Proportional reversed hazard rate model and its applications

The purpose of this paper is to study the structure and properties of the proportional reversed hazard rate model (PRHRM) in contrast to the celebrated proportional hazard model (PHM). The monotonicity of the hazard rate and the reversed hazard rate of the model is investigated. Some criteria of aging are presented and the inheritance of the aging notions (of the base distribution) by the PRHRM is studied. Characterizations of the model involving Fisher information are presented and the statistical inference of the parameters is discussed. Finally, it is shown that several members of the proportional reversed hazard rate class have been found to be useful and flexible in real data analysis.     

北魏孝文帝定姓族制度散论

北魏孝文帝实施定姓族 ,首先 ,它既是北魏汉化政策的继续和发展 ,也是北魏历史发展的客观需要 ,在当时具有一定的现实意义 ;其次 ,姓族制度的实施在消除民族间的隔阂、加强北魏政权的统治以及提高鲜卑人的文化水平等方面也起了一定的积极作用 ;其三 ,姓族制度的实施与北魏政权的政治有密切的关系 ,不同时期所发挥的作用不同 ,应作具体分析 ,不能说姓族制对北魏政权的灭亡起了最直接、最主要的作用。     

论在解放思想中统一思想

解放思想和统一思想是辩证统一的关系 ,在解放思想中统一思想是马克思主义认识论的一条基本规律 ,这既是我们党的宝贵经验 ,也是当前历史任务对我们提出的新要求     

中国古代时空秩序的修辞建构及其理据

根据日照长短和方向建构时空秩序,是中国古人对与自身生存息息相关的太阳长期细微观察的结果,这里存在着客观参照物的选择、主体思维方式以及学理层面的解释依据。     

中国工业企业投资的融资约束研究

文章利用工业企业1997—2004年的面板数据,对中国工业企业投资中的融资约束问题进行了研究,发现中国企业中年轻企业或非国有企业都存在融资约束。进一步作者利用开工时间和控股权,对融资约束情况作了交叉的先验分类,把企业分成国有老企业、国有新企业、非国有老企业、非国有新企业四类,对这四类企业的回归分析发现,开工时间长或国有控股的企业,不受融资约束,而非国有新企业却明显受到融资约束。这一经验结论准确反映了我国贷款中推行的担保制度对投资活动的影响。     

论网络社会秩序的维护

本文从网络社会秩序的范畴角度入手 ,分析了网络社会秩序维护的必要性 ,并就如何维护问题提出了相关的对策     

Sampling design proportional to order statistic of auxiliary variable

The sampling designs dependent on sample moments of auxiliary variables are well known. Lahiri (Bull Int Stat Inst 33:133–140, 1951) considered a sampling design proportionate to a sample mean of an auxiliary variable. Sing and Srivastava (Biometrika 67(1):205–209, 1980) proposed the sampling design proportionate to a sample variance while Wywiał (J Indian Stat Assoc 37:73–87, 1999) a sampling design proportionate to a sample generalized variance of auxiliary variables. Some other sampling designs dependent on moments of an auxiliary variable were considered e.g. in Wywiał (Some contributions to multivariate methods in, survey sampling. Katowice University of Economics, Katowice, 2003a); Stat Transit 4(5):779–798, 2000) where accuracy of some sampling strategies were compared, too.These sampling designs cannot be useful in the case when there are some censored observations of the auxiliary variable. Moreover, they can be much too sensitive to outliers observations. In these cases the sampling design proportionate to the order statistic of an auxiliary variable can be more useful. That is why such an unequal probability sampling design is proposed here. Its particular cases as well as its conditional version are considered, too. The sampling scheme implementing this sampling design is proposed. The inclusion probabilities of the first and second orders were evaluated. The well known Horvitz–Thompson estimator is taken into account. A ratio estimator dependent on an order statistic is constructed. It is similar to the well known ratio estimator based on the population and sample means. Moreover, it is an unbiased estimator of the population mean when the sample is drawn according to the proposed sampling design dependent on the appropriate order statistic.     

Maximum Likelihood Inference for Log-linear Models Subject to Constraints of Double Monotone Dependence

To model an hypothesis of double monotone dependence between two ordinal categorical variables A and B usually a set of symmetric odds ratios defined on the joint probability function is subject to linear inequality constraints. Conversely in this paper two sets of asymmetric odds ratios defined, respectively, on the conditional distributions of A given B and on the conditional distributions of B given A are subject to linear inequality constraints. If the joint probabilities are parameterized by a saturated log-linear model, these constraints are nonlinear inequality constraints on the log-linear parameters. The problem here considered is a non-standard one both for the presence of nonlinear inequality constraints and for the fact that the number of these constraints is greater than the number of the parameters of the saturated log-linear model.This work has been supported by the COFIN 2002 project, references 2002133957_002, 2002133957_004. Preliminary findings have been presented at SIS (Società Italiana di Statistica) Annual Meeting, Bari, 2004.     

农户借款的供求约束及解除

我国的农村金融改革一直是政府导向的,包括现在进行的农村信用社改革。农村金融改革应充分考虑到农村经济主体对资金的需求特征,只有这样,才不致于出现供给缺位和需求得不到满足的情况。因此,研究我国农村中最大的经济主体———农户与正规金融机构之间的借款行为,通过对借贷双     

A relation for the covariances of order statistics from n independent and non-identically distributed random variables

We derive a simple relation satisfied by the covariances of order statistics in the i.i.d. case and then generalize it to the case when the variables are independent and non-identically distributed. This relation could be employed successfully either to check the calculations or to reduce the amount of direct computations involved in evaluating the covariances of order statistics from an outlier model.