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治疗后癌症患者生存曲线的双参数模型AI 解读

A two-parameter model for representing the survival curve of treated cancer patients is described. If PT is the proportion of the treated patients surviving to time T, and [Ptilde]T is the proportion of a normal population surviving to time T then the survival curve may be represented by: — PT/[Ptilde]T = c.e-loge c,e-βT , where c is the proportion cured and β is the asymptotic value as T approaches ∞ of the instantaneous risk of dying from cancer in the uncured group. The…

若干用于统计推断的图表AI 解读

The determination of sample size to meet certain probability requirements is a problem which often faces an experimenter when obtaining a confidence interval or testing a hypothesis. This paper includes some new graphs useful in selecting sample size and gives a reference to a new textbook which includes a number of other similar type graphs. The method of construction is explained in detail and examples are included.

Student t 检验的功效AI 解读

Tables are given which correspond to the power of various tests which use the Student t-distribution. Noncentrality parameters are given to 5 decimal places for tests which have Type I error equal to 0.050, 0.025, 0.010 and 0.005. Type II errors are covered as follows: 0.01, 0.05, 0.10 (0.10) 0.90. One-sided and two-sided tests are discussed.

探索性统计研究中的主成分回归AI 解读

Regression upon principal components of the percentage points of the income and education distributions for 1950 census tracts in the city of Chicago led to the estimation of “beta coefficient profiles” for television receiver and refrigerator ownership, for central heating system usage, and for a measure of dwelling unit overcrowding. The betas are standardized coefficients of regression of a dependent variable upon the proportions of families in the classes of the marginal…

m 依赖时间序列的若干非参数检验AI 解读

In the case of moving average schemes or what are termed the m-dependent stochastic processes, the successive observations in the series are not stochastically independent. As a result, the usual sign test, the test based on the rank correlation τ (for randomness against trend alternatives), and the test proposed by Moore and Wallis [9] and further developed by Goodman and Grunfeld [2] (for the comovement between two time series) are not valid and require some modifications.…

概率论在刑事物证分析中的应用AI 解读

This paper considers some problems in the probabilistic analysis of physical evidence in criminal investigations. Two basic assumptions are made: (1) That the number of persons or objects possessing a particular set of properties can be considered as a random variable, and (2) that it is possible to estimate the probability function of this random variable. Two models (one with and one without the assumption that the suspect is a random selection from the set of possible…

概率预测AI 解读

The posterior distribution for parameters of a data distribution is usually the major objective of a Bayesian statistical analysis. Relatively little attention has been given to the fact that either a prior or a posterior distribution implies a marginal distribution, which may be called a “predictive distribution,” for outcomes of any sample not yet observed. Predictive distributions have been mainly applied to design problems, such as determination of optimal sample size.…

计算机时代以前的分布抽样史及其对模拟的意义AI 解读

The use of simulation, as a technique for attacking difficult problems, has increased greatly with the availability of the digital computer. This is illustrated by the large number of references in Shubik's (1960) bibliography2 and in the large number of studies published since then. Simulation is essentially an extension of a technique known as empirical sampling, or distribution sampling, which has been used in the field of statistics for many years. The limitations of the…

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牧场草本植物重量组成的估计方法AI 解读

In this article a method is presented which provides an efficient technique for estimating herbage weight composition on range units. The estimator derives from a weighted regression of species weight on species cover, i.e., the proportion of ground area covered by foliage of the species. Use of the present method of estimation in conjunction with a “pin-frame” field sampling procedure results in quite substantial savings in sampling cost for given precision, compared to the…

按规模成比例的随机系统抽样中的方差估计AI 解读

Approximate expressions are given for the variance of two commonly used variance estimators when two units are selected from a stratum systematically with probability proportionate to size. The stability of the variance estimators is examined with the help of an example.

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双向分类混合模型设计的最小充分统计量AI 解读

This paper presents theorems which can be used to obtain sufficient and minimal sufficient statistics for the two-way classification mixed model design. Using the general linear hypothesis model Y=X τ+Z β+e the authors prove that the dimension of a minimal sufficient statistic is a function of the ranks of certain submatrices of Z×X. Minimal sufficient statistics are presented in tabular form for some two-way classification designs and some of the distributional properties…

同时受扰动与观测误差影响的自回归变量预测AI 解读

Past work on prediction formulas for time series, e.g., that of Wiener and Yaglom, has used powerful and general spectral techniques that result in integral formulas difficult to evaluate in practical cases. In this paper the more direct, less powerful approach developed by Muth produces useful and specific results for a broad class of cases that includes virtually every case of a higher order Markov process observed with error. The results provide plausible theoretical…

临床试验数据分析的贝叶斯方法AI 解读

A Bayesian logical probability approach is described and its advantages with respect to constructing prior distributions for Bayesian analyses are discussed. Some standard Bayesian distribution theory for categorized data is summarized. Data from an on-going experiment to compare the relative efficacy of four operative treatments for ulcer are used both to pinpoint some of the practical problems involved in clinical trials and to demonstrate the usefulness of Bayesian…

概率论在刑事鉴识中的应用AI 解读

This paper considers some problems in the probabilistic analysis of physical evidence in criminal investigations. Two basic assumptions are made: (1) That the number of persons or objects possessing a particular set of properties can be considered as a random variable, and (2) that it is possible to estimate the probability function of this random variable. Two models (one with and one without the assumption that the suspect is a random selection from the set of possible…

摘要暂缺

用于统计推断的若干图表AI 解读

The determination of sample size to meet certain probability requirements is a problem which often faces an experimenter when obtaining a confidence interval or testing a hypothesis. This paper includes some new graphs useful in selecting sample size and gives a reference to a new textbook which includes a number of other similar type graphs. The method of construction is explained in detail and examples are included.

摘要暂缺

治疗后癌症患者生存曲线的双参数模型AI 解读

A two-parameter model for representing the survival curve of treated cancer patients is described. If PT is the proportion of the treated patients surviving to time T, and [Ptilde]T is the proportion of a normal population surviving to time T then the survival curve may be represented by: — PT/[Ptilde]T = c.e-loge c,e-βT , where c is the proportion cured and β is the asymptotic value as T approaches ∞ of the instantaneous risk of dying from cancer in the uncured group. The…

协方差矩阵奇异时正态变量的条件均值与协方差AI 解读

This note gives formulas for conditional means and covariances—formulas which are valid even when the joint distribution is singular. The method is algebraic; it applies to any joint distribution for which independence and zero correlation are equivalent.

逐步回归估计的效率AI 解读

Much attention has been paid to bias of coefficients resulting from stepwise regressions. Looking at bias alone implies that stepwise estimates are inferior. However, using the criterion of relative mean square errors, it is shown for the two variable case that under certain circumstances, stepwise estimators are “better” than direct least squares estimators.

有效调查访员的识别AI 解读

In studies where validation data is not available, effective interviewers are identified on the basis of various measures of interviewing performance. Yet little is known about the validity of these measures. In the study reported, sample addresses were selected on a probability basis from the records of financial institutions and the holdings reported to the interviewer were compared with institution records for the day of the interview. The frequency with which an…