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Le rôle de la motivation intrinsèque basée sur le progrès dans l'apprentissage : preuves du comportement humain et orientations futures progrès
No full textIntrinsic motivation – the desire to do things for their inherent joy and pleasure – has received its first share of scientific attention over 70years ago, ever since we saw monkeys solving puzzles for free. Since then, research on intrinsic motivation has been steadily gaining momentum. We have come to understand, in the context of learning and discovery, that intrinsic motivation (namely, intrinsically motivated information-seeking) is foundational for the biological and technological success of our species. But where does intrinsic motivation to learn and seek information come from? Today, with the thriving synergy between perpetually advancing fields of psychology, neuroscience, and computer science, we are well positioned to investigate this question. The Learning Progress Hypothesis (LPH) proposes that humans are motivated by feelings of and/or beliefs about progress in knowledge (including progress in competence). In artificial learners, progressbased intrinsic motivation enables autonomous exploration of the environment (including the agent’s own body), resulting in better performance, more efficient learning, and richer skill sets. Due to similar computational challenges facing artificial and biological learners, researchers have proposed that progress-based intrinsic motivation might have evolved in humans to help us transition from babies with few skills and little knowledge to knowledgeable grownups capable of performing many sophisticated tasks. The Learning Progress Hypothesis (LPH) is attractive, not only because it is consistent with several studies of human curiosity, but also because it resonates with existing theories on metacognitive self-regulation in learning. However, the LPH has not been extensively studied using behavioral experimentation.This thesis provides an empirical examination of the LPH. We introduce a novel experimental paradigm where participants explore multiple learning activities, some easy, others difficult. The activities involve guessing the binary category of randomly presented stimuli. To let their intrinsic motivation shine, we did not provide any material incentives encouraging specific behaviors or strategies – we simply observed which activities people engaged in and how their knowledge about these activities unfolded over time. We present statistical analyses and a computational model that support the LPH.This thesis also suggests ideas for future investigations into progressbased motivation. These ideas are inspired by a pilot study in which we asked participants to practice a naturalistic sensorimotor skill (a video game) over the course of 3 sessions spanning 5 days. [...]We conclude the thesis with an extended discussion of our findings, where we examine some limitations of our experiments and propose promising future steps. In summary, we believe the behavioral paradigms introduced in this thesis should be reused to not only replicate our results, but also to advance the scientific research of intrinsically motivated information-seeking.La motivation intrinsèque - le désir de faire les choses pour la joie et le plaisir inhérent qu’ils procurent - a suscité l’intérêt des chercheurs pour la première fois il y a plus de 70 ans, en voyant des singes résoudre des énigmes gratuitement. Depuis, la recherche sur la motivation intrinsèque n’a cessé de prendre de l’ampleur. Dans le contexte de l’apprentissage et des comportements de découverte, il est aujourd’hui entendu , que la motivation intrinsèque (c’est-à-dire la recherche intrinsèquement motivée d’informations) est fondamentale au progrès biologique et technologique de notre espèce. Mais d’où vient la motivation intrinsèque pour apprendre et pour rechercher des informations ? Aujourd’hui, avec la synergie florissante entre les domaines en constante évolution de la psychologie, des neurosciences et de l’informatique, nous sommes en capacité d’étudier cette question.L’hypothèse de progrès d’apprentissage (Learning Progress Hypothesis,ou LPH en anglais) propose que les humains sont motivés par leurs sentiments et/ou croyances relatifs à leurs progrès de connaissances (y compris les progrès dans les compétences). Chez les apprenants artificiels, la motivation intrinsèque basée sur le progrès d’apprentissage permet une exploration autonome de l’environnement (y compris le propre corps de l’agent), ce qui se traduit par de meilleures performances, un apprentissage plus efficace et un ensemble de compétences plus riches. En raison des défis informatiques similaires auxquels sont confrontés les apprenants artificiels et biologiques, des chercheurs ont proposé que la motivation intrinsèque basée sur le progrès ait pu évoluer chez l’Homme, pour nous aider à passer de bébés avec peu de compétences et peu de connaissances, à des adultes bien informés capables d’effectuer de nombreuses tâches sophistiquées. La LPH est attrayante, non seulement parce qu’elle est cohérente avec plusieurs études sur la curiosité humaine, mais aussi parce qu’elle résonne avec les théories existantes sur l’autorégulation métacognitive dans l’apprentissage. Cependant, la LPH n’a pas été largement étayée par l’expérimentation comportementale. Cette thèse propose un examen empirique de la LPH. Nous introduisons un nouveau paradigme expérimental où les participants explorent plusieurs activités d’apprentissage, certaines faciles, d’autres difficiles. Les activités consistent à deviner la catégorie binaire de stimuli présentés au hasard. Pour laisser briller leur motivation intrinsèque, nous n’avons fourni aucune incitation matérielle encourageant des comportements ou des stratégies spécifiques - nous avons simplement observé dans quelles activités les personnes s’engageaient et comment leurs connaissances sur ces activités se développaient au fil du temps. Nous présentons des analyses statistiques et un modèle de calcul prenant en charge la LPH.[...]. Nous concluons la thèse par une discussion approfondie de nos résultats, où nous examinons certaines limites de nos expériences et proposons des étapes futures prometteuses. En résumé, nous pensons que les paradigmes comportementaux introduits dans cette thèse devraient être réutilisés non seulement pour reproduire nos résultats,mais aussi pour faire avancer la recherche scientifique sur la recherche d’informations intrinsèquement motivée
OpReg-Boost: Learning to Accelerate Online Algorithms with Operator Regression
No full textCode available here https://github.com/nicola-bastianello/reg4optInternational audienceThis paper presents a new regularization approach -- termed OpReg-Boost -- to boost the convergence and lessen the asymptotic error of online optimization and learning algorithms. In particular, the paper considers online algorithms for optimization problems with a time-varying (weakly) convex composite cost. For a given online algorithm, OpReg-Boost learns the closest algorithmic map that yields linear convergence; to this end, the learning procedure hinges on the concept of operator regression. We show how to formalize the operator regression problem and propose a computationally-efficient Peaceman-Rachford solver that exploits a closed-form solution of simple quadratically-constrained quadratic programs (QCQPs). Simulation results showcase the superior properties of OpReg-Boost w.r.t. the more classical forward-backward algorithm, FISTA, and Anderson acceleration
Characterization of the Formability of High-Purity Polycrystalline Niobium Sheets for Superconducting Radiofrequency Applications
No full textInternational audienceThe forming limit diagram (FLD) of high-purity niobium sheets used for the manufacturing of superconducting radiofrequency (SRF) cavities is presented. The Marciniak (in-plane) test was used with niobium blanks with a thickness of 1 mm and blank carriers of annealed oxygen-free electronic (OFE) copper. A high formability was measured, with an approximate true major strain at necking for plane strain of 0.44. The high formability of highpurity niobium is likely caused by its high strain rate sensitivity of 0.112. Plastic strain anisotropies (r-values) of 1.66, 1.00, and 2.30 were measured in the 0 deg, 45 deg, and 90 deg directions. However, stress-strain curves at a nominal strain rate of ∼10 −3 s −1 showed similar mechanical properties in the three directions. Theoretical calculations of the forming limit curves (FLCs) were conducted using an analytical two-zone model. The obtained results indicate that the anisotropy and strain rate sensitivity of niobium affect its formability. The model was used to investigate the influence of strain rate on strains at necking. The obtained results suggest that the use of high-speed sheet forming should further increase the formability of niobium
Proving Feasibility of a Docking Mission: A Contractor Programming Approach
No full textInternational audienceRecent advances in computational power, algorithms, and sensors allow robots to perform complex and dangerous tasks, such as autonomous missions in space or underwater. Given the high operational costs, simulations are run beforehand to predict the possible outcomes of a mission. However, this approach is limited as it is based on parameter space discretization and therefore cannot be considered a proof of feasibility. To overcome this limitation, set-membership methods based on interval analysis, guaranteed integration, and contractor programming have proven their efficiency. Guaranteed integration algorithms can predict the possible trajectories of a system initialized in a given set in the form of tubes of trajectories. The contractor programming consists in removing the trajectories violating predefined constraints from a system’s tube of possible trajectories. Our contribution consists in merging both approaches to allow for the usage of differential constraints in a contractor programming framework. We illustrate our method through examples related to robotics. We also released an open-source implementation of our algorithm in a unified library for tubes, allowing one to combine it with other constraints and increase the number of possible applications
Simultaneous Up-Conversion Based on a Co- & Counter-Directions SOA-MZI Sampling Mixer with Standard & Differential Modulation Modes
No full textInternational audienceSimulation and experimental performance analyses of simultaneous up-converted signals, for the first time, were investigated utilizing a semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI) sampling mixer in co- and counter-directions for standard and differential modulation modes. An optical pulse source at a sampling frequency of fs = 15.6 GHz was used as a sampling signal. The IF signal channels carrying quadrature phase shift keying (QPSK) data at frequencies fm were up-converted at different mixing frequencies up to 195.5 GHz. Using the Virtual Photonics Inc. (VPI) simulator, we realized mixed QPSK signals and studied their characteristics through a conversion gain and an error vector magnitude (EVM). Simulations of up mixing operated in a frequency range up to 158 GHz. For the standard modulation in the co-direction, the conversion gain decreased from 43.3 dB at the mixing frequency of 16.6 GHz to 21.8 dB at 157 GHz for the first channel and from 43 dB at 17.6 GHz to 21 dB at 158 GHz for the second channel. The use of the differential modulation principle improved the conversion gain by about 10 dB at 195.5 GHz compared to standard modulations in co- and counter-directions. The EVM reached, respectively, 15.5 and 17.5% for the differential modulation in both configurations, at the bit rate of 100 Gbit/s at 195.5 GHz. The benefit provided by the differential modulation was that EVM values were shifted by 20% for all channels in both configurations at 100 Gbit/s. In the real measurement, we confirmed that co-directional conversion exhibited a better performance than the counter-directional operation. In addition, the real mixed signal exhibited lower efficiency and quality in comparison with simulated signals due to the sensitivity of the receiver
A linearized ALE Boundary Element Method for flexible 3D bluff bodies in potential flows: towards application to airship aeroelasticity
No full textInternational audienceEffects of fluid-structure coupling on the dynamic behavior of flexible airships can be modeled with a potential, incompressible, inviscid flow. A new formalism to study the linear behavior of a fluid-structure interface in a time-dependent ambient flow is introduced. The fluid equations are condensed at the interface with the help of integral equations, which are expressed as a function of the structure variables defined on a time-independent reference configuration with an Arbitrary Lagrangian-Eulerian (ALE) formalism. The features of the Boundary Element Method (BEM) used to solve this problem numerically are exhibited. The approximations of this method associated with both linearization and discretization are quantified to validate the model. A simplified flexible airship test case model is studied to illustrate a practical application of the method
La biopharmacie, les "big pharma", les réseaux et ... les vaccins ?
No full textInternational audienc
The Impact of Healthcare Traffic Over H2H and M2M Networks During the Spread Phase of Pandemic Diseases
No full textInternational audienceRecently, the coronavirus pandemic has caused widespread panic around the world. Modern technologies can be used to monitor and control this highly contagious disease. A plausible solution is to equip each patient who is diagnosed with or suspected of having COVID-19 with sensors that can monitor various healthcare and location parameters and report them to the desired facility to control the spread of the disease. However, the simultaneous communication of numerous sensors installed in the majority of an area's population results in a huge burden on existing Long-Term Evolution (LTE) networks. The existing network becomes oversaturated because it has to manage two kinds of traffic in addition to normal traffic (text, voice, and video): healthcare traffic generated by a large number of sensors deployed over a huge population, and extra traffic generated by people contacting their family members via video or voice calls. In pandemics, e-healthcare traffic is critical and should not suffer packet loss or latency due to network overload. In this research, we studied the performance of existing networks under various conditions and predicted the severity of network degradation in an emergency. We proposed and evaluated three schemes (doubling bandwidth, combining LTE-A and LTE-M networks, and request queuing) for ensuring quality of service (QoS) of healthcare sensor (HCS) network traffic without perturbation from routine human-to-human or machine-to-machine communications. Finally, we simulated all proposed schemes and compared them with existing network scenarios. The results have showed that when we have doubled the bandwidth the SCR of all traffic was 100% as same as the Queue strategy. However, when we prioritized the HCS traffic the SCR has recorded 100%, while H2H and M2M traffic has recorded 73%. When we used hybrid network LTE-A and LTE-M network, the HCS and H2H traffic has recorded 100% and M2M traffic has recorded 70%. After analyzing the results, we conclude that our proposed queuing schemes performed well in all conditions and provide the best QoS for HCS traffic
Sustainable seawater desalination: Current status, environmental implications and future expectations
No full textInternational audienceDesalination is the process of making the saltwater of the Earth's oceans drinkable and could be a solution to droughts, especially in warmer and drier regions. However, the concerns of high cost and ecosystem degradation have always restricted the growth of the desalination industry and necessitated further studies and corrective actions. As desalination is becoming essential for our planet, the development of sustainable and energy-efficient technologies to produce clean water is a key research topic. Considering the worth of seawater desalination to fulfill the needs of the Earth habitants, this article explores how this process can be made less problematic to use as a real solution, not just a temporary opportunity. Desalination methods will play a key role, so all the major options and their environmental footprints are discussed, considering the energy requirements in particular of each process. A brief but up-to-date summary of the current status and future trends of desalination technologies is provided. Available equipment and procedures that are being developed to make desalination a sustainable process are explored. Finally, based on a detailed review, we highlight the future trends and issues to make informed decisions pertaining to the future research and development projects of this sector
Insights into the integration of the SDGs in engineering program curricula as seen through the prism of the perceptions of engineering students ans educators
No full textInternational audienceIn this paper, we offer insight into how the UN Sustainable Development Goals (SDGs) are being integrated into engineering programs. We investigate the question : “what opportunities and barriers should we take into consideration in order to better integrate the SDGs into engineering programs ?” We undertook two exploratory focus group studies with engineering students and academic participants that explored their perception of SDGs’ integration into their programs. Our results show significant differences between the perceptions of students and academics, and this indicates the need for a more comprehensive and balanced integration of the SDGs into engineering curricula. We particularly recommend a transdisciplinary teaching approach involving a close relation between technical and human disciplines