International Professional University of Technology in Nagoya Repository
Not a member yet
15131 research outputs found
Sort by
Can Synthetic Data Handle Unconstrained Gaze Estimation ?
No full textNational audienceIn this article, we aim at solving unconstrained gaze estimation problem using appearance-based approach. Unlike previous methods working in relatively constrained environment , we propose an approach that allows free head motion and significant user-sensor distances using RGB-D sensor. Our paper presents the following contributions : (i) A direct estimation by inferring gaze information from RGB eyes and depth face appearances ;(ii) A channel selection strategy during the learning to evaluate the involvement of each channel in the final prediction ; (iii) Adapting a 3D face morphable model by integrating a parametric gaze model to render an important synthetic RGB-D training set. We also collect real labeled samples using Kinect sensor that allows for evaluating the potential of synthetic learning in handling real configurations and establish an objective comparison with real learning. Results on several users demonstrate the great potential of our approach
VOCAL – A Verified OCAml Library
No full textML Family Workshop 2017▼AbstractLibraries are the basic building blocks of any realistic programming project. It is thus of utmost interest for a programmer to build her software on top of bug-free libraries. We present the ongoing VOCAL project, which aims at building a mechanically verified library of general-purpose data structures and algorithms, written in the OCaml language
Long-Range Antenna Systems for In-Body Biotelemetry: Design Methodology and Characterization Approach
No full textInternational audienceLong-range in-body biomedical telemetry enables monitoring of physiological parameters while maintaining mobility and freedom of movement. This emerging technology creates new applications in medicine, clinical research, wellness, and defense. Current in-body biotelemetry devices operate within about a meter around a user that limits their applicability. Here we examine the variety of approaches that, combined, can significantly extend the operating range. The radiation efficiency is constrained by attenuation and reflection losses in tissues. First, choosing an optimal operating frequency can minimize the losses. A specific antenna design is then required to decouple the antenna from a body. Two successful antenna design approaches are reviewed: (1) using loop antennas and (2) dielectrically loaded microstrip antennas. On-body matching layers and repeaters can be used to further improve power transmission. Finally, we present the radiation characterization method for in-body antennas in spherical phantoms with a direct illumination technique using an analog fiber optic lin
Une interprétation probabiliste des informations de factivité
No full textInternational audienceWe present a new formalisation of factuality: the dimension representing the degree of belief of a source (e.g. the author or any other agent mentionned in a text) for a given eventuality. We lay emphasis on the dynamic aspect of this notion and on its interactions with discourse structure. We show how an interpretation in terms of sets of probabilities solves the main problems arising out of the previous formalisation on the computation of coherent values of factuality at the discourse level.Nous présentons une nouvelle formalisation de la factivité, la dimension représentant le degré de croyance qu'une source – l'auteur ou tout autre agent mentionné dans un texte – accorde à une éventualité donnée. Nous insistons sur l'aspect dynamique de cette notion ainsi que sur ses interactions avec la structure discursive. Nous montrons comment une interprétation en termes d'ensembles de probabilités permet de s'affranchir des principaux problèmes que posait la formalisation utilisée dans les travaux précédents au calcul d'une factivité cohérente à l'échelle du texte dans sa totalité
Intégration entre services hospitaliers : management des opérations en cancérologie
No full textThis dissertation addresses the challenge of coordinating hospital services. We take an integrated view on care delivery and the various units involved in a care process, with a case study in outpatient chemotherapy process at Henri Mondor hospital, Créteil, France. We tackle three research questions :1. How should a change program in a multi-department setting be designed and managed?2. How can one improve outpatient chemotherapy delivery?3. Why do strategic plans look so disconcerting and disappointing in public academic medical centers, compared to otherindustrial organizations, when similar methods are applied?Our main research method is action-research. During reorganization projects, we adapt and combine methods from operational research and industrial engineering in order to integrate hospitals’ specificities. We propose and evaluate reorganisation methods focused on interdepartmental coordination, and we contribute to a better knowledge of the specific environment of hospitals, which is quite different from the contexts in which industrial engineering traditionally developed.Ces travaux s’intéressent à la coordination entre services au sein d’un hôpital. Il s’agit d’améliorer la prise en charge des patients en prenant une vision de leur parcours qui intègre toutes les unités impliquées. Nous nous sommes particulièrement intéressés au cas de la chimiothérapie ambulatoire, en partenariat avec l’hôpital Henri Mondor de Créteil. Trois questions sont traitées :1. Comment concevoir et mener un programme de changement dans un contexte multi-services à l’hôpital ?2. Comment améliorer la délivrance des chimiothérapies ambulatoires ?3. Pourquoi la planification stratégique dans les Centre Hospitalo-Universitaires donne-t-elle des résultats décevants, comparés aux contextes industriels où ces approches ont été appliquées avec succès ?Pour répondre, notre principale méthode d’investigation a été la recherche-action. Dans le cadre de projets de réorganisation à l’hôpital Henri Mondor, nous avons adapté et combiné des méthodes de recherche opérationnelle et de génie industriel pour prendre en compte les spécificités du contexte hospitalier. Nos travaux aboutissent à la proposition et à l’évaluation de méthodes de réorganisation centrées sur la coordination entre services, et sur une meilleure connaissance de l’environnement spécifique de l’hôpital, un contexte différent de ceux où s’est traditionnellement développé le génie industriel
Couplage de rapporteurs génétiques et d’une molécule active pour l’étude de la dispersion de biofilms.
No full textBiofilms are microbial communities adhering to a surface and embedded in a self-produced polymeric substance, called extracellular matrix. By being ubiquitous in nature, biofilms colonize numerous environments, and they often cause serious problems for both health and industry sectors. Dispersion is one of the strategies for fighting biofilms. A fatty acid, cis-2-decenoic acid (CDA), seems to be promising for dispersing biofilms by the extent of its action on different species of microbes. The aim of this thesis work is to investigate the mechanisms of biofilm dispersion of the bacterial species Escherichia coli (E. coli) by the model molecule CDA. Does CDA modify the biofilm structures or does it induce a genetic response from bacteria during dispersion? To answer these questions, E. coli biofilm dispersal has been studied in situ in microfluidic chambers by confocal laser scanning microscopy (CLSM). Specific bacterial strains have been developed by cloning promoters of interest in transcriptional fusion with a gene encoding for a green fluorescent protein. The results confirm the dispersing activity of CDA with a significant decrease of biomass, biofilm average thickness and area over biofilm depth. A novel tool for analyzing CLSM images has been developed in collaboration in order to measure the biofilm structural properties as a function of in situ fluorescence intensity of the studied reporter. The results indicate an increase in the mean fluorescence intensity of the biofilms after dispersion with CDA, at a global level for the whole biofilm and at a local scale by considering a biofilm segmentation into microcolonies. These results evoke a change in gene expression by bacteria in the presence of CDA. Furthermore, the results show that CDA does not seem to have an effect on planktonic bacteria, neither on the bacterial growth nor on the activity of the selected promoters. This suggests that the CDA effects are biofilm-dependent.Les biofilms sont des communautés de microorganismes adhérant à une surface et encastrées dans une substance polymérique produite par les cellules du système, dite matrice extracellulaire. Du fait de leur nature ubiquitaire, les biofilms colonisent de nombreux environnements et causent souvent de sérieux problèmes dans les secteurs de la santé et de l’industrie. La dispersion par ajout d’agent chimique est l’une des stratégies de lutte contre les biofilms. Un acide gras, l’acide cis-2-décénoique (CDA), semble être prometteur pour ce faire, grâce à l’étendue de son action dispersante sur les espèces et règnes du vivant. L’objectif de ce travail de thèse est d’investiguer les mécanismes de dispersion des biofilms de l’espèce bactérienne Escherichia coli (E. coli) par la molécule modèle CDA. Le CDA modifie-t-il les structures du biofilm ou induit-il une réponse génétique des bactéries lors de la dispersion ? Pour répondre à ces questions, la dispersion des biofilms d’E. coli a été étudiée in situ dans des chambres microfluidiques par microscopie confocale à balayage laser (CLSM). Des souches bactériennes spécifiques ont été construites par clonage de promoteurs d’intérêt en fusion transcriptionnelle avec un gène codant pour une protéine fluorescente verte. Les résultats confirment l’activité dispersante du CDA avec une réduction significative de la biomasse, de l’épaisseur moyenne et de l’aire de recouvrement par couche du biofilm. Un outil innovant d’analyse d’images CLSM a été développé en collaboration dans le but de déterminer les propriétés structurales du biofilm et l’intensité de fluorescence in situ du rapporteur étudié. Les résultats indiquent une augmentation de l’intensité moyenne de fluorescence des biofilms après dispersion avec le CDA, au niveau global en considérant tout le biofilm et au niveau local en considérant une segmentation du biofilm en microcolonies, ainsi qu’en profondeur. Ces résultats évoquent un changement d’expression génique des bactéries en présence de CDA. Par ailleurs, les résultats montrent que le CDA ne semble pas avoir d’effet en culture planctonique, ni sur la croissance bactérienne ni sur l’activité des promoteurs sélectionnés. Ceci suggère que les effets du CDA sont biofilm-dépendants
Path following control of unmanned quadrotor helicopter with obstacle avoidance capability
No full textInternational audienceThis paper proposes a new path following methodology combining with an obstacle avoidance scheme for unmanned quadrotor helicopter (UQH) capable of working in the cluttered and hazardous environments. A new cross-track error prediction based mechanism, where the cross-track error is estimated by utilizing the extend Kalman filter (EKF), is first developed for the path following scheme. Then, the UQH is equipped with obstacle avoidance capability employing a light-computational approach, the visibility graph algorithm. The priority of UQH is to switch to obstacles avoidance maneuvering in the presence of obstacles, and continue to execute the assigned mission after avoiding all hazardous objects blocking the desired path. The control system developed for attitude and position control of UQH is also introduced. Finally, extensive simulation studies on a nonlinear model of UQH with a series of dangerous scenarios are conducted to demonstrate the effectiveness of the proposed methodology
The learning curve effect on embolization of cerebral dural arteriovenous fistula single-center experience in 48 consecutive patients
No full textInternational audienc
Approximate transmission coefficients in heavy ion fusion
No full textInternational audienceIn this paper, we revisit the one-dimensional tunneling problem. We consider different approximations for the transmission through the Coulomb barrier in heavy ion collisions at near-barrier energies. First, we discuss approximations of the barrier shape by functional forms where the transmission coefficient is known analytically. Then, we consider Kemble’s approximation for the transmission coefficient. We show how this approximation can be extended to above-barrier energies by performing the analytical continuation of the radial coordinate to the complex plane. We investigate the validity of the different approximations considered in this paper by comparing their predictions for transmission coefficients and cross sections of three heavy ion systems with the corresponding quantum mechanical results
Explaining the Parameterized Wiener Filter with Alpha-Stable Processes
No full textInternational audienceThis paper introduces a new method for single-channel denoising that sheds new light on classical early developments on this topic that occurred in the 70’s and 80’s with Wiener filtering and spectral subtraction. Operating both in the short-time Fourier transform domain, these methods consist in estimating the power spectral density (PSD) of the noise without speech. Then, the clean speech signal is obtained by manipulating the corrupted time-frequency bins thanks to these noise PSD estimates. Theoretically grounded when using power spectra, these methods were subsequently generalized to magnitude spectra, or shown to yield better performance by weighting the PSDs in the so-called parameterized Wiener filter. Both these strategies were long considered ad-hoc. To the best of our knowledge, while we recently proposed an interpretation of magnitude processing, there is still no theoretical result that would justify the better performance of parameterized Wiener filters. Here, we show how the α-stable probabilistic model for waveforms naturally leads to these weighted filters and we provide a grounded and fast algorithm to enhance corrupted audio that compares favorably with classical denoising methods