Antoine Chambaz

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Neural integrators and working memory rely on persistent activity, a widespread neural phenomenon potentially involving persistent sodium conductances. Using a unique combination of voltage-clamp, dynamic-clamp, and frequency-domain techniques, we have investigated the role of voltage-dependent conductances on the dendritic electrotonic structure of neurons(More)
We address the issue of order identification for hmm with Poisson and Gaussian emissions. We prove information-theoretic bic-like mixture inequalities in the spirit of (Finesso, 1991; Liu & Narayan, 1994; Gassiat & Boucheron, 2003). These inequalities lead to consistent penalized estimators that need no prior bound on the order nor on the parameters of the(More)
We study a variant of the multi-armed bandit problem with multiple plays in which the user wishes to sample the m out of k arms with the highest expected rewards, but at any given time can only sample ` ≤ m arms. When ` = m, Thompson sampling was recently shown to be asymptotically efficient. We derive an asymptotic regret lower bound for any uniformly(More)
PURPOSE To study whether plica semilunaris (PS) temporal ectopia is associated with primary nasal pterygia and whether such hypothetical ectopia is linked to with-the-rule astigmatism so that a discussion of the clinical and surgical implications of such possible findings might take place. METHODS Cross-section observational study of 208 consecutive eyes(More)
This paper deals with order identification for Markov chains with Markov regime (MCMR) in the context of finite alphabets. We define the joint order of a MCMR process in terms of the number k of states of the hidden Markov chain and the memory m of the conditional Markov chain. We study the properties of penalized maximum likelihood estimators for the(More)
The most important knowledge in the area of biology currently consists of raw text documents. Bibliographic databases of biomedical articles can be searched, but an efficient procedure should evaluate the relevance of documents to biology. In genetics, this challenge is even trickier, because of the lack of consistency in genes' naming tradition. We aim to(More)
The efficiency of two Bayesian order estimators is studied under weak assumptions. By using nonparametric techniques, we prove new nonasymptotic underestimation and overestimation bounds. The bounds compare favorably with optimal bounds yielded by the Stein lemma and also with other known asymptotic bounds. The results apply to mixture models. In this case,(More)
This article contributes to the search for a notion of postural style, focusing on the issue of classifying subjects in terms of how they maintain posture. Longer term, the hope is to make it possible to determine on a case by case basis which sensorial information is prevalent in postural control, and to improve/adapt protocols for functional(More)
The concomitant emergence of big data, explosion of ubiquitous computational resources and democratization of the access to more powerful computing make it necessary and possible to rethink pragmatically the practice of statistics. While numerous machine learning methods provide much ever easier access to datamining tools and sophisticated prediction, there(More)