The method of Zeng et al. (1991) employed diameter growth to estimate the transition probability of the matrix model in uneven-aged forest stands. In this paper the Weibull distribution for even-aged forest stands ins...The method of Zeng et al. (1991) employed diameter growth to estimate the transition probability of the matrix model in uneven-aged forest stands. In this paper the Weibull distribution for even-aged forest stands instead of uniform distribution chosen by Zeng is used. By comparing the results of the improved method with those of the original method of Zeng, it turns out that the improved method of Zeng given in this paper is more efficient.展开更多
The even degree of chicken population could be estimated by the coefficient of variation or the percentage of the chicken whose body weights were not higher and lower than average body weight by 15% in the sampling po...The even degree of chicken population could be estimated by the coefficient of variation or the percentage of the chicken whose body weights were not higher and lower than average body weight by 15% in the sampling population.In fact,the two indexes were relative to each other.On the basis of analyzing the relationship between the two expectations,the expectations which had been worked out independently were corrected in this paper.展开更多
The even degree of animal population is generlay measured by the coefficient of variation of major economic characters.Facing the coefficient of variation,a statistic with complex properties,we achieved indirectly the...The even degree of animal population is generlay measured by the coefficient of variation of major economic characters.Facing the coefficient of variation,a statistic with complex properties,we achieved indirectly the determination of confidence interval for even degree of an animal population by analysing the reciprocal of the statistic.The sample size which is suitable to the determination of the even degree of an animal population was probed into within the extent of permissive estimation error.展开更多
基金This paper was supported by the National Natural Science Foundation of China
文摘The method of Zeng et al. (1991) employed diameter growth to estimate the transition probability of the matrix model in uneven-aged forest stands. In this paper the Weibull distribution for even-aged forest stands instead of uniform distribution chosen by Zeng is used. By comparing the results of the improved method with those of the original method of Zeng, it turns out that the improved method of Zeng given in this paper is more efficient.
基金Financed by the Heilongjiang province natural science fund
文摘The even degree of chicken population could be estimated by the coefficient of variation or the percentage of the chicken whose body weights were not higher and lower than average body weight by 15% in the sampling population.In fact,the two indexes were relative to each other.On the basis of analyzing the relationship between the two expectations,the expectations which had been worked out independently were corrected in this paper.
文摘The even degree of animal population is generlay measured by the coefficient of variation of major economic characters.Facing the coefficient of variation,a statistic with complex properties,we achieved indirectly the determination of confidence interval for even degree of an animal population by analysing the reciprocal of the statistic.The sample size which is suitable to the determination of the even degree of an animal population was probed into within the extent of permissive estimation error.
