TY - JOUR VL - 57 EP - 558 PB - IEEE SP - 549 A1 - Gnecco, Giorgio A1 - Sanguineti, Marcello AV - none ID - eprints1719 TI - On a Variational Norm Tailored to Variable-Basis Approximation Schemes UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5673958&isnumber=5673678 IS - 1 KW - ${cal L}_1$-norm KW - Approximation schemes KW - convex hulls KW - infinite-dimensional optimization KW - upper and lower bounds KW - variation with respect to a set SN - 0018-9448 Y1 - 2011/// JF - IEEE Transactions on Information Theory N2 - A variational norm associated with sets of computational units and used in function approximation, learning from data, and infinite-dimensional optimization is investigated. For sets Gk obtained by varying a vector y of parameters in a fixed-structure computational unit K(-,y) (e.g., the set of Gaussians with free centers and widths), upper and lower bounds on the GK -variation norms of functions having certain integral representations are given, in terms of the £1-norms of the weighting functions in such representations. Families of functions for which the two norms are equal are described. ER -