eprintid: 1751 rev_number: 4 eprint_status: archive userid: 46 dir: disk0/00/00/17/51 datestamp: 2013-09-17 07:44:28 lastmod: 2013-09-17 07:44:28 status_changed: 2013-09-17 07:44:28 type: article succeeds: 1720 metadata_visibility: show creators_name: Gnecco, Giorgio creators_name: Kůrková, Věra creators_name: Sanguineti, Marcello creators_id: giorgio.gnecco@imtlucca.it creators_id: creators_id: title: Can Dictionary-Based Computational Models Outperform the Best Linear Ones? ispublished: pub subjects: QA75 divisions: CSA full_text_status: none keywords: Dictionary-based approximation; Linear approximation; Rates of approximation; Worst-case error; Kolmogorov width; Perceptron networks note: Special Issue "Artificial Neural Networks: Selected Papers from ICANN 2010" abstract: Approximation capabilities of two types of computational models are explored: dictionary-based models (i.e., linear combinations of n -tuples of basis functions computable by units belonging to a set called “dictionary”) and linear ones (i.e., linear combinations of n fixed basis functions). The two models are compared in terms of approximation rates, i.e., speeds of decrease of approximation errors for a growing number n of basis functions. Proofs of upper bounds on approximation rates by dictionary-based models are inspected, to show that for individual functions they do not imply estimates for dictionary-based models that do not hold also for some linear models. Instead, the possibility of getting faster approximation rates by dictionary-based models is demonstrated for worst-case errors in approximation of suitable sets of functions. For such sets, even geometric upper bounds hold. date: 2011 date_type: published publication: Neural Networks volume: 24 number: 8 publisher: Elseviers pagerange: 881 - 887 id_number: 10.1016/j.neunet.2011.05.014 refereed: TRUE issn: 0893-6080 official_url: http://www.sciencedirect.com/science/article/pii/S0893608011001560 citation: Gnecco, Giorgio and Kůrková, Věra and Sanguineti, Marcello Can Dictionary-Based Computational Models Outperform the Best Linear Ones? Neural Networks , 24 (8). 881 - 887. ISSN 0893-6080 (2011)