...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Forest Planning >Characteristics of Parameters in Power Equation Representing Sunny Crown Profile of Hinoki Cypress Tree
【24h】

Characteristics of Parameters in Power Equation Representing Sunny Crown Profile of Hinoki Cypress Tree

机译：代表H木柏树晴天冠轮廓的功率方程参数的特征

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Characteristics of parameters in power equation (r = az~b where r is the crown radius (m) at a given distance z (m) from the tree apex, and a and b are parameters) for representing the sunny crown profile were examined for Hinoki cypress (Chamaecyparis obtusa ENDL.). Three hypothetical models were constructed; Model 1: the values of a and b are unique for each tree, Model 2: the value of b is common to all trees, Model 3: the values of a and b are common to all trees. The three models were compared using AKAIKE'S information criterion (AIC) and root mean squared error (RMSE). Data were obtained from 112 sample trees selected in six pure stands of even-aged Hinoki cypress. Model 3 was inferior to the other two models in terms of AIC and RMSE. Model 2was superior to Model 1 in terms of AIC. Although Model 2 gave a larger value of RMSE than that of Model 1, the difference was only 0.006m. When the profile of the sunny crown of a Hinoki cypress tree is represented by the power equation, we can assumethat parameter b is invariant between trees and that parameter a varies from tree-to-tree.
机译：检验了幂方程中参数的特性（r = az〜b，其中r是距树顶点的给定距离z（m）处的树冠半径（m），a和b是参数），用于表示晴天树冠轮廓扁柏（Chamaecyparis obtusa ENDL。）。构建了三个假设模型;模型1：a和b的值对于每棵树都是唯一的，模型2：b的值对于所有树都是公共的，模型3：a和b的值对于所有树都是公共的。使用AKAIKE的信息准则（AIC）和均方根误差（RMSE）比较了这三个模型。数据来自在均匀年龄的扁柏的六个纯林中选择的112棵样本树。在AIC和RMSE方面，模型3低于其他两个模型。在AIC方面，模型2优于模型1。尽管模型2给出的RMSE值比模型1大，但差异仅为0.006m。当用功率方程表示H木柏树的树冠的轮廓时，我们可以假设参数b在树之间是不变的，并且参数a随树而变化。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号