Gini’s nuclear family

The purpose of this paper is to justify the use of the Gini coefficient and two close relatives for summarizing the basic information of inequality in distributions of income. To this end we employ a specific transformation of the Lorenz curve, the scaled conditional mean curve, rather than the Lorenz curve as the basic formal representation of inequality in distributions of income. The scaled conditional mean curve is shown to possess several attractive properties as an alternative interpretation of the information content of the Lorenz curve and furthermore proves to yield essential information on polarization in the population. The paper also provides asymptotic distribution results for the empirical scaled conditional mean curve and the related family of empirical measures of inequality.      

基于直接接触凝结理论的汽液两相流升压模型

针对汽液两相流升压装置利用经验模型计算的过程中，仅能对出口压力进行计算，且计算值与实验值有较大误差的弱点，提出了用直接接触凝结（DCC）的理论求解汽液两相流的一维理论模型。计算升压装置的最大出口压力，分析其他参量的变化规律。结果表明，汽液两相流在凝结激波前为泡沫流，在凝结激波后完全凝结成单相水的情况下，升压装置的出口压力达到最大值。     

Finite Sample Performance in Cointegration Analysis of Nonlinear Time Series with Long Memory

Nonlinear functions of multivariate financial time series can exhibit long memory and fractional cointegration. However, tools for analysing these phenomena have principally been justified under assumptions that are invalid in this setting. Determination of asymptotic theory under more plausible assumptions can be complicated and lengthy. We discuss these issues and present a Monte Carlo study, showing that asymptotic theory should not necessarily be expected to provide a good approximation to finite-sample behavior.     

冠状动脉收缩期受压持续到舒张期的模拟实验分析

利用研制的心肌桥模拟装置,对冠状动脉受压迫状态建立了圆形收缩的实验模型,进行了冠状动脉受心肌桥压迫持续到舒张期情况下的血压和流量模拟实验.实验研究表明,冠状动脉面积收缩接近到原来的20%时,远段收缩压迅速与近段收缩压分离;当冠状动脉面积收缩到小于原来的20%时,近段收缩压迅速上升,远段压力从不稳定状态迅速过渡到收缩压呈反向分布状态.心率和近段血压范围不变时,流量随着收缩程度的增加而增加.     

Nonresponse weighting adjustment using estimated response probability

To reduce nonresponse bias in sample surveys, a method of nonresponse weighting adjustment is often used which consists of multiplying the sampling weight of the respondent by the inverse of the estimated response probability. The authors examine the asymptotic properties of this estimator. They prove that it is generally more efficient than an estimator which uses the true response probability, provided that the parameters which govern this probability are estimated by maximum likelihood. The authors discuss variance estimation methods that account for the effect of using the estimated response probability; they compare their performances in a small simulation study. They also discuss extensions to the regression estimator.     

经济全球化作用下国际资本流动的动力机制研究

经济全球化的深入发展以及与之相关的信息技术、知识经济和跨国公司的飞速发展给国际资本流动带来了深刻的影响。国际资本流动的新旧因素在全球化条件下重新组合,并在跨国公司的全球经营战略的推力和以信息技术、知识经济、企业生态环境为代表的创新因素的引力作用下,形成以跨国公司为主体的,沿着价值链的各个节点组建全球生产的驱动型动力机制,最后以中国为例探讨影响中国引资的因素及对策和建议。     

New methods for fitting multiple sinusoids from irregularly sampled data

A novel framework is proposed for the estimation of multiple sinusoids from irregularly sampled time series. This spectral analysis problem is addressed as an under-determined inverse problem, where the spectrum is discretized on an arbitrarily thin frequency grid. As we focus on line spectra estimation, the solution must be sparse, i.e. the amplitude of the spectrum must be zero almost everywhere. Such prior information is taken into account within the Bayesian framework. Two models are used to account for the prior sparseness of the solution, namely a Laplace prior and a Bernoulli–Gaussian prior, associated to optimization and stochastic sampling algorithms, respectively. Such approaches are efficient alternatives to usual sequential prewhitening methods, especially in case of strong sampling aliases perturbating the Fourier spectrum. Both methods should be intensively tested on real data sets by physicists.     

Data skeletons: simultaneous estimation of multiple quantiles for massive streaming datasets with applications to density estimation

We consider the problem of density estimation when the data is in the form of a continuous stream with no fixed length. In this setting, implementations of the usual methods of density estimation such as kernel density estimation are problematic. We propose a method of density estimation for massive datasets that is based upon taking the derivative of a smooth curve that has been fit through a set of quantile estimates. To achieve this, a low-storage, single-pass, sequential method is proposed for simultaneous estimation of multiple quantiles for massive datasets that form the basis of this method of density estimation. For comparison, we also consider a sequential kernel density estimator. The proposed methods are shown through simulation study to perform well and to have several distinct advantages over existing methods.     

当代中国的社会变迁与女性犯罪

当前我国处于急剧的社会变迁时期,社会变迁带来的社会角色的变迁、社会地位的分化、社会整合力的减弱以及社会流动的加速,是当代女性犯罪不断上升和蔓延的重要原因.本文从社会变迁角度探讨当代女性犯罪的复杂成因.     

A simple estimator for a shared frailty regression model

Summary. We propose a simple estimation procedure for a proportional hazards frailty regression model for clustered survival data in which the dependence is generated by a positive stable distribution. Inferences for the frailty parameter can be obtained by using output from Cox regression analyses. The computational burden is substantially less than that of the other approaches to estimation. The large sample behaviour of the estimator is studied and simulations show that the approximations are appropriate for use with realistic sample sizes. The methods are motivated by studies of familial associations in the natural history of diseases. Their practical utility is illustrated with sib pair data from Beaver Dam, Wisconsin.