PHD defense Sami Assenine

The defense will take place on February 26, 2026

Title
Reinforcement Learning for Mobility Optimization in Wireless Sensor Networks: Application to Pollution Monitoring Using Drone Fleets

Abstract
Atmospheric pollution remains a major environmental and public health challenge, affecting both large urban areas and industrial zones. While chronic pollution results from persistent long-term emissions, accidental pollution—caused by sudden events such as chemical leaks or explosions—requires precise monitoring and rapid intervention to mitigate its impacts. Traditional methods, including fixed monitoring stations and satellite observations, provide high-quality measurements for continuous and large-scale pollution monitoring. However, their limited spatial and temporal resolution makes them insufficient for detecting and tracking accidental pollution events, which evolve rapidly in both space and time.

To overcome these limitations, research has increasingly focused on the use of sensors embedded in mobile robotic platforms, notably Unmanned Aerial Vehicles (UAVs). These systems offer unprecedented flexibility and active sampling capabilities, enabling the collection of high-resolution spatio-temporal data in areas that are inaccessible or pose high risks to human operators. Advances in sensors and robotics, combined with recent developments in artificial intelligence—particularly Deep Reinforcement Learning (DRL)—have significantly transformed autonomous UAV control. By integrating path planning and intelligent decision-making, these approaches enable adaptive, multi-agent monitoring, simultaneously optimizing coverage, responsiveness, and operational robustness.

This convergence of low-cost sensing, robotics, and DRL motivated the research in this thesis, which explores this synergy to design autonomous systems for real-time mapping of dynamic phenomena, such as accidental pollution plumes. The contributions lie at the intersection of spatio-temporal modeling and multi-agent planning, aiming to optimize mapping quality as well as the deployment and redeployment of mobile agents. They are organized around two main axes: (1) a DRL approach coupled with a probabilistic Gaussian Process model for active mapping, where a fleet of UAVs learns to explore the most informative areas based on uncertainty-reduction rewards and incorporates connectivity constraints to ensure reliable inter-UAV communications; and (2) a DRL approach combined with data assimilation, designed to improve both the accuracy and speed of mapping while accounting for communication constraints and the dynamics of the observed phenomenon.

This thesis introduces a new modular framework that combines the spatio-temporal modeling of dynamic phenomena with real-time anticipatory path planning for cooperative UAVs. By jointly optimizing informativeness and communication through DRL, our approach provides a monitoring strategy that is both robust and generalizable.

Jury
– M. Marcelo DIAS DE AMORIM, Directeur de Recherche – CNRS – Rapporteur
– M. André-Luc BEYLOT, Professeur des Universités – Toulouse INP / ENSEEIHT – Rapporteur
– Mme. Isabelle GUERIN-LASSOUS, Professeure des Universités – Université Claude Bernard Lyon 1 – Examinatrice
– Mme. Christelle CAILLOUET, Maîtresse de Conférences (HDR) – Université Côte d’Azur – Examinatrice
– M. Grégoire DANOY, Chercheur Scientifique (HDR) – Université de Luxembourg – Examinateur
– M. Walid BECHKIT, Maître de Conférences (HDR) – INSA-LYON – Directeur de thèse
– M. Hervé RIVANO, Professeur des Universités – INSA-LYON – Co-directeur de thèse


Citi Seminar : Nicolas Papernot 15th december 10:00 AM

Speaker
Nicolas Papernot
https://www.papernot.fr/

Title
Learning from unlearning: how to audit ML systems?

When / Where 
Monday, December 15th at 10.
Bibliothèque Marie Curie, 31 avenue Jean Capelle 69621 Villeurbanne.
Salle Créativité 202/203

Abstract :
The talk first illustrates the challenges of having end users trust that machine learning algorithms were deployed responsibly, i.e., in a trustworthy way, through a deep dive on the problem of unlearning. The need for machine unlearning, i.e., obtaining a model one would get without training on a subset of data, arises from privacy legislation and more recently as a potential solution to data poisoning or copyright claims. As we present different approaches to unlearning, it becomes clear that they fail to answer our motivating question: how can end users verify that unlearning was successful? Taking a step back, we draw lessons for the broader area of trustworthy machine learning and present ongoing research that lay the foundations for companies, regulators, and countries to be able to verify meaningful properties at the scale that is required for stable governance of AI algorithms, both nationally and internationally.


CITI seminar Marc-Olivier Killijian : Monday, December 1st

Speaker
Marc-Olivier Killijian
https://kirija.github.io/

Title
les avancées du chiffrement homomorphe appliqué au machine learning

When / Where 
Monday, December 1st at 10.
Bibliothèque Marie Curie, 31 avenue Jean Capelle 69621 Villeurbanne.
Salle Créativité 202/203

Abstract :
Au cours des dernières années, la communauté du chiffrement homomorphe a franchi un cap décisif : le développement du functional bootstrapping dans les cryptosystèmes de type TFHE a transformé le paysage de la cryptographie appliquée au machine learning. En permettant d’évaluer efficacement des fonctions non linéaires
— longtemps considérées comme l’un des goulots d’étranglement fondamentaux du calcul chiffré — ces avancées offrent aujourd’hui la possibilité de transposer, presque sans compromis, des primitives d’apprentissage automatique dans un cadre entièrement chiffré.

Dans ce séminaire, il dressera un panorama de ces progrès et illustrerai, à travers trois contributions récentes, comment ces nouvelles briques cryptographiques ouvrent la voie à une véritable chaîne complète de machine learning sécurisé :
– Inférence chiffrée grâce à PROBONITE (WHAC’22), une des première méthode non-interactive permettant la traversée d’arbres de décision sous chiffrement en exploitant les opérations de comparaison dérivées du bootstrapping programmable.
– Apprentissage chiffré, avec BlindSort et Private k-NN (PETS’25), qui montrent comment exploiter les LUT homomorphes et les opérations inconscientes pour trier, agréger ou classer des données sensibles sans jamais les déchiffrer.
– Dés-apprentissage chiffré, présenté pour la première fois dans notre travail en cours, qui démontre qu’il est désormais possible de supporter de l’exact unlearning d’arbres de décision sous TFHE, de manière inconsciente, c’est-à-dire en rendant indiscernables les requêtes de formation, d’inférence et de dés-apprentissage.

Ces trois résultats illustrent une vision unifiée : l’utilisation de primitives comme le programmable bootstrapping, les LUT chiffrées ou les opérations d’accès aveugle (blind access) permet de dépasser la simple inférence privée, longtemps considérée comme l’horizon du FHE, pour aller vers des modèles réellement dynamiques, adaptatifs et conformes aux exigences modernes de protection de la vie privée — incluant notamment le droit à l’effacement.

Il conclura en discutant les perspectives offertes par ces nouveaux paradigmes, leurs défis pratiques et les questions ouvertes pour le déploiement de systèmes d’apprentissage machine complètement chiffrés, sûrs et auditables.


PhD defense Orégane Desrentes : “Hardware Arithmetic Acceleration for Machine Learning and Scientific Computing”

The defense will take place on wednesday 17th of september.

Title
Hardware Arithmetic Acceleration for Machine Learning and Scientic Computing.

Abstract
In a data-driven world, machine learning and scientific computing have become increasingly important, justifying dedicated hardware accelerators. This thesis explores the design and implementation of arithmetic units for such accelerators in Kalray’s Massively Parallel Processor Array.

Machine learning requires matrix multiplications that operate on very small number formats. In this context, this thesis studies the implementation of mixed-precision dot-product-and-add for various 8-bit and 16-bit formats (FP8, INT8, Posit8, FP16, BF16), using variants of a classic state-of-the-art technique, the long accumulator. It also introduces techniques to combine various input formats. Radically different methods are studied to scale to the larger range of 32-bit and 64-bit formats common in scientific computing.

This thesis also studies the evaluation of some elementary functions. An operator for exponential function (crucial for softmax computations) extends a state-of-the-art architecture to accept multiple input formats. The inverse square root function (used for layer normalisation) is accelerated by combining state-of-the-art techniques for range reduction, correctly rounded multipartite tables, and software iterative refinement techniques.

 

 


PhD Defense Sekinat Yahya : “A study of energy consumption challenges in extended reality services over cellular networks”

Date: 24/07/2025
Time: 10 am
Room: Amphitheatre Claude Chappe
Venue: Batiment Hedy Lamarr

Title
A study of energy consumption challenges in extended reality services over cellular networks

Abstract
Extended reality (XR) services are characterised by their heavy computational requirements throughout their life cycle. XR comprises multiple traffic modes consisting of 3D video and audio, haptics, sensor and pose information. Systems-related challenges relating to the creation, encoding, transmission, rendering and presentation of the application data from this class of services have increasingly become key areas of research inquiry from both a computational and energy viewpoint. Recently, new provisions have been made across different relevant standards to improve the capacity of these applications on mobile cellular networks. Our research investigates the energy-related challenges at both the RAN and UE levels.  We conduct our evaluations using system-level simulations (SLS) that adhere to the parameter specifications established by standardisation bodies.
We begin with a RAN-level energy reduction plus XR application enhancement strategy. With the cell switch off (CSO) technique proposed for BS deployment energy efficiency at low load, we evaluate the impact of an XR-capacity improvement criterion on the energy savings obtainable. Our analysis covers a European urban city using data from a European operator and system-level simulations according to the standard network operations.
In XR, UE energy-saving schemes are especially important since current delivery devices are still in early commercial development, making battery-saving techniques crucial. In this thesis, we use the Rel-18 improvements on the discontinuous reception (DRX) UE energy saving mechanism through state-of-the-art prediction algorithms to propose a traffic prediction-based non-integer DRX mechanism. We achieved significant energy savings without impeding the XR quality of service requirements.
Lastly, towards enhancing the capacity of XR on cellular networks in energy-saving mode, we propose a DRX plus QoE-aware scheduler (DQAS). Using SLS according to 3GPP specifications on XR QoE requirements, traffic model, and dense urban deployment scenarios, and following real traces from XR applications, we first evaluate a QoE-aware scheduler (QAS) for XR services. We introduced DRX awareness into QAS, jointly improving XR QoE and energy consumption. We analysed our results to identify the parameter window in which both metrics can be improved towards achieving the goal of XR capacity improvement on cellular networks.

Jury
– Riadh Dhaou, Professor des Universites (University of Toulouse), Rapporteur
– Thi-Mai-Trang Nguyen, Professeur des Universités (Sorbonne Paris Nord University), Rapporteure
– Nadjib Achir, Maître de Conférences HDR(Sorbonne Paris Nord University), Examinateur
– Herve Rivano, Professeur des Universités (INSA Lyon), Examinateur
– Razvan Stanica, Maître de Conférences HDR (INSA Lyon), Directeur de thèse


Research Awards Ceremony

Congratulations to the CITI lab award recipients !

Mrs Oana IOVA – associate professor
GDR RSD 2024 Award for Best Junior woman researcher

Professor Florent DE DINECHIN
Best paper of the Last 15 Years – ACM SIGDA
Publication of a reference book

Walid BECHKIT and Antoine BOUTET – associate professors
2024 graduate HDR

Jan AALMOES ; Aurélien DELAGE ; Romain FONTAINE : Patrik FORTIER ; Gwendoline HOCHET DEREVIANCKINE ; Alix JEANNEROT ; Thomas LEBRUN ; Lucas MAGNANA ; Guillaume MARTHE ; Shashwat MISHRA ; Camille MORIOT ; Samuel PELISSIER ; Xiao PEND ; Mateus PONTES MOTA ; Maxime POPOFF
2024 PhD graduate

 


HDR defense Florin HUTU : Design of radio front-end architectures to meet low energy consumption or resource sharing objectives

When
Monday 30 June at 10:00 am

Where
AE1 amphitheater, Gustave Ferrié building, 8 rue de la Physique, F-69621 Villeurbanne

https://insa-lyon-fr.zoom.us/j/95728542338

Title
Design of radio front-end architectures to meet low energy consumption or resource sharing objectives

Abstract
The contributions presented are structured around four main research areas :
i) the energy consumption of connected devices, with the proposal of asynchronous wake-up radio solutions;
ii) the harvesting of ambient electromagnetic energy;
iii) the design of UHF RFID tags that are robust to elongation or integrate sensing capabilities (humidity/temperature), and on the other hand, studies on the tag-to-tag communication concept;
iv) the reduction of the dynamic range of input signals of analog-to-digital converters, as well as the joint implementation of spatial modulation and a full-duplex mode.
Depending on the addressed topic, the studies presented in this manuscript include theoretical, simulation, experimental, and real-world testing, with particular attention to the non-idealities of the radio front-end building
blocks and their impact on performance.
Based on the acquired expertise and the collaborations conducted at the national and international levels in various contexts, the final section identifies several new research directions that are being considered.

Jury
Prof. Daniela DRAGOMIRESCU INSA Toulouse ; reviewer
Prof. Ioannis KRIKIDIS Université de Chypre ; reviewer
Prof. Smail TEDJINI Université Grenoble-Alpes, Grenoble INP; reviewer
Prof. Yvan DUROC Université Claude Bernard Lyon 1 ; examiner
Prof. Bruno ALLARD INSA Lyon ; examiner
Prof. Guillaume VILLEMAUD INSA Lyon ; examiner


HDR defense Carlos Barrios : MultiScale-HPC Hybrid Architectures: Developing Computing Continuum Towards Sustainable Advanced Computing

When
The defense will take place on june 6th at 9 AM.

Where
INSA Lyon Campus,  CITI Laboratory, Amphi Chappe,  Building Hedy Lamarr, 6 Avenue des Arts 69621 Villeurbanne, France

https://insa-lyon-fr.zoom.us/j/91634868780?pwd=i5znUHEaIiuahaoIkrkL0g5DU9fEaD.1

Title
MultiScale-HPC Hybrid Architectures: Developing Computing Continuum Towards Sustainable Advanced Computing.

Jury
Prof. Eddy CARON (UCBL, Lyon, France)
Prof. Ewa DEELMAN (USC, Los Angeles, United States of America)
Prof. Michaël KRAJECKI (URCA, Reims, France)
Prof. Genoveva VARGAS SOLAR (CNRS, Lyon, France)
Prof. Bernd MOHR (JSU, Jülich, Germany)
Prof. Frédéric DESPREZ (INRIA, Grenoble, France)
Prof. Frédéric LE MOUËL (INSA, Lyon, France)