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Reconstructing past history from whole-genomes: an ABC approach handling recombining data.
No full textInternational audienceIn population genetics, a key interest is to reconstruct the demographic history of a population using its genetic data. This history can be characterized by multiple events such as migration of individuals, admixture with another population, or changes in population size. With the availability of large-scale genomic data numerous methods have arisen for untangling complicated histories or retrieving a detailed picture of a population at different time periods.Although genomes are known to be extremely informative about demography, there are many ways to extract this information. We present an approach designed for inferring past population sizes for an intermediate number of fully sequenced genomes. It relies on Approximate Bayesian Computation (ABC), a simulation-based statistical framework for generic model comparison and parameter inference. We demonstrated how the specificities of DNA sequencing data (namely haplotypic information, long range genetic correlation and genotyping errors) can be handled using ABC and fast genetic simulators, and further infer histories of successive bottleneck and expansions in human populations
Stability Analysis and Output-Feedback Control Design for Time-Delay Systems
No full textInternational audienceThe aim of this paper is to present new results on H ∞ control synthesis, via output-feedback, for time-delay linear systems. We extend the use of the finite order LTI system, called comparison system, to design a controller which depends not only on the output at the present time and maximum delay, but also on an arbitrary number of values between those. This approach allows us to increase the maximum stable delay without requiring any additional information. All methods presented here consider time-delay systems control design with classical numeric routines based on H ∞ theory. An illustrative example is presented
Visualizing Apparent Personality Analysis with Deep Residual Networks
No full textInternational audienceAutomatic prediction of personality traits is a subjective task that has recently received much attention. Specifically, automatic apparent personality trait prediction from mul-timodal data has emerged as a hot topic within the filed of computer vision and, more particularly, the so called " looking at people " sub-field. Considering " apparent " personality traits as opposed to real ones considerably reduces the subjectivity of the task. The real world applications are encountered in a wide range of domains, including entertainment , health, human computer interaction, recruitment and security. Predictive models of personality traits are useful for individuals in many scenarios (e.g., preparing for job interviews, preparing for public speaking). However, these predictions in and of themselves might be deemed to be untrustworthy without human understandable supportive evidence. Through a series of experiments on a recently released benchmark dataset for automatic apparent personality trait prediction, this paper characterizes the audio and visual information that is used by a state-of-the-art model while making its predictions, so as to provide such supportive evidence by explaining predictions made. Additionally, the paper describes a new web application, which gives feedback on apparent personality traits of its users by combining model predictions with their explanations
Etudes expérimentales et numériques de la pyrolyse et l’oxydation du charbon pulvérisé dans les flammes étirées de méthane/oxygène/azote
No full textIn the present work, a laboratory-scale laminar strained configuration is used to investigate the characteristics of pulverized coal devolatilization and oxidation in a mixture of CH4/O2/N2 reactive flow both in conventional air conditions and in oxygen-enriched combustion conditions. Two optical diagnostics, Flame Emission Spectroscopy and measurement of spontaneous emission, are employed for the characterization of flame structure. The spatial concentration evolution of three excited radicals, OH*, CH*and C*2 , are measured and analyzed.1-D simulations using detailed gas-phase kinetics including OH*, CH*, and C*2 sub-mechanisms and coal combustion submodels are performed and compared with experimental data. Qualitative comparison with experiments showed that the current numerical configuration was suitable for the prediction of OH*, CH* and C*2 emission. The predicted results differed with changes to the coal sub-models and kinetic parameters. The devolatilization model and volatile matters seem to play more important roles.Dans ce travail, une configuration laminaire stratifiée est utilisée afin d’étudier les caractéristiques de la pyrolyse et de l’oxydation du charbon pulvérisé dans un mélange de flux réactif à la fois dans les conditions atmosphériques conventionnelles et dans des conditions de combustion enrichie en oxygène. Deux diagnostics optiques, la spectroscopie d’émission de flamme et la mesure de l’émission spontanée sont utilisés pour caractériser la structure de la flamme. Les profiles de concentration de trois radicaux excités, OH*, CH* and C*2 sont mesurés et analysés.Des simulations 1-D utilisant la cinétique détaillée y compris des sous-mécanismes de OH*, CH* and C*2 et de combustion de charbon sont effectuées et comparées avec des données expérimentales. La comparaison qualitative a montré que la configuration numérique actuelle était appropriée pour la prédiction des émissions de OH*, CH* and C*2. Les résultats prédits par l’approche numérique diffèrent avec les modifications apportées aux sous-modèles de charbon et aux paramètres cinétiques. Le modèle de pyrolyse et les matières volatiles semblent jouer des rôles plus importants
A Formal Approach for the Verification of AWS IAM Access Control Policies
No full textPart 3: SecurityInternational audienceCloud computing offers elastic, scalable and on-demand network access to a shared pool of computing resources, such as storage, computation and others. Resources can be rapidly and elastically provisioned and the users pay for what they use. One of the major challenges in Cloud computing adoption is security and in this paper we address one important security aspect, the Cloud authorization. We have provided a formal Attribute Based Access Control (ABAC) model, that is based on Event-Calculus and is able to model and verify Amazon Web Services (AWS) Identity and Access Management (IAM) policies. The proposed approach is expressive and extensible. We have provided generic Event-Calculus modes and provided tool support to automatically convert JSON based IAM policies in Event-Calculus. We have also presented performance evaluation results on actual IAM policies to justify the scalability and practicality of the approach
NDN Synchronization: iRoundSync, an Improved RoundSync
No full textInternational audienceThe use of Named Data Networking (NDN) for distributed multi-user applications, e.g. group messaging and file sharing, requires NDN synchronization protocols to maintain the same shared dataset (and its updates) among all nodes. ChronoSync, RoundSync, and PartialSync are some proposals to address this issue.Here we focus on the state-of-the-art protocol RoundSync: we study its core features, that permit participating nodes to detect, propagate, and reconcile all changes. Particular attention is given to the case of multiple changes per round. We then propose an improved variant, iRoundSync, that exchanges fewer messages in the multiple-change case and is more resilient to packet losses. We quantify the performance gain of iRoundSync on a simple topology
Delay Margin in Controlling a Furuta Pendulum
No full textInternational audienceThis paper focuses on the design of an LQR based control scheme for the stabilization of the Furuta Pendulum in its unstable equilibrium point at the upright position. More precisely, we are interested in characterizing the corresponding delay margin under the assumption that the feedback loop includes time-delay. The paper provides an explicit tool to compute the critical delay value in the state feedback loop and a delicate tuning to reach larger delay values. In order to illustrate the effectiveness of the proposed control scheme, some numerical results are presented
Introducing Individual Travellers in Future Mobility Scenarios
No full textInternational audienceThe main purpose of future studies in urban mobility is to raise stakeholder awareness for new tendencies and developments in the coming years, looking towards 2030 up to 2050. Most of these studies are not pretending to predict the future of mobility systems but to develop possible scenarios for future developments. A wide array of literature on the future of urban mobility is available, it ranges from scientific articles to consulting papers and technical studies or reports across multiple domains. Anticipatory (or normative) scenarios are especially worth of interest for industrial actors for highlighting visions of mobility, whether optimistic (utopian), pessimistic (dystopian) or neutral. Yet, most future mobility scenarios tend to consider the travelers of tomorrow as part of a rather homogeneous group. According to sociological evolutions of urban mobility, some parts of the population will have a great number of advantages, while others will have difficulties and accessibility problems. After selecting three representative scenarios in the literature (utopian, dystopian and dystopia avoidance), our goal is to revisit the scenarios by developing the narratives of mobility behaviors of future travelers. We propose to view the various scenarios from the personal perspective of the individuals affected by the changes of the urban mobility system. The contribution is twofold: (1) a methodical approach to intersect existing anticipatory scenarios, trends in social developments and projected mobility profiles; (2) an illustration of three anticipatory scenarios enriched by the expected behavior of different traveler groups
Scalable extraction of small woody features (swf) at the pan-european scale using open source solutions
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Linearly-polarized electronically reconfigurable transmitarray antenna with 2-bit phase resolution in Ka-band
No full textInternational audienceThis paper demonstrates the numerical results of a 196-element linearly-polarized electronically reconfigurable transmitarray in Ka-band. The proposed array architecture is based on a wideband and low-loss unit-cell with 2 bits of phase resolution (90°-step between two consecutive phase states). The unit-cell size (length × width × height) is equal to 5.1×5.1×1.3 mm3 and it is composed of six metal layers, three dielectric substrates and two bonding films. Four p-i-n diodes are soldered on the radiating elements in order to control the transmission phase. The full-wave simulations of the transmitarray are in agreement with the results predicted by using an ad-hoc simulation tool based on analytical model and electromagnetic simulations. The transmitarray antenna presents a maximum gain of 22.9 dBi, corresponding to an aperture efficiency of 32.3%, and a side-lobe level equal to -18.1 dB at 29 GHz. The computed 3-dB gain-bandwidth is larger than 15.9% around 29 GHz. © 2017 IEEE