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一种动物种群规模估计量
A method of estimating animal populations which is popular among zoologists is to take the total of the ages of animals that die during a given year as an estimator of population size. In this note the bias and variance of the estimator are investigated for a stationary model, and for one based on a branching process. A numerical illustration is given.
一种动物种群规模估计量
A method of estimating animal populations which is popular among zoologists is to take the total of the ages of animals that die during a given year as an estimator of population size. In this note the bias and variance of the estimator are investigated for a stationary model, and for one based on a branching process. A numerical illustration is given.
角计数法
This paper deals with Bitterlich's angle-count method of estimating the basal area proportion in forestry. In § 1 the sampling distribution of the estimator is derived on the assumption that the trees are distributed randomly, and in §2 the angle-count estimator is compared with the more conventional one based on sample plots. In the next section the results are illustrated in a more concrete form by choosing a specific distribution for the radii of the trees. The effect of…
Neyman A型分布的二元推广
Three generalizations of the Neyman Type A distribution (Neyman, 1939) to the bivariate case are introduced, each of which is such that each of its marginal distributions is univariate Neyman A. The models from which they arise seem appropriate in certain ecological situations. Method of moments estimators of the parameters are derived, and an example is given of an attempt to fit the three distributions to ecological data. The problems of maximum-likelihood estimation and…