scholarly journals Pointwise estimates for monotone polynomial approximation

1985 ◽  
Vol 1 (1) ◽  
pp. 323-331 ◽  
Author(s):  
Ronald A. DeVore ◽  
Xiang Ming Yu

2018 ◽  
Vol 459 (2) ◽  
pp. 1260-1295 ◽  
Author(s):  
K.A. Kopotun ◽  
D. Leviatan ◽  
I.A. Shevchuk


Author(s):  
Jia-Ding Cao ◽  
Heinz H. Gonska

AbstractDeVore-Gopengauz-type operators have attracted some interest over the recent years. Here we investigate their relationship to shape preservation. We construct certain positive convolution-type operators Hn, s, j which leave the cones of j-convex functions invariant and give Timan-type inequalities for these. We also consider Boolean sum modifications of the operators Hn, s, j show that they basically have the same shape preservation behavior while interpolating at the endpoints of [−1, 1], and also satisfy Telyakovskiῐ- and DeVore-Gopengauz-type inequalities involving the first and second order moduli of continuity, respectively. Our results thus generalize related results by Lorentz and Zeller, Shvedov, Beatson, DeVore, Yu and Leviatan.





2016 ◽  
Vol 68 (1) ◽  
pp. 109-128 ◽  
Author(s):  
Kirill Kopotun ◽  
Dany Leviatan ◽  
Igor Shevchuk

AbstractIn this paper, we prove that for ℓ = 1 or 2 the rate of best ℓ- monotone polynomial approximation in the Lp norm (1 ≤ p ≤) weighted by the Jacobi weight with , is bounded by an appropriate (ℓ + 1)-st modulus of smoothness with the same weight, and that this rate cannot be bounded by the (ℓ + 2)-nd modulus. Related results on constrained weighted spline approximation and applications of our estimates are also given.





Author(s):  
K. A. Kopotun ◽  
D. Leviatan ◽  
I. L. Petrova ◽  
I. A. Shevchuk


1992 ◽  
Vol 59 (3-4) ◽  
pp. 395-399 ◽  
Author(s):  
S. G. Gal ◽  
J. Szabados








Sign in / Sign up

Export Citation Format

Share Document