Search

Background: Web-based surveys have become a new and popular method for collecting data, but only a few studies have directly compared postal and Web-based surveys among physicians, and none to our knowledge among general practitioners (GPs). Objective: Our aim is to compare two modes of survey delivery (postal and Web-based) in terms of participation rates, response times, and completeness of questionnaires in a study assessing GPs’ preventive practices. Methods: This randomized study was conducted in Western Switzerland (Geneva and Vaud) and in France (Alsace and Pays de la Loire) in 2015. A random selection of community-based GPs (1000 GPs in Switzerland and 2400 GPs in France) were randomly allocated to receive a questionnaire about preventive care activities either by post (n=700 in Switzerland, n=400 in France) or by email (n=300 in Switzerland, n=2000 in France). Reminder messages were sent once in the postal group and twice in the Web-based group. Any GPs practicing only complementary and alternative medicine were excluded from the study. Results: Among the 3400 contacted GPs, 764 (22.47%, 95% CI 21.07%-23.87%) returned the questionnaire. Compared to the postal group, the participation rate in the Web-based group was more than four times lower (246/2300, 10.70% vs 518/1100, 47.09%, P

In this paper, we propose a method for coarse camera pose computation which is robust to viewing conditions and does not require a detailed model of the scene. This method meets the growing need of easy deployment of robotics or augmented reality applications in any environments, especially those for which no accurate 3D model nor huge amount of ground truth data are available. It exploits the ability of deep learning techniques to reliably detect objects regardless of viewing conditions. Previous works have also shown that abstracting the geometry of a scene of objects by an ellipsoid cloud allows to compute the camera pose accurately enough for various application needs. Though promising, these approaches use the ellipses fitted to the detection bounding boxes as an approximation of the imaged objects. In this paper, we go one step further and propose a learning-based method which detects improved elliptic approximations of objects which are coherent with the 3D ellipsoid in terms of perspective projection. Experiments prove that the accuracy of the computed pose significantly increases thanks to our method and is more robust to the variability of the boundaries of the detection boxes. This is achieved with very little effort in terms of training data acquisition -- a few hundred calibrated images of which only three need manual object annotation. Code and models are released at https://github.com/zinsmatt/3D-Aware-Ellipses-for-Visual-Localization., Comment: Presented at 3DV 2020. Code and models released at https://github.com/zinsmatt/3D-Aware-Ellipses-for-Visual-Localization

International audience; We present the use of a new computationaly efficient 3D physics model for the simulation of cells in a virtual aquatic world. In this model, cells can freely assemble and disconnect along the simulation without any separation between the development and evaluation stages, as is the case in most evo-devo models which only consider one cell cluster. While allowing for the discovery of interesting behaviors through the addition of new degrees of freedom, this 3D center-based physics engine and its associated virtual world also come with their drawbacks when applied to evolutionnary experiments: larger search space and numerous local optima. In this paper, we have designed an experiment in which cells must learn to survive by keeping their genome alive as long as possible in a demanding world. No morphology or strategy is explicitly enforced; the only objective the cells have to optimize is the survival time of the organism they build. We show that a novelty metric, adapted to our evo-devo matter, dramatically improves the outcome of the evolutionary runs. This paper also details some of the developmental strategies the evolved multicellular organisms have found in order to survive.

National audience; Research contributions to improve interactive systems reliability as, for now, mainly focused towards fault occurrence prevention by removing software bugs at development time. However, Interactive Systems complexity is so high that whatever efforts are deployed at development time, faults and failures occur at operation time. Root causes of such failures may be due to transient hardware faults or (when systems are used in high atmosphere) may be so called "natural faults" triggered by alpha particles in processors or neutrons from cosmic radiations. This paper proposes an exhaustive identification of faults to be handled in order to improve interactive systems reliability. As currently no research has been carried out in the field of interactive systems to detect and remove natural faults, this paper proposes a software architecture providing fault-tolerant mechanisms dedicated to interactive systems. More precisely, the paper how such architecture addresses the various component of interactive applications namely widgets, user application and window manager. These concepts are demonstrated through a case study from the domain of interactive cockpits of large civil aircrafts. \; La recherche pour améliorer la fiabilité des systèmes interactifs s’est, pour l’instant, principalement dirigée vers la prévention d’introduction de fautes par la suppression des bugs lors du développement. Cependant, la complexité des systèmes interactifs est telle que, quels que soient ces efforts, des défaillances apparaissent lors de leur utilisation. Les causes de telles défaillances peuvent être dues à des pannes matérielles intermittentes ou (quand ces systèmes sont utilisés en haute altitude (avions, véhicules spatiaux …) être déclenchées par des fautes naturelles dues aux particules alpha dans les processeurs ou aux neutrons issus des radiations cosmiques. Cet article propose l’identification exhaustive des problématiques se posant pour améliorer la fiabilité des systèmes interactifs en prenant en compte à la fois les erreurs faites dans les phases de développement et les fautes qui peuvent se produire lors de leur utilisation. Du fait qu’aucune recherche n’a été menée à ce jour pour détecter et éliminer les fautes naturelles, l’article propose aussi une architecture logicielle pour intégrer des mécanismes de tolérance aux fautes dans les systèmes interactifs. L’article présente en particulier comment cette architecture couvre les différents composants d’un système interactif incluant les widgets, le gestionnaire de fenêtres et l’application interactive. Ces concepts sont mis en œuvre sur une application interactive de cockpits d’avions civils.

National audience; Real-time adaptive production control in the flexible manufacturing cell (FMC) is a complex issue that needs to be addressed to realize good performance and high productivity. In this paper, we have considered a support vector machine (SVM)-based simulation approach to resolve a production control problem in an FMC that operates in a dynamic environment. A SVM-based simulation approach chooses the most relevant scheduling rule out of several predefined ones on the basis of the current states of the system. This paper examines and compares the performance of the SVM-based simulation approach with the competent scheduling rules under two different operational environments which are characterized by the uncertainty of demand. We have also developed a Visual Basic-based simulation approach for scheduling of component parts in the context of FMC under different situations. The SVM methodology to control the production offers better performance than the single-rule-based production control system.

International audience; Given the maturity of Internet standards, inter-organizational workflow is expected to be deployed in environments that are more dynamic and open than before. This paper addresses Inter Organizational Workflow (IOW) coordination in such a context, mainly investigating autonomic coordination managed at run-time. It is based on the idea that an agent-based approach is suitable to deal with this issue. More precisely, this paper introduces a framework for dynamic IOW in which involved processes are encapsulated into agents, called Process Agents (PA) in order to give them the capability to autonomously decide with whom, when and how to cooperate, and in which involved processes can access protocol components for their coordination needs. Our approach is based on the capability of PAs in playing different coordination protocols in order to take part in new business opportunities. This solution has numerous advantages. First, it provides extendable and reusable coordination components. Then, it supports run-time protocol integration. Finally, it eases openness since it imposes very few constraints.

International audience; Multiple-Input/Multiple-Output (MIMO) techniques have recently become an important research field for enhancing the performance of in-home Power Line Communication (PLC) systems by exploiting the additional Protective Earth wire. The development of such systems requires an accurate description of the channel noise. In this paper we have presented a model for PLC background noise based on an extensive set of measurements. We have adopted the framework of multivariate time series to model the PLC background noise.This paper employs the Vector Autoregressive (VAR) modeling technique to extract noise model parameters from the measured noise. We have verified the accuracy of the noise model by comparing time and frequency domain correlation of measured and modeled noises.

International audience; This paper reports an experience feedback about a Master-2 and Engineering-School level training in HCI based on the transfer of knowledge and technology from research and industry. We emphasize the importance of training students to promising research areas such as user interface plasticity and to recent technologies for developing mobile media and MS surface table applications. The whole training enhances user-centered methodsto encourage students to focus on the use of applications.; Cet article présente un retour d'expérience sur une formation en IHM de niveau Master 2 et École d'ingénieurs reposant sur le transfert de savoirs et de technologies issus de la recherche et de l'industrie. Nous mettons l'accent sur l'importance de former les étudiants à des domaines de recherche prometteurs tels que la plasticité des IHM et à des technologies récentes permettant le développement d'applications sur supports mobiles et table MS Surface. L'ensemble de la formation valorise les méthodes centrées utilisateurs afin d'inciter les étudiants à privilégier l'usage des applications. ABSTRACT This paper reports an experience feedback about a Master-2 and Engineering-School level training in HCI based on the transfer of knowledge and technology from research and industry. We emphasize the importance of training students to promising research areas such as user interface plasticity and to recent technologies for developing mobile media and MS surface table applications. The whole training enhances user-centered methods to encourage students to focus on the use of applications.

International audience; Several separate displays are used by Air Traffic Controllers, such as radar view, flight lists view or paper strips. In order to link the information between these views and keep focus on a subset of flights, controllers are required to do visual operations (eye gaze, analysis of visual properties etc.). This process can be disruptive when traffic increases and when visualizations display large amounts of objects. In this paper we propose the use of animated transitions to replace the visual paths controllers take. We discuss this technique and show results of a predictive evaluation that suggests an improvement in users' performance.

In this paper, the duality in differential form is developed between a 3D primal surface and its dual manifold formed by the surface's tangent planes, that is, each tangent plane of the primal surface is represented as a four-dimensional vector that constitutes a point on the dual manifold. The iterated dual theorem shows that each tangent plane of the dual manifold corresponds to a point on the original 3D surface, that is, the "dual" of the "dual" goes back to the "primal." This theorem can be directly used to reconstruct 3D surface from image edges by estimating the dual manifold from these edges. In this paper, we further develop the work in our original conference papers resulting in the robust differential dual operator. We argue that the operator makes good use of the information available in the image data by using both points of intensity discontinuity and their edge directions; we provide a simple physical interpretation of what the abstract algorithm is actually estimating and why it makes sense in terms of estimation accuracy; our algorithm operates on all edges in the images, including silhouette edges, self occlusion edges, and texture edges, without distinguishing their types (thus, resulting in improved accuracy and handling locally concave surface estimation if texture edges are present); the algorithm automatically handles various degeneracies; and the algorithm incorporates new methodologies for implementing the required operations such as appropriately relating edges in pairs of images, evaluating and using the algorithm's sensitivity to noise to determine the accuracy of an estimated 3D point. Experiments with both synthetic and real images demonstrate that the operator is accurate, robust to degeneracies and noise, and general for reconstructing free-form objects from occluding edges and texture edges detected in calibrated images or video sequences.

4 pages, démonstrations; National audience; In this paper, we discuss a choice of props for a dedicated task: selecting a cutting line from a top map. We present GeoTUI, a tabletop and a Tangible User Interface intended to geosciences. Several props have been evaluated for both usability and task performance. We begin with an analysis of the advantages of addressing a specific domain in this kind of study.; Nous nous intéressons à la sélection d'une ligne de coupe dans un modèle 3D. Nous nous situons donc dans le pa-radigme des interfaces utilisateurs 3D (3DUI). Dans ce contexte, il est intéressant pour adresser un problème gé-néral d'expérimenter sur des applications métiers complexes porteuses de contraintes et d'exigences, ici les géosciences. Dans le cadre de l'interface proposée, table interactive et interface tangible, nous étudions les diffé-rentes métaphores d'interaction possibles et déterminons le meilleur interacteur pour la tâche ciblée. ABSTRACT In this paper, we discuss a choice of props for a dedicated task: selecting a cutting line from a top map. We present GeoTUI, a tabletop and a Tangible User Interface intended to geosciences. Several props have been evaluated for both usability and task performance. We begin with an analysis of the advantages of addressing a specific domain in this kind of study.

This paper reviews the empirical and theoretical literature on economic growth to examine how the four components of the climate change bill, namely mitigation, proactive (ex ante) adaptation, reactive (ex post) adaptation, and ultimate damages of climate change affect growth, especially in developing countries. The authors consider successively the Cass-Koopmans growth model and three major strands of the subsequent literature on growth: with multiple sectors, with rigidities, and with increasing returns. The paper finds that although the growth literature rarely addresses climate change per se, some issues discussed in the growth literature are directly relevant for climate change analysis. Notably, destruction of production factors, or decrease in factor productivity may strongly affect long-run equilibrium growth even in one-sector neoclassical growth models; climatic shocks have had large impacts on growth in developing countries because of rigidities; and the introducing increasing returns has a major impact on growth dynamics, in particular through induced technical change, poverty traps, or lock-ins. Among the most important gaps identified in the literature are lack of understanding of the channels by which shocks affect economic growth, lack of understanding of lock-ins, heavy reliance of numerical models assessing climate policies on neoclassical-type growth frameworks, and frequent use of an inappropriate

International audience; In this paper, we discuss the control and suppression of spurious resonances commonly encountered with distributed bandpass filters. The basic idea consists of introducinglow-pass structures within bandpass topologies. By adjusting low-pass filter cutoff frequencies, harmonic resonances are attenuated, while maintaining in-band performances. In addition, transmission losses may be reduced as the insertion technique leads to optimum designs in terms of overall size. The approach described here is based upon the combination of classical synthesis techniques and optimization proceduresprovided by conventional computer-aided-design tools. Experimental results are obtained in the case of /spl lambda//sub g//4 shunt-stub filters implemented in classical semilumped low-pass architectures. Then, we investigate alternative integration technologies and techniques to improve the out-of-band rejection over very wide operating bandwidth. To overcome some design limitations, i.e., workable characteristicimpedance value, we propose and validate a multilayer solution. Finally, new low-pass topologies are suggested to improve low-pass filter band rejection.; In this paper, we discuss the control and suppression of spurious resonances commonly encountered with distributed bandpass filters. The basic idea consists of introducinglow-pass structures within bandpass topologies. By adjusting low-pass filter cutoff frequencies, harmonic resonances are attenuated, while maintaining in-band performances. In addition, transmission losses may be reduced as the insertion technique leads to optimum designs in terms of overall size. The approach described here is based upon the combination of classical synthesis techniques and optimization proceduresprovided by conventional computer-aided-design tools. Experimental results are obtained in the case of /spl lambda//sub g//4 shunt-stub filters implemented in classical semilumped low-pass architectures. Then, we investigate alternative integration technologies and techniques to improve the out-of-band rejection over very wide operating bandwidth. To overcome some design limitations, i.e., workable characteristicimpedance value, we propose and validate a multilayer solution. Finally, new low-pass topologies are suggested to improve low-pass filter band rejection.

International audience; In recent years, metasurfaces have become a rapidly growing domain of research in several fields of engineering and applied physics due to their ability to manipulate both phase and amplitude of electromagnetic fields. These artificial 2D-materials, usually composed of metallic elements printed on dielectric substrates, have the advantages of being low profile, lightweight as well as easy to fabricate and integrate with standard circuit technologies. In this context, this paper reviews the latest progress in metasurface antenna design, where metasurfaces are used to miniaturize the profile, increase the bandwidth, and control the radiation pattern in the near- and far-field regions.; Ces dernières années, la thématique des métasurfaces est devenue un sujet de recherche en pleine expansion dans plusieurs domaines de l’ingénierie et de la physique appliquée, en raison de leur capacité à manipuler à la fois la phase et l’amplitude des champs électromagnétiques. Ces matériaux artificiels bi-dimensionnels, généralement composés d’éléments métalliques imprimés sur des substrats diélectriques, ont l’avantage d’être de très faible épaisseur, légers et faciles à fabriquer et à intégrer avec les circuits imprimés. Cet article passe en revue les dernières avancées dans la conception d’antennes à métasurface, où les métasurfaces sont utilisées pour minimiser l’épaisseur, augmenter la bande passante et contrôler le diagramme de rayonnement en champ proche et en champ lointain.

The placement of Virtual Network Function - Forwarding Graphs (VNF-FGs) is one of the basic operations in the networks of the future. Being NP-hard, several heuristics and metaheuristics have been proposed. However, these approaches are inefficient due to the need to recalculate the solution at each service placement. In this paper, we adapt one of the most advanced approaches in Deep Reinforcement Learning (DRL), in order to improve exploration by generalizing the neural network calculating action values. We also propose an evolutionary algorithm to evolve these neural networks in order to discover better ones, which also avoids getting stuck in local minima. In order to avoid going through the almost innumerable number of infeasible solutions, we propose a heuristic, which combined with our DRL, makes it possible to guarantee the feasibility of the solutions and therefore to make the placement much more efficient. The simulation results we obtained confirm the quality of the solutions obtained as well as the superiority of the proposed solution over the existing one.

International audience; Most infectious diseases in humans originate from animals. In this paper, we explore the role of animal farming and meat consumption in the emergence and amplification of infectious diseases. First, we discuss how meat production increases epidemic risks, either directly through increased contact with wild and farmed animals or indirectly through its impact on the environment (e.g., biodiversity loss, water use, climate change). Traditional food systems such as bushmeat and backyard farming increase the risks of disease transmission from wild animals, while intensive farming amplifies the impact of the disease due to the high density, genetic proximity, increased immunodeficiency, and live transport of farmed animals. Second, we describe the various direct and indirect costs of animal-based infectious diseases, and in particular, how these diseases can negatively impact the economy and the environment. Last, we discuss policies to reduce the social costs of infectious diseases. While existing regulatory frameworks such as the "One Health" approach focus on increasing farms' biosecurity and emergency preparedness, we emphasize the need to better align stakeholders' incentives and to reduce meat consumption. We discuss in particular the implementation of a "zoonotic" Pigouvian tax, and innovations such as insect-based food or cultured meat.

In the fast fashion industry, high delivery frequencies and low lead times are key factors of market competitiveness. To this goal, many companies are evaluating the possibility of opening urban satellites close to retail stores. Urban satellites can assure a number of daily replenishments larger than one at the retail stores. However, opening urban satellites requires expensive capital expenditures and can increase transportation costs. In this paper, we investigate the impact of urban satellites on the service level, inventory and transportation costs of fast fashion supply chains. Discrete event simulation is used to assess the value that urban satellites can provide to fast fashion supply chains. The application to an Italian retailer case study reveals that the increased transportation and storage costs may be compensated by increased sales as a result of a wider product assortment at the retail stores. The case study simulation results are proposed as possible lessons for other fast fashion last mile distribution systems.

International audience; Decreasing electricity consumption is a major challenge of our society. Eco-feedback methods allow users to get information about their electricity consumption to reduce it. However it is still difficult to determine what are the actions that impact the consumption in practice. In this paper we suggest to apply a What if approach to eco-feedback in a household context. We deploy the Activelec system in personal housings, which allows to apply virtual modifications in appliances usage and to evaluate the savings realized. The results of our experimentation show that participants appreciated the interaction method based on the What if. It allowed them to find and to evaluate efficient modifications in their appliances usage, and several have been applied in practice by the participants. This experimentation shows that the What if paradigm is a potential way for eco-feedback technologies.; Réduire la consommation d’électricité est un enjeu majeur de notre société. Les méthodes eco-feedback permettent aux utilisateurs d’obtenir un retour sur leur consommation d’électricité afin de la diminuer. Toutefois, il est toujours difficile de déterminer concrètement quelles actions impactent la consommation. Dans cet article, nous proposons d’appliquer une méthode What if à l’eco-feedback en contexte domestique. Nous déployons le système Activelec dans des logements personnels, qui permet d’appliquer des changements virtuels dans l’utilisation des appareils et d’évaluer les économies réalisées. Les résultats de notre expérimentation montrent que les participants ont apprécié la méthode d’interaction basée sur le What if. Celle-ci leur a permis de trouver et d’évaluer des modifications efficaces dans l’utilisation de leurs appareils, et certaines ont été appliquées en pratique par les participants. Cette expérimentation montre que le paradigme What if est une piste potentielle pour les technologies eco-feedback.

International audience; The development of a network centered life has increased overall data rates in core networks. Thus, data centers face the challenge to provide always more services at higher data rates while reacting quickly to complex failures and more powerful attacks thanks to efficient network forensics. Moreover, Software-Defined Networking (SDN) becomes a standard which offers agility but also requires forensic devices able to handle multiple configurations. Although conventional software probes are programmable and thus agile, they cannot support high data rate packet processing any more. Probes could benefit from Application Specific Integrated Circuits (ASIC) to cope with high data rates, but ASICs development time of many months makes them unable to satisfy agility requirements. With reconfiguration ability and high throughput processing without packet loss, Field Programmable Gate Arrays (FPGA) are the key technology chosen by some companies, such as Microsoft, Amazon and OVH, to be integrated into smart Network Interface Cards (NIC). Nevertheless, while high performance criteria is fulfilled, current FPGA probes benefit from an agility still limited to their conventional firmware upgrades which require proprietary tools and hardware-design time and knowledge. This paper proposes the first solution to offer FPGA probes with runtime agility thanks to a flexible packet parser which can be parameterized continuously by a software, endorsing complex tasks and SDN control. This allows a live adaptation of protocol processings from computer host alongside handling packets at line rate without data loss. The proposed parser is open-source and easily usable by network engineers through a Python software API. Benchmark results illustrate the performance of the agile high-level probe implemented on a NetFPGA SUME board, with XC7VX690T FPGA. 60 millions of 64-byte packets are counted based on features provided at runtime. These are selected by the software part, allowing the detection of different volumetric attacks within a few tens of microseconds. This represents a 40 Gb/s traffic of smallest Ethernet packets with no packet loss. With adequate boards, the generic design of the probe offers 160 Gb/s data rates and beyond on modern hardware, assuring probe scalability.

International audience; The RFID (Radio Frequency IDentification) technology is a well-known wireless application for traceability, logistics, and access control. It became ubiquitous in industry and our daily life (ticketing, payment, passports, car keys, etc.). RFID is nowadays a standardized technology; its inherent advantages, which are unitary, identification, wireless communication, and low cost of tags, provide it with decisive practical benefits that drive new developments in terms of concepts and applications. This trend is largely confirmed by the market forecast, but also by its implementation in the area of health (smart hospital), assistance to persons, anti-counterfeiting, as well as by its perspective in terms of new paradigms for distributed ambient intelligence and the Internet of Things. The first part of this paper briefly reviews the fundamental concepts of the RFID technology, and shows its link with the radio science. A state of the art including the presentation of current performance and developments is also summarized. The second part illustrates the impact of RFID to the service of our society with a focus of applications in the field of autonomy and handicap. Finally, the last part highlights a panorama of perspectives and the future directions of RFID applications dedicated to the service of Humanity.; La RFID (radio par identification) est aujourd'hui une technologie sans fil bien connue pour ses applications en traçabilité, logistique et contrôle d'accès. Elle est devenue omniprésente dans l'industrie et notre vie de tous les jours (tickets de transport, systèmes de paiement, passeports, clés de voiture, etc.). Technologie standardisée, ses avantages inhérents (identification unitaire et télé-alimentation) et le coût modeste des tags lui procurent des avantages pratiques déterminants qui impulsent de nouvelles évolutions, aussi bien applicatives que conceptuelles. Cette tendance est largement démontrée, que ce soit par les projections économiques en termes de croissance et de marchés, son succès déjà actuel dans les secteurs de la santé ( « Intelligent Hospital ») et de l'assistance aux personnes, ses aptitudes dédiées aux applications d'anti-contrefaçons, ou encore ses promesses pour les paradigmes naissant d'intelligence ambiante distribuée et d'Internet des objets. Le premier volet de ce papier rappelle brièvement les fondamentaux conceptuels de la RFID et leur lien avec les radiosciences. L'état de l'art, les performances et les développements actuels sont résumés. Dans un deuxième volet, l'impact de la RFID au service de notre société avec un focus d'applications autour de l'autonomie et du handicap est présenté. Le dernier volet dresse un panorama des perspectives et tendances futures, annonciateurs de l'évolution grandissante des applications visées par la RFID et de la place qu'elle prendra au service de l'humanité.

International audience; Genetic Regulatory Networks (GRNs) implementations have a high degree of variability in their details. Parameters, encoding methods, and dynamics formulas all differ in the literature, and some GRN implementations have a high degree of model complexity. In this paper, we present a comparative study of different implementations of a GRN and introduce new variants for comparison. We use a modified Genetic Algorithm (GA) to evaluate GRN performance on a number of common benchmark tasks, with a focus on real-time control problems. We propose an encoding scheme and set of dynamics equations that simplifies implementation and evaluate the evolutionary fitness of this proposed method. Lastly, we use the comparative modifications study to demonstrate overall enhancements for GRN models.

International audience; In desktop 3D modeling applications, object manipulation relies on the use of standard transformation widgets. However, these widgets are less efficient on touchscreens due to the low accuracy of touch inputs, and also to the fingertip occlusion issue. In this paper, we propose two unimanual constrained manipulation techniques on TabletPCs. Based on finger identification, our techniques map the index, middle and ring fingers of the dominant hand to the X, Y and Z axes of the coordinate system. After registering the axis-fingers mapping on the screen, users can perform different chording gestures to trigger axis-, plane-constrained or uniform manipulations. We have conducted a user study to examine the learnability and usability of the proposed gestures. The results indicate that these gestures can be memorized quickly after a short training period. Users found some gestures to be easy to use and comfortable while others require additional investigations. These findings permits to give recommendations for designing a unimanual constrained manipulation technique that can be used efficiently in a 3D modeling application on TabletPCs.; Dans les applications de modélisation 3D sur PC, la manipulation avec contraintes d'objets repose sur l’utilisation des widgets de transformation 3D. Cependant, ces widgets sont moins efficaces pour une utilisation sur des écrans tactiles en raison de la faible précision des dispositifs d’entrée et des problèmes d'occultation. Dans ce papier, deux nouvelles techniques uni-manuelles de manipulation 3D sur TabletPC sont proposées. Basées sur l’identification des doigts, nos deux techniques associent l'index, le majeur et l'annulaire de la main dominante aux axes x, y et z du système de coordonnées. Après l’enregistrement de cette association axe-doigts, les utilisateurs peuvent effectuer différents gestes d’accords pour des manipulations avec contraintes sur les axes, sur les plans et des manipulations uniformes. Nous avons mené une étude préliminaire pour examiner l'apprenabilité et l’utilisabilité des gestes proposées. Les résultats indiquent que ces derniers peuvent être mémorisés rapidement. Certains gestes ont été jugés confortables et faciles à utiliser par les utilisateurs alors que d’autres nécessitent davantage d’investigations. Ces résultats permettent de donner des recommandations quant à la conception d’une technique uni-manuelle de manipulation avec contraintes qui peut être utilisée efficacement pour la modélisation 3D sur TabletPC.

International audience; Noncooperative underwater acoustic (UWA) communication systems are prone to interfere with each other since the limited resource offered by the channel is not regulated by any standard. Mutual inteferences can significantly degrade the performances of such systems and it is necessary to find policies allowing UWA devices to access the same physical resource. In this paper, we consider noncooperative UWA OFDM systems competing to access the same portion of the spectrum. We show that an efficient decentralized power allocation strategy can be achieved when all the communication links apply a waterfilling policy only based on little knowledge about their environment. Numerical simulations performed with real UWA channels sounded at-sea demonstrate the relevance of our approach.

International audience; In this paper, we show how a dangerousness metric can be used to modify the input of a gene regulatory network when plugged to a virtual car. In the context of the 2015 Simulated Car Racing Championship organized during GECCO 2015, we have developed a new cartography methodology able to inform the controller of the car about the incoming complexity of the track: turns (slipperiness, angle, etc.) and bumps. We show how this dangerousness metric improves the results of our controller and outperforms other approaches on the tracks used in the competition.

International audience; Knowledge-based decision support systems (KBDSS) have evolved greatly over the last few decades. The key technologies underpinning the development of KBDSS can be classified into three categories: technologies for knowledge modelling and representation, technologies for reasoning and inference and web-based technologies. In the meantime, service systems have emerged and become increasingly important to value adding activities in the current knowledge economy. This paper provides a review on the recent advances in the three types of technologies, as well as the main application domains of KBDSS as service systems. Based on the examination of literature, future research directions are recommended for the development of KBDSS in general and in particular to support decision-making in service industry.

The present paper describes the energy analysis of a regenerative vapour power system. The regenerative steam turbines based on the Rankine cycle and comprised of vapour extractions have been used industrially since the beginning of the 20th century, particularly regarding the processes of electrical production. After having performed worked in the first stages of the turbine, part of the vapour is directed toward a regenerative exchanger and heats feedwater coming from the condenser. This process is known as regeneration, and the heat exchanger where the heat is transferred from steam is called a regenerator (or a feedwater heater). The profit in the output brought by regenerative rakings is primarily enabled by the lack of exchange of the tapped vapour reheating water with the low-temperature reservoir. The economic optimum is often fixed at seven extractions. One knows the Carnot relation, which is the best possible theoretical yield of a dual-temperature cycle; in a Carnot cycle, one makes the assumption that both compressions and expansions are isentropic. This article studies an ideal theoretical machine comprised of vapour extractions in which each cycle partial of tapped vapour obeys these same compressions and isentropic expansions., Les turbines à vapeur basées sur les cycles de Hirn et de Rankine comportant des soutirages de vapeur sont utilisées industriellement depuis le début du XX siècle. C’est notamment le cas des process de production d’électricité.Après avoir travaillé dans les premiers étages de la turbine, une partie de la vapeur est dirigée vers un échangeur et réchauffe l’eau provenant du condenseur.Le gain en rendement apporté par les soutirages régénératifs est essentiellement du au fait que la vapeur soutirée réchauffe l’eau et n‘échange pas en pure perte avec la source froide. L’optimum économique est souvent fixé à 7 soutirages.On connaît la relation de Carnot qui est le meilleur rendement théorique possible d’un cycle bitherme dans lequel on fait l’hypothèse que les compressions et les détentes sont isentropiques.Cet article étudie une machine théorique idéale comportant des soutirages de vapeur dans laquelle chaque cycle partiel de vapeur soutirée obéit à ces mêmes hypothèses de compressions et détentes isentropiques.

International audience; This paper discloses an Analogiser able to carry out digital to analogue conversion of the optically digitised Radio-over-Fibre signals. The Analogiser comprises many interconnected optical circuits based on the Sagnac interferometric rings with an inserted semiconductor optical amplifier. Numerical simulation results are shown for 2.5 GHz sampling rate and 4-bit resolution. The designed circuits are compact, thus enabling optical integration and require optical peak power control in the ~mW range.

cote interne IRCAM: Mitsufuji14a; None / None; National audience; This paper proposes a new method to enhance the performance of non-negative tensor factorization (NTF), one of the most prevalent source separation techniques nowadays. The enhancement is mainly achieved by introducing weights on bin-wise NTF cost functions, which differentiates NTF target components from other components so that the target should be approximated more precisely than others. Assuming sources are distributed sparsely in a 2-D sound field, the target components approximating a target source are exclusively selected by a user, or from accompanying images by means of providing a spatial cue to an NTF framework. The spatial cue is given in a similar format to the well-known binaural feature, inter-channel level difference (IID). This helps incorporate the spatial cue into the system, since the similar features of this format can be easily calculated from every spectrogram bin. The weighting functions are designed taking into account the distance between the spatial cue and the calculated features. Namely, the largest values are assigned to the spectrogram bins where the features present the highest similarity to the spatial cue, and the value decreases in proportion to the distance between them. The method is evaluated in terms of separation quality, comparing the proposed algorithm to the conventional NTF technique, PARAFAC-NTF, as well as other source separation techniques. The evaluation results measured by the metric signal-to-distortion ratio (SDR), signal-to-interference ratio (SIR), and signal-to-artifact ratio (SAR) demonstrate the effectiveness of the new method, improved primarily by the weighting function and the initialization based on IID, while demonstrating a decrease in computational costs, a significant problem with NTF.

International audience; Evolution in the context of use requires evolutions in the user interfaces even when they are currently used by operators. User Centered Development promotes reactive answers to this kind of evolutions either by software evolutions through iterative development approaches or at runtime by providing additional information to the operators such as contextual help for instance. This paper proposes a model-based approach to support proactive management of context of use evolutions. By proactive management we mean mechanisms in place to plan and implement evolutions and adaptations of the entire user interface (including behaviour) in a generic way. The approach proposed handles both concentration and distribution of user interfaces requiring both fusion of information into a single UI or fission of information into several ones. This generic model-based approach is exemplified on a safety critical system from space domain. It presents how the new user interfaces can be generated at runtime to provide a new user interface gathering in a single place all the information required to perform the task. These user interfaces have to be generated at runtime as new procedures (i.e. sequences of operations to be executed in a semi-autonomous way) can be defined by operators at any time in order to react to adverse events and to keep the space system in operation. Such contextual, activity-related user interfaces complement the original user interfaces designed for operating the command and control system. The resulting user interface thus corresponds to a distribution of user interfaces in a focus+context way improving usability by increasing both efficiency and effectiveness.

National audience; Recently government agencies have started to utilize innovative contracting methods that provide incentives for improving construction quality. These emerging contracting methods place an enormous pressure on the contractors to improve construction quality. For a general contractor, which subcontracts most tasks of a project and invites a number of bids, choosing an appropriate bid which satisfies the time, cost and quality of construction project is complex and challenging. To solve this problem involving conflicting objectives, a fuzzy clustering-based genetic algorithm (FCGA) approach is proposed in this paper. A case study of highway construction is used to demonstrate the applicability of the proposed approach. A comparative study is conducted over three test cases involving varying dimensions and complexities to test performance of the proposed FCGA against existing approaches. Results reveal that the FCGA is capable of generating better Pareto front than other existing approaches.

This paper presents the latest improvements on AudioPrint: the IRCAM audio fingerprint system. Cosine filters are introduced in the short-term spectral analysis, in order to compensate the effect of pitch shifting, and a simple solution is proposed for the determination of the frame positions, robust to audio degradations, with nearly no additional cost. We then show that both contributions significantly improve the Audio-Print system, with evaluations both on a free corpus, made publicly available, and a real-world corpus of broadcast radio streams.

Novelty-based segmentation of audio signals has proven good performances for the estimation of boundaries of structural sections within music pieces. However, boundaries are detected only if structural sections satisfy the condition of sufficient acoustic inner-homogeneity. While this constraint is very restrictive and not representative of all musical contents, we propose in this paper to extend the detection of acoustic novelty to transitions between homogeneous and non-homogeneous sections and vice versa. Moreover, the length of the considered sections for the boundary detection is crucial, we also introduce a multi-scale novelty approach that allows to capture boundaries between sections of different temporal scales in a same segmentation. Evaluation of the combination of these two methods proves convincing results for temporal segmentation of music pieces. Embedding the algorithm in a music structure segmentation system, we show that performances can be consistently improved for this task.

In this paper, we introduce a new approach to music structure segmentation that is based on the joint estimation of structural segments, keys and chords in one probabilistic framework. More precisely, the boundaries of a structure segment are determined by detecting key changes and by utilizing the difference in prior probability of chord transitions according to their position in a structural segment. In contrast to many of the recent approaches to structural segmentation, this system does not work with self-similarity matrices, although it has been designed to integrate this kind of approach into the framework at a later stage. However, just the current version of the system, using only the estimated harmony, is already producing encouraging results, especially with respect to the precise localization of the boundaries.

International audience; Metamorphic robots are robots that can change their shape by reorganizing the connectivity of their modules to adapt to new environments, perform new tasks, or recover from damages. In this paper we present a decentralized method for structural evolving of a class of lattice-based simulated metamorphic robots in a static environment. These robots are considered as a set of crystalline (compressible) modules that are able to connect or disconnect one from each another or even exchange information and energy with the neighbor modules in order to form various structures/patterns dynamically. Our approach is splitted in two layers: in the first layer a genetic algorithm is used to generate a number of well suited target configurations based on current information perceived from environment, while in the second layer a PacMan-like algorithm is used to make a plan for modules movement to transform the robot from its current pattern to the target pattern emerged in first layer.

International audience; This paper describes the first step of a research project with the aim of predicting students' performance during an online curriculum on a LMS and keeping them from falling behind. Our research project aims to use data mining, machine learning and artificial intelligence methods for monitoring students in e-learning trainings. This project takes the shape of a partnership between computer science / artificial intelligence researchers and an IT firm specialized in e-learning software. We wish to create a system that will gather and process all data related to a particular e-learning course. To make monitoring easier, we will provide reliable statistics, behaviour groups and predicted results as a basis for an intelligent virtual tutor using the mentioned methods. This system will be described in this article. In this step of the project, we are clustering students by mining Moodle log data. A first objective is to define relevant clustering features. We will describe and evaluate our proposal. A second objective is to determine if our students show different learning behaviours. We will experiment whether there is an overall ideal number of clusters and whether the clusters show mostly qualitative or quantitative differences. Experiments in clustering were carried out using real data obtained from various courses dispensed by a partner institute using a Moodle platform. We have compared several classic clustering algorithms on several group of students using our defined features and analysed the meaning of the clusters they produced.

National audience; Multi-touch interaction requires a trade-off between users' desires and capabilities, and gesture recognition constraints. Current approaches to that problem lack flexibility. The number of fingers used for a gesture usually plays a key part in the recognition process, for example. In this paper, we propose the use of pseudo-rigid movements to increase the flexibility of this process. We show how these movements can be determined in real time from the contact information usually available. We explain how they allow to free the recognition process from the number of fingers used and to move towards multi movement gestures, independent or coordinated. Finally, we present an interaction technique that takes advantage of this increased flexibility.

International audience; Internet connectivity in the ITS context is a flourishing demand that has to be covered by efficient information and communication technologies. Thanks to the provision of this connectivity, not only end users will profit from communication services, but also services for controlling the operation of the vehicle will benefit from the Internet connectivity. Services related to the operation and control of the vehicles exchange sensitive data, so strong security properties have to be ensured for this type of services. In addition, because of the privacy concerns related to the end users, it is desired to provide this kind of services with an adequate security level. From the communication point of view, a vehicle can be regarded as a mobile network where nodes onboard obtain continuous and optimal Internet connectivity, so, its mobility has to be managed. In the same way, network mobility management protocols should not only avoid security leaks, but also they have to ensure an adequate security level. It is needless to say that the introduction of security properties cannot render not fulfilling service performance requirements. In fact, the trade-off between security and application performance is a must. ITS standardisation bodies have adopted the NEtwork MObility Basic Support (NEMO BS) protocol to manage the mobility of networks. However, it still presents shortcomings like lack of security support and routing problems, which leads to a bad performance. One of the most promising design approaches is to consider a base mobility management protocol that provides out of the box security and route optimisation support like the Host Identity Protocol (HIP). Different solutions based on HIP can be found to solve network mobility in the literature, but none of these solutions aim at solving securely and efficiently network mobility management. That is, the provision of security properties to the network mobility management itself and to the end-to-end data communications while not increasing the signalling overhead and the manageability level remains unsolved. In this paper, we present the NeMHIP. NeMHIP is a secure and efficient network mobility management protocol which is based on HIP. In order to demonstrate its feasibility, we have carried out a study by means of analytical modelling to assess the performance of user applications with stringent QoS requirements like VoIP. Results demonstrate that the introduction of the NeMHIP in the ITS context is feasible because security properties are ensured while application performance requirements are satisfied. Therefore, we successfully achieve the trade-off between security and performance.

149-152; International audience; Current window managers are based on the use of overlapping windows, which implies the notion of a window's depth. In order to facilitate the management of windows in desktop environments, recent work has explored their grouping into layers of non-overlapping windows. In this note, we investigate the effect of three visual depth cues on the perception of the depth of such layers: luminosity, blurring and shadow. The paper reports on a controlled experiment that indicates that luminosity helps users to assess the number of layers while blurring and shadow have no effect.

Many net oil-importing developing countries, particularly African economies, have faced economic difficulties with high oil price increases. As a case study, this paper assesses the distributional effects of a rise in various petroleum product prices in Mali using a standard computable general equilibrium model. The results suggest that rising diesel prices primarily affect richer households, while the poorest ones tend to suffer more from higher kerosene and gasoline prices. Overall, the impact of fuel prices on household budgets shows a U-shaped relationship with expenditure per capita. Regardless of the oil product considered, high-income households benefit disproportionately from oil price subsidies. This suggests that petroleum price subsidies are ineffective in protecting the income of poor households compared with a targeted subsidy. Copyright 2010 The author 2009. Published by Oxford University Press on behalf of the Centre for the Study of African Economies. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.

The partial element equivalent circuit method (PEEC) is well suited to extract the conducted electromagnetic disturbances parameters from wiring systems. It provides an efficient tool for the EMC study relevant to automotive cables. However the complete EMC analysis of embedded systems requires also reliable models for the radiated emissions especially at high frequencies. In this paper a new approach based on the PEEC method and involving 3D field calculation is developed to evaluate emissions from radiating cables.

National audience; The development of micro and nanotechnologies requires the design of microrobots and Microsystems able to handle submillimetric objects. Many micromanipulation systems have been built. However, improvement of the performances requires the use of advanced control methods. In this paper, we present the main characteristics of the microworld from a control point of view and some control strategies adapted to the microsystems.

This paper describes the design and the placement of piezoelectric actuators on switched reluctance motors by means of a genetic algorithm (nondominated sorting genetic algorithm II) for the purpose of reducing stator vibrations. Two distinct approaches are presented: one energy-related and the other based on a minimization of the resultant displacement. These methods lead to design and placement strategy for the piezoelectric actuators. A number of optimal actuators obtained using these kinds of approaches is also compared with mechanical finite-element simulations. At last, a solution is achieved in order to validate optimal placement using positive position feedback active filtering.

This paper presents an original design option dedicated to output-filtered pulsewidth modulation inverters used in uninterruptible power systems, embedded networks, or motor drives operating on long cables. It is based on the coupling of interleaved inverter cells by means of intercell transformers (ICTs) and is characterized by very good dynamic behavior on load transients, which is an important issue in such applications. ICT solutions are compared with the classical interleaved solutions using separate inductors. A specific design method is developed to achieve this comparison based on toroidal core shapes. The results obtained with a 600 V, 7.5 kW inverter show the usefulness of ICT-based designs, especially when nanocrystalline magnetic material is used; high specific power and very good dynamic performances are obtained.

National audience; Wiki systems have evolved in two different ways : semantic wikis and peer to peer wikis. Semantic wikis integrate the semantic web technologies in order to improve their structure, the search and the navigation between pages. Peer-to-peer wikis offer a support for massive collaboration, off-line editing mode and an ad-hoc collaboration. The main challenge in designing a peer-to-peer semantic wiki combining both approaches is the merge of wiki pages embedding semantic annotations. Merging algorithms used in peer-to-peer wiki systems have been designed for linear text. They do not handle semantic data. In this paper, we present SWooki the first peer-to-peer semantic wiki. SWooki combines the advantages of both semantic wikis and peer-to-peer wikis. We detail SWooki approach and its merging algorithm, we insist on its characteristics and its functionalities. We conclude by presenting its architecture and its implementation.

In the last decade, several image and video quality metrics have been proposed, which incorporate perceptual quality measures by considering the HVS characteristics. All this metrics do the differences pixel to pixel in image. Therefore a local fidelity of the colour is defined. However, the human visual system is rather sensitive to a global quality. In this paper, we propose a new objective full reference quality metric for colour images called Global Delta E and noted: ~ G DE . This metric is based on human visual system properties in order to obtain the best correspondence with judgments. Some experimentations and assessments prove the performance of our metrics and that interrelationship with the SVH., L'étude du système visuel Humain (SVH) est primordiale pour quantifier la qualité d'une image. Plusieurs travaux ont proposé des métriques de différences de couleurs qui effectuent des différences locales pixel par pixel. Par contre, le système visuel humain est plutôt sensible à une qualité globale. Dans cet article, nous proposons une nouvelle métrique objective de différence couleur basée sur les caractéristiques du système visuel humain. La métrique proposé est appelée Delta E Globale notée : ~ DEG . Quelques expérimentations et évaluations montrent la performance de cette métrique et sa corrélation avec la vision du SVH.

24 pages; National audience; There are many process models for information systems engineering, based on different concepts (activity, product, decision, context, strategy) and then on different process meta-models. These meta-models allow a partial vision of the process engineering. This paper presents a design pattern to model concepts of various process meta-models. This pattern is a first step towards the construction of unified, fitted and multi-views process meta-models.

National audience; Applications dedicated to information sharing, news distribution, service advertisement and discovery all need a communication model where information flows towards any interested receiver, rather than towards specifically set destinations. Content-based communication is a style of communication that perfectly fits the needs of such applications. In this paper we address the problem of supporting content-based communication in partially or intermittently connected mobile ad hoc networks (MANETs). The protocol we designed leverages on the concepts of opportunistic networking and delay-tolerant networking in order to account for the absence of end-to-end connectivity in disconnected MANETs. Simulation results are presented, showing the efficiency of this protocol in a mobile ad hoc network composed of devices carried by pedestrians evolving in a campus environment.

Smart card is today the most widespread secured portable computing device. Four years ago, we addressed the problem of scaling down database techniques for the smart card and we proposed the design of what we called a PicoDBMS, a full-fledged database system embedded in a smart card. Since then, thanks to the hardware progress and to the joint implementation efforts of our team and our industrial partner, this utopian design gave birth to a complete prototype running on an experimental smart card platform. This paper revisits the problem statement in the light of the hardware and applications evolution. Then, it introduces a benchmark dedicated to Pico-style databases and provides an extensive performance analysis of our prototype, discussing lessons learned at experimentation time and helping selecting the appropriate storage and indexation model for a given class of embedded applications. Finally, it draws new research perspectives for data management on secured chips. MOTS-CLES : Bases de donnees embarquees, Confidentialite et protection des donnees, Carte a puce, Controle d'acces, Modeles de stockage et d'indexation, Evaluation de requetes.

Labo L3i; In this paper, we present the use of multimodal content analysis in the MARVEL (Multimodal Analysis of Recorded Video for E-Learning) project. In this project, we record teachers giving their lectures in class and semi-automatically analyze the video-audio content in order to help transfer this lecture into a multimedia course for e-learning. We distinguish two primary goals in this application: scenario extraction (mostly from video) and content indexing (mostly from text and speech). Three objects take place in these goals: the teacher, the screen (for slide projection) and the white-board (for handwriting). These goals and the roles of all objects are explained in details, as well as our preliminary results. Through this application, we are giving some ideas about multimodality analysis and its formalization

L'article explore les enjeux et les pratiques de recherches interdisciplinaires en partenariat. À partir d'une lecture du déroulement de trois projets de recherche, portant sur l'agriculture face à des enjeux sanitaires ou environnementaux, les auteurs analysent l'effet sur la production scientifique des relations établies avec des acteurs du développement. L'hypothèse est que ce partenariat s'inscrit dans une double réalité : l'une, "fictionnelle", qui postule que chercheurs et partenaires s'allient tout en évitant de se confronter vraiment, ce, afin de maintenir le cours des choses ; l'autre, "frictionnelle", qui surgit lorsque, dans une phase d'investissement plus poussé des acteurs, des désaccords apparaissent, ce qui réoriente le cours des événements. Les résultats révèlent la mise en tension de cette double réalité dans chacun des projets. Leur comparaison fait ressortir trois points-clés de la conduite de ces recherches : le degré de constitution et la force du "projet" propre des acteurs impliqués, le rôle pivot d'individus médiateurs et l'attention qu'il convient de porter aux reconfigurations éventuelles du partenariat qu'impliquent les évolutions mêmes du projet., Our paper deals with the issues and practices at stake in the interdisciplinary partnership research field. Taking as a starting point the observation of three on-going research projects confronting agriculture with environmental or sanitary issues, the authors analyse the effects produced, in terms of scientific results, by the relationships established among researchers and development partners. The hypothesis is that the partnership is based on a two-sided reality: fiction, on the one hand, goes with the assumption that while researchers and partners do consider each other as allies, they consistently avoid confrontation in order to let things run their course. Friction, on the other hand, may arise with disagreement and thus alter the course of events. As revealed by the results of the study, this two-sided reality is held in tension within each project. Their comparison brings out three key points required in the management of such projects: the degree of solidarity between the groups concerned, the kingpin role of mediators, and the manner in which the research is conducted to meet changes in the partnership.