Publications

2020

• Popularity-Based Full Replica Caching For Erasure-Coded Distributed Storage Systems
  
  • Ruty Guillaume
  • Baccouch Hana
  • Nguyen Victor
  • Surcouf André
  • Rougier Jean Louis
  • Boukhatem Nadia
  Cluster Computing, Springer Verlag, 2020.
• The POTUS Corpus, a database of weekly addresses for the study of stance in politics and virtual agents
  
  • Janssoone Thomas
  • Bailly Kevin
  • Richard Gael
  • Clavel Chloé
  , 2020, pp.11 - 16. One of the main challenges in the field of Embodied Conversational Agent (ECA) is to generate socially believable agents. The common strategy for agent behaviour synthesis is to rely on dedicated corpus analysis. Such a corpus is composed of multimedia files of socio-emotional behaviors which have been annotated by external observers. The underlying idea is to identify interaction information for the agent's socio-emotional behavior by checking whether the intended socio-emotional behavior is actually perceived by humans. Then, the annotations can be used as learning classes for machine learning algorithms applied to the social signals. This paper introduces the POTUS Corpus composed of high-quality audio-video files of political addresses to the American people. Two protagonists are present in this database. First, it includes speeches of former president Barack Obama to the American people. Secondly, it provides videos of these same speeches given by a virtual agent named Rodrigue. The ECA reproduces the original address as closely as possible using social signals automatically extracted from the original one. Both are annotated for social attitudes, providing information about the stance observed in each file. It also provides the social signals automatically extracted from Obama's addresses used to generate Rodrigue's ones.
• Motion Correction for brain PET using a Real Time Motion Capture System
  
  • Chemli Y.
  • Tétrault M.-A.
  • Marin T.
  • Toussaint M.
  • Bloch Isabelle
  • El Fakhri G.
  • Normandin M.
  • Ouyang J.
  • Petibon Y.
  , 2020.
• MR based PET motion correction for irregular respiratory motion
  
  • Djebra Y.
  • Marin T.
  • Han P.
  • Chemli Y.
  • Bloch Isabelle
  • El Fakhri G.
  • Ouyang J.
  • Petibon Y.
  • Ma C.
  , 2020.
• Analyse de représentations spatiales de la musique par des opérateurs simples de morphologie mathématique
  
  • Lascabettes P.
  • Bloch Isabelle
  • Agon C.
  , 2020.
• Raman-free fibered photon-pair source
  
  • Cordier Martin
  • Delaye Philippe
  • Gérôme Frédéric
  • Benabid Fetah
  • Zaquine Isabelle
  Scientific Reports, Nature Publishing Group, 2020, 10, pp.1650. Raman-scattering noise in silica has been the key obstacle toward the realisation of high quality fiber-based photon-pair sources. Here, we experimentally demonstrate how to get past this limitation by dispersion tailoring a xenon-filled hollow-core photonic crystal fiber. The source operates at room temperature, and is designed to generate Raman-free photon-pairs at useful wavelength ranges, with idler in the telecom, and signal in the visible range. We achieve a coincidence-to-accidentals ratio as high as 2740 combined with an ultra low heralded second order coherence g(2)H(0)=0.002, indicating a very high signal to noise ratio and a negligible multi-photon emission probability. Moreover, by gas-pressure tuning, we demonstrate the control of photon frequencies over a range as large as 13 THz, covering S-C and L telecom band for the idler photon. This work demonstrates that hollow-core photonic crystal fiber is an excellent platform to design high quality photon-pair sources, and could play a driving role in the emerging quantum technology. (10.1038/s41598-020-58229-7)
  DOI : 10.1038/s41598-020-58229-7
• On the decoding of Barnes-Wall lattices
  
  • Corlay Vincent
  • Boutros Joseph
  • Ciblat Philippe
  • Brunel Loïc
  , 2020. We present new efficient recursive decoders for the Barnes-Wall lattices based on their squaring construction. The analysis of the new decoders reveals a quasi-quadratic complexity in the lattice dimension. The error rate is shown to be close to the universal lower bound in dimensions 64 and 128.
• Power efficient all-fiberized 12-core erbium/ytterbium doped optical amplifier
  
  • Mélin Gilles
  • Kerampran Romain
  • Monteville Achille
  • Bordais Sylvain
  • Robin Thierry
  • Landais David
  • Lebreton Aurélien
  • Jaouën Yves
  • Taunay Thierry
  , 2020, pp.M4C.2. (10.1364/OFC.2020.M4C.2)
  DOI : 10.1364/OFC.2020.M4C.2
• Introduction of 3D Modeling and Peripheral Nerve Tractography in the Management of Pelvic Tumors
  
  • Goulin Jeanne
  • Meignan Pierre
  • Blanc Thomas
  • Delmonte Alessandro
  • Peyrot Quoc
  • Berteloot Laureline
  • Boddaert Nathalie
  • Bloch Isabelle
  • Sarnacki Sabine
  , 2020.
• Conveying Emotions Through Device-Initiated Touch
  
  • Teyssier Marc
  • Bailly Gilles
  • Pelachaud Catherine I
  • Lecolinet Eric
  IEEE Transactions on Affective Computing, Institute of Electrical and Electronics Engineers, 2020, pp.1-1. Humans have the ability to convey an array of emotions through complex and rich touch gestures. However, it is not clear how these touch gestures can be reproduced through interactive systems and devices in a remote mediated communication context. In this paper, we explore the design space of device-initiated touch for conveying emotions with an interactive system reproducing a collection of human touch characteristics. For this purpose, we control a robotic arm to touch the forearm of participants with different force, velocity and amplitude characteristics to simulate human touch. In view of adding touch as an emotional modality in human-machine interaction, we have conducted two studies. After designing the touch device, we explore touch in a context-free setup and then in a controlled context defined by textual scenarios and emotional facial expressions of a virtual agent. Our results suggest that certain combinations of touch characteristics are associated with the perception of different degrees of valence and of arousal. Moreover, in the case of non-congruent mixed signals (touch, facial expression, textual scenario) not conveying a priori the same emotion, the message conveyed by touch seems to prevail over the ones displayed by the visual and textual signals. (10.1109/TAFFC.2020.3008693)
  DOI : 10.1109/TAFFC.2020.3008693
• Spiking Neural Networks and online learning: An overview and perspectives
  
  • Lobo Jesus
  • del Ser Javier
  • Bifet Albert
  • Kasabov Nikola
  Neural Networks, Elsevier, 2020, 121, pp.88-100. Applications that generate huge amounts of data in the form of fast streams are becoming increasingly prevalent, being therefore necessary to learn in an online manner. These conditions usually impose memory and processing time restrictions, and they often turn into evolving environments where a change may affect the input data distribution. Such a change causes that predictive models trained over these stream data become obsolete and do not adapt suitably to new distributions. Specially in these non-stationary scenarios, there is a pressing need for new algorithms that adapt to these changes as fast as possible, while maintaining good performance scores. Unfortunately, most off-the-shelf classification models need to be retrained if they are used in changing environments, and fail to scale properly. Spiking Neural Networks have revealed themselves as one of the most successful approaches to model the behavior and learning potential of the brain, and exploit them to undertake practical online learning tasks. Besides, some specific flavors of Spiking Neural Networks can overcome the necessity of retraining after a drift occurs. This work intends to merge both fields by serving as a comprehensive overview, motivating further developments that embrace Spiking Neural Networks for online learning scenarios, and being a friendly entry point for non-experts. (10.1016/j.neunet.2019.09.004)
  DOI : 10.1016/j.neunet.2019.09.004
• Tunable All-Optical Modulation and Building Blocks for Optical Neurons at Mid-Infrared Wavelength
  
  • Spitz O
  • Wu J
  • Herdt A
  • Carras M
  • Maisons G
  • Elsässer W
  • Wong C.-W
  • Grillot F
  , 2020. Quantum cascade lasers (QCLs) under optical feedback can output several non-linear dynamics whose properties depend on the reinjected light polarization. We demonstrate all-optical modulation, thresholding and excitability in QCLs, to experimentally build basic optical neurons.
• Weighted Empirical Risk Minimization: Transfer Learning based on Importance Sampling
  
  • Clémençon Stéphan
  • Vogel Robin
  • Achab Mastane
  • Tillier Charles
  , 2020. We consider statistical learning problems, when the distribution P of the training observations Z 1 ,. .. , Z n differs from the distribution P involved in the risk one seeks to minimize (referred to as the test distribution) but is still defined on the same measurable space as P and dominates it. In the unrealistic case where the likelihood ratio Φ(z) = dP/dP (z) is known, one may straightforwardly extends the Empirical Risk Minimization (ERM) approach to this specific transfer learning setup using the same idea as that behind Importance Sampling, by minimizing a weighted version of the empirical risk functional computed from the 'biased' training data Z i with weights Φ(Z i). Although the importance function Φ(z) is generally unknown in practice, we show that, in various situations frequently encountered in practice, it takes a simple form and can be directly estimated from the Z i 's and some auxiliary information on the statistical population P. By means of linearization techniques, we then prove that the generalization capacity of the approach aforementioned is preserved when plugging the resulting estimates of the Φ(Z i)'s into the weighted empirical risk. Beyond these theoretical guarantees, numerical results provide strong empirical evidence of the relevance of the approach promoted in this article.
• A lightweight ECC-based authentication scheme for Internet of Things (IoT)
  
  • Hammi Badis
  • Fayad Achraf
  • Khatoun Rida
  • Zeadally Sherali
  IEEE Systems Journal, IEEE, 2020. (10.1109/JSYST.2020.2970167)
  DOI : 10.1109/JSYST.2020.2970167
• Discrete and stochastic coalitional storage games
  
  • Kiedanski Diego
  • Orda Ariel
  • Kofman Daniel
  , 2020. To achieve a fully decarbonized power grid, a massive deployment of renewable energy resources will be needed, but because of the intermittent nature of their generation, their full potential will not be unleashed unless demand side flexibility plays a bigger role than today. Introducing energy storage at the residential level enables increasing load flexibility, as it allows end-customers to easily change their consumption profile and adapt to the grid requirements. As of today, energy storage for residential consumers represents a considerable investment that is not guaranteed to be profitable. Shared investment models in which a group of consumers jointly acquires energy storage have been proposed in the literature to increase the attractiveness of these devices. Such models naturally employ concepts of cooperative game theory. In this paper, we extend the state-of-the-art cooperative game for modeling the shared investment in storage by adding two crucial extensions: stochasticity of the load and discreetness of the storage device capacity. As our goal is to increase storage capacity in the grid, the number of devices that would be acquired by a group of players that cooperate according to our proposed scheme is compared to the number of devices that would be bought by consumers acting individually. Under the same criteria of customer profitability , simulations using real data reveal that our proposed scheme can increase the deployed storage capacity between 100% and 250%. (10.1145/3396851.3397729)
  DOI : 10.1145/3396851.3397729
• Minimal linear codes from characteristic functions
  
  • Mesnager Sihem
  • Qi Y.
  • Ru H.
  • Tang C.
  IEEE Transactions on Information Theory, Institute of Electrical and Electronics Engineers, 2020.
• From Interferometric to Tomographic Synthetic Aperture Radar. Scatterer unmixing in urban areas: A review of synthetic aperture radar tomography-processing techniques
  
  • Rambour Clement
  • Budillon Alessandra
  • Johnsy Angel
  • Denis Loïc
  • Tupin Florence
  • Schirinzi Gilda
  IEEE geoscience and remote sensing magazine, IEEE, 2020, 8 (2).
• La transmission « naturelle » des savoirs
  
  • Dessalles Jean-Louis
  , 2020, pp.49-58. Les sociétés de chasseurs-cueilleurs n'ont pas d'écoles. Elles accumulent pourtant des savoirs, elles possèdent des langues et des cultures sophistiquées. Si l'on compare notre espèce aux autres primates, tout est différent. Les cultures animales existent, mais elles sont si restreintes qu'elles sont longtemps passées inaperçues aux yeux des éthologues. Pourquoi existe-t-il tant de « savoirs » dans notre espèce ? Et pourquoi les transmettons-nous ? Si la question semble saugrenue, c'est parce que nous avons perdu de vue le caractère apparemment contre-nature de ce comportement. Un comportement contre-nature Les chimpanzés étudiés par l'éthologue Tetsuro Matsuzawa [1994] dans la forêt de Bossou, en Guinée, cassent spontanément des noix très dures en posant la noix sur une pierre (l'enclume) et en frappant avec une autre pierre (le marteau). Leur expertise demande des années d'imitation des congénères. Les jeunes l'acquièrent en explorant un peu au hasard des centaines de combinaisons de paramètres : choix des pierres, position de l'enclume, face et angle de frappe, etc. Les adultes sont très bienveillants vis-à-vis des jeunes qui les observent, mais on ne les voit jamais leur montrer activement le bon geste et encore moins intervenir lorsqu'ils font des erreurs à répétition. L'espèce humaine offre un contraste saisissant. Prenons l'exemple des forums techniques. Imaginons un étudiant qui apprend le langage informatique Python et cherche à savoir comment inverser une liste. Il tape « python reverse list » sur son moteur de recherche et arrive sur un forum comme Stackoverflow. Il constate que sa question a déjà été posée par un autre débutant et qu'elle a obtenu 29 réponses qui ont elles-mêmes reçu 34 commentaires. Les personnes qui ont pris la peine de répondre ne connaissent pas l'étudiant. Elles font partie d'une communauté, celle des programmeurs Python, au sein de laquelle l'entraide spontanée est considérée comme normale. Paru dans : P. Pion & N. Schlanger (Eds.), Apprendre-Archéologie de la transmission des savoirs, pp. 49-58. Paris: La Découverte, 2020.
• « Je dois y aller ». Analyses de séquences de clôtures entre humains et robot
  
  • Licoppe Christian
  • Rollet Nicolas
  Réseaux : communication, technologie, société, Lavoisier, La Découverte, 2020, N°220-221 (2), pp.151. (10.3917/res.220.0151)
  DOI : 10.3917/res.220.0151
• Complexity of voting procedures
  
  • Hudry Olivier
  , 2020.
• The Compared Costs of Domination, Location-Domination and Identification
  
  • Hudry Olivier
  • Lobstein Antoine
  Discussiones Mathematicae Graph Theory, University of Zielona Góra, 2020, 40 (1), pp.127-147. Let G = (V, E) be a finite graph and r ≥ 1 be an integer. For v ∈ V , let B r (v) = {x ∈ V : d(v, x) ≤ r} be the ball of radius r centered at v. A set C ⊆ V is an r-dominating code if for all v ∈ V , we have B r (v) ∩ C = ∅; it is an r-locating-dominating code if for all v ∈ V , we have B r (v) ∩ C = ∅, and for any two distinct non-codewords x ∈ V \ C, y ∈ V \ C, we have B r (x) ∩ C = B r (y) ∩ C; it is an r-identifying code if for all v ∈ V , we have B r (v) ∩ C = ∅, and for any two distinct vertices x ∈ V , y ∈ V , we have B r (x) ∩ C = B r (y) ∩ C. We denote by γ r (G) (respectively, ld r (G) and id r (G)) the smallest possible cardinality of an r-dominating code (respectively, an r-locating-dominating code and an r-identifying code). We study how small and how large the three differences id r (G)−ld r (G), id r (G)−γ r (G) and ld r (G) − γ r (G) can be. (10.7151/dmgt.2129)
  DOI : 10.7151/dmgt.2129
• phiflow: A Differentiable PDE Solving Framework for Deep Learning via Physical Simulations
  
  • Holl Philipp
  • Koltun Vladlen
  • Um Kiwon
  • Thuerey Nils
  , 2020.
• Real-Time Deformation with Coupled Cages and Skeletons
  
  • Corda F
  • Thiery J M
  • Livesu M
  • Puppo E
  • Boubekeur T
  • Scateni R
  Computer Graphics Forum, Wiley, 2020. Skeleton-based and cage-based deformation techniques represent the two most popular approaches to control real-time deformations of digital shapes and are, to a vast extent, complementary to one another. Despite their complementary roles, high-end modelling packages do not allow for seamless integration of such control structures, thus inducing a considerable burden on the user to maintain them synchronized. In this paper, we propose a framework that seamlessly combines rigging skeletons and deformation cages, granting artists with a real-time deformation system that operates using any smooth combination of the two approaches. By coupling the deformation spaces of cages and skeletons, we access a much larger space, containing poses that are impossible to obtain by acting solely on a skeleton or a cage. Our method is oblivious to the specific techniques used to perform skinning and cage-based deformation, securing it compatible with pre-existing tools. We demonstrate the usefulness of our hybrid approach on a variety of examples. (10.1111/cgf.13900)
  DOI : 10.1111/cgf.13900
• Donsker's theorem in {Wasserstein}-1 distance
  
  • Coutin Laure
  • Decreusefond Laurent
  Electronic Communications in Probability, Institute of Mathematical Statistics (IMS), 2020, 25, pp.1--13. We compute the Wassertein-1 (or Kantorovitch-Rubinstein) distance between a random walk in $R^d$ and the Brownian motion. The proof is based on a new estimate of the Lipschitz modulus of the solution of the Stein's equation. As an application, we can evaluate the rate of convergence towards the local time at 0 of the Brownian motion. (10.1214/20-ECP308)
  DOI : 10.1214/20-ECP308
• Improving Interpretability for Computer-aided Diagnosis tools on Whole Slide Imaging with Multiple Instance Learning and Gradient-based Explanations
  
  • Pirovano A.
  • Heuberger H.
  • Berlemont S.
  • Ladjal S.
  • Bloch Isabelle
  , 2020, LNCS 12446, pp.43-53.