Publications

2018

• Taking Apart Autoencoders: How do They Encode Geometric Shapes ?
  
  • Newson Alasdair
  • Almansa Andrés
  • Gousseau Yann
  • Ladjal Saïd
  , 2018. We study the precise mechanisms which allow autoencoders to encode and decode a simple geometric shape, the disk. In this carefully controlled setting, we are able to describe the specific form of the optimal solution to the minimisation problem of the training step. We show that the autoencoder indeed approximates this solution during training. Secondly, we identify a clear failure in the generali-sation capacity of the autoencoder, namely its inability to interpolate data. Finally, we explore several regularisation schemes to resolve the generalisation problem. Given the great attention that has been recently given to the generative capacity of neural networks, we believe that studying in depth simple geometric cases sheds some light on the generation process and can provide a minimal requirement experimental setup for more complex architectures.
• Estimation d'un circuit électrique équivalent, à résistances et capacités thermiques, d'un bâtiment pour le contrôle optimal du chauffage du bâtiment
  
  • Nabil Tahar
  • Jicquel Jean-Marc
  • Girard Alexandre
  • Roueff François
  , 2018, pp.https://permalink.orbit.com/RenderStaticFirstPage?XPN=S5GmjW98%252BeXWqxLm4QBXD3fDUqlXTJ5uwQdFuycu4uk%3D%26n%3D1&id=0&base=FAMPAT. The invention relates to a method for determining a thermal model of a building equipped with a heating installation, in particular for energy diagnosis or optimization of the heating of said building, wherein: - An overall energy consumption load curve (CDC) is obtained from at least one energy consumption meter (COC), In predefined time steps, said load curve being capable of containing a consumption payload (Qu) for heating the building by said installation as well as a load for consumption needs not linked to the heating of the building, - And of one or more connected objects associated with respective appliances, which consume energy and are not controlled for a heat supply (ACN), at least one item of information on the switching on or off of said appliances (ACN), And time intervals are detected in the load curve (CDC) during which the connected objects inform of a stop state of the respective apparatuses, in order to obtain a first estimate of said payload (Qu), which makes it possible to iteratively correct the model for its optimization.
• Generalization Bounds for Minimum Volume Set Estimation based on Markovian Data, ISAIM, International Symposium on Artificial Intelligence and Mathematics proceedings, 1-7
  
  • Bertail Patrice
  • Ciołek Gabriela
  • Clémençon Stéphan
  , 2018.
• Ubiquitous Artificial Intelligence and Dynamic Data Streams
  
  • Bifet Albert
  • Read Jesse
  , 2018, pp.1-6.
• Far-from-Equilibrium Route to Superthermal Light in Bimodal Nanolasers
  
  • Marconi Mathias
  • Javaloyes Julien
  • Hamel Philippe
  • Raineri Fabrice
  • Levenson Ariel
  • Yacomotti Alejandro M.
  Physical Review X, American Physical Society, 2018, 8 (1). (10.1103/PhysRevX.8.011013)
  DOI : 10.1103/PhysRevX.8.011013
• Regional Control of Probabilistic Cellular Automata
  
  • Bagnoli Franco
  • Dridi Sara
  • El Yacoubi Samira
  • Rechtman Raul
  , 2018, 11115.
• OP VI–2 Organ-specific integrative exposure assessment for radio-frequency electromagnetic fields: general population exposure and dose contribution of various sources
  
  • van Wei Luuk
  • Liorni I
  • Capstick Myles
  • Thielens Arno
  • Aerts Sam
  • Joseph W.
  • Wiart Joe
  • Cardis Elisabeth
  • Vermeulen Roel
  Occupational & Environmental Medicine, 2018, 75 (1). <p>Background/aim The daily dose of radio-frequency electromagnetic fields (RF-EMF) received by the human body depends on source, use, and body characteristics. We developed a model capable of estimating total RF-EMF dose (J/kg) for 64 body tissues as well as the contribution of specific sources to total dose based on personal characteristics, source characteristics, and scenarios of use.</p> <p> </p> <p>Methods The Integrated Exposure Model (IEM) uses personal characteristics and scenarios of use to estimate daily RF-EMF dose from mobile phones, DECT phones, tablets, body area networks, laptops, on/near body devices, smartwatches, virtual reality headsets, WiFi routers, and far field sources. Specific absorption rates (SAR) in various tissues were calculated for each source using transfer algorithms based on source and body characteristics. These were then adjusted for scenarios of use. Lastly, the model calculated the integrative dose from all sources combined and the relative contribution of each source. To estimate population exposure levels, we used data from an online survey on use of mobile communication devices deployed in four countries (France, the Netherlands, Spain, Switzerland).</p> <p> </p> <p>Results The online survey resulted in a dataset of 1768 participants, with a mean age of 52 years. Preliminary results indicate an average whole body dose of 0.15 J/kg per day, and an average whole brain dose of 0.09 J/kg per day. Women tended to have slightly higher doses than men, particularly in the youngest age group, due to higher reported use of mobile phones for voice and data. Source specific contribution varied depending on tissue. For the brain, the highest contribution (32%) came from mobile phones. Phone, tablet, and WiFi use together account for 91% of total brain dose. For the whole body: phone data use, WiFi, tablet, and laptop use accounted for 97% of the average total dose in our population.</p> <p> </p> <p>Conclusion We developed a model capable of estimating integrative RF-EMF dose from both current and novel devices. Using survey data on device use we were able to estimate average whole brain (0.09 J/kg) and average whole body (0.15 J/kg) dose. Device output powers in various scenarios of use were found to strongly influence model results.</p>
• BGP Extended Communities LCAF Type
  
  • Saucez Damien
  • Iannone Luigi
  , 2018.
• Algorithms for concurrent systems
  
  • Kuznetsov Petr
  • Guerraoui Rachid
  , 2018.
• Large-signal capabilities of an optically injection-locked semiconductor laser using gain lever
  
  • Sarraute Jean-Maxime
  • Schires Kevin
  • Larochelle Sophie
  • Grillot Frédéric
  , 2018.
• The relation between MOS and pairwise comparisons and the importance of cross-content comparisons
  
  • Zerman Emin
  • Hulusic Vedad
  • Valenzise Giuseppe
  • Mantiuk Rafał
  • Dufaux Frédéric
  , 2018, 30 (14), pp.1-6. Subjective quality assessment is considered a reliable method for quality assessment of distorted stimuli for several mul-timedia applications. The experimental methods can be broadly categorized into those that rate and rank stimuli. Although ranking directly provides an order of stimuli rather than a continuous measure of quality, the experimental data can be converted using scaling methods into an interval scale, similar to that provided by rating methods. In this paper, we compare the results collected in a rating (mean opinion scores) experiment to the scaled results of a pairwise comparison experiment, the most common ranking method. We find a strong linear relationship between results of both methods, which, however, differs between content. To improve the relationship and unify the scale, we extend the experiment to include cross-content comparisons. We find that the cross-content comparisons reduce the confidence intervals for pairwise comparison results, but also improve the relationship with mean opinion scores. (10.2352/ISSN.2470-1173.2018.14.HVEI-517)
  DOI : 10.2352/ISSN.2470-1173.2018.14.HVEI-517
• Preliminary study of CEDBT and CESM performances using simulated analytical contrast uptakes
  
  • Sanchez de La Rosa Ruben
  • Carton A.-K.
  • Milioni de Carvalho P.
  • Li Z.
  • Muller S.
  • Bloch Isabelle
  , 2018, pp.792-795.
• Computing Contrast on Conceptual Spaces
  
  • Sileno Giovanni
  • Bloch Isabelle
  • Atif Jamal
  • Dessalles Jean-Louis
  , 2018, pp.11-25.
• Adaptive Window Strategy for Topic Modeling in Document Streams
  
  • Murena Pierre-Alexandre
  • Al-Ghossein Marie
  • Abdessalem Talel
  • Cornuéjols Antoine
  , 2018.
• Procédé de détection de défaillances et limitations des capteurs à l'aide des communications Car2X
  
  • Monteuuis Jean-Philippe
  • Mafrica Stefano
  • Labiod Houda
  • Servel Alain
  • Zhang Jun
  , 2018.
• 4 Leaf Clover RenderingImproving Monte Carlo Path Tracing with Double hierarchies and collaborative denoising
  
  • Boubekeur Tamy
  , 2018.
• 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>
• 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
• 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.
• 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
• 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
• 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
• 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