论文部分内容阅读
该文探讨了不用编制削度表直接建立高精度立木干曲线的方法．当采用干曲线是３次多项式时，通常根据１０分法测定树干各部位直径，用最小二乘法求出该方程式的参数．从数学角度，只要知道树干任意３个部位的直径，就可以用最小二乘法或联立方程式求解干曲线参数．本文以樟子松为例，探讨用树干哪３个部位直径拟合的干曲线最接近实际干曲线，为建立立木干曲线提供有效方法．利用９个部位半径（方法Ⅰ）和利用其中３个部位半径（方法Ⅱ，２８种组合）分别拟合干曲线，结果表明方法Ⅱ的６种半径组合的精度良好，其中的３种组合，（ｒ１．３，ｒ０．３，ｒ０．７），（ｒ１．３，ｒ０．４，ｒ０．７）和（ｒ１．３，ｒ０．４，ｒ０．８）是拟合现实干曲线的有效方法．
This article explores the method of establishing a high-precision stand-up curve without the need to program a tapping table. When the dry curve is a polynomial of the third degree, the diameter of each part of the trunk is usually determined by the 10-point method, and the parameters of the equation are found by the least square method. From a mathematical point of view, the dry curve parameters can be solved using the least-squares method or the simultaneous equations by knowing the diameter of any three parts of the tree trunk. This paper takes Pinus sylvestris var.Mongolica as an example to explore the dry curve fitted by the diameter of the three parts of trunk which is closest to the actual dry curve and provides an effective method for establishing the trunk curve. The results showed that the accuracy of six methods of method Ⅱ was good, and the three kinds of combinations (((Ⅰ) and (Ⅲ) r1.3, r0.3, r0.7), (r1.3, r0.4, r0.7) and (r1.3, r0.4, r0.8) are effective methods for fitting a realistic dry curve.