Semantic and Visual Similarities for Efficient Knowledge Transfer in CNN Training

International audienceIn recent years, representation learning approaches have disrupted many multimedia computing tasks. Among those approaches, deep convolutional neural networks (CNNs) have notably reached human level expertise on some constrained image classification tasks. Nonetheless, training CNNs from scratch for new task or simply new data turns out to be complex and time-consuming. Recently, transfer learning has emerged as an effective methodology for adapting pre-trained CNNs to new data and classes, by only retraining the last classification layer. This paper focuses on improving this process, in order to better transfer knowledge between CNN architectures for faster trainings in the case of fine tuning for image classification. This is achieved by combining and transfering supplementary weights, based on similarity considerations between source and target classes. The study includes a comparison between semantic and content-based similarities, and highlights increased initial performances and training speed, along with superior long term performances when limited training samples are available

Ressources distribuées et interactions entre élèves au sein d’un groupe d’apprentissage : une étude de cas en éducation physique et sportive

Cette étude visait à analyser l’activité collective d’élèves engagés dans la préparation d’un triathlon athlétique par équipe durant un cycle d’éducation physique. Il s’agissait plus précisément de comprendre la façon dont les interactions entre les élèves intervenaient dans l’activité individuelle de chacun. Elle a été conduite en référence au cadre théorique et méthodologique du « cours d’action ». Le recueil des données a été effectué en enregistrant en vidéo les actions et verbalisations des élèves et des enseignants dans les situations de classe et en menant à l'issue de chaque leçon des entretiens d'autoconfrontation avec les élèves participant à l'étude. L'analyse révèle, d’une part, que les configurations d’activité collective générées par le dispositif de travail par équipe offrent aux élèves un ensemble de ressources distribuées pour apprendre, et d’autre part, que l’activité collective des élèves produit des formes originales de coopération et de tutelle non prescrites par l’enseignant. Ces résultats ouvrent des pistes de conception de situations d’apprentissage coopératif en éducation physique.The aim of the study was to analyze students’ collective activity when involved in the team preparation of an athletic triathlon during a physical education unit. It was more precisely designed to understanding how interactions between students influenced student learning. The study was carried out referring to the “course of action” theoretical and methodological framework. The results show, first, that the configurations of collective activity generated by this pedagogical procedure offered students a set of distributed resources for learning, and secondly, that the collective activity of students produced original forms of cooperation and tutoring that was not prescribed by the teacher. These results open original ways to design cooperative learning tasks in physical education

PLM-based approach for collaborative design between OEM and suppliers : case study of aeronautic industry.

To achieve different assembly operations on the aircraft structure, the aeronautic OEM needs to create and manage various fixture tools. To cope with these needs, the OEM begun to adopt the supplier integration into the tooling development process. This paper presents a conceptual PLM-based approach to support new business partnership of different suppliers. The new business partnership aims to improve the role of supplier in the different tasks of design, configuration and fabrication of the tooling. The use of the PLM concepts is proposed to enhance the collaboration between OEM and the equipment's suppliers. UML models are proposed to specify the structure of the PLM solution. These models describe the relation between the aircraft assembly project, and the tooling design process

A construção conjunta de um observatório e de um objeto teórico : o exemplo do relato da experiência e do espaço de ação

Este artigo, baseado num estudo realizado com uma turma de 26 alunos que faziam parte de um projeto anual denominado “Arctic Kayak”, tem um desafio duplo. O primeiro desafio é apresentar a dinâmica da construção conjunta, através de voltas e reviravoltas, entre um observatório e um objeto teórico. O segundo desafio é apresentar novas noções que possam enriquecer o programa de pesquisa do "curso de ação". A primeira delas é a noção de "relato de experiência" que permite conceber um observatório que visa abordar a experiência de um importante grupo de atores num período de tempo relativamente longo. Essas histórias oferecem uma descrição condensada da experiência de todos os alunos durante as aulas de caiaque que levam a diferentes eixos de análise. A segunda noção é a de "espaço de ação", que é uma redução do objeto teórico "curso de experiência". Corresponde, para um ator e para uma determinada unidade de tempo, ao conjunto de elementos do ambiente aos quais esse ator atribui qualidades particulares. A análise dos espaços de ação dos alunos permitiu identificar evoluções e transformações típicas nos seus julgamentos percetivos durante as aulas. Esses resultados especificaram a hipótese dos três processos (em situação, em corporação, em cultura) da apropriação proposta por Theureau.El desafío de este artículo basado en un estudio llevado a cabo con un curso de 26 alumnos que formaron parte de un proyecto anual llamado “Kayak ártico”, es doble. El primer desafío consiste en presentar la dinámica de construcción conjunta, a través de idas y vueltas , entre un observatorio y un objeto teórico. El segundo desafío es presentar nuevas nociones susceptibles de enriquecer el programa de investigación del "curso de acción". La primera de ellas es la noción de “relato de experiencia” que permite concebir un observatorio que apunte a abordar la experiencia de un colectivo importante de actores en un periodo de tiempo relativamente largo. Estos relatos ofrecen una descripción condensada de la experiencia del conjunto de los alumnos durante las clases de kayak que conducen a diferentes ejes de análisis. La segunda noción es la de “espacio de acción”, que es una reducción del objeto teórico “curso de la experiencia”. Corresponde, para un actor, y para una unidad de tiempo determinada, al conjunto de los elementos del entorno a los que ese actor atribuye cualidades particulares. El análisis de los espacios de acción de los alumnos permitió identificar evoluciones y transformaciones típicas en sus juicios perceptivos durante las clases. Estos resultados especificaron la hipótesis de los tres procesos (in-situación, in-corporación, in-culturación) de la apropiación propuesta por Theureau.L’enjeu de cet article, qui s’appuie sur une étude conduite avec une classe de 26 élèves engagés dans un projet annuel “ Kayak arctique », est double. Le premier est de présenter la dynamique de construction conjointe, par des allers et retours, entre un observatoire et un objet théorique. Le deuxième enjeu est de présenter des nouvelles notions susceptibles d’enrichir le programme de recherche du cours d’action. La première est la notion de “ récit d’expérience » qui permet de concevoir un observatoire visant à appréhender l’expérience d’un collectif d’acteurs important sur une temporalité relativement longue. Ces récits offrent une description condensée de l’expérience de l’ensemble des élèves au cours des leçons de kayak, ouvrant vers différents axes d’analyse. La deuxième notion est celle d’” espace d’actions », qui est une réduction de l’objet théorique “ cours d’expérience ». Il correspond, pour un acteur, et pour une unité de temps donnée, à l’ensemble des éléments de l’environnement auxquels il attribue des qualités particulières. L’analyse des espaces d’actions des élèves a permis de repérer des évolutions et des transformations typiques dans les jugements perceptifs des élèves au cours des leçons. Ces résultats ont précisé l’hypothèse des trois processus (in-situation, in-corporation, in-culturation) de l’appropriation proposée par Theureau.The aim of this paper, based on a study conducted with a 26-student class engaged in an annual “Arctic Kayak” project, is twofold. The first challenge is to present the dynamics of joint construction, going back and forth between observation analysis and theoretical object. The second is to introduce two new concepts that might benefit the course-of-action research program. The first, “story of experience”, helps designing and conducting observation research to collect and analyze the experience of large groups of actors over a relatively long period of time. Such stories offer a condensed description of students’ individual experiences during the kayak classes, providing multiple angles of analysis. The second concept is “action field”, which is a subset of the “course-of-experience” theoretical object. For an actor and a given unit of time, this corresponds to all elements of its environment to which it attributes characteristics. Analysis of the students’ action fields allowed us to identify evolutions and transformations which are typical of the students’ perceptual judgments during classes. These results clarify the hypothesis of the three processes (in-situation, in-corporation, in-culturation) of appropriation proposed by Theureau

Improved Video Content Indexing by Multiple Latent Semantic Analysis

Low-level features are now becoming insufficient to build efficient content-based retrieval systems. Users are not interested any longer in retrieving visually similar content, but they expect retrieval systems to also find documents with similar semantic content. Bridging the gap between low-level features and semantic content is a challenging task necessary for future retrieval systems. Latent Semantic Analysis (LSA) was successfully introduced to efficiently index text documents by detecting synonyms and the polysemy of words. We have successfully proposed an adaptation of LSA to model video content for object retrieval and semantic content estimation. Following this idea we now present a new model composed of multiple LSA's (M-LSA) to better represent the video content. In the experimental section, we make a comparison of LSA and M-LSA on two problems, namely object retrieval and semantic content estimation

Innovative PLM-based approach for collaborative design between OEM and suppliers: Case study of aeronautic industry

Abstract: To achieve different assembly operations on the aircraft structure, the aeronautic OEM needs to create and manage various fixture tools. To cope with these needs, the OEM begun to adopt the supplier integration into the tooling development process. This paper presents a conceptual PLM-based approach to support new business partnership of different suppliers. The new business partnership aims to improve the role of supplier in the different tasks of design, configuration and fabrication of the tooling. The use of the PLM concepts is proposed to enhance the collaboration between OEM and the equipment's suppliers. UML models are proposed to specify the structure of the PLM solution. These models describe the relation between the aircraft assembly project, and the tooling design process

Characterising molecules for fundamental physics: an accurate spectroscopic model of methyltrioxorhenium derived from new infrared and millimetre-wave measurements

Precise spectroscopic analysis of polyatomic molecules enables many striking advances in physical chemistry and fundamental physics. We use several new high-resolution spectroscopic devices to improve our understanding of the rotational and rovibrational structure of methyltrioxorhenium (MTO), the achiral parent of a family of large oxorhenium compounds that are ideal candidate species for a planned measurement of parity violation in chiral molecules. Using millimetre-wave and infrared spectroscopy in a pulsed supersonic jet, a cryogenic buffer gas cell, and room temperature absorption cells, we probe the ground state and the Re=O antisymmetric and symmetric stretching excited states of both CH3 187 ReO3 and CH3 185 ReO3 isotopologues in the gas phase with unprecedented precision. By extending the rotational spectra to the 150-300 GHz range, we characterize the ground state rotational and hyperfine structure up to J = 43 and K = 41, resulting in refinements to the rotational, quartic and hyperfine parameters, and the determination of sextic parameters and a centrifugal distortion correction to the quadrupolar hyperfine constant. We obtain rovibrational data for temperatures between 6 and 300 K in the 970-1015 cm-1 range, at resolutions down to 8 MHz and accuracies of 30 MHz. We use these data to determine more precise excited-state rotational, Coriolis and quartic parameters, as well as the ground-state centrifugal distortion parameter D K of the 187 Re isotopologue. We also account for hyperfine structure in the rovibrational transitions and hence determine the upper state rhenium atom quadrupole coupling constant eQq'

High resolution spectroscopy of methyltrioxorhenium: towards the observation of parity violation in chiral molecules

Originating from the weak interaction, parity violation in chiral molecules has been considered as a possible origin of the biohomochirality. It was predicted in 1974 but has never been observed so far. Parity violation should lead to a very tiny frequency difference in the rovibrational spectra of the enantiomers of a chiral molecule. We have proposed to observe this predicted frequency difference using the two photon Ramsey fringes technique on a supersonic beam. Promising candidates for this experiment are chiral oxorhenium complexes, which present a large effect, can be synthesized in large quantity and enantiopure form, and can be seeded in a molecular beam. As a first step towards our objective, a detailed spectroscopic study of methyltrioxorhenium (MTO) has been undertaken. It is an ideal test molecule as the achiral parent molecule of chiral candidates for the parity violation experiment. For the 187Re MTO isotopologue, a combined analysis of Fourier transform microwave and infrared spectra as well as ultra-high resolution CO2 laser absorption spectra enabled the assignment of 28 rotational lines and 71 rovibrational lines, some of them with a resolved hyperfine structure. A set of spectroscopic parameters in the ground and first excited state, including hyperfine structure constants, was obtained for the antisymmetric Re=O stretching mode of this molecule. This result validates the experimental approach to be followed once a chiral derivative of MTO will be synthesized, and shows the benefit of the combination of several spectroscopic techniques in different spectral regions, with different set-ups and resolutions. First high resolution spectra of jet-cooled MTO, obtained on the set-up being developed for the observation of molecular parity violation, are shown, which constitutes a major step towards the targeted objective.Comment: 20 pages, 6 figure