检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
出 处:《西北农林科技大学学报(自然科学版)》2015年第11期82-90,共9页Journal of Northwest A&F University(Natural Science Edition)
基 金:国家林业局重点项目(2012-07);林业公益性行业科研专项(200904003-1);林业科技成果国家级推广项目([2014]26)
摘 要:【目的】比较3种标准树高曲线建立方法的优劣,为选择适宜的标准树高曲线建立方法提供依据。【方法】以福建省将乐县国有林场29块杉木人工林实测数据为依据,采用传统非线性模型、BP神经网络模型、非线性混合模型分别建立杉木标准树高曲线模型,以决定系数R2、均方根误差RMSE以及平均绝对残差|珚E|作为模型评价和检验指标,对比分析三者的拟合效果。【结果】从拟合精度来看,非线性混合模型、BP神经网络模型、传统模型的决定系数分别为0.916 1,0.904 8和0.889 7,RMSE分别为1.652 9,1.761 2和1.895 4,|珚E|分别为1.205 9,1.291 7和1.400 1;从预测精度来看,三者的决定系数分别为0.941 5,0.935 2和0.918 3,RMSE分别为1.361 8,1.432 2和1.609 0,|珚E|分别为0.989 8,1.030 5和1.142 8。【结论】3种方法均能较好地模拟杉木树高的生长,BP神经网络模型与非线性混合模型的拟合精度和预测能力均较传统的非线性模型好,但非线性混合模型略优于BP神经网络模型。【Objective】The advantages of three methods for constructing generalized height-diameter curve were compared to provide basis for choosing optimal method.【Method】The data from 29 Cunninghamia lanceolata plots located in national forest farm of Jiangle in FuJian were used to develop the generalized height-diameter curve for C.lanceolata.The curve was built by traditional nonlinear model,BP neural network model and nonlinear mixed model,respectively.The simulation effects of three models were compared using coefficient of determination(R^2),root mean square error(RMSE),and absolute mean error(E珚).【Result】Based on fitting accuracy,the coefficients of determination of nonlinear mixed model,BP neural network model and traditional nonlinear model were 0.916 1,0.904 8,and 0.889 7,the root mean square errors were 1.652 9,1.761 2,and 1.895 4,and the absolute mean errors were 1.205 9,1.291 7,and1.400 1,respectively.Based on prediction precise,the coefficients of determination were 0.941 5,0.935 2,and 0.918 3,and the root mean square errors were 1.361 8,1.432 2,and 1.609 0,and the absolute mean errors were 0.989 8,1.030 5,and 1.142 8,respectively.【Conclusion】All three methods could simulate height growth of C.lanceolata well.The simulation and prediction accuracies of BP neural network model and nonlinear mixed model were better than that of traditional nonlinear model.Nonlinear mixed model was slightlybetter than BP neural network model.
关 键 词:杉木 标准树高曲线 传统非线性模型 BP神经网络 非线性混合模型
分 类 号:S791.27[农业科学—林木遗传育种] S758.5[农业科学—林学]
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.26