Year 2024,
Volume: 7 Issue: 4, 180 - 195, 15.12.2024
Rumen Uluchev
,
Ivan Gadjev
,
Parvan Parvanov
Project Number
BG-RRP-2.004-0008
References
- A. M. Acu, P. Agrawal: Better approximation of functions by genuine Bernstein-Durrmeyer type operators, Carpathian J. Math., 35 (2) (2019), 125–136.
- A. M. Acu, I. Rasa: New estimates for the differences of positive linear operators, Numer. Algorithms, 73 (3) (2016), 775–789.
- H. Berens, Y. Xu: On Bernstein-Durrmeyer polynomials with Jacobi weights, In Approximation Theory and Functional Analysis, (Edited by C. K. Chui), pp. 25–46, Acad. Press, Boston (1991).
- L. Beutel, H. Gonska and D. Kacsó: Variation-diminishing splines revised, In Proceedings of International Symposium on Numerical Analysis and Approximation Theory, (Edited by R. Trâmbi¸ta¸s), pp. 54–75, Presa Universitar˘a Clujean˘a, Cluj-Napoka (2002).
- W. Chen: On the modified Bernstein-Durrmeyer operator, Report of the Fifth Chinese Conference on Approximation Theory, Zhen Zhou (China), (1987).
- Z. Ditzian, K. G. Ivanov: Strong converse inequalities, J. Anal. Math., 61 (1993), 61–111.
- H. Gonska, R. P˘alt˘anea: Simultaneous approximation by a class of Bernstein-Durrmeyer operators preserving linear functions, Czechoslovak Math. J., 60 (135) (2010), 783–799.
- H. Gonska, R. P˘alt˘anea: Quantitative convergence theorems for a class of Bernstein-Durrmeyer operators preserving linear functions, Ukrainian Math. J., 62 (2010), 913–922.
- T. N. T. Goodman, A. Sharma: A modified Bernstein-Schoenberg operator, In Constructive Theory of Functions, Varna 1987, (Edited by Bl. Sendov et al.), pp. 166–173, Publ. House Bulg. Acad. of Sci., Sofia, (1988).
- T. N. T. Goodman, A. Sharma: A Bernstein-type operator on the simplex, Math. Balkanica (New Series), 5 (2) (1991), 129–145.
- K. G. Ivanov, P. E. Parvanov: Weighted approximation by the Goodman-Sharma operators, East J. Approx., 15 (4) (2009), 473–486.
- G. G. Lorentz: Bernstein Polynomials, Mathematical Expositions 8, University of Toronto Press, (1953).
- R. P˘alt˘anea: A class of Durrmeyer type operators preserving linear functions, Ann. Tiberiu Popoviciu Semin. Funct. Equ. Approx. Convexity, 5 (2007), 109–117.
- P. E. Parvanov, B. D. Popov: The limit case of Bernstein’s operators with Jacobi weights, Math. Balkanica (N.S.), 8 (2–3) (1994), 165–177.
Higher order approximation of functions by modified Goodman-Sharma operators
Year 2024,
Volume: 7 Issue: 4, 180 - 195, 15.12.2024
Rumen Uluchev
,
Ivan Gadjev
,
Parvan Parvanov
Abstract
Here we study the approximation properties of a modified Goodman-Sharma operator recently considered by Acu and Agrawal in [1]. This operator is linear but not positive. It has the advantage of a higher order of approximation of functions compared with the Goodman-Sharma operator. We prove direct and strong converse theorems in terms of a related K-functional.
Project Number
BG-RRP-2.004-0008
Thanks
This study is financed by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project No. BG-RRP-2.004-0008.
References
- A. M. Acu, P. Agrawal: Better approximation of functions by genuine Bernstein-Durrmeyer type operators, Carpathian J. Math., 35 (2) (2019), 125–136.
- A. M. Acu, I. Rasa: New estimates for the differences of positive linear operators, Numer. Algorithms, 73 (3) (2016), 775–789.
- H. Berens, Y. Xu: On Bernstein-Durrmeyer polynomials with Jacobi weights, In Approximation Theory and Functional Analysis, (Edited by C. K. Chui), pp. 25–46, Acad. Press, Boston (1991).
- L. Beutel, H. Gonska and D. Kacsó: Variation-diminishing splines revised, In Proceedings of International Symposium on Numerical Analysis and Approximation Theory, (Edited by R. Trâmbi¸ta¸s), pp. 54–75, Presa Universitar˘a Clujean˘a, Cluj-Napoka (2002).
- W. Chen: On the modified Bernstein-Durrmeyer operator, Report of the Fifth Chinese Conference on Approximation Theory, Zhen Zhou (China), (1987).
- Z. Ditzian, K. G. Ivanov: Strong converse inequalities, J. Anal. Math., 61 (1993), 61–111.
- H. Gonska, R. P˘alt˘anea: Simultaneous approximation by a class of Bernstein-Durrmeyer operators preserving linear functions, Czechoslovak Math. J., 60 (135) (2010), 783–799.
- H. Gonska, R. P˘alt˘anea: Quantitative convergence theorems for a class of Bernstein-Durrmeyer operators preserving linear functions, Ukrainian Math. J., 62 (2010), 913–922.
- T. N. T. Goodman, A. Sharma: A modified Bernstein-Schoenberg operator, In Constructive Theory of Functions, Varna 1987, (Edited by Bl. Sendov et al.), pp. 166–173, Publ. House Bulg. Acad. of Sci., Sofia, (1988).
- T. N. T. Goodman, A. Sharma: A Bernstein-type operator on the simplex, Math. Balkanica (New Series), 5 (2) (1991), 129–145.
- K. G. Ivanov, P. E. Parvanov: Weighted approximation by the Goodman-Sharma operators, East J. Approx., 15 (4) (2009), 473–486.
- G. G. Lorentz: Bernstein Polynomials, Mathematical Expositions 8, University of Toronto Press, (1953).
- R. P˘alt˘anea: A class of Durrmeyer type operators preserving linear functions, Ann. Tiberiu Popoviciu Semin. Funct. Equ. Approx. Convexity, 5 (2007), 109–117.
- P. E. Parvanov, B. D. Popov: The limit case of Bernstein’s operators with Jacobi weights, Math. Balkanica (N.S.), 8 (2–3) (1994), 165–177.