CITI @The Conversation

The laboratory gets attached to engage in dialogue with society by explaining news from the university community and the world of research. Several citizens have published articles in TheConversation newspaper:

PhD Defence: “Exact and anytime heuristic search for the Time Dependent Traveling Salesman Problem with Time Windows”, Romain Fontaine, Amphi Chappe/Lamarr Building, 9th of June 2023 at 10 AM

The defense will take place on Tuesday 9th June (morning) in the Heidi Lamarr building (Amphi Chappe), Insa-Lyon, Villeurbanne.


Exact and anytime heuristic search for the Time Dependent Traveling Salesman Problem with Time Windows


The Time Dependent (TD) Traveling Salesman Problem (TSP) is a generalization of the TSP which allows one to take traffic conditions into account when planning tours in an urban context: travel times between points to visit depend on departure times instead of being constant. The TD-TSPTW further generalizes this problem by adding Time Window constraints, i.e., constraints on visit times. Existing exact approaches such as Integer Linear Programming and Dynamic Programming usually do not scale well; heuristic approaches scale better but provide no guarantees on solution quality.

In this thesis, we introduce a new exact and anytime solving approach for the TD-TSPTW which aims at quickly providing approximate solutions and gradually improving them until proving optimality. We first show how to reduce the TD-TSPTW to the search for a best path in a state-transition graph. We provide an overview of existing search algorithms, with a focus on exact and anytime extensions of A*, and introduce a new one by hybridizing two of them. We show how to combine these exact and anytime search algorithms with local search – in order to faster find solutions of higher quality – and with bounding and time window constraint propagation – in order to filter the search space. Finally, we provide extensive experimental results to (i) validate our main design choices, (ii) compare our approach to state-of-the-art solving approaches on various TD benchmarks with different degrees of realism and different temporal granularities and (iii) compare TD solving approaches to recent TSPTW solvers on constant benchmarks. These experimental results show us that our approach offers a good compromise between the time needed to find good solutions and the time needed to find optimal solutions and prove their optimality for both TD and constant TSPTW instances.


      • Cédric PRALET, Directeur de Recherche, ONERA – Rapporteur
      • Pierre SCHAUS, Professeur des Universités, UC Louvain – Rapporteur
      • Romain BILLOT, Professeur des Universités, IMT Atlantique – Examinateur
      • Christine SOLNON Professeure des Universités, INSA Lyon – Directrice de thèse
      • Jilles S. DIBANGOYE, Maître de Conférences HDR, University of Groningen – Co-directeur de thèse

HDR Defence: “Contributions to Wireless Sensor Networks for Air Quality Monitoring”, Walid Bechkit, 24nd of May 2021 at 10AM, Lamarr Building, Insa-Lyon

The defense will take place on Friday 24th May at 10AM in the Heidi Lamarr building, Insa-Lyon, Villeurbanne.


Contributions to Wireless Sensor Networks for Air Quality Monitoring


In this talk, I will present a summary of my research, which revolves around the design and evaluation of novel solutions for Wireless Sensor Networks to efficiently monitor physical phenomena. I have addressed several scientific and technical issues by adopting a global methodology combining theoretical solutions and experimental developments. Although our solutions can be easily adapted to different applications, the focus was on air quality monitoring, a major societal challenge where new low-cost sensing technologies offer a significant advantage over traditional solutions.

This talk focuses on our main contributions in this area of low-cost sensor networks for environmental monitoring. It is structured around three axes: i) static sensor networks for air quality monitoring in cities and on industrial sites; ii) participatory sensing of air quality and Urban Heat Islands; and iii) UAV fleets for monitoring highly dynamic phenomena. The common thread running through all our solutions is that they take into account both the physical domain knowledge and the characteristics of low-cost sensors such as the limited and heterogeneous measurement accuracy. I will conclude this talk by discussing some personal feedback and setting out some future perspectives.


    • Aline CARNEIRO VIANA, Directrice de recherche, INRIA, Reviewer
    • Andrzej DUDA, Professeur, Grenoble INP – Ensimag, Reviewer
    • Nathalie MITTON, Directrice de recherche, INRIA, Reviewer
    • André-luc BEYLOT, Professeur, Toulouse INP – ENSEEIHT, Examiner
    • Abdelmadjid BOUABDALLAH, Professeur, Université de Technologie de Compiègne, Examiner
    • Isabelle GUERIN-LASSOUS, Professeur, Université de Lyon 1, Examiner
    • Hervé RIVANO, Professeur, INSA-Lyon, Examiner (« Garant »)
    • Mouloud KOUDIL, Professeur, ESI-Alger, Guest Examiner

PhD Defence: “Programming language abstractions for the Internet of Things era”, Patrik Fortier, East amphitheater of the humanities building, 22th of May 2024 at 10 AM

The defense will take place on Tuesday 22th May at 10 AM in the East amphitheater of the humanities building, Insa-Lyon, Villeurbanne.


Programming language abstractions for the Internet of Things era


Les défis par l’Internet des objets (IoT) exigent des applications modernes qu’elles gèrent d’importants volumes de données provenant de réseaux de capteurs, qui sont ensuite traités, stockés et analysés. Les développeurs ont adopté l’architecture microservices pour répondre aux problèmes passage à l’échelle et faciliter un processus de livraison rapide des logiciels. Cependant, de nouveaux paradigmes tels que le Fog et l’Edge computing introduisent diverses ressources et configurations, ce qui oblige les développeurs à s’adapter à des environnements et des écosystèmes de plus en plus complexes. L’émergence des modèles Function-as-a-Service et Serverless a mis l’accent sur une simplification du code. Cependant, cela soulève des problématiques lorsque les développeurs créent désormais des applications pour des infrastructures sur lesquelles ils n’ont qu’un contrôle limité. Dans les environnements à ressources limitées tels que l’edge computing, les applications sont en concurrence pour les ressources. Par conséquent, les développeurs ont besoin d’outils adaptés avec des abstractions appropriées pour relever les défis modernes tout en réduisant la complexité des applications.
Dans cette thèse, nous présentons des abstractions de langage de programmation adaptées au développement de logiciels distribués à l’ère de l’Internet des Objets. Nous avons consolidé ces abstractions dans un framework qui permet la construction d’applications distribuées de type “data flow” sous la forme de microservices, le tout dans le même code source. Ce framework abstrait à la fois l’infrastructure sous-jacente sur laquelle les applications s’exécutent et la communication entre les services. Nous démontrons  que notre approche  n’introduit pas de surcoût encombrante et la comparons avec les plateformes Function-as-a-Service de l’industrie.
Pour offrir un contrôle précis sur l’infrastructure, nous introduisons des primitives de langage et un moteur d’exécution local qui gère les informations contextuelles sur le cluster. En outre, nous introduisons l’entropie en tant que métrique de placement innovante pour les applications. Les développeurs peuvent dicter la manière dont ils souhaitent que leur application soit positionnée dans le cluster et comment elle doit répondre à des scénarios tels que la contention des ressources entre les applications partageant la même infrastructure. Ces techniques permettent à l’utilisateur de définir une politique de placement dynamique avec un haut niveau de granularité dans un environnement dont il n’a pas forcément le contrôle total.


      • Mme Stéphanie CHOLLET, Maître de conférences HDR – ESISAR Grenoble INP – Rapporteure
      • M. Stéphane DUCASSE, Directeur de Recherche – INRIA – Rapporteur
      • M. Philippe ROOSE, Professeur des Universités – Université de Pau et des Pays de l’Adour – Examinateur
      • M. Yannick LOISEAU, Maître de Conférences – Université Clermont Auvergne – Examinateur
      • M. Frédéric LE MOUËL, Professeur des universités – INSA Lyon – Directeur de thèse
      • M. Julien PONGE, Docteur – Red Hat – co-encadrant de thèse

CITI seminar – Edward Knightly (Rice University) – 23/05 at 10AM

Speaker: Edward Knightly (Rice University)

Date: 23/05/2024

Time: 10AM

Place: Amphi Chappe/Lamarr, 6 avenue des arts, La Doua Campus

Title: Curved Beams, Flying Metasurfaces, and Emerging Capabilities for 6G

Abstract: Next-generation wireless networks promise unprecedented performance by exploiting wide bandwidths available in millimeter wave to sub-Terahertz spectrum. At such frequencies, transmission is necessarily highly directive in order to overcome path loss. In this talk, I will debunk two myths about such networks: the first myth is that intelligent surfaces or smooth specular-reflecting surfaces are required to overcome blocked paths via reflected paths. Instead, I will show the theory and experimental results for curving beams around obstacles. The second myth is that highly directional rooftop backhaul links are inherently immune to interception by an eavesdropper. Instead, I will show the theory and experimental results for intercepting a roof-top sub-THz backhaul link without detection by using a metasurface-equipped UAV.

Bio: Edward Knightly is the Sheafor–Lindsay Professor of Electrical and Computer Engineering and Computer Science at Rice University. He received his Ph.D. and M.S. from the University of California at Berkeley and his B.S. from Auburn University. He is an ACM Fellow, an IEEE Fellow, and a Sloan Fellow. He received the IEEE INFOCOM Achievement Award, the Dynamic Spectrum Alliance Award for Research on New Opportunities for Dynamic Spectrum Access, the George R. Brown School of Engineering Teaching + Research Excellence Award, and the National Science Foundation CAREER Award. He won eight best paper awards including ACM MobiCom, ACM MobiHoc, IEEE Communications and Network Security, and IEEE INFOCOM. He serves as an editor-at-large for IEEE/ACM Transactions on Networking and serves on the scientific council of IMDEA Networks in Madrid and the scientific advisory board of INESC TEC in Porto. He served as the Rice ECE department chair from 2014 to 2019.

CITI seminar – Victor Morel (Chalmers University of Technology) – 18th March 2024 at 2PM

Speaker: Victor Morel (Chalmers University of Technology)

Date: 18th March 2024

Time: 2PM

Place: Meeting Room, 4th floor, Inria building (Antenne), La Doua Campus

Title: Of cookies and paywalls 

Abstract: Cookie paywalls allow visitors of a website to access its content only after they make a choice between paying a fee or accept tracking. European Data Protection Authorities (DPAs) recently issued guidelines and decisions on paywalls lawfulness, but it is yet unknown whether websites comply with them.
We studied the prevalence of cookie paywalls on the top one million websites using an automatic crawler. We identified 431 cookie paywalls, all using the Transparency and Consent Framework (TCF). We then analysed the data these paywalls communicate through the TCF, and in particular, the legal grounds and the purposes used to collect personal data. We observed that cookie paywalls extensively rely on legitimate interest legal basis systematically conflated with consent. We also observed a lack of correlation between the presence of paywalls and legal decisions or guidelines by DPAs. Following the publication of the paper, we disseminated our results to several legal bodies in the EU, in order to contribute to the debate surrounding the last move of Meta to propose a similar ‘pay-or-okay’ business model for Facebook and Instagram.

Bio: Victor Morel is currently working as a postdoctoral researcher in the Security & Privacy Lab at Chalmers University of Technology on usable privacy for IoT applications. He holds a PhD in computer science from Inria – Privatics. His research interests include privacy and data protection, networks security, usability and Human-Computer Interactions, applied cryptography, and ethics of technology in a broad manner. He is also a selected member of the EDPB’s support pool of experts. He appreciates sober, hackable, and accessible technology that works. Besides his academic activities, he is a member of FELINN’s collegiate council, a French association (1901) defending decentralization, privacy, and free software through popular education.


Conférence Archipel 2024 – du 15 au 18 avril 2024, Insa Lyon (appel à communications ouvert jusqu’au 8 novembre)

Dans le cadre des dégradations globales actuelles (écosystémiques, climatiques, sociales ou politiques), nos sociétés humaines se trouvent confrontées à des enjeux toujours plus pressants. La conférence Archipel a pour objectif de constituer une communauté scientifique francophone s’attachant à faire émerger les questionnements, les cadres de pensée, les méthodes et les outils permettant de traiter des risques systémiques, et plus globalement de penser les futurs de nos sociétés.
Appel à communications (ouvert jusqu’au 8 novembre):

PAW 2023 – AI and Audio Programming Languages – Marie Curie Library, INSA Lyon (France) Dec. 2, 2023

The Programmable Audio Workshop (PAW) is a yearly one day FREE event gathering members of the programmable audio community around scientific talks and hands-on workshops. The 2023 edition of PAW is hosted by the INRIA/INSA/GRAME-CNCM Emeraude Team at the Marie Curie Library of INSA Lyon (France) on December 2nd, 2023. The theme of this year’s PAW is “Artificial Intelligence and Audio Programming Languages” with a strong focus on computer music languages (i.e., Faust, ChucK, and PureData). The main aim of PAW-23 is to give an overview of the various ways artificial intelligence is used and approached in the context of Domain Specific Languages (DSL) for real-time audio Digital Signal Processing (DSP).

More information and registration here

PhD Defence: “Navigation Among Movable Obstacles (NAMO) Extended to Social and Multi-Robot Constraints”, Benoit Renault, Amphi Chappe/Lamarr Building, 19th of December 2023 at 2 PM

The defense will take place on Tuesday 19th December at 2 PM in the Heidi Lamarr building (Amphi Chappe), Insa-Lyon, Villeurbanne.


Navigation Among Movable Obstacles (NAMO) Extended to Social and Multi-Robot Constraints


As robots become ever more commonplace in human environments, taking care of ever more tasks such as cleaning, security or food service, their current limitations only become more apparent. One such limitation is of their navigation capability in the presence of obstacles: they always avoid them, and freeze in place when avoidance is impossible.

This is what brought about the creation of Navigation Among Movable Obstacles (NAMO) algorithms, expected to allow robots to manipulate obstacles as to facilitate their own movement. However, these algorithms were designed under the hypothesis of a single robot per environment, biasing NAMO algorithms into only optimizing the single robot’s displacement cost – without any consideration for humans or other robots. While it is desirable to endow robots with the human capability of moving obstacles, they must however do so while respecting social norms and rules of humans.

We have thus extended the NAMO problem as to take into account these new social and multi-robots aspects. By relying on the concept of affordance spaces, we have developed a social occupation cost model allowing the evaluation of the impact of moved objects on the environment’s navigability. We implemented (and improved) reference NAMO algorithms, in our open source simulation tool, and modified them so that they may plan compromises between robot displacement cost and social occupation cost of moved obstacles – resulting in improved navigability. We also developed an implicit coordination strategy allowing the concurrent execution of these same algorithms by multiple robots as is, without any explicit communication requirements, while preserving the no-collision guarantee; verifying the relevance of our social occupation cost model in the actual presence of other robots. As such, this work constitutes the first steps towards a Social and Multi-Robot NAMO.


    • Philippe Mathieu , Professeur des Universités, Université de Lille, CRISTAL, Rapporteur
    • Fabien Michel, Maître de Conférences HDR, Université Montpellier 2, LIRMM, Rapporteur
    • Julie Dugdale, Professeur des Universités, Université de Grenoble, LIG, Examinatrice
    • Rachid Alami, Directeur de Recherche CNRS émérite, LAAS, Toulouse, Examinateur
    • Olivier Simonin, Professeur des Universités, INSA-Lyon, CITI, Directeur de thèse
    • Jacques Saraydaryan, Enseignant Chercheur, CPE Lyon, CITI, Co-encadrant

CITI seminar – Rémi Bardenet (CNRS) – 14/11 at 12:15

Speaker: Rémi Bardenet (CNRS) is a recipient of a 2021 CNRS bronze medal and PI of the ERC Starting Grant Blackjack (

Date: 14/11/2023

Time: 12h15

Place: Amphi Chappe/Lamarr, 6 avenue des arts, La Doua Campus

Title: Monte Carlo integration with repulsive point processes

Abstract: Joint work with Adrien Hardy, Ayoub Belhadji, Pierre Chainais, Diala Hawat, and Raphaël Lachièze-Rey.
Monte Carlo integration is the workhorse of Bayesian inference, but the mean square error of Monte Carlo estimators decreases slowly, typically as 1/N, where N is the number of integrand evaluations. This becomes a bottleneck in Bayesian applications where evaluating the integrand can take tens of seconds, like in the life sciences, where evaluating the likelihood often requires solving a large system of differential equations. I will present recent results on variance reduction and fast Monte Carlo rates using interacting particle systems. The underlying idea is that to integrate a function with a handful of evaluations, one should evaluate the function at well-spread (random) locations, where “well-spread” means “so that one can benefit from the smoothness of the target function”.