Influence analysis for Poisson inverse Gaussian regression models based on the EM algorithm

For Poisson inverse Gaussian regression models, it is very complicated to obtain the influence measures based on the traditional method, because the associated likelihood function involves intractable expressions, such as the modified Bessel function. In this paper, the EM algorithm is employed as a basis to derive diagnostic measures for the models by treating them as a mixed Poisson regression with the weights from the inverse Gaussian distributions. Several diagnostic measures are obtained in both case-deletion model and local influence analysis, based on the conditional expectation of the complete-data log-likelihood function in the EM algorithm. Two numerical examples are given to illustrate the results.     

Measuring Inequalities without Linearity in Envy: Choquet Integrals for Symmetric Capacities

The (generalized) Gini indices rely on the social welfare function of a decision maker who behaves in accordance with Yaari's model, with a function f that transforms frequencies. This SWF can also be represented as the weighted sum of the welfare of all the possible coalitions in the society, where the welfare of a coalition is defined as the income of the worst-off member of that coalition. We provide a set of axioms (Ak) and prove that the three following statements are equivalent: (i) the decision maker respects (Ak), (ii) f is a polynomial of degree k, (iii) the weight of all coalitions with more than k members is equal to zero. Journal of Economic Literature Classification Number: D63.     

模糊积分模型在公共组织绩效评价中的应用研究

加强对公共组织绩效评价方法的研究,可以有效反映公共组织管理的效率,为上层组织提供决策依据.本文首先指出了模糊积分模型能消除指标间相关影响的客观性的优点,阐明模型在解决公共组织绩效评价问题上的可行性和优势,随后构建了公共组织绩效综合评价的理论模型,创新地引入了对模糊数的调整来确定各指标的权重,提高了权重的准确性.最后通过实证研究,验证该方法的适用性和局限性,为公共组织绩效评估的实际操作提出了若干建议.     

航材备件需求预测模型与应用研究

分析了航材消耗与需求特点,从计算航材换件次数的角度进行分析,采用简单的函数拟合算法,给出需求规律拟合公式,结合具体实例进行了器材需求预测,并给出预测。计算结果表明,计算过程简单,拟合效果较好,易于工程采用。     

Mixture representations for discrete Linnik laws

In this paper we give mixture representations for the discrete Mittag–Leffler and Linnik laws. Our results form the discrete analogues of the mixture representations for the generalized symmetric Linnik distribution obtained by P AKES (1998). As an application, we derive the infinite divisibility of mixtures of Mittag–Leffler distributions. Alternative mixture representations in terms of discrete stable distributions are also presented.     

Limit theorems for multivariate discrete distributions

According to the usual law of small numbers a multivariate Poisson distribution is derived by defining an appropriate model for multivariate Binomial distributions and examining their behaviour for large numbers of trials and small probabilities of marginal and simultaneous successes. The weak limit law is a generalization of Poisson's distribution to larger finite dimensions with arbitrary dependence structure. Compounding this multivariate Poisson distribution by a Gamma distribution results in a multivariate Pascal distribution which is again asymptotically multivariate Poisson. These Pascal distributions contain a class of multivariate geometric distributions. Finally the bivariate Binomial distribution is shown to be the limit law of appropriate bivariate hypergeometric distributions. Proving the limit theorems mentioned here as well as understanding the corresponding limit distributions becomes feasible by using probability generating functions.     

三主桁连续钢桁拱桥整体节点有限元分析

东平水道桥是武广高速铁路上一座四线铁路桁架拱桥,主跨结构为99m+242m+99m的三主桁连续钢桁拱,主桁采用整体节点形式,三主桁内力分析表明中桁处受力最大。节点板联结着主桁、腹杆、横梁、平联等各类杆件,结构及受力均较复杂,节点应力分布是设计中的关键问题之一。文章利用有限元程序对其特殊位置节点板进行应力分析,研究了其应力分布及传力特性,为设计提供依据和给同类桥梁提供参考。研究表明通过调整节点构造和板件刚度,节点具有足够的受力与传力功能。