Publications

2019

• A 3D Beamforming Scheme Based on The Spatial Distribution of User Locations
  
  • Rachad Jalal
  • Nasri Ridha
  • Decreusefond Laurent
  , 2019. Multi-antenna technologies such as massive Multiple-Input Multiple-Output (massive MIMO) and beamforming are key features to enhance performance, in terms of capacity and coverage, by using a large number of antennas intelligently. With the upcoming 5G New Radio (NR), FD-MIMO (Full Dimension MIMO) will play a major key role. FD-MIMO consists in arranging a large number of antennas in a 2D array, which enables to use 3D beamforming i.e., beamforming in both horizontal and vertical dimensions. The present paper provides a 3D beamforming model where beam steering depends on the random spatial distribution of users. We attempt to derive some analytical results regarding the probability distribution of antenna beamforming radiation pattern. Also, through system level simulations, we show how 3D beamforming can reduce interference impact, compared to the traditional 2D beamforming, and enhances system performance in terms of the coverage probability and users throughput.
• On-the-fly Detection of User Engagement Decrease in Spontaneous Human-Robot Interaction
  
  • Ben Youssef Atef
  • Varni Giovanna
  • Essid Slim
  • Clavel Chloé
  International Journal of Social Robotics, 2019. In this paper, we address the detection of engagement decrease of users spontaneously interacting with a socially assistive robot in a public space. We first describe the UE-HRI dataset that collects spontaneous Human-Robot Interactions following the guidelines provided by the Affective Computing research community to collect data "in-the-wild". We then analyze the users' behaviors focusing on proxemics, gaze, head motion, facial expressions and speech during interactions with the robot. Engaged behaviors versus signs of engagement decrease exhibited by the users were annotated and analyzed. Finally, we investigate the use of deep leaning techniques (Recurrent and Deep Neural Networks) to detect user engagement decrease in real-time. The results of this work particularly highlight the relevance of taking into account temporal dynamics of the user's behavior. Allowing 1 to 2 seconds as buffer delay improves the performance of taking a decision on user engagement.
• Merit-guided dynamic feature selection filter for data streams
  
  • Barddal Jean Paul
  • Enembreck Fabrício
  • Gomes Heitor Murilo
  • Bifet Albert
  • Pfahringer Bernhard
  Expert Syst. Appl., 2019, 116, pp.227-242. (10.1016/j.eswa.2018.09.031)
  DOI : 10.1016/j.eswa.2018.09.031
• QFib: Fast and Accurate Compression of White Matter Tractograms
  
  • Rousseau Sylvain
  • Mercier Corentin
  • Gori Pietro
  • Bloch Isabelle
  • Boubekeur Tamy
  , 2019.
• A Conditional Gradient-Based Augmented Lagrangian Framework
  
  • Yurtsever Alp
  • Fercoq Olivier
  • Cevher Volkan
  , 2019, 97. This paper considers a generic convex minimization template with affine constraints over a compact domain, which covers key semidefinite programming applications. The existing conditional gradient methods either do not apply to our template or are too slow in practice. To this end, we propose a new conditional gradient method, based on a unified treatment of smoothing and augmented Lagrangian frameworks. The proposed method maintains favorable properties of the classical conditional gradient method, such as cheap linear minimization oracle calls and sparse representation of the decision variable. We prove $\mathcal{O}(1/\sqrt{k})$ convergence rate of our method in the objective residual and the feasibility gap. This rate is essentially the same as the state of the art CG-type methods for our problem template, but the proposed method is significantly superior to existing methods in various semidefinite programming applications.
• Medical imaging and AI
  
  • Bloch Isabelle
  , 2019.
• The $f$-divergence expectation iteration scheme
  
  • Daudel Kamélia
  • Douc Randal
  • Portier François
  • Roueff François
  , 2019. This paper introduces the $f$-EI$(\phi)$ algorithm, a novel iterative algorithm which operates on measures and performs $f$-divergence minimisation in a Bayesian framework. We prove that for a rich family of values of $(f,\phi)$ this algorithm leads at each step to a systematic decrease in the $f$-divergence and show that we achieve an optimum. In the particular case where we consider a weighted sum of Dirac measures and the $\alpha$-divergence, we obtain that the calculations involved in the $f$-EI$(\phi)$ algorithm simplify to gradient-based computations. Empirical results support the claim that the $f$-EI$(\phi)$ algorithm serves as a powerful tool to assist Variational methods.
• Deep learning approaches for electrical vehicular mobility management
  
  • Dridi Aicha
  • Boucetta Chérifa
  • Alhassan Abubakar Yau
  • Moungla Hassine
  • Afifi Hossam
  • Labiod Houda
  , 2019, pp.1-6. Electrical vehicular (EV) energy management is a promising trend. Forecasting vehicular trajectories and delay is crucial for EV energy management. The presented work is devoted to the study and the application of deep learning techniques on specific road trajectories. First, exhaustive deep learning algorithms are considered. Second, road traces are converted to time series. Then, delays and road trajectories are analyzed. In fact, we consider two Recurrent Neural Networks (RNN): LSTM (Long Short Term Memory) and GRU (Gated Recurrent Units). Neural Networks are adapted and trained on 60 days of real urban traffic of Rome in Italy. We calculate the Loss function for both machine learning techniques which is defined by mean square error (MSE) and Root mean square error (RMSE). Experimental results demonstrate that both LSTM and GRU are adequate for the context of EV in terms of route trajectory and delay prediction. (10.1109/WINCOM47513.2019.8942569)
  DOI : 10.1109/WINCOM47513.2019.8942569
• Three-Weight Minimal Linear Codes and Their Applications
  
  • Mesnager Sihem
  • Sinak A.
  • Yayla O.
  , 2019.
• Linear codes from weakly regular plateaued functions and their secret sharing schemes.
  
  • Mesnager Sihem
  • Özbudak Ferruh
  • Sinak A.
  Designs, Codes and Cryptography, Springer Verlag, 2019.
• Depth and Depth-Based Classification with R Package ddalpha
  
  • Pokotylo Oleksii
  • Mozharovskyi Pavlo
  • Dyckerhoff Rainer
  Journal of Statistical Software, University of California, Los Angeles, 2019, 91 (5). (10.18637/jss.v091.i05)
  DOI : 10.18637/jss.v091.i05
• Study of short and mid-infrared telecom links performance for different climatic conditions
  
  • Sauvage Chloé
  • Robert Clélia
  • Sorrente Béatrice
  • Grillot Frédéric
  • Erasme Didier
  , 2019, pp.18. This study assesses the performance in term of availability of a FSO (Free Space Optics) link for two wavelengths, belonging to atmospheric windows, the standard telecom wavelength 1.55 µm and the mid-infrared wavelength 4 µm. To do so, we compute the transmission rate under various atmospheric conditions, including fog. Using the atmospheric transmission rate from our radiative transfer software MATISSE, the link budget is derived for a simple direct emission and detection system. The source and detector components characteristics, from commercial data-sheet, are considered to compute the reception noise. An estimate of the Bit Error Rate (BER) of the FSO link for the two wavelengths is presented as a function of visibility. Assuming a bit error correction and the corresponding BER value, it is possible to derive the limit of visibility under which the optical link is cut. A weather visibility database has been collected and compiled for a year to obtain the theoretical availability of the FSO system. As an example the availability at Velizy-Villacoublay (France) weather station throughout the year 2017 is used. In this case the theoretical link availability wins 30 hours of operation in January 2017 with the 4 µm optical wavelength, that shows the benefit of using mid-infrared for FSO when fog occurs. (10.1117/12.2533209)
  DOI : 10.1117/12.2533209
• Computing Possible and Certain Answers over Order-Incomplete Data
  
  • Amarilli Antoine
  • Ba Mouhamadou Lamine
  • Deutch Daniel
  • Senellart Pierre
  Theoretical Computer Science, Elsevier, 2019, 797, pp.42-76. This paper studies the complexity of query evaluation for databases whose relations are partially ordered; the problem commonly arises when combining or transforming ordered data from multiple sources. We focus on queries in a useful fragment of SQL, namely positive relational algebra with aggregates, whose bag semantics we extend to the partially ordered setting. Our semantics leads to the study of two main computational problems: the possibility and certainty of query answers. We show that these problems are respectively NP-complete and coNP-complete, but identify tractable cases depending on the query operators or input partial orders. We further introduce a duplicate elimination operator and study its effect on the complexity results. (10.1016/j.tcs.2019.05.013)
  DOI : 10.1016/j.tcs.2019.05.013
• Following and Analyzing a Human Being: On the Continuity and Singularity of an Individual
  
  • Kneubühler Marine
  • Piette Albert
  , 2019, pp.13-43. This chapter addresses three restrictions observed within the social sciences that prevent researchers from seeing human beings as such. It proposes an ontological argument in favor of following and analyzing human individuals. The chapter compares phenomenography with some phenomenological approaches in anthropology in order to insist on the methodological radicality of the former. As reflected in philosophy's classic debates, an anthropology that sets out to be anthropo-focused cannot separate an action, connection or experience from the person who performs and lives it. The chapter provides the methodological guidelines concerning, in particular, the possible ways of beginning a phenomenographic research which focuses on the rapper LK. It focuses on what calls a "videophenomenography", which corresponds to the moment where LK agreed to film himself, alone, during the creation of a verse. One particularly interesting device attempted was the realization of a "videophenomenography", in which LK agreed to film himself, alone, during a moment of creation.
• Knowledge Representation and Model-based Image Understanding
  
  • Bloch Isabelle
  , 2019.
• Nervous System Exploration Using Tractography To Enhance Pelvic Surgery
  
  • Muller Cécile
  • Delmonte Alessandro
  • Meignan Pierre
  • Peyrot Quoc
  • Virzi Alessio
  • Berteloot Laureline
  • Grevent David
  • Blanc Thomas
  • Gori Pietro
  • Boddaert Nathalie
  • Bloch Isabelle
  • Sarnacki Sabine
  , 2019. Pelvic surgery raises the challenge of preser- vation of nerves that handle urinary, gen- ital and digestive functions, especially in situations where these structures may be modi- fied by tumors or malformations. Recent works on 3D nerve visualization, that rely on cadavers dissections [1, 3] or intra-operative use of probes detecting myelin-binding fluorophores [5], do not provide pre- or post-operative analysis of the pelvic nervous anatomy. Magnetic reso- nance neurography as in [12] requires a slice by slice manual segmentation of the nerves. Dif- fusion MRI, associated with tractography algo- rithms, is currently the only technique allow- ing for in-vivo exploration of the nervous net- work [2] with no need for manual nerve segmen- tation. In contrast to brain imaging that moti- vated a lot of work, only few studies focus on pe- ripheral nerves visualization [9, 10, 14]. In this paper, we propose a method for pelvic tractog- raphy analysis based on patient-specific organ segmentation. It is demonstrated with promis- ing results on a healthy adult subject.
• Segmentation of retinal arterial bifurcations in 2D adaptive optics ophtalmoscopy images
  
  • Trimeche Iyed
  • Rossant Florence
  • Bloch Isabelle
  • Pâques M.
  , 2019, pp.1490-1494. The study of vascular morphometry requires segmenting vessels with high precision. Of particular clinical interest is the morphometric analysis of arterial bifurcations in Adaptive Optics Ophthalmoscopy (AOO) images of eye fundus. In this paper, we extend our previous approach for segmenting retinal vessel branches to the segmentation of bifurcations. This enables us to recover the microvascular tree and extract biomarkers that charactarize the blood flow. Segmentation results are shown to be within the range of intra- and inter-user variability, allowing a preliminary study on biomarkers derived from vessel diameter estimates at arterial bifurcations.
• Mathematical Morphology and Musical Representations
  
  • Agon Carlos
  • Andreatta Moreno
  • Atif Jamal
  • Bloch Isabelle
  , 2019.
• Audiovisual Analysis of Music Performances: Overview of an Emerging Field
  
  • Duan Zhiyao
  • Essid Slim
  • Liem Cynthia
  • Richard Gael
  • Sharma Gaurav
  IEEE Signal Processing Magazine, Institute of Electrical and Electronics Engineers, 2019, 36 (1), pp.63-73.
• Comprehensive review of 3D segmentation software tools for MRI usable for pelvic surgery planning
  
  • Virzi Alessio
  • Muller Cécile
  • Marret Jean-Baptiste
  • Mille Eva
  • Berteloot Laureline
  • Grevent David
  • Boddaert Nathalie
  • Gori Pietro
  • Sarnacki Sabine
  • Bloch Isabelle
  Journal of Digital Imaging, 2019. Background: Patient specific 3D modeling is the first step towards image-guided surgery, the actual revolution in surgical care. Pediatric and adolescent patients with rare tumors and malformations should highly benefit from these latest technological innovations, allowing personalized tailored surgery. This study focused on the pelvic region, located at the crossroads of the urinary, digestive and genital channels with important vascular and nervous structures. The aim of this study was to evaluate the performances of different software tools to obtain patient specific 3D models, through segmentation of magnetic resonance images (MRI), the reference for pediatric pelvis examination. Methods: Twelve software tools freely available on the Internet and two commercial software tools were evaluated using T2-w MRI and diffusion- weighted MRI images. The software tools were rated accordingly to eight criteria, evaluated by three different users: automatization degree, segmentation time, usability, 3D visualization, presence of image registration tools, tractography tools, supported OS, and potential extension (i.e. plugins). Results: A ranking of software tools for 3D modeling of MRI medical images, according to the set of predefined criteria, was given. This ranking allowed us to elaborate guidelines for the choice of software tools for pelvic surgical planning in pediatric patients. The best-ranked software tools were Myrian Studio, ITK-SNAP and 3D Slicer, the latter being especially appropriate if nerve fibers should be included in the 3D patient model. Conclusion: This study proposed a comprehensive review of software tools for 3D modeling of the pelvis according to a set of eight criteria, and delivered specific conclusions for pediatric and adolescent patients that can be directly applied to clinical practice.
• Tournez méninges
  
  • Zayana Karim
  Au fil des maths, APMEP, 2019. Du repérage sur le cercle à la mesure de l'épaisseur d'une ruban d'adhésif
• Constructions of optimal locally recoverable codes via Dickson polynomials
  
  • Mesnager Sihem
  • Liu J.
  • Tang D.
  , 2019.
• Kindey Cortex Segmentation in 2D CT with U-Nets Ensemble Aggregation
  
  • Couteaux Vincent
  • Si-Mohamed S.
  • Renard-Penna R.
  • Nempont O.
  • Lefevre T.
  • Popoff A.
  • Pizaine Guillaume
  • Villain N.
  • Bloch Isabelle
  • Behr J.
  • Bellin M.-F.
  • Roy C.
  • Rouvière O.
  • Montagne S.
  • Lassau N.
  • Boussel L.
  Diagnostic and Interventional Imaging, Elsevier, 2019, 100, pp.211-217.
• Etude du développement du système nerveux périphérique pelvien : du foetus à l'enfant porteur de malformations et tumeurs pelviennes
  
  • Meignan P.
  • Muller C.
  • Belle M.
  • Peyrot Q.
  • Delmonte A.
  • Berteloot L.
  • Grevent D.
  • Blanc T.
  • Boddaert N.
  • Chedotal A.
  • Bloch Isabelle
  • Sarnacki S.
  , 2019.
• Systematic Literature Review on Multi-Paradigm Modelling for Cyber-Physical Systems
  
  • Barisic Ankica
  • Savić Dušan
  • Al-Ali Rima
  • Ruchkin Ivan
  • Blouin Dominique
  • Cicchetti Antonio
  • Eslampanah Raheleh
  • Nikiforova Oksana
  • Abshir Mustafa
  • Challenger Moharram
  • Gomes Claudio
  • Erata Ferhat
  • Tekinerdogan Bedir
  • Amaral Vasco
  • Goulao Miguel
  , 2019.