二维粒子分布均匀度测算方法研究

本文对定量表达平面上粒子分布均匀程度的测算方法进行了研究,提出了形态定量中二维粒子分布均匀度的新概念,并导出相应计算公式中为二维粒子均匀度,SDd为平面上任意两个相邻粒子间间距(d)的标准差,X为d的均值,CV为d的变异系数,此外还相应提出了误差大小计算公式和控制方法,对二维粒子分布均匀度的意义及有关问题进行了讨论。     

Homogeneity Test of Difference Between Two Correlated Proportions in Stratified Matched-Pair Studies

Stratified matched-pair studies are often designed for adjusting stratification factors in modern medical researches. This article investigates a homogeneity test of differences between two correlated proportions in stratified matched-pair studies. We propose three test procedures, including an asymptotic test, bootstrap test, and multiple comparison procedures, and determine sample size requirements for such tests in a stratified matched-pair study. Simulation studies are conducted to evaluate the performance of the three test procedures and the accuracy of our derived sample size formulas. Empirical results show that (1) the likelihood ratio statistic is robust, while the score statistic and the modified score statistic are conservative in some cases of our considered settings; (2) the likelihood ratio statistic and the score statistic with the bootstrap method and the MaxT procedure behave satisfactorily in the sense that their type I error rates are close to the pre-given significance level; and (3) the derived sample size formulas are rather accurate. A real example from a clinical laboratory study is used to illustrate the proposed methodologies.