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Alain Rapaport

Bio: Alain Rapaport is an academic researcher from SupAgro. The author has contributed to research in topics: Optimal control & Chemostat. The author has an hindex of 27, co-authored 230 publications receiving 3128 citations. Previous affiliations of Alain Rapaport include Arts et Métiers ParisTech & French Institute for Research in Computer Science and Automation.


Papers
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TL;DR: In this paper, the authors present a technique for the dynamic estimation of bounds on unmeasured variables (or parameters) of an uncertain dynamical system, which relies on interval observers: from (possibly time varying) intervals on the uncertainty and measurements, they compute guaranteed intervals for the variables.

634 citations

Journal ArticleDOI
TL;DR: Building plant/soil models to explore how PE and microbial diversity influence soil/plant interactions and ecosystem C and nitrogen dynamics in response to global change suggests that the PE and functional role of microbial diversity may be incorporated in ecosystem models with a few additional parameters, improving accuracy of predictions.
Abstract: Integration of the priming effect (PE) in ecosystem models is crucial to better predict the consequences of global change on ecosystem carbon (C) dynamics and its feedbacks on climate. Over the last decade, many attempts have been made to model PE in soil and its underlying mechanisms. However, PE has not yet been incorporated into any ecosystem models. Here we build plant-soil models to explore how PE and microbial diversity influence soil-plant interactions and ecosystem C and nitrogen (N) dynamics in response to global change (elevated CO2 and increased atmospheric N deposition). Our results show that plant persistence, soil organic matter (SOM) accumulation and low N leaching in undisturbed ecosystems relies on a fine adjustment of microbial N mineralization to plant N uptake. This adjustment can be modeled in the SYMPHONY model by considering the destruction of SOM through PE and the interactions between two distinct microbial functional groups: SOM-decomposers and SOM-builders. After estimation of parameters, SYMPHONYprovided realistic predictions on forage production, soil C storage and N leaching for a permanent grassland. Consistent with recent observations, SYMPHONY predicted a CO2-induced modification of soil microbial communities leading to an intensification of SOM mineralization and a decrease in the soil C stock. SYMPHONY also indicated that atmospheric N deposition may stimulate SOM accumulation via changes in the structure and metabolic activities of microbial communities. Collectively, these results suggest that PE and the functional role of microbial diversity may be incorporated in current ecosystem models with a few additional parameters, improving accuracy of predictions.

111 citations

Journal ArticleDOI
TL;DR: It is shown in particular that when the process inputs are known, the static observation error on the unknown state is inversely proportional to one of the observer gains.
Abstract: This paper concentrates on the state observation in bioprocesses when there is uncertainty on the process parameters and/or the process inputs. An interval observer is designed on the basis of the cooperativity properties of the model for a standard stirred tank bioreactor model with a single microbial growth and a kinetic model depending on the substrate concentration. Further assumptions are the (lower and upper) boundedness of the specific growth rate and the inlet substrate concentration. Mathematical analysis of the stability and convergence of the interval observer is performed both in absence and in presence of uncertainty on the measurements. It is shown in particular that when the process inputs are known, the static observation error on the unknown state is inversely proportional to one of the observer gains. The performance of the interval observer are also illustrated through numerical simulation.

106 citations

Journal ArticleDOI
TL;DR: This paper presents the practical implementation of a new robust interval observer on a 1 m3 continuous fixed bed anaerobic reactor used for the treatment of industrial wine distillery wastewater to generate guaranteed intervals for the unmeasured variables from few on-line measurements.

105 citations

Journal ArticleDOI
TL;DR: For a class of dynamical systems, with uncertain non-linear terms considered as unknown inputs, the authors gave suffcient conditions for observability and showed that there does not exist any exact observer independent of the unknown inputs.
Abstract: For a class of dynamical systems, with uncertain non-linear terms considered as unknown inputs, we give suffcient conditions for observability. We show also that there does not exist any exact observer independent of the unknown inputs. Under the additional assumption that the uncertainty is bounded, we build practical observers whose error converges exponentially towards an arbitrarily small neighbourhood of the origin. Under the hypothesis that bounds are available for the uncertain terms, we build parallelotopic observers providing time-varying bounds for the state variables, even when the system is not observable for unknown inputs. These results are illustrated with a biological model of a structured population.

80 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal ArticleDOI
TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

14,171 citations

Journal ArticleDOI
06 Oct 2011-Nature
TL;DR: In this article, a new generation of experiments and soil carbon models were proposed to predict the SOM response to global warming, and they showed that molecular structure alone alone does not control SOM stability.
Abstract: Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily—and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have demonstrated that molecular structure alone does not control SOM stability: in fact, environmental and biological controls predominate. Here we propose ways to include this understanding in a new generation of experiments and soil carbon models, thereby improving predictions of the SOM response to global warming.

4,219 citations

Journal ArticleDOI
TL;DR: In this article, the authors extensively review the principles of anaerobic digestion, the process parameters and their interaction, the design methods, the biogas utilisation, the possible problems and potential pro-active cures, and the recent developments to reduce the impact of the problems.

2,616 citations

Book
01 Jan 1991
TL;DR: In this paper, the Third Edition of the Third edition of Linear Systems: Local Theory and Nonlinear Systems: Global Theory (LTLT) is presented, along with an extended version of the second edition.
Abstract: Series Preface * Preface to the Third Edition * 1 Linear Systems * 2 Nonlinear Systems: Local Theory * 3 Nonlinear Systems: Global Theory * 4 Nonlinear Systems: Bifurcation Theory * References * Index

1,977 citations