Based on the fourth - order difference formula of the second derivative term , a fourth - order finite difference method is developed for solving two - points boundary value problem 摘要从中心差分公式出发,利用二阶微分的四阶差分公式,对两点边值问题得到了一种四阶精度的差分格式。
Thirdly , the effects on the cv rational interpolating splines from the perturbation of the two boundary conditions are analyzed . from this the error bounds of first and second derivatives of cv rational interpolating spline are given 然后,分析了两类端点条件的扰动对cv有理插值样条函数的影响,给出了它们在非均匀节点处的一阶和二阶导数值的误差界
Since motion simulator focuses on reproduction of motion , it makes great sense to calculate its first and second derivative of kinematic parameters for improvement and evaluation of performance of motion simulator 由于运动模拟器注重于动感的再现,因此, stewart平台的一阶、二阶运动学参数的计算对提高运动模拟器的质量以及评价运动模拟器的性能具有重要的意义。
By the reason of characteristic on statistics of images , we gave a face searching and locating algorithm based on the second derivatives operator . we obtain the position of face by calculating the change of projection curve using the second operator 该方法计算人脸在两个投影方向上的统计特征,使用二阶微商算子估计投影曲线斜率的变化,进而找出人脸的外接矩形,判断头部在图象中的位置。
In calculus, the second derivative of a function ? is the derivative of the derivative of ?. Roughly speaking, the second derivative measures how the rate of change of a quantity is itself changing; for example, the second derivative of the position of a vehicle with respect to time is the instantaneous acceleration of the vehicle, or the rate at which the velocity of the vehicle is changing.