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

 

Abstract:
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.

 

Biography:
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

 

Abstract:
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.

 

Biography:
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

Title

Simultaneous Information and Energy Transmission

Abstract

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.

 

 

Jury

  • 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

Abstract:
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.

Biography:
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

Abstract:
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.

Biography:
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) : https://jnrr2019.loria.fr/


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

Abstract:
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

Title

High-level synthesis and arithmetic optimizations

Abstract

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.

 

Jury

  • 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

CITI seminar – Martin Kumm (University of Applied Sciences Fulda, Germany) – 13/11 at 10:30AM

Title: Design of Optimal Multiplierless FIR Filters

Date and Place: 13 / 11 / 2019 10:30 in TD-C

Speaker: Martin Kumm (University of Applied Sciences Fulda, Germany)

Host: Florent de Dinechin

Abstract:
In this talk we present a novel method for the simultaneous design of digital filters adhering to a given frequency specification and its dedicated (hardware) implementation. Our methods are based on an integer linear programming (ILP) problem and aim to minimize the number of adders used to implement a digital filter. In the first part, an overview is given about the structure of finite impulse response (FIR) filters which typically contain many costly multiplications. As these are usually multiplications by a constant, they can be reduced to additions, subtractions and bit-shifts, leading to a multiplierless realization. A brief overview of state-of-the-art methods for optimizing constant multiplications is presented. In the second part, novel extensions are presented that also consider the frequency specification of the digital filter in the optimization. Compared to previous multiplierless FIR approaches, the methods introduced here ensure adder count optimality. We show the effectiveness by solving established design problems: our results either prove existing heuristics to be optimal or improve their adder count.

Biography:
Martin Kumm is full professor in the faculty of Applied Computer Science at the University of Applied Sciences Fulda in Germany. His research interests are arithmetic circuits and their optimization in the context of reconfigurable systems (FPGAs). http://www.martin-kumm.de/


CITI Seminar of Erwan Le Merrer / Gilles Tredan (Inria-Rennes / LAAS-CNRS) on October 9 at 3pm

Title: The Bouncer Problem: Challenges to Remote Explainability

Date and Place: 09 / 10 / 2019 3PM in 432 (Antenne Inria)

Host: Privatics

Abstract:
The concept of explainability is envisioned to satisfy society’s demands for transparency on machine learning decisions. The concept is simple: like humans, algorithms should explain the rationale behind their decisions so that their fairness can be assessed. While this approach is promising in a local context (e.g. to explain a model during debugging at training time), we argue that this reasoning cannot simply be transposed in a remote context, where a trained model by a service provider is only accessible through its API. This is problematic as it constitutes precisely the target use-case requiring transparency from a societal perspective. Through an analogy with a club bouncer (which may provide untruthful explanations upon customer reject), we show that providing explanations cannot prevent a remote service from lying about the true reasons leading to its decisions.

More precisely, we prove the impossibility of remote explainability for single explanations, by constructing an attack on explanations that hides discriminatory features to the querying user. We provide an example implementation of this attack. We then show that the probability that an observer spots the attack, using several explanations for attempting to find incoherences, is low in practical settings. This undermines the very concept of remote explainability in general.

Biography:
Erwan is on an “advanced research position” at Inria, in the WIDE team, since Nov. 2018. He was previously senior research scientist at Technicolor R&I (2009-2018). Gilles is a “chargé de recherches” at CNRS since 2011.