Estimating household structure in ancient China by using historical data: a latent class analysis of partially missing patterns

Summary.  Social data often contain missing information. The problem is inevitably severe when analysing historical data. Conventionally, researchers analyse complete records only. Listwise deletion not only reduces the effective sample size but also may result in biased estimation, depending on the missingness mechanism. We analyse household types by using population registers from ancient China (618–907 AD) by comparing a simple classification, a latent class model of the complete data and a latent class model of the complete and partially missing data assuming four types of ignorable and non-ignorable missingness mechanisms. The findings show that either a frequency classification or a latent class analysis using the complete records only yielded biased estimates and incorrect conclusions in the presence of partially missing data of a non-ignorable mechanism. Although simply assuming ignorable or non-ignorable missing data produced consistently similarly higher estimates of the proportion of complex households, a specification of the relationship between the latent variable and the degree of missingness by a row effect uniform association model helped to capture the missingness mechanism better and improved the model fit.     

一种求解双目标线性规划的方法及其在上海市土地使用和交通方面的应用

本文介绍了一种求解双目标线性规划(SBLP)的方法.根据上海市土地使用与交通的现状建立了一个拟动态的模型(BOLT),并用该方法加以求解。根据得到的解对上海市土地使用与交通相互作用的情况进行了分析。     

经济全球化影响下的中国计划生育发展趋势

中国的计划生育是在计划经济体制下形成的,其特点多数与经济全球化的规则有着较大的差距。因此,经济全球化和中国加入世贸组织对中国计划生育的影响是全面而深刻的。在经济全球化的影响下,中国计划生育的发展趋势主要体现在六个方面。     

An individual measure of relative survival

Summary.  Relative survival techniques are used to compare survival experience in a study cohort with that expected if background population rates apply. The techniques are especially useful when cause-specific death information is not accurate or not available as they provide a measure of excess mortality in a group of patients with a certain disease. Whereas these methods are based on group comparisons, we present here a transformation approach which instead gives for each individual an outcome measure relative to the appropriate background population. The new outcome measure is easily interpreted and can be analysed by using standard survival analysis techniques. It provides additional information on relative survival and gives new options in regression analysis. For example, one can estimate the proportion of patients who survived longer than a given percentile of the respective general population or compare survival experience of individuals while accounting for the population differences. The regression models for the new outcome measure are different from existing models, thus providing new possibilities in analysing relative survival data. One distinctive feature of our approach is that we adjust for expected survival before modelling. The paper is motivated by a study into the survival of patients after acute myocardial infarction.     

海峡两岸司法协助模式新探

区际司法协助,是中国恢复对香港和澳门行使主权后最迫切需要解决的问题之一。现今在我国区际司法协助实践中已经出现了"安排模式",这种模式初步解决了我国的区际司法协助问题,但还不能说是我国开展区际司法协助的唯一模式。而海峡两岸区际冲突法的独特性和复杂性,使示范立法模式有其运用的空间。     

A Comparative Study of Model-based Tests of Independence for Ordinal Data Using the Bootstrap

When analyzing categorical data using loglinear models in sparse contingency tables, asymptotic results may fail. In this paper the empirical properties of three commonly used asymptotic tests of independence, based on the uniform association model for ordinal data, are investigated by means of Monte Carlo simulation. Five different bootstrapped tests of independence are presented and compared to the asymptotic tests. The comparisons are made with respect to both size and power properties of the tests. Results indicate that the asymptotic tests have poor size control. The test based on the estimated association parameter is severely conservative and the two chi-squared tests (Pearson, likelihood-ratio) are both liberal. The bootstrap tests that either use a parametric assumption or are based on non-pivotal test statistics do not perform better than the asymptotic tests in all situations. The bootstrap tests that are based on approximately pivotal statistics provide both adjustment of size and enhancement of power. These tests are therefore recommended for use in situations similar to those included in the simulation study.     

中国人口学科国际化水平及其影响因素

国际化是学科成熟与发展的一个重要指标。但是作为世界人口第一大国,中国人口学科的国际化并没有发展到一个相对应的水平。在界定了学科国际化概念的基础上,借助问卷调查数据来分析中国人口学科国际化的现状,探讨中国人口科学继续与国际学界融合所面临的困难及其主要原因。结果表明,中国人口学的国际化明显处于不断萎缩的态势,其直接动因和深层次缘由分别是整个人口学界的国际化意识与能力的减弱,以及人口学科文化与制度本身存在的缺陷。加强国际化的学科文化建设与建立相配套的学科制度是提高中国人口学科国际化水平的重要途径。     

Issues in Second Language Acquisition

Input plays an important part in the acquisition of second language.This report will just focus on Krashen＇s Input Hypothesis and Long＇s Interaction Hypothesis concerning input.First a summary will be made about the two theories,and then the writer will make a comparison between the two.This report will conclude with the writer＇s observations of how her thinking about ＇input＇ has been clarified in the process of preparing and writing this report.     

朝鲜族人口自然增长率下降对发展的影响

本文分析了朝鲜族人口减少的主要原因及负面影响,并提出了解决的对策.     

试论城市化进程中的民族关系--以对临夏市的调查为视点

临夏市作为西北民族地区的一个小城市,在城市化进程中,其民族关系也会受到影响.针对临夏市的实际情况及学术界的研究现状,我们选取临夏市城市化进程中变化较大的几个变量,即民族居住格局的变迁、人口流动的影响、民族通婚的增减以及宗教因素,作为研究重点来衡量城市化进程中的民族关系.在此基础上得出临夏市各民族之间的关系总体上是平等、团结、互助、合作的社会主义新型民族关系,和谐平等的民族关系占据了主导地位的结论,并归纳出城市化进程中临夏市的民族关系具有主从性、敏感性、易发性、历史性、隐蔽性、复杂性等特点,最后提出临夏市各族群众必须解决自身的定位问题,建立临夏市和谐民族关系的良性运转机制.