On Jackson-type inequalities associated with separable Haar wavelets

Author(s):  
P. Andrianov ◽  
M. Skopina

Uniform approximation of multivariate periodic functions by Haar polynomials is studied. A general sharp Jackson type inequality and its refinement for certain types of numbers [Formula: see text] are discussed. An interesting phenomenon appears for some numbers [Formula: see text]: a sharp estimate is not unique.

2014 ◽  
Vol 51 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Dawei Hong ◽  
Shushuang Man ◽  
Jean-Camille Birget ◽  
Desmond S. Lun

We construct a wavelet-based almost-sure uniform approximation of fractional Brownian motion (FBM) (Bt(H))_t∈[0,1] of Hurst index H ∈ (0, 1). Our results show that, by Haar wavelets which merely have one vanishing moment, an almost-sure uniform expansion of FBM for H ∈ (0, 1) can be established. The convergence rate of our approximation is derived. We also describe a parallel algorithm that generates sample paths of an FBM efficiently.


1988 ◽  
Vol 43 (6) ◽  
pp. 435-443 ◽  
Author(s):  
A. A. Ligun

2010 ◽  
Vol 130 (3) ◽  
pp. 254-285 ◽  
Author(s):  
Z. Ditzian ◽  
A. Prymak

2014 ◽  
Vol 38 (24) ◽  
pp. 6031-6037 ◽  
Author(s):  
Shaobo Lin ◽  
Yuanhua Rong ◽  
Zongben Xu

Author(s):  
Barnabás Bede ◽  
◽  
Hajime Nobuhara ◽  
János Fodor ◽  
Kaoru Hirota ◽  
...  

In crisp approximation theory the operations that are used are only the usual sum and product of reals. We propose the following problem: are sum and product the only operations that can be used in approximation theory? As an answer to this problem we propose max-product Shepard approximation operators and we prove that these operators have very similar properties to those provided by the crisp approximation theory. In this sense we obtain uniform approximation theorem of Weierstrass type, and Jackson-type error estimate in approximation by these operators.


2018 ◽  
Vol 51 (1) ◽  
pp. 141-150
Author(s):  
Sergey S. Volosivets ◽  
Anna A. Tyuleneva

Abstract For 2π-periodic functions from Lp (where 1 < p < ∞) we prove an estimate of approximation by Euler means in Lp metric generalizing a result of L. Rempuska and K. Tomczak. Furthermore, we show that this estimate is sharp in a certain sense. We study the uniform approximation of functions by Euler means in terms of their best approximations in p-variational metric and also prove the sharpness of this estimate under some conditions. Similar problems are treated for conjugate functions.


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