20th January 2015 AM

Automatique, Boulevard Dolez 31 - 7000 Mons


"Mathematical Models for Competition and Coexistence of Microbial - Species in a chemostat"

This thesis focuses on the mathematical analysis of models of several species in competition on a single resource in a chemostat. The objective is to model and show the coexistence of microbial species by different mechanisms to better realize biodiversity found in nature like in the bioreactors. We are interested mainly in three mechanisms of coexistence :

1. The inter-specific competition between populations of micro-organisms and intra-specific between individuals of the same species.

2. The flocculation where the species who wins the competition inhibits its growth by the formation of flocs, which allows the coexistence with the other species. In fact, these flocs consume less substrate than isolated bacteria since they have less access to the substrate, given that this access to the substrate is proportional to the outside surface of the floc.

3. The density-dependence, whose model can be built from the flocculation model, assuming that the dynamics of flocculation is faster than the growth dynamics of the species. In this density-dependent model, the growth rate depends not only on the density of substrate but also on the density of biomass, and the removal rate of biomass is not constant but depends also on the density of biomass. Finally, we studied a 3-step model of anaerobic digestion with enzymatic degradation of the substrate (organic matter) that can partly be under a solid form. The mathematical analysis shows that this model may exhibit the quadri-stability with washout of none, one or two species according to the initial condition. The mathematical study of the qualitative behavior of different models of the chemostat, allowed us to better understand the competition and the coexistence of microbial species.

7th November 2014 AM

Automatique, Boulevard Dolez 31 - 7000 Mons

Alejandro Vargas

"Basic statistical analysis and experiment design (part 1)"

The first part of this short course will focus on reviewing basic statistical analysis tools, which are often needed in the experimental sciences. We will review the concepts of random variables and their distributions, the central limit theorem, tests for normality, confidence intervals for statistical parameters and hypothesis testing, with an emphasis on t-tests, chi-squared tests and the one-way analysis of variance (ANOVA). Examples will be worked out with the open-source statistical software package R.

13th November 2014 AM

Automatique, Boulevard Dolez 31 - 7000 Mons

Alejandro Vargas

"Basic statistical analysis and experiment design (part 2)"

The second part of this short course will focus on expanding analysis of variance (ANOVA) techniques and presenting 2-level factorial experiment designs, including blocking and fractional designs. Other useful factorial experiment design techniques will be reviewed (e.g. central composite designs). Examples will again be worked out with the open-source statistical software package R.

15th May 2014

Automatique, Boulevard Dolez 31 - 7000 Mons

Jean-Sebastien Deschênes (University of Quebec at Rimouski)

"Extremum seeking control of micro-algal cultures"

5th December 2013

Automatique, Boulevard Dolez 31 - 7000 Mons

Lino Santos (University of Coimbra)

"An introduction to model predictive control"

1st July 2013 10AM

Automatique, Boulevard Dolez 31 - 7000 Mons

Andres Donoso-Bravo - INRIA-Chile. Chilean Informatics Research and Innovation Centre (CIRIC)

"Modeling the pretreatment effect in Anaerobic Digestion: Present and future perspectives"

25th March 2013 12:15

Amphithéâtre Marie Curie, UMONS (Campus plaine)

Jean-Christophe Poggiale - Pytheas Institute (OSU) - Aix-Marseille University

A seminar organized by the Institute of Biosciences (IBS):

"La modélisation en écologie marine : de l'individu à l'écosystème, quelle représentation adopter?"

La compréhension du fonctionnement et de la structure des écosystèmes marins et de leurs réponses à des perturbations (contamination, pêche, augmentation de la température, etc.) nécessite de nombreuses approches allant de l'observation en milieu naturel à la modélisation mathématiques, en passant par l'expérimentation en laboratoire. Les données du milieu naturel, de plus en plus nombreuses grâce au développement d'outils d'observation de plus en plus nombreux, reflètent des grandeurs caractéristiques d'un grand nombre de processus qui interagissent à différentes échelles spatiales et temporelles. Les données acquises en laboratoire permettent de s'affranchir de la complexité du milieu naturel et autorisent la description de la réponse des organismes vivants à la variation d'un nombre limité de facteurs en milieu contrôlé.

Quant à la modélisation mathématique, elle permet d'intégrer les processus qui semblent les plus pertinents pour une question posée et vise à comprendre par exemple les effets des interactions de ces processus sur la dynamique du système complet. Or, la complexité des modèles mathématiques utilisés pour la représentation des écosystèmes marins est devenue telle qu'une étude approfondie de leur propriété est devenue très difficile.

Par ailleurs, l'approche consiste généralement à intégrer dans ces modèles des formulations mathématiques obtenues à partir des données acquises en laboratoire. Nous discuterons dans cet exposé, à partir d'exemple précis, de la pertinence et des limites de cette approche. En nous fondant sur différents travaux, nous discuterons quelques perspectives permettant de construire des formulations à des échelles globales écosystémiques sur la base de connaissances locales, à l'échelle des individus, dans des conditions proches de l'échelle du laboratoire.

18th February 2013 15:30

Automatique, Boulevard Dolez 31 - 7000 Mons

Mathieu Claeys - Ph.D. student, LAAS-CNRS

"An introduction to the moment approach for optimal control"

This tutorial talk is devoted to the moment/sum-of-squares approach, which provides a general framework for global optimization of many problems, including optimal control.

In the first part of the talk, we will review the philosophy of the approach on the problem of global minimization of a polynomial function, for which the user-friendly GloptiPoly toolbox is readily available. The focus will therefore be on introducing the mathematical tools and the elegant transformations that are used behind the scene by the software: transformation of the original problem into a linear problem on measures, then manipulation of those measures by their moments to obtain tractable semi-definite relaxations.

The second part of the talk will show how to extend the approach for functional optimization problems such as optimal control. Measures arise quite naturally in this context, and the moment approach is therefore well suited to tackle those problems fruitfully. This will be shown on the two examples of bounded and impulsive control problems.

1st October 2012 11:00

Local 120, Bâtiment 4, Plaine de Nimy Sylvain

A seminar organized by the Institute of Biosciences (IBS):

Prof. Russel Stewart (Dept of Bioengineering, University of Utah)

"The underwater adhesives of caddisflies and sandcastle worms"

3rd October (10:30 - 13:00) and 4th October (10:30-13:00)

Service d'Automatique, Boulevard Dolez 31, 7000 Mons

Model Predictive Control: basic concepts and formulations

Prof. Lino Santos, University of Coimbra

Model predictive control (MPC) has received great attention since the report on its successful industrial applications in the end of the 70s. There is nowadays a rich literature on MPC technology, its formulations, algorithms, and properties, with examples of applications in various domains, from small to large scale systems. In these seminars we will focus on the application of MPC to chemical processes. First, the basic concepts and a linear formulation are presented. Then the extension to nonlinear formulations based on first principle models is discussed and illustrated with simulated and experimental process examples. Finally, a brief overview focusing on recent research works in the domain of nonlinear MPC will be given.

11th October 2012 15:30-16:30

Service d’Automatique, Boulevard Dolez 31, 7000 Mons

Improving a PHA production process using a simple process controller

Polyhydroxyalkanoates (PHAs) are biodegradable polymers that may accumulate as granules in many types of bacteria when fed appropriately with certain substrates such as high strength wastewater. They have gained attention recently because they can be harvested to be used as renewable biodegradable plastics. This work presents the use of process control techniques to enhance the production of PHA from organic wastewater in a two bioreactor laboratory scale system. Sludge from a conventional wastewater treatment plant is first enriched in a sequencing batch reactor (SBR) under aerobic dynamic feeding, while a second fed-batch reactor inoculated with the excess biomass from the SBR is used for PHA cultivation. The controller provides pulses of substrate periodically to this reactor, according to a continually updated simple dynamic mathematical model of the process. Experimental results show the advantages of the approach with respect to other strategies.

Alejandro Vargas (UNAM, Juriquilla, Mexico - in sabbatical stay at UMONS)

16th October 2012 15:30-16:30

Service d’Automatique, Boulevard Dolez 31, 7000 Mons

Bioreaction rate estimation using a super-twisting observer during toxic wastewater treatment.

In the control of certain reactive systems such as bioreactors it is useful to know the reaction rate on-line. However, sensors have not been developed for this purpose and thus it is of interest to build a software sensor or observer to estimate its value using the information provided by other measurements. In this work, a supaer-twisting observer is used to estimate the reaction rate in a fed-batch bioreactor used to treat toxic wastewater using only measurements of the dissolved oxygen concentration. The robustness of the designed observer with respect to some uncertainties is exploited to also consider the dynamics of the sensor. The observer is tested via numerical simulations and in closed loop with a controller that aims at keeping the bioreaction rate at its maximum for the most time during the reaction.  

Alejandro Vargas (UNAM, Juriquilla, Mexico - in sabbatical stay at UMONS)

24th October and Friday 26 October, 2012

Service d’Automatique, Boulevard Dolez 31, 7000 Mons

In the framework of the Graduate schools SOCN and GEPROC : Robust Control: A LMI Based Perspective (with Applications to Bioprocesses)

Prof. Daniel Coutinho, Federal University of Santa Catarina, Brazil

The course aims at providing an introduction to the robust control paradigm for stability and performance analysis, and control synthesis for dynamical systems based on the linear matrix inequality (LMI) framework. To this end, the course is organized in four modules which can be separately attended depending on background knowledge of the students on the theory of dynamical systems.

Link : A_Course_on_Robust_Control_with_Applications_to_Bioprocesses.doc