论文检索

摘要暂缺

对数秩检验中 Mantel–Haenszel 方差的适当性AI 解读

A challenge by Brown (1984) of the Mantel-Haenszel variance for the log rank test is dismissed as due to the nonasymptotic situation considered by Brown. Where the censoring mechanism in a time-to-response study could be influenced by treatment, the permutational variance is inappropriate and the Mantel-Haenszel hypergeometric variance must be used. If treatment is known or postulated to have no effect on the censoring mechanism, then use of the Mantel-Haenszel variance…

多参数情形下最大似然迭代程序的收敛问题AI 解读

In multiparameter situations there are important problems of convergence in the solution of maximum likelihood iterative equations. Convergence may be critically dependent on the initial parameter estimates employed. These problems are indicated specifically for a model of exponentially-distributed lifetimes where the reciprocal of the exponential parameter is linearly dependent on various regressor variables. A strategy is suggested based on alternative use of observed or…

多参数情形下最大似然迭代程序的收敛问题AI 解读

In multiparameter situations there are important problems of convergence in the solution of maximum likelihood iterative equations. Convergence may be critically dependent on the initial parameter estimates employed. These problems are indicated specifically for a model of exponentially-distributed lifetimes where the reciprocal of the exponential parameter is linearly dependent on various regressor variables. A strategy is suggested based on alternative use of observed or…

一自由度卡方检验：Mantel–Haenszel 方法的扩展AI 解读

A published method for analyzing multiple 2×2 contingency tables arising in retrospective studies of disease is extended in application and form. Extensions of application include comparisons of age-adjusted death rates, life-table analyses, comparisons of two sets of quantal dosage-response data, and miscellaneous laboratory applications as appropriate. Extensions in form involve considering multiple contingency tables with arbitrarily many rows and/or columns, where rows…

非线性参数函数的区间估计AI 解读

Suppose x 1 and x 2 are observations on a bivariate normal distribution with known variance matrix Σ and unknown means vector (μ1, μ2). Suppose an interval estimate of f(μ 1, μ2), is desired with 1 – α confidence. Let an interval estimate be obtained as [min f(μ1, μ2), max f(μ1, μ2)] subject to [(x 1 – μ1) (x 2 – μ2)] Σ−1[(x 1 – μ1)(x 2 – μ2)]′ ≤ R 2. It is shown that under certain conditions on f(μ1, μ2) and Σ, R need be taken only slightly larger than x 1(α), the value of…

摘要暂缺

非线性参数函数的区间估计AI 解读

Suppose x 1 and x 2 are observations on a bivariate normal distribution with known variance matrix Σ and unknown means vector (μ1, μ2). Suppose an interval estimate of f(μ 1, μ2), is desired with 1 – α confidence. Let an interval estimate be obtained as [min f(μ1, μ2), max f(μ1, μ2)] subject to [(x 1 – μ1) (x 2 – μ2)] Σ−1[(x 1 – μ1)(x 2 – μ2)]′ ≤ R 2. It is shown that under certain conditions on f(μ1, μ2) and Σ, R need be taken only slightly larger than x 1(α), the value of…

极大似然法计算剂量反应曲线的若干新方面AI 解读

The estimation of the parameters of dosage response curves by the standard probit method is an iterative process beginning with approximations to the parameters and using one or more cycles of computations to “improve” these estimates until they converge. The present paper gives a table and method for computing the maximum likelihood solution which converges more rapidly than the standard probit method. A procedure is presented for obtaining more accurate initial…