A bayesian estimator for the dependence function of a bivariate extreme‐value distribution

Any continuous bivariate distribution can be expressed in terms of its margins and a unique copula. In the case of extreme‐value distributions, the copula is characterized by a dependence function while each margin depends on three parameters. The authors propose a Bayesian approach for the simultaneous estimation of the dependence function and the parameters defining the margins. They describe a nonparametric model for the dependence function and a reversible jump Markov chain Monte Carlo algorithm for the computation of the Bayesian estimator. They show through simulations that their estimator has a smaller mean integrated squared error than classical nonparametric estimators, especially in small samples. They illustrate their approach on a hydrological data set.     

A Non-parametric Frailty Model for Temporally Clustered Multivariate Failure Times

Abstract A model is introduced here for multivariate failure time data arising from heterogenous populations. In particular, we consider a situation in which the failure times of individual subjects are often temporally clustered, so that many failures occur during a relatively short age interval. The clustering is modelled by assuming that the subjects can be divided into ‘internally homogenous’ latent classes, each such class being then described by a time‐dependent frailty profile function. As an example, we reanalysed the dental caries data presented earlier in Härkänen et al. [Scand. J. Statist. 27 (2000) 577], as it turned out that our earlier model could not adequately describe the observed clustering.     

基于TOPSIS理论的企业供应商选择应用

供应链管理已经成为企业获取竞争优势的手段,供应商选择是企业构建供应链体系的重要内容。TOPSIS是一种简单易行的多因素选优的理论方法,它利用熵来确定评价指标的权重,避免了在确定评价指标权重时主观因素的影响,为公司的供应商选择提供了一种科学、量化、高效的手段。文章回顾了供应商选择的理论现状,介绍了TOPSIS理论模型和利用它进行供应商选择的步骤,通过对典型企业的深入调研,阐述了该企业如何应用TOPSIS进行供应商选择。     

附加价值链与企业长程发展

企业附加价值链表征企业文化的浓缩 ,是企业发展的生命线。企业附加价值链清晰、完备与否 ,是剖析企业存在、发展的根本之所在 ,也是考查、评价企业现状的基本依据。     

略论邓小平理论萌芽的界定及其标志

作为邓小平理论萌芽的标志不是某一具体的时间、论著、观点。对邓小平理论萌芽应作出系统的、全面的科学界定。邓小平理论萌芽的标志应该是时间段、论著链、观点网     

A Unified Approach to the Characterization of Equivalence Classes of DAGs, Chain Graphs with no Flags and Chain Graphs

Abstract.  A Markov property associates a set of conditional independencies to a graph. Two alternative Markov properties are available for chain graphs (CGs), the Lauritzen–Wermuth–Frydenberg (LWF) and the Andersson–Madigan– Perlman (AMP) Markov properties, which are different in general but coincide for the subclass of CGs with no flags . Markov equivalence induces a partition of the class of CGs into equivalence classes and every equivalence class contains a, possibly empty, subclass of CGs with no flags itself containing a, possibly empty, subclass of directed acyclic graphs (DAGs). LWF-Markov equivalence classes of CGs can be naturally characterized by means of the so-called largest CGs , whereas a graphical characterization of equivalence classes of DAGs is provided by the essential graphs . In this paper, we show the existence of largest CGs with no flags that provide a natural characterization of equivalence classes of CGs of this kind, with respect to both the LWF- and the AMP-Markov properties. We propose a procedure for the construction of the largest CGs, the largest CGs with no flags and the essential graphs, thereby providing a unified approach to the problem. As by-products we obtain a characterization of graphs that are largest CGs with no flags and an alternative characterization of graphs which are largest CGs. Furthermore, a known characterization of the essential graphs is shown to be a special case of our more general framework. The three graphical characterizations have a common structure: they use two versions of a locally verifiable graphical rule. Moreover, in case of DAGs, an immediate comparison of three characterizing graphs is possible.     

构建研产销供应链促进高科技企业的发展

加入WTO对我国高科技企业来说是更大的挑战。本文讨论的是用供应链管理的思想来推进高新技术产业的发展。以高科技企业为核心构建或以高新技术改造供应链 ,促进科研成果的转化 ,增强核心企业的竞争力。从强化核心竞争力、战略联盟、信息技术等方面提出了构建研产销供应链的方法。     

丰水区筑坝截流——调丰补歉

该文从中国人口快速增长、经济建设加快、用水量逐年增大 ,加上气候变暖、少雨干旱将持续到 2 0 15年 ,我国北方水生态环境日趋恶化现状 ,说明在丰水区筑坝截流、调丰补歉势在必行 ,完全符合生态经济学发展原则和国际水法     

国家财政对农业投入的分析与预测——基于状态空间模型的实证分析

国家财政对农业的投入是影响农业发展的重要因素。收集了建国以来国家财政对农业投入的数据,分析构造出状态空间模型,应用卡尔曼滤波估计出状态向量,挖掘出隐藏在数据内部的变化特征,分析国家财政对农业投入的实际情况,并对未来几年的农业投入进行预测。     

经济增长、模型再造与农村经济增长方式的转变

经济增长理论是社会经济发展的一种理论反映,源于斯密和李嘉图为代表的古典经济学派,是二战后在发达国家广泛流行的经济理论。但是,发达国家经济学家自身存在的认识论缺陷使其不可能建立科学完整的经济增长理论及模型,因此还必须遵循马克思的方法论从理论为实际的反映入手建立科学模型,并以此指导中国社会经济增长实践,特别是农村经济增长方式的转变实践。