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1.
徐应祥 《应用数学与计算数学学报》2009,23(2):1-8
以二次紧支撑样条小波为基函数,构造了一类二次紧支撑样条小波插值函数,仔细讨论了其计算过程和误差.再将其应用于数值积分,给出了一类求数值积分的新公式,分析了其误差,最后给出一个数值例子. 相似文献
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木文给出矩形域上双三次叠样条插值问题的提法、计算格式及误差的渐近展式.并且基于双三次叠样条插值构造了一个高精度的数值积分公式,它是三次叠样条数值积分公式的一个推广. 相似文献
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一类基于小波基函数插值的有限元方法 总被引:8,自引:0,他引:8
在分析具有大的梯度问题中,将具有紧支集的小波基函数引入到传统的有限元插值函数的构造中,对传统的插值方法进行修正。对新的插值模式进行了数值稳定性(解的唯一存在性)分析并通过分片分析讨论了解的收敛性,新的插值模式所引入的附加自由度通过静力凝聚法来消除,最后得到了基于变分原理的小波有限元列式。 相似文献
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衣娜 《高等学校计算数学学报》2010,32(3)
<正>1二元三次一阶光滑样条函数二元样条函数空间在数值逼近、曲面拟合、有限元方法(FEM)、散乱数据插值、多元数值积分、微分和积分方程数值解、计算机辅助几何设计(CAGD)、计算机图形学、信号过程和数学模型等领域有着广泛的应用.而空间S_3~1(Δ)除了二元三次样条函数具有的计 相似文献
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将三次样条理论与再生核理论相结合,利用再生核函数巧妙地构造了三次样条函数空间的一组基底.基于三次样条插值的高收敛特点,得到了微分方程边值问题近似解的一种新的求解方法.数值算例展现出算法简单、有效. 相似文献
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The objective of this paper is to introduce a general scheme for the construction of interpolatory approximation formulas and compactly supported wavelets by using spline functions with arbitrary (nonuniform) knots. Both construction procedures are based on certain ``optimally local' interpolatory fundamental spline functions which are not required to possess any approximation property.
12.
A general procedure for constructing multivariate non-tensor-product wavelets that generate an orthogonal decomposition ofL
2(R)s,s s≥1, is described and applied to yield explicit formulas for compactly supported spline-wavelets based on the multiresolution
analysis ofL
2(R)s 1≤s≤3, generated by any box spline whose direction set constitutes a unimodular matrix. In particular, when univariate cardinal
B-splines are considered, the minimally supported cardinal spline-wavelets of Chui and Wang are recovered. A refined computational
scheme for the orthogonalization of spaces with compactly supported wavelets is given. A recursive approximation scheme for
“truncated” decomposition sequences is developed and a sharp error bound is included. A condition on the symmetry or anti-symmetry
of the wavelets is applied to yield symmetric box-spline wavelets.
Partially supported by ARO Grant DAAL 03-90-G-0091
Partially supported by NSF Grant DMS 89-0-01345
Partially supported by NATO Grant CRG 900158. 相似文献
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It is more difficult to construct 3-D splines than in 2-D case. Some results in the three directional meshes of bivariate
case have been extended to 3-D case and corresponding tetrahedron partition has been constructed. The support of related B-splines
and their recurrent formulas on integration and differentiation-difference are obtained. The results of this paper can be
extended into higher dimension spaces, and can be also used in wavelet analysis, because of the relationship between spline
and wavelets. 相似文献
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本文利用 Euler-Maclaurin求和公式构造了一类求积公式 ,称为修正复合梯形公式 .它和复合梯形公式的求积节点及计算量是一样的 ,但收敛阶有很大的提高 ,特别适合于计算带有各种类型小波的数值积分 . 相似文献
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Based on collocation with Haar and Legendre wavelets, two efficient and new numerical methods are being proposed for the numerical solution of elliptic partial differential equations having oscillatory and non-oscillatory behavior. The present methods are developed in two stages. In the initial stage, they are developed for Haar wavelets. In order to obtain higher accuracy, Haar wavelets are replaced by Legendre wavelets at the second stage. A comparative analysis of the performance of Haar wavelets collocation method and Legendre wavelets collocation method is carried out. In addition to this, comparative studies of performance of Legendre wavelets collocation method and quadratic spline collocation method, and meshless methods and Sinc–Galerkin method are also done. The analysis indicates that there is a higher accuracy obtained by Legendre wavelets decomposition, which is in the form of a multi-resolution analysis of the function. The solution is first found on the coarse grid points, and then it is refined by obtaining higher accuracy with help of increasing the level of wavelets. The accurate implementation of the classical numerical methods on Neumann’s boundary conditions has been found to involve some difficulty. It has been shown here that the present methods can be easily implemented on Neumann’s boundary conditions and the results obtained are accurate; the present methods, thus, have a clear advantage over the classical numerical methods. A distinct feature of the proposed methods is their simple applicability for a variety of boundary conditions. Numerical order of convergence of the proposed methods is calculated. The results of numerical tests show better accuracy of the proposed method based on Legendre wavelets for a variety of benchmark problems. 相似文献
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《Journal of Approximation Theory》2003,120(1):1-19
We give a formula for the duals of the masks associated with trivariate box spline functions. We show how to construct trivariate nonseparable compactly supported biorthogonal wavelets associated with box spline functions. The biorthogonal wavelets may have arbitrarily high regularities. 相似文献
17.
Rong-Qing Jia 《Advances in Computational Mathematics》2009,30(2):177-200
In this paper we investigate spline wavelets on the interval with homogeneous boundary conditions. Starting with a pair of
families of B-splines on the unit interval, we give a general method to explicitly construct wavelets satisfying the desired
homogeneous boundary conditions. On the basis of a new development of multiresolution analysis, we show that these wavelets
form Riesz bases of certain Sobolev spaces. The wavelet bases investigated in this paper are suitable for numerical solutions
of ordinary and partial differential equations.
Supported in part by NSERC Canada under Grant OGP 121336. 相似文献
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In this article, we introduce vector-valued multiresolution analysis and the biorthogonal vector-valued wavelets with four-scale. The existence of a class of biorthogonal vector-valued wavelets with compact support associated with a pair of biorthogonal vector-valued scaling functions with compact support is discussed. A method for designing a class of biorthogonal compactly supported vector-valued wavelets with four-scale is proposed by virtue of multiresolution analysis and matrix theory. The biorthogonality properties concerning vector-valued wavelet packets are characterized with the aid of time–frequency analysis method and operator theory. Three biorthogonality formulas regarding them are presented. 相似文献
19.
Summary. We generalize earlier results concerning
an asymptotic error expansion of wavelet
approximations. The properties of the monowavelets,
which are the building
blocks for the error expansion, are studied in more
detail, and connections
between spline wavelets and Euler and
Bernoulli polynomials are pointed out.
The expansion is used to compare the
error for different wavelet families.
We prove that the leading terms of the
expansion only depend on the multiresolution
subspaces and not
on how the complementary subspaces
are chosen.
Consequently, for a fixed set of
subspaces , the leading
terms do not depend on the fact whether
the wavelets are orthogonal or not.
We also show that Daubechies' orthogonal wavelets need,
in general, one level more than spline wavelets to obtain an
approximation with a prescribed accuracy.
These results are illustrated with numerical examples.
Received May 3, 1993 / Revised version received January 31, 1994 相似文献
20.
有限区间内四阶样条小波的构造 总被引:3,自引:0,他引:3
用有限区间上的截断4阶B样条,构造了有限区间上的4阶样条小波。这些小波由边界小波和内部小波组成,对某一尺度,它们组成了有限维的小波空间。于是,任何有限区间上的函数皆可表示为该区间上的尺度函数和小波函数的有限和,即小波级数,这克服了用无穷区间上的小波进行有限信号处理时,在边界上误差较大的不足,同时将该小波用于偏微分方程具有同样重要的意义。 相似文献