Statistics Seminar Speaker Michael Chichignoud, 3/12/14 @ 4:15 pm

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Wednesday Mar 12 2014

Statistics Seminar Speaker Michael Chichignoud, 3/12/14 @ 4:15 pm

4:15pm @ G01 Biotech

This week's Statistics Seminar Speaker will be Michael Chichignoud from ETH Zurich.

Title:  On Bandwidth Selection in Empirical Risk Minimization

Abstract:  I will first start by a short summary on bandwidth selection methods such as Cross-Validation or Lepski-type procedure explaining their strengths and weaknesses.  Our contributions joined with J. Lederer and S. Loustau consist of a data-driven selection of the bandwidth for empirical risk minimization.  One typically deals with this issue in pointwise estimation in the setting of heavy-tail noises with local M-estimators. To this end, we apply Lepski's method to these estimators to get optimal (minimax) results in pointwise estimation. Besides, we will explain how we can choose the robustness of M-estimators. In learning theory, many authors have recently investigated supervised and unsupervised learning with errors in variables.  As a rule, such issues (viewed as an inverse problem) require to plug-in deconvolution kernels in the empirical risk (and then select a bandwidth) such as Hall and Lahiri [2008] in quantile and moment estimation, Loustau and Marteau [2013] in noisy discriminant analysis, Loustau [2013] in noisy learning, Chichignoud and Loustau [2013] in noisy clustering and Dattner, Reiß and Trabs [2013] in quantile estimation.  We will especially present the result of Chichignoud and Loustau [2013] in noisy clustering where a new version of Lepski's method is provided to obtain excess risk bounds.

Refreshments will be served after the seminar in 1181 Comstock Hall.