Sample Size and Power Calculation in Comparing Diagnostic Accuracy of Biomarkers with Pooled Assessments

When testing of a biomarker is costly, pooling of samples becomes a useful and efficient alternative (Faraggi et al., 2003). In this paper, we develop procedures for sample size and power calculations for planning a study comparing the accuracy of biomarkers in diagnosis of diseases with pooled samples. Explicit formulas are derived for several important pooling strategies. The effects of pooling samples on sample size and power of the test are also discussed.     

西方贸易与环境理论的演化及新发展

20世纪70年代以来,贸易与环境问题就开始成为国际关注的问题,贸易自由主义者和环境保护主义者就此从未停止过争论。文章主要对其争论的主要领域进行了总结,对自由贸易和环境保护之间的关系进行了评述,希望能对我国更好地开展自由贸易提供一些借鉴。     

The assessment of tumour response to treatment

Summary.  A parsimonious model for treated tumours is developed as a continuation of our previous work on regrowth curve theory. The statistical model belongs to the family of marginal non-linear models since the only linear parameters of the model are tumour specific and random facilitating parameter estimation. An important feature of the model is that it enables the estimation of the fraction of cancer cells surviving the treatment in vivo having easy-to-obtain longitudinal measurements of tumour volume. We compare several methods of estimation, including Lindstrom–Bates, iterated reweighted least squares and maximum likelihood. The last two methods are computed via the total estimating equations approach and variance least squares. The theory is illustrated with a photodynamic tumour therapy example.     

Acceptance sampling based on truncated life tests for generalized Rayleigh distribution

This paper considers the problem of an acceptance sampling plan for a truncated life test when the lifetime follows the generalized Rayleigh distribution. For different acceptance numbers, confidence levels, and values of the ratio of the fixed experiment time to the specified mean life, the minimum sample sizes necessary to ensure the specified mean life are found. The operating characteristic values of the sampling plans and producer's risk are discussed. Some tables are presented and the use of the tables is illustrated by a numerical example.     

Objective Testing Procedures in Linear Models: Calibration of the p-values

Abstract.  An optimal Bayesian decision procedure for testing hypothesis in normal linear models based on intrinsic model posterior probabilities is considered. It is proven that these posterior probabilities are simple functions of the classical F -statistic, thus the evaluation of the procedure can be carried out analytically through the frequentist analysis of the posterior probability of the null. An asymptotic analysis proves that, under mild conditions on the design matrix, the procedure is consistent. For any testing hypothesis it is also seen that there is a one-to-one mapping – which we call calibration curve – between the posterior probability of the null hypothesis and the classical bi p -value. This curve adds substantial knowledge about the possible discrepancies between the Bayesian and the p -value measures of evidence for testing hypothesis. It permits a better understanding of the serious difficulties that are encountered in linear models for interpreting the p -values. A specific illustration of the variable selection problem is given.     

科学决策研究——效用理论与房地产项目决策实例分析

房地产项目开发中决策缺乏科学性操作,给项目造成潜在风险。科学决策的规范运用使项目风险降低,成功概率大大提升。效用理论作为科学决策的重要基本理论,在决策领域发挥着重要作用。采用历史观的方法,对效用理论的创立、发展及改进进行了研究。通过对现代效用理论在房地产中基本应用的探讨,建立项目决策的效用公式,并进行了效用决策的实例分析。     

洗衣机发展预测模型及应用

我国洗衣机的生产发展十分迅速,从1978年的年产400台到1985年的883万台,八年间增长二千多倍,今后的生产发展前景如何?运用本文介绍的一种预测模型,可以求得公元2000年以前每年洗衣机需求量的预测值,并求得1983年8月至1991年1月为洗衣机生产发展的成熟时期,该模型亦可用于其它耐用消费品的生产发展预测,所得结果可供有关部门决策时参考。     

饱和增长趋势预测的自适应方法

讨论了商业、市场中大量存在的饱和增长过程的自适应预测问题,详细分析了自适应增长趋势预测尤其是Kalman滤波方法涉及的模型、模型变换、递推初值确定及趋势外椎等技术问题。     

Abel分部求和公式与排序定理

Ａｂｅｌ分部求和公式与排序定理王慧兴众所周知，排序定理在不等式的证明和最优化设计方面发挥着出奇制胜的作用。本文运用Ａｂｅｌ分部求和公式给出排序定理一个新证明，因而排序定理可作为Ａｂｅｌ分部求和公式的一个推论，进而开拓Ａｂｅｌ分部求和公式在中等数学中的...     

收敛函数列的曲线收敛与弧长收敛

本文系统讨论了收敛函数列的曲线收敛与弧长收敛,并给出和证明了弧长收敛的一个性质定理和一个判定定理。