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Adjusting Ag deposition power to improve corrosion resistance of ITO/Ag/ITO film for gate driver on array
No full textInternational audienceGate Driver on Array (GOA) can fulfil narrow-frame full screen of display device, but may encounter through-hole burnout during operation due to electrochemical corrosion under high-temperature and high-humidity environments. Through-hole burnout originates from vapor that penetrates display sealant and invades signal-conducting through-hole in GOA, and results from action of electrochemistry and Joule heat. In this work, ITO/Ag/ITO films were deposited by direct current (DC) sputtering using ITO and Ag targets. This work attempts to reduce electrical resistivity, while limiting electrochemical corrosion of film by adjusting Ag deposition power. We found that high crystallinity and smooth morphology can inhibit vapor accumulation for Ag film prepared at a power of 8 kW, along with favorable sheet resistance and etching slope angle as low as 0.31 Ω/sq and 73.1°, respectively. Such film can run normally for 200 h in field test at a temperature of 85 °C and a humidity of 85 % with absence of through-hole corrosion. The outcomes of this work pave the way for industrial application of the narrow-frame full screen with virtues of both low resistance value and electrochemical corrosion resistance
Demonstration that sublinear dendrites enable linearly non-separable computations
No full textDOI preprint: 10.1101/2023.06.01.543223International audienceABSTRACT Theory predicts that nonlinear summation of synaptic potentials within dendrites allows neurons to perform linearly non-separable computations (LNSCs). Using Boolean analysis approaches, we predicted that both supralinear and sublinear synaptic summation could allow single neurons to implement a type of LNSC, the feature binding problem (FBP), which does not require inhibition contrary to the XOR. Notably, sublinear dendritic operations enable LNSCs when scattered synaptic activation generates increased somatic spike output. However, experimental demonstrations of scatter-sensitive neuronal computations have not yet been described. Using glutamate uncaging onto cerebellar molecular layer interneurons, we show that scattered synaptic-like activation of dendrites evoked larger compound EPSPs than clustered synaptic activation, generating a higher output spiking probability. Moreover, we also demonstrate that single interneurons can indeed implement the FBP. We use a biophysical model to predict under what conditions a neuron can implement the FBP and what leads to failures. Experimental results agree with the model-determined conditions and hence validate our protocol as a solid benchmark for a neuron to implement linearly non-separable computations. Since sublinear synaptic summation is a property of passive dendrites we expect that many different neuron types can implement LNSCs
Attenuation of Rayleigh and pseudo surface waves in saturated soil by seismic metamaterials
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Coincidence detector for locating a source
No full textN° de priorité : FR20210012849 20211202N° de demande: WO2022EP83341 20221125Demandeur(s) : UNIV LILLE, CNRS, CENTRALE LILLE INSTITUT, UNIV POLYTECHNIQUE HAUTS DE FRANCEÉgalement publié en tant que : WO2023099355 (A1) 2023-06-0
Advances in AI-Generated Images and Videos
No full textInternational audienceIn recent years generative AI models and tools have experienced a significant increase, especially techniques to generate synthetic multimedia content, such as images or videos. These methodologies present a wide range of possibilities; however, they can also present several risks that should be taken into account. In this survey we describe in detail different techniques for generating synthetic multimedia content, and we also analyse the most recent techniques for their detection. In order to achieve these objectives, a key aspect is the availability of datasets, so we have also described the main datasets available in the state of the art. Finally, from our analysis we have extracted the main trends for the future, such as transparency and interpretability, the generation of multimodal multimedia content, the robustness of models and the increased use of diffusion models. We find a roadmap of deep challenges, including temporal consistency, computation requirements, generalizability, ethical aspects, and constant adaptation
« L’envers des métropoles. Quelques considérations historiques du côté espagnol »
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What are the drivers of eco-innovation? Empirical evidence from French start-ups
No full textInternational audienceThe purpose of this paper is to identify the drivers of eco-innovation in start-ups. Firstly, a discriminant analysis (DA) is applied to study what is distinctive about eco-innovative start-ups as compared to non-eco-innovative start-ups. Secondly, a typology of eco-innovative start-ups is developed using a hierarchical ascendant clustering (HAC). Analyses are carried out using original data from a survey of 120 eco-innovative and non-ecoinnovative French start-ups.Discriminant analyses reveal that the founders of eco-innovative start-ups are differentiated by characteristics related to their environmental education and professional experience. Furthermore, eco-innovative start-ups are distinguished from the non-eco-innovative start-ups by voluntary environmental practices, such as the adoption of corporate social responsibility policies. Finally, we show that there is a diversity of profiles of eco-innovators. In fact, firms cluster into five main profiles and exhibit different eco-innovation drivers. We highlight that the different types of eco-innovators do not face the same difficulties in accessing funds. These findings have important implications for the implementation of public policy designed to promote eco-innovative activity, and they highlight the need to design policies that take into account the distinctive character of each profile.</div
A coupled finite element-discrete element method for the modelling of brake squeal instabilities
No full textInternational audienceThe work presented here proposes a contribution on the analysis of brake squeal phenomenon using a transient coupled finite element-discrete element method (FEM-DEM) simulation with pad surface topography evolution. To build the coupled FEM-DEM model, a non-overlapping strong coupling is first employed between the FEM and DEM subdomains. Second, a new calibration methodology of the DEM microscopic properties is proposed based on the eigenvalue analysis of the full model. The results of the coupled FEM-DEM model show a good agreement in terms of unstable frequencies and the evolution of the pad contact state history when compared to full FEM models, both for new and worn pad topographies. The evolution of the pad surface topography during the transient analysis results in a complex frequency behaviour, with abrupt shifts of instabilities and new operating deflection shapes, in agreement with reported experimental results. The proposed coupled FEM-DEM model thus seems to be a valuable tool for a better understanding of the squeal triggering due to the evolution of the pad surface topography. This contribution paves the way to advanced numerical analyses of brake squeal phenomenon, which triggering conditions are still under investigation
Système de navigation d’un microrobot neurochirurgical
No full textThèse sous confidentialité du jury jusqu’au 17/06/2028 puis sous embargo de l’auteur jusqu’au 17/12/2028.Current neurosurgical tools are limited by their rigid components, which constrain them to straight-line trajectories, making it challenging to access deep brain regions. To address this limitation, Robeauté has developed a minimally invasive microrobot capable of navigating along a 3D trajectory. This thesis aims to design, fabricate, and integrate a steering system at the microrobot’s tip to enable such 3D navigation.The general requirements for developing the steering system include minimal invasiveness, sufficient force for brain navigation, an adapted radius of curvature for desired applications, biocompatibility, minimal tissue damage, and MRI compatibility. Shape memory alloys (SMA) were chosen as the ideal technology due to their high work density, large actuation force, simple design, corrosion resistance, biocompatibility, frictionless, and high fatigue life.The key contributions of this thesis are organized into four main areas: (i) Model development: A realistic electro-thermomechanical model was developed, laying the groundwork for the SMA's use as an actuator, and crucial during the design optimization phase. (ii) Innovative steering system design: A novel micro parallel continuum platform was implemented, with three SMA actuators to achieve the pitch and yaw angles required for 3D navigation. This design ensures stiffness for straight self-alignment and uses small-diameter SMA wires for faster response times, improving efficiency. The prototype achieved a 20° steering angle, with a theoretical curvature radius of 44 mm, and a lateral force of 530 mN, sufficient for brain navigation and meeting mid-term objectives. (iii) Control system implementation: A tip orientation control loop using SMA electrical resistance as feedback eliminated the need for external sensors. A multivariable model accounts strain in function of power and resistance, addressing SMA hysteresis and improving control robustness during cyclic actuation. We also achieve a continuous displacement control with a steady-state error of less than 5% with a settling time of 7 seconds. (iv) Preclinical Validation: The system's feasibility was validated by four preclinical tests. A non-integrated version tested on a post-mortem human model achieved an angle of 19°. Then, an integrated version within the microrobot tested on two post-mortem horse models achieved 17°. Finally, an in-vivo test on an ewe demonstrated full operational functionality with an angle of 31°. These results validated the steering system's Technology Readiness Levels (TRL) from 1 to 5.Building on this success, future research will focus on four optimization areas: (i) amplifying the angle to reduce the radius of curvature and enable more complex trajectories to be obtained, (ii) reducing the scale of the system to make it less invasive, (iii) moving from position control to trajectory control to obtain a precise 3D trajectory, and (iv) include temperature and stress variations in control model characterization to approach real-operating conditions during clinical trials.Les outils neurochirurgicaux actuels sont limités par leur structure rigide, qui les contraint à des trajectoires en ligne droite, rendant difficile l'accès aux régions profondes du cerveau. Pour répondre à cette limitation, Robeauté a développé un microrobot minimalement invasif, capable de naviguer le long d'une trajectoire 3D. Cette thèse vise à concevoir, fabriquer et intégrer un système de navigation au bout du microrobot pour permettre cette navigation 3D.Le cahier des charges pour le développement du système de navigation inclut une invasivité minimale, une force suffisante pour orienter le microrobot dans le cerveau, un rayon de courbure adapté, des dommages tissulaires minimaux, la biocompatibilité et la compatibilité avec l'IRM. Les alliages à mémoire de forme (AMF) ont été choisis comme technologie idéale en raison de leur grande densité de travail, leur force d'actionnement, leur conception simple, leur résistance à la corrosion, leur biocompatibilité, l'absence de friction et leur longue durée de vie.Les principales contributions de cette thèse sont divisées en quatre axes : (i) Développement de modèle : un modèle électro-thermomécanique réaliste a été développé, posant les bases de l'utilisation des AMF comme actionneurs, essentiel pour l'optimisation de la conception. (ii) Conception innovante du système de navigation : une nouvelle plateforme micro-parallèle continue a été mise en place, avec trois actionneurs AMF permettant d'obtenir les angles de tangage et de lacet nécessaires à la navigation 3D. Cette conception garantit une rigidité pour l'auto-alignement. Elle utilise des fils AMF de petit diamètre pour des temps de réponse plus rapides, améliorant ainsi l'efficacité. Le prototype a atteint un angle de 20°, avec un rayon de courbure théorique de 44 mm et une force latérale de 530 mN, suffisante pour la navigation dans le cerveau, atteignant ainsi les objectifs à moyen terme. (iii) Mise en œuvre du système de contrôle : une boucle de contrôle de l'orientation de la pointe, utilisant la résistance électrique de l'AMF comme rétroaction, a permis d'éliminer le besoin de capteurs externes. Un modèle multivariable relie la déformation à la puissance et à la résistance électrique, traitant l'hystérésis de l'AMF et améliorant la robustesse du contrôle pendant l'actionnement cyclique. Nous avons également réalisé un contrôle du déplacement continu avec une erreur de régime permanent inférieure à 5 % et un temps de stabilisation de 7 secondes. (iv) Validation préclinique : le système de navigation développé dans cette thèse a été validé par quatre tests précliniques. Une version non intégrée testée sur un modèle humain post-mortem a atteint un angle de 19°. Ensuite, une version intégrée au reste du microrobot, testée sur deux modèles équins post-mortem, a atteint 17°. Enfin, un test in vivo sur une brebis a démontré une fonctionnalité opérationnelle avec un angle de 31°. Ces résultats ont validé les niveaux de maturité technologique (TRL) du système, allant de 1 à 5.Fort de ce succès, les recherches futures se concentreront sur quatre axes d'optimisation : (i) augmenter l'angle pour réduire le rayon de courbure et permettre des trajectoires plus complexes, (ii) réduire l'échelle du système pour le rendre moins invasif, (iii) passer du contrôle de position au contrôle de trajectoire pour obtenir une trajectoire 3D précise, et (iv) inclure les variations de température et de contrainte dans la caractérisation du modèle de contrôle afin de se rapprocher des conditions réelles lors des essais cliniques
"L'artiste est à son œuvre" - Improvisation poétique et artistique, Doctoriales du LARSH, DeScripto: Texte improvisé pendant qu'un artiste peint, pendant la déclamation, ce que le texte lui inspire
No full textIn order to introduce Soilio Coulibaly's talk, a doctoral student improvised a poem.As the poem is recited, the painter creates a work of art in front of his audience.Through the words, the irregular brushes of paint come to life under the artist's impetus.Through the flat tints, the poet's improvised words flow all the more freely.The voice influences the drawing, the drawing influences the voice, in a collective work that is nothing without the two voices that make it up.This artistic collaboration took place during the 2024 "doctoriales". The theme of these doctoriales was the reversal of the classics: the presentation of research, but from a proactive point of view.Through this joint performance, Soilio Coulibaly was able to present the creative side of his thesis, as well as the artistic activity he pursues alongside his research.His fellow doctoral student was able to show, in addition to his fondness for 19th-century poetry, the more intimate - and also more secret - relationship he has with poetic creation.Afin d'introduire l'intervention de Soilio Coulibaly, doctorant à l'Université de Valenciennes, un collègue doctorant improvise un poème.Durant la déclamation dudit poème, le peintre crée une œuvre devant son public.Au travers des mots, les aplats irréguliers de peinture prennent vie sous la fougue de l'artiste.Au travers des aplats, les mots improvisés du poète s'écoulent d'autant plus librement.La voix influence le dessin, le dessin influence la voix, dans une œuvre collective qui n'est rien sans les deux voies qui la constituent.Cette collaboration artistique a eu lieu lors des doctoriales du LARSH de 2024. Le thème de ces doctoriales était le renversement des classiques : la présentation de la recherche, mais sous un angle qui suppose la participation active de ceux à qui elle est présentée.Par cette performance commune, Soilio Coulibaly a pu présenter le versant créatif de sa thèse, ainsi que l'activité d'artiste qu'il mène en parallèle de ses recherches.Son collègue doctorant a pu montrer, en plus de sa tendresse pour la poésie du XIXe siècle, le rapport plus intime - plus secret, aussi - qu'il entretient avec la création poétique