Search Results for author: Yohann de Castro

Found 19 papers, 6 papers with code

FastPart: Over-Parameterized Stochastic Gradient Descent for Sparse optimisation on Measures

no code implementations10 Dec 2023 Yohann de Castro, Sébastien Gadat, Clément Marteau

This paper presents a novel algorithm that leverages Stochastic Gradient Descent strategies in conjunction with Random Features to augment the scalability of Conic Particle Gradient Descent (CPGD) specifically tailored for solving sparse optimisation problems on measures.

Mathematical Proofs

Neural Networks beyond explainability: Selective inference for sequence motifs

no code implementations23 Dec 2022 Antoine Villié, Philippe Veber, Yohann de Castro, Laurent Jacob

Over the past decade, neural networks have been successful at making predictions from biological sequences, especially in the context of regulatory genomics.

Three rates of convergence or separation via U-statistics in a dependent framework

no code implementations24 Jun 2021 Quentin Duchemin, Yohann de Castro, Claire Lacour

Despite the ubiquity of U-statistics in modern Probability and Statistics, their non-asymptotic analysis in a dependent framework may have been overlooked.

Minimax Estimation of Partially-Observed Vector AutoRegressions

1 code implementation17 Jun 2021 Guillaume Dalle, Yohann de Castro

High-dimensional time series are a core ingredient of the statistical modeling toolkit, for which numerous estimation methods are known. But when observations are scarce or corrupted, the learning task becomes much harder. The question is: how much harder?

Time Series Time Series Analysis

Towards Off-the-grid Algorithms for Total Variation Regularized Inverse Problems

1 code implementation14 Apr 2021 Yohann de Castro, Vincent Duval, Romain Petit

We introduce an algorithm to solve linear inverse problems regularized with the total (gradient) variation in a gridless manner.

Forecasting Nonnegative Time Series via Sliding Mask Method (SMM) and Latent Clustered Forecast (LCF)

no code implementations10 Feb 2021 Yohann de Castro, Luca Mencarelli

Based on recent advances in Nonnegative Matrix Factorization (NMF) and Archetypal Analysis, we introduce two procedures referred to as Sliding Mask Method (SMM) and Latent Clustered Forecast (LCF).

Clustering Dimensionality Reduction +3

Concentration inequality for U-statistics of order two for uniformly ergodic Markov chains

1 code implementation20 Nov 2020 Quentin Duchemin, Yohann de Castro, Claire Lacour

We prove a new concentration inequality for U-statistics of order two for uniformly ergodic Markov chains.

Blocking

Dual optimal design and the Christoffel-Darboux polynomial

no code implementations8 Sep 2020 Yohann de Castro, Fabrice Gamboa, Didier Henrion, Jean Lasserre

The purpose of this short note is to show that the Christoffel-Darboux polynomial, useful in approximation theory and data science, arises naturally when deriving the dual to the problem of semi-algebraic D-optimal experimental design in statistics.

Optimization and Control Statistics Theory Statistics Theory

Markov Random Geometric Graph (MRGG): A Growth Model for Temporal Dynamic Networks

no code implementations12 Jun 2020 Quentin Duchemin, Yohann de Castro

It is based on a Markovian latent space dynamic: consecutive latent points are sampled on the Euclidean Sphere using an unknown Markov kernel; and two nodes are connected with a probability depending on a unknown function of their latent geodesic distance.

Clustering Link Prediction

Latent Distance Estimation for Random Geometric Graphs

1 code implementation NeurIPS 2019 Ernesto Araya, Yohann de Castro

We introduce a spectral estimator of the pairwise distance between latent points and we prove that its rate of convergence is the same as the nonparametric estimation of a function on $\mathbb{S}^{d-1}$, up to a logarithmic factor.

SuperMix: Sparse Regularization for Mixtures

no code implementations23 Jul 2019 Yohann de Castro, Sébastien Gadat, Clément Marteau, Cathy Maugis

This paper investigates the statistical estimation of a discrete mixing measure $\mu$0 involved in a kernel mixture model.

Nonnegative matrix factorization with side information for time series recovery and prediction

no code implementations19 Sep 2017 Jiali Mei, Yohann de Castro, Yannig Goude, Jean-Marc Azaïs, Georges Hébrail

Motivated by the reconstruction and the prediction of electricity consumption, we extend Nonnegative Matrix Factorization~(NMF) to take into account side information (column or row features).

Time Series Time Series Analysis

Nonnegative Matrix Factorization for Time Series Recovery From a Few Temporal Aggregates

no code implementations ICML 2017 Jiali Mei, Yohann de Castro, Yannig Goude, Georges Hébrail

Motivated by electricity consumption reconstitution, we propose a new matrix recovery method using nonnegative matrix factorization (NMF).

Time Series Time Series Analysis

Approximate Optimal Designs for Multivariate Polynomial Regression

1 code implementation9 Jun 2017 Yohann De Castro, Fabrice Gamboa, Didier Henrion, Roxana Hess, Jean-Bernard Lasserre

We introduce a new approach aiming at computing approximate optimal designs for multivariate polynomial regressions on compact (semi-algebraic) design spaces.

Statistics Theory Information Theory Information Theory Numerical Analysis Computation Methodology Statistics Theory 62K05, 90C25 (Primary) 41A10, 49M29, 90C90, 15A15 (secondary)

Testing Gaussian Process with Applications to Super-Resolution

1 code implementation2 Jun 2017 Jean-Marc Azaïs, Yohann de Castro, Stéphane Mourareau

This article introduces exact testing procedures on the mean of a Gaussian process $X$ derived from the outcomes of $\ell_1$-minimization over the space of complex valued measures.

Statistics Theory Information Theory Information Theory Probability Statistics Theory 62E15, 62F03, 60G15, 62H10, 62H15 (Primary) 60E05, 60G10, 62J05, 94A08 (secondary)

Recovering Multiple Nonnegative Time Series From a Few Temporal Aggregates

no code implementations5 Oct 2016 Jiali Mei, Yohann de Castro, Yannig Goude, Georges Hébrail

Motivated by electricity consumption metering, we extend existing nonnegative matrix factorization (NMF) algorithms to use linear measurements as observations, instead of matrix entries.

Time Series Time Series Analysis

Sparse Recovery from Extreme Eigenvalues Deviation Inequalities

no code implementations5 Apr 2016 Sandrine Dallaporta, Yohann de Castro

One benefit of this paper is a direct and explicit derivation of upper bounds on RICs and lower bounds on SRSR from small deviations on the extreme eigenvalues given by Random Matrix theory.

Reconstructing undirected graphs from eigenspaces

no code implementations26 Mar 2016 Yohann De Castro, Thibault Espinasse, Paul Rochet

In this paper, we aim at recovering an undirected weighted graph of $N$ vertices from the knowledge of a perturbed version of the eigenspaces of its adjacency matrix $W$.

Optimal designs for Lasso and Dantzig selector using Expander Codes

no code implementations12 Oct 2010 Yohann de Castro

We investigate the high-dimensional regression problem using adjacency matrices of unbalanced expander graphs.

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