CITI seminar – Jean Marie GORCE (Citi) – 07/07 at 14:00

Title: On computing individual exposure risk to a pandemia with BLE-RSSI measures

Date and Place: 07 / 07 / 2020 14:00

Speaker: Jean Marie GORCE (Citi)



Abstract: Tracking how Covid-19 spreads over a population is a critical aspect that may aid relaxing lockdown conditions. Most of current solutions (e.g. as proposed in the European project PEPP-PT, the French application Stopcovid, the GAEN (Google-Apple Exposure Notification) ) rely on the RSSI signals obtained with Bluetooth Low Energy (BLE) HELLO messages. In this talk, we describe an algorithm which is complient with the constraints imposed by the rules and parameters of the ROBERT protocol developed by the Privatics team (Inria) and used in the Stopcovid application. Underlying the algorithm is mathematical modeling of the physical wireless communication link, based on real-life BLE RSSI traces. In particular, the algorithm is evaluated on experimental data obtained in the PEPP-PT project (April 2020) and lead by the Fraunhoffer institute, and experimental data aquired by the Stopcovid consortium (May, 2020) lead by Inria, both providing a large number of device-to-device BLE RSSI traces in realistic scenarios.



CITI seminar – Mario Zanon (IMT Lucca) – 30/06 at 14:00

Title: Optimal Control, MPC, and Reinforcement Learning

Date and Place: 30 / 06 / 2020 14:00

Speaker: Mario Zanon (Assistant Professor, IMT Lucca, Italy)

Host: Maracas


Abstract: Data-driven control approaches such as Reinforcement Learning (RL) mitigate the issue of model construction and controller tuning by learning directly the (optimal) control law from data. While stunning results have been obtained, RL cannot provide stability nor safety guarantees. Additionally, while partial information on the system is usually available, it can be hard to use it within RL. Model Predictive Control (MPC) is an advanced control technique able to deal with nonlinear systems subject to constraints. The main idea of MPC is to use a mathematical model of the process to predict its future behavior and minimize a given performance index. The advantages of MPC are numerous, as it makes it relatively easy to handle various difficulties in control design, such as dealing with constraints, nonlinear and hybrid dynamics, etc. One of the main drawbacks of MPC is that control performance is highly dependent on the predictive ability of the model. In this seminar, we will discuss how RL and MPC can be combined with the aim of benefitting from the advantages of each while limiting the drawbacks of both. We will introduce the two techniques and present some recent theoretical results, supported by simulation results.


Mario Zanon received the Master’s degree in Mechatronics from the University of Trento, and the Diplôme d’Ingénieur from the Ecole Centrale Paris, in 2010. After research stays at the KU Leuven, University of Bayreuth, Chalmers University, and the University of Freiburg he received the Ph.D. degree in Electrical Engineering from the KU Leuven in November 2015. He held a Post-Doc researcher position at Chalmers University until the end of 2017 and is now Assistant Professor at the IMT School for Advanced Studies Lucca. His research interests include numerical methods for optimization, economic MPC, reinforcement learning and optimal control and estimation of nonlinear dynamic systems, in particular for aerospace and automotive applications.


CITI seminar – Ioannis Krikidis (Univ. Cyprus) – 13/02 at 11:30

Title: Wireless Powered Communications: Overview, Recent Results, and Challenges

Date and Place: 13 / 02 / 2020 10:30 in TD-C

Speaker: Ioannis Krikidis (Univ. Cyprus)

Host: Maracas


Conventional energy-constrained wireless systems such as sensor networks are powered by batteries and have limited lifetime. Wireless power transfer (WPT) is a promising technology for energy sustainable networks, where terminals can harvest energy from dedicated electromagnetic radiation through appropriate electronic circuits. The integration of WPT technology into communication networks introduces a fundamental co-existence of information and energy flows; radio-frequency signals are used in order to convey information and/or energy. The efficient management of these two flows through sophisticated networking protocols, signal processing/communication techniques and network architectures, gives rise to a new communication paradigm called wireless powered communications (WPC). In this talk, we discuss the principles of WPC and we highlight its main network architectures as well as the fundamental trade-off between information and energy transfer. Several examples, which deal with the integration of WPC in modern communication systems, are presented.


Dr. Ioannis Krikidis received the diploma in Computer Engineering from the Computer Engineering and Informatics Department (CEID) of the University of Patras, Greece, in 2000, and the M.Sc and Ph.D degrees from Ecole Nationale Superieure des Telecommunications (ENST), Paris, France, in 2001 and 2005, respectively, all in electrical engineering. From 2006 to 2007 he worked, as a Post-Doctoral researcher, with ENST, Paris, France, and from 2007 to 2010 he was a Research Fellow in the School of Engineering and Electronics at the University of Edinburgh, Edinburgh, UK. He is currently an Associate Professor at the Department of Electrical and Computer Engineering, University of Cyprus, Nicosia, Cyprus. His current research interests include wireless communications, cooperative networks, 4G/5G communication systems, wireless powered communications, and secrecy communications. I. Krikidis is an IEEE Fellow (class 2019) and he has received the prestigious ERC consolidator grant.


CITI seminar – Mari Kobayashi (TU Munich) – 13/02 at 10:30

Title: Joint State Sending and Communications: Theory and Vehicular Applications

Date and Place: 13 / 02 / 2020 10:30 in TD-C

Speaker: Mari Kobayashi (TU Munich)

Host: Maracas


We consider a communication setup where transmitters wish to simultaneously sense network states and convey messages to intended receivers. The scenario is motivated by joint radar and vehicular communications where the radar and data applications share the same bandwidth. First, I present a theoretical framework to characterize the fundamental limits of such a setup for memoryless channels with i.i.d. state sequences. Then, I present our recent work on joint radar and communication using Orthogonal Time Frequency Space (OTFS). Although restricted to a simplified scenario with a single target, our numerical examples demonstrated that two modulations provide as accurate radar estimation as Frequency Modulated Continuous Waveform (FMCW), a typical automotive radar waveform, while providing a non-negligible communication rate for free.


Mari Kobayashi received the B.E. degree in electrical engineering from Keio University, Yokohama, Japan, in 1999, and the M.S. degree in mobile radio and the Ph.D. degree from École Nationale Supérieure des Télécommunications, Paris, France, in 2000 and 2005, respectively. From November 2005 to March 2007, she was a postdoctoral researcher at the Centre Tecnològic de Telecomunicacions de Catalunya, Barcelona, Spain. In May 2007, she joined the Telecommunications department at CentraleSupélec, Gif-sur-Yvette, France, where she is now a professor. She is the recipient of the Newcom++ Best Paper Award in 2010, and IEEE Comsoc/IT Joint Society Paper Award in 2011, and ICC Best Paper Award in 2019. Since September 2017, she is on a sabbatical leave at Technical University of Munich (TUM) as an Alexander von Humboldt Experienced Research Fellow (till April 2019) and August-Wihelm Scheer Visiting Professor (since August 2019).


PhD Defence: “Simultaneous Information and Energy Transmission”, Nizar Khalfet, Emilie du Chatelet Amphitheater, INSA, 13th of February 2020 at 14h


Simultaneous Information and Energy Transmission


In this thesis, the fundamental limits of simultaneous information and energy transmission (SIET) are studied from two perspectives: the asymptotic and non-asymptotic block-length regimes. In the asymptotic block-length regime, the fundamental limits on SIET in the two-user Gaussian interference channel (G-IC) with and without feedback are characterized. More specifically, an achievable and converse region in terms of information and energy transmission rates (in bits per channel use and energy-units per channel use, respectively) are identified. In both cases, with and without feedback, an achievability scheme based on power-splitting, common randomness, rate splitting, block-Markov superposition coding, and backward decoding is presented. Finally, converse regions for both cases are obtained using some of the existing outer bounds on information transmission rates, as well as a new outer bound on the energy transmission rate. For the finite block-length regime, the case of a transmitter simultaneously sending information to a receiver and energy to an energy harvester through the binary symmetric channel has been studied. Given a finite number of channel uses (latency constraint) as well as tolerable average decoding error probability and energy shortage probability (reliability constraints), two sets of information and energy

transmission rates are presented. One consists in rate pairs for which the existence of at least one code achieving such rates under the latency and reliability constraints is proved (achievable region). The second one consists in a set whose complement contains the rate pairs for which there does not exist a code capable of achieving such rates (converse region). These two sets approximate the information-energy capacity region, which allows analyzing the trade-offs among performance, latency, and reliability in SIET systems.




  • Dr. Samson Lasaulce, CNRS, France. Reviewer.
  • Dr. Ioannis Krikidis, University of Cyprus, Cyprus. Reviewer.
  • Dr. Marie Kobayashi, CentraleSupelec, France. Examiner.
  • Dr. Jean-Marie Gorce, INSA de Lyon, France. Supervisor.
  • Dr. Samir M. Perlaza, INRIA, France. Advisor.

CITI seminar – Xavier BULTEL (INSA CVL) – 30/01 at 11:00

Title: Sécurité des protocoles de jeux de levées : comment jouer au Bridge avec des tricheurs.

Date and Place: 30 / 01 / 2020 11:00 in TD-C

Speaker: Xavier Bultel (INSA CVL)

Host: Privatics

Les jeux de levées sont des jeux de cartes où chacun des joueurs pose une carte à tour de rôle en fonction d’une règle donnée. Le joueur qui a posé la carte la plus forte gagne la levée, c’est-à-dire toutes les cartes jouées durant la manche. Par exemple, Atout Pique est un jeu de levée très populaire sur les sites de casino en ligne, où chacun des joueurs doit, s’il le peut, jouer une carte de la même couleur que celle de la première carte de la manche. Dans ce genre de jeux, un joueur malhonnête peut jouer une mauvaise carte même s’il à des cartes de la bonne couleur. Comme les autres cartes sont cachées, il est impossible de détecter la triche. Les autres joueurs s’en rendront compte plus tard, lorsque le tricheur jouera une carte qu’il n’est pas sensé avoir. Dans ce cas, le jeu est biaisé et doit être annulé, et l’équipe qui a triché se voit attribuer une pénalité de paiement. cela pose problème si le partenaire du tricheur n’est pas son complice, ce qui est le cas dans les jeux en ligne puisque les joueurs sont appareillés par le serveur du site. Notre but est de proposer un protocole cryptographique qui prévient ce genre de triche. Dans ce tte présentation on définit d’abord un modèle de sécurité pour les protocoles d’Atout Pique sécurisés, puis on construit un protocole appelé SecureSpades. Ce protocole est prouvé sûr dans notre modèle sous l’hypothèse Diffie-Hellman Décisionnel, dans le modèle de l’oracle aléatoire. Notre modèle de sécurité et notre protocole peuvent être étendus à un grand nombre d’autres jeux de levées, comme la Belotte, le Bridge, le Whist, etc.

Xavier Bultel, MdC à l’INSA CVL depuis septembre 2019 ; Ex Postdoc à l’IRISA à Rennes (2018-2019) et doctorant au LIMOS à Clermont-Ferrand sous la direction de Pascal Lafourcade (2014-2018).

CITI seminar – Julien Bourgeois (Univ. Bourgogne-Franche-Comté, Institut FEMTO-ST, CNRS) – 23/01 at 14:00

Title: Building programmable matter with micro-robots

Date and Place: 23 / 01 / 2020 14:00 in TD-C

Speaker: Julien Bourgeois (Univ. Bourgogne-Franche-Comté, Institut FEMTO-ST, CNRS)

Host: Olivier Simonin

Technological advances, especially in the miniaturization of robotic devices foreshadow the emergence of large-scale ensembles of small-size resource-constrained robots that distributively cooperate to achieve complex tasks. These ensembles are formed by independent, intelligent and communicating units which act as a whole ensemble which can be used to build programmable matter i.e. matter able to change its shape.
In my talk, I will present our research effort in building Programmable Matter (PM) based on modular robots. To do this, we use micro-technology to scale down the size of each element, and we study geometry, structure, actuation, power, electronics and integration. To manage the complexity of this kind of environment, we propose a complete environment including programmable hardware, a programming language, a compiler, a simulator, a debugger and distributed algorithms.

Julien Bourgeois is a professor of computer science at the University of Bourgogne Franche-Comté (UBFC) in France. He is leading the computer science department at the FEMTO-ST institute/CNRS. His research interests include distributed intelligent MEMS (DiMEMS), Programmable Matter, P2P networks and security management for complex networks. He has worked for more than 15 years on these topics and has co-authored more than 160 international publications. He was an invited professor at Carnegie Mellon University (US) from 2012 to 2013, at Emory University (US) in 2011 and at Hong Kong Polytechnic University in 2010, 2011 and 2015. He led different funded research projects (Smart Surface, Smart Blocks, Computation and coordination for DiMEMS). He is currently leading the programmable matter project funded by the ANR and the ISITE-BFC project. He organized and chaired many conferences (dMEMS 2010, 2012, HotP2P/IPDPS 2010, Euromicro PDP 2008 and 2010, IEEE GreenCom 2012, IEEE iThings 2012, IEEE CPSCom 2012, GPC 2012, IEEE HPCC 2014, IEEE ICESS 2014, CSS 2014, IEEE CSE 2016, IEEE EUC 2015, IEEE ATC 2017, IEEE CBDCom 2017).


Journées Nationales de la Recherche en Robotique

Du 14 au 17 octobre, Olivier Simonin a co-présidé avec François Charpillet (Inria Nancy) les JNRR 2019 Journées Nationales de la Recherche en Robotique, qui se sont tenues à Vittel et parrainées par le GDR Robotique. Le 13 octobre était également organisée la Journée des Jeunes Chercheurs en Robotique JJCR, et les 17/18 un tutoriel Apprentissage & Robotique était organisé par Christian Wolf et David Filliat.

L’événement, qui a lieu tous les 2 ans, a eu un fort succès en accueillant 200 participants, qui ont pu suivre 27 exposés scientifiques sur 3 jours.

Site des JNRR 2019 (accès au programme) :

CITI seminar – John Manuel Delgado and Michael Puentes (TInteresaLab de Unidades Tecnológicas de Santander) – 22/11 at 9:00AM

Title: Pedestrian Behavior Modeling and Simulation from Real Time Data Information

Date and Place: 22 / 11 / 2019 09:00 in TD-D

Speaker: John Manuel Delgado and Michael Puentes (TInteresaLab de Unidades Tecnológicas de Santander – UTS, Colombia)

Host: Oscar Carrillo

Accidents of pedestrians sometimes take lives, in Bucaramanga since 2012 pedestrian died by accidents are 179, and 2873 hurt, In a city like Bucaramanga-Colombia, this means each day at least one pedestrian is involved in an accident. Therefore is necessary to know the causes of accidents in the way to decrease the accidents. One of many reasons to know the causes is with system dynamics, simulating the events of the Pedestrian behavior when accidents occur in risen cities. The implementation simulation joint with technology and research looking for saving lives, reducing the accidental rate, and to implementing or suggesting new policies from the government. This project is looking for the implementation of technology in video records and Deep Learning analysis for the service of the citizens, where a simulation model will be revealing the main variables which intervene in the pedestrian’s behavior. As initials results, shows the methodology here implemented, can reach data which was insufficient before thanks to the cameras and software of objects detection, those are the data input for the simulation model, which after to implement a change in a particular spot of Bucaramanga is possible to decrease the accident rate in 80% where pedestrians could be involved.


PhD Defence: “High-level synthesis and arithmetic optimizations”, Yohann Uguen, Chappe Amphitheater, CITI, 13th of November 2019 at 13h30


High-level synthesis and arithmetic optimizations


High-level synthesis (HLS) tools offer increased productivity regarding FPGA programming. However, due to their relatively young nature, they still lack many arithmetic optimizations. This thesis proposes safe arithmetic optimizations that should always be applied. These optimizations are simple operator specializations, following the C semantic. Other require to a lift the semantic embedded in high-level input program languages, which are inherited from software programming, for an improved accuracy/cost/performance ratio. To demonstrate this claim, the sum-of-product of floating-point numbers is used as a case study. The sum is performed on a fixed-point format, which is tailored to the application, according to the context in which the operator is instantiated.

In some cases, there is not enough information about the input data to tailor the fixed-point accumulator. The fall-back strategy used in this thesis is to generate an accumulator covering the entire floating-point range. This thesis explores different strategies for implementing such a large accumulator, including new ones. The use of a 2’s complement representation instead of a sign+magnitude is demonstrated to save resources and to reduce the accumulation loop delay.

Based on a tapered precision scheme and an exact accumulator, the posit number systems claims to be a candidate to replace the IEEE floating-point format. A throughout analysis of posit operators is performed, using the same level of hardware optimization as state-of-the-art floating-point operators. Their cost remains much higher that their floating-point counterparts in terms of resource usage and performance.

Finally, this thesis presents a compatibility layer for HLS tools that allows one code to be deployed on multiple tools. This library implements a strongly typed custom size integer type along side a set of optimized custom operators.



  • Philippe Coussy, Professeur des Universités, UBS, Lorient, France : Rapporteur
  • Olivier Sentieys, Professeur des Universités, Univ. Rennes, Inria, IRISA, Rennes : Rapporteur
  • Laure Gonnord, Maître de conférence, Université Lyon 1, France : Examinatrice
  • Frédéric Pétrot, Professeur des Universités, TIMA, Grenoble, France : Examinateur
  • Martin Kumm, Professeur des Universités, Université de Fulda, Allemagne : Examinateur
  • Florent de Dinechin, Professeur des Universités, INSA Lyon, France : Directeur de thèse