共查询到20条相似文献,搜索用时 109 毫秒
1.
扩充的Hermite-Fejér插值算子平均收敛性 总被引:3,自引:0,他引:3
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Lpu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.
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
3.
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
4.
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
5.
关于二元函数的三角插值逼近 总被引:2,自引:0,他引:2
本文以两组不同的节点构造了一个组合型的二元三角插值多项式算子Lmn(f;x,y),并且研究了二元连续周期函数对这个算子的收敛性及收敛阶的估计等问题。 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.
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
8.
袁学刚 《纯粹数学与应用数学》2000,16(1):10-14
选取一组求和因子ρa,β构造了二重三角插值算子Fmn(f;y),使对于任意的f(x,y)∈C2π,2π都能在全面上一致收敛,且达到最佳收敛阶。 相似文献
9.
讨论了以第二类 Tchebycheff多项式的零点为插值结点纽的 Grǖnwald 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,说明了其于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 Grunwald插值,证明了其于 Lp(1≤p<∞)下是收敛的. 相似文献
10.
11.
The convergence behavior of the Picard iteration Xk+1=AXk+B and the weighted case Yk=Xk/bk is investigated. It is shown that the convergence of both these iterations is related to the so-called effective spectrum of A with respect to some matrix. As an application of our convergence results we discuss the convergence behavior of a sequence of scaled triangular matrices {DNTN }. 相似文献
12.
The aim of this paper is to introduce the vector space δF m(Ω). Equipping this space by a norm defined using the Hessian measure, we prove that it is a Banach space and that the class F m(Ω) is closed in it. Moreover we show that the topology defined by this norm is stronger than the convergence in Capm-capacity. At the end of this paper we prove a relationship between weak convergence and the convergence in capacity Capm,T in the class δSH m loc (Ω). 相似文献
13.
In this article, we introduce the concept of lacunary statistical convergence of order α of real number sequences and give some inclusion relations between the sets of lacunary statistical convergence of order α and strong Nθα(p)-summability. Furthermore, some relations between the spaces NθαSθα are examined. 相似文献
14.
Gerald Beer 《Set-Valued and Variational Analysis》1993,1(1):69-80
Let 2 X denote the closed subsets of a Hausdorff topological space <X, {gt}>. The Fell topology τF on 2 X has as a subbase all sets of the form {A ∈ 2 X :A ∩V ≠ 0}, whereV is an open subset ofX, plus all sets of the form {A ∈ 2 X :A ?W}, whereW has compact complement. The purpose of this article is two-fold. First, we characterize first and second countability for τF in terms of topological properties for τ. Second, we show that convergence of nets of closed sets with respect to the Fell topology parallels Attouch-Wets convergence for nets of closed subsets in a metric space. This approach to set convergence is highly tractable and is well-suited for applications. In particular, we characterize Fell convergence of nets of lower semicontinuous functions as identified with their epigraphs in terms of the convergence of sublevel sets. 相似文献
15.
In this paper we generalize two results of Khan and Majumdar on the weak sequential convergence of functions in the Lebesgue-Bochner space LX1(Ω) and on a Fatou-like convergence theorem. 相似文献
16.
Alfredo N. Iusem 《Acta Appl Math》1995,38(2):163-184
We analyze an algorithm for the problem minf(x) s.t.x 0 suggested, without convergence proof, by Eggermont. The iterative step is given by x
j
k+1
=x
j
k
(1-kf(x
k)j) with k > 0 determined through a line search. This method can be seen as a natural extension of the steepest descent method for unconstrained optimization, and we establish convergence properties similar to those known for steepest descent, namely weak convergence to a KKT point for a generalf, weak convergence to a solution for convexf and full convergence to the solution for strictly convexf. Applying this method to a maximum likelihood estimation problem, we obtain an additively overrelaxed version of the EM Algorithm. We extend the full convergence results known for EM to this overrelaxed version by establishing local Fejér monotonicity to the solution set.Research for this paper was partially supported by CNPq grant No 301280/86. 相似文献
17.
Sönke Blunck 《Journal of Functional Analysis》2002,195(2):350-370
We extend the Trotter-Kato-Chernoff theory of strong approximation of C0 semigroups on Banach spaces to operator-norm approximation of analytic semigroups with error estimate. As application we obtain a criterion for the operator-norm convergence of the Trotter product formula on Banach spaces with error estimate n−1 log n, provided one of the generators has a bounded H∞ functional calculus. For both results, we present versions for approximation in operator-ideal-norms such as the trace norm or the Hilbert-Schmidt norm. Finally, we give some remarks on the operator-norm convergence of the Trotter product formula for semigroups acting on a scale of Lp-spaces. 相似文献
18.
Ferenc Móricz 《Journal d'Analyse Mathématique》1994,62(1):115-130
We prove the convergence inL
1([−gp, π)2)-norm of the double Fourier series of an integrable functionf(x, y) which is periodic and even with respect tox andy, with coefficientsa
jk
satisfying certain conditions of Hardy-Karamata kind, and such thata
jk
logj logk→0 asj, k→∞. These sufficient conditions become quite natural in particular cases. Then we extend these results to the convergence
of double Walsh-Fourier series inL
1 (0, 1)2)- norm. As a by-product, we obtain Tauberian conditions ensuring the convergence of a double numerical series provided it
is Cesàro summable.
This research was partially supported by the Hungarian National Foundation for Scientific Research under Grant # 234. 相似文献
19.
It is well-known that only a single condition (called the admissibility condition) is sufficient for L 2-convergence of multiple continuous wavelet transforms (MCWT). However known results suggest that to guarantee the pointwise convergence of MCWT for L p -functions wavelets should vanish quite rapidly at infinity. In this article, we consider the class of nonseparable multiple wavelets with square-symmetric Fourier transforms. For these wavelets ψ we prove that the admissibility condition and the condition ψ∈L 1(R n ) are sufficient for the convergence of corresponding MCWT almost everywhere. 相似文献
20.
《Comptes Rendus de l'Academie des Sciences Series IIA Earth and Planetary Science》2001,332(4):339-344
Let (Zn) be a branching process in a random environment. If the process in sub-critical or critical, we study the convergence rate of the survival probability P(Zn>0) as n→∞; if the process is supercritical, we give a necessary and sufficient condition for the convergence in Lp of the natural martingale, where p>1 is given. 相似文献