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贝叶斯同时估计中的序贯分配与可选停止AI 解读

Suppose random variables X 1, X 2, …, with distribution depending on parameter θ1, are observable from population 1, independent of random variables Y 1, Y 2, …, with distribution depending on parameter θ2, and observed from population 2. The simultaneous estimation of parameters θ1 and θ2 is of interest. An experiment is conducted where at each stage either an X or a Y is observed, and the experiment may be stopped at any stage (allocation and decision depending on…

右删失观测下尺度变化的非参数估计AI 解读

Nonparametric point and interval estimators of the ratio of two scale parameters are given for arbitrarily right-censored data based on the idea of Hodges and Lehmann (1963). These estimators are defined in terms of rank test statistics for testing the equality of two survival distributions. The asymptotic properties and efficiencies of estimators corresponding to the tests studied by Gill (1980) are investigated.

第二类删失下局部最强秩检验的统一处理AI 解读

For the derivation of locally most powerful (LMP) rank tests, a general method that encompasses a wide variety of testing problems and type II censoring schemes is formulated. Applications are illustrated in the context of the one-sample, two-sample, and regression problems. It is shown that the traditional derivations of the LMP rank tests are greatly simplified with the proposed method. The LMP criterion is also applied to some problems for which only ad hoc tests were…

二维表的低中位数与最小绝对残差分析AI 解读

Some properties of and extensions to Tukey's method of median polish, an exploratory robust additive decomposition of a two-way table, are presented using the low median. If the table entries are rational numbers, then the iteration process must stop after a finite number of steps. However, even for tables of bounded dimension the number of iterations can be arbitrarily large. For 3 by 3 tables, the sum of absolute residuals is often minimized by median polish. Minimization…

随机配对的检验AI 解读

The analysis of contingency tables in which both margins have the same polychotomy is considered. These tables arise when members from categories form pairs. Pairs cannot be between members of the same category. Appropriate models for pairing are introduced. A maximum likelihood algorithm is developed and asymptotic covariance formulas are derived. An empirical example illustrates the procedures.

结合人类与其他物种癌症研究结果的贝叶斯方法AI 解读

We propose a class of Bayesian statistical methods for interspecies extrapolation of dose-response functions. The methods distinguish formally between the conventional sampling error within each dose-response experiment and a novel error of uncertain relevance between experiments. Through a system of hierarchical prior distributions similar to that of Lindley and Smith (1972), the dose-response data from many substances and species are used to estimate the interexperimental…

儿童死亡后的生育反应：最大似然估计模型AI 解读

The individual household's fertility response to an experienced child death, the replacement probability, is estimated for Brazil using a maximum likelihood estimation model. This model, which treats births, deaths, and replacement births as endogenous and which assumes discrete distributions for these random variables, avoids the statistical problems of earlier estimates. The model allows the distribution of births, deaths, and replacement births to vary with included…

方差成分 MINQUE 估计量的计算方法AI 解读

The original expression for MINQUE estimators of variance components involved the inverse of a matrix whose dimensions equalled the total sample size. Later papers described more practical methods of computing the estimators. In this article a method is described that involves matrices and vectors with dimensions no larger than the number of nonempty cells.

卷积分布参数的最大似然估计AI 解读

In the present age of computer sophistication, computational difficulty is no longer a justification for seeking alternative and inefficient estimation procedures in place of maximum likelihood estimation, particularly when there are only two or three parameters to be estimated. Convolution densities are an example where this has occurred. It is shown that in a large class of such densities, the maximum likelihood equations can be reduced by one. Thus for a two-parameter…

用于多行多列列联表 Fisher 精确检验的网络算法AI 解读

An exact test of significance of the hypothesis that the row and column effects are independent in an r × c contingency table can be executed in principle by generalizing Fisher's exact treatment of the 2 × 2 contingency table. Each table in a conditional reference set of r × c tables with fixed marginal sums is assigned a generalized hypergeometric probability. The significance level is then computed by summing the probabilities of all tables that are no larger (on the…

信息度量与贝叶斯层级模型AI 解读

We consider the Bayesian statistical models in which the prior distribution of the parameter vector θ1 in the distribution of an observable random vector X is to be specified in a hierarchical fashion and one wants to learn about the hyperparameters at each level of this prior distribution. It is shown that for a wide class of information measures, based on the so-called f divergence, the information decreases as one moves to higher levels of hyperparameters. This result…

Hunter 同时推断方法及其在高相关已知结构中的应用AI 解读

The Hunter (H) method of simultaneous estimation of all means is based on a second-order Bonferroni-type inequality and is superior to the Bonferroni (B) method. This method is applicable for cases using a multivariate t distribution with correlation matrix R = (ρ ij ) and is shown to be decidedly superior to the B method when the correlations ρ ij in R are all large (|ρij| > .5). This article presents an example, using data from Draper and Smith (1966), in which the 95…

删失数据下的相对风险估计AI 解读

We investigate a class of nonparametric estimators of relative risk in the two-sample case of the proportional hazards model for censored data. The asymptotic distribution of these estimators is derived using influence functions. The optimal estimator in this class has the same influence functions and the same asymptotic distribution as the maximum partial likelihood estimator of Cox (1972). The behavior of the influence functions is discussed briefly, and the last section…

预测规则错误率的估计：对交叉验证的改进AI 解读

We construct a prediction rule on the basis of some data, and then wish to estimate the error rate of this rule in classifying future observations. Cross-validation provides a nearly unbiased estimate, using only the original data. Cross-validation turns out to be related closely to the bootstrap estimate of the error rate. This article has two purposes: to understand better the theoretical basis of the prediction problem, and to investigate some related estimators, which…

自回归误差回归模型预测的小样本性质AI 解读

Monte Carlo methods are used to examine the small-sample properties of various estimators of asymptotic prediction variance (APV) from the regression model with autoregressive errors. Two practical estimators of APV, one of which includes terms reflecting parameter estimation and one of which excludes these terms, are compared to the mean squared error of prediction for regression models with different autocorrelation of the errors, different sample sizes, and different…

临床化学中污染正态分布的估计方法AI 解读

Mixtures of normal distributions have been used in modeling a wide variety of experimental data in fields as different as fisheries biology and medicine. A problem in the field of nutrition concerning estimation of the population proportion of anemic individuals from a sample of hemoglobin values has led to consideration of a class of mixtures of two components, where only the predominant component is assumed to be normal. The second component is assumed to contaminate only…

结合历史与随机化对照评估比例趋势AI 解读

A statistical method for incorporating historical control data in the analysis of proportions is proposed and illustrated. The method has as its extremes logistic regressions completely pooling and completely ignoring historical controls. The degree of pooling used is determined by the variability from experiment to experiment in the control incidences. The fit of historical control groups to an assumed normal logistic model is assessed using probability plotting techniques.…

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非参数地统计学AI 解读

Photoset in Malta by Interprint LtdFar better an approximate answer to the right question which is often vague, than an exact answer to the wrong question

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具有共同线性部分的线性模型中协方差误设下的线性估计AI 解读

The linear model (Y, Xβ, V), where X is any matrix satisfying the conditions ℛ (U) ⊂ ℛ (X) and ℛ (A′) ⊂ ℛ (X′), is considered, U and A being known matrices and ℛ (·) denoting range space. Nonnegative definite matrices V, for which every linear representation or some linear representation of the BLUE of Aβ under (Y, Xβ, V 1) continues to be its BLUE under (Y, Xβ, V) for every such matrix X, are characterized. Conditions under which estimable linear parametric functions admit…