Search Results for author: Faicel Chamroukhi

Found 31 papers, 4 papers with code

Functional mixture-of-experts for classification

no code implementations28 Feb 2022 Nhat Thien Pham, Faicel Chamroukhi

We develop a mixtures-of-experts (ME) approach to the multiclass classification where the predictors are univariate functions.

Classification

Spectral image clustering on dual-energy CT scans using functional regression mixtures

1 code implementation31 Jan 2022 Segolene Brivet, Faicel Chamroukhi, Mark Coates, Reza Forghani, Peter Savadjiev

In this paper, we develop novel functional data analysis (FDA) techniques and adapt them to the analysis of DECT decay curves.

Clustering Image Clustering +1

Non-asymptotic model selection in block-diagonal mixture of polynomial experts models

no code implementations18 Apr 2021 TrungTin Nguyen, Faicel Chamroukhi, Hien Duy Nguyen, Florence Forbes

This model selection criterion allows us to handle the challenging problem of inferring the number of mixture components, the degree of polynomial mean functions, and the hidden block-diagonal structures of the covariance matrices, which reduces the number of parameters to be estimated and leads to a trade-off between complexity and sparsity in the model.

Model Selection regression

A non-asymptotic approach for model selection via penalization in high-dimensional mixture of experts models

1 code implementation6 Apr 2021 TrungTin Nguyen, Hien Duy Nguyen, Faicel Chamroukhi, Florence Forbes

Mixture of experts (MoE) are a popular class of statistical and machine learning models that have gained attention over the years due to their flexibility and efficiency.

Model Selection

Non-asymptotic oracle inequalities for the Lasso in high-dimensional mixture of experts

no code implementations22 Sep 2020 TrungTin Nguyen, Hien D. Nguyen, Faicel Chamroukhi, Geoffrey J. McLachlan

Mixture of experts (MoE) has a well-principled finite mixture model construction for prediction, allowing the gating network (mixture weights) to learn from the predictors (explanatory variables) together with the experts' network (mixture component densities).

feature selection Model Selection +1

Estimation and Feature Selection in Mixtures of Generalized Linear Experts Models

1 code implementation14 Jul 2019 Bao Tuyen Huynh, Faicel Chamroukhi

Mixtures-of-Experts (MoE) are conditional mixture models that have shown their performance in modeling heterogeneity in data in many statistical learning approaches for prediction, including regression and classification, as well as for clustering.

Clustering feature selection +1

Regularized Maximum Likelihood Estimation and Feature Selection in Mixtures-of-Experts Models

no code implementations29 Oct 2018 Faicel Chamroukhi, Bao-Tuyen Huynh

Mixture of Experts (MoE) are successful models for modeling heterogeneous data in many statistical learning problems including regression, clustering and classification.

Clustering feature selection +1

Model-Based Clustering and Classification of Functional Data

no code implementations1 Mar 2018 Faicel Chamroukhi, Hien D. Nguyen

FDA is the data analysis paradigm in which the individual data units are functions (e. g., curves, surfaces), rather than simple vectors.

Classification Clustering +2

An Introduction to the Practical and Theoretical Aspects of Mixture-of-Experts Modeling

no code implementations12 Jul 2017 Hien D. Nguyen, Faicel Chamroukhi

Due to the probabilistic nature of MoE models, we propose the maximum quasi-likelihood (MQL) estimator as a method for estimating MoE model parameters from data, and we provide conditions under which MQL estimators are consistent and asymptotically normal.

Clustering

Robust mixture of experts modeling using the skew $t$ distribution

no code implementations9 Dec 2016 Faicel Chamroukhi

Mixture of Experts (MoE) is a popular framework in the fields of statistics and machine learning for modeling heterogeneity in data for regression, classification and clustering.

Clustering regression

Robust mixture of experts modeling using the $t$ distribution

no code implementations9 Dec 2016 Faicel Chamroukhi

For regression and cluster analyses of continuous data, MoE usually use normal experts following the Gaussian distribution.

Clustering regression

Bayesian mixtures of spatial spline regressions

no code implementations4 Aug 2015 Faicel Chamroukhi

Then, in order to model populations of spatial functional data issued from heterogeneous groups, we integrate the BSSR model into a mixture framework.

Clustering Density Estimation +2

Non-Normal Mixtures of Experts

3 code implementations22 Jun 2015 Faicel Chamroukhi

Mixture of Experts (MoE) is a popular framework for modeling heterogeneity in data for regression, classification and clustering.

Clustering regression

Dirichlet Process Parsimonious Mixtures for clustering

no code implementations14 Jan 2015 Faicel Chamroukhi, Marius Bartcus, Hervé Glotin

The proposed DPPM models are Bayesian nonparametric parsimonious mixture models that allow to simultaneously infer the model parameters, the optimal number of mixture components and the optimal parsimonious mixture structure from the data.

Clustering Model Selection

Unsupervised learning of regression mixture models with unknown number of components

no code implementations24 Sep 2014 Faicel Chamroukhi

The proposed learning approach is fully unsupervised: 1) it simultaneously infers the model parameters and the optimal number of the regression mixture components from the data as the learning proceeds, rather than in a two-fold scheme as in standard model-based clustering using afterward model selection criteria, and 2) it does not require accurate initialization unlike the standard EM for regression mixtures.

Clustering Model Selection +1

A regression model with a hidden logistic process for signal parametrization

no code implementations25 Dec 2013 Faicel Chamroukhi, Allou Samé, Gérard Govaert, Patrice Aknin

A new approach for signal parametrization, which consists of a specific regression model incorporating a discrete hidden logistic process, is proposed.

regression

A regression model with a hidden logistic process for feature extraction from time series

no code implementations25 Dec 2013 Faicel Chamroukhi, Allou Samé, Gérard Govaert, Patrice Aknin

The parameters of the hidden logistic process, in the inner loop of the EM algorithm, are estimated using a multi-class Iterative Reweighted Least-Squares (IRLS) algorithm.

regression Time Series +1

Robust EM algorithm for model-based curve clustering

no code implementations25 Dec 2013 Faicel Chamroukhi

Our approach both handles the problem of initialization and the one of choosing the optimal number of clusters as the EM learning proceeds, rather than in a two-fold scheme.

Clustering Density Estimation +1

Supervised learning of a regression model based on latent process. Application to the estimation of fuel cell life time

no code implementations25 Dec 2013 Raïssa Onanena, Faicel Chamroukhi, Latifa Oukhellou, Denis Candusso, Patrice Aknin, Daniel Hissel

This paper describes a pattern recognition approach aiming to estimate fuel cell duration time from electrochemical impedance spectroscopy measurements.

regression

Mixture model-based functional discriminant analysis for curve classification

no code implementations25 Dec 2013 Faicel Chamroukhi, Hervé Glotin

More specifically, we propose a new mixture model-based discriminant analysis approach for functional data using a specific hidden process regression model.

Classification General Classification +1

Model-based clustering and segmentation of time series with changes in regime

no code implementations25 Dec 2013 Allou Samé, Faicel Chamroukhi, Gérard Govaert, Patrice Aknin

The proposed approach can also be regarded as a clustering approach which operates by finding groups of time series having common changes in regime.

Clustering Time Series +1

Joint segmentation of multivariate time series with hidden process regression for human activity recognition

no code implementations25 Dec 2013 Faicel Chamroukhi, Samer Mohammed, Dorra Trabelsi, Latifa Oukhellou, Yacine Amirat

The problem of human activity recognition is central for understanding and predicting the human behavior, in particular in a prospective of assistive services to humans, such as health monitoring, well being, security, etc.

Human Activity Recognition regression +2

Model-based functional mixture discriminant analysis with hidden process regression for curve classification

no code implementations25 Dec 2013 Faicel Chamroukhi, Hervé Glotin, Allou Samé

We propose a new model-based functional mixture discriminant analysis approach based on a specific hidden process regression model that governs the regime changes over time.

General Classification regression

Model-based clustering with Hidden Markov Model regression for time series with regime changes

no code implementations25 Dec 2013 Faicel Chamroukhi, Allou Samé, Patrice Aknin, Gérard Govaert

Comparisons with existing approaches for time series clustering, including the stand EM for Gaussian mixtures, $K$-means clustering, the standard mixture of regression models and mixture of Hidden Markov Models, demonstrate the effectiveness of the proposed approach.

Clustering regression +2

Functional Mixture Discriminant Analysis with hidden process regression for curve classification

no code implementations25 Dec 2013 Faicel Chamroukhi, Heré Glotin, Céline Rabouy

We present a new mixture model-based discriminant analysis approach for functional data using a specific hidden process regression model.

General Classification regression

Modèle à processus latent et algorithme EM pour la régression non linéaire

no code implementations25 Dec 2013 Faicel Chamroukhi, Allou Samé, Gérard Govaert, Patrice Aknin

A non linear regression approach which consists of a specific regression model incorporating a latent process, allowing various polynomial regression models to be activated preferentially and smoothly, is introduced in this paper.

regression

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