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Offers : 107

VHF voltage regulated converter incorporating innovative passive components

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Start date : 01/09/2022

offer n° SL-DRT-22-0658

The aim of the thesis is to develop a very high frequency voltage regulated converter (> 10 MHz) and exploiting innovative passive components. The increase in frequency allows the use of smaller passive components in value, size and weight. Indeed, the higher the frequency is, the lower the energy is stored and exchanged per cycle, the lower the volume of the inductor and / or capacity is and the higher the power density of the converter is. Moreover, a high switching frequency allows a faster converter response to operating condition changes (shorter response time).

However, when the converters operate at more than 10MHz, commonly used structures, even conventional resonant structures, are no longer suitable even via Zero Voltage Switching (ZVS). This is why a new inverter topology, breaking with half or full bridge topologies is being considered.

The objective of the thesis is to make VHF structures usable for common purposes by making the converter completely controllable: automatic frequency tracking, ZVS and output voltage regulation at the desired value. In addition, we aim to reduce, or even eliminate, the remaining inductances to gain compactness and EMC. We will also explore galvanic insulation aspects.

  • Keywords : Défis technologiques, Sciences pour l'ingénieur, Efficacité énergétique pour bâtiments intelligents, mobilité électrique et procédés industriels, Electronique et microélectronique - Optoélectronique, DSYS, Leti
  • Laboratory : DSYS / Leti
  • CEA code : SL-DRT-22-0658
  • Contact : sebastien.carcouet@cea.fr

Design of new heptazine-based catalysts for applications in the carbon circular economy

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Start date : 01/10/2022

offer n° SL-DRF-22-0267

The aim of this project is the conception of new catalysts for energy applications (CO2 reduction in methanol or formic acid, H2 formation etc…). Those catalysts will be based on graphitic carbon nitride (g-C3N4) derivatives in association with transition metals from first row. Our approach will include a molecular catalysis strategy using heptazine-based ligands and a heterogeneous catalysis strategy based on g-C3N4 functionalization. A systematic study of structure/activity relationships will allow the development of efficient and selective catalysts. To that end, classical characterization methods (Electrochemistry, EPR, NMR, UV-vis, GC-MS, DRX…) but also coupled methods (UV-vis/Electrochemistry, EPR/UV-vis, EPR/Electrochemistry) will be used.

  • Keywords : Défis technologiques, Physique de l'état condensé, chimie et nanosciences, Chimie, Energie verte et/ou décarbonnée dont bioprocédés et valorisation des déchets, IRIG, SyMMES
  • Laboratory : IRIG / SyMMES
  • CEA code : SL-DRF-22-0267
  • Contact : julie.andrez@cea.fr

Cooperative and heterogeneous multi-agent learning for 6G network orchestration

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Start date : 01/09/2022

offer n° SL-DRT-22-0250

In beyond 5G/6G networks , it is imperative to easily deploy and manage a private/ad-hoc network of mobile users such as a fleet of vehicles or drones. The objective of this thesis is to define strategies and associated protocols (control and resource allocation) to self-organize “mesh” networks of mobile users.

The research questions are: (i) How to manage a cooperative multi-agent system for the orchestration and self-organization of a 6G network? (ii) How to orchestrate a distributed multi-objective network? (iii) Are the multi-agent approach and network reconfiguration compatible with the dynamics of the environment?

While existing studies focus on problems aiming at optimizing a single objective function with homogeneous agents, we are interested in local/distributed multi-agent cooperative learning between heterogeneous users/moving agents (with different optimization functions).

The first step of this thesis will be to optimize heterogeneous multi-objective functions for a 6G network with a central orchestrator. The second step of this thesis will concern cooperative heterogeneous multi-agent systems and interactions between agents (concurrent learning, team learning, …) to jointly solve tasks and maximize utility. The last step of this thesis will concern a Hybrid approach (Centralized and Distributed)

  • Keywords : Défis technologiques, Data intelligence dont Intelligence Artificielle, Réseaux de communication, internet des objets, radiofréquences et antennes, DSYS, Leti
  • Laboratory : DSYS / Leti
  • CEA code : SL-DRT-22-0250
  • Contact : mickael.maman@cea.fr

Sensor Networks and Digital Twins for Mechatronic Systems Co-design

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Start date : 01/09/2022

offer n° SL-DRT-22-0201

As part of the development of its R&D activities on sensor networks and digital twins, the Autonomy and Sensor Integration Laboratory (DSYS/SSCE/LAIC) of CEA-LETI in Grenoble, France, is offering a thesis on “Sensor Networks and Digital Twins for the Co-design of Mechatronic Systems”. The LAIC laboratory is specialized in the design and development of innovative electronic systems, addressing physical and electronic issues of sensor interfaces, sensor integration, low power and wired or wireless communications, for various types of applications including industry 4.0, aeronautics, medical devices, or sports.

The aim of the PhD thesis is to implement a sensor network combined with multi-physics simulation tools and Artificial Intelligence-based analysis tools to develop Digital Twins. One application could be smart orthoses and prostheses for the medicine of the future, to detect premature ageing of the devices, to characterize usefulness and comfort for users and so supervise the patient rehabilitation and post-rehabilitation phases. The digital twin will be a virtual replica of the real system in operation. It will process, in real time, information from both the network of sensors deployed on the system (stresses/strain, IMU, etc.) and from finite element simulation models. It will be used to evaluate the operating state of the system, and in particular its ageing state, but also to predict its future behavior. These developments will subsequently allow the optimization of the operation, lifespan and environmental impact of mechatronic systems (predictive maintenance, eco-design).

  • Keywords : Défis technologiques, Sciences pour l'ingénieur, Instrumentation, Usine du futur dont robotique et contrôle non destructif, DSYS, Leti
  • Laboratory : DSYS / Leti
  • CEA code : SL-DRT-22-0201
  • Contact : elise.saoutieff@cea.fr

embedded elapsed-time attestation

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Start date : 01/09/2022

offer n° SL-DRT-22-0158

The security objectives of connected objects are usually Confidentiality, Integrity and Authentication (CIA). However, guaranteeing these objectives does not prevent changing the order of events or the elapsed time between two events. To meet these new security needs and ensure the security of an history of data or transactions, connected objects must be able to provide proof of the time interval separating two events, or two blocks of structured data, within an asynchronous communication system. This thesis topic proposes to explore possible solutions allowing a constrained device or IoT to prove the elapsed time based on secure hardware components such as TEE (Trusted Execution Environment), SE (Secure Element) and TPM (Trusted Platform Module).

  • Keywords : Défis technologiques, Cybersécurité: hardware et software, Réseaux de communication, internet des objets, radiofréquences et antennes, DSYS, Leti
  • Laboratory : DSYS / Leti
  • CEA code : SL-DRT-22-0158
  • Contact : christine.hennebert@cea.fr
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