Publications

2018

• Attribute‐based broadcast encryption scheme for lightweight devices
  
  • Canard Sébastien
  • Hieu Phan Duong
  • Trinh Viet Cuong
  IET Information Security, Institution of Engineering and Technology, 2018, 12 (1), pp.52-59. (10.1049/iet-ifs.2017.0157)
  DOI : 10.1049/iet-ifs.2017.0157
• Blind separation of a large number of sparse sources
  
  • Kervazo C.
  • Bobin Jerome
  • Chenot C.
  Signal Processing, Elsevier, 2018, 150, pp.157-165. Blind Source Separation (BSS) is one of the major tools to analyze multi-spectral data with applications that range from astronomical to biomedical signal processing. Nevertheless, most BSS methods fail when the number of sources becomes large, typically exceeding a few tens. Since the ability to estimate large number of sources is paramount in a very wide range of applications, we introduce a new algorithm, coined block-Generalized Morphological Component Analysis (bGMCA) to specifically tackle sparse BSS problems when large number of sources need to be estimated. Sparse BSS being a challenging nonconvex inverse problem in nature, the role played by the algorithmic strategy is central, especially when many sources have to be estimated. For that purpose, the bGMCA algorithm builds upon block-coordinate descent with intermediate size blocks. Numerical experiments are provided that show the robustness of the bGMCA algorithm when the sources are numerous. Comparisons have been carried out on realistic simulations of spectroscopic data. (10.1016/j.sigpro.2018.04.006)
  DOI : 10.1016/j.sigpro.2018.04.006
• Complexity of the computation of dominating sets in graphs
  
  • Hudry Olivier
  , 2018.
• Mathématiques à/en portée
  
  • Zayana Karim
  Au fil des maths, APMEP, 2018. Le langage mathématique et le langage musical ont de particulier que les mots, les signes, les symboles, n'y désignent pas seulement des objets : ils les incarnent [1]. Mieux : mathématiques et musique se parlent et se comprennent, au point que leur dialogue fut souvent fructueux : l'étude méthodique du monocorde, attribuée à Pythagore ; la pratique, en amateur, de la guitare par Zorn ; l'usage des probabilités par Xénakis ; l'emploi des transformations géométriques par Bach en sont autant d'exemples. Et si les deux disciplines ont leur grammaire, axiomes et théorèmes dans un cas, solfège et harmonie dans l'autre, elles ne se renouvellent que parce qu'elles savent perpétuellement réinventer et dépasser leurs règles. En voici un aperçu, à la portée du collégien. Par Karim Zayana, inspecteur général, professeur invité à Télécom Paristech.. La portée mathématique du langage musical Quand on lit de la musique, on fait déjà, sans le savoir des mathématiques. Une portée, c'est un axe horizontal-axe des temps, et un axe vertical-axe des notes, lesquelles notes sont indissociablement liées à des fréquences, et donc des nombres. Ajoutons une origine, marquée par la clé qui sert de référence, figure 1. Petit raffinement : l'axe vertical n'est, en vérité, pas gradué linéairement mais logarithmiquement. Quand on franchit un barreau, du DO au RÉ par exemple, on multiplie en fait la fréquence par à peu près 9 8 ⁄. Et quand on passe d'un MI au FA, on la multiplie à peu près par la racine carrée de ce nombre, √ 9 8 ⁄ = 3 2√2 ⁄. Autre fait remarquable : nous venons de décrire ce qui s'apparente à la représentation graphique d'une fonction telle que nous la rencontrons communément aujourd'hui. En cela, la musique avait quelques siècles d'avance sur les mathématiques, qui n'ont adopté ce mode d'explicitation qu'au XVII e siècle. Une portée musicale, nous l'avons dit, c'est un repère. Et la géométrie s'invite dès lors spontanément. On va reconnaître, sur certaines partitions, les effets de transformations du plan : translations et symétries ou association des deux. La translation horizontale traduit un décalage temporel, qu'on retrouve dans l'écriture du canon. La translation verticale est, elle, plus ou moins une transposition, c'est-à-dire que l'on Figure 1 Figure 2
• Phase evolution of the direct detection noise figure of a nondegenerate fiber phase-sensitive amplifier
  
  • Labidi Tarek
  • Fsaifes Ihsan
  • Xie Weilin
  • Chatterjee Debanuj
  • Goldfarb Fabienne
  • Bretenaker Fabien
  Optics Letters, Optical Society of America - OSA Publishing, 2018, 43 (18), pp.4546. We experimentally investigate the evolution of the direct detection noise figure of a nondegenerate phase-sensitive amplifier based on a nonlinear fiber, as a function of the relative phase between the signal, idler, and pump, all other parameters remaining fixed. The use of a fiber with a high stimulated Brillouin scattering threshold permits us to investigate the full range of phase-sensitive gain and noise figure without pump dithering. Good agreement is found with theory, both for signal only and combined signal and idler direct detections. (10.1364/OL.43.004546)
  DOI : 10.1364/OL.43.004546
• Open data in the hotel industry: leveraging forthcoming events for hotel recommendation
  
  • Al-Ghossein Marie
  • Abdessalem Talel
  • Barré Anthony
  Information Technology \& Tourism, 2018.
• Experimental investigation of practical unforgeable quantum money
  
  • Bozzio Mathieu
  • Orieux Adeline
  • Trigo Vidarte Luis
  • Zaquine Isabelle
  • Kerenidis Iordanis
  • Diamanti Eleni
  npj Quantum Information, Nature, 2018, 4 (1). Wiesner's unforgeable quantum money scheme is widely celebrated as the first quantum information application. Based on the no-cloning property of quantum mechanics, this scheme allows for the creation of credit cards used in authenticated transactions offering security guarantees impossible to achieve by classical means. However, despite its central role in quantum cryptography, its experimental implementation has remained elusive because of the lack of quantum memories and of practical verification techniques. Here, we experimentally implement a quantum money protocol relying on classical verification that rigorously satises the security condition for unforgeability. Our system exploits polarization encoding of weak coherent states of light and operates under conditions that ensure compatibility with state-of-the-art quantum memories. We derive working regimes for our system using a security analysis taking into account all practical imperfections. Our results constitute a major step towards a real-world realization of this milestone protocol. (10.1038/s41534-018-0058-2)
  DOI : 10.1038/s41534-018-0058-2
• Incidence of paradoxical reactions in patients treated with tocilizumab for rheumatoid arthritis: Data from the French registry REGATE
  
  • Terreaux William
  • Masson Claire
  • Eschard Jean-Paul
  • Bardin Thomas
  • Constantin Arnaud
  • Le Dantec Loïc
  • Marcelli Christian
  • Perdriger Aleth
  • Scotto Di Fazano Claire
  • Wendling Daniel
  • Sibilia Jean
  • Morel Jacques
  • Salmon Jean
  Joint Bone Spine, Elsevier Masson, 2018, 85 (1), pp.53-57. Objectives Assess the frequency of paradoxical reactions encountered in daily practice under tocilizumab, using the REGATE (Registry-RoActemra) registry. The secondary objectives were to determine the type of paradoxical reaction and the consequences of these reactions. Methods The REGATE registry is an independent prospective registry, promoted by the French Society of Rheumatology, consisting of patients treated with tocilizumab for rheumatoid arthritis. The paradoxical reaction was retained if it was a paradoxical precipitation of a condition for which tocilizumab was indicated, if tocilizumab was being used for an alternative indication, and if it appeared after at least one tocilizumab infusion. Results Among the 1491 patients included with at least one follow-up visit (3429 patient-years), a paradoxical reaction occurred in 9 patients (0.60% of patients; 2.62/1000 patient-years). These were 7 de novo pathologies (3 vasculitis, 3 uveitis, 1 lupus) and 2 exacerbations of pre-existing conditions (1 vasculitis, 1 lupus). Permanent discontinuation of tocilizumab was chosen for 5 patients. Conclusions In the REGATE registry, the occurrence of paradoxical reactions in patients treated with tocilizumab was rare. (10.1016/j.jbspin.2017.01.002)
  DOI : 10.1016/j.jbspin.2017.01.002
• Shannon et la théorie de l'information
  
  • Rioul Olivier
  , 2018. Analyse de la publication de C.E. Shannon, &quot;A mathematical Theory of Communication&quot;, The Bell System Technical Journal, Vol. 27, pp. 379–423, 623-656, July, October, 1948 (55 pages)</p> Dans ce texte fondateur de la théorie de l’information, Shannon définit la notion de communication, la fonde sur celle de probabilité, définit le terme bit comme mesure logarithmique de l’information, ainsi que la notion d’entropie informatique (par analogie avec celle de Boltzmann en physique statistique). Il définit aussi mathématiquement la capacité d’un canal de transmission : on peut transmettre l’information de façon fiable tant que le débit ne dépasse pas cette capacité – le bruit présent dans le canal ne limite pas la qualité de la communication, mais uniquement le débit de transmission.</p>
• Uniformly Projected RCQD QAM: A Low-Complexity Signal Space Diversity Solution over Fading Channels With or Without Erasures
  
  • Arbi Tarak
  • Geller Benoit
  • Yang Jianxiao
  • Abdel Nour Charbel
  • Rioul Olivier
  IEEE Transactions on Broadcasting, Institute of Electrical and Electronics Engineers, 2018. —Rotated and cyclic Q-delayed (RCQD) M-QAM (Quadrature Amplitude Modulation) provides signal space diversity and thus improves system performance over fading channels. However, previously published RCQD solutions were designed without fully considering the high demodulation complexity which prohibits wider applications. In this paper, a complete solution is proposed to reduce complexity for both the modulator and the demodulator. This solution uses a series of rotation angles α =arctan(1/ √ M) which bring many interesting properties to the RCQD signals. A simplified sphere demapping algorithm is derived for fading channels with and without erasure events. In contrast to the sphere-decoder used for MIMO detection, the radius of the proposed sphere-demapper involves an exact amount of constellation points, thereby ensuring to perform the soft demapping operation successfully. Moreover, when either the in-phase (I) or the quadrature component (Q) is erased, the proposed demapping algorithm performs as well as the full-complexity Max-Log algorithm, with a reduced complexity. Compared to the solution currently used in DVB-T2, the proposed method reduces tremendously the computational complexity while still achieving similar performance over fading channels and even better performance over fading erasure channels. (10.1109/TBC.2018.2811618)
  DOI : 10.1109/TBC.2018.2811618
• A Generative Model for Non-Intrusive Load Monitoring in Commercial Buildings
  
  • Henriet Simon
  • Şimşekli Umut
  • Fuentes Benoît
  • Richard Gael
  Energy and Buildings, Elsevier, 2018. In the recent years, there has been an increasing academic and industrial interest for analyzing the electrical consumption of commercial buildings. Whilst having similarities with the Non Intrusive Load Monitoring (NILM) tasks for residential buildings, the nature of the signals that are collected from large commercial buildings introduces additional difficulties to the NILM research causing existing NILM approaches to fail. On the other hand, the amount of publicly available datasets collected from commercial buildings is very limited, which makes the NILM research even more challenging for this type of large buildings. In this study, we aim at addressing these issues. We first present an extensive statistical analysis of both commercial and residential measurements from public and private datasets and show important differences. Secondly, we develop an algorithm for generating synthetic current waveforms. We then demonstrate using real measurement and quantitative metrics that both our device model and our simulations are realistic and can be used to evaluate NILM algorithms. Finally, to encourage research on commercial buildings we release a synthesized dataset.
• The challenge of cerebral magnetic resonance imaging in neonates: A new method using mathematical morphology for the segmentation of structures including diffuse excessive high signal intensities
  
  • Xu Yongchao
  • Morel Baptiste
  • Dahdouh Sonia
  • Puybareau Élodie
  • Virzì Alessio
  • Urien Hélène
  • Géraud Thierry
  • Adamsbaum Catherine
  • Bloch Isabelle
  Medical Image Analysis, Elsevier, 2018, 48, pp.75-94. Preterm birth is a multifactorial condition associated with increased morbidity and mortality. Diffuse excessive high signal intensity (DEHSI) has been recently described on T2-weighted MR sequences in this population and thought to be associated with neuropathologies. To date, no robust and reproducible method to assess the presence of white matter hyperintensities has been developed, perhaps explaining the current controversy over their prognostic value. The aim of this paper is to propose a new semi-automated framework to detect DEHSI on neonatal brain MR images having a particular pattern due to the physiological lack of complete myelination of the white matter. A novel method for semi-automatic segmentation of neonatal brain structures and DEHSI, based on mathematical morphology and on max-tree representations of the images is thus described. It is a mandatory first step to identify and clinically assess homogeneous cohorts of neonates for DEHSI and/or volume of any other segmented structures. Implemented in a user-friendly interface, the method makes it straightforward to select relevant markers of structures to be segmented, and if needed, apply eventually manual corrections. This method responds to the increasing need for providing medical experts with semi-automatic tools for image analysis, and overcomes the limitations of visual analysis alone, prone to subjectivity and variability. Experimental results demonstrate that the method is accurate, with excellent reproducibility and with very few manual corrections needed. Although the method was intended initially for images acquired at 1.5T, which corresponds to usual clinical practice, preliminary results on images acquired at 3T suggest that the proposed approach can be generalized. (10.1016/j.media.2018.05.003)
  DOI : 10.1016/j.media.2018.05.003
• High-speed per-flow software monitoring with limited resources
  
  • Zhang Tianzhu
  • Linguaglossa Leonardo
  • Gallo Massimo
  • Giaccone Paolo
  • Rossi Dario
  , 2018.
• Lecture on Continuous-Variable Quantum Key Distribution
  
  • Alleaume Romain
  , 2018.
• Weakly Supervised Representation Learning for Unsynchronized Audio-Visual Events
  
  • Parekh Sanjeel
  • Essid Slim
  • Ozerov Alexey
  • Duong Ngoc Q K
  • Pérez Patrick
  • Richard Gael
  , 2018. Audiovisual representation learning is an important task from the perspective of designing machines with the ability to understand complex events. To this end, we propose a novel multimodal framework that instantiates multiple instance learning. We show that the learnt representations are useful for classifying events and localizing their characteristic audiovisual elements. The system is trained using only video-level event labels without any timing information. An important feature of our method is its capacity to learn from unsynchronized audiovisual events. We achieve state-of-the-art results on a large-scale dataset of weakly-labeled audio event videos. Visualizations of localized visual regions and audio segments substantiate our system's efficacy, especially when dealing with noisy situations where modality-specific cues appear asynchronously.
• Integral estimation based on Markovian design
  
  • Azaïs Romain
  • Delyon Bernard
  • Portier François
  Advances in Applied Probability, Applied Probability Trust, 2018, 50 (3), pp.833-857. Suppose that a mobile sensor describes a Markovian trajectory in the ambient space. At each time the sensor measures an attribute of interest, e.g., the temperature. Using only the location history of the sensor and the associated measurements, the aim is to estimate the average value of the attribute over the space. In contrast to classical probabilistic integration methods, e.g., Monte Carlo, the proposed approach does not require any knowledge on the distribution of the sensor trajectory. Probabilistic bounds on the convergence rates of the estimator are established. These rates are better than the traditional "root n"-rate, where n is the sample size, attached to other probabilistic integration methods. For finite sample sizes, the good behaviour of the procedure is demonstrated through simulations and an application to the evaluation of the average temperature of oceans is considered. (10.1017/apr.2018.38)
  DOI : 10.1017/apr.2018.38
• Semiconductor quantum dot lasers epitaxially grown on silicon with low linewidth enhancement factor
  
  • Duan J.
  • Huang H.
  • Jung D.
  • Zhang Z.
  • Norman J.
  • Bowers J. E.
  • Grillot F.
  Applied Physics Letters, American Institute of Physics, 2018, 112 (25), pp.251111. This work reports on the ultra-low linewidth enhancement factor (αH-factor) of semiconductor quantum dot lasers epitaxially grown on silicon. Owing to the low density of threading dislocations and resultant high gain, an αH value of 0.13 that is rather independent of the temperature range (288 K–308 K) is measured. Above the laser threshold, the linewidth enhancement factor does not increase extensively with the bias current which is very promising for the realization of future integrated circuits including high performance laser sources. (10.1063/1.5025879)
  DOI : 10.1063/1.5025879
• Nonnegative Matrix Factorization
  
  • Badeau Roland
  • Virtanen Tuomas
  , 2018, pp.131-160.
• Remembered events are unexpected (Commentary on Mahr \& Csibra: Why do we remember? The communicative function of episodic memory)
  
  • Dessalles Jean-Louis
  Behavioral and Brain Sciences, Cambridge University Press (CUP), 2018, 41, pp.22. We remember a small proportion of our experiences as events. Are these events selected because they are useful and can be proven true, or rather because they are unexpected? (10.1017/S0140525X17001315)
  DOI : 10.1017/S0140525X17001315
• Bubbles of Trust: a decentralized Blockchain-based authentication system for IoT
  
  • Hammi Mohamed T.
  • Hammi Badis
  • Bellot Patrick
  • Serhrouchni Ahmed
  Computers & Security, Elsevier, 2018, pp.15. Internet of Things becomes a major part of our lives, billions of autonomous devices are connected and communicate with each other. This revolutionary paradigm creates a new dimension that removes the boundaries between the real and the virtual worlds. The Wireless Sensor Networks are a masterpiece of the success of this technology, using limited capacity sensors and actuators, industrial, medical, agricultural and many other environments can be covered and managed automatically. This autonomous interacting things should authenticate each other, and communicate securely. Otherwise malicious users can cause serious damages on such systems. In this paper we propose a robust, transparent, flexible and energy efficient blockchain-based authentication mechanism called BCTrust, which is designed especially for devices with computational, storage and energy consumption constraints. In order to evaluate our approach, we realized a real implementation with C programming language, and Ethereum Blockchain.
• A Safe Communication Protocol for IoT Devices
  
  • Hammi Mohamed T.
  • Livolant Erwan
  • Bellot Patrick
  • Minet Pascale
  • Serhrouchni Ahmed
  Annals of Telecommunications - annales des télécommunications, Springer, 2018, pp.15. The Internet of Things (IoT) has overturned the information technology world. This new phenomenon is becoming inescapable and already covers almost all fields, from watchmaking to automated factories. IoT simplifies our everyday life and creates value for people and businesses. Things, also called entities, are very heterogeneous, use different communication technologies and, generally, are limited capacity devices. Therefore securing such systems raises many challenges. Communicating entities should authenticate each other and protect the integrity and the confidentiality of the data they exchange while using lightweight, fast and energy-efficient algorithms. In this paper, we propose a robust security protocol, designed especially for constrained IoT devices. We carried out a real implementation and the obtained results prove the efficiency of our protocol.
• «Informathique»
  
  • Zayana Karim
  • Croix Edwige
  Au fil des maths, APMEP, 2018. Essai sur la didactique de l'informatique, en lien avec les mathématiques
• Ultrafast and nonlinear dynamics of InAs/GaAs semiconductor quantum dot lasers
  
  • Grillot Frédéric
  • Arsenijevic Dejan
  • Huang Heming
  • Bimberg Dieter
  , 2018.
• Segmentation of pelvic vessels in pediatric MRI using a patch-based deep learning approach
  
  • Virzi Alessio
  • Gori Pietro
  • Muller Cécile
  • Mille Eva
  • Peyrot Quoc
  • Berteloot Laureline
  • Boddaert Nathalie
  • Sarnacki Sabine
  • Bloch Isabelle
  , 2018, LNCS 11076, pp.97-106. In this paper, we propose a patch-based deep learning ap- proach to segment pelvic vessels in 3D MRI images of pediatric patients. For a given T2 weighted MRI volume, a set of 2D axial patches are extracted using a limited number of user-selected landmarks. In order to take into account the volumetric information, successive 2D axial patches are combined together, producing a set of pseudo RGB color images. These RGB images are then used as input for a convolutional neural network (CNN), pre-trained on the ImageNet dataset, which re- sults into both segmentation and vessel labeling as veins or arteries. The proposed method is evaluated on 35 MRI volumes of pediatric patients, obtaining an average segmentation accuracy in terms of Average Sym- metric Surface Distance of ASSD = 0.89 ± 0.07 mm and Dice Index of DC = 0.79 ± 0.02.
• Practical Random Linear Coding for MultiPath TCP: MPC-TCP
  
  • Paul-Louis Ageneau
  • Boukhatem Nadia
  • Gerla Mario
  , 2018. MPTCP is a TCP extension that enables transparent multipath for multihomed hosts. However, MPTCP is subject to head-of-line blocking, a problem that degrades delay and throughput. This problem is especially critical when used in wireless environments. On wireless, unreliable links, for example, traffic can get stalled on one path, slowing down the entire flow. A related problem is rescheduling the packets in other subflows too early, which could result in increased overhead. Random linear network coding is a potential approach to solve this problem among others, and we choose to focus in its practical capability to attenuate performance drops caused by blocking while guaranteeing full network compatibility. We have developed a version of MPTCP with network coding, MPC-TCP (MultiPath Coded TCP) and implemented it in the Linux kernel. This scheme offers a simple, practical implementation of network coding across subflows, requires minimal changes to MPTCP and preserves the TCP subflows compatibility with middleboxes. We then use our implementation to investigate the network scenarios where efficiency gains are the highest compared to vanilla MPTCP.