摘要:

The multidimensional runs statistic for testing the homogeneity of two multivariate samples is equivalent to the number of linked between-sample pairs of observations. Two observations may be linked if they are “close” to each other — for example, if joined by an edge of the minimum spanning tree, or if within a specified distance or “tolerance”. Based on the results of computer simulation of normally distributed data, we compare the multidimensional runs test with Hotelling's T2, showing that under certain circumstances the runs test can detect location differences with greater power. We also present guidelines for choosing a tolerance, expressed indirectly in terms of choosing what proportion of within-sample pairs to link so as to maximize power. These guidelines generally lead to a much higher proportion of linked pairs than would be given by any small number of orthogonal minimum spanning trees.

ISSN:0361-0918    

DOI:10.1080/03610918508812422

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

This paper considers a computational method for analysing growth curve data with missing values. We present an algorithm which is often referred as the EM algorithm. The procedure proposed here utilizes the technique of analysis of covariance.

ISSN:0361-0918    

DOI:10.1080/03610918508812423

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

Asymptotic Relative Efficiencies (ARE) of the robust coordinatewise M-estimators with respect to the robust Maronna-type M-estimators proposed by Singer and Sen (1985) are computed under different elliptically symmetric error distributions. ARE of robust coordinatewise M-estimators with respect to Normal Maximum Likelihood (NML) estimators are also computed under a more general bivariate underlying distribution. The results indicate that the Maronna-type M-estimator is only slightly more efficient than the coordinatewise one, except for extreme cases like the Cauchy or for large dimensionalities where the gain in efficiency may be considerable. Both types of M-estimators perform better than the NML estimators for the proposed departures from normality. For distributions not of the elliptically symmetric type, Maronna-type estimators are not suitable, and hence, the comparison is not of real interest.

ISSN:0361-0918    

DOI:10.1080/03610918508812424

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

In this paper, a modified binomial distribution is suggested to cope with situations in which some of the frequencies of a binomial distribution are not distinguishable from others, or the number of occurrence of the event is bounded by a number which is less than the total number of trials. Maximum likelihood estimator, moment estimator, and other estimators of the proportion parameter p are considered.

ISSN:0361-0918    

DOI:10.1080/03610918508812425

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

This paper provides a new table of critical values for testing q linear contrasts in a repeated measures design.In contrast to some tables, nothing is assumed about the structure of the variance-covariance matrix. The new table is more exten-sive and slightly better than existing tables where the critical values are based on the Bonferroni inequality.

ISSN:0361-0918    

DOI:10.1080/03610918508812426

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

A maximum likelihood solution is presented for analyzing data which arise from a linear model whose error term is assumed to have variance proportional to some unknown power of the response. An efficient iterative method for solving the likelihood equations is obtained which incoporates use of a transfomation to orthogonalize the two variance paramaters. Assessments of the method are made through simulations study and the results are compared with those of the ordinary least squares. Examples from the literature are included to illustrate the method and also to compare the results with a weighted least squares estimates.

ISSN:0361-0918    

DOI:10.1080/03610918508812427

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

Response variances, var(yi), are estimated using replications for each experimental condition. The resulting estimated variances can be used to derive the correct variances of the Ordinary A 2 Least Squares (OLS) estimators β. The estimates si can also be used to compute the Estimated Weighted Least Squares (EWLS) estimators β*. The asymptotic covariance formula for EWLS might be utilized to test the EWLS estimators. The type I and type I1 errors of this test procedure are compared to the corresponding A errors for the OLS estimators β.

ISSN:0361-0918    

DOI:10.1080/03610918508812428

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

Let X1,…X,khave a joint k-variate normal distribution with zero means, common unknown varianceσ2and known correla- tion matrix (ρij) where ρij= ρ for all i ≠ j. Let s2be distributed independently of the X1such that vs2/σ2has a chisquared distribution with v degrees of freedom. New tables with wider coverage and more accuracy than the previously published ones are given for the percentage points of. Some basic theoretical results are given in Section.

ISSN:0361-0918    

DOI:10.1080/03610918508812429

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

A study is carried out of a sampling from a half-normal and exponential distributions to develop a test of hypothesis on the mean. Although these distributions are similar, the corresponding uniformly most paerful test statistics are different. The exact distributions of these statistics my be written in terms of the incomplete gamma function. If the experimental data my be fitted by either distributions, it is advisable to carryout the test based on the half-normal distribution as it is generally more powerful than the one based on the exponential one.

ISSN:0361-0918    

DOI:10.1080/03610918508812430

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor

摘要:

Motivated by two problems occuring in the biological sciences, Wallgren (1980) recently derived the exact distribution of the product of two correlated t variates. The purpose of this paper is to provide a table of exact percentage points so that the solution proposed by Wallgren can be applied. An approximation of the distribution is also proposed and evaluated.

ISSN:0361-0918    

DOI:10.1080/03610918508812431

出版商:Marcel Dekker, Inc.    

年代:1985

数据来源: Taylor