Quote
B. Lenze, "On constructive one-sided approximation of multivariate functions of bounded variation," Numerical Functional Analysis and Optimization, vol. 11, no. 1-2, pp. 55-83, 1990.
Content
In this paper we present a constructive strategy for one-sided approximation of multivariate functions of bounded variation. The approach is based on a special kind of Lebesgue-Stieltjes convolution operator depending on a hyperbolic argument. We prove local, global, and saturation-type results and, finally, take a look at the applicability of the new operators.
References
DOI 10.1080/01630569008816361