Search Results for author: Silvia Villa

Found 13 papers, 1 papers with code

Variance reduction techniques for stochastic proximal point algorithms

no code implementations18 Aug 2023 Cheik Traoré, Vassilis Apidopoulos, Saverio Salzo, Silvia Villa

Stochastic proximal point algorithms have been studied as an alternative to stochastic gradient algorithms since they are more stable with respect to the choice of the stepsize but a proper variance reduced version is missing.

Snacks: a fast large-scale kernel SVM solver

no code implementations17 Apr 2023 Sofiane Tanji, Andrea Della Vecchia, François Glineur, Silvia Villa

Kernel methods provide a powerful framework for non parametric learning.

Stochastic Zeroth order Descent with Structured Directions

no code implementations10 Jun 2022 Marco Rando, Cesare Molinari, Silvia Villa, Lorenzo Rosasco

For smooth convex functions we prove almost sure convergence of the iterates and a convergence rate on the function values of the form $O(d/l k^{-c})$ for every $c<1/2$, which is arbitrarily close to the one of Stochastic Gradient Descent (SGD) in terms of number of iterations.

Iterative regularization for low complexity regularizers

no code implementations1 Feb 2022 Cesare Molinari, Mathurin Massias, Lorenzo Rosasco, Silvia Villa

Our approach is based on a primal-dual algorithm of which we analyze convergence and stability properties, even in the case where the original problem is unfeasible.

Ada-BKB: Scalable Gaussian Process Optimization on Continuous Domains by Adaptive Discretization

no code implementations16 Jun 2021 Marco Rando, Luigi Carratino, Silvia Villa, Lorenzo Rosasco

In this paper, we introduce Ada-BKB (Adaptive Budgeted Kernelized Bandit), a no-regret Gaussian process optimization algorithm for functions on continuous domains, that provably runs in $O(T^2 d_\text{eff}^2)$, where $d_\text{eff}$ is the effective dimension of the explored space, and which is typically much smaller than $T$.

Iterative regularization for convex regularizers

1 code implementation17 Jun 2020 Cesare Molinari, Mathurin Massias, Lorenzo Rosasco, Silvia Villa

We study iterative regularization for linear models, when the bias is convex but not necessarily strongly convex.

Don't relax: early stopping for convex regularization

no code implementations18 Jul 2017 Simon Matet, Lorenzo Rosasco, Silvia Villa, Bang Long Vu

We consider the problem of designing efficient regularization algorithms when regularization is encoded by a (strongly) convex functional.

Convergence of the Forward-Backward Algorithm: Beyond the Worst Case with the Help of Geometry

no code implementations28 Mar 2017 Guillaume Garrigos, Lorenzo Rosasco, Silvia Villa

We provide a comprehensive study of the convergence of the forward-backward algorithm under suitable geometric conditions, such as conditioning or {\L}ojasiewicz properties.

Learning Multiple Visual Tasks while Discovering their Structure

no code implementations CVPR 2015 Carlo Ciliberto, Lorenzo Rosasco, Silvia Villa

Multi-task learning is a natural approach for computer vision applications that require the simultaneous solution of several distinct but related problems, e. g. object detection, classification, tracking of multiple agents, or denoising, to name a few.

Denoising General Classification +3

Learning with incremental iterative regularization

no code implementations NeurIPS 2015 Lorenzo Rosasco, Silvia Villa

Within a statistical learning setting, we propose and study an iterative regularization algorithm for least squares defined by an incremental gradient method.

BIG-bench Machine Learning

On Learnability, Complexity and Stability

no code implementations24 Mar 2013 Silvia Villa, Lorenzo Rosasco, Tomaso Poggio

We consider the fundamental question of learnability of a hypotheses class in the supervised learning setting and in the general learning setting introduced by Vladimir Vapnik.

A Primal-Dual Algorithm for Group Sparse Regularization with Overlapping Groups

no code implementations NeurIPS 2010 Sofia Mosci, Silvia Villa, Alessandro Verri, Lorenzo Rosasco

We deal with the problem of variable selection when variables must be selected group-wise, with possibly overlapping groups defined a priori.

Variable Selection

Cannot find the paper you are looking for? You can Submit a new open access paper.