Lower confidence bounds for percentiles of weibull and birnbaum-saunders distributions

Approximate lower confidence bounds on percentiles of the Weibull and the Birnbaum-Saunders distributions are investigated. Asymptotic lower confidence bounds based on Bonferroni's inequality and the Fisher information are discussed, and parametric bootstrap methods to provide better bounds are considered. Since the standard percentile bootstrap method typically does not perform well for confidence bounds on quantiles, several other bootstrap procedures are studied via extensive computer simulations. Results of the simulations indicate that the bootstrap methods generally give sharper lower bounds than the Bonferroni bounds but with coverages still near the nominal confidence level. Two illustrative examples are also presented, one for tensile strength of carbon micro-composite specimens and the other for cycles-to-failure data.     

Bias-calibrated estimation from sample surveys containing outliers

We discuss the problem of estimating finite population parameters on the basis of a sample containing representative outliers. We clarify the motivation for Chambers's bias-calibrated estimator of the population total and show that bias calibration is a key idea in constructing estimators of finite population parameters. We then link the problem of estimating the population total to distribution function or quantile estimation and explore a methodology based on the use of Chambers's estimator. We also propose methodology based on the use of robust estimates and a bias-calibrated form of the Chambers and Dunstan estimator of the population distribution function. This proposal leads to a bias-calibrated estimator of the population total which is an alternative to that of Chambers. We present a small simulation study to illustrate the utility of these estimators.     

川东北地区新石器时代考古学文化初探

长期以来,学术界对川东北地区新石器时代考古学文化面貌和时代的认识比较模糊.本文通过与成都平原的宝墩文化和三峡地区龙山时代文化相比较,认为通江擂鼓寨遗址和巴中月亮岩遗址受三峡地区龙山时代文化影响较大,绵阳边堆山遗址受宝墩文化影响较大,广元张家坡遗址、邓家坪遗址则受到宝墩文化和三峡地区龙山时代文化的共同影响.宝墩文化和三峡地区龙山时代文化在川东北地区的分布大致以嘉陵江为界.     

Modified goodness-of-fit test for the laplace distribution

In this paper critical values of the Anderson-Darling and Cra[macute]er-von Mises are given for the Laplace distribution for maximum likelihood estimation of the location and scale parameters. The power of these tests is investigated for a number of alternative distributions. The Anderson-Darling test yields higher power generally than the Cra[macute]er-von Mises test.     

The Distribution of the Kolmogorov–Smirnov,Cramer–von Mises,and Anderson–Darling Test Statistics for Exponential Populations with Estimated Parameters

This article presents a derivation of the distribution of the Kolmogorov–Smirnov, Cramer–von Mises, and Anderson–Darling test statistics in the case of exponential sampling when the parameters are unknown and estimated from sample data for small sample sizes via maximum likelihood.     

高原山区人口分布特征及其主要影响因素——基于毕节地区的Panel Data计量模型分析

本文基于1987～2007年毕节地区八个县市经济、社会和资源环境方面的面板数据,考察了资源环境、经济水平和社会发展等因素对毕节人口分布变动的影响。研究发现,毕节各县市的人口总量和人口密度稳步增加,呈现协同式的增长态势,但各县市之间增长速度快慢不一,显示了区域间的差异;自然环境因素对人口地域分布变动的影响日趋减弱,但是减小的幅度并不大,说明了自然环境因素对人口分布变动的影响是根深蒂固的;经济水平和社会发展因素对人口密度变动的影响越来越大,其中尤以人均GDP和医疗条件变量更为显著;就人口密度的动态变化影响而言,除了受资源环境、社会经济发展因素的共同影响之外,毕节各个县市还表现出其个体显著差异的特征。     

北京市优质公共资源配置与人口疏解研究

文章分析了北京市优质公共资源配置与人口分布现状,并提出实现中心城人口疏解的相应对策。指出,人口迁移的一个重要因素是各种优质公共资源的吸引。北京的教育、医疗卫生、文化、体育、公共交通等优质公共资源在中心城高度聚集是导致人口在中心城聚集的一个重要原因。为此,要疏解中心城人口,需采取如下措施:政府主导,在新城高标准配置优质公共资源;优先疏解中心城教育、医疗资源;强化轨道交通的引导作用,降低新城居民出行的成本。     

An Integrated Decision Methodology for Designing and Operating an Air‐Express Courier's Distribution Network*

DHL, an international air‐express courier, has been operating in Hong Kong for many years. In 1998, the new international airport located at a site considerably distant from the old location opened in Hong Kong (HK). Other airport‐related infrastructure facilities have also been developed or are being developed, resulting in major changes in transport structure as well as a shift in customer demand. In this paper a multiyear distribution network is designed for DHL(HK) using an integrated network design methodology, which consists of a macro model and a micro model. The macro model, a mixed 0–1 LP, determines in an aggregate manner the least‐cost distribution network. The micro model, a simulation, evaluates the operational viability and efficacy of the network according to its service coverage and service reliability. We also illustrate how coverage and reliability can be improved via the integrated use of the two models. Extensive discussion on relevant planning and operational issues of an air‐express courier are included. The methodology has been successfully implemented at DHL(HK). It has been used to design the network, to test strategic decisions, and to update the network.     

On a class of distributions on the simplex

In the present paper we define and investigate a novel class of distributions on the simplex, termed normalized infinitely divisible distributions, which includes the Dirichlet distribution. Distributional properties and general moment formulae are derived. Particular attention is devoted to special cases of normalized infinitely divisible distributions which lead to explicit expressions. As a by-product new distributions over the unit interval and a generalization of the Bessel function distribution are obtained.     

中国基尼系数警戒线的一个估计

 本文基于1978-2007年我国居民收入分配的分组数据测算了多个基尼系数,采用参数和非参数多种方法估计了基尼系数的分布服从渐近正态分布,最后基于大样本渐近特征给出了我国基尼系数警戒水平的估计值。