Publications

2019

• Fault Analysis Assisted by Simulation
  
  • Chibani Kais
  • Facon Adrien
  • Guilley Sylvain
  • Marion Damien
  • Mathieu Yves
  • Sauvage Laurent
  • Souissi Youssef
  • Takarabt Sofiane
  , 2019, pp.263-277. Side-channel and fault injection attacks are renown techniques to extract keys from cryptographic devices. Fortunately, leakage reduction and fault detection countermeasures exist and can be implemented right in the source-code. However, source-code level countermeasures might be altered during the compilation process. Design simulation is an effective means to detect such harmful simplifications. This is a well-known methodology to analyze regressions in terms of side-channel leakage. In this chapter, we explain that protections against fault injection attacks are no exception. First of all, we show that vulnerabilities to those attacks can be easily detected by simulation methods. Second, we highlight that simulation techniques are also highly efficient in detecting logic simplifications which destroy (fully or partly) the countermeasures. Thus, the simulation-based methodology we present in this chapter shows that it is possible to decide quickly which compilation options are safe and which ones are detrimental to the security. (10.1007/978-3-030-11333-9_12)
  DOI : 10.1007/978-3-030-11333-9_12
• Learning-based tone mapping operator for efficient image matching
  
  • Rana Aakanksha A
  • Valenzise Giuseppe
  • Dufaux Frédéric
  IEEE Transactions on Multimedia, Institute of Electrical and Electronics Engineers, 2019, 21 (1), pp.256-268. In this paper, we propose a new framework to optimally tone map the high dynamic range (HDR) content for image matching under drastic illumination variations. Since tone mapping operators (TMO) have traditionally been used for displaying HDR scenes, their design is suboptimal when used for computer vision tasks such as image matching. We address this sub-optimality by proposing a two-step framework, consisting of: a) a luminance-invariant guidance model based on a Support Vector Regressor (SVR) to optimally adapt the tone mapping function for image matching; and b) an energy maximization model to generate appropriate training samples for learning the SVR. At each step, we collectively address both stages of keypoint detection and descriptor extraction in the feature matching framework. By locally altering the intrinsic characteristics of the tone mapping function, the learned guid- ance model facilitates the extraction of local invariant features in the presence of illumination variations. We demonstrate that the proposed TMO significantly outperforms perceptually-driven state-of-the-art TMOs on a dataset of HDR scenes characterized by challenging lighting variations, such as day/night transitions. (10.1109/TMM.2018.2839885)
  DOI : 10.1109/TMM.2018.2839885
• A statistical detection mechanism for node misbehaviours in wireless mesh networks
  
  • Khatoun Rida
  • Begriche Youcef
  • Khoukhi Lyes
  IJAHUC - International Journal of Ad Hoc and Ubiquitous Computing, Inderscience, 2019, 31 (1), pp.23. (10.1504/IJAHUC.2019.099637)
  DOI : 10.1504/IJAHUC.2019.099637
• Compressed sensing-enabled phase-sensitive swept-source optical coherence tomography
  
  • Ling Yuye
  • Meiniel William
  • Singh-Moon Rajinder
  • Angelini Elsa D.
  • Olivo-Marin J.-C.
  • Hendon Christine P.
  Optics Express, Optical Society of America - OSA Publishing, 2019, 27 (2), pp.855-871.
• Segmentation et caractérisation des bifurcations artérielles rétiniennes dans des images 2D d’optique adaptative
  
  • Trimeche Iyed
  • Rossant Florence
  • Bloch Isabelle
  • Pâques M.
  , 2019. Nous pr ́esentons une m ́ethode de segmentation des art`eres r ́etiniennes dans des images de fond d’oeil de haute r ́esolution, acquises en optique adaptative. Nous e ́ tendons notre approche pr ́ec ́edente de traitement des branches des vaisseaux r ́etiniens a ` la segmentation des bifur- cations, ce qui nous permet d’analyser l’int ́egralit ́e de l’arbre vasculaire. Diff ́erents biomarqueurs caract ́erisant le flux sanguin sont extraits de l’estimation des diam`etres des branches aux bifurcations. Les r ́esultats exp ́erimentaux montrent que la pr ́ecision de notre approche se situe dans la plage de variabilit ́e intra- et inter-utilisateurs, ce qui nous a permis de r ́ealiser une e ́ tude pr ́eliminaire sur les biomarqueurs extraits.
• Safe Grid Search with Optimal Complexity
  
  • Ndiaye Eugene
  • Le Tam
  • Fercoq Olivier
  • Salmon Joseph
  • Takeuchi Ichiro
  , 2019, 97, pp.4771-4780. Popular machine learning estimators involve regularization parameters that can be challenging to tune, and standard strategies rely on grid search for this task. In this paper, we revisit the techniques of approximating the regularization path up to predefined tolerance $\epsilon$ in a unified framework and show that its complexity is $O(1/\sqrt[d]{\epsilon})$ for uniformly convex loss of order $d>0$ and $O(1/\sqrt{\epsilon})$ for Generalized Self-Concordant functions. This framework encompasses least-squares but also logistic regression (a case that as far as we know was not handled as precisely by previous works). We leverage our technique to provide refined bounds on the validation error as well as a practical algorithm for hyperparameter tuning. The later has global convergence guarantee when targeting a prescribed accuracy on the validation set. Last but not least, our approach helps relieving the practitioner from the (often neglected) task of selecting a stopping criterion when optimizing over the training set: our method automatically calibrates it based on the targeted accuracy on the validation set.
• Frequency comb dynamics of a 13 μm hybrid-silicon quantum dot semiconductor laser with optical injection
  
  • Beausoleil Raymond G
  • Grillot Frédéric
  • Dong Bozhang
  • Huang Heming
  • Duan Jianan
  • Kurczveil Geza
  • Liang Di I
  Optics Letters, Optical Society of America - OSA Publishing, 2019, 44 (23), pp.5755. This work reports on the influence of bias voltage applied on a saturable absorber (SA) on a subthreshold linewidth enhancement factor (LEF) in hybrid-silicon quantum dot optical frequency comb lasers. Results show that the reverse bias voltage on SA contributes to enlarge the LEF and improve the comb dynamics. Optical injection is also found to be able to improve the comb spectrum in terms of 3 dB bandwidth and its flatness. Such novel findings are promising for the development of high-speed dense wavelength-division multiplexing photonic integrated circuits in optical interconnects and datacom applications. (10.1364/OL.44.005755)
  DOI : 10.1364/OL.44.005755
• •Intelligent Systems for Crisis Management: Gi4DM 2018
  
  • Altan Orhan
  • Chandra Madhu
  • Sunar F
  • Tanzi Tullio
  Lecture Notes in Geoinformation and Cartography, Springer International Publishing, 2019. In the past several years, there have been significant technological advances in the field of crisis response. However, many aspects concerning the efficient collection and integration of geo-information, applied semantics and situation awareness for disaster management remain open. Improving crisis response systems and making them intelligent requires extensive collaboration between emergency responders, disaster managers, system designers and researchers alike. To facilitate this process, the Gi4DM (GeoInformation for Disaster Management) conferences have been held regularly since 2005. The events are coordinated by the Joint Board of Geospatial Information Societies (JB GIS) and ICSU GeoUnions. This book presents the outcomes of the Gi4DM 2018 conference, which was organised by the ISPRS-URSI Joint Working Group ICWG III/IVa: Disaster Assessment, Monitoring and Management and held in Istanbul, Turkey on 18-21 March 2018. It includes 12 scientific papers focusing on the intelligent use of geo-information, semantics and situation awareness. (10.1007/978-3-030-05330-72019)
  DOI : 10.1007/978-3-030-05330-72019
• Analysis of CEDBT and CESM performance using a realistic X-ray simulation platform
  
  • Sanchez de La Rosa Ruben
  • Carton A.-K.
  • Milioni de Carvalho P.
  • Bloch Isabelle
  • Muller S.
  , 2019, pp.1070-1073. Contrast Enhanced Spectral Mammography (CESM) and Contrast Enhanced Digital Breast Tomosynthesis (CEDBT) are multi-energy X-ray imaging techniques involving the injection of a vascular contrast agent. Both techniques provide information on hypervascularization of lesions through contrast uptake. CESM has proved to deliver a better diagnosis of breast cancer than diagnostic mammography. CEDBT is a promising technique which provides 3D information on the contrast uptake distribution. In this paper, new steps in the image acquisition process of a previously presented image acquisition simulation platform are described, including models of scatter, image lag and electronic noise. Using this simulation platform, 290 CESM and CEDBT images were generated. A human observer experiment was then performed to compare lesion detectability and characterization. The results indicate a similar detectability and an improved characterization of shape and contrast enhancement distribution using CEDBT.
• Suivi des glaciers de montagne par imagerie radar satellitaire
  
  • Fallourd Renaud
  • Dehecq Amaury
  • Jauvin Matthias
  • Yan Yajing
  • Vasile Gabriel
  • Gay Michel
  • Trouvé Emmanuel
  • Nicolas Jean Marie
  Revue Française de Photogrammétrie et de Télédétection, Société Française de Photogrammétrie et de Télédétection, 2019 (219-220), pp.91-105. Cet article présente un ensemble de résultats obtenus par télédétection radar satellitaire sur le site test Chamonix-Mont Blanc. L'objectif est d'illustrer le potentiel et les limitations de l'imagerie SAR (Synthetic Aperture Radar) pour l'observation des glaciers de montagne en zone tempérée. Après avoir rappelé certaines spécificités de ces glaciers qui conditionnent l'exploitation des données SAR, trois types de mesures sont étudiés : i/ le calcul de champs de déformation par interférométrie différentielle (D-InSAR) avec des données ERS Tandem dont les couplesà un jour permettaient de mettre en œuvre cette technique en dehors de la période estivale ; ii/ le calcul de champs de déformation bidimensionnels par corrélation d'amplitude avec des données haute résolution TerraSAR-X (TSX) et la reconstruction du déplacement tridimensionnelà partir de couples acquis sur des orbites ascendantes et descendantes ; iii/ le calcul de la topographieà partir de couples TanDEM-X (TDX) en évaluant les incertitudes liéesà la pénétration radar dans la neige et la glace. Enfin, nous illustrons les premiers résultats obtenus avec les données des satellites Sentinel-1 A/B, de plus faible résolution spatiale mais dont la répétitivitéà 6 jours et la gratuité ouvrent de nouvelles perspectives. Ces travaux montrentà la fois le fort potentiel de l'imagerie SAR pour observer la dynamique et les variations de volume des glaciers tout en soulignant les facteurs favorables ou limitant pour une exploitation régulière des données issues des satellites radar lancés depuis les années 90. (10.52638/rfpt.2019.471)
  DOI : 10.52638/rfpt.2019.471
• Ontology-mediated query answering over temporal and inconsistent data
  
  • Bourgaux Camille
  • Koopmann Patrick
  • Turhan Anni-Yasmin
  Semantic Web – Interoperability, Usability, Applicability, IOS Press, 2019. Stream-based reasoning systems process data stemming from different sources that are received over time. In this kind of applications, reasoning needs to cope with the temporal dimension and should be resilient against inconsistencies in the data. Motivated by such settings, this paper addresses the problem of handling inconsistent data in a temporal version of ontology-mediated query answering. We consider a recently proposed temporal query language that combines conjunctive queries with operators of propositional linear temporal logic (LTL), and consider these under three inconsistency-tolerant semantics that have been introduced for querying inconsistent description logic knowledge bases. We investigate their complexity for temporal EL ⊥ and DL-LiteR knowledge bases. In particular, we consider two different cases, depending on the presence of negations in the query. Furthermore, we complete the complexity picture for the consistent case. We also provide two approaches toward practical algorithms for inconsistency-tolerant temporal query answering. (10.3233/SW-180337)
  DOI : 10.3233/SW-180337
• Evolving, Growing, and Gardening Cyber-physical Systems
  
  • Stepney Susan
  • Diaconescu Ada
  • Doursat René
  • Giavitto Jean-Louis
  • Miller Julian
  • Spicher Antoine
  , 2019.
• Complexity of Unique (Optimal) Solutions in Graphs: Vertex Cover and Domination
  
  • Hudry Olivier
  • Lobstein Antoine
  Journal of Combinatorial Mathematics and Combinatorial Computing, Charles Babbage Research Centre, 2019, 110, pp.217-240. We study the complexity of four decision problems dealing with the uniqueness of a solution in a graph: "Uniqueness of a Vertex Cover with bounded size"(U-VC) and "Uniqueness of an Optimal Vertex Cover"(U-OVC), and for any fixed integer r ≥ 1, "Uniqueness of an r-Dominating Code with bounded size" (U-DCr) and "Uniqueness of an Optimal r-Dominating Code" (U-ODCr). In particular, we give a polynomial reduction from "Unique Satisfiability of a Boolean formula" (U-SAT
• Medical imaging and AI
  
  • Bloch Isabelle
  , 2019.
• Tree Sampling Divergence: An Information-Theoretic Metric for Hierarchical Graph Clustering
  
  • Charpentier Bertrand
  • Bonald Thomas
  , 2019. We introduce the tree sampling divergence (TSD), an information-theoretic metric for assessing the quality of the hierarchical clustering of a graph. Any hierarchical clustering of a graph can be represented as a tree whose nodes correspond to clusters of the graph. The TSD is the Kullback-Leibler divergence between two probability distributions over the nodes of this tree: those induced respectively by sampling at random edges and node pairs of the graph. A fundamental property of the proposed metric is that it is interpretable in terms of graph reconstruction. Specifically, it quantifies the ability to reconstruct the graph from the tree in terms of information loss. In particular, the TSD is maximum when perfect reconstruction is feasible , i.e., when the graph has a complete hierarchical structure. Another key property of TSD is that it applies to any tree, not necessarily binary. In particular , the TSD can be used to compress a binary tree while minimizing the information loss in terms of graph reconstruction, so as to get a compact representation of the hierarchical structure of a graph. We illustrate the behavior of TSD compared to existing metrics on experiments based on both synthetic and real datasets.
• Documenting Supermarkets: Contemporary Efforts To Support Intellectually Disturbing Organizations Food Coop (2016) -Tom Boothe Unplugged -Voices
  
  • Ouahab Alban
  M@n@gement, AIMS (Association internationale de management stratégique), 2019, 22, pp.671 - 702.
• Anytime Large-Scale Analytics of Linked Open Data
  
  • Soulet Arnaud
  • Suchanek Fabian
  , 2019. Analytical queries are queries with numerical aggregators: computing the average number of objects per property, identifying the most frequent subjects, etc. Such queries are essential to monitor the quality and the content of the Linked Open Data (LOD) cloud. Many analytical queries cannot be executed directly on the SPARQL endpoints, because the fair use policy cuts off expensive queries. In this paper, we show how to rewrite such queries into a set of queries that each satisfy the fair use policy. We then show how to execute these queries in such a way that the result provably converges to the exact query answer. Our algorithm is an anytime algorithm, meaning that it can give intermediate approximate results at any time point. Our experiments show that the approach converges rapidly towards the exact solution, and that it can compute even complex indicators at the scale of the LOD cloud.
• 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.
• On the Capacity of MIMO Optical Wireless Channels
  
  • Li Longguang
  • Moser Stefan M
  • Wang Ligong
  • Wigger Michèle
  IEEE Transactions on Information Theory, Institute of Electrical and Electronics Engineers, 2019. This paper studies the capacity of a general multiple-input multiple-output (MIMO) free-space optical intensity channel under a per-input-antenna peak-power constraint and a total average-power constraint over all input antennas. The main focus is on the scenario with more transmit than receive antennas. In this scenario, different input vectors can yield identical distributions at the output, when they result in the same image vector under multiplication by the channel matrix. We first determine the most energy-efficient input vectors that attain each of these image vectors. Based on this, we derive an equivalent capacity expression in terms of the image vector, and establish new lower and upper bounds on the capacity of this channel. The bounds match when the signal-to-noise ratio (SNR) tends to infinity, establishing the high-SNR asymptotic capacity. We also characterize the low-SNR slope of the capacity of this channel. (10.1109/ITW.2018.8613496)
  DOI : 10.1109/ITW.2018.8613496
• 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
• 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.
• 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.
• Several new classes of self-dual bent functions derived from involutions
  
  • Mesnager Sihem
  • Luo G.
  • Cao X.
  Journal of Cryptography and Communications- Discrete Structures, Boolean Functions, and Sequences, 2019.
• On q-ary plateaued functions over Fq and their explicit characterizations.
  
  • Mesnager Sihem
  • Özbudak Ferruh
  • Sinak A.
  • Cohen Gerard
  European Journal of Combinatorics, Elsevier, 2019.
• Three-Weight Minimal Linear Codes and Their Applications
  
  • Mesnager Sihem
  • Sinak A.
  • Yayla O.
  , 2019.