论文检索

列联表合并与生存分析中的最大最小效率稳健检验AI 解读

A test is the maximin efficiency robust test for a family of possible models underlying the data if no other test has higher minimum efficiency relative to the asymptotically optimum test for each model. Methods used to examine the efficiency robustness of rank tests for the two-sample problem are adapted to obtain maximin efficiency robust procedures for testing the equality of proportions across several 2×2 tables, for combining the results of tests for trend in several 2…

得分检验的诊断统计量AI 解读

This article provides exact and approximate expressions for the change in the score test on deletion of observations. Deletions of individuals and of entire risk sets from matched case-control and survival studies are discussed in detail. A simple formula is derived, which measures the contribution of individual strata to score tests based on combining several contingency tables. The diagnostic is illustrated by application to the Stanford heart-transplant data.

对 Bootstrap 置信区间的疑虑AI 解读

The percentile method and bias-corrected percentile method of Efron (1981, 1982) are discussed. When these methods are used to construct nonparametric confidence intervals for the variance of a normal distribution, the coverage probabilities are substantially below the nominal level for small to moderate samples. This is due to the inapplicability of assumptions underlying the methods. These assumptions are difficult or impossible to check in the complicated situations for…

有限总体置信区间的条件覆盖性质AI 解读

Standardized errors (Ť — T)/v 1/2 were calculated for both ratio and regression estimators in each of 10,000 simple random samples of n = 32 from each of six populations, using four different variance estimators. Graphs show how the percentage of intervals T ± 1.96 v 1/2 that fail to contain T changes as a function of the average value of the auxiliary variable in the sample. They reveal that (a) intervals using the variance estimators from standard linear regression theory…

频率多边形：理论与应用AI 解读

In this article I investigate the theoretical properties and applications of the frequency polygon, which is constructed by connecting with straight lines the mid-bin values of a histogram. For estimating an unknown probability density function using a random sample, the frequency polygon is shown to dominate the histogram with respect to the criterion of integrated mean squared error, achieving the same rate of convergence to zero of the integrated mean squared error as…

相互依赖专家的多变量概率评估AI 解读

When two or more information sources (“experts”) provide a decision maker with information on two or more random variables, the decision maker using Bayes's rule has an opportunity to (a) update a prior about the random variables and (b) calibrate the experts. (Calibration is the process of adjusting the decision maker's likelihood about the experts' assessments.) This article presents a model for this two-way process and specializes to the case in which the experts'…

后向再发生时间的生存分析AI 解读

Many surveys include questions that attempt to measure the time of the most recent occurrence of some event, for example, last visit to a physician. Although it is tempting to apply survival (failure-time) methods to such data, the conditions under which such applications are appropriate have not been apparent. In this article it is shown that standard methods may be applied when the data arise from certain well-known stochastic processes. Special procedures may be necessary…

具有不确定性的人口预测AI 解读

"Errors in population forecasts arise from errors in the jump-off population and errors in the predictions of future vital rates. The propagation of these errors through the linear (Leslie) growth model is studied, and prediction intervals for future population are developed. For U.S. national forecasts, the prediction intervals are compared with the U.S. Census Bureau's high-low intervals." In order to assess the accuracy of the predictions of vital rates, the authors…

聚类分析中正确分配率的估计AI 解读

A sample of multivariate observations is assumed to be drawn from a mixture of a given number of underlying populations. The mixture likelihood approach to clustering is used to allocate each individual in the sample to its population of origin on the basis of the estimated posterior probabilities of population membership. Estimation of the correct allocation rate is considered for individual populations as well as for the overall mixture by averaging functions of the…

有限数据下的州际迁移预测：人口—经济方法AI 解读

"The limitations of available migration data preclude a time-series approach of modeling interstate migration [in the United States]. The method presented here combines aspects of the demographic and economic approaches to forecasting migration in a manner compatible with existing data. Migration rates are modeled to change in response to changes in economic conditions. When applied to resently constructed data on migration based on income tax returns and then compared to…

能否识别高生产率员工？稀疏双向表的稳健分析AI 解读

Data from individual measurements of production in a manufacturing environment may be thought of as a two-way table indexed by worker and task. If there are many tasks, such a table will normally be sparse. Adjustment for task effects is important if workers are to be compared to one another, since any two workers may have no tasks in common. Three techniques are presented for the analysis of such sparse tables: table-stripe regression, rectangle ratios, and network scores.…

利用收入分类横截面数据估计电力需求的短期收入弹性AI 解读

This study uses the 1980 energy application survey conducted by Ontario Hydro to estimate a short-run or conditional demand for electricity model. Two-step inference procedures are developed to take account of the special nature of the data in which the income variable is recorded in categorical form. Comparisons of short-run income elasticities with other studies, using the complete information of income variable, are also made.

摘要暂缺

摘要暂缺

摘要暂缺

计数过程的统计分析AI 解读

1. One-Dimensional Counting Processes.- 1.1. Probabilities on (0,?].- 1.2. The definition of one-dimensional counting processes.- 1.3. Construction of canonical counting processes.- 1.4. Intensities for canonical counting processes.- 1.5. Martingale decompositions for canonical counting processes.- 1.6. Statistical models and likelihood ratios.- Notes.- Exercises.- 2. Multivariate Counting Processes.- 2.1. Definition and construction of multivariate counting processes.- 2.2.…

摘要暂缺

摘要暂缺

右删失配对数据位置差的分布无关估计AI 解读

Nonparametric point and interval estimators of location difference in matched pairs data with arbitrary right censorship are proposed, based on a generalized Gehan—Gilbert test (Wei 1980). The point estimator is shown to be asymptotically normal and strongly consistent. The limits of the corresponding interval estimator are readily computable. An example is also provided to illustrate the techniques to problems in survival data analysis.

秩删失数据的最大似然回归AI 解读

Linear regression is a common method for analyzing continuous, cardinal data, but it is inappropriate when the dependent variable is an ordinal ranking. The model proposed for analyzing these data sets is the general linear model u = Xβ + ε, where the rank of the dependent variable u is observed instead of its value. A description is given for a numerical algorithm to evaluate the likelihood function that is efficient enough to permit maximum likelihood estimation of…

This article provides exact and approximate expressions for the change in the score test on deletion of observations. Deletions of individuals and of entire risk sets from matched case-control and survival studies are discussed in detail. A simple formula is derived, which measures the contribution of individual strata to score tests based on combining several contingency tables. The diagnostic is illustrated by application to the Stanford heart-transplant data.

相关专家的多重概率评估AI 解读

When two or more information sources (“experts”) provide a decision maker with information on two or more random variables, the decision maker using Bayes's rule has an opportunity to (a) update a prior about the random variables and (b) calibrate the experts. (Calibration is the process of adjusting the decision maker's likelihood about the experts' assessments.) This article presents a model for this two-way process and specializes to the case in which the experts'…

聚类分析中正确分配率的估计AI 解读

A sample of multivariate observations is assumed to be drawn from a mixture of a given number of underlying populations. The mixture likelihood approach to clustering is used to allocate each individual in the sample to its population of origin on the basis of the estimated posterior probabilities of population membership. Estimation of the correct allocation rate is considered for individual populations as well as for the overall mixture by averaging functions of the…

利用横截面分组数据估计电力需求的短期收入弹性AI 解读

This study uses the 1980 energy application survey conducted by Ontario Hydro to estimate a short-run or conditional demand for electricity model. Two-step inference procedures are developed to take account of the special nature of the data in which the income variable is recorded in categorical form. Comparisons of short-run income elasticities with other studies, using the complete information of income variable, are also made.