摘要:

For testing that the population correlations coefficientp Q, Tiku and Balakrishnan1986) developed a robust test. This test is extended here to situcitions where one wants to test that p p , p being a specified non-zero value of p. o o

ISSN:0361-0918    

DOI:10.1080/03610918708812627

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

A Bayesian decision rule about the number of different values of a discrete randomvariable is numerically tested by Monte Carlo experiments. Results are exhibited showing the percentage of correct decisions as well as the robustness of the rule.

ISSN:0361-0918    

DOI:10.1080/03610918708812628

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

The paper considers the problem of performing all pairwise comparisons of means ineach row of a two-way ANOVA. This problem arises in situations where an investigator is concerned about disordinal interactions. For the equal variance case the proposed procedure is based on an extension of Tukey's procedure. The new procedure requires percentage points of the “multivariate” Studentized range distribution, and a table of these percentage points is provided. For unequal variances, extensions of the Games and Howell (1976) technique as well as Dunnett's (1980) T3 and C procedures can be used. Simulation results suggest that these latter procedures perform in a manner similar to the situations studied by Dunnett. In particular, the extension of Dunnett's T3 procedure appears to be best, among the procedures studied, when the degrees of freedom areless than 50 for any treatment group. Otherwise, use the extension of Dunnetts C.

ISSN:0361-0918    

DOI:10.1080/03610918708812629

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

In analysis of variance the usual method of determining the sample size needed to detect a certain maximum deviation between population means (assuming common variances) with specified significance level and power, uses the operating characteristic curves of the non-central F distribution. These curves, however are quite restrictive with respect to significance level and the number of treatment groups. An alternative procedure for approximating the sample size is proposed which is adaptable to a much broader range of analysis of variance situations. Monte Carlo simulation of the new procedure indicates that it is a reasonable method of determining the sample size for the specified power.

ISSN:0361-0918    

DOI:10.1080/03610918708812630

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

Some properties are considered of two-sided 3-content tolerance intervals for a normal distribution. We are given the sample mean, x, and the sample standard deviation, s, computedfrom a random sample of size n from a N(l,az) distribution. The tolerance interval x ± ks will cover a proportion, 3, of the sampled distribution with (100)confidence. We consider the effect of sample size on the proportion of the population covered, using a criteria for measuring the precision of the coverage. We also give tables to enable the user to control this precision. 969

ISSN:0361-0918    

DOI:10.1080/03610918708812631

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

The Kaplan-Meier (KME) and the parametric maximum likelihood (MLE) estimators of the survival function are compared, when the sample contains several outliers and this was not detected. A measure of relative efficiency of the KME with respect to the MLE is computed by simulation for several sample sizes, percentages of censorship and proportions of outliers in the sample. Results for large sample size are compared with values obtained using approximations to asymptotic variance and bias of the MLE. Exponential and Weibull models are used throughout the paper, both under exponential censoring. The objective is to assess the effect of outliers, under different conditions, on the relative efficiency of the KME respective to the MLE for those popular failure time distributions, in particular when the sample size is finite. It is found that for Weibull samples the effect can be substantial but for exponential samples it is almost negligible.

ISSN:0361-0918    

DOI:10.1080/03610918708812632

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

In 1935, R.A. Fisher published his well-known “exact” test for 2x2 contingency tables. This test is based on the conditional distribution of a cell entry when the rows and columns marginal totals are held fixed. Tocher (1950) and Lehmann (1959) showed that Fisher s test, when supplemented by randomization, is uniformly most powerful among all the unbiased tests UMPU). However, since all the practical tests for 2x2 tables are nonrandomized - and therefore biased the UMPU test is not necessarily more powerful than other tests of the same or lower size. Inthis work, the two-sided Fisher exact test and the UMPU test are compared with six nonrandomized unconditional exact tests with respect to their power. In both the two-binomial and double dichotomy models, the UMPU test is often less powerful than some of the unconditional tests of the same (or even lower) size. Thus, the assertion that the Tocher-Lehmann modification of Fisher's conditional test is the optimal test for 2x2 tables is unjustified.

ISSN:0361-0918    

DOI:10.1080/03610918708812633

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

A simple linear algebraic algorithm to generate a basis of the null space of a given integral matrix is utilized to present a computer algorithm, which in general, is used to reduce the support size of a given design as in a theorem of FoodyHedayat (Theorem 4.1, 1977), and in particular, it is used to produce a basis for trades. The computations based on this algorithm is of order of a polynomial function.

ISSN:0361-0918    

DOI:10.1080/03610918708812634

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

ISSN:0361-0918    

DOI:10.1080/03610918708812635

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor

摘要:

We describe two sequential sampling procedures for Bernoulli subset selection which were shown to exhibit desirable behavior for large-sample problems. These procedures have identical performance characteristics in terms of the number of observations taken from any one of the populations under investigation, but one of the procedures employs one-at-a-time sampling while theother allows observations to be taken in blocks during early stages of experimentation. In this paper, a simulation study of their behavior for small-sample cases (n > 25) reveals that they canresult in a savings (sometimes substantial) in the expected total number of observations requiredto terminate the experiment as compared to single-stage procedures. Hence they may be quite usefulto a practitioner for screening purposes when sampling is limited.

ISSN:0361-0918    

DOI:10.1080/03610918708812636

出版商:Marcel Dekker, Inc.    

年代:1987

数据来源: Taylor