二维任意形状寄生电阻电容的边界元计算

由于集成电路技术高速发展,精确提取任意形状寄生电阻电容变得十分重要,本文以直接边界元素法为基础,利用圆弧样条插值近似任意曲线边界,使插值曲线具有整体一阶连续性,并克服了大挠度与多值的困扰。在直线边界使用线性连续元,在曲线边界使用二次连续无。对两邻国为直线的角点,我们曾提出处理角点处存在多重法的导数的一种方法。这里,它被推广到角点邻边含曲线段的情形。数值结果表明模拟器是可行的。     

血液粘度仪旋转锥体角速度误差分析与补偿

剪切池内旋转锥体的角速度是新型锥板式血液粘度仪的主要信息源,其精度取决于光电传感器和齿形盘.分析了光电传感器的点光源特性和齿形盘的周期性摆动及其加工精度导致的角度误差.针对锥体角速度的单调递减特性、角度误差在单转内的随机性及整个测量过程中呈周期性,采用有理三次样条插值算法对角速度误差进行补偿.实验结果表明:该方法可提高...     

一种二次样条保单调Hermite插值方法

提出一种保单调的二次样条Hermite插值方法。该方法在研究总结其他二次样条插值方法的基础上,通过设定适当的结点斜率保证了插值曲线的单调性,并且给出了算法的严格证明;该算法在一个给定的点列上进行了验证,验证结果表明该算法可以得出连续、平滑的插值曲线,具备较为优秀的性能。     

基于三次样条插值的采样数据光滑曲线形成法

在计算机机辅助测试（CAT）中,所测得的数据一般为一系列的离散系统样数据,怎样将它恢复为不失真的连续光滑曲曲线并打全出呢？本文提出了三次样条插值函数的形成法及其局限性,并对三次样条插值提取出了改进方法,使测得的一系列离散点能形成光滑的曲线。     

Construction and properties of spline dyadic wavelet filters

This paper focuses on the construction and properties of spline dyadic wavelet that equals its reconstruction wavelet. A general construction method of finite spline dyadic low-pass and high-pass filters is given. It proves that finite spline dyadic low-pass filters are symmetric about 0 or 1/2, but there are no finite spline high-pass filters possessing symmetry with respect to 0 or 1/2. It further shows that there exist infinite spline high-pass filters possessing symmetry with respect to 0 or 1/2, which can be constructed. Their energy is concentrated and so finite symmetric spline dyadic wavelet filter that equals its reconstruction filter can be obtained approximately. Construction examples for quadratic and cubic spline dyadic wavelet filters are given.     

Sextic spline solution of variable coefficient fourth-order parabolic equations

We report new three-level implicit methods of O(k ²+h ⁴) and O(k ⁴+h ⁴) for the numerical solution of fourth-order non-homogeneous parabolic partial differential equation with variable coefficients. We use sextic spline in space and finite difference in time directions. Sextic spline function relations are derived by using off-step points. The linear stability of the presented method is investigated. We solve test problems numerically to validate the derived methods. Numerical comparison with other existence methods shows the superiority of our presented scheme.     

Study of Quintic Spline Interpolation and Generated Velocity Profile for High Speed Machining

Modern high speed machining (HSM) machine tools often operates at high speed and high feedrate with high ac- celerations,in order to deliver the rapid feed motion.This paper presents an interpolation algorithm to generate continuous quintic spline toolpaths,with a constant travel increment at each step,while the smoother accelerations and jerks of two-order curve are obtained.Then an approach for reducing the feedrate fluctuation in high speed spline interpolation is presented.The presented ap- proach has been validated to quickly,reliably and effective with the simulation.     

An investigation into design of fair surfaces over irregular domains using data-dependent triangulation

Design of fair surfaces over irregular domains is a fundamental problem in computer-aided geometric design (CAGD), and has applications in engineering sciences (in aircraft, automobile, ship science etc.). In the design of fair surfaces over irregular domains defined over scattered data, it was widely accepted till recently that the classical Delaunay triangulation be used because of its global optimum property. However, in recent times it has been shown that for continuous piecewise linear surfaces, improvements in the quality of fit can be achieved if the triangulation pattern is made dependent upon some topological or geometric property of the data set or is simply data dependent. The fair surface is desired because it ensures smooth and continuous surface planar cuts, and these in turn ensure smooth and easy production of the surface in CAD/CAM, and favourable resistance properties. In this paper, we discuss a method for construction of C¹ piecewise polynomial parametric fair surfaces which interpolate prescribed ℜ³ scattered data using spaces of parametric splines defined on H³ triangulation. We show that our method is more specific to the cases when the projection on a 2-D plane may consist of triangles of zero area, numerically stable and robust, and computationally inexpensive and fast. Numerical examples dealing with surfaces approximated on plates, and on ships have been presented.     

基于测量数据优化修匀的特性曲线样条插值方法

针对传感器特性曲线拟合存在的一些问题,提出了测量数据优化修匀思想以有效消除测量数据的随机误差.应用数值处理软件Matlab结合实验数据研究了基于不同修匀方案的特性曲线的三次样条插值表示并提供了可视化的结果.经过对比不难发现,依据优化修匀数据的三次样条插值误差明显减小,可应用于任意类型传感器或其它仪器仪表的特性曲线的描述与分析.