林分直径分布的Weibull参数估计系统研制

Compilation of stand diameter distribution of Weibull parameters estimation system

基于Weibull分布3参数的人工神经网络估计模型,用MATLAB的GUI界面编制了Weibull参数估计系统（WPES）。以3个年龄段（14、22和30 a）的贵州马尾松人工林直径分布数据为验证材料,用最大似然估计（MLE）为对照,对WPES的准确性和适应性进行了精度检验和χ2检验分析。2种方法对3个年龄段直径分布的拟合精度分别为：84%、85%、85%和78%、64%、67%;χ2种检验统计量分别为7.17、8.73、2.40和52.62、45.31、7.96。分析结果表明,WPES的拟合精度较高,比MLE高5%-20%;WPES对不同时间和空间的适应性较强,其变动幅度是MLE的1/10。

Based on the artificial neural network of Weibull distribution three parameters estimation model, Weibull parameters estimation model is compiled with MATLAB GUI interface system （WPES）. The diameter distribution data of three ages of pinus massoniana 14, 22, 30（a） plantation in Guizhou, were used as materials to verify the accuracy and adaptability of WPES with the maximum likelihood estimation （MLE） as control. The fitting precision of diameter distribution for the three ages based on the two methods were respectively, 84% , 85% , 85% and 78% , 64% , 67% ; Chi-square test statistics were 7.17, 8.73, 2.40 and 52.62, 45.31, and 7.96, respectively. The analysis results show that the WPES fitting accuracy is higher, 5%～ 20% higher than that of the MLE. WPES had good adaptability to different time and space, and the variation range was 10 times smaller than that of the MLE.