Publications

2017

• Méthode de séparation de sources appliquée aux données géoradar
  
  • Terrasse Guillaume
  • Nicolas Jean Marie
  • Trouvé Emmanuel
  , 2017.
• Convergence d'un algorithme du gradient proximal stochastique à pas constant et généralisation aux opérateurs monotones aléatoires
  
  • Salim Adil
  • Bianchi Pascal
  • Hachem Walid
  , 2017. – L'algorithme du gradient proximal permet de trouver les minimiseurs d'une somme F + G de deux fonctions convexes propres et fermées, l'une étant supposée dérivable. Cet article introduit une version stochastique de cet algorithme. Les itérations font intervenir une suite iid de deux fonctions aléatoires, dont les espérances coïncident respectivement avec F et G, ainsi que des projections aléatoires sur des ensembles convexes fermés. L'objectif est de fournir une analyse de convergence, dans un contexte adaptatif où le pas de l'algorithme est supposé constant. On montre que, en moyenne de Césaro, la probabilité pour que les itérées soient hors d'un voisinage des minimiseurs souhaités est arbitrairement faible lorsque le nombre d'itérations tend vers l'infini, et dans la limite de pas faibles. Le comportement ergodique des itérées est également étudié. Enfin, l'algorithme est étendu au contexte plus général des opérateurs maximaux monotones aléatoires. Abstract – The proximal gradient algorithm allows to find the minimizers of a sum F + G of two proper closed convex functions, one of them being differentiable. This paper introduces a stochastic version of the proximal gradient algorithm. The iterations involve an iid sequence of two random functions, whose expectations coincide with F and G respectively, as well as random projections onto closed convex sets. The aim is to provide a convergence analysis in an adaptive context where the step size of the algorithm is constant. We prove that, in Césaro mean, the probability that the iterates are away from the sought minimizers is small when the number of iterations tends to infinity and in the limit of small step sizes. The ergodic behavior is studied as well. Finally, the algorithm is extended to the context of random maximal monotone operators.
• LISP-Views: Monitoring LISP at Large Scale
  
  • Li Yue
  • Abouseif Akram
  • Iannone Luigi
  • Saucez Damien
  , 2017. The Locator/Identifier Separation Protocol (LISP) separates classical IP addresses into two categories: one for identifying terminals, the other for routing. To associate identifiers and locators LISP needs a specific mechanism, called mapping system. This technology is still at an early stage but two experimental platforms have already been deployed in the Internet: LISP Beta Network and LISP-Lab. However, only the LISP Beta Network is monitored with LISPmon that partially monitors the mapping system once a day. To accompany the growth of LISP, a dynamic and complete monitoring system is required. Therefore, we propose LISP-Views, a dynamic versatile large scale LISP monitoring architecture. LISP-Views allows to automatically conduct comprehensive and objective measurements. After running LISP-Views in the wild for several months and comparing the monitoring results with LISPmon, we confirm that LISP-Views provides more detailed and accurate information. We observe the different behaviours between every network entity within mapping system, and also explore the current LISP performance for further improvements.
• A Semi-Automated Approach for the Co-Refinement of Requirements and Architecture Models
  
  • Barkowski Matthias
  • Schneider Melanie
  • Giese Holger
  • Dyck Johannes
  • Tamzalit Dalila
  • Blouin Dominique
  • Borde Etienne
  • Noppen Joost
  , 2017. Requirements and architecture specifications are strongly related as the second provides a solution to a problem stated by the first. This coupling is typically realized by traceability links and maintaining such links becomes extremely difficult as both requirements and architecture specifications frequently evolve, and in particular when the architecture is refined providing an increasing level of details. In such case, not only the traceability must evolve but the requirements must be refined as well. We present a novel semi-automated approach to evolve non-functional requirements and their traceability links following system's architecture refinement in the context of design space exploration and automated code generation. The approach has been prototyped for AADL models refined with the RAMSES tool and for model transformations implemented as Story Diagrams. (10.1109/REW.2017.52)
  DOI : 10.1109/REW.2017.52
• Characterization of the 3F4-3H6 transition in thulium-doped silica fibres and simulation of a 2µm single clad amplfier
  
  • Romano Clément
  • Tench Robert E.
  • Delavaux Jean-Marc
  • Jaouën Yves
  , 2017, pp.paper P1.SC1.1.
• 2017
  
  • Eagan James R
  , 2017.
• A Hybrid Methodology for the Performance Evaluation of Internet-scale Cache Networks
  
  • Leonardi E.
  • Rossi Dario
  • Tortelli Michele
  Elsevier Computer Networks, 2017, 125, pp.146-159. Two concurrent factors challenge the evaluation of large-scale cache networks: complex algorithmic interactions, which are hardly represented by analytical models, and catalog/network size, which limits the scalability of event-driven simulations. To solve these limitations, we propose a new hybrid technique, that we colloquially refer to as ModelGraft, which combines elements of stochastic analysis within a simulative Monte-Carlo approach. In ModelGraft, large scenarios are mapped to a downscaled counterpart built upon Time-To-Live (TTL) caches, to achieve CPU and memory scalability. Additionally, a feedback loop ensures convergence to a consistent state, whose performance accurately represent those of the original system. Finally, the technique also retains simulation simplicity and flexibility, as it can be seamlessly applied to numerous forwarding, meta-caching, and replacement algorithms. We implement and make ModelGraft available as an alternative simulation engine of ccnSim. Performance evaluation shows that, with respect to classic event-driven simulation, ModelGraft gains over two orders of magnitude in both CPU time and memory complexity, while limiting accuracy loss below 2%. Ultimately, ModelGraft pushes the boundaries of the performance evaluation well beyond the limits achieved in the current state of the art, enabling the study of Internet-scale scenarios with content catalogs comprising hundreds billions objects.
• Parameter sensitivity analysis of the Energy/Frequency Convexity Rule for application processors
  
  • de Vogeleer Karel
  • Memmi Gérard
  • Jouvelot Pierre
  Journal of Sustainable Computing, Informatics and Systems, 2017, 15, pp.16-27.
• Analysis of Ageing effects on ARTIX7 XILINX FPGA
  
  • Slimani Mariem
  • Benkalaia Karim
  • Naviner Lirida
  , 2017.
• Experimental demonstration of space-time coding for MDL mitigation in few-mode fiber transmission system
  
  • Amhoud El Mehdi
  • Rekaya-Ben Othman Ghaya
  • Bigot Laurent
  • Song Mengdi
  • Andresen Esben-Ravn
  • Labroille Guillaume
  • Bigot-Astruc Marianne
  • Jaouën Yves
  , 2017, paper M.1.D.2.
• Machine-Learning Meets Extreme Value Theory
  
  • Clémençon Stéphan
  , 2017.
• Towards combining admission control and link scheduling in wireless mesh networks
  
  • Dromard Juliette
  • Khoukhi Lyes
  • Khatoun Rida
  • Begriche Youcef
  Telecommunication Systems, Springer Verlag (Germany), 2017, 66 (1), pp.39-54. Wireless mesh networks (WMNs) have emerged recently as a key solution for next-generation wireless networks; they are low cost and easily deployed technology. However, WMNs have to deal with a low bandwidth which prevents them from guaranteeing the requirements of applications with strict constraints. To overcome this limitation, we propose in this paper a new admission control model which integrates a dynamic link scheduling scheme, named ACLS, in order to optimize the network bandwidth use. We formulate the admission control problem as a binary linear programming problem (BL2P). The proposed admission control integrates an algorithm, based on the Dakin’s branch and bound (B&B) method, which respects the bandwidth and delay required by the flows. The proposed ACLS solution has been validated on ns2, and the simulation results showed that ACLS model has better performance than the reference solution BRAWN; it accepts more flows while guaranteeing their delay and bandwidth. (10.1007/s11235-016-0273-0)
  DOI : 10.1007/s11235-016-0273-0
• An Interactive E-book with an Educational Game for Children with Developmental Disorders: A Pilot User Study
  
  • Pistoljevic Nirvana
  • Hulusic Vedad
  , 2017. Children diagnosed with Autism spectrum disorder (ASD), as one of the most complex neurodevelopmental disabilities, are characterized by different brain and functioning development, distinct interaction with the environment and different learning patterns, language and social skills impairments, and repetitive auto-stimulating restricting behaviors. It has been shown that computer-assisted intervention is much more attention captivating and interesting to children compared with a classic approach to teaching, allowing for faster acquisition of skills. This makes these tools and the technology highly suitable for teaching children with autism basic developmental skills. In addition, interactive electronic books showed positive outcomes for comprehension and information acquisition in children with ASD, while decreasing inappropriate children behavior in the classroom. In this paper a pilot user study on an e-book with an embedded educational game for children with developmental disorders was presented. The results show that the e-book can be efficiently used for teaching children with ASD basic developmental skills and that the learned skills can be efficiently transfered to new media and environments. The framework will provide preschool children with and without disabilities with appropriate educational software, to build up their early cognitive abilities and school readiness skills, and promote incorporating technology as part of the educational and pedagogical process in schools.
• Comparison of the nonlinear frequency division multiplexing and OFDM in experiment
  
  • Gemechu Wasyhun A.
  • Song Mengdi
  • Jaouën Yves
  • Wabnitz Stephano
  • Yousefi Mansoor
  , 2017, pp.paper W.3.C.4.
• Rethinking of I/O-Automata Composition
  
  • Chabane Sarah
  • Ameur-Boulifa Rabéa
  • Mezghiche Mohamed
  , 2017.
• Adapting to unknown noise level in sparse deconvolution
  
  • Boyer Claire
  • de Castro Yohann
  • Salmon Joseph
  Information and Inference, Oxford University Press (OUP), 2017. In this paper, we study sparse spike deconvolution over the space of complex-valued measures when the input measure is a finite sum of Dirac masses. We introduce a modified version of the Beurling Lasso (BLasso), a semi-definite program that we refer to as the Concomitant Beurling Lasso (CBLasso). This new procedure estimates the target measure and the unknown noise level simultaneously. Contrary to previous estimators in the literature, theory holds for a tuning parameter that depends only on the sample size, so that it can be used for unknown noise level problems. Consistent noise level estimation is standardly proved. As for Radon measure estimation, theoretical guarantees match the previous state-of-the-art results in Super-Resolution regarding minimax prediction and localization. The proofs are based on a bound on the noise level given by a new tail estimate of the supremum of a stationary non-Gaussian process through the Rice method. (10.1093/imaiai/iaw024)
  DOI : 10.1093/imaiai/iaw024
• Unsharp Masking Geometry Improves 3D Prints
  
  • Herholz Philipp
  • Koch Sebastian
  • Boubekeur Tamy
  • Alexa Marc
  Computer & Graphics (Proc. Shape Modeling International 2017), 2017, 66, pp.135-142. Mass market digital manufacturing devices are severely limited in accuracy and material, resulting in a significant gap between the appearance of the virtual and the real shape. In imaging as well as rendering of shapes, it is common to enhance features so that they are more apparent. We provide an approach for feature enhancement that directly operates on the geometry of a given shape, with particular focus on improving the visual appearance for 3D printing. The technique is based on unsharp masking, modified to handle arbitrary free-form geometry in a stable, efficient way, without causing large scale deformation. On a series of manufactured shapes we show how features are lost as size of the object decreases, and how our technique can compensate for this. We evaluate this effect in a human subject experiment and find significant preference for modified geometry.
• MuLoG, or How to apply Gaussian denoisers to multi-channel SAR speckle reduction?
  
  • Deledalle Charles-Alban
  • Denis Loïc
  • Tabti Sonia
  • Tupin Florence
  IEEE Transactions on Image Processing, Institute of Electrical and Electronics Engineers, 2017, 26 (9), pp.4389-4403. Speckle reduction is a longstanding topic in synthetic aperture radar (SAR) imaging. Since most current and planned SAR imaging satellites operate in polarimetric, interferometric or tomographic modes, SAR images are multi-channel and speckle reduction techniques must jointly process all channels to recover polarimetric and interferometric information. The distinctive nature of SAR signal (complex-valued, corrupted by multiplicative fluctuations) calls for the development of specialized methods for speckle reduction. Image denoising is a very active topic in image processing with a wide variety of approaches and many denoising algorithms available, almost always designed for additive Gaussian noise suppression. This paper proposes a general scheme, called MuLoG (MUlti-channel LOgarithm with Gaussian denoising), to include such Gaussian denoisers within a multi-channel SAR speckle reduction technique. A new family of speckle reduction algorithms can thus be obtained, benefiting from the ongoing progress in Gaussian denoising, and offering several speckle reduction results often displaying method-specific artifacts that can be dismissed by comparison between results. (10.1109/TIP.2017.2713946)
  DOI : 10.1109/TIP.2017.2713946
• Minimisation de la puissance émise dans les réseaux ad hoc utilisant l'ARQ hybride de Type-I sur canal de Rice
  
  • Leturc Xavier
  • Le Martret C.
  • Ciblat Philippe
  , 2017.
• Procede de simplification de modele de geometrie
  
  • Legrand Hélène
  • Boubekeur Tamy
  , 2017.
• Identification of a thermal building model by learning the dynamics of the solar flux
  
  • Nabil Tahar
  • Roueff François
  • Jicquel Jean-Marc
  • Girard Alexandre
  , 2017.
• Impact of CPU load on video conferencing quality
  
  • Sorokin Roman
  • Rougier Jean-Louis
  • Ricardo Pastrana-Vidal
  • Nicolas Tranquart
  , 2017, 2017. Video conferencing is a well-established area of communications, which have been studied for decades. Recently this area has received a new impulse due to significantly increased bandwidth of Local and Wide area networks and appearance of low-priced video equipment. At the same time, high quality video images such as Full HD may require significant computational resources for their processing. Video processing for conferencing encompasses all manipulations necessary to get advanced user experience (mixing together several video streams or switch the image to the currently speaking participant) as well as operations caused by the incompatibility of endpoints, e.g. trans-coding in the case when participants use different video codecs. (10.1109/IPTCOMM.2017.8169753)
  DOI : 10.1109/IPTCOMM.2017.8169753
• CAM-Infrastructure: a novel solution for service advertise- ment in Cooperative Intelligent Transportation Systems
  
  • Hammi Badis
  • Labiod Houda
  • Segarra Gérard
  • Servel Alain
  • Monteuuis Jean-Philippe
  Advances in Science, Technology and Engineering Systems Journal, Advances in Science Technology and Engineering Systems Journal (ASTESJ), 2017, 2 (3), pp.1422-1431. Cooperative Intelligent Transportation Systems (C-ITS) are gaining ground and currently are almost part of our everyday life. A C-ITS environment can provide numerous services that soon will become essential to roads’ users. The latter resides in improvement of road safety, entertainment, and commercial services. However, in order to provide such services, the C-ITS environment needs an advertisement and dissemination service for them. Indeed, users have to be aware of the available services in order to request them if needed. Current standards of service announcement show their limits, especially regarding the interoperability between communication profiles. For this reason, in this paper, we describes our new service advertisement solution called CAM-Infrastructure. The latter is compliant with ETSI standards and is deployed in SCOOP@F, a nationwide scale project. (10.25046/aj0203178)
  DOI : 10.25046/aj0203178
• Sur l'extremum d'entropie pour les transformations linéaires
  
  • Rioul Olivier
  , 2017. Comme pour le fameux principe de maximum d’entropie, le principe de minimum d’entropie permet de mesurer le caractère gaussien d’un signal. On présente une nouvelle démonstration très simple de ce principe appliqué aux transformations linéaires, qui s’exprime par une inégalité de puissance entropique initialement due à Shannon et généralisée par Zamir et Feder. Cette démonstration est basée sur un argument de transport optimal qui prend la forme d’un simple changement de variables et permet d’établir facilement la condition d’égalité.
• Exploiting Parallelism in Hierarchical Content Stores for High-speed ICN Routers
  
  • Mansilha Rodrigo
  • Barcellos Marinho
  • Leonardi E.
  • Rossi Dario
  Elsevier Computer Networks, 2017, 125, pp.132-145. Information-centric network (ICN) is a novel architecture identifying data as a first class citizen, and caching as a prominent low-level feature. Yet, efficiently using large storage (e.g., 1 TB) at line rate (e.g., 10 Gbps) is not trivial: in our previous work, we proposed an ICN router design equipped with hierarchical caches, that exploits peculiarities of the ICN traffic arrival process. In this paper, we implement such proposal in the NDN Forwarding Daemon (NFD), and carry on a thorough experimental evaluation of its performance with an emulation methodology on common off the shelf hardware. Our study testifies the interest and feasibility of the approach.