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Search Results: 1 - 10 of 237877 matches for " Le BouquinJèannes Régine "
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基于通用赤池信息量准则改进维纳-格兰杰因果索引算法的颅内脑电效应连通性研究
Research on effective connectivity of intracerebral electroencephalogram based on Wiener-Granger Causality Index modified by generalized Akaike’s Information Criterion

杨淳沨, 向文涛, 伍家松, 孔佑勇, 姜龙玉, Le BouquinJèannes Régine, 舒华忠
- , 2018, DOI: 10.7507/1001-5515.201709032
Abstract: 本文的目标是处理并分析使用深度电极在难治性癫痫患者癫痫发作期间其大脑皮层中记录到的癫痫脑电信号间的大脑效应连通性。维纳-格兰杰因果索引算法是一种众所周知的检测脑电信号间大脑效应连通性的有效方法。它是一种基于线性自回归模型的方法,而模型参数估计问题在其用于脑电因果效应连通性研究中的计算准确性与鲁棒性方面起着至关重要的作用。本文针对这一问题,使用了我们提出的改进的赤池信息量准则来估计算法中自回归模型的模型阶数,以提高维纳-格兰杰因果索引算法检测大脑效应连通性的性能。实验仿真结果表明:不管是在线性随机系统中还是在能生成模拟癫痫信号的生理模型中,该改进的维纳-格兰杰因果索引算法在检测脑效应连通性上都表现出良好的鲁棒性。
The objective is to deal with brain effective connectivity among epilepsy electroencephalogram (EEG) signals recorded by use of depth electrodes in the cerebral cortex of patients suffering from refractory epilepsy during their epileptic seizures. The Wiener-Granger Causality Index (WGCI) is a well-known effective measure that can be useful to detect causal relations of interdependence in these kinds of EEG signals. It is based on the linear autoregressive model, and the issue of the estimation of the model parameters plays an important role in the calculation accuracy and robustness of WGCI to do research on brain effective connectivity. Focusing on this issue, a modified Akaike’s information criterion algorithm is introduced in the computation of the WGCI to estimate the orders involved in the underlying models and in order to advance the performance of WGCI to detect brain effective connectivity. Experimental results support the interesting performance of the proposed algorithm to characterize the information flow both in a linear stochastic system and a physiology-based model.
Texts and Identities in the Early Middle Ages
Régine Le Jan
Bulletin du Centre d’études Médiévales d’Auxerre , 2008, DOI: 10.4000/cem.7552
Abstract: Le groupe de recherches doctorales Texts and Identities in the Early Middle Ages se réunira au Centre d’études médiévales d’Auxerre du 17 au 19 octobre pour sa réunion annuelle. Le groupe a été constitué à l’initiative des professeurs Mayke de Jong (Utrecht), Régine Le Jan (Paris), Rosamond McKitterick (Cambridge), Walter Pohl (Vienne) et Ian Wood (Leeds), qui ont décidé de faire bénéficier leurs doctorants de leur expérience du travail en commun. Depuis douze ans, des doctorants venus de...
Biotransformation of anthracene and fluoranthene by Absidia fusca Linnemann
Villemain,Danièle; Guiraud,Pascale; Bordjiba,Ouahiba; Steiman,Régine;
Electronic Journal of Biotechnology , 2006,
Abstract: a strain of absidia fusca was isolated from a pesticide-contaminated soil (annaba, algeria). the biotransformation capability of this strain towards two polycyclic aromatic hydrocarbons (pahs): anthracene and fluoranthene was compared to that exhibited by another strain of a. fusca isolated from a non-contaminated milieu and considered as a control. the results obtained were statistically analyzed and showed that the strain isolated from the contaminated soil was more efficient than the control to remove anthracene from the medium, during all the kinetics (90% removed versus 45% after 24 hrs). concerning fluoranthene, the amount removed by both strains was very high during the first 24 hrs however the control strain was slightly more efficient (94% versus 89%) while the results were similar for the two strains during the rest of the kinetics. this study reveals for the first time the potential interest of the species a. fusca for the bioremediation of pahs.
Comparison of Synchronization Indices: Behavioral Study
Pierre Dugué,Régine Le Bouquin-Jeannès,Gérard Faucon
EURASIP Journal on Advances in Signal Processing , 2009, DOI: 10.1155/2009/510235
Abstract: The synchronization of a neuronal response to a given periodic stimulus is usually measured by Goldberg and Brown's vector strength metric. This index does not take omitted spikes into account. This particular limitation has motivated the development of two new indices: the corrected vector strength index and the corrected phase variance index, both including a penalty factor linked to the firing rate. In this paper, a theoretical study on the normalization of the corrected phase variance index is conducted. Both indices are compared to four existing ones using a simulated dataset which considers three desynchronizing disturbances: irregularity in firing, added spikes, and omitted spikes. In the case of unimodal responses, the two new indices are satisfying and appear the more promising in the case of real signals. In the multimodal case, the entropy-based index is better than the others even if this index is not drawback-free.
A Two-Sensor Noise Reduction System: Applications for Hands-Free Car Kit
Gérard Faucon,Régine Le Bouquin-Jeannès,Alexandre Guérin
EURASIP Journal on Advances in Signal Processing , 2003, DOI: 10.1155/s1687617203305098
Abstract: This paper presents a two-microphone speech enhancer designed to remove noise in hands-free car kits. The algorithm, based on the magnitude squared coherence, uses speech correlation and noise decorrelation to separate speech from noise. The remaining correlated noise is reduced using cross-spectral subtraction. Particular attention is focused on the estimation of the different spectral densities (noise and noisy signals power spectral densities) which are critical for the quality of the algorithm. We also propose a continuous noise estimation, avoiding the need of vocal activity detector. Results on recorded signals are provided, showing the superiority of the two-sensor approach to single microphone techniques.
On the Evaluation of the Conversational Speech Quality in Telecommunications
Marie Guéguin,Régine Le Bouquin-Jeannès,Valérie Gautier-Turbin,Gérard Faucon
EURASIP Journal on Advances in Signal Processing , 2008, DOI: 10.1155/2008/185248
Abstract: We propose an objective method to assess speech quality in the conversational context by taking into account the talking and listening speech qualities and the impact of delay. This approach is applied to the results of four subjective tests on the effects of echo, delay, packet loss, and noise. The dataset is divided into training and validation sets. For the training set, a multiple linear regression is applied to determine a relationship between conversational, talking, and listening speech qualities and the delay value. The multiple linear regression leads to an accurate estimation of the conversational scores with high correlation and low error between subjective and estimated scores, both on the training and validation sets. In addition, a validation is performed on the data of a subjective test found in the literature which confirms the reliability of the regression. The relationship is then applied to an objective level by replacing talking and listening subjective scores with talking and listening objective scores provided by existing objective models, fed by speech signals recorded during the subjective tests. The conversational model achieves high performance as revealed by comparison with the test results and with the existing standard methodology ¢ € E-model, ¢ € presented in the ITU-T (International Telecommunication Union) Recommendation G.107.
Primeiro os amigos: os aniversários da infancia, dar e receber
Sirota, Régine;
Educa??o & Sociedade , 2005, DOI: 10.1590/S0101-73302005000200012
Abstract: ever since childhood birthday parties allow a process of socialization. such ritual, which usually gathers children of a same age group, is an opportunity to exchange presents: gifts and counter-gifts structure the sequences of birthday parties. an ethnological approach thus enables to seize the contribution of each social actor (children, parents, relatives, and friends) in the social constructions of this ritual. presents are the object of a real negotiation implying a permanent confrontation of norms and values through which a social link is built.
Emergência de uma sociologia da infancia: evolu??o do objeto e do olhar
Sirota, Régine;
Cadernos de Pesquisa , 2001, DOI: 10.1590/S0100-15742001000100001
Abstract: this is an introductory article in the discussion of the emergence of a sociology of childhood, which seeks to contemplate the evolution of the object and the perspective of analysis recorded in the 90s; it focuses on french language production. the text presents and discusses the different elements and main issues that result from the emergence of the field, seeking to put them in synergy starting with the retaking of the proposals of the authors invited to participate in issues 2 and 3 of éducation et societés magazine dedicated to the theme.
Géométrie, graphiques, fonctions au collège
Douady,Régine;
Revista electr?3nica de investigaci?3n en educaci?3n en ciencias , 2011,
Abstract: mathematical learning is a long term process that occurs, usually, in an institutional structure: the school. the student builds his knowledge over the years, in an interactive relationship with his teachers, other students in his class and all the other sources that social life makes available. in this text, we present a set of problems where the mathematical subject is the notion of approximation. it is treated at a time of the syllabus: 12-15-year-old students, in a contextualized way. it is only an approach; the question of the error calculation is not addressed. numbers and measures are there involved in the different frameworks in interaction: numerical, geometric, functional, and graphic. there, we explain our didactic choices and the reasons for the election of the engineering proposed. the reference is the tool-object dialectic and the frameworks interplay. it offers us a table to elaborate the sequences of class, and also to report and analyze the relations between teacher and students: who is responsible for what, who does what. the teacher has leeway to organize and lead his teaching; he has his expectations concerning students. we make reference here.
Géométrie, graphiques, fonctions au collège
Régine Douady
Revista electr?3nica de investigaci?3n en educaci?3n en ciencias , 2011,
Abstract: L'apprentissage des mathématiques s'inscrit sur le long terme et en général dans une structure institutionnelle : l'école. L'apprenant construit sa connaissance au fil des années, dans un rapport interactif avec ses enseignants, les autres élèves de sa classe et toutes les autres sources que la vie sociale met à sa disposition.Dans le texte ci-dessous, nous présentons un ensemble de problèmes dont l'enjeu mathématique est la notion d'approximation traitée à un moment de la scolarité : élèves de 12-15 ans, de fa on contextualisée. Ce n'est qu'une approche, la question du calcul d'erreur n'est pas abordée. Nombres et mesures y sont impliqués dans différents cadres en interaction : numérique, géométrique, fonctionnel, graphique. Nous y expliquons nos choix didactiques et les raisons des choix de l'ingénierie proposée. La référence est la dialectique outil/objet et jeux de cadres. Elle nous offre une grille pour élaborer les séquences de classe et aussi pour repérer et analyser les relations entre l'enseignant et les élèves : qui est responsable de quoi, qui fait quoi. L'enseignant a des marges de manoeuvre pour organiser et conduire son enseignement, il a des attentes concernant les élèves. Nous y faisons référence.
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