基于三次指数平滑法的黄山风景区旅游营业总收入预测分析

指数平滑法就是将历史统计数据消除统计数据的起伏波动状况,使其规则化,以便把握事物发展的方向和趋势的方法,根据近几年黄山风景区旅游营业总收入数据分析,利用三次指数平滑法预测2010年和2011年黄山风景区旅游营业总收入将达到12.3906亿元和13.2809亿元.     

数控加工编程及操作课程的“圆弧插补指令”教学探讨

《数控加工编程及操作》是高等职业教育中数控技术专业的核心专业课之一,该课程实践性较强。基本编程指令的教和学不容忽视,其中圆弧插值指令G02/G03的掌握难度更大。文章结合自己的教学经验,总结了圆弧插补指令G02/G03指令的学习步骤,为其他指令的学习提供了借鉴。     

一种用于山区土壤重金属评估的集成RBF空间插值算法(英文)

提出了一种在山区能够准确、稳定地预测未采样点土壤重金属浓度的集成径向基函数神经网络空间插值方法(IRBFANNs).该方法集成径向基函数神经网络和神经网络集成技术的优点.为了研究所提IRBFANNs方法的性能,进行了3组不同采样密度条件下的实验.通过M n元素插值的均方根误差和分布估计图对IRBFANNs和其他6个插值方法进行了比较.实验结果表明:IRBFANNs方法在精确性和稳定性方面优于其他参评方法,且在采样密度稀疏条件下该方法能够提供细节较丰富的分布估计图.     

圆锥曲线的有理三次Bezier表示

给出圆锥曲线上的两个控制点,利用有理曲线升阶方法,求出有理三次B6zier曲线的另外两个控制顶点以及权因子γ的值,从而达到用有理三次B6zier曲线对已给定的圆锥曲线的精确表示,如双曲线弧、抛物线弧和椭圆弧的表示。并给出了数值实例。     

用非规则节点解偏微分方程的局部微分求积法

In the conventional differential quadrature (DQ) method the functional values along a mesh line are used toapproximate derivatives and its application is limited to regular regions. In this paper, a local differential quadrature (LDQ)method was developed by using irregular distributed nodes, where any spatial derivative at a nodal point is approximatedby a linear weighted sum of the functional values of nodes in the local physical domain. The weighting coefficients in thenew approach are determined by the quadrature rule with the aid of nodal interpolation. Since the proposed method directlyapproximates the derivative, it can be consistently well applied to linear and nonlinear problems and the mesh-free feature isstill kept. Numerical examples are provided to validate the LDQ method.     

Paths of algebraic hyperbolic curves

Cubic algebraic hyperbolic （AH） Bezier curves and AH spline curves are defined with a positive parameter a in the space spanned by {1, t, sinht, cosht}. Modifying the value of a yields a family ofAH Bezier or spline curves with the family parameter α. For a fixed point on the original curve, it will move on a defined curve called ＂path of AH curve＂ （AH Bezier and AH spline curves） when a changes. We describe the geometric effects of the paths and give a method to specify a curve passing through a given point.     

Valence band offsets of the strained and longitudinally relaxed diamond/c-BN superlattices

The valence band offsets of the strained and longitudinally relaxed diamond/cubic boron-nitride (c-BN) (110) superlattice are investigated by the plane wave density functional theory approach and using the on-site core electron as a reference energy level. For the strained diamond/c-BN superlattice, the valence band offset of around 1.50 eV is in good agreement with those using all the electrons methods. As for the longitudinally relaxed superlattice, the valence band offset of around 1.28 eV is smaller tha...     

数值分析课程中三次样条插值的教学探讨

三次样条插值由于良好的光滑性而在工程中应用非常广泛,同时又由于它的定义复杂、插值函数难于求解,使得三次样条插值成为教学中的重点和难点。为了使学生更加容易理解三次样条插值的概念,并熟练运用三次样条插值解决实际问题,在教学中首先通过实例激发学生思考,引起学生的学习兴趣;然后引入三次样条插值的概念,并从理论上给出三次样条插值的求解方法;最后再应用Matlab实现三次样条插值。     

基于联合双边滤波器上采样的纹理图像修复合成算法

基于双边滤波器上采样算法提出了一种修复图像纹理的合成方法,以计算的样本纹理作为引导纹理,对低分辨率的待修复纹理图像区域的纹理进行插值运算,实现高分辨率的修复。仿真结果表明,该法提高了待修复纹理图像区域的分辨率。     

Newton插值公式的推广

把计算方法中差商的概念改进为多级差商，得出了多级Newton插值公式的推广，使过去熟知的Newton前差公式、Newton后差公式和导数的Taylor公式等内容得到了统一和推广。