摘要:

AbstractIn the present paper some basic aspects of the WILCOXON‐MANN‐WHITNEY‐test under various assumptions concerning the underlying distributions are studied. Starting with a formal analogy to Student'st‐test its specific sensibility is worked out and the connexion to the problem of testing differences in location is discussed in detail as well as to the model with ordered alternatives. Further a counter example is given showing that the common verbal formulation the WILCOXON‐MANN‐WHITNEY‐test being a test on ‘differences in distribution’ in general is misleading. As an example of an extended application of the WILCOXON‐MANN‐WHITNEY‐statistic the test of POTT‐HOFF(1963) on differences in medians of symmetric distributions is treated together with a discussion on suitable variance estimators to guarantee appropriat

ISSN:0323-3847    

DOI:10.1002/bimj.4710240102

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractIf the variables in MANOVA problem can be arranged according to the order of their importance, then J. ROY'S(1958) step‐down procedure may be more appropriate than the conventional invariant inference techniques. However, it may often be possible only to identify subsets such that variables within subsets are equally important and subsets are of unequal importance. In experimental situations, it is common to have a set of variables of primary interest and another of “addon” variables. The step‐down reasoning is extended to such cases and a set of simultaneous confidence bounds based upon the procedure which uses the largest root criterion at each stage are derived. The confidence bounds are on all linear functions of means only that do not involve nuisance parameters, and are therefore suitable for studying the configuration of means. This method yields shorter intervals for contrasts among the means of the variables of primary interest compared with the conventional intervals based upon the largest root. The method is illustrated using BARNARD'Sdata (1935) on skull cha

ISSN:0323-3847    

DOI:10.1002/bimj.4710240103

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractBased on the principles introduced by TUKEYand FRASER, a method is proposed to construct non‐parametric multivariate tolerance regions of irregular multiplanar shape. Contrary to the regions of corresponding shape as constructed by Tukey and Fraser, the tolerance regions constructed according to the proposed method can be shown to be invariant to linear scale transformations. In medical applications, where the concept of multivariate tolerance regions can be used to define “normal” regions forp≦ 2 variables with measuring units generally differing from each other, the quality of scale‐independency of the regions is essential. With reference to the method proposed, sample size determination and some important aspects of the use of multivariate tolerance regions are

ISSN:0323-3847    

DOI:10.1002/bimj.4710240104

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractSpatial point patterns which possess a natural origin are considered. Two ways of estimating the marginal radial and angular probability density functions associated with the stochastic process underlying such a pattern are presented. These methods are based on one and two‐dimensional kernel functions respectively. The angular density estimate can be used to detect angular trend and to test for angular uniformity within a particular sector about the origin. The two methods of estimation produce essentially the same results. That based on the one‐dimensional kernel is recommended because it is computationally simp

ISSN:0323-3847    

DOI:10.1002/bimj.4710240105

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe usual definitions of sensitivity, specificity and predictive value of a diagnostic testTrefer only to the situation of the presence or absence of disease. There is then question of the appropriate extensions of these definitions in cases where there are more than two diagnostic categories, especially with ordered or graded responses. This paper deals with some aspects of this problem. An example with the data of BERGESONand STEINFELD(1974) on gradings of fever in children by palpation is analyzed, using the methods discussed in this paper.

ISSN:0323-3847    

DOI:10.1002/bimj.4710240106

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractTo study the behaviour of a living cell exposed to radiations we investigate a stochastic model, employing for its analysis the theory of semi‐Markov and Markov renewal processes. Four states of the cell namely, normal state, damaged state 1, damaged state 2 and altered state are defined and various characteristics of interest pertaining to the cell behaviour are studie

ISSN:0323-3847    

DOI:10.1002/bimj.4710240107

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractA biological assay that quantifies hazardous response in living matter to an electromagnetic stimulus, is evolved. Considering the various susceptible aspects of physio‐anatomical systems constituting a living subject, a dominance criterion to determine an optimum all‐or‐none response limit of exposure to electromagnetic pollutions is established. Based on the statistics of proneness and susceptibility of discrete physio‐anatomical parts of living systems (biotic components) to polluting radiations (abiotic environment), the stochastic nature of damage involved is considered to formulate a quantal index which specifies a “safe” intensity‐level of electromagnetic radiation to which living systems can be exposed without encountering any deleterious effects. The locations of vulnerable parts which are affected by radiation are identified through random mosaic modeling of a test subject. Using this model, a susceptance priority sequence of biotic components is constructed. This sequence is then terminated at a point of weightage proportional to the diversity of victim population. The biotic species falling within this limit of truncation are subsequently studied to assay the tolerance (optimum lethal dose) of the test subject to the radiation in question. The possibility of simulating the entire ecological system under consideration by means of a microprocessor

ISSN:0323-3847    

DOI:10.1002/bimj.4710240108

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractIn this paper we analyse the migration process in connection with the birth and death process. We assume that the populations are distributed spatially and are subject to birth, death and migration to or from neighbouring populations. Furthermore, we distinguish between populations with infinite and finite number of colonies. By this way we calculate the cumulant of first order.First this problem was studied by BAILEYand ADKEfor time‐dependent rates. Similarly PURIhas specialized the problem for right migration (vij= 0 fori≢j). Finally RENSHAWhad the same result with other procedu

ISSN:0323-3847    

DOI:10.1002/bimj.4710240109

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractAn approximate formula is derived for determination of the sample sizes needed to detect a difference between two binomial probabilities.

ISSN:0323-3847    

DOI:10.1002/bimj.4710240110

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY

摘要:

AbstractThe functional form of the class of Bivariate Modified Power Series Distributions is considered. The probabilities are functions of two unknown parameters ϑ1and ϑ2.The necessary and sufficient conditions for the existence of a minimum variance unbiased estimator for a parametric function of ϑ1and ϑ2are gi

ISSN:0323-3847    

DOI:10.1002/bimj.4710240111

出版商:WILEY‐VCH Verlag    

年代:1982

数据来源: WILEY