133 results on '"Aknin, Patrice"'
Search Results
2. Model-based clustering with Hidden Markov Model regression for time series with regime changes
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Chamroukhi, Faicel, Samé, Allou, Aknin, Patrice, and Govaert, Gérard
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Statistics - Machine Learning ,Computer Science - Learning ,Statistics - Methodology - Abstract
This paper introduces a novel model-based clustering approach for clustering time series which present changes in regime. It consists of a mixture of polynomial regressions governed by hidden Markov chains. The underlying hidden process for each cluster activates successively several polynomial regimes during time. The parameter estimation is performed by the maximum likelihood method through a dedicated Expectation-Maximization (EM) algorithm. The proposed approach is evaluated using simulated time series and real-world time series issued from a railway diagnosis application. 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., Comment: In Proceedings of the 2011 International Joint Conference on Neural Networks (IJCNN), 2011, Pages 2814 - 2821, San Jose, California
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- 2013
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3. Supervised learning of a regression model based on latent process. Application to the estimation of fuel cell life time
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Onanena, Raïssa, Chamroukhi, Faicel, Oukhellou, Latifa, Candusso, Denis, Aknin, Patrice, and Hissel, Daniel
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Statistics - Machine Learning ,Computer Science - Learning ,Statistics - Applications - Abstract
This paper describes a pattern recognition approach aiming to estimate fuel cell duration time from electrochemical impedance spectroscopy measurements. It consists in first extracting features from both real and imaginary parts of the impedance spectrum. A parametric model is considered in the case of the real part, whereas regression model with latent variables is used in the latter case. Then, a linear regression model using different subsets of extracted features is used fo r the estimation of fuel cell time duration. The performances of the proposed approach are evaluated on experimental data set to show its feasibility. This could lead to interesting perspectives for predictive maintenance policy of fuel cell., Comment: In Proceeding of the 8th IEEE International Conference on Machine Learning and Applications (IEEE ICMLA'09), pages 632-637, 2009, Miami Beach, FL, USA
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- 2013
4. Classification automatique de donn\'ees temporelles en classes ordonn\'ees
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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Statistics - Machine Learning ,Statistics - Methodology - Abstract
This paper proposes a method of segmenting temporal data into ordered classes. It is based on mixture models and a discrete latent process, which enables to successively activates the classes. The classification can be performed by maximizing the likelihood via the EM algorithm or by simultaneously optimizing the model parameters and the partition by the CEM algorithm. These two algorithms can be seen as alternatives to Fisher's algorithm, which improve its computing time., Comment: in French, 44\`emes Journ\'ees de Statistique, SFdS
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- 2013
5. A regression model with a hidden logistic process for feature extraction from time series
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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Statistics - Methodology ,Computer Science - Learning ,Mathematics - Statistics Theory ,Statistics - Machine Learning - Abstract
A new approach for feature extraction from time series is proposed in this paper. This approach consists of a specific regression model incorporating a discrete hidden logistic process. The model parameters are estimated by the maximum likelihood method performed by a dedicated Expectation Maximization (EM) algorithm. 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. A piecewise regression algorithm and its iterative variant have also been considered for comparisons. An experimental study using simulated and real data reveals good performances of the proposed approach., Comment: In Proceedings of the International Joint Conference on Neural Networks (IJCNN), 2009, Atlanta, USA
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- 2013
6. A regression model with a hidden logistic process for signal parametrization
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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Statistics - Methodology ,Computer Science - Learning ,Statistics - Machine Learning - Abstract
A new approach for signal parametrization, which consists of a specific regression model incorporating a discrete hidden logistic process, is proposed. The model parameters are estimated by the maximum likelihood method performed by a dedicated Expectation Maximization (EM) algorithm. 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. An experimental study using simulated and real data reveals good performances of the proposed approach., Comment: In Proceedings of the XVIIth European Symposium on Artificial Neural Networks, Computational Intelligence and Machine Learning (ESANN), Pages 503-508, 2009, Bruges, Belgium
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- 2013
7. A hidden process regression model for functional data description. Application to curve discrimination
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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Statistics - Methodology ,Computer Science - Learning ,Statistics - Machine Learning - Abstract
A new approach for functional data description is proposed in this paper. It consists of a regression model with a discrete hidden logistic process which is adapted for modeling curves with abrupt or smooth regime changes. The model parameters are estimated in a maximum likelihood framework through a dedicated Expectation Maximization (EM) algorithm. From the proposed generative model, a curve discrimination rule is derived using the Maximum A Posteriori rule. The proposed model is evaluated using simulated curves and real world curves acquired during railway switch operations, by performing comparisons with the piecewise regression approach in terms of curve modeling and classification.
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- 2013
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8. Mod\`ele \`a processus latent et algorithme EM pour la r\'egression non lin\'eaire
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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Mathematics - Statistics Theory ,Computer Science - Learning ,Statistics - Methodology ,Statistics - Machine Learning - Abstract
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. The model parameters are estimated by maximum likelihood performed via a dedicated expecation-maximization (EM) algorithm. An experimental study using simulated and real data sets reveals good performances of the proposed approach.
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- 2013
9. Time series modeling by a regression approach based on a latent process
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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Statistics - Methodology ,Computer Science - Learning ,Mathematics - Statistics Theory ,Statistics - Machine Learning - Abstract
Time series are used in many domains including finance, engineering, economics and bioinformatics generally to represent the change of a measurement over time. Modeling techniques may then be used to give a synthetic representation of such data. A new approach for time series modeling is proposed in this paper. It consists of a regression model incorporating a discrete hidden logistic process allowing for activating smoothly or abruptly different polynomial regression models. The model parameters are estimated by the maximum likelihood method performed by a dedicated Expectation Maximization (EM) algorithm. The M step of the EM algorithm uses a multi-class Iterative Reweighted Least-Squares (IRLS) algorithm to estimate the hidden process parameters. To evaluate the proposed approach, an experimental study on simulated data and real world data was performed using two alternative approaches: a heteroskedastic piecewise regression model using a global optimization algorithm based on dynamic programming, and a Hidden Markov Regression Model whose parameters are estimated by the Baum-Welch algorithm. Finally, in the context of the remote monitoring of components of the French railway infrastructure, and more particularly the switch mechanism, the proposed approach has been applied to modeling and classifying time series representing the condition measurements acquired during switch operations.
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- 2013
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10. Model-based clustering and segmentation of time series with changes in regime
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Samé, Allou, Chamroukhi, Faicel, Govaert, Gérard, and Aknin, Patrice
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Statistics - Methodology ,Computer Science - Learning ,Mathematics - Statistics Theory ,Statistics - Machine Learning - Abstract
Mixture model-based clustering, usually applied to multidimensional data, has become a popular approach in many data analysis problems, both for its good statistical properties and for the simplicity of implementation of the Expectation-Maximization (EM) algorithm. Within the context of a railway application, this paper introduces a novel mixture model for dealing with time series that are subject to changes in regime. The proposed approach consists in modeling each cluster by a regression model in which the polynomial coefficients vary according to a discrete hidden process. In particular, this approach makes use of logistic functions to model the (smooth or abrupt) transitions between regimes. The model parameters are estimated by the maximum likelihood method solved by an Expectation-Maximization algorithm. The proposed approach can also be regarded as a clustering approach which operates by finding groups of time series having common changes in regime. In addition to providing a time series partition, it therefore provides a time series segmentation. The problem of selecting the optimal numbers of clusters and segments is solved by means of the Bayesian Information Criterion (BIC). The proposed approach is shown to be efficient using a variety of simulated time series and real-world time series of electrical power consumption from rail switching operations.
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- 2013
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11. A variational Expectation–Maximization algorithm for temporal data clustering
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El Assaad, Hani, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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- 2016
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12. Confiance.ai Days 2022. Booklet of articles & posters
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Aknin, Patrice, Braunschweig, Bertrand, Cantat, Loic, Chamroukhi, Faïcel, Hebrail, Georges, Jurie, Frédéric, Loesch, Angelique, Mattioli, Juliette, Oller, Guillaume, IRT SystemX, Equipe Image - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), SAFRAN Group, Département Intelligence Ambiante et Systèmes Interactifs (DIASI), Laboratoire d'Intégration des Systèmes et des Technologies (LIST (CEA)), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, THALES [France], and IRT Saint Exupéry - Institut de Recherche Technologique
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ODD ,[STAT.ML]Statistics [stat]/Machine Learning [stat.ML] ,trustworthy ,AI-based systems ,V&V ,[INFO]Computer Science [cs] ,Robust AI ,Explainability ,Embedded AI ,critical systems - Abstract
Conférence: Confiance.ai Days, 4 au 6 octobre 2022, CentraleSupélec, Gif-sur-Yvette (France); This booklet gathers 52 papers, either in the form of articles or posters, presented during the secondedition of the Confiance.ai Days held in Saclay on October 4-6, 2022. Altogether they give a good snapshotof the research and development work done in the Confiance.ai program, an industrial and academicinitiative of the national Grand Challenge on provable and certifiable AI, launched in support of the France2030 strategy.Among these papers, a dozen are presented as « external contributions » that were selected by an ad-hoccommittee following a call for papers. All other communications belonged to one of five so-called « villages» with physical implementation in the conference hall, distributing the work done in Confiance.ai intofive topics : « End-to-end approach » ; « from Operational Design Domain to Data » ; « Explainabilityand Understanding» ; « Robustness and Monitoring » ; « Embedded AI ».After two years of activity, and complementing the Confiance.ai white paper, this document shows thediversity and the quality of the work done in the programme. Some important and up-to-date subjects areaddressed, such as – only to name a few - out-of-distribution detection, adversarial robustness, semi- orself-supervised learning, explainability by design, verification and validation, embedded AI etc. We hopethat you will enjoy reading parts of this document as much as we enjoyed preparing and attending the 2022Confiance AI days.
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- 2023
13. Dynamic bayesian networks for reliability analysis: from a Markovian point of view to semi-markovian approaches
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Foulliaron, Josquin, Bouillaut, Laurent, Barros, Anne, and Aknin, Patrice
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- 2015
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14. Model-Based Clustering of Temporal Data
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El Assaad, Hani, Samé, Allou, Govaert, Gérard, Aknin, Patrice, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Mladenov, Valeri, editor, Koprinkova-Hristova, Petia, editor, Palm, Günther, editor, Villa, Alessandro E. P., editor, Appollini, Bruno, editor, and Kasabov, Nikola, editor
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- 2013
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15. Mining Floating Train Data Sequences for Temporal Association Rules within a Predictive Maintenance Framework
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Sammouri, Wissam, Côme, Etienne, Oukhellou, Latifa, Aknin, Patrice, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Doug, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Goebel, Randy, editor, Siekmann, Jörg, editor, Wahlster, Wolfgang, editor, and Perner, Petra, editor
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- 2013
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16. Using Imprecise and Uncertain Information to Enhance the Diagnosis of a Railway Device
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Cherfi, Zohra L., Oukhellou, Latifa, Côme, Etienne, Denœux, Thierry, Aknin, Patrice, Kacprzyk, Janusz, editor, Li, Shoumei, editor, Wang, Xia, editor, Okazaki, Yoshiaki, editor, Kawabe, Jun, editor, Murofushi, Toshiaki, editor, and Guan, Li, editor
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- 2011
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17. Noiseless Independent Factor Analysis with Mixing Constraints in a Semi-supervised Framework. Application to Railway Device Fault Diagnosis
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Côme, Etienne, Oukhellou, Latifa, Denœux, Thierry, Aknin, Patrice, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Nierstrasz, Oscar, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Sudan, Madhu, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Vardi, Moshe Y., Series editor, Weikum, Gerhard, Series editor, Alippi, Cesare, editor, Polycarpou, Marios, editor, Panayiotou, Christos, editor, and Ellinas, Georgios, editor
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- 2009
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18. Mixture Model Estimation with Soft Labels
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Côme, Etienne, Oukhellou, Latifa, Denœux, Thierry, Aknin, Patrice, Kacprzyk, J., editor, Dubois, Didier, editor, Lubiano, M. Asunción, editor, Prade, Henri, editor, Gil, María Ángeles, editor, Grzegorzewski, Przemysław, editor, and Hryniewicz, Olgierd, editor
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- 2008
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19. Ho–Kashyap with Early Stopping Versus Soft Margin SVM for Linear Classifiers –An Application
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Lauer, Fabien, Bentoumi, Mohamed, Bloch, Gérard, Millerioux, Gilles, Aknin, Patrice, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Yin, Fu-Liang, editor, Wang, Jun, editor, and Guo, Chengan, editor
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- 2004
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20. A hidden process regression model for functional data description. Application to curve discrimination
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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- 2010
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21. A dynamic Bayesian network to represent discrete duration models
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Donat, Roland, Leray, Philippe, Bouillaut, Laurent, and Aknin, Patrice
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- 2010
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22. Time series modeling by a regression approach based on a latent process
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
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- 2009
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23. Fault diagnosis of a railway device using semi-supervised independent factor analysis with mixing constraints
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Côme, Etienne, Oukhellou, Latifa, Denœux, Thierry, and Aknin, Patrice
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- 2012
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24. Partially supervised Independent Factor Analysis using soft labels elicited from multiple experts: application to railway track circuit diagnosis
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Cherfi, Zohra L., Oukhellou, Latifa, Côme, Etienne, Denœux, Thierry, and Aknin, Patrice
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- 2012
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25. Model-based clustering and segmentation of time series with changes in regime
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Samé, Allou, Chamroukhi, Faicel, Govaert, Gérard, and Aknin, Patrice
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- 2011
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26. Mixture-model-based signal denoising
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Samé, Allou, Oukhellou, Latifa, Côme, Etienne, and Aknin, Patrice
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- 2007
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27. Mining Floating Train Data Sequences for Temporal Association Rules within a Predictive Maintenance Framework
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Sammouri, Wissam, primary, Côme, Etienne, additional, Oukhellou, Latifa, additional, and Aknin, Patrice, additional
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- 2013
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28. Model-Based Clustering of Temporal Data
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El Assaad, Hani, primary, Samé, Allou, additional, Govaert, Gérard, additional, and Aknin, Patrice, additional
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- 2013
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29. Noiseless Independent Factor Analysis with Mixing Constraints in a Semi-supervised Framework. Application to Railway Device Fault Diagnosis
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Côme, Etienne, primary, Oukhellou, Latifa, additional, Denœux, Thierry, additional, and Aknin, Patrice, additional
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- 2009
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30. Ho–Kashyap with Early Stopping Versus Soft Margin SVM for Linear Classifiers –An Application
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Lauer, Fabien, primary, Bentoumi, Mohamed, additional, Bloch, Gérard, additional, Millerioux, Gilles, additional, and Aknin, Patrice, additional
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- 2004
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31. Modèle LSTM encodeur-prédicteur pour la prévision court-terme de l'affluence dans les transports collectifs
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Pasini, Kevin, Khouadjia, Mostepha, Same, Allou, Ganansia, Fabrice, Aknin, Patrice, Oukhellou, Latifa, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, IRT SystemX (IRT SystemX), SNCF : Innovation & Recherche, SNCF, and Cadic, Ifsttar
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MOBILITE ,PREVISION ,[STAT.ML]Statistics [stat]/Machine Learning [stat.ML] ,SERIE TEMPORELLE ,LSTM ,[STAT.ML] Statistics [stat]/Machine Learning [stat.ML] ,MOBILITE URBAINE - Abstract
CAP 2019, Conférence sur l'Apprentissage Automatique, Toulouse, France, 03-/07/2019 - 05/07/2019; Les possibilités offertes en termes de collecte et de stockage de données permettent de renouveler les approches de modélisation dans le domaine du transport. L'exploitation croisée de différentes sources de données a pour vocation la création de services à forte valeur ajoutée pour l'usager. Les travaux détaillées dans cet article portent sur le développement de modèles de prévision a base de méthodes d'apprentissage notamment profond, pour la prévision court-terme de la charge (nombre de passagers) des trains. Cette prévision de l'affluence dans les trains peut servir à enrichir l'information voyageur à destination des usagers des transports collectifs qui peuvent ainsi mieux planifier leur déplacement. Elle peut également servir aux opérateurs de transport pour une régulation "à la demande" de l'offre de transport. La principale difficulté dans la prévision est liée à la variabilité intrinsèque des séries temporelles des charges à prédire, induite par l'influence de plusieurs paramètres dont ceux liés à l'exploitation (horaire, retard, type de mission...) et au contexte (information calendaire, grand évènement, météo,...). Nous proposons un modèle LSTM encodeur-prédicteur pour résoudre cette tâche de prévision. Plusieurs expérimentations sont menées sur des données réelles du réseau Transilien de la SNCF sur une durée d'un an et demi. Les résultats de prévision sont détaillées en vue de comparer les performances d'un tel modèle à plusieurs horizons temporels avec celles d'autres modèles plus classiques utilisées en prévision.
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- 2019
32. DESIGNING THE MISSING LINK BETWEEN SCIENCE AND INDUSTRY: ORGANIZING PARTNERSHIP BASED ON DUAL GENERATIVITY
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Chen, Milena, Aknin, Patrice, Lagadec, Lilly-Rose, Laousse, Dominique, Masson, Pascal, Weil, Benoit, IRT SystemX (IRT SystemX), Innovation & Research, SNCF, Centre de Gestion Scientifique i3 (CGS i3), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-MINES ParisTech - École nationale supérieure des mines de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)
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[SHS.GESTION]Humanities and Social Sciences/Business administration - Abstract
International audience; Industry-academic research partnerships are mostly considered interesting to increase industrial innovativeness, and its benefits have been discussed in the flourishing open innovation literature. However, how to create mutually beneficial partnerships seems to be a question that has not been sufficiently studied. Through this article, we discuss the goals of these partnerships by modelling different types of collaboration. We defend that their real value has to be evaluated not only by looking at the knowledge created, but also at the increase of generativity we observe, due to interactions between academia and industry. Furthermore, we propose a model based on C-K theory that can be used to design a research collaboration that increases generativity, going beyond problem solving and knowledge transfer logics. We illustrate it through a case study, which shows that value creation in an industry-research partnership is increased by a model of co-generation, instead of considering these relations as a one-way transfer. Furthermore, we show that conflicts in a partnership can be solved through a C-K based tool.
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- 2017
33. L’ouverture des données, une opportunité pour la recherche sur les transports et la mobilité
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Aknin, Patrice, primary, Côme, Étienne, additional, and Oukhellou, Latifa, additional
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- 2018
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34. A dynamic Bayesian network approach for prognosis computations on discrete state systems
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Foulliaron, Josquin, primary, Bouillaut, Laurent, additional, Aknin, Patrice, additional, and Barros, Anne, additional
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- 2017
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35. A specific semi-markovian dynamic bayesian network estimating residual useful life
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FOULLIARON, Josquin, Bouillaut, Laurent, Aknin, Patrice, Barros, Anne, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, SNCF : Innovation & Recherche, SNCF, Department of Computer and Information Science [Trondheim] (IDI), Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU), and ANR - Diadem
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MODELE MATHEMATIQUE ,MODELE GRAPHIQUE PROBABILISTE ,DUREE DE VIE ,FIABILITE ,GRAPHICAL DURATION MODEL ,RESIDUAL USEFUL LIFE ESTIMATION ,DYNAMIC BAYESIAN NETWORK ,RESEAU BAYESIEN ,SEMI MARKOVIAN DEGRADATION PROCESS MODELLING ,CYCLE DE VIE ,[INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation - Abstract
16th ASMDA Conference, LE PIREE, GRECE, 30-/06/2015 - 04/07/2015; Degradation processes modelling is a key problem to perform any type of reliability study. Indeed, the quality of the computed reliability indicators and prognosis estimations directly depends on this modelling. Mathematical models commonly used in reliability (Markov chains, Gamma processes...) are based on some assumptions that can lead to a loss of information on the degradation dynamic. In many studies, Dynamic Bayesian Networks (DBN) have been proved relevant to represent multicomponent complex systems and to perform reliability studies. In a previous paper, we introduced a, degradation model based on DBN named graphical duration model (GDM) in order to represent a wide range of duration models. This paper will introduce a new degradation model based on GDM integrating the concept of conditional sojourn time distributions in order to improve the degradation modelling. It integrates the possibility to take into account several degradation modes together and to adapt the degradation modelling in respect of some new available observations of either the current operation state or the estimated degradation level, to take into account an eventual dynamic change. A comparative study on simulated data between the presented model and the GDM will be performed to show the interest of this new approach.
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- 2015
36. Spatio-temporal Analysis of Dynamic Origin-Destination Data Using Latent Dirichlet Allocation: Application to Vélib' Bike Sharing System of Paris
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COME, Etienne, RANDRIAMANAMIHAGA, Njato Andry, Oukhellou, Latifa, Aknin, Patrice, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, and Cadic, Ifsttar
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[SHS.STAT]Humanities and Social Sciences/Methods and statistics ,[SHS.STAT] Humanities and Social Sciences/Methods and statistics ,BASE DE DONNEES - Abstract
This paper deals with a data mining approach applied on Bike Sharing System Origin-Destination data, but part of the proposed methodology can be used to analyze other modes of transport that similarly generate Dynamic Origin-Destination (OD) matrices. The transportation network investigated in this paper is the Vélib’ Bike Sharing System (BSS) system deployed in Paris since 2007. An approach based on Latent Dirichlet Allocation (LDA), that extracts the main features of the spatio-temporal behavior of the BSS is introduced in this paper. Such approach aims to summarize the behavior of the system by extracting few OD-templates, interpreted as typical and temporally localized demand profiles. The spatial analysis of the obtained templates can be used to give insights into the system behavior and the underlying urban phenomena linked to city dynamics.
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- 2014
37. How to keep optimal maintenance strategies with a dynamic optimization approach?
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ROZAS, Rony, Bouillaut, Laurent, Aknin, Patrice, BRANGER, Guillaume, Cadic, Ifsttar, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, and Bombardier Transportation
- Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other ,MAINTENANCE ,OPTIMUM ,[SPI.OTHER] Engineering Sciences [physics]/Other ,OPTIMISATION ,DEGRADATION ,MATERIEL ROULANT ,ENTRETIEN - Abstract
The optimization of maintenance strategies has become a key issue in the railway industry but also in most industrial fields. To address this challenge, many studies dealt with the estimation of optimal maintenance parameters. But what commonly happens when the degradation process suddenly changes? The operator has to face an unexpected, increasing number of severe defects (and then a strong drop of its availability). These changes are generally due to either: a new component, introduced in the system for obsolescence reasons; or changing operating conditions. Based on the dynamic Bayesian networks (DBN), formalism that has been proved relevant to perform reliability analysis can easily represent complex system behaviors. This paper introduces a dynamic maintenance strategy, able to detect these drifts and to evaluate their impacts on the rolling stock doors system’s behavior.
- Published
- 2014
38. Mod\'ele \'a processus latent et algorithme EM pour la r\'egression non lin\'eaire
- Author
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Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, and Aknin, Patrice
- Subjects
Statistics::Machine Learning ,Computer Science - Learning ,Statistics - Machine Learning ,Statistics::Methodology ,Mathematics - Statistics Theory ,Statistics - Methodology - Abstract
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. The model parameters are estimated by maximum likelihood performed via a dedicated expecation-maximization (EM) algorithm. An experimental study using simulated and real data sets reveals good performances of the proposed approach.
- Published
- 2013
39. A rollingstock door system’s dynamic maintenance strategies based on a sensitivity analysis through bayesian networks
- Author
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Rozas, Rony, Bouillaut, Laurent, Aknin, Patrice, Same, Allou, Francois, Olivier, Branger, Guillaume, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Bombardier Transportation, and Cadic, Ifsttar
- Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other ,MAINTENANCE ,[SPI.OTHER] Engineering Sciences [physics]/Other - Abstract
In most industrial fields, and particularly in the railway industry, the optimization of maintenance policies has become a key issue. Dynamic Bayesian networks (DBN) have been proved as relevant to perform reliability analysis as they can easily represent complex systems behaviors. Based on this formalism, graphical duration models (GDM) were developed by (Donat, et al., 2009) to set all kind of sojourn time distributions for each state of the system. Unlike to some Markovian approaches that impose exponential behavior, this approach could better model the exact degradation dynamic of real industrial systems. But, what commonly happens when the degradation process suddenly changes? The operator has to face with an unexpected increasing number of severe defects (and then a strong drop of its availability). These changes are generally due to either new component, introduced in the system for obsolescence reasons, or to changing operating conditions. The aim of the study introduced in this paper, focusing on Dynamic Maintenance Strategies, is to detect these drifts and to evaluate their impacts on the system’s behavior.
- Published
- 2013
40. Online predictive diagnosis of electrical train door systems
- Author
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Han, Yufei, Francois, Olivier, Same, Allou, Bouillaut, Laurent, Oukhellou, Latifa, Aknin, Patrice, Branger, Guillaume, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, BOMBARDIER TRANSPORT FRANCE SAS, and Cadic, Ifsttar
- Subjects
DIAGNOSTIC ,MAINTENANCE ,TRAIN - Abstract
Considering availability purposes for train transportation, passenger accesses (doors and steps) are often designated as critical systems. To improve global availability of its rolling stock, Bombardier Transportation (BT) aims at reinforcing its maintenance procedure by introducing predictive diagnosis. The SURFER project has been initiated to develop online and in-cars tools to early detect and prevent faults. In this paper, an overview of achieved progress with respect to online predictive diagnosis will be introduced. For this purpose, many signals are recorded using a test bench by BT: electrical motor intensity current, door displacement, binary indicators as door closed and locked. The paper focuses on designing a semi-Supervised discriminative probabilistic model that take into account contextual variables (train inclination or constraints due to passengers affluence) to perform a robust predictive diagnosis. The main steps of the proposed method are the followings: the segmentation of the provided signals into opening and closing phases, the extraction of relevant features from opening/closing phases, the setting of the discriminative diagnosis model based on statistical semi-supervised learning. The proposed approach is tested on signals collected from regional trains fleeting around Paris. It allows the earlier detection of anomalies, for instance, those due to maladjustments. The practical implementation of this approach will be detailed together with its preliminary results.
- Published
- 2013
41. State-space modeling of a sequence of curves application to the condition condition monitoring of railway switches
- Author
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Same, Allou, EL ASSAAD, Hani, Aknin, Patrice, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, and Cadic, Ifsttar
- Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other ,[SPI.OTHER] Engineering Sciences [physics]/Other ,SURVEILLANCE - Abstract
This article introduces a state-space model for the dynamic modeling of curve sequences within the framework of railway switches online monitoring. In this context, each curve has the peculiarity of being subject to multiple changes in regime. The proposed model consists of a specific latent variable regression model whose coefficients are supposed to evolve dynamically in the course of time. Its parameters are recursively estimated across a sequence of curves through an online Expectation-Maximization (EM) algorithm. The experimental study conducted on two real power consumption curve sequences from the French high speed network has shown encouraging results.
- Published
- 2013
42. A mixture of Kalman filters for online monitoring of railway switches
- Author
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Same, Allou, EL ASSAAD, Hani, Aknin, Patrice, Govaert, Gérard, Antoni, Marc, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Heuristique et Diagnostic des Systèmes Complexes [Compiègne] (Heudiasyc), Université de Technologie de Compiègne (UTC)-Centre National de la Recherche Scientifique (CNRS), SNCF, Direction Contrats et Services Clients, Pôle Technique Ingénierie de Maintenance, and Cadic, Ifsttar
- Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other ,DIAGNOSTIC ,[SPI.OTHER] Engineering Sciences [physics]/Other ,SURVEILLANCE - Abstract
International audience; Assessing the operating state of the railway infrastructure and rolling stock using condition measurements acquired through embedded sensors has become a powerful decision-making support for preventive maintenance strategies. This article introduces a dynamic approach for the online monitoring of railway switch operations. The method is based on modeling the power consumption curves acquired during successive switch operations using conjointly five polynomial regression models whose coefficients are dynamically estimated across a sequence of curves. The experimental study conducted on two real power consumption curve sequences from the French high speed network has shown encouraging results in terms of characterization of the temporal evolution of railway switch operations.
- Published
- 2013
43. A Probabilistic Graphical Models approach for rail prognosis based maintenance in a periodic observations context
- Author
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FOULLIARON, Josquin, Bouillaut, Laurent, Barros, Anne, Aknin, Patrice, ROZAS, Rony, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Laboratoire Modélisation et Sûreté des Systèmes (LM2S), Institut Charles Delaunay (ICD), and Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Troyes (UTT)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other ,MAINTENANCE - Abstract
In most industrial fields, and particularly in the railway industry, the optimization of maintenance policies has become a key issue. To address this problem, predictive maintenance seems to be one of the most effective known approaches. It consists of driving the maintenance process anticipating the evolution of the system state. A prediction process, called "prognosis" could also be introduced and it lays on the online estimation of the remaining useful life (RUL). Dynamic Bayesian networks (DBN) have been proved as relevant to perform reliability analysis as they can easily represent complex systems behaviors. Based on this formalism, graphical duration models (GDM) were developed by (Donat 2009) to set all kind of sojourn time distributions for each state of the system. Unlike to some Markovian approaches that impose exponential behavior, this approach could better model the exact degradation dynamic of real industrial systems. In our study, where time and states space are discretized, we consider rail degradation whom process is assumed to be monotone increasing. The real state of rails is unknown but periodically observed by an ultrasonic vehicle, characterized by its good detections rates, false alarms rates and non detection rates. This paper introduces an online RUL estimation algorithm based on the use of graphical duration models. The objective is both to evaluate the RUL and to adjust it, in real time, when a new observation is available. Then, the algorithm is applied to the rail degradation example to evaluate the quality of the RUL estimations. This paper will also provide some comparative results in respect of the considered degradation model (Markovian approach vs GDM). Finally, these RUL computations, and the associated estimations of the future system behavior, will be subsequently used to optimize the rail maintenance strategy and its diagnosis schedule.
- Published
- 2013
44. Un modèle dynamique à variables latentes pour le partitionnement de données temporelles
- Author
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EL ASSAAD, Hani, Same, Allou, Govaert, Gérard, Aknin, Patrice, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Heuristique et Diagnostic des Systèmes Complexes [Compiègne] (Heudiasyc), Université de Technologie de Compiègne (UTC)-Centre National de la Recherche Scientifique (CNRS), and Cadic, Ifsttar
- Subjects
[STAT.AP]Statistics [stat]/Applications [stat.AP] ,[STAT.AP] Statistics [stat]/Applications [stat.AP] ,CLASSIFICATION ,MODELE DYNAMIQUE - Abstract
National audience; Cet article aborde le problème de la classification des données temporelles en utilisant un mélange dynamique de lois gaussiennes dont les moyennes sont considérées comme des variables latentes qui évoluent suivant des marches aléatoires.
- Published
- 2013
45. Mod��le �� processus latent et algorithme EM pour la r��gression non lin��aire
- Author
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Chamroukhi, Faicel, Sam��, Allou, Govaert, G��rard, and Aknin, Patrice
- Subjects
Methodology (stat.ME) ,FOS: Computer and information sciences ,Statistics::Machine Learning ,FOS: Mathematics ,Statistics::Methodology ,Machine Learning (stat.ML) ,Statistics Theory (math.ST) ,Machine Learning (cs.LG) - Abstract
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. The model parameters are estimated by maximum likelihood performed via a dedicated expecation-maximization (EM) algorithm. An experimental study using simulated and real data sets reveals good performances of the proposed approach.
- Published
- 2013
- Full Text
- View/download PDF
46. Fuel Cell Health Monitoring Using Self Organizing Maps
- Author
-
ONANENA, Raissa, Oukhellou, Latifa, COME, Etienne, Jemei, Samir, Candusso, Denis, Hissel, Daniel, Aknin, Patrice, Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Direction scientifique (IFSTTAR/DS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Laboratoire Commun de Belfort : Hydrogène et Pile à Combustible pour les applications au transport (FC LAB), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Laboratoire Transports et Environnement (IFSTTAR/AME/LTE), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon-Université de Lyon-Laboratoire des Technologies Nouvelles (IFSTTAR/COSYS/LTN), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Technologie de Belfort-Montbeliard (UTBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Laboratoire des Technologies Nouvelles (IFSTTAR/COSYS/LTN), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Laboratoire Transports et Environnement (IFSTTAR/AME/LTE), and Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université de Lyon-Université de Lyon
- Subjects
lcsh:Computer engineering. Computer hardware ,DUREE DE VIE ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph] ,SURVEILLANCE ,[SPI.NRJ]Engineering Sciences [physics]/Electric power ,[PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph] ,lcsh:TP155-156 ,lcsh:TK7885-7895 ,lcsh:Chemical engineering ,[SPI.AUTO]Engineering Sciences [physics]/Automatic - Abstract
International audience; The problem of durability of fuel cell technology is central for its spreading and commercialization. There is therefore a growing need to build accurate diagnosis tools which can give the operating state of the fuel cell during their use. When supervised machine learning approaches are used to build such diagnosis tools, they generally require a large amount of labeled data. Collection and annotation of data can be either difficult to perform or time consuming. In this paper, authors are interested in the monitoring of fuel cells in an unsupervised framework, meaning that no labels are required to learn the diagnosis model. The aim is to build a monitoring tool able to easily visualize the State Of Health of full cells fromelectrochemical impedance spectroscopy measures, showing thus its evolution from fault free case ("normal" behaviour) to defective classes such as drying or flooding. The proposed approach is based on Self Organizing Maps (SOM) which have shown their performance to solve fault detection and prediction in many industrial systems. By automatically visualizing the data into a two-dimensional space, the interpretation of the results have become easy and instinctive. The approach also allows the clustering of the data into different groups of classes, thus enabling the classification of new observations. Experimental results carried out on real data sets have shown the efficiency of the proposed approach with respect to standard supervised and unsupervised classification approaches.
- Published
- 2013
47. Classification automatique de données temporelles en classes ordonnées
- Author
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Chamroukhi, Faicel, Samé, Allou, Aknin, Patrice, Govaert, Gérard, Heuristique et Diagnostic des Systèmes Complexes [Compiègne] (Heudiasyc), Université de Technologie de Compiègne (UTC)-Centre National de la Recherche Scientifique (CNRS), Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Laboratoire des Sciences de l'Information et des Systèmes (LSIS), Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Université de Toulon (UTLN)-Aix Marseille Université (AMU), Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/COSYS/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Direction scientifique (IFSTTAR/DS), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Govaert, Gérard, and Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Centre National de la Recherche Scientifique (CNRS)
- Subjects
algorithme CEM ,égression ,classification ,[STAT.TH] Statistics [stat]/Statistics Theory [stat.TH] ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,algorithme EM ,processus latent ,[STAT.TH]Statistics [stat]/Statistics Theory [stat.TH] ,[MATH.MATH-ST] Mathematics [math]/Statistics [math.ST] ,ComputingMilieux_MISCELLANEOUS - Abstract
National audience
- Published
- 2011
48. A dynamic probabilistic modeling of railway switches operating states
- Author
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Same, Allou, Chamroukhi, Faicel, Aknin, Patrice, Antoni, Marc, Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Laboratoire des Technologies Nouvelles (IFSTTAR/LTN), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), SNCF Direction de l'infrastructure, and parent
- Subjects
[SPI.OTHER]Engineering Sciences [physics]/Other ,MAINTENANCE ,COMMUTATEUR ,VOIE FERREE ,TELESURVEILLANCE - Abstract
WCRR 2011 - 9th World Congress on Railway Research, LILLE, FRANCE, 22-/05/2011 - 26/05/2011; The remote monitoring of the railway infrastructure and particularly the switch mechanism is of great interest for railway operators. The problem consists in detecting earlier the presence of defects in order to alert the concerned maintenance service before a breakdown occurs. For this purpose, this paper introduces a new probabilistic-based approach to dynamically modeling the evolution of condition measurements acquired during switch operations. It consists of two steps. The feature extraction from the electrical power consumption signals which aims at summarizing each signal by a low dimensional feature vector. Then, a specific autoregressive model is proposed to model the dynamical behavior of the switch mechanism.
- Published
- 2011
49. Modèle à processus latent et algorithme EM pour la régression non linéaire
- Author
-
Chamroukhi, Faicel, Samé, Allou, Govaert, Gérard, Aknin, Patrice, Heuristique et Diagnostic des Systèmes Complexes [Compiègne] (Heudiasyc), Université de Technologie de Compiègne (UTC)-Centre National de la Recherche Scientifique (CNRS), Génie des Réseaux de Transport Terrestres et Informatique Avancée (IFSTTAR/GRETTIA), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), and Govaert, Gérard
- Subjects
[STAT.TH] Statistics [stat]/Statistics Theory [stat.TH] ,[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST] ,[STAT.TH]Statistics [stat]/Statistics Theory [stat.TH] ,[MATH.MATH-ST] Mathematics [math]/Statistics [math.ST] ,ComputingMilieux_MISCELLANEOUS - Abstract
National audience
- Published
- 2011
50. Optimisation par algorithme génétique de la maintenance préventive dans un contexte de modélisation par modèles graphiques probabilistes
- Author
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Ayadi, Ines, Bouillaut, Laurent, Aknin, Patrice, Siarry, Patrick, Cadic, Ifsttar, Institut Pour la Maitrise des Risques, Génie des Réseaux de Transport et Informatique Avancée (INRETS/GRETIA), Institut National de Recherche sur les Transports et leur Sécurité (INRETS), Laboratoire des Technologies Nouvelles (INRETS/LTN), Laboratoire d'étude et de recherche en instrumentation, signaux et systèmes (LERISS), and EA412-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)
- Subjects
OPTIMISATION ,SYSTEME COMPLEXE ,[MATH.MATH-OC] Mathematics [math]/Optimization and Control [math.OC] ,[MATH.MATH-OC]Mathematics [math]/Optimization and Control [math.OC] ,ENTRETIEN - Abstract
International audience; Les équipements employés dans les milieux industriels, tels que les chaînes de production, l'ingénierie ou le transport, se présentent généralement sous la forme de systèmes complexes multi-composants et multi-états. L'état de ces systèmes est souvent affecté par les conditions d'usage. La compréhension de l'évolution au cours du temps des états de fonctionnement de ce type de système, nécessite l'élaboration de modèles dynamiques adaptés, généralement stochastiques. En complément de ces modèles de dégradation, la politique de maintenance déployée agit directement sur la dynamique d'apparition des états dégradés, selon que l'on choisit d'agir préventivement ou curativement. L'objectif de ce travail est, d'une part, de proposer, en se basant sur une approche de modélisation par réseaux bayésiens dynamiques, une fonction de coût permettant d'évaluer des politiques de maintenance. D'autre part, de mettre en oeuvre un algorithme d'optimisation de type génétique en vue de retenir la politique de maintenance préventive optimale. Dans cet article, on propose une fonction de coût associée à un cas d'étude (un système de distribution de fluides à 3 vannes) et un algorithme d'optimisation de type algorithme génétique. Le critère d'optimisation proposé utilise une modélisation stochastique de la dégradation du système basée sur une structure particulière des réseaux bayésiens dynamiques nommée Modèle Graphique de Durée (MGD). Ce critère de coût fait intervenir bien sûr les paramètres essentiels de la maintenance, tels que la probabilité d'effectuer une action de maintenance, son coût et sa durée, la disponibilité du système et les utilités associées aux états du système.
- Published
- 2010
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