersion covariates. They also have advantages for numerical purposes since our formulae are readily computable using a language supporting numerical linear algebra. Two examples, namely, iid sampling without covariates on the mean or dispersion parameter oand one-way classification models, are given. We also present some simulations where the three corrected tests perform better than the usual score test, the likelihood ratio test and its Bartlett corrected version. Finally, we present a numerical example for a data set discussed by Simonoff and Tsai (1994) .     

两阶段订购模式下的供应链契约协调

本文针对短生命周期产品需求的不确定性,建立允许调整订货量的两阶段订货模型,由此得到销售商应该采取的最优订货量.在此基础上,运用契约协调机制,从而达到供应链的协调.     

亚洲金融危机之后的深层思考

进入20世纪90年代以来,全球各类金融危机频频发生。影响国际经济金融秩序的因素发生了新变化,目前的国际金融秩序已经不能适应国际政治格局和经济、技术发展趋势,不能适应调整当前国际金融关系的需要,必须进行变革,并建立公正、合理的国际金融新秩序。     

经济全球化中企业生产方式的转换

本文通过分析美国、日本两个"世界工厂"的生产方式,阐述了大规模生产与大规模定制的异同与优劣势,提出了生产方式由大规模生产向大规模定制转变的思路。同时,结合我国的实际情况分析了我国成为"世界工厂"的优势和劣势,为中国企业在走向"世界工厂"的进程中选择适合自身的生产方式,实现企业的再发展提供一些思路。     

审慎看待“幸福指数”

近两年来，在我国的媒体和各级官员的话语中，频频出现“幸福指数”或类似的表达。其实，作为舶来品的“幸福指数”，相当程度上正被众多的媒体和官员误读。“幸福指数”不可能替代GDP。为了避免“幸福指数”的运用走向异化、陷入贻笑大方的窘境，我们必须审慎看待“幸福指数”。     

Measuring abnormal daily trading volume for samples of NYSE/ASE and NASDAQ securities using parametric and nonparametric test statistics

We extend prior research on the empirical properties of daily trading volume and methods to detect abnormal trading volume in two ways. We compare the performance of a nonparametric test statistic with the parametric test statistic used in prior research and we study samples of NASDAQ securities as well as samples of NYSE/ASE securities. Prior research has focused exclusively on NYSE securities. We find the nonparametric test statistic is more powerful in detecting abnormal trading volume than the parametric test statistic in both samples of NYSE/ASE and NASDAQ securities. We also document that abnormal trading volume will be detected more often in samples of NYSE/ASE securities compared to NASDAQ securities.     

Is there a pecking order? Evidence from a panel of IPO firms

We test the pecking order model of capital structure by examining the financing of firms that went public in 1983. We estimate a logit to predict external financing, and a multinomial logit to predict the type of financing using data on the IPO firms' security offerings during 1984–1992. Our results indicate that the probability of obtaining external funds is unrelated to the shortfall in internally generated funds, although firms with cash surpluses avoid external financing. Firms that access the capital markets do not follow the pecking order when choosing the type of security to offer.     

论统计过程控制的实施

为提高中国石油天然气集团公司产品、工程和服务质量总体水平。提高企业经济效益，全面推进具有国际竞争力的跨国企业集团建设，中国石油天然气集团公司决定在各企业推广应用统计过程控制技术。通过控制图的具体实施．由推行小组对控制图的实施成果进行评估，并根据评估结果进行有针对性的改善。