Publications

2020

• Codebooks from generalized bent Z4-valued quadratic forms
  
  • Qi Y.
  • Mesnager Sihem
  • Tang C.
  Discrete Mathematics, Elsevier, 2020.
• Pythagore, J'adore
  
  • Zayana Karim
  Repères IREM, IREM, 2020. Ce texte reprend la trame d'un atelier proposé en avril-mai 2019 à Besançon pour le cinquantenaire des IREM, à Paris dans le cadre d'un plan national de formation, ainsi que dans les INSPÉ de Grenoble, Lyon et Nantes auprès des professeurs stagiaires (mathématiques et math-sciences). Il propose une étude, circonscrite aux programmes du second degré et à l'aune d'un questionnement QQOQCP 1 , de l'oeuvre de Pythagore. Flânons ainsi entre histoire, géographie, physique, musique, philosophie et bien sûr mathématiques... par Karim Zayana Inspecteur général, professeur invité à l'institut Mines-Télécom Avec esprit, humour et un zeste d'impertinence, on l'a mis en rap [1] et on l'a mis par terre [2] tandis qu'il nous mettait en pleurs [3]. En chanson, les artistes Isaaba, Renaud ou Aldebert, font rimer Pythagore sur nos chagrins d'école. Le grand homme ne sonne pourtant pas qu'avec « hardcore » et « mort »… À notre tour, dansons sur son trésor qui, charrié par les siècles, voyagea jusqu'à nous. L'exercice est plus sérieux qu'il y paraît, la simplicité d'un théorème, fût-il enfantin, n'est souvent qu'illusion. En savourer les mille et un reflets, en saisir l'essence, embrasser sa richesse reste un chemin ardu. La compréhension naît de l'effort, puis le plaisir de la compréhension. Là est la délivrance, point d'orgue culminant d'un processus long et sinueux qu'Heidegger résume en deux mots, chercher et questionner : « Tout questionner est un chercher. Tout chercher tire de ce qu'il recherche la direction qui précède et guide sa démarche. Questionner, c'est, sur le plan de la connaissance, chercher l'élément quant au fait qu'il soit et quant à son être tel. Chercher, sur le plan de la connaissance, s'appelle " recherche " quand est dégagé pour le déterminer ce après quoi la question se pose. » [4]. Toute la difficulté de trouver un sens aux choses est ici rendue par cette phrase, aussi complexe qu'abstraite. Il en va de même pour qui veut apprécier les mathématiques. Heureusement nous disposons d'outils. L'angle pédagogique des compétences en est un, et nous pourrions interroger en quoi la science des pythagoriciens les valide ou les développe, de calculer à communiquer en passant par modéliser sans oublier les facultés raisonner, représenter, chercher qu'il est d'usage d'effeuiller telles les pétales d'une fleur [5]. Une autre approche, que nous privilégions ici, relève de la méthodologie scientifique. Quand un chercheur analyse un problème, il le soumet un jour ou l'autre à ce crible [6] : 1. C'est de Qui, c'est Quand, c'est Où ? 1 Qui, Quand, Où, Quoi, Comment, Combien, Pour quoi/qui. Méthode empirique de questionnement circonstancié très utilisée en journalisme (de façon consciente), mais aussi en R&D (de façon sans doute moins formalisée).
• Private free-space communications based on chaos synchronization of mid-infrared quantum cascade laser light
  
  • Spitz O
  • Herdt A
  • Wu J
  • Wong C.-W
  • Elsässer W
  • Grillot F
  , 2020. Free Space Optics (FSO) is a growing technology offering higher bandwidth with fast and cost-effective deployment compared to fiber technology. This work demonstrates private free-space communication with quantum cascade lasers (QCLs). The secret message is encoded into a chaotic waveform so that the information is hard for an eavesdropper to extract [1]. Chaos-based transmissions in FSO are fundamentally restricted by atmospheric phenomena (e.g., turbulence, fog or scattering). Thus, the operating wavelength is a key parameter that has to be chosen wisely to reduce the impact of the environmental parameters. In this context, QCLs are relevant semiconductor lasers because their optical wavelength lies within mid-infrared domains where the atmosphere is highly transparent [2]. The simplest way to generate a chaotic optical carrier from a QCL is to feed back part of its emitted light into the device after a certain time delay [3], beyond which chaos synchronization between the drive and the response QCLs occurs.
• Real Time Multiscale Rendering of Dense Dynamic Stackings
  
  • Michel Elie
  • Boubekeur Tamy
  Computer Graphics Forum, Wiley, 2020, 39 (7), pp.169-179. Dense dynamic aggregates of similar elements are frequent in natural phenomena and challenging to render under full real time constraints. The optimal representation to render them changes drastically depending on the distance at which they are observed, ranging from sets of detailed textured meshes for near views to point clouds for distant ones. Our multiscale representation use impostors to achieve the mid-range transition from mesh-based to point-based scales. To ensure a visual continuum, the impostor model should match as closely as possible the mesh on one side, and reduce to a single pixel response that equals point rendering on the other. In this paper, we propose a model based on rich spherical impostors, able to combine precomputed as well as dynamic procedural data, and offering seamless transitions from close instanced meshes to distant points. Our approach is architectured around an on-the-fly discrimination mechanism and intensively exploits the rough spherical geometry of the impostor proxy. In particular, we propose a new sampling mechanism to reconstruct novel views from the precomputed ones, together with a new conservative occlusion culling method, coupled with a two-pass rendering pipeline leveraging early-Z rejection. As a result, our system scales well and is even able to render sand, while supporting completely dynamic stackings. (10.1111/cgf.14135)
  DOI : 10.1111/cgf.14135
• La théorie de l'information
  
  • Rioul Olivier
  , 2020, pp.7.
• A lightweight ECC-based authentication scheme for Internet of Things (IoT)
  
  • Hammi Badis
  • Fayad Achraf
  • Khatoun Rida
  • Zeadally Sherali
  IEEE Systems Journal, IEEE, 2020. (10.1109/JSYST.2020.2970167)
  DOI : 10.1109/JSYST.2020.2970167
• Discrete and stochastic coalitional storage games
  
  • Kiedanski Diego
  • Orda Ariel
  • Kofman Daniel
  , 2020. To achieve a fully decarbonized power grid, a massive deployment of renewable energy resources will be needed, but because of the intermittent nature of their generation, their full potential will not be unleashed unless demand side flexibility plays a bigger role than today. Introducing energy storage at the residential level enables increasing load flexibility, as it allows end-customers to easily change their consumption profile and adapt to the grid requirements. As of today, energy storage for residential consumers represents a considerable investment that is not guaranteed to be profitable. Shared investment models in which a group of consumers jointly acquires energy storage have been proposed in the literature to increase the attractiveness of these devices. Such models naturally employ concepts of cooperative game theory. In this paper, we extend the state-of-the-art cooperative game for modeling the shared investment in storage by adding two crucial extensions: stochasticity of the load and discreetness of the storage device capacity. As our goal is to increase storage capacity in the grid, the number of devices that would be acquired by a group of players that cooperate according to our proposed scheme is compared to the number of devices that would be bought by consumers acting individually. Under the same criteria of customer profitability , simulations using real data reveal that our proposed scheme can increase the deployed storage capacity between 100% and 250%. (10.1145/3396851.3397729)
  DOI : 10.1145/3396851.3397729
• Minimal linear codes from characteristic functions
  
  • Mesnager Sihem
  • Qi Y.
  • Ru H.
  • Tang C.
  IEEE Transactions on Information Theory, Institute of Electrical and Electronics Engineers, 2020.
• Improving Interpretability for Computer-aided Diagnosis tools on Whole Slide Imaging with Multiple Instance Learning and Gradient-based Explanations
  
  • Pirovano A.
  • Heuberger H.
  • Berlemont S.
  • Ladjal S.
  • Bloch Isabelle
  , 2020, LNCS 12446, pp.43-53.
• From Interferometric to Tomographic Synthetic Aperture Radar. Scatterer unmixing in urban areas: A review of synthetic aperture radar tomography-processing techniques
  
  • Rambour Clement
  • Budillon Alessandra
  • Johnsy Angel
  • Denis Loïc
  • Tupin Florence
  • Schirinzi Gilda
  IEEE geoscience and remote sensing magazine, IEEE, 2020, 8 (2).
• La transmission « naturelle » des savoirs
  
  • Dessalles Jean-Louis
  , 2020, pp.49-58. Les sociétés de chasseurs-cueilleurs n'ont pas d'écoles. Elles accumulent pourtant des savoirs, elles possèdent des langues et des cultures sophistiquées. Si l'on compare notre espèce aux autres primates, tout est différent. Les cultures animales existent, mais elles sont si restreintes qu'elles sont longtemps passées inaperçues aux yeux des éthologues. Pourquoi existe-t-il tant de « savoirs » dans notre espèce ? Et pourquoi les transmettons-nous ? Si la question semble saugrenue, c'est parce que nous avons perdu de vue le caractère apparemment contre-nature de ce comportement. Un comportement contre-nature Les chimpanzés étudiés par l'éthologue Tetsuro Matsuzawa [1994] dans la forêt de Bossou, en Guinée, cassent spontanément des noix très dures en posant la noix sur une pierre (l'enclume) et en frappant avec une autre pierre (le marteau). Leur expertise demande des années d'imitation des congénères. Les jeunes l'acquièrent en explorant un peu au hasard des centaines de combinaisons de paramètres : choix des pierres, position de l'enclume, face et angle de frappe, etc. Les adultes sont très bienveillants vis-à-vis des jeunes qui les observent, mais on ne les voit jamais leur montrer activement le bon geste et encore moins intervenir lorsqu'ils font des erreurs à répétition. L'espèce humaine offre un contraste saisissant. Prenons l'exemple des forums techniques. Imaginons un étudiant qui apprend le langage informatique Python et cherche à savoir comment inverser une liste. Il tape « python reverse list » sur son moteur de recherche et arrive sur un forum comme Stackoverflow. Il constate que sa question a déjà été posée par un autre débutant et qu'elle a obtenu 29 réponses qui ont elles-mêmes reçu 34 commentaires. Les personnes qui ont pris la peine de répondre ne connaissent pas l'étudiant. Elles font partie d'une communauté, celle des programmeurs Python, au sein de laquelle l'entraide spontanée est considérée comme normale. Paru dans : P. Pion & N. Schlanger (Eds.), Apprendre-Archéologie de la transmission des savoirs, pp. 49-58. Paris: La Découverte, 2020.
• « Je dois y aller ». Analyses de séquences de clôtures entre humains et robot
  
  • Licoppe Christian
  • Rollet Nicolas
  Réseaux : communication, technologie, société, Lavoisier, La Découverte, 2020, N°220-221 (2), pp.151. (10.3917/res.220.0151)
  DOI : 10.3917/res.220.0151
• Complexity of voting procedures
  
  • Hudry Olivier
  , 2020.
• The Compared Costs of Domination, Location-Domination and Identification
  
  • Hudry Olivier
  • Lobstein Antoine
  Discussiones Mathematicae Graph Theory, University of Zielona Góra, 2020, 40 (1), pp.127-147. Let G = (V, E) be a finite graph and r ≥ 1 be an integer. For v ∈ V , let B r (v) = {x ∈ V : d(v, x) ≤ r} be the ball of radius r centered at v. A set C ⊆ V is an r-dominating code if for all v ∈ V , we have B r (v) ∩ C = ∅; it is an r-locating-dominating code if for all v ∈ V , we have B r (v) ∩ C = ∅, and for any two distinct non-codewords x ∈ V \ C, y ∈ V \ C, we have B r (x) ∩ C = B r (y) ∩ C; it is an r-identifying code if for all v ∈ V , we have B r (v) ∩ C = ∅, and for any two distinct vertices x ∈ V , y ∈ V , we have B r (x) ∩ C = B r (y) ∩ C. We denote by γ r (G) (respectively, ld r (G) and id r (G)) the smallest possible cardinality of an r-dominating code (respectively, an r-locating-dominating code and an r-identifying code). We study how small and how large the three differences id r (G)−ld r (G), id r (G)−γ r (G) and ld r (G) − γ r (G) can be. (10.7151/dmgt.2129)
  DOI : 10.7151/dmgt.2129
• phiflow: A Differentiable PDE Solving Framework for Deep Learning via Physical Simulations
  
  • Holl Philipp
  • Koltun Vladlen
  • Um Kiwon
  • Thuerey Nils
  , 2020.
• Real-Time Deformation with Coupled Cages and Skeletons
  
  • Corda F
  • Thiery J M
  • Livesu M
  • Puppo E
  • Boubekeur T
  • Scateni R
  Computer Graphics Forum, Wiley, 2020. Skeleton-based and cage-based deformation techniques represent the two most popular approaches to control real-time deformations of digital shapes and are, to a vast extent, complementary to one another. Despite their complementary roles, high-end modelling packages do not allow for seamless integration of such control structures, thus inducing a considerable burden on the user to maintain them synchronized. In this paper, we propose a framework that seamlessly combines rigging skeletons and deformation cages, granting artists with a real-time deformation system that operates using any smooth combination of the two approaches. By coupling the deformation spaces of cages and skeletons, we access a much larger space, containing poses that are impossible to obtain by acting solely on a skeleton or a cage. Our method is oblivious to the specific techniques used to perform skinning and cage-based deformation, securing it compatible with pre-existing tools. We demonstrate the usefulness of our hybrid approach on a variety of examples. (10.1111/cgf.13900)
  DOI : 10.1111/cgf.13900
• Donsker's theorem in {Wasserstein}-1 distance
  
  • Coutin Laure
  • Decreusefond Laurent
  Electronic Communications in Probability, Institute of Mathematical Statistics (IMS), 2020, 25, pp.1--13. We compute the Wassertein-1 (or Kantorovitch-Rubinstein) distance between a random walk in $R^d$ and the Brownian motion. The proof is based on a new estimate of the Lipschitz modulus of the solution of the Stein's equation. As an application, we can evaluate the rate of convergence towards the local time at 0 of the Brownian motion. (10.1214/20-ECP308)
  DOI : 10.1214/20-ECP308
• A Proof of the Beierle-Kranz-Leander Conjecture related to Lightweight Multiplication in $F_2^n$
  
  • Mesnager Sihem
  • Kim K. H.
  • Jo D.
  • Choe J.
  • Han M.
  • Lee D. N.
  Journal of Designs, Codes, and Cryptography, 2020.
• Computing and Illustrating Query Rewritings on Path Views with Binding Patterns
  
  • Romero Julien
  • Preda Nicoleta
  • Amarilli Antoine
  • Suchanek Fabian
  , 2020. In this system demonstration, we study views with binding patterns, which are a formalization of REST Web services. Such views are database queries that can be evaluated using the service, but only if values for the input variables are provided. We investigate how to use such views to answer a complex user query, by rewriting it as an execution plan, i.e., an orchestration of calls to the views. In general, it is undecidable to determine whether a given user query can be answered with the available views. In this demo, we illustrate a particular scenario studied in our earlier work [11], where the problem is not only decidable, but has a particularly intuitive graphical solution. Our demo allows users to play with views defined by real Web services, and to animate the construction of execution plans visually. (10.1145/3340531.3417431)
  DOI : 10.1145/3340531.3417431
• On the number of the rational zeros of linearized polynomials and the second-order nonlinearity of cubic Boolean functions.
  
  • Mesnager Sihem
  • Kim K.H.
  • Jo. M.S.
  Cryptography and Communications- Discrete Structures, Boolean Functions, and Sequences (CCDS),, 2020.
• Low Complexity MIMO Detection for CDL Mitigation in Multi-Core Fiber Transmission
  
  • Abouseif Akram
  • Rekaya-Ben Othman Ghaya
  • Jaouën Yves
  , 2020.
• A Fundamental Storage-Communication Tradeoff for Distributed Computing with Straggling Nodes
  
  • Yan Qifa
  • Wigger Michèle
  • Yang Sheng
  • Tang Xiaohu
  IEEE Transactions on Communications, Institute of Electrical and Electronics Engineers, 2020. Placement delivery arrays for distributed computing (Comp-PDAs) have recently been proposed as a framework to construct universal computing schemes for MapReduce-like systems. In this work, we extend this concept to systems with straggling nodes, i.e., to systems where a subset of the nodes cannot accomplish the assigned map computations in due time. Unlike most previous works that focused on computing linear functions, our results are universal and apply for arbitrary map and reduce functions. Our contributions are as follows. Firstly, we show how to construct a universal coded computing scheme for MapReduce-like systems with straggling nodes from any given Comp-PDA. We also characterize the storage and communication loads of the resulting scheme in terms of the Comp-PDA parameters. Then, we prove an information-theoretic converse bound on the storage-communication (SC) tradeoff achieved by universal computing schemes with straggling nodes. We show that the information-theoretic bound matches the performance achieved by the coded computing schemes with straggling nodes corresponding to the Maddah-Ali and Niesen (MAN) PDAs, i.e., to the Comp-PDAs describing Maddah-Ali and Niesen's coded caching scheme. Interestingly, the MAN-PDAs are optimal for any number of straggling nodes. This implies that the map phase of optimal coded computing schemes does not need to be adapted to the number of stragglers in the system. We show that the points that lie exactly on the fundamental SC tradeoff cannot be achieved with Comp-PDAs that require smaller number of files than the MAN-PDAs. This is however possible for some of the points that lie close to the SC tradeoff. For these latter points, the decrease in the requested number of files can be exponential in the number of nodes of the system. We also model the total execution time, and numerically show that the active set size should be chosen to balance the duration of the map phase and the durations of the shuffle and reduce phases. (10.1109/TCOMM.2020.3020549)
  DOI : 10.1109/TCOMM.2020.3020549
• Estimation of the Ricean K Factor in the presence of shadowing
  
  • Leturc Xavier
  • Ciblat Philippe
  • Le Martret Christophe J.
  IEEE Communications Letters, Institute of Electrical and Electronics Engineers, 2020, 24 (1), pp.108-112. We address the estimation of the Ricean K factor when the available complex channel samples are noisy and subject to Nakagami-m shadowing, i.e., the line-of-sight component is modeled as a Nakagami-m random variable. We propose two estimators: one based on the expectation-maximization (EM) procedure, and a second one based on the method of moment (MoM). The MoM estimator can be used to initialize the EM procedure. We show by simulations that the two proposed estimators outperform the existing ones. (10.1109/LCOMM.2019.2950027)
  DOI : 10.1109/LCOMM.2019.2950027
• Multi-Layer HARQ with Delayed Feedback
  
  • Khreis Alaa
  • Bassi Francesca
  • Ciblat Philippe
  • Duhamel Pierre
  IEEE Transactions on Wireless Communications, Institute of Electrical and Electronics Engineers, 2020. In order to improve the transmission reliability in current wireless communication systems, the Hybrid Automatic ReQuest (HARQ) protocol is employed to manage the unknown time-varying channel. The acknowledgments are fed back with delay on the return link. To fill up the idle time between a transmission and its acknowledgment, parallel HARQ streams associated with different messages are carried out. In this paper we improve on parallel HARQ by proposing a multi-layer HARQ protocol (also called superposition coding or multi-packet HARQ), where a single transmission may carry information on multiple messages. The multi-layer HARQ protocol works in presence of delay on the return link as parallel HARQ does, and does not require additional feedback such as the channel state information. It aims at improving the accuracy as well as the user's delay distribution, thus achieving throughput increase. Assuming capacity-achieving codes, we show that the proposed protocol outperforms parallel HARQ in throughput, message error rate, and delay distribution. Using practical codes and decoding algorithms the gains are as well significant, at the expense of the receiver's complexity. (10.1109/TWC.2020.3001420)
  DOI : 10.1109/TWC.2020.3001420
• Magnetic Tunnel Junction Applications
  
  • Maciel Nilson
  • Marques Elaine
  • Naviner Lirida
  • Zhou Yongliang
  • Cai Hao
  Sensors, MDPI, 2020, 20 (1), pp.121. Spin-based devices can reduce energy leakage and thus increase energy efficiency. They have been seen as an approach to overcoming the constraints of CMOS downscaling, specifically, the Magnetic Tunnel Junction (MTJ) which has been the focus of much research in recent years. Its nonvolatility, scalability and low power consumption are highly attractive when applied in several components. This paper aims at providing a survey of a selection of MTJ applications such as memory and analog to digital converter, among others. (10.3390/s20010121)
  DOI : 10.3390/s20010121