At any knots, the nearly arc length are precise for the resulting nearly arc length parametric curve, and it has the unit tangent same as that of the real arc length parametric curve.
所作近似弧长参数化曲线在插值节点处，近似弧长是精确的，并且具有与精确弧长参数曲线同方向的单位切矢。
2
The locus of space tangent point and the arc segment of deck at side are obtained based on the above conditions.
在此基础上，求出首圆弧空间切点线和甲板边线的修正段。
3
Compared with modified arctangent function model, it is more reasonable for predicting the slope of the characteristic of the core at deep saturation.