caa a22 4500 605522502 CHVBK 20210128105158.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s10958-015-2405-6 doi (NATIONALLICENCE)springer-10.1007/s10958-015-2405-6 Approximation of Periodic Functions by Modified Steklov Averages in L 2 [Elektronische Daten] [V. Dron', V. Zhuk] In the space L 2 of periodic functions, sharp (in the sense of constants) lower estimates for the deviation of the modified Steklov functions of the first and second orders in terms of the modulus of continuity are established. Similar results are also obtained for even continuous periodic functions with nonnegative Fourier coefficients in the space C. Bibliography: 3 titles. Springer Science+Business Media New York, 2015 Dron' V. St. Petersburg State University, St. Petersburg, Russia aut Zhuk V. St. Petersburg State University, St. Petersburg, Russia aut Journal of Mathematical Sciences Springer US; http://www.springer-ny.com 207/6(2015-06-01), 815-824 1072-3374 207:6<815 2015 207 10958 https://doi.org/10.1007/s10958-015-2405-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10958-015-2405-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dron' V. St. Petersburg State University, St. Petersburg, Russia aut NATIONALLICENCE 700 1- Zhuk V. St. Petersburg State University, St. Petersburg, Russia aut NATIONALLICENCE 773 0- Journal of Mathematical Sciences Springer US; http://www.springer-ny.com 207/6(2015-06-01), 815-824 1072-3374 207:6<815 2015 207 10958 SWISSBIB 462951391