Bootstrapping rank statistics

The bootstrap, which provides powerful approximations for many classes of statistics, is studied for simple linear rank statistics employing bounded and smooth score functions. To verify consistency we view a rank statistic as a statistic induced by a statistical functional ψ which is evaluated at a pair of dependent signed measures. Thus, we can apply the von Mises method to verify asymptotic results for the bootstrap. The strong consistency of the bootstrap distribution estimator is derived for the bootstrap based on resampling from the original data. Further, the residual bootstrap is studied. The accuracy of the bootstrap approximations for small sample sizes is studied by simulations. The simulations indicate that the bootstrap provides better results than a normal approximation.     

A central limit theorem for sums of correlated products

Consider a sequence of random points placed on the nonnegative integers with i.i.d. geometric (1/2) interpoint spacings y _i . Let x _i denote the numbers of points placed at integer i . We prove a central limit theorem for the partial sums of the sequence x ₀ y ₀, x ₁ y ₁, . . . The problem is connected with a question concerning different bootstrap procedures.     

Generalized M-fluctuation tests for parameter instability

A general class of fluctuation tests for parameter instability in an M-estimation framework is suggested. Tests from this framework can be constructed by first choosing an appropriate estimation technique, deriving a partial sum process of the estimation scores that captures instabilities over time, and aggregating this process to a test statistic by using a suitable scalar functional. Inference for these tests is based on functional central limit theorems, which are derived under the null hypothesis of parameter stability and local alternatives. For (generalized) linear regression models, concrete tests are derived, which cover several known tests for (approximately) normal data but also allow for testing for parameter instability in regressions with binary or count data. The usefulness of the test procedures—complemented by powerful visualizations derived from these—is illustrated using Dow Jones industrial average stock returns, youth homicides in Boston, USA, and illegitimate births in Grossarl, Austria.     

现浇空心楼盖GBF管质量检查及抽样方法探讨

GBF管的质量检查和验收是现浇空心楼板质量控制的关键,包括GBF管材料、制作和施工等多方面内容,而抽样检测又是GBF管质量检查验收的重要手段,本文对监理工程师基于空心楼板GBF管质量检查的内容及抽样检测方法进行了分析和探讨。     

The median of the poisson distribution

The purpose of this paper is twofold: first, to provide a closed form expression for the median of the Poisson distribution and, second, to improve the known estimates of the difference between the median and the mean of the Poisson distribution. We use elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit TheoremReceived November 2002     

An application of Stein’s method to limit theorems for pairwise negative quadrant dependent random variables

Stein’s method is used to derive an error in normal approximation for sums of pairwise negative quadrant dependent random variables, but under the assumption of second moment only. This allows us to derive a central limit theorem for pairwise negative quadrant dependent random variables with Lindeberg’s condition. Research supported by Science Foundation of Zhejiang Provincial Education(no. 20060122)     

土工实验中的液、塑限测定浅议

文章分析了当前土工实验中的液、塑限测定过程中应当注意的问题及其存在的问题,并论述了如何对其实验数据进行处理和分析的方法。     

公司并购绩效评价最基本的实证方法研究

企业并购绩效评价的结果是否能真实地反映出并购企业的绩效实际,关键在于绩效评价方法的选择。股票市场事件研究法和经营业绩对比研究法是两种最为基本的实证方法,分析总结和掌握其方法的使用、适用范围和应注意的问题等,对公司并购绩效做出客观评价尤为重要。     

微分中值定理中辅助函数构造的方法

通过对微分中值定理的应用研究,发现在解决此类命题中,大多采用构造辅助函数的方法来证明,如何构造辅助函数成为证明此类问题的关键。本文给出了三类关于辅助函数的构造的方法和技巧,并给出例题并加以应用。     

拓宽中小企业融资渠道的新方式——项目融资

融资难问题一直是制约中小企业发展的最大障碍。针对这一问题,本文首先对我国780家中小企业进行抽样调查,从中小企业目前的融资方式和政府应对中小企业融资难采取的举措两个方面分析我国中小企业融资现状;然后结合项目融资特点,利用模糊综合评判方法,对中小企业管理项目的能力进行分析,并且结合具体企业进行实例验证,论证了项目融资可以作为拓宽中小企业融资渠道的方式;最后对中小企业项目融资问题提出了政策、决策和方法等方面的有关建议。     

“工程力学”在工作过程系统化课程开发中的探索与实践

工作过程系统化的课程改革,是当今高等职业教育课程改革新的趋势。"知识的总量未变,知识排序的方式发生变化",正是对这一新的职业教育课程开发方案中所蕴涵的革命性变化的本质概括,也是课程开发的全新理念。本文论述的是高职高专院校工作过程系统化课程改革中"工程力学"课程内容编排的总体设计理念和方式、教学方法的创新、教材建设、实训条件建设等教学各方面积累的一些经验。     

铁路单洞双线隧道斜井与正洞上断面相交时交叉口加固及挑顶施工技术

本交叉口加固及挑顶施工技术是一种主要适用于铁路单洞双线隧道斜井与正洞上断面相交时的施工方法。文章详细介绍斜井与正洞上断面相交时的施工方法和施工工艺流程,为铁路单洞双线隧道斜井与正洞上断面相交的施工提供借鉴和技术支持。     

产品贮存可靠性数据收集和处理方法及贮存失效率预测模型的建模方法研究

针对库存产品的质量管理,根据国内外有关资料的论述,通过对数据收集、数据处理方法、建立贮存失效率预测模型的研究,提出贮存可靠性数据收集和处理及建立贮存失效率预测模型的一般方法。