Publications

2020

• The StakeCube blockchain : Instantiation, Evaluation & Applications
  
  • Durand Antoine
  • Hébert Guillaume
  • Toumi Khalifa
  • Memmi Gérard
  • Anceaume Emmanuelle
  , 2020, pp.1-8. Blockchains have seen a recent rise in popularity as a generic solution for trustless distributed applications across a wide range of industries. However, blockchain protocols have faced scalability issues in applications involving a growing number of participants. In this paper we instantiate and evaluate StakeCube, a proposal for a scalable shard-based distributed ledger. We further detail and tune a byzantine agreement algorithm suited for StakeCube's sharding structure, and we experimentally study and asses its performance, especially regarding scalability. We were successfully able to run StakeCube with up to 5000 participants, confirming up to 1100 bytes/s of transaction, with a confirmation time starting at 200 seconds. Finally, we use StakeCube in a large scale energy marketplace application, and show that a node running on a Raspberry Pi Zero is able to handle the load without issues.
• Novel Self-timing Speculative Writing for Unreliable STT-MRAM
  
  • Zhang Meng-Di
  • Cai Hao
  • Naviner Lirida
  , 2020, pp.1-3. Considering the insatiable demand for emerging embedded non-volatile memory (NVM), spin-transfer torque magnetic random access memory (STT-MRAM) can be configured with high access speed, readily hybrid integration and guaranteed endurance/retention, which becomes one of the most promising candidates among different types of NVM. However, the major drawback of STT-MRAM is that high switching energy is required, accompanied with unreliable writing operation. In this work, we propose a speculative MRAM writing scheme using self-timing implementation, including speculative/ deterministic write operation and a judgment mechanism. Simulation results show that the speculative scheme can achieve 40% less writing power consumption and 50% less latency during write operation compared to standard writing method. The bit-error rate (BER) is maintained at 10 -9 without inevitable cost. (10.1109/ICSICT49897.2020.9278373)
  DOI : 10.1109/ICSICT49897.2020.9278373
• Extreme events in quantum cascade lasers
  
  • Spitz Olivier
  • Wu Jiagui
  • Herdt Andreas
  • Maisons Grégory
  • Carras Mathieu
  • Elsässer Wolfgang
  • Wong Chee-Wei
  • Grillot Frédéric
  Advanced Photonics, 2020, 2 (06). We demonstrate experimentally that mid-infrared quantum cascade lasers (QCLs) operating under external optical feedback exhibit extreme pulses. These events can be triggered by adding small amplitude periodic modulation, with the highest success rate for the case of a pulse-up excitation. These findings broaden the potential applications for QCLs, which have already been proven to be a semiconductor laser of interest for spectroscopic applications and countermeasure systems. The ability to trigger extreme events paves the way for optical neuron-like systems where information propagates as a result of high intensity bursts. (10.1117/1.AP.2.6.066001])
  DOI : 10.1117/1.AP.2.6.066001]
• Cross-PUF Attacks on Arbiter-PUFs through their Power Side-Channel
  
  • Kroeger Trevor
  • Cheng Wei
  • Guilley Sylvain
  • Danger Jean-Luc
  • Karimi Naghmeh
  , 2020, pp.1-5. (10.1109/ITC44778.2020.9325241)
  DOI : 10.1109/ITC44778.2020.9325241
• New results on approximate Hilbert pairs of wavelet filters with common factors
  
  • Achard Sophie
  • Clausel Marianne
  • Gannaz Irène
  • Roueff François
  Applied and Computational Harmonic Analysis, Elsevier, 2020, 49 (3), pp.1025-1045. In this paper, we consider the design of wavelet filters based on the Thiran common-factor approach proposed in Selesnick [2001]. This approach aims at building finite impulse response filters of a Hilbert-pair of wavelets serving as real and imaginary part of a complex wavelet. Unfortunately it is not possible to construct wavelets which are both finitely supported and analytic. The wavelet filters constructed using the common-factor approach are then approximately analytic. Thus, it is of interest to control their analyticity. The purpose of this paper is to first provide precise and explicit expressions as well as easily exploitable bounds for quantifying the analytic approximation of this complex wavelet. Then, we prove the existence of such filters enjoying the classical perfect reconstruction conditions, with arbitrarily many vanishing moments. (10.1016/j.acha.2019.06.001)
  DOI : 10.1016/j.acha.2019.06.001
• The importance of fillers for text representations of speech transcripts
  
  • Dinkar Tanvi
  • Colombo Pierre
  • Labeau Matthieu
  • Clavel Chloé
  , 2020, pp.7985-7993. While being an essential component of spoken language, fillers (e.g. "um" or "uh") often remain overlooked in Spoken Language Understanding (SLU) tasks. We explore the possibility of representing them with deep contextualised embeddings, showing improvements on modelling spoken language and two downstream tasks-predicting a speaker's stance and expressed confidence. (10.18653/v1/2020.emnlp-main.641)
  DOI : 10.18653/v1/2020.emnlp-main.641
• Hierarchical Pre-training for Sequence Labelling in Spoken Dialog
  
  • Chapuis Emile
  • Colombo Pierre
  • Manica Matteo
  • Labeau Matthieu
  • Clavel Chloé
  , 2020, pp.2636-2648. Sequence labelling tasks like Dialog Act and Emotion/Sentiment identification are a key component of spoken dialog systems. In this work, we propose a new approach to learn generic representations adapted to spoken dialog, which we evaluate on a new benchmark we call Sequence labellIng evaLuatIon benChmark fOr spoken laNguagE benchmark (SILICONE). SILICONE is model-agnostic and contains 10 different datasets of various sizes. We obtain our representations with a hierarchical encoder based on transformer architectures, for which we extend two well-known pre-training objectives. Pre-training is performed on OpenSubtitles: a large corpus of spoken dialog containing over 2.3 billion of tokens. We demonstrate how hierarchical encoders achieve competitive results with consistently fewer parameters compared to state-of-the-art models and we show their importance for both pre-training and fine-tuning. (10.18653/v1/2020.findings-emnlp.239)
  DOI : 10.18653/v1/2020.findings-emnlp.239
• On the power of template attacks in highly multivariate context
  
  • Ouladj Maamar
  • El Mrabet Nadia
  • Guilley Sylvain
  • Guillot Philippe
  • Millérioux Gilles
  Journal of Cryptographic Engineering, Springer, 2020, 10 (4), pp.337-354. When implemented in software (or hardware), a cryptographic protocol can leak sensitive information during its execution. Side-channel attacks can use those leakages in order to reveal some information about the secret used by the algorithm. The leaking side-channel information can take place in many time samples. Measurement appliances can cope with the acquisition of multiple samples. From an adversarial point of view, it is therefore beneficial to attempt to make the most of highly multivariate traces. On the one hand, template attacks have been introduced to deal with multivariate leakages, with as few assumptions as possible on the leakage model. On the other hand, many works have underlined the need for dimensionality reduction. In this paper, we clarify the relationship between template attacks in full space and in linear subspaces, in terms of success rate. In particular, we exhibit a clear mathematical expression for template attacks, which enables an efficient computation even on large dimensions such as several hundred of samples. It is noteworthy that both of PoI-based and PCA-based template attacks can straightforwardly benefit from our approach. Furthermore, we extend the approach to the masking-based protected implementations. Our approach is validated both by simulated and real-world traces. (10.1007/s13389-020-00239-2)
  DOI : 10.1007/s13389-020-00239-2
• Distributed Hypothesis Testing With Variable-Length Coding
  
  • Salehkalaibar Sadaf
  • Wigger Michèle
  IEEE Journal on Selected Areas in Information Theory, IEEE, 2020, 1 (3), pp.681-694. The problem of distributed testing against independence with variable-length coding is considered when the average and not the maximum communication load is constrained as in previous works. The paper characterizes the optimum type-II error exponent of a single-sensor single-decision center system given a maximum type-I error probability when communication is either over a noise-free rate-R link or over a noisy discrete memoryless channel (DMC) with stop-feedback. Specifically, let E denote the maximum allowed type-I error probability. Then the optimum exponent of the system with a rate-R link under a constraint on the average communication load coincides with the optimum exponent of such a system with a rate R/(1-ε) link under a maximum communication load constraint. A strong converse thus does not hold under an average communication load constraint. A similar observation also holds for testing against independence over DMCs. With variable-length coding and stopfeedback and under an average communication load constraint, the optimum type-II error exponent over a DMC of capacity C equals the optimum exponent under fixed-length coding and a maximum communication load constraint when communication is over a DMC of capacity C/(1 - ε). (10.1109/JSAIT.2020.3039839)
  DOI : 10.1109/JSAIT.2020.3039839
• Side-Crossing Menus: Enabling Large Sets of Gestures for Small Surfaces
  
  • Fruchard Bruno
  • Lecolinet Eric
  • Chapuis Olivier
  Proceedings of the ACM on Human-Computer Interaction, Association for Computing Machinery (ACM), 2020, 4 (ISS), pp.189:1 -- 189:19. Supporting many gestures on small surfaces allows users to interact remotely with complex environments such as smart homes, large remote displays, or virtual reality environments, and switching between them (e.g., AR setup in a smart home). Providing eyes-free gestures in these contexts is important as this avoids disrupting the user's visual attention. However, very few techniques enable large sets of commands on small wearable devices supporting the user's mobility and even less provide eyes-free interaction. We present Side-Crossing Menus (SCM), a gestural technique enabling large sets of gestures on a smartwatch. Contrary to most gestural techniques, SCM relies on broad and shallow menus that favor small and rapid gestures. We demonstrate with a first experiment that users can efficiently perform these gestures eyes-free aided with tactile cues; 95% accuracy after training 20 minutes on a representative set of 30 gestures among 172. In a second experiment, we focus on the learning of SCM gestures and do not observe significant differences with conventional Multi-stroke Marking Menus in gesture accuracy and recall rate. As both techniques utilize contrasting menu structures, our results indicate that SCM is a compelling alternative for enhancing the input capabilities of small surfaces. (10.1145/3427317)
  DOI : 10.1145/3427317
• Learning Kolmogorov Models for Binary Random Variables
  
  • Ghauch Hadi
  • Ghadikolaei Hossein Shokri
  • Skoglund Mikael
  • Fischione Carlo
  , 2020, pp.1204-1209. (10.1109/IEEECONF51394.2020.9443570)
  DOI : 10.1109/IEEECONF51394.2020.9443570
• Dynamic Pricing of New Products in Competitive Markets: A Mean-Field Game Approach
  
  • Chenavaz Régis
  • Paraschiv Corina
  • Turinici Gabriel
  Dynamic Games and Applications, Springer Verlag, 2020, 10. Dynamic pricing of new products has been extensively studied in monopolistic and oligopolistic markets. But, the optimal control and differential game tools used to investigate the pricing behavior on markets with a finite number of firms are not well-suited to model competitive markets with an infinity of firms. Using a mean-field games approach, this paper examines dynamic pricing policies in competitive markets, where no firm exerts market power. The theoretical setting is based on a diffusion modeì a la Bass. We prove both the existence and the uniqueness of a mean-field game equilibrium, and we investigate mean tendencies and firms dispersion in the market. Numerical simulations show that the competitive market splits into two separate groups of firms depending on their production experience. The two groups differ in price and profit. Thus, high prices and profits do not have to signal anticompetitive practices, stimulating the debate on market regulation. (10.1007/s13235-020-00369-6)
  DOI : 10.1007/s13235-020-00369-6
• Topological Graph Convolutional Network-Based Urban Traffic Flow and Density Prediction
  
  • Qiu Han
  • Zheng Qinkai
  • Msahli Mounira
  • Memmi Gerard
  • Qiu Meikang
  • Lu Jialiang
  IEEE Transactions on Intelligent Transportation Systems, IEEE, 2020, pp.1-10. (10.1109/TITS.2020.3032882)
  DOI : 10.1109/TITS.2020.3032882
• Musical genre descriptor for classification based on Tonnetz trajectories
  
  • Karystinaios Emmanouil
  • Guichaoua Corentin
  • Andreatta Moreno
  • Bigo Louis
  • Bloch Isabelle
  , 2020. Dans cet article, nous présentons un nouveau descripteur pour la classification automatique du style musical. Notre méthode consiste à définir une trajectoire harmonique dans un espace géométrique, le Tonnetz, puis à la résumer à ses valeurs de centralité, qui constituent les descripteurs. Ceux-ci, associés à des descripteurs classiques, sont utilisés comme caractéristiques pour la classification. Les résultats montrent des scores F 1 supérieurs à 0,8 avec une méthode classique de forêts aléatoires pour 8 classes (une par compositeur), et supérieurs à 0,9 pour une classification en 4 classes de style ou période de composition.
• Impact de l'environnement atmosphérique sur les liaisons optiques sans fil pour la ville du futur
  
  • Sauvage Chloé
  , 2020. Les liens de télécommunications optiques en espace libre sont amenés à se répandre. En particulier car leur déploiement est simple, rapide et économique au contraire des réseaux fibrés. Néanmoins leur fragilité face aux faibles visibilités et au-delà de quelques kilomètres de portée freine leur utilisation. Connaître plus finement le canal atmosphérique urbain sous toutes conditions météorologiques est donc nécessaire afin d’apporter les solutions pour fiabiliser ce type de liaison, notamment avec le choix d’une longueur d’onde adaptée. La première partie de cette thèse introduit le fonctionnement des liens de télécommunications optiques expérimentaux et décrit les différents phénomènes atmosphériques, tel que l’atténuation et la turbulence, auxquels sont soumis les faisceaux laser se propageant sur plusieurs kilomètres en espace libre. La seconde partie présente deux études, pour la première j’ai modélisé un lien optique afin de déterminer sa disponibilité en fonction de différentes longueurs d’onde et conditions atmosphériques. Dans la seconde étude j’ai déterminé, à l’aide de mesures réelles, l’évolution temporelle du canal atmosphérique en présence de turbulence. La troisième partie valide la méthode de reconstruction du Cn², distribué le long du canal turbulent. La dernière partie de cette thèse porte sur le travail préparatoire d’un lien expérimental à λ = 4 µm qui permettra de relier la performance télécom et l’état du canal, en terme de turbulence, caractérisée par de la constante de l’indice de réfraction, Cn². L’ensemble de ces travaux constitue une première étape dans la mise en œuvre de liens de télécommunications optiques en espace libre fonctionnant sous toutes conditions météorologiques.
• Multimodal Groups' Analysis for Automated Cohesion Estimation
  
  • Maman Lucien
  , 2020, pp.713-717. (10.1145/3382507.3421153)
  DOI : 10.1145/3382507.3421153
• Toward a Semantic Representation of the Joconde Database
  
  • Moissinac Jean-Claude
  • Rouzé François
  • Wadhera Piyush
  • Germain Bastien
  , 2020. The Joconde database is a French database, which describes about 600,000 works from French art collections. In the Data&Musée project, we process data from museums and monuments. We have chosen to model the data using a knowledge graph approach. We enrich the data of the project partners with data from other sources. In this article, we present the semantic representation that we have adopted for the Joconde database and the methods used to obtain this representation. Our semantic representation of the Joconde database is available as Open data as the SemJoconde dataset. We believe that the SemJoconde data can become useful references for work on the use of semantic techniques in the cultural field.
• IEEE VIS Workshop on Data Vis Activities to Facilitate Learning, Reflecting, Discussing, and Designing
  
  • Huron Samuel
  • Bach Benjamin
  • Hinrichs Uta
  • Keck Mandy
  • Roberts Jonathan C
  , 2020. This workshop focuses on 'data-visualization activities', especially methods and challenges for teaching and engaging with data visual-ization concepts, knowledge, and practices. For example, sketching aids designers to consider alternative ideas; manipulating tokens help students conceptualize quantities for data visualization; user interviews and discussions help developers understand requirements. Workshops, classes, or collaborations with domain experts, often include hands-on data visualization activities that involve analog or digital tools and materials and more or less well defined protocols. Recent years have seen the emergence of such data visualization activities in different contexts, including education, visualization design, activism, self-reflection, and interdisciplinary collaboration. However, the broad range of contexts and target audiences that Data-Vis activities have been applied to makes it difficult to collect and identify commonalities and build knowledge in a systematic way. Thus, the goals of this workshop are i) start building an understanding and to synthesize protocols and materials used to lead data vis activities, ii) to bring together researchers, practitioners, and educators from within and outside of the visualization community, iii) brainstorm, design, experience, and try novel activities, and to iv) discuss issues around goals, methods, audiences, materials, and evaluation for teaching data visualization.
• Modeling Dynamics of Task and Social Cohesion from the Group Perspective Using Nonverbal Motion Capture-based Features
  
  • Walocha Fabian
  • Maman Lucien
  • Chetouani Mohamed
  • Varni Giovanna
  , 2020, Companion Publication of the 2020 22th ACM International Conference on Multimodal Interaction (ICMI), pp.182-190. (10.1145/3395035.3425963)
  DOI : 10.1145/3395035.3425963
• The WoNoWa Dataset: Investigating the Transactive Memory System in Small Group Interactions
  
  • Biancardi Beatrice
  • Maisonnave-Couterou Lou
  • Renault Pierrick
  • Ravenet Brian
  • Mancini Maurizio
  • Varni Giovanna
  , 2020, pp.528-537. (10.1145/3382507.3418843)
  DOI : 10.1145/3382507.3418843
• HRI-RNN: A User-Robot Dynamics-Oriented RNN for Engagement Decrease Detection
  
  • Atamna Asma
  • Clavel Chloé
  , 2020. Natural and fluid human-robot interaction (HRI) systems rely on the robot's ability to accurately assess the user's engagement in the interaction. Current HRI systems for engagement analysis , and more broadly emotion recognition, only consider user data while discarding robot data which, in many cases, affects the user state. We present a novel recurrent neural architecture for online detection of user engagement decrease in a spontaneous HRI setting that exploits the robot data. Our architecture models the user as a distinct party in the conversation and uses the robot data as contextual information to help assess engagement. We evaluate our approach on a real-world highly imbal-anced data set, where we observe up to 2.13% increase in F1 score compared to a standard gated recurrent unit (GRU).
• Rényi Entropy Power and Normal Transport
  
  • Rioul Olivier
  , 2020. A framework for deriving Rényi entropy-power inequalities (REPIs) is presented that uses linearization and an inequality of Dembo, Cover, and Thomas. Simple arguments are given to recover the previously known Rényi EPIs and derive new ones, by unifying a multiplicative form with constant c and a modification with exponent α of previous works. An information-theoretic proof of the Dembo-Cover-Thomas inequality-equivalent to Young's convolutional inequality with optimal constants-is provided, based on properties of Rényi conditional and relative entropies and using transportation arguments from Gaussian densities. For log-concave densities, a transportation proof of a sharp varentropy bound is presented. This work was partially presented at the 2019 Information Theory and Applications Workshop, San Diego, CA.
• COOB: Hybrid secure device pairing scheme in a hostile environment
  
  • Leneutre Jean
  • Khalfaoui Sameh
  • Villard Arthur
  • Ma Xingjuan
  , 2020.
• Diffusional Side-channel Leakage from Unrolled Lightweight Block Ciphers: A Case Study of Power Analysis on PRINCE
  
  • Yli-Mayry Ville
  • Ueno Rei
  • Miura Noriyuki
  • Nagata Makoto
  • Bhasin Shivam
  • Mathieu Yves
  • Graba Tarik
  • Danger Jean-Luc
  • Homma Naofumi
  IEEE Transactions on Information Forensics and Security, Institute of Electrical and Electronics Engineers, 2020, pp.1-1. (10.1109/TIFS.2020.3033441)
  DOI : 10.1109/TIFS.2020.3033441
• Locating-Domination and Identification
  
  • Lobstein Antoine
  • Hudry Olivier
  • Charon Irène
  , 2020, pp.251-299. Locating-domination and identification are two particular, related, types of domination: a set C of vertices in a graph G = (V, E) is a locating-dominating code if it is dominating and any two vertices of V \ C are dominated by distinct sets of codewords; C is an identifying code if it is dominating and any two vertices of V are dominated by distinct sets of codewords. This chapter presents a survey of the major results on locating-domination and on identification. (10.1007/978-3-030-51117-3_8)
  DOI : 10.1007/978-3-030-51117-3_8