56290 20200221144208.0 doi 10.1186/s13660-016-1078-0 sideral 95195 ART-2016-95195 eng (orcid)0000-0001-8331-5160 Adell, J.A. Universidad de Zaragoza Towards the best constant in front of the Ditzian-Totik modulus of smoothness 2016 Access copy available to the general public Unrestricted We give accurate estimates for the constants (Formula presented.), where I = R or I = 0, 8), Ln is a positive linear operator acting on real functions f defined on the interval I, A(I) is a certain subset of such function, and ¿s 2(f; ·) is the Ditzian-Totik modulus of smoothness of f with weight function s. This is done under the assumption that s is concave and satisfies some simple boundary conditions at the endpoint of I, if any. Two illustrative examples closely connected are discussed, namely, Weierstrass and Szàsz-Mirakyan operators. In the first case, which involves the usual second modulus, we obtain the exact constants when A(R) is the set of convex functions or a suitable set of continuous piecewise linear functions. info:eu-repo/grantAgreement/ES/DGA/E64 info:eu-repo/grantAgreement/ES/MINECO/MTM2015-67006-P info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 0.791 2016 MATHEMATICS 106 / 310 = 0.342 2016 Q2 T2 MATHEMATICS, APPLIED 157 / 255 = 0.616 2016 Q3 T2 0.807 2016 Analysis 2016 Q2 Discrete Mathematics and Combinatorics 2016 Q2 Applied Mathematics 2016 Q2 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion (orcid)0000-0001-6555-4432 Lekuona, A. Universidad de Zaragoza 2007 265 Universidad de Zaragoza Dpto. Métodos Estadísticos Área Estadís. Investig. Opera. 2016, 137 (2016), [17 pp.] J. inequal. appl. JOURNAL OF INEQUALITIES AND APPLICATIONS 1025-5834 1759176 http://zaguan.unizar.es/record/56290/files/texto_completo.pdf Versión publicada 66251 http://zaguan.unizar.es/record/56290/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:56290 articulos driver 2020-02-21-13:10:37 ARTICLE