Authors:B. Della Vecchia, G. Mastroianni, and J. Szabados
We prove that the weighted error of approximation by the Szász-Mirakyan-type operator introduced in  is equivalent to the
modulus of smoothness of the function. This result is analogous to previous results for Bernstein-type operators obtained
by Ditzian-Ivanov and Szabados.
Authors:B. Della Vecchia, G. Mastroianni, and P. Vértesi
The authors establish necessary and sufficient conditions for the weightedLp convergence at given rates of Hermite interpolation of higher order based on Jacobi zeros plus the endpoints ±1. Theorems on simultaneous approximation are also proved.