The Multilevel Approach to Repeated Measures for Complete and Incomplete Data

Repeated measurements often are analyzed by multivariate analysis of variance (MANOVA). An alternative approach is provided by multilevel analysis, also called the hierarchical linear model (HLM), which makes use of random coefficient models. This paper is a tutorial which indicates that the HLM can be specified in many different ways, corresponding to different sets of assumptions about the covariance matrix of the repeated measurements. The possible assumptions range from the very restrictive compound symmetry model to the unrestricted multivariate model. Thus, the HLM can be used to steer a useful middle road between the two traditional methods for analyzing repeated measurements. Another important advantage of the multilevel approach to analyzing repeated measures is the fact that it can be easily used also if the data are incomplete. Thus it provides a way to achieve a fully multivariate analysis of repeated measures with incomplete data. This revised version was published online in June 2006 with corrections to the Cover Date.     

2016年《情报科学》载文与引文统计分析

本文以2016年《情报科学》刊载文献为数据集,从文献题录信息与引文信息两个角度,运用数理统计方法,评价期刊的质量和学术水平。     

陕西县域植被覆盖与土地退化关系的研究

本文依据最新遥感影像和多种统计资料,分别计算了陕西省96个市县植被覆盖与土地退化指数。采用全样本统计和典型剖面分析的方法,对陕西县域植被覆盖和土地退化的关系进行了分析,结果显示:(1)植被覆盖与土地退化有着极为密切的关系,随着植被覆盖指数的降低,土地退化呈明显的加重趋势,植被覆盖≤20%为其临界值;(2)在湿润指数≤1.2的关中平原和汉江谷底,由于农业开发和城镇建设,植被覆盖与土地退化关系不甚明显。     

Exceptional Convergence of the Sample Variance

The case is investigated when Hoeffding's one sample U–statistic theorem for the sample variance S² is not applicable. It is shown that this occurs only when the parent distribution is the two–point distribution with jumps of equal magnitude. For this exceptional case the standardised S² is shown to converge in distribution to (1 – V )√2, where V has chi–square distribution with one degree of freedom.     

监理工程师对混凝土质量验收的数理统计方法

介绍了数理统计方法在深圳市某多层建筑混凝土质量控制中的运用,分析了监理工程师如何运用数理统计公式对混凝土进行质量控制和质量验收的方法．     

中国商务中心区区位分布研究

明确传统商务中心区与现代商务中心区的内涵,归纳商务中心区发展的三种模式,提出了理想的商务中心区发展模式是市场和政府有限引导共同作用的二元驱动模式。在世界范围内将商务中心区划分为四个等级,建立了建设和发展商务中心区满意度的评价指标体系。选择了26个有代表性的城市作为样本城市,采用聚类分析法,将样本城市划分为四大类别。提出了在中国现阶段商务中心区可能的区位分布是:上海、北京、广州和重庆,而其他城市的商务中心区可以考虑建设成为传统商务中心区。最后,进行了商务中心区合理布局的对策分析。     

Assessing the historical role of credit: Business cycles,financial crises and the legacy of Charles S. Peirce

This paper provides a historical overview of financial crises and their origins. The objective is to discuss a few of the modern statistical methods that can be used to evaluate predictors of these rare events. The problem involves the prediction of binary events, and therefore fits modern statistical learning, signal processing theory, and classification methods. The discussion also emphasizes the need for statistics and computational techniques to be supplemented with economics. The success of a forecast in this environment hinges on the economic consequences of the actions taken as a result of the forecast, rather than on typical statistical metrics of prediction accuracy.     

现行林业统计指标体系改革设想

随着我国经济社会的快速发展和林业建设领域的不断拓宽,现行的林业统计指标体系迫切需要进一步调整和完善。论述了林业统计指标体系的建立及发展历程,客观分析了现行林业统计指标体系中存在的问题及成因,提出了改革的总体设想及相关的保障工作。     

美国行政中心空间与规模特征及其成因研究

行政中心是行政区划的基本要素之一,行政中心尽量靠近地理中心对行政管理和促进区域发展平衡有积极的理论和现实意义。文章提出了行政中心与地理中心偏差的计算公式,运用空间统计分析方法结合Ar-cGIS软件,以美国为例,分析了美国县治与地理中心地理偏差的空间分布和数据特征以及州府与州最大城市的人口规模关系特征,总结了产生以上特征的自然、历史和政治上的原因,并运用空间可视化方法直观地显示分析结果。分析结果表明：①美国的县治普遍比较接近地理中心,其接近程度有由东部向西部递减的趋势且存在一定的空间集聚;②州府大多数并非州最大城市,人口较少。最后从行政中心区位选择和区域发展平衡两方面得出对中国的启示,为中国行政区划改革和区域经济发展提供借鉴。     

抽样调查中无回答误差的分析与调整

分析无回答误差产生的原因和影响,在抽样调查的过程中,结合市场调查的次序和方式采取无回答误差的预防措施。对已经产生无回答的数据,用样本替代法和加权调整法对缺失数据进行调整,这两种方法都提高了调查数据的可靠性和准确性,有效降低无回答率。