Jafarov, Sadulla Z. Derivatives of trigonometric polynomials and converse theorem of the constructive theory of functions in Morrey spaces. (English) Zbl 1426.41015 Proc. Inst. Math. Mech., Natl. Acad. Sci. Azerb. 45, No. 1, 137-145 (2019). MSC: 41A25 41A17 41A28 42A10 PDF BibTeX XML Cite \textit{S. Z. Jafarov}, Proc. Inst. Math. Mech., Natl. Acad. Sci. Azerb. 45, No. 1, 137--145 (2019; Zbl 1426.41015)
Gadjev, I. A direct theorem for MKZ-Kantorovich operator. (English) Zbl 1438.41033 Anal. Math. 45, No. 1, 25-38 (2019). Reviewer: Ioan Raşa (Cluj-Napoca) MSC: 41A36 41A17 41A25 41A27 PDF BibTeX XML Cite \textit{I. Gadjev}, Anal. Math. 45, No. 1, 25--38 (2019; Zbl 1438.41033) Full Text: DOI
Draganov, Borislav R.; Gadjev, Ivan Approximation of functions by the Szász-Mirakjan-Kantorovich operator. (English) Zbl 1411.41017 Numer. Funct. Anal. Optim. 40, No. 7, 803-824 (2019). MSC: 41A36 41A17 41A25 41A27 PDF BibTeX XML Cite \textit{B. R. Draganov} and \textit{I. Gadjev}, Numer. Funct. Anal. Optim. 40, No. 7, 803--824 (2019; Zbl 1411.41017) Full Text: DOI
Gadjev, Ivan Approximation of functions by some exponential-type operators. (English) Zbl 1445.41013 Ivanov, Kamen (ed.) et al., Constructive theory of functions. Proceedings of the 12th international conference, Sozopol, Bulgaria, June 11–17, 2016. Sofia: Prof. Marin Drinov Academic Publishing House. 143-158 (2018). MSC: 41A36 41A17 41A25 41A27 PDF BibTeX XML Cite \textit{I. Gadjev}, in: Constructive theory of functions. Proceedings of the 12th international conference, Sozopol, Bulgaria, June 11--17, 2016. Sofia: Prof. Marin Drinov Academic Publishing House. 143--158 (2018; Zbl 1445.41013) Full Text: Link
Gadjev, Ivan Approximation of functions by Baskakov-Kantorovich operator. (English) Zbl 1351.41022 Result. Math. 70, No. 3-4, 385-400 (2016). MSC: 41A36 41A25 41A27 41A17 PDF BibTeX XML Cite \textit{I. Gadjev}, Result. Math. 70, No. 3--4, 385--400 (2016; Zbl 1351.41022) Full Text: DOI
Gadjev, Ivan Weighted approximation by Baskakov operators. (English) Zbl 1329.41032 Math. Inequal. Appl. 18, No. 4, 1443-1461 (2015). MSC: 41A36 41A25 41A27 41A17 PDF BibTeX XML Cite \textit{I. Gadjev}, Math. Inequal. Appl. 18, No. 4, 1443--1461 (2015; Zbl 1329.41032) Full Text: DOI
Zapryanova, Teodora On approximation by algebraic version of the trigonometric Jackson integrals \(G_{S, N}\) in weighted integral metric. (English) Zbl 1416.41035 Ivanov, Kamen (ed.) et al., Constructive theory of functions. Dedicated to Blagovest Sendov and to the memory of Vasil Popov. Proceedings of the 11th international conference, Sozopol, Bulgaria, June 9–14, 2013. Sofia: Prof. Marin Drinov Academic Publishing House. 265-273 (2014). MSC: 41A36 41A17 41A25 PDF BibTeX XML Cite \textit{T. Zapryanova}, in: Constructive theory of functions. Dedicated to Blagovest Sendov and to the memory of Vasil Popov. Proceedings of the 11th international conference, Sozopol, Bulgaria, June 9--14, 2013. Sofia: Prof. Marin Drinov Academic Publishing House. 265--273 (2014; Zbl 1416.41035)
Heilmann, Margareta; Wagner, Martin Strong converse results for Baskakov-Durrmeyer operators. (English) Zbl 1430.41015 Nikolov, Geno (ed.) et al., Constructive theory of functions. In memory of Borislav Bojanov. Papers from the international conference, Sozopol, Bulgaria, June 3–10, 2010. Sofia: Prof. Marin Drinov Academic Publishing House. 141-149 (2012). MSC: 41A36 41A17 41A27 PDF BibTeX XML Cite \textit{M. Heilmann} and \textit{M. Wagner}, in: Constructive theory of functions. In memory of Borislav Bojanov. Papers from the international conference, Sozopol, Bulgaria, June 3--10, 2010. Sofia: Prof. Marin Drinov Academic Publishing House. 141--149 (2012; Zbl 1430.41015)
Ivanov, K. G.; Parvanov, P. E. Weighted approximation by Baskakov-type operators. (English) Zbl 1249.41059 Acta Math. Hung. 133, No. 1-2, 33-57 (2011). Reviewer: Daniel Cardenas-Morales (Jaen) MSC: 41A36 41A17 41A25 41A27 PDF BibTeX XML Cite \textit{K. G. Ivanov} and \textit{P. E. Parvanov}, Acta Math. Hung. 133, No. 1--2, 33--57 (2011; Zbl 1249.41059) Full Text: DOI
Akgün, Ramazan Inequalities for one sided approximation in Orlicz spaces. (English) Zbl 1234.26010 Hacet. J. Math. Stat. 40, No. 2, 231-240 (2011). MSC: 26A33 41A17 42A10 PDF BibTeX XML Cite \textit{R. Akgün}, Hacet. J. Math. Stat. 40, No. 2, 231--240 (2011; Zbl 1234.26010)
Akgün, Ramazan; Kokilashvili, Vakhtang The refined direct and converse inequalities of trigonometric approximation in weighted variable exponent Lebesgue spaces. (English) Zbl 1229.26012 Georgian Math. J. 18, No. 3, 399-423 (2011). MSC: 26A33 41A17 42A10 PDF BibTeX XML Cite \textit{R. Akgün} and \textit{V. Kokilashvili}, Georgian Math. J. 18, No. 3, 399--423 (2011; Zbl 1229.26012) Full Text: DOI
Akgün, Ramazan; Kokilashvili, Vakhtang On converse theorems of trigonometric approximation in weighted variable exponent Lebesgue spaces. (English) Zbl 1206.42002 Banach J. Math. Anal. 5, No. 1, 70-82 (2011). Reviewer: Mehdi Hassani (Zanjan) MSC: 42A10 26A33 41A17 41A20 PDF BibTeX XML Cite \textit{R. Akgün} and \textit{V. Kokilashvili}, Banach J. Math. Anal. 5, No. 1, 70--82 (2011; Zbl 1206.42002) Full Text: DOI EuDML EMIS
Heilmann, Margareta; Wagner, Martin Strong converse results for Bernstein-Durrmeyer operators and their quasi-interpolants. (English) Zbl 1212.41017 Gen. Math. 18, No. 1, 55-70 (2010). Reviewer: Zoltán Finta (Cluj-Napoca) MSC: 41A10 41A17 41A27 41A36 41A44 PDF BibTeX XML Cite \textit{M. Heilmann} and \textit{M. Wagner}, Gen. Math. 18, No. 1, 55--70 (2010; Zbl 1212.41017)
Akgün, R. Sharp Jackson and converse theorems of trigonometric approximation in weighted Lebesgue spaces. (English) Zbl 1197.41007 Proc. A. Razmadze Math. Inst. 152, 1-18 (2010). MSC: 41A17 41A25 41A27 41A10 42A16 26A33 PDF BibTeX XML Cite \textit{R. Akgün}, Proc. A. Razmadze Math. Inst. 152, 1--18 (2010; Zbl 1197.41007) Full Text: Link
Ivanov, Kamen G.; Parvanov, Parvan E. Weighted approximation by the Goodman-Sharma operators. (English) Zbl 1381.41022 East J. Approx. 15, No. 4, 473-486 (2009). MSC: 41A36 41A27 41A10 41A25 41A17 PDF BibTeX XML Cite \textit{K. G. Ivanov} and \textit{P. E. Parvanov}, East J. Approx. 15, No. 4, 473--486 (2009; Zbl 1381.41022)
Finta, Zoltán On direct and converse approximation theorems. (English) Zbl 1212.41040 Cobzaş, Ştefan (ed.), Topics in mathematics, computer science and philosophy. A Festschrift for Wolfgang W. Breckner on his 65th anniversary. Cluj-Napoca: Cluj University Press (ISBN 978-973-610-672-9). 95-105 (2008). MSC: 41A17 PDF BibTeX XML Cite \textit{Z. Finta}, in: Topics in mathematics, computer science and philosophy. A Festschrift for Wolfgang W. Breckner on his 65th anniversary. Cluj-Napoca: Cluj University Press. 95--105 (2008; Zbl 1212.41040)
Dai, Feng Jackson-type inequality for doubling weights on the sphere. (English) Zbl 1116.41010 Constructive Approximation 24, No. 1, 91-112 (2006). Reviewer: Francisco Perez Acosta (La Laguna) MSC: 41A10 41A17 41A63 PDF BibTeX XML Cite \textit{F. Dai}, Constr. Approx. 24, No. 1, 91--112 (2006; Zbl 1116.41010) Full Text: DOI
Berisha, M. Q.; Berisha, F. M. A note on the inverse theorem for a generalised modulus of smoothness. (English) Zbl 1274.42001 Mat. Bilt. 25, 91-96 (2001). MSC: 42A05 42A10 PDF BibTeX XML Cite \textit{M. Q. Berisha} and \textit{F. M. Berisha}, Mat. Bilt. 25, 91--96 (2001; Zbl 1274.42001) Full Text: arXiv