International Professional University of Technology in Nagoya Repository
Not a member yet
15131 research outputs found
Sort by
Electric breakdown strength of new elastomer polymer sandwiched with compliant electrodes for soft electrostatic generators
No full textInternational audienc
Experimenting on Architectures for High Performance Computing
No full textNational audienceOverview of HPC architectures, of challenges of reproducible research, and of the Grid'5000 testbe
DMOS : A vous de jouer !
No full textNational audienceDepuis plus de 20 ans, l'équipe Intuidoc a développé un système complet de reconnaissance de documents : la méthode DMOS (Description et MOdification de la Segmentation). Cette méthode est basée sur trois niveaux : (1) des indices visuels, (2) un langage de description grammatical, le langage EPF, (3) un compilateur associé.La méthode DMOS a été largement testée dans des contextes variés, et a permis de mettre en place différents scénarios selon les problématiques étudiées. Nous mettons maintenant à disposition de la communauté, pour des fins de recherche, un environnement de développement contenant l'intégralité de la méthode DMOS
Observation et modélisation de la croissance de Postia placenta : de l'échelle discrète de la colonie à l'échelle macroscopique
No full textThe use of bio-based materials in thermally efficient buildings raises the question of the sustainability mainly due to fungal degradation. Among the wood-decay fungi, Postia placenta is one of the most common brown rot fungi, which are the most destructive due to their rapid decaying mechanisms. This work focused on the experimental observation and the modeling of fungal growth at three successive scales: the mycelial network (discrete scale), mycelial growth in homogeneous media (continuous scale) and mycelial growth in porous media (macroscopic scale).The experimental observation of the growth of Postia placenta was performed using confocal laser scanning microscopy to quantify the different growth mechanisms and obtain the growth parameters. A discrete model has been derived from this observation and is capable of generating mycelial networks extremely similar to the observed ones. A continuous formulation based on a reaction diffusion equation was developed from the radial biomass density of a mycelial network obtained in the discrete model. This continuous formulation was then used to derive an equivalent macroscale model able to account for fungal development in porous media. Simulations were performed on various periodic porous media. The parameters of the macroscale model was identified on the macroscopic fields obtained by averaging the local field over one periodic unit cell.L’utilisation de matériaux d’origine végétale dans les bâtiments thermiquement performants pose la question de la pérennité des ouvrages principalement à cause de la dégradation fongique. Postia placenta est une espèce des champignons provoquant la pourriture brune, qui est la plus destructrice pour les constructions en bois.Ce travail se concentre sur l’observation et la modélisation de la croissance de Postia placenta à trois échelles successives : l'arborescence du mycélium (échelle discrète), la croissance en milieu libre (échelle continue) et la croissance en milieu encombré (échelle macroscopique). L’observation expérimentale de la croissance de Postia placenta utilise un microscope confocal à balayage laser pour quantifier les différentes mécanismes et obtenir les paramètres de croissance. A partir de cette observation, un modèle discret capable de générer un mycélium de forme extrêmement similaire à celle observée a été imaginé, développé et validé. Ensuite, à partir des profils de biomasse moyennés selon le rayon des mycéliums simulés par le modèle discret, un modèle continu basé sur une équation de réaction diffusion a été identifié pour décrire l’évolution de la concentration de biomasse fongique. Ce modèle continu offre la possibilité de la transition de l’échelle locale vers l’échelle macroscopique. Pour cela, des simulations de la prolifération en environnement encombré sont obtenues à l'aide du modèle continu. Par prise de moyenne, les champs spatio-temporels obtenus permettent de déterminer les paramètres d'un modèle continu similaire, mais valable à l'échelle macroscopique, sur un milieu fictif qui prend en considération la morphologie des obstacles
Magneto-mechanical modeling of electrical steel sheets
No full textInternational audienceA simplified multiscale approach and a Helmholtz free energy based approach for modeling the magneto-mechanical behavior of electrical steel sheets are compared. The models are identified from uniaxial magneto-mechanical measurements of two different electrical steel sheets which show different magneto-elastic behavior. Comparison with the available measurement data of the materials shows that both models successfully model the magneto-mechanical behavior of one of the studied materials, whereas for the second material only the Helmholtz free energy based approach is successful
A Model for Accountable Ordinal Sorting
No full textInternational audienceWe address the problem of multicriteria ordinal sorting through the lens of accountability, i.e. the ability of a human decision-maker to own a recommendation made by the system. We put forward a number of model features that would favor the capability to support the recommendation with a convincing explanation. To account for that, we design a recommender system implementing and formalizing such features. This system outputs explanations under the form of specific argument schemes tailored to represent the specific rules of the model. At the end, we discuss possible and promising argumentative perspectives
Scalable Fine-Grained Proofs for Formula Processing
No full textWe present a framework for processing formulas in automatic theorem provers, with generation of detailed proofs. The main components are a generic contextual recursion algorithm and an extensible set of inference rules. Clausification, skolemization, theory-specific simplifications, and expansion of 'let' expressions are instances of this framework. With suitable data structures, proof generation adds only a linear-time overhead, and proofs can be checked in linear time. We implemented the approach in the SMT solver veriT. This allowed us to dramatically simplify the code base while increasing the number of problems for which detailed proofs can be produced, which is important for independent checking and reconstruction in proof assistants
Scalp EEG Activity During Simple and Combined Motor Imageries to Control a Robotic Arm
No full textInternational audienceIn this article, we study how combined motor imageries can be detected to deliver more commands in a Brain-Computer Interface for controlling a robotic arm. Motor imageries are a major way to deliver commands in BCI. Nevertheless only a few systems use more than three motor imageries: right hand, left hand and feet. Combining them allow to get four additional commands. We present an electrophysiological study to show that i) simple motor imageries have mainly an electrical modulation over the cortical area related the body part involved in the imagined movement and that ii) combined motor imageries reflect a superposition of the electrical activity of simple motor imageries. A shrinkage linear discriminant analysis has been used to test as a first step how a resting state and seven motor imageries can be detected. 11 healthy subjects participated in the experiment for which an intuitive assignment has been done to associate motor imageries and movements of the robotic arm with 7 degrees of freedom
Quality Gain Analysis of the Weighted Recombination Evolution Strategy on General Convex Quadratic Functions
No full textInternational audienceWe investigate evolution strategies with weighted recombi-nation on general convex quadratic functions. We derive the asymptotic quality gain in the limit of the dimension to infinity, and derive the optimal recombination weights and the optimal step-size. This work is an extension of previous works where the asymptotic quality gain of evolution strategies with weighted recombination was derived on the infinite dimensional sphere function. Moreover, for a finite dimensional search space, we derive rigorous bounds for the quality gain on a general quadratic function. They reveal the dependency of the quality gain both in the eigenvalue distribution of the Hessian matrix and on the recombina-tion weights. Taking the search space dimension to infinity , it turns out that the optimal recombination weights are independent of the Hessian matrix, i.e., the recombination weights optimal for the sphere function are optimal for convex quadratic functions
Quantization-aware Parameter Estimation for Audio Upmixing
No full textInternational audienceUpmixing consists in extracting audio objects out of their downmix, given some parameters computed beforehand at a coding stage. It is an important task in audio processing with many applications in the entertainment industry. One particularly successful approach for this purpose is to compress the audio objects through nonnegative matrix factorization (NMF) parameters at the coder, to be used for separating the downmix at the decoder. In this paper, we focus on such NMF methods for audio compression, which operate at very low parameter bitrates. In existing methods, parameter estimation and quantization are conducted independently. Here, we propose two extensions: first, we jointly estimate and quantize the parameters at the coder to ensure good reconstruction at the decoder. Second, we propose a parameter refinement method operated at the decoder, that benefits from priors induced by quantization to yield better performance. We show that our contributions outperform existing baseline methods