eprintid: 3142 rev_number: 12 eprint_status: archive userid: 69 dir: disk0/00/00/31/42 datestamp: 2016-02-26 15:41:35 lastmod: 2016-10-04 09:03:37 status_changed: 2016-10-04 09:03:37 type: monograph metadata_visibility: show creators_name: Gnecco, Giorgio creators_name: Bemporad, Alberto creators_name: Gori, Marco creators_name: Sanguineti, Marcello creators_id: giorgio.gnecco@imtlucca.it creators_id: alberto.bemporad@imtlucca.it creators_id: creators_id: title: Linear Quadratic Gaussian (LQG) online learning ispublished: submitted subjects: QA75 divisions: CSA full_text_status: public monograph_type: working_paper abstract: Optimal control theory and machine learning techniques are combined to propose and solve in closed form an optimal control formulation of online learning from supervised examples. The connections with the classical Linear Quadratic Gaussian (LQG) optimal control problem, of which the proposed learning paradigm is a non trivial variation as it involves random matrices, are investigated. The obtained optimal solutions are compared with the Kalman-filter estimate of the parameter vector to be learned. It is shown that the former enjoys larger smoothness and robustness to outliers, thanks to the presence of a regularization term. The basic formulation of the proposed online-learning framework refers to a discrete time setting with a finite learning horizon and a linear model. Various extensions are investigated, including the infinite learning horizon and, via the so-called "kernel trick", the case of nonlinear models. Subjects: Optimization and Control (math.OC) Cite as: arXiv:1606.04272 [math.OC] (or arXiv:1606.04272v2 [math.OC] for this version) date: 2016 date_type: submitted publisher: arXiv pages: 69 id_number: arXiv:1606.04272 institution: IMT Institute for Advanced Studies Lucca refereed: FALSE official_url: https://arxiv.org/abs/1606.04272 citation: Gnecco, Giorgio and Bemporad, Alberto and Gori, Marco and Sanguineti, Marcello Linear Quadratic Gaussian (LQG) online learning. Working Paper arXiv (Submitted) document_url: http://eprints.imtlucca.it/3142/1/1606.04272v2.pdf