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1.
扩充的Hermite—Fejer插值算子平均收敛性   总被引:2,自引:0,他引:2  
文成林  张书玲 《数学学报》1999,42(3):429-440
讨论了以Jacobi正交多项式零点为插值结点的扩充Hermite-Fejer插值算子在Lu^p空间的平均收敛性。首先给出了算子加权平均收敛的条件,进一步得到了收敛阶。  相似文献   

2.
本文给出Hermite-Fejér插值的若干收敛准则.其中之一是:Hermite-Fejer插值算子对每一个连续函数一致收敛当且仅当该算子范数一致有界且该算子对两个单项式x及x2一致收敛.  相似文献   

3.
给出了以第二类Chebyrshev多项式的零点为插值结点组的一种拟Grünwald插值多项式在加权Lp范数下收敛速度的一个估计,并证明了其在弱渐近阶的意义下是精确的.这个结论说明了拟Grünwald插值算子在加权Lp意义下是收敛算子列.  相似文献   

4.
给出了以第二类Chebyshev多项式的零点为插值结点组的一种拟Grǖnwald插值多项式在加权Lp范数下收敛速度的一个估计,并证明了其在弱渐近阶的意义下是精确的.这个结论说明了拟Grǖnwald插值算子在加权Lp意义下是收敛算子列.  相似文献   

5.
张铁 《应用数学学报》2000,23(1):154-158
本文首先将证明矩形剖分单元上的Lobatto点,Gauss点和拟Lobatto点分别是二维投影型插值算子函数,梯度和二阶导数的逼近佳点;然后考虑了二阶椭圆边值问题的有限元近似.通过建立投影型插值算子各种形式的超收敛基本估计,证明了投影型插值算子的各类...  相似文献   

6.
讨论了以第二类Tchebycheff多项式的零点为插值结点组的Grünwald插值于Lp下的收敛性.当1≤p<2时,给出了收敛速度的一个精确估计;当p≥2时,说明了其Lp下不是收敛算子列.给出了一种以第二类Tchebycheff多项式的零点为插值结点组的修改的Grünwald插值,证明了其于Lp(1≤p<∞)下是收敛的.  相似文献   

7.
本文首先介绍了三维投影型插值算子,并通过这个算子导出了三三次长方体有限元的弱估计.然后,利用离散导数Green函数的W^2,1半范估计和弱估计证明了有限元uh的梯度和三三次投影型插值Пh^2u的梯度在逐点意义下有超逼近.最后,将这种超逼近用于超收敛分析并导出了有限元的整体超收敛估计.  相似文献   

8.
盛宝怀  尚增科 《数学杂志》1994,14(3):413-423
本文引进了Kantorovitch算子型的二元修正Jackson三角插值多项式,给出了其在Orlicz空间中的收敛阶,作了推论,给出了二元修正Hermite-Fejer插值算子在带Orlicz空间中的逼近的量化估计。  相似文献   

9.
矩形元上插值算子压缩性质及有限元迭代校正   总被引:2,自引:0,他引:2  
王凯 《数学杂志》2001,21(3):319-328
本文研究了矩形上插值算子的性质,证明了一维及二维情形下插值算子具有压缩性,从而证明了矩形元上有限元迭代校正解收敛,并对几种不同类型的L型区域给出了数值例子,最后对三维及三维就以上情形作出了讨论。  相似文献   

10.
讨论了一种组合型Lagrange三角插值多项式算子H_n(f;r,x)给出了它在Ba空间中的收敛速度.  相似文献   

11.
广义函数Denjoy积分的收敛性问题   总被引:2,自引:0,他引:2  
本文讨论广义函数De njoy积分的收敛性问题.首先给出了广义Denjoy可积函数空间中强收敛、弱收敛、弱~*收敛和广义函数Denjoy积分收敛的关系;证明拟一致收敛是广义函数Denjoy积分收敛的一个充分必要条件;最后指出了Denjoy可积广义函数列弱~*收敛与强收敛等价当且仅当原函数等度连续.  相似文献   

12.
In this paper we investigate how three well-known modes of convergence for (real-valued) functions are related to one another. In particular, we consider order convergence, pointwise convergence and continuous convergence of sequences of nearly finite normal lower semi-continuous functions. There is a natural comparison to be made between the results we obtain for convergence of sequences of semi-continuous functions, and classic results on the convergence of sequences of measurable functions.  相似文献   

13.
In this paper we prove some convergence theorems for Banach space valued multifunctions. First we consider the notion of weak convergence of sets and prove a weak completeness and a weak compactness result of the Dunford-Pettis type for weakly compact, convex valued integrable multifunctions. Then we consider set valued martingales and establish two convergence theorems. One using the Kuratowski-Mosco mode of convergence and for the other the Hausdorff mode.  相似文献   

14.
The construction of initial conditions of an iterative method is one of the most important problems in solving nonlinear equations. In this paper, we obtain relationships between different types of initial conditions that guarantee the convergence of iterative methods for simultaneously finding all zeros of a polynomial. In particular, we show that any local convergence theorem for a simultaneous method can be converted into a convergence theorem with computationally verifiable initial conditions which is of practical importance. Thus, we propose a new approach for obtaining semilocal convergence results for simultaneous methods via local convergence results.  相似文献   

15.
We present a unified derivation of affine invariant convergence results for Newton's method. Initially we derive affine invariant forms of the perturbation lemma and a mean value theorem. With their aid we obtain an optimal radius of convergence for Newton's method, from which further radius of convergence estimates follow. From the Newton-Kantorovitch theorem we derive other estimates of the radius of convergence. We discuss estimation of the parameters in the expressions we have derived.  相似文献   

16.
In this paper we develop the main aspects of the Bohman–Korovkin theorem on approximation of continuous functions with the use of A-statistical convergence and matrix summability method which includes both convergence and almost convergence. Since statistical convergence and almost convergence methods are incompatible we conclude that these methods can be used alternatively to get some approximation results.  相似文献   

17.
In this paper, we will show a new weighted equi-statistical convergence and based on this definition we will prove a kind of the Korovkin type theorems. Also we will show the rate of the convergence for this kind of weighted statistical convergence and Voronovskaya type theorem.  相似文献   

18.

We develop a matrix form of the Nelder-Mead simplex method and show that its convergence is related to the convergence of infinite matrix products. We then characterize the spectra of the involved matrices necessary for the study of convergence. Using these results, we discuss several examples of possible convergence or failure modes. Then, we prove a general convergence theorem for the simplex sequences generated by the method. The key assumption of the convergence theorem is proved in low-dimensional spaces up to 8 dimensions.

  相似文献   

19.
In this paper, we mainly discuss the measurable functional spaces based on strict pseudo-additions. Particularly, we obtained the some important theorems for the measurable functional spaces based on a strict pseudo-addition. Furthermore, we got that the some properties of the sequence of a.e. convergence and convergence in $\oplus$-measure, and the relationship between a.e. convergence and convergence in $\oplus$-measure on the measurable functional spaces based on a strict pseudo-addition.  相似文献   

20.
We briefly recall the concept of multiscale convergence, which is a generalization of two-scale convergence. Then we investigate a related concept, called very weak multiscale convergence, and prove a compactness result with respect to this type of convergence. Finally we illustrate how this result can be used to study homogenization problems with several scales of oscillations.  相似文献   

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