Search Results for author: Nicolas Tremblay

Found 21 papers, 7 papers with code

Convergence of Message Passing Graph Neural Networks with Generic Aggregation On Large Random Graphs

no code implementations21 Apr 2023 Matthieu Cordonnier, Nicolas Keriven, Nicolas Tremblay, Samuel Vaiter

We study the convergence of message passing graph neural networks on random graph models to their continuous counterpart as the number of nodes tends to infinity.

A Faster Sampler for Discrete Determinantal Point Processes

1 code implementation31 Oct 2022 Simon Barthelmé, Nicolas Tremblay, Pierre-Olivier Amblard

Finally, an interesting by-product of the analysis is that a realisation from a DPP is typically contained in a subset of size O(m log m) formed using leverage score i. i. d.

Point Processes

Variance Reduction for Inverse Trace Estimation via Random Spanning Forests

no code implementations15 Jun 2022 Yusuf Yigit Pilavci, Pierre-Olivier Amblard, Simon Barthelme, Nicolas Tremblay

The trace $\tr(q(\ma{L} + q\ma{I})^{-1})$, where $\ma{L}$ is a symmetric diagonally dominant matrix, is the quantity of interest in some machine learning problems.

Nishimori meets Bethe: a spectral method for node classification in sparse weighted graphs

1 code implementation5 Mar 2021 Lorenzo Dall'Amico, Romain Couillet, Nicolas Tremblay

This article unveils a new relation between the Nishimori temperature parametrizing a distribution P and the Bethe free energy on random Erdos-Renyi graphs with edge weights distributed according to P. Estimating the Nishimori temperature being a task of major importance in Bayesian inference problems, as a practical corollary of this new relation, a numerical method is proposed to accurately estimate the Nishimori temperature from the eigenvalues of the Bethe Hessian matrix of the weighted graph.

Bayesian Inference General Classification +2

Fast Graph Kernel with Optical Random Features

1 code implementation16 Oct 2020 Hashem Ghanem, Nicolas Keriven, Nicolas Tremblay

If this method can still be prohibitively costly for usual random features, we then incorporate optical random features that can be computed in constant time.

Graph Classification

A unified framework for spectral clustering in sparse graphs

1 code implementation20 Mar 2020 Lorenzo Dall'Amico, Romain Couillet, Nicolas Tremblay

This article considers spectral community detection in the regime of sparse networks with heterogeneous degree distributions, for which we devise an algorithm to efficiently retrieve communities.

Clustering Community Detection

Optimal Laplacian regularization for sparse spectral community detection

no code implementations3 Dec 2019 Lorenzo Dall'Amico, Romain Couillet, Nicolas Tremblay

Regularization of the classical Laplacian matrices was empirically shown to improve spectral clustering in sparse networks.

Clustering Community Detection

Approximating Spectral Clustering via Sampling: a Review

no code implementations29 Jan 2019 Nicolas Tremblay, Andreas Loukas

Spectral clustering refers to a family of unsupervised learning algorithms that compute a spectral embedding of the original data based on the eigenvectors of a similarity graph.

Clustering

Determinantal Point Processes for Coresets

2 code implementations23 Mar 2018 Nicolas Tremblay, Simon Barthelmé, Pierre-Olivier Amblard

We apply our results to both the k-means and the linear regression problems, and give extensive empirical evidence that the small additional computational cost of DPP sampling comes with superior performance over its iid counterpart.

Point Processes regression

Asymptotic Equivalence of Fixed-size and Varying-size Determinantal Point Processes

no code implementations5 Mar 2018 Simon Barthelmé, Pierre-Olivier Amblard, Nicolas Tremblay

In this work we show that as the size of the ground set grows, $k$-DPPs and DPPs become equivalent, meaning that their inclusion probabilities converge.

Point Processes

Optimized Algorithms to Sample Determinantal Point Processes

2 code implementations23 Feb 2018 Nicolas Tremblay, Simon Barthelme, Pierre-Olivier Amblard

The standard sampling algorithm is separated in three phases: 1/~eigendecomposition of $\mathbf{L}$, 2/~an eigenvector sampling phase where $\mathbf{L}$'s eigenvectors are sampled independently via a Bernoulli variable parametrized by their associated eigenvalue, 3/~a Gram-Schmidt-type orthogonalisation procedure of the sampled eigenvectors.

Point Processes

Design of graph filters and filterbanks

no code implementations3 Nov 2017 Nicolas Tremblay, Paulo Gonçalves, Pierre Borgnat

The aim of this chapter is to review general concepts for the introduction of filters and representations of graph signals.

Signal Processing Information Theory Social and Information Networks Information Theory

Échantillonnage de signaux sur graphes via des processus déterminantaux

no code implementations7 Apr 2017 Nicolas Tremblay, Simon Barthelme, Pierre-Olivier Amblard

We consider the problem of sampling k-bandlimited graph signals, ie, linear combinations of the first k graph Fourier modes.

Point Processes

Graph sampling with determinantal processes

no code implementations5 Mar 2017 Nicolas Tremblay, Pierre-Olivier Amblard, Simon Barthelmé

For large graphs, ie, in cases where the graph's spectrum is not accessible, we investigate, both theoretically and empirically, a sub-optimal but much faster DPP based on loop-erased random walks on the graph.

Graph Sampling Point Processes

Compressive K-means

no code implementations27 Oct 2016 Nicolas Keriven, Nicolas Tremblay, Yann Traonmilin, Rémi Gribonval

We demonstrate empirically that CKM performs similarly to Lloyd-Max, for a sketch size proportional to the number of cen-troids times the ambient dimension, and independent of the size of the original dataset.

Clustering General Classification

Compressive Spectral Clustering

no code implementations5 Feb 2016 Nicolas Tremblay, Gilles Puy, Remi Gribonval, Pierre Vandergheynst

Spectral clustering has become a popular technique due to its high performance in many contexts.

Clustering

Random sampling of bandlimited signals on graphs

no code implementations16 Nov 2015 Gilles Puy, Nicolas Tremblay, Rémi Gribonval, Pierre Vandergheynst

On the contrary, the second strategy is adaptive but yields optimal results.

Accelerated Spectral Clustering Using Graph Filtering Of Random Signals

no code implementations29 Sep 2015 Nicolas Tremblay, Gilles Puy, Pierre Borgnat, Remi Gribonval, Pierre Vandergheynst

We build upon recent advances in graph signal processing to propose a faster spectral clustering algorithm.

Social and Information Networks Numerical Analysis

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