摘要:

This article is concerned with quantifying and representing group differences when there are more variables than observations. In particular, canonical variate analysis when the data consist of curves sampled at many grid points is considered. A new method is proposed that involves replacing the usually singular within-groups variation matrix by a fitted matrix that is positive-definite. To obtain the fitted matrix, a class of models, along with associated estimation and model-selection procedures, is presented. The results are applied to experimental data designed to assess the usefulness of data from a portable field spectrometer for discriminating between usable farmland and farmland affected by salinity.

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485281

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Optimal designs and associated tables of probability points for comparing the variances ofpexperimental treatments with that of a standard treatment under the assumption of normality are presented. One-sided and two-sided alternatives are considered. The optimality criteria are those of maximizing the probability of declaring an experimental treatment variance to be smaller than, larger than, or different from that of the standard for a fixed total sample size and a fixed experimentwise error rate. Both small-sample and asymptotic results are given. It is shown that the proportion of observations assigned to the standard treatment for comparing variances in the limiting case is the same as that for comparing means. These optimal proportions are in some cases quite different for small samples.

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485282

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In developing quality-control procedures, a step-loss function has been used implicitly or explicitly to describe consumer perceptions about product quality. A quadratic loss function has been suggested by Taguchi as an alternative to the step-loss function in measuring the loss due to imperfect product quality (cost of acceptance). In this article, Bayesian analyses of the known-standard-deviation acceptance-sampling problem are described for both the step and quadratic loss functions with three cost components—cost of inspection, cost of acceptance, and cost of rejection. A normal prior distribution is used for the lot mean. Efficient procedures for finding minimum expected cost procedures are given. For a particular example, comparisons are made of how optimal sampling plans and costs computed under the two cost structures change as the form of the prior distribution and misspecification of its mean and variance are varied. Sensitivity analyses for both cost functions show that the optimal sampling plan is robust with respect to the form of the prior distribution, as well as to misspecification of its mean and variance, if the tail specification reasonably approximates that of a normal distribution.

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485283

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A conditional method for inferences on the shape parameter of a two-parameter gamma distribution is presented in this article. A simple numerical implementation of this conditional method is developed; this is a computer program that takes the observed data as input and produces the confidence distribution function for the shape parameter, which in turn provides approximate observed significance levels and confidence intervals for that parameter, as output. These approximations are extremely accurate even for very small sample size and are numerically simple and easy to obtain.

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485284

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485285

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485286

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485287

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485288

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485289

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:0040-1706    

DOI:10.1080/00401706.1992.10485291

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor