Showing papers by "Georges Bastin published in 2013"
Book•
22 Oct 2013
TL;DR: The general dynamical model of bioreactors was extended to include extended Luenberger and Kalman observers and asymptotic observers for state estimation when the reaction rates are unknown, and a general solution to the linearizing control problem for a class of CST bioreacts was found.
Abstract: Chapter 1. Dynamical Models of Bioreactors. Introduction. The basic dynamics of microbial growth in stirred tank reactors. Extensions to the basic dynamics. Models of the specific growth rate. The reaction scheme of a biotechnological process. General dynamical model of bioreactors. Examples of state space models. A basic structural property of the general dynamical model. Reduction of the general dynamical model. Stability analysis. Extending the general dynamical model. References and bibliography. Chapter 2. Kinetic Modelling, Estimation and Control in Bioreactors: An Overview. Introduction. Difficulties in modelling the reactor kinetics. Minimal modelling of reaction kinetics. Software sensors for bioreactors. Adaptive control of bioreactors. Conclusions and perspectives. References and bibliography. Chapter 3. State and Parameter Estimation with Known Yield coefficients. Introduction. On state observation in bioreactors. Extended Luenberger and Kalman observers. Asymptotic observers for state estimation when the reaction rates are unknown. On-line estimation of reaction rates. References and bibliography. Chapter 4. State and Parameter Estimation with unknown yield coefficients. Introduction. On-line estimation of the specific reaction rates. Joint estimation of yield coefficients and specific reaction rates. Adaptive observers. Estimation of yield coefficients. Other parameter estimation issues in bioreactors. References and bibliography. Chapter 5. Adaptive Control of Bioreactors. Introduction. Principle of linearizing control and remarks on closed loop stability. Singular perturbation design of linearizing controllers. Adaptive linearizing control (known yield coefficients). A general solution to the linearizing control problem for a class of CST bioreactors. Adaptive linearizing control (unknown yield coefficients). Practical aspects of implementation. Case study: Adaptive linearizing control of fed-batch reactors. Case study: Adaptive control of the gaseous production rate of a synthesis product. References and bibliography. Appendix 1. Models of the Specific Growth Rate. Appendix 2. Elements of Stability Theory. Appendix 3. Persistence of excitation. Convergence of Adaptive Estimators. Nomenclature. Index.
1,371 citations
TL;DR: In this article, the authors considered the problem of boundary stabilization for a quasilinear first-order hyperbolic PDE with actuation on only one end of the domain.
Abstract: In this work, we consider the problem of boundary stabilization for a quasilinear $2\times2$ system of first-order hyperbolic PDEs. We design a new full-state feedback control law, with actuation on only one end of the domain, which achieves $H^2$ exponential stability of the closed-loop system. Our proof uses a backstepping transformation to find new variables for which a strict Lyapunov function can be constructed. The kernels of the transformation are found to verify a Goursat-type $4\times4$ system of first-order hyperbolic PDEs, whose well-posedness is shown using the method of characteristics and successive approximations. Once the kernels are computed, the stabilizing feedback law can be explicitly constructed from them.
231 citations
TL;DR: A methodology proposed in Jungers et al. (2011) is used to compute a decomposition of admissible flux vectors in a minimal number of elementary flux modes without explicitly enumerating all of them, and a set of macroscopic bioreactions linking the extracellular measured species is obtained at a very low computational expense.
51 citations
TL;DR: In this paper, a class of density-flow networks, described by hyperbolic conservation laws, which can be monitored and controlled at the junctions, are considered and the problem of feedback stabilization and disturbance rejection under PI boundary control is addressed.
14 citations
Posted Content•
TL;DR: In this article, a simple mathematical model for the transition to a sustainable economy is presented to explore the long-run evolution of an economy that achieves environment protection, full recycling of material resources and limitation of greenhouse gas emissions.
Abstract: We present a simple mathematical model for the transition to a sustainable economy in order to explore the long-run evolution of an economy that achieves environment protection, full recycling of material resources and limitation of greenhouse gas emissions The main concern is to investigate how balanced economic paths are modified under public policies for transition to sustainability We consider a world economy with two subregions that are endowed with greenhouse gas emissions and ecological footprint of OECD and non-OECD countries respectively Then, for the OECD subregion, three different options are investigated : a green growth option that focuses on accelerating the green technological change, a low growth option that focuses on shifting the structure of the economy towards low carbon and low capital intensive activities and a combined green-low growth option that focuses on the limitation of material resources and the abatement of the ecological footprint
3 citations
01 Jan 2013
TL;DR: In this article, the authors present a simple mathematical model for the transition to a sustainable economy in order to explore the long-run evolution of an economy that achieves environment protection, full recycling of material resources and limitation of greenhouse gas emissions.
Abstract: We present a simple mathematical model for the transition to a sustainable economy in order to explore the long-run evolution of an economy that achieves environment protection, full recycling of material resources and limitation of greenhouse gas emissions. The main concern is to investigate how balanced economic paths are modified under public policies for transition to sustainability. We consider a world economy with two subregions that are endowed with greenhouse gas emissions and ecological footprint of OECD and non-OECD countries respectively. Then, for the OECD subregion, three different options are investigated : a green growth option that focuses on accelerating the green technological change, a low growth option that focuses on shifting the structure of the economy towards low carbon and low capital intensive activities and a combined green-low growth option that focuses on the limitation of material resources and the abatement of the ecological footprint.
01 Jan 2013
TL;DR: A dynamic mathematical model of the complex network regulating competence of the luxAB reporter genes is developed, based on ordinary differential equations, which will allow to test different hypothesis and to orient future experiments consequently.
Abstract: Experimental data is generated by analyzing the specific luciferase activity in different reporter strains. The insertion of an ectopic copy of the promoter of the key early genes (comR, comS, comX) upstream of the luxAB reporter genes allows us to monitor the specific promoter activities throughout the growth. This time-series is our proxy for the production rates of the corresponding genes. The luciferase activities are also measured in mutant strains, deleted for each early gene. Another essential information for the model is the growth kinetics, which is estimated by measuring the optical cell density. The aim of this study is to develop a dynamic mathematical model of the complex network regulating competence. Based on ordinary differential equations, the model parameters are set according to prior knowledge and experimental data. In silico simulations will allow to test different hypothesis and to orient future experiments consequently.
07 Mar 2013