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Record Number10266
Reference TypeConference Proceedings
Author(s)Ting, J.;Kalakrishnan, M.;Vijayakumar, S.;Schaal, S.
Year2008
TitleBayesian kernel shaping for learning control
Journal/Conference/Book TitleAdvances in Neural Information Processing Systems 21 (NIPS 2008)
Keywordslocally weighted learning, kernel regression, bayesian learning, nonstationary processes

Abstract

In kernel-based regression learning, optimizing each kernel individually is useful when the data density, curvature of regression surfaces (or decision boundaries) or magnitude of output noise varies spatially. Previous work has suggested gradi- ent descent techniques or complex statistical hypothesis methods for local kernel shaping, typically requiring some amount of manual tuning of meta parameters. We introduce a Bayesian formulation of nonparametric regression that, with the help of variational approximations, results in an EM-like algorithm for simulta- neous estimation of regression and kernel parameters. The algorithm is computa- tionally efficient, requires no sampling, automatically rejects outliers and has only one prior to be specified. It can be used for nonparametric regression with local polynomials or as a novel method to achieve nonstationary regression with Gaus- sian processes. Our methods are particularly useful for learning control, where reliable estimation of local tangent planes is essential for adaptive controllers and reinforcement learning. We evaluate our methods on several synthetic data sets and on an actual robot which learns a task-level control law.
Notesclmc
URL(s) http://www-clmc.usc.edu/publications/T/ting-NIPS2008.pdf
Editor(s)Koller, D.;Bengio, Y.;Schuurmans, D.;Bottou, L.;Culotta, A.
Place PublishedVancouver, BC, Dec. 7-10
PublisherCambridge, MA: MIT Press
Short TitleBayesian kernel shaping for learning control

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