Prediction intervals for farima processes by bootstrap methods

In this paper we introduce a procedure to compute prediction intervals for FARIMA (p d q) processes, taking into account the variability due to model identification and parameter estimation. To this aim, a particular bootstrap technique is developed. The performance of the prediction intervals is then assessed and compared to that of stand­ard bootstrap percentile intervals. The methods are applied to the time series of Nile River annual minima.     

Large,But Adaptable? A Successful Population Policy and Its Long Term Effects

A restrictive population policy led to almost doubling the number of newborns from one year to another in Romania in the 1960s. Twenty years later, this large generation (of women) enters a marriage market with few eligible older mates, in a society where marriage is a must. In this article, I analyze this social experiment within the broader frame of the marriage squeeze/two sex models. Using various data from censuses and surveys, I argue that the marriage market is flexible even when is confronted with disproportionately large cohorts. If the social pressure toward marriage is strong, the marriage rates do not necessarily fall, but the mating age patterns change.

Engendering Government Budgets in the Context of Globalization(s)

This article considers the strengths and weaknesses of attempts to 'engender' government budgets in the context of globalization, drawing on my own personal engagement in such attempts, and on the work of many gender budget initiatives (GBIs) all around the world. GBIs have sought to improve the distribution, adequacy and impact of government budgets at national, regional and local levels; and to secure greater transparency in the use of public money; and greater accountability to women as citizens. Their spread has itself been an example of globalization, in this case the globalization of action for gender justice; facilitated by e-mail, the Internet and air travel; supported by international foundations and international development cooperation funds. But, it may be argued, GBIs have begun to engage with government budgets just at the time when governments, especially in the South, have less and less control over public finance decisions, due to other aspects of globalization. This article considers whether there is any point in GBIs if economic power lies in international markets, rather than in the Ministry of Finance, and draws on examples from a wide variety of countries.     

中国婚姻挤压研究的回顾与评述

通过对检索文献的分析，从婚姻挤压的现状、原因、测度和影响等几个方面对我国学者就婚姻挤压研究取得的成果进行了综述，回顾了主要的研究成果，指出了研究的不足之处，并对未来研究做出展望，笔者最后建议从人口安全与和谐社会这两个角度研究婚姻挤压问题。     

中德婚姻市场供需情况的比较研究

本文从概念、形成机制、度量方法、后果及其解决途径等方面探讨了婚姻挤压问题 ,考虑到婚姻挤压对婚姻寿命、初婚人数及其性别差异的影响而创立了婚姻寿命指数与初婚挤压指数两指标 ,提出了婚姻市场类型的划分标准。通过对中德两国婚姻市场的历史与现状的考察 ,揭示了中德两国婚姻挤压产生的原因、类型、差异和未来的变化趋势 ,并对如何化解中国未来婚姻市场的供求矛盾提出了对策与建议     

婚姻挤压对中国农村不同群体安全感的影响——基于全国百村调查数据的分析

中国的男性婚姻挤压问题,已成为目前社会转型期的“社会风险”之一,给包括不同婚姻状态下男女两性在内的社会各群体的安全感均带来不利影响,成为影响人口社会可持续发展的隐患。从个人微观层次分析婚姻挤压下农村各群体的安全感现状及婚姻挤压对不同年龄和地区的农村男性安全感的影响发现:农村大龄未婚男性群体的安全感最低,婚姻状况对个人的安全感具有显著影响,婚姻挤压对男性安全感的影响存在显著的时代差异以及地区差异。提高中国农村各群体的安全感需从根本上改善农村各群体的生存状况,统筹解决性别失衡引起的婚姻挤压问题,从国家政策与制度创新的层面关注婚姻挤压及农村各群体的安全感问题。     

间接挤压铸造浇口形状对充型形态的影响

在间接挤压铸造过程中,充型液面的稳定性是铸件质量的保证。以平板铸件为研究对象,利用专业铸造软件 ProCAST进行数值模拟,分析了不同浇口形状与液面稳定性的关系。结果表明：带扩张角的浇道充型效果明显优于直浇 道,且随着扩张角的增大,其充型形态越平稳,液面凸起也越小;双浇道的浇注系统其充型效果不佳,液面波动加剧。     

Recent European fertility patterns: Fitting curves to ‘distorted’ distributions

Recent patterns of fertility in Europe show marked differences between countries. Recent United Kingdom and Irish fertility curves show ‘distortions’ in terms of a ‘bulge’ in early age fertility, distinct from the smoother curves of other European countries. These patterns may not be adequately described by mathematical functions used by previous studies to model fertility curves. A mixture model with two component distributions may be more appropriate. The suitability of the simple and mixture Hadwiger functions is examined in relation to the fertility curves of a number of European countries. While the simple Hadwiger model fits recent period age-specific fertility distributions for some countries, others which display a ‘bulge’ in early age fertility require a mixture Hadwiger model. Some of the parameters of the Hadwiger models appear to be related to familiar demographic indices. The simple and mixture Hadwiger models appear useful in describing and comparing fertility patterns across European countries.     

AutoLISP在三维铸件网格自动剖分中的开发应用

在用ＡｕｔｏＣＡＤＲ１２的ＡＭＥ进行铸件三维实体几何造型的基础上，本文用ＡｕｔｏＬＩＳＰ开发了铸件网格快速自动剖分的应用程序，实现了对任意复杂形状铸件在三维方向进行任意大单元的自动网格剖分，经实际应用，得到非常满意的结果。     

气化模铸造碳钢铸件含碳量的变化

本文讨论气化模铸钢件合碳量变化的规律，包括表面增碳、表面脱碳和体积增碳等。试验表明，选择透气性良好的涂料，涂料厚度≤１．０ｍｍ，负压度０．０３～０．０４ＭＰａ，可将表面和体积增碳减少到０．０２％以下。