摘要:

summaryThe model‐based approach to estimation of finite population distribution functions introduced in Chambers&Dunstan (1986) is extended to the case where only summary information is available for the auxiliary size variable. Monte Carlo results indicate that this ‘limited information’ extension is almost as efficient as the ‘full information’ method proposed in the above reference. These results also indicate that the model‐based confidence intervals generated by either of these methods have superior coverage properties to more conventional design‐based confide

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00493.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryThe paper discusses practical issues that arose in estimating a Linear model subject to heteroscedasticity, skewness and multicollinearity. The context of the problem required that linearity of the model as originally formulated be preserved. A seemingly satisfactory fit was obtained using a Gamma model and principal components.

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00494.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryVariance component estimates from a simple hierarchical model are used to model the distribution of large data values exceeding a threshold. The advantages of interrelating the components of variance and the exceedances are stressed. The theory is outlined and an analysis of some data on blood pressure is discussed.

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00495.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryIn this paper we examine the consequences, for statistical analysis and interpretation, of the particulate nature of radioactive contamination of a nuclear weapons test site. We propose a probabilistic model which incorporates the particulate nature of the contamination and which is simple enough to be statistically fitted to the data. Parameter estimation involves the reconciliation and combination of measurements of (a) 59.5 ke V gamma rays from americium‐241, a decay product of plutonium‐241, using a portable medium resolution NaI detector, on a regular survey grid at a test site and (b) 59.5 ke V radiation from soil samples obtained at grid points. The implications of the model for measurement of levels of contamination are conside

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00496.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryIn a previous analysis of data from a smallpox epidemic in Abakaliki, Nigeria, it was found that the epidemic model based on uniform mixing was able to give an adequate description only when the infection rate was taken to be a function of time. Here we demonstrate that an alternative, and plausible, explanation is that the infection rate acting upon each given susceptible is constant over time, but that it varies between susceptibles. This variation in susceptibility of individuals can give the impression that the infection rate is declining over time, because highly susceptible individuals tend to be infected earlier so that the mean susceptibility of the remaining susceptibles is declining over time.The above example reveals that there is interest in exploring the nature of the dependence of the infection rate upon time. To this end we propose the nonparametric estimation of the infection rate and illustrate it with reference to the Abakaliki data.

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00497.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryMinimum distance statistics for testing inequality restrictions on the mean vector of a multivariate normal population are considered and are shown to be equivalent to certain induced (or intersection) test statistics. Tests based on these statistics are shown to be admissible.

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00498.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryGiven observations on an m × n lattice, approximate maximum likelihood estimates are derived for a family of models including direct covariance, spatial moving average, conditional autoregressive and simultaneous autoregressive models. The approach involves expressing the (approximate) covariance matrix of the observed variables in terms of a linear combination of neighbour relationship matrices, raised to a power. The structure is such that the eigenvectors of the covariance matrix are independent of the parameters of interest. This result leads to a simple Fisher scoring type algorithm for estimating the parameters. The ideas are illustrated by fitting models to some remotely sensed data

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00499.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryControl charts typically used to monitor process centrality and dispersion either assume normally distributed output or appeal to the viability of the central limit theorem. This appeal to the central limit theorem is frequently made on behalf of samples consisting of 10 or fewer items. Control charts for centrality and dispersion are presented for processes with inverse Gaussian distributed output.

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00500.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryThis paper presents further results on a class of designs called equineighboured designs, ED. These designs are intended for field and related experiments, especially whenever there is evidence that observations in the same block are correlated.An ED has the property that every unordered pair of treatments occurs as nearest neighbours equally frequently at each level. Ipinyomi (1986) has defined and shown that ED are balanced designs when neighbouring observations are correlated. He has also presented ED as a continuation of the development of optimal block designs.An ED would often require many times the number of experimental materials needed for the construction of an ordinary balanced incomplete block, BIB, design for the same number of treatments and block sizes. Thus for a relatively large number of treatments and block sizes the required minimum number of blocks may be excessively large for practical use of ED.In this paper we shall define and examine partially equineighboured designs with n concurrences, PED (n), as alternatives where ED are practically unachievable. Particular attention will be given to designs with smaller numbers of blocks and for which only as little balance as possible may be lost.

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00501.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

summaryUsing some uniform asymptotic expansions for parabolic cylinder functions recently developed by Olver (1959), various integrals associated with the sequentialt‐andt2‐tests are evaluated asymptotically in terms of the sample size. Then the continuation region inequalities for these tests are inverted and expressed in terms of well known test criteria. It should be pointed out that the inversion of the continuation regions in terms of the well known statistics yields forms for the sequential tests that are more easily applicable by the practitioner than the forms yielded by the method of Rushton. Furthermore, using these inequalities and the asymptotic normality of the test criteria, finite sure termination of sequentialt‐andt2‐test procedures readily follow. Based on simulation studies, power comparisons of the two approximations are al

ISSN:0004-9581    

DOI:10.1111/j.1467-842X.1989.tb00502.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY