Homogeneity test, sample size determination and interval construction of difference of two proportions in stratified bilateral-sample designs

In stratified otolaryngologic (or ophthalmologic) studies, the misleading results may be obtained when ignoring the confounding effect and the correlation between responses from two ears. Score statistic and Wald-type statistic are presented to test equality in a stratified bilateral-sample design, and their corresponding sample size formulae are given. Score statistic for testing homogeneity of difference between two proportions and score confidence interval of the common difference of two proportions in a stratified bilateral-sample design are derived. Empirical results show that (1) score statistic and Wald-type statistic based on dependence model assumption outperform other statistics in terms of the type I error rates; (2) score confidence interval demonstrates reasonably good coverage property; (3) sample size formula via Wald-type statistic under dependence model assumption is rather accurate. A real example is used to illustrate the proposed methodologies.     

Sample size calculation for recurrent events data in one‐arm studies

In some exceptional circumstances, as in very rare diseases, nonrandomized one‐arm trials are the sole source of evidence to demonstrate efficacy and safety of a new treatment. The design of such studies needs a sound methodological approach in order to provide reliable information, and the determination of the appropriate sample size still represents a critical step of this planning process. As, to our knowledge, no method exists for sample size calculation in one‐arm trials with a recurrent event endpoint, we propose here a closed sample size formula. It is derived assuming a mixed Poisson process, and it is based on the asymptotic distribution of the one‐sample robust nonparametric test recently developed for the analysis of recurrent events data. The validity of this formula in managing a situation with heterogeneity of event rates, both in time and between patients, and time‐varying treatment effect was demonstrated with exhaustive simulation studies. Moreover, although the method requires the specification of a process for events generation, it seems to be robust under erroneous definition of this process, provided that the number of events at the end of the study is similar to the one assumed in the planning phase. The motivating clinical context is represented by a nonrandomized one‐arm study on gene therapy in a very rare immunodeficiency in children (ADA‐SCID), where a major endpoint is the recurrence of severe infections. Copyright © 2012 John Wiley & Sons, Ltd.     

基于卫星云图的视场坐标转化模型

利用卫星云图的灰度矩阵,可以换算出经纬度等信息,并由此对不同时刻的卫星数据进行有效的风矢度量。本文运用地心坐标系统,构建了几何模型,结合lagrange插值法给出了灰度矩阵元素行列号对应于经纬度坐标的换算公式;借助Matlab软件得出了灰度矩阵中对应行、列的经纬二维数组;并用Matlab将灰度矩阵转化为卫星云图,并添加经纬信息,统一坐标系统后用Matlab绘制海岸线。     

关于随机Gronwall不等式的一点注记

指出文献[5]中定理证明的错误,借助于一个引理,改进了该定理的证明．     

带Poisson跳随机Navier-Stokes方程解的指数稳定性分析

对随机Navier-Stokes方程的讨论,通常没有考虑Poisson跳对系统影响．在假设随机的外界环境对系统产生影响的条件下,给出了带Poisson跳的随机Navier-Stokes方程,利用连续鞅的性质,通过公式,Gronwall引理及广义的Gronwall扩展引理讨论了其解的指数稳定性,并给出了指数稳定性的充分条件。     

关于丢番图方程x2＋（x＋p）2=z2

从两个最基本的不定方程x2＋y2=z2和u2-2v2=p（其中p为奇素数）以及它们的相关定理出发,给出了不定方程x2＋（x＋p）2=z2的正整数解的通项公式.     

恩施土家族地区傩愿戏艺术语言的程式表现

以湖北省恩施土家族地区傩愿戏为观察解读对象,借用中国画以抽象的符号表现程式这一艺术语言表现形式对其进行文化阐释。认为恩施土家族傩愿戏在三段式表演中运用程式化符号表现出了独特的艺术语言特点,对其艺术语言研究有利于它的保护、传承及创新。