PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Pointwise convergence of Fourier-Laguerre series of integrable functions
Łenski W., Szal B.
Fasciculi Mathematici
|
2018
|
Nr 60
93--101
EN
We extend and improve the some results of Xh. Z. Krasniqi [Int. J. of Anal. and Appl. Vol. 1, 33-39 (2013)], M. L. Mittal and M. V. Singh [Operators, Int. J. of Analysis, Vol. 2015, Article ID 478345, 4 pages] and from many other papers on summability of Fourier-Laguerre series to strong summability proving the estimate of the deviation of the partial sums from considered functions. There also is a remark on summability methods used in cited papers.
2
Content available remote Point wise approximation of 2π/r-periodic functions by matrix operators of their Fourier series with r-differences of the entries
Łenski W., Szal B.
Demonstratio Mathematica
|
2018
|
Vol. 51, nr 1
309--322
EN
We extend the results of Xh. Z. Krasniqi [Acta Comment. Univ. Tartu. Math., 2013, 17, 89-101] and the authors [Acta Comment. Univ. Tartu. Math., 2009, 13, 11-24] to the case of 2π/r-periodic functions. More over, as a measure of approximation r-differences of the entries are used.
3
Content available remote On trigonometric approximation of functions in the Lq norm
Mohapatra R. N., Szal B.
Demonstratio Mathematica
|
2018
|
Vol. 51, nr 1
17--26
EN
In this paper we obtain a degree of approximation of functions in Lq by operators associated with their Fourier series using integral modulus of continuity. These results generalize many known results and are proved under less stringent conditions on the infinite matrix.
4
Content available remote On pointwise approximation of functions by some matrix means of conjugate Fourier series
Łenski W., Szal B.
Fasciculi Mathematici
|
2015
|
Nr 55
91--108
EN
The results corresponding to some theorems of S. Lal [Tamkang J. Math., 31(4)(2000), 279-288] and the results of the authors [Banach Center Publ. 92(2011), 237-247] are shown. The same degrees of pointwise approximation as in mentioned papers by significantly weaker assumptions on considered functions are obtained. From presented pointwise results the estimation on norm approximation with essentialy better degrees are derived. Some special cases as corollaries for iteration of the Norlund or the Riesz method with the Euler one are also formulated.
5
Content available remote Approximation of conjugate functions by general linear operators of their Fourier series at the Lebesgue points
Łenski W., Szal B.
Demonstratio Mathematica
|
2014
|
Vol. 47, nr 4
878--892
EN
The pointwise estimates of the deviations (…) and (…) in terms of moduli of continuity (…) and (…) are proved. Analogical results on norm approximation with remarks and corollary are also given. These results generalized a theorem of Mittal [3, Theorem 1, p. 437].
6
Content available remote Approximation of functions from IP {uj)p by linear operators of their Fourier series
Łenski W., Szal B.
Commentationes Mathematicae
|
2011
|
Vol. 51, [Z] 2
189-202
EN
We show the results corresponding to theorems of S. Lai [Appl. Math. Comput., 209 (2009) 346-350] on the rate of approximation of functions from the generalized integral Lipschitz classes by matrix summability means of their Fourier series as well as to the authors theorems [Acta Comment. Univ. Tartu. Math., 13 (2009), 11-24] also on such approximations.
7
Content available remote On the degree of strong approximation of functions and conjugate functions
Łenski W., Szal B.
Demonstratio Mathematica
|
2010
|
Vol. 43, nr 1
117-128
EN
We extend and generalize the results of the first author [4]. Considering additionally conjugate functions and introducing a new subclass of integrable functions we obtain the results of the L. Leindler [3] and P. Chandra [1, 2] type.
8
Content available remote Baire measurable solutions of a generalized Gołab-Schinzel equation
Szal B., Jabłońska E.
Commentationes Mathematicae
|
2010
|
Vol. 50, [Z] 1
69-72
EN
J. Brzdek [1] characterized Baire measurable solutions f : X →K of the functional equation f(x + f(x)n
9
Content available remote Application of the M RBV S classes to embedding relations of the Besov classes
Szal B.
Demonstratio Mathematica
|
2009
|
Vol. 42, nr 2
303-322
EN
L. Leindler obtained a necessary and sufficient condition in order to a function is an element of Lp having Fourier coefficients of rest bounded variation belong to the Besov class. In the present paper the analogue of this result is proved with function having Fourier coefficients of mean rest bounded variation. We also discuss embedding relations between the Besov classes.
10
Content available remote A note on the MRBSV S class and its application to the uniform convergence and boundedness of sine series
Szal B.
Commentationes Mathematicae
|
2009
|
Vol. 49, [Z] 1
67-79
EN
A new class of γ rest bounded second variation sequences is dened. Some relationships between classes of considered sequences are proved. The results of Leindler [3] and author [8] are extended to our new class.
11
Content available remote Pointwise strong and very strong approximation by matrix means of Fourier series
Łenski W., Szal B.
Commentationes Mathematicae
|
2008
|
Vol. 48, [Z] 2
177-198
EN
We generalize and extend the some results of the paper [6]. Considering a wider class of function and more general means we obtain the results of the V. Totik type [8, 9].
12
Content available remote A note on the uniform convergence and boundedness of a generalized class of sine series
Szal B.
Commentationes Mathematicae
|
2008
|
Vol. 48, [Z] 1
85-94
EN
In this paper we essentially extend the Leindler’s results concerning the uniform convergence and boundedness of a certain class of sine series.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.