Talks


1. Corentin Briat
Cybergenetics: Control theory in living cells (video) (slides)
ACCESS Alumni Day 2016, KTH, Stockholm, Sweden, May 2016


2. Corentin Briat
Analysis and control of stochastic reaction networks - Applications to biology (slides)
Séminaire d'Automatique du Plateau de Saclay, Supélec, France, November 2015


3. Corentin Briat
Analysis and Control of LPV Systems using Hybrid Systems Methods (slides)
IST Seminar, Stuttgart, Germany, June 2015


4. Corentin Briat
The conservation of information and the congestion control modeling problem (slides)
Seminar at the Ulf Jönsson Memorial Conference, invited by Anders Forsgren, KTH, Stockholm, Sweden, August 2012
Abstract
In communication networks, such as Internet, the congestion phenomenon is responsible for a reduction in network efficiency by inducing large communication delays and data loss. Modeling congestion to fully understand the phenomenon and deriving new congestion control protocols is then of great interest. Attacking the congestion problem from the systems and control theory viewpoint is not new. However, recent advances have made the models very accurate and flexible. In this talk, a complete model for congestion will be developed from a unique fundamental principle: the conservation of information; and is the fruit of my 2-year collaboration with Ulf Jönsson (but not only) when I was postdoc at KTH.

Models for transmission channels, queues and users are directly obtained from this principle. The corresponding network model hence consists of building blocks along with simple interconnection rules, as in electrical circuits (metamodel). The important properties of modularity and scalability are achieved for this model, emphasizing then the suitability of the paradigm. Comparison with NS-2 simulations and experimental results confirm the validity of the model on the considered topologies.

As a byproduct, it is also shown that previous models from the literature may be viewed as approximations of the proposed model, or shown to be exact whenever conditions on the network topology are met. Finally, linearization of the building blocks offers an easy way for locally representing any network topology, locally understanding the behavior of blocks, and deriving local stability results in a very generic way.


5. Corentin Briat
A conservation-law-based modular fluid-flow model for congestion in communication networks (slides)
Internal ACCESS Talk, KTH, Stockholm, Sweden, September 2011


6. Corentin Briat
Robust Control and Observation of LPV Time-Delay Systems (slides)
Ph.D. Defense Slides, Grenoble INP, France, 2008
Abstract
The slides provide a brief introduction on LPV and Time-Delay Systems. Some Lyapunov-Krasovskii results are then explained and studied. The origin of conservatism is illustrated and a method to reduce it is introduced. From the new stability results, stabilization conditions are derived using specific relaxations. Controllers with and without memory are synthesized and new types of controllers, called 'delay-robust controllers' are designed. These controllers contain a delayed term but the involved delay is different from the system one. Finally a discussion on 'delay-scheduled controllers' is provided, these controllers embed an information on the delay without any necessity of storing past values of the state. Finally some concluding remarks are given with future works.