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71.
Differences between plant varieties are based on phenotypic observations, which are both space and time consuming. Moreover, the phenotypic data result from the combined effects of genotype and environment. On the contrary, molecular data are easier to obtain and give a direct access to the genotype. In order to save experimental trials and to concentrate efforts on the relevant comparisons between varieties, the relationship between phenotypic and genetic distances is studied. It appears that the classical genetic distances based on molecular data are not appropriate for predicting phenotypic distances. In the linear model framework, we define a new pseudo genetic distance, which is a prediction of the phenotypic one. The distribution of this distance given the pseudo genetic distance is established. Statistical properties of the predicted distance are derived when the parameters of the model are either given or estimated. We finally apply these results to distinguishing between 144 maize lines. This case study is very satisfactory because the use of anonymous molecular markers (RFLP) leads to saving 29% of the trials with an acceptable error risk. These results need to be confirmed on other varieties and species and would certainly be improved by using genes coding for phenotypic traits. 相似文献
72.
G = F
k
(k > 1); G = 1 − (1−F)
k
(k < 1); G = F
k
(k < 1); and G = 1 − (1−F)
k
(k > 1), where F and G are two continuous cumulative distribution functions. If an optimal precedence test (one with the maximal power) is determined
for one of these four classes, the optimal tests for the other classes of alternatives can be derived. Application of this
is given using the results of Lin and Sukhatme (1992) who derived the best precedence test for testing the null hypothesis
that the lifetimes of two types of items on test have the same distibution. The test has maximum power for fixed κ in the
class of alternatives G = 1 − (1−F)
k
, with k < 1. Best precedence tests for the other three classes of Lehmann-type alternatives are derived using their results. Finally,
a comparison of precedence tests with Wilcoxon's two-sample test is presented.
Received: February 22, 1999; revised version: June 7, 2000 相似文献
73.
We define a notion of de-initializing Markov chains. We prove that to analyse convergence of Markov chains to stationarity, it suffices to analyse convergence of a de-initializing chain. Applications are given to Markov chain Monte Carlo algorithms and to convergence diagnostics. 相似文献
74.
The non-parametric maximum likelihood estimators (MLEs) are derived for survival functions associated with individual risks or system components in a reliability framework. Lifetimes are observed for systems that contain one or more of those components. Analogous to a competing risks model, the system is assumed to fail upon the first instance of any component failure; i.e. the system is configured in series. For any given risk or component type, the asymptotic distribution is shown to depend explicitly on the unknown survival function of the other risks, as well as the censoring distribution. Survival functions with increasing failure rate are investigated as a special case. The order restricted MLE is shown to be consistent under mild assumptions of the underlying component lifetime distributions. 相似文献
75.
C. E. Stein S. Bennett S. Crook & F. Maddison 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2001,164(1):23-27
In 1997 intense media coverage raised public concerns about germ warfare simulation experiments conducted by the Ministry of Defence during the 1960s, which included the release of bacteria over Dorset. Families in East Lulworth, Dorset, have linked this with allegedly high rates of miscarriages, still-births, congenital malformations, learning and other neurodevelopmental disabilities in their village. The response of the Dorset Health Authority (DHA) included the examination of background information from the Ministry of Defence, national data on congenital malformations in Dorset, health information collected by campaigners and a systematic health survey conducted by the DHA among former and current residents of East Lulworth. The investigation did not confirm the presence of a cluster. It is debatable whether the DHA should have proceeded with their survey when none of the other more immediately available results indicated the presence of a cluster. 相似文献
76.
77.
In a searching analysis of the fiducial argument Hacking (1965) proposed the Principle of Irrelevance as a condition under which the argument is valid. His statement of the Principle was essentially non-mathematical and this paper presents a mathematical development of the Principle. The relationship with likelihood inference is explored and some of the proposed counter-examples to fiducial theory are considered. It is shown that even with the Principle of Irrelevance examples of non-uniqueness of fiducial distributions exist. 相似文献
78.
For two-level factorials, we consider designs in N=2 (mod 4) runs as obtained by adding two runs, with a certain coincidence pattern, to an orthogonal array of strength two. These designs are known to be optimal main effect plans in a very broad sense in the absence of interactions. Among them, we explore the ones having minimum aberration, with a view to ensuring maximum model robustness even when interactions are possibly present. This is done by sequentially minimizing a measure of the bias caused by interactions of successively higher orders. 相似文献
79.
Eleanor S. Bagley 《The American statistician》2013,67(4):11-14
For much of 1970 and during the early part of 1971 some forty members of the American Statistical Association, working as seven task force groups under the guidance of a special Steering Committee, gave much time and thought to an examination of the objectives and activities of ASA. Their purpose was to try to determine what those objectives should be and how best to accomplish them. After careful review and study by the Board of ASA, the task force and steering committee findings and recommendations were adopted, modified or supplemented and issued as an integrated Board report under the title of A Study of Future Goals of ASA. 相似文献
80.