Publications

2017

• Inpainting vidéo préservant le mouvement
  
  • Le Thuc Trinh
  • Almansa Andrés
  • Gousseau Yann
  • Masnou Simon
  , 2017.
• Securing PKI Requests for C-ITS systems
  
  • Monteuuis Jean-Philippe
  • Hammi Badis
  • Salles Daniel Eduardo
  • Labiod Houda
  • Blancher Rémi
  • Abalea Erwan
  • Lonc Brigitte
  , 2017. Cooperative Intelligent Transportation Systems are rapidly gaining momentum in the scenario of modern wireless communications. Within these environments, messages are exchanged continuously. The latter should be secure and ensure users’ privacy. Public Key Infrastructures (PKIs) represent the major solution to meet security needs. On the other hand, communications between the PKI and the vehicle stations or the Road Side Unit stations should also be secure. Main current security standards do not address and define a complete detailed secure end-to-end mechanism to send requests to the PKI and receive the associated responses. In this paper, we propose a detailed security protocol, based on ETSI security standards, that ensures confidentiality, integrity and authentication. The evaluation of the latter shows its ability in meeting security needs.
• Localization of multiple jamming attackers in vehicular ad hoc network
  
  • Pang Liang
  • Chen Xio
  • Shi Yong
  • Zhi Xue
  • Khatoun Rida
  International Journal of Distributed Sensor Networks, 2017, 13 (8).
• Massive diversity for 5G and beyond
  
  • Sibille Alain
  , 2017. Radio communications have now widely penetrated both the professional and private spheres, for everyday uses of largely differing importance and criticality that are anticipated to further increase in the coming years through 5G networks and the internet of things. This will address major “vertical” applications such as smart homes and smart cities, agriculture, connected and autonomous vehicles, health, industry and many others. While in some cases the failure of the radio link is tolerable and without serious implications, in others reliability will be critical and unavoidable. Unfortunately, the laws of electromagnetics are such that numerous effects are detrimental to the link budget, are varying and are uneasily controllable. In this context, how to ensure a very high level reliability, which solutions are feasible and up to which degree of complexity? This paper recalls the physical and technical sources of an uncertain reliability for the radio link, in relation with antennas and propagation, and evokes “massive diversity” as a future development to guarantee a constant connectivity service with ultra-high reliability.
• Complex delay dynamics of high power quantum cascade oscillators
  
  • Grillot Frédéric
  • Newell Tim
  • Tom Gavrielides
  • Carras Mathieu
  , 2017.
• Fast Langevin based algorithm for MCMC in high dimensions
  
  • Durmus Alain
  • Roberts Gareth
  • Vilmart Gilles
  • Zygalakis Konstantinos
  The Annals of Applied Probability, Institute of Mathematical Statistics (IMS), 2017, 27 (4), pp.2195 - 2237. We introduce new Gaussian proposals to improve the efficiency of the standard Hastings–Metropolis algorithm in Markov chain Monte Carlo (MCMC) methods, used for the sampling from a target distribution in large dimension d. The improved complexity is O(d1/5) compared to the complexity O(d1/3)O(d1/3) of the standard approach. We prove an asymptotic diffusion limit theorem and show that the relative efficiency of the algorithm can be characterised by its overall acceptance rate (with asymptotical value 0.704), independently of the target distribution. Numerical experiments confirm our theoretical findings. (10.1214/16-AAP1257)
  DOI : 10.1214/16-AAP1257
• Poly-symmetry in processor-sharing systems
  
  • Bonald Thomas
  • Comte Céline
  • Shah Virag
  • de Veciana Gustavo
  Queueing Systems, Springer Verlag, 2017. We consider a system of processor-sharing queues with state-dependent service rates. These are allocated according to balanced fairness within a polymatroid capacity set. Balanced fairness is known to be both insensitive and Pareto-efficient in such systems, which ensures that the performance metrics, when computable, will provide robust insights into the real performance of the system considered. We first show that these performance metrics can be evaluated with a complexity that is polynomial in the system size if the system is partitioned into a finite number of parts, so that queues are exchangeable within each part and asymmetric across different parts. This in turn allows us to derive stochastic bounds for a larger class of systems which satisfy less restrictive symmetry assumptions. These results are applied to practical examples of tree data networks, such as backhaul networks of Internet service providers, and computer clusters. (10.1007/s11134-017-9525-2)
  DOI : 10.1007/s11134-017-9525-2
• Practical implementation of M4 for web visualization service
  
  • Bae Puleum
  • Lim Keun-Woo
  • Jung Woo-Sung
  • Ko Young-Bae
  Journal of Communications and Networks, IEEE & Korea Information and Communications Society, 2017, 19 (4), pp.384-391. Vast volumes of time series are becoming more common in part to recent research advancements in big data analytics and sensor/monitoring networks. However, tranmission of time series for visualization services can cause serious bandwidth wastage and extensive network delays if there is no efficient data management. Existing work such as M4 aim to solve this problem by providing high data reduction rates through data aggregation and guaranteeing the reliability of visualization results at the same time. However, current work on M4 does not consider verification in a more practical environment; for example experimentation on web-based servers that are openly accessible by users. In this paper, we propose inter-pixel gradient-based M4 (IGM4) for enhancing the existing M4 scheme, and conduct a study to reduce the amount of data and delay without distorting the results of visualized graph. We build user-friendly web-based system to dealing with the data processing technique, and perform test on the empirical environment. Finally, we present the results of performance evaluation through comparison among the original data, M4, and IGM4 reflecting the various kinds of time series and resolutions.
• Interaction Techniques Exploiting Memory to Facilitate Command Activation
  
  • Fruchard Bruno
  • Lecolinet Eric
  • Chapuis Olivier
  , 2017, pp.5. L’objectif de cette thèse est de proposer une nouvelle catégorie de techniques interactives reposant sur des méthodes d’augmentation de la mémoire humaine afin de permettre, via des interactions gestuelles, d’accéder facilement et instantanément à un large ensemble de commandes ou de données. Ce projet comporte deux contributions : 1) améliorer la compréhension de certains phénomènes entrant en jeu dans l’apprentissage de gestes et la mémorisation de commandes; 2) proposer de nouvelles techniques d’interaction gestuelle facilitant la mémorisation en s’appuyant sur les résultats précédents et certaines connaissances issues des méthodes mnémotechniques.
• Translation of ATL to AGT and Application to a Code Generator for Simulink
  
  • Richa Elie
  • Borde Etienne
  • Pautet Laurent
  Software and Systems Modeling, Springer Verlag, 2017.
• Fully-Digital Blind Compensation of Non-Linear Distortions in Wideband Receivers
  
  • Vansebrouck Raphaël
  • Jabbour Chadi
  • Jamin Olivier
  • Desgreys Patricia
  Transactions on Circuits and Systems I, 2017, 64 (8), pp.2112-2123. Digital post-distortion is becoming an increasingly attractive solution to compensate for the non-linearities of RF receivers implemented in deep submicron CMOS technologies. A very promising technique which provides flexibility and robustness is the frequency spreading based digital post-distortion. This paper focuses on the analysis of this approach for wideband receivers and its main limitations, such as the anti-alias filter (AAF) impact. As a matter of fact, distortions filtered by the AAF can degrade the correction performance. To overcome this problem, a novel solution based on mimicking the AAF frequency response in the digital domain is proposed. Aspects regarding the estimation and the algorithm convergence are also studied: the noise effect and the choice of the free frequency band. Furthermore, two other techniques are developed to improve the modeling and the correction of the memory effect using, respectively, a bank of filters and two-step architecture. The proposed techniques are demonstrated by simulations and measurements on a multi-channel receiver suited for DVB-T applications. The receiver is based on a 1-GHz bandwidth RF front-end followed by a 2.7-GHz 13-bit analog-to-digital converter.
• Truthfulness of Candidates in Set of t-uples Expansion
  
  • Er Ngurah Agus Sanjaya
  • Ba Mouhamadou Lamine
  • Abdessalem Talel
  • Bressan Stéphane
  , 2017, pp.314-323. The collection and exploitation of ratings from users are modern pillars of collaborative filtering. Likert scale is a psychometric quantifier of ratings popular among the electronic commerce sites. In this paper, we consider the tasks of collecting Likert scale ratings of items and of finding the n-k best-rated items, i.e., the n items that are most likely to be the top-k in a ranking constructed from these ratings. We devise an algorithm, Pundit, that computes the n-k best-rated items. Pundit uses the probability-generating function constructed from the Likert scale responses to avoid the combinatorial exploration of the possible outcomes and to compute the result efficiently. Selection of the best-rated items meets, in practice, the major obstacle of the scarcity of ratings. We propose an approach that learns from the available data how many ratings are enough to meet a prescribed error. We empirically validate with real datasets the effectiveness of our method to recommend the collection of additional ratings. (10.1007/978-3-319-64468-4_24)
  DOI : 10.1007/978-3-319-64468-4_24
• Random Abstract Simplicial Complexes Reduction
  
  • Vergne Anaïs
  • Decreusefond Laurent
  • Martins Philippe
  , 2017. Random abstract simplicial complex representation provides a mathematical description of wireless networks and their topology. In order to reduce the energy consumption in this type of network, we intend to reduce the number of network nodes without modifying neither the connectivity nor the coverage of the network. In this paper, we present a reduction algorithm that lower the number of points of an abstract simplicial complex in an optimal order while maintaining its topology. Then, we study the complexity of such an algorithm for a network simulated by a binomial point process and represented by a Vietoris-Rips complex.
• Technological Impacts in Socio-Technical Communities. Values and Pathologies
  
  • Diaconescu Ada
  • Pitt Jeremy
  IEEE Technology and Society Magazine, Institute of Electrical and Electronics Engineers, 2017.
• A Sparsity-based simplification method for segmentation of spectral domain optical coherence tomography images
  
  • Meiniel William
  • Gan Yu
  • Olivo-Marin J.-C.
  • Angelini Elsa D.
  , 2017, 10394. Optical coherence tomography (OCT) has emerged as a promising image modality to characterize biological tissues. With axio-lateral resolutions at the micron-level, OCT images provide detailed morphological information and enable applications such as optical biopsy and virtual histology for clinical needs. Image enhancement is typically required for morphological segmentation, to improve boundary localization, rather than enrich detailed tissue information. We propose to formulate image enhancement as an image simplification task such that tissue layers are smoothed while contours are enhanced. For this purpose, we exploit a Total Variation sparsity-based image reconstruction, inspired by the Compressed Sensing (CS) theory, but specialized for images with structures arranged in layers. We demonstrate the potential of our approach on OCT human heart and retinal images for layers segmentation. We also compare our image enhancement capabilities to the state-of-the-art denoising techniques. (10.1117/12.2274126)
  DOI : 10.1117/12.2274126
• Long Delay Optical Feedback Sensitivity of Hybrid III-V/SOI Directly Modulated DFB Lasers
  
  • Gallet Antonin
  • Schires Kevin
  • Huang Heming
  • Song Mengdi
  • Accard Alain
  • Maké Dalila
  • Olivier Ségolène
  • Duan G.
  • Grillot Frédéric
  , 2017, pp.ThP.2.
• Opinion Dynamics Modeling for Movie Review Transcripts Classification with Hidden Conditional Random Fields
  
  • Barriere Valentin
  • Clavel Chloé
  • Essid Slim
  , 2017.
• Propagation modelling towards the design of drone-borne GPR for humanitarian applications
  
  • Tanzi Tullio
  • Chandra Madhu
  , 2017.
• Double Hierarchies for Directional Importance Sampling in Monte Carlo Rendering
  
  • Bus Norbert
  • Boubekeur Tamy
  Journal of Computer Graphics Techniques, Williams College, 2017, 6 (3), pp.35-37. We describe a novel representation of the light field tailored to improve importance sampling for Monte Carlo rendering. The domain of the light field i.e., the product space of spatial positions and directions is hierarchically subdivided into subsets on which local models characterize the light transport. The data structure, that is based on double trees, approximates the exact light field and enables very efficient queries for importance sampling and easy tracing of photons in the scene. The framework is simple yet flexible, enabling the usage of any type of local model for representing the light field, provided it can be efficiently importance sampled. The method also supports progressive refinement with an arbitrary number of photons. We provide a reference open source implementation.
• A generic framework for the structured abstraction of images
  
  • Faraj Noura
  • Xia Gui-Song
  • Delon Julie
  • Gousseau Yann
  , 2017. Structural properties are important clues for non-photorealistic representations of digital images. Therefore, image analysis tools have been intensively used either to produce stroke-based renderings or to yield abstractions of images. In this work, we propose to use a hierarchical and geometrical image representation, called a topographic map, made of shapes organized in a tree structure. There are two main advantages of this analysis tool. Firstly, it is able to deal with all scales, so that every shape of the input image is represented. Secondly, it accounts for the inclusion properties within the image. By iteratively performing simple local operations on the shapes (removal, rotation, scaling, replacement...), we are able to generate abstract renderings of digital photographs ranging from geometrical abstraction and painting-like effects to style transfer, using the same framework. In particular, results show that it is possible to create abstract images evoking Malevitch’s Suprematist school, while remaining grounded in the structure of digital images, by replacing all the shapes in the tree by simple geometric shapes. (10.1145/3092919.3092930)
  DOI : 10.1145/3092919.3092930
• Statistical Methods Applied to CMOS Reliability Analysis -A Survey
  
  • Cai Hao
  • Naviner Jean-François
  • Petit Hervé
  , 2017. The design of integrated circuits (ICs) and systems in sub-90nm CMOS technology is very challenging~\cite{ITRS}. The scaling down of technology not only caused an unbalanced relationship between supply voltage and transistor threshold voltage ($V_{th}$), but also induced ageing effects and variability problems. In semiconductor manufacturing, systematic and random variations exist during different fabrication steps. Moreover, once ICs are fully functional, both ageing and variability degrade ICs performance and lead to uncertainty performance distribution. In this paper, we analysis process variations based on BSIM4 transistor model.
• Conversational topic connectedness predicted by Simplicity Theory
  
  • Dessalles Jean-Louis
  , 2017, pp.1914-1919. People avoid changing subject abruptly during conversation. There are reasons to think that this constraint is more than a social convention and is deeply rooted in our cognition. We show here that the phenomenon of topic connectedness is an expected consequence of the maximization of unexpectedness and that it is predicted by Simplicity Theory.
• Influence of fibre homogeneity on Four Wave Mixing pair generation
  
  • Harlé Thibault
  • Barbier Margaux
  • Cordier Martin
  • Orieux Adeline
  • Diamanti Eleni
  • Zaquine Isabelle
  • Delaye Philippe
  , 2017, pp.CD_10_2. Summary form only given. Optical fibre (either classical or microstructured) is a favourable medium for realization of sources of entangled photons for quantum communications. Indeed the photon pairs are generated through spontaneous Four Wave Mixing (FWM) directly in the fibre core and can thus be connected easily and without loss to the optical telecommunication network.We have realized such a source and characterized its performance. Our measurements showed a photon pair generation rate lower than expected in theory. Further characterization showed, as can be seen in Fig. 1A, a widened pair spectrum and a diminution of the generation rate compared to the prediction of our model (Fig. 1B) [2]. Such features can be explained by taking in account the intrinsic inhomogeneity of the fibre, i.e. the core and cladding dimensions fluctuation along the fibre. Indeed, a small variation of the fibre diameter implies a slightly different dispersion, hence shifted photon pair frequencies. To depict these uniformities, we extended our model through a similar approach as in Ref. [3], considering the fibre as an assembly of homogeneous sections, each one with its own length and phase mismatch. Consequently, the joint spectral intensity of pairs describing their generation probability for a given couple of frequencies is more complex. In Fig. 1B, we show the result of our numerical simulation for a purely uniform fibre with parameters corresponding to our source [1,2], and in the case of a linear variation of the zero dispersion wavelength along the fibre. In this specific case, a new analytical solution that will be presented, can be derived from our model, and is also shown in Fig. 1B as a comparison. (10.1109/CLEOE-EQEC.2017.8086460)
  DOI : 10.1109/CLEOE-EQEC.2017.8086460
• Particle rejuvenation of Rao-Blackwellized Sequential Monte Carlo smoothers for Conditionally Linear and Gaussian models
  
  • Nguyen Ngoc Minh
  • Le Corff Sylvain
  • Moulines Éric
  EURASIP Journal on Advances in Signal Processing, SpringerOpen, 2017, 54. This paper focuses on Sequential Monte Carlo approximations of smoothing distributions in conditionally linear and Gaussian state spaces. To reduce Monte Carlo variance of smoothers, it is typical in these models to use Rao-Blackwellization: particle approximation is used to sample sequences of hidden regimes while the Gaussian states are explicitly integrated conditional on the sequence of regimes and observations, using variants of the Kalman filter / smoother. The first successful attempt to use Rao-Blackwellization for smoothing extends the Bryson-Frazier smoother for Gaussian linear state space models using the generalized two-filter formula together with Kalman filters / smoothers. More recently, a forward backward decomposition of smoothing distributions mimicking the Rauch-Tung-Striebel smoother for the regimes combined with backward Kalman updates has been introduced. This paper investigates the benefit of introducing additional rejuvenation steps in all these algorithms to sample at each time instant new regimes conditional on the forward and backward particles. This defines particle based approximations of the smoothing distributions whose support is not restricted to the set of particles sampled in the forward or backward filter. These procedures are applied to commodity markets which are described using a two factor model based on the spot price and a convenience yield for crude oil data. (10.1186/s13634-017-0489-5)
  DOI : 10.1186/s13634-017-0489-5
• Advanced contributions in HTTP adaptive streaming
  
  • Bouzakaria Nassima
  , 2017. HTTP adaptive streaming is a recent topic in multimedia communications with on-going standardization activities, especially with the MPEG-DASH standard which covers on demand and live services. One of the main issues in live services deployment is the reduction of various latencies, the initial delay before the playback and the overall end-to-end latency. In this thesis, we address the problem of these latencies in live DASH streaming. First, we review the causes of startup delay in DASH and common strategies used to reduce this delay. We propose a new method based on HTTP/1.1 and compatible with existing caching and delivery infrastructures for reducing the initial setup of an MPEG-DASH session. Second, we investigate the major contributor components to the end-to-end latency. We propose a complete novel low latency live DASH streaming system. Third, we show how such a low latency live DASH system can be used to enable combined broadcast and broadband services while keeping the client buffering requirements on the broadcast link low. Our proposed approach insures two functionalities: synchronization of both contents delivered through different distribution networks and keeping the client buffering requirements on the broadcast link low.