三次多项式样条解一类四阶边值问题

应用三次多项式样条函数解一组四阶单侧、障碍、接触边值问题,取半结点为网格点,并增加了边界方程,应用方法解文献中的数值例子,说明了方法的高效性,数值结果也显示了方法的优越性.     

二元三次一阶光滑的分片多项式样条函数

一元样条大致从以下三个方向上发展起来的:一元截断多项式样条;一元B-样条;一元分片多项式样条。二元样条的研究已取得了不少进展,文[2]可视为一元截断多项式样条向二元截断多项式样条推广的奠基性的工作,文[3]又讨论了二元B样条的构造方面的进展,但一元分片多项式样条的构造方法如何推广到二元样条上来,几乎没有见到什么工作。我们曾在文[4]中作过一点努力,但那是讨论二元二     

用低次叠样条函数逼近导函数

本文讨论了用低次样条函数的叠样条来逼近导函数的问题.给出了叠样条的构造、误差分析及余项的逐项渐进展开式.     

基于线性规划和多项式样条函数的利率期限结构模型

针对线形规划利率期限结构模型只能得到离散贴现率,提出利用多项式插值方法拟合出连续光滑的利率期限结构.并依据样本内外国债信息把它与多项式样条函数模型进行了实证比较,前者的价格相对误差分别为0.45%和1.51%,后者分别为4.18%和4.5%.结果表明线性规划利率期限结构模型与多项式插值相结合的方法在拟合我国利率期限结构方面具有一定优势.     

一类基于l1模的最佳二次样条插值

本文讨论了二次样条插值的定解条件,在l_1模意义下给出了一类最佳二次样条插值的概念,以及寻找最佳二次样条插值的定解条件的方法.最后讨论了误差估计问题,并给出了实际算例.     

非等距划分下样条函数的渐近展开

本文采用传递插值的方法对非等距划分情况下亏度为(n-1)的(2n-1)次缺插值样条函数余项进行了渐近展开,得到了较普遍的结果。这种方法对非等距情况下的渐近展开具有普遍的意义。     

一种四次有理插值样条及其逼近性质

1引言有理样条函数是多项式样条函数的一种自然推广,但由于有理样条空间的复杂性,所以有关它的研究成果不象多项式样条那样完美,许多问题还值得进一步的研究．近几十年来,有理插值样条,特别是有理三次有理插值样条,由于它们在曲线曲面设计中的应用,已有许多学者进行了深入研究,取得了一系列的成果(见[1]-[7])．但四次有理插值样条由于其构造所花费的计算量太大以及在使用上很不方便而让人们忽视了其重要的应用价值,因此很少有人研究他们．实际上,在某些情况下四次有理插值样条有其独特的应用效果,如文[8]建立的一种具有局部插值性质的分母为二次的四次有理样条,即一个剖分     

一类非线性常微分方程的非平凡解

本文论讨了三个问题：①二阶非线性微分方程的初值问题；②运用非线性算子证明了非平凡解的存在性和唯一性；③给出了一个非负非平凡解的估计式．     

具有代数体函数解的一类复常微分方程

本文应用Nevanlinna理论,研究了一类相当一般的复常微分方程的代数体函数解的存在性问题并得到若干新的结果。一、引言微分方程代数体函数解的存在性问题,首先由Malmquist所研究,吉田耕作首先应用Nevanlinna理论的方法重新证明和推广了Malmquist定理,其后,F. Gackstatter和I. Laine;何育赞与肖修治考虑了下述微分方程的相应问题:     

Parametric Cubic Spline Approach to the Solution of a System of Second-Order Boundary-Value Problems

We use parametric cubic spline functions to develop a numerical method for computing approximations to the solution of a system of second-order boundary-value problems associated with obstacle, unilateral, and contact problems. We show that the present method gives approximations which are better than those produced by other collocation, finite-difference, and spline methods. A numerical example is given to illustrate the applicability and efficiency of the new method.     

Quintic Spline Approach to the Solution of a Singularly-Perturbed Boundary-Value Problem

A fourth-order uniform mesh difference scheme using quintic splines for solving a singularly-perturbed boundary-value problem of the form

Parametric Quintic-Spline Approach to the Solution of a System of Fourth-Order Boundary-Value Problems

In this paper, we use parametric quintic splines to derive some consistency relations which are then used to develop a numerical method for computing the solution of a system of fourth-order boundary-value problems associated with obstacle, unilateral, and contact problems. It is known that a class of variational inequalities related to contact problems in elastostatics can be characterized by a sequence of variational inequations, which are solved using some numerical method. Numerical evidence is presented to show the applicability and superiority of the new method over other collocation, finite difference, and spline methods.     

微分方程模糊初值问题的解

研究了一阶线性微分方程模糊初值问题,利用模糊微分方程的刻画方程和初值之间的关系,给出了一阶线性微分方程模糊初值问题的一种求解方法,讨论了同基于Hukuhara微分求解方法之间的关系,证明了在一定条件下两种方法是等价的,文中的实例说明了这一点.     

Spline Techniques for the Numerical Solution of Singular Perturbation Problems

One-dimensional singularly-perturbed two-point boundary-value problems arising in various fields of science and engineering (for instance, fluid mechanics, quantum mechanics, optimal control, chemical reactor theory, aerodynamics, reaction-diffusion processes, geophysics, etc.) are treated. Either these problems exhibits boundary layer(s) at one or both ends of the underlying interval or they possess oscillatory behavior depending on the nature of the coefficient of the first derivative term. Some spline difference schemes are derived for these problems using splines in compression and splines in tension. Second-order uniform convergence is achieved for both kind of schemes. By making use of the continuity of the first-order derivative of the spline function, a tridiagonal system is obtained which can be solved efficiently by well-known algorithms. Numerical examples are given to illustrate the theory.     

一阶多参数模糊微分方程及定解问题

在单参数模糊微分方程基础上研究了一阶多参数模糊微分方程和模糊初值问题,利用刻画方程的解与刻画参数的关系给出了多参数模糊微分方程解存在的条件,最后给出了具体算例.表明,多参数模糊微分方程具有广泛的工程应用背景.     

几类三阶非线性常微分方程组边值问题正解的存在性

研究几类二阶非线性常微分方程组的边值问题,在合适的条件下,利用锥拉伸不动点定理获得了其正解的存在性.     

用逆微分算子法求n阶常系数线性一般非齐次微分方程特解公式

本文利用逆微分算子及其线性性质 ,给出了求 n阶常系数线性一般非齐次项微分方程特解公式 ,     

Asymptotic Expansions of the Cubic Spline Collocation Solution for Second-Order Ordinary Differential Equations

In this paper, we consider the following problem $$\begin{cases}u''(x)=f(x,u(x),u'(x)), a\leq x\leq b,\\u(a)=u(b)=0,\end{cases}$$ and obtain the theorem.