Дисертації з теми "Approche écosystémique – Modèles mathématiques"
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Dinaharison, Jean Bienvenue. "Conception d’une approche spatialisée à base d’agent pour coupler les modèles mathématiques et informatiques : application à la modélisation du processus écosystémique du sol." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS184.
Soil is a highly heterogeneous environment in which many processes interact to provide ecosystem services. Model coupling approaches propose to define such system by using a modular architecture in which various processes, represented by models, communicate to reproduce different aspects of a phenomenon such as soil functioning. In this thesis project, we develop such an approach for the purpose of modelling soil functioning. The challenges of such a scheme lie in solving representation problems of soil processes. These representation problems originate from the fact that models from various disciplines are reused to describe the processes. By representations problems, we mean model description which can be (individual or equation based), the temporal execution settings and data resolution. These coupling constraints are addressed by a number of approaches in the literature. All of them propose satisfactory solutions to these constraints in their respective application fields. In our approach, we use the agent paradigm to encapsulate the various soil processes. Then processes will communicate through the space by using resources inside it. The behaviour of the processes then depends on the availability of resources. A coordination problem can arise from this type of coupling, as processes may consume the resource simultaneously while the resource may not support this demand. To overcome that matter, we use an action-theoretic technique called Influence-Reaction to define strategies to manage this type of situation. We used algorithms suggested by the abbundant litterature to manage any processes temporality issues. This coupling approach was applied to a model of organic matter decomposition in which several processes (earthworms, microbes and roots) compete for soil ressources. The results suggest that the use of our approach is suitable for modelling soil functioning, but also gives more accurate indications of resource availability
Moullec, Fabien. "Impacts du changement global sur la biodiversité en mer Méditerranée : une approche par modélisation End-to-End." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG015/document.
Under the combined effects of overexploitation of marine resources and climate change the Mediterranean Sea is gradually becoming a hotspot of global change. Despite a large number of models developed locally or regionally in the Mediterranean Sea, no previous studies have addressed changes in species assemblages at the basin scale with an integrated ecosystem modelling from physics to predators and explicitly representing the multi-species, spatial, and trophic dimensions. This thesis work presents a threefold challenge: (i) implementing such a model of the species richness in the Mediterranean Sea based on life history traits and representing the entire life cycle of interacting species; (ii) projecting the consequences of physical and biogeochemical changes induced by climate change on the spatial distribution of species and on the structure and trophic functioning of the Mediterranean ecosystem; (iii) exploring fisheries management scenarios aiming at rebuilding some stocks of commercial interest in a climate change context. To address these challenges, an end-to-end model, OSMOSE-MED, based on the coupling of a high trophic level OSMOSE model with NEMOMED12 and ECO3M-S physical and biogeochemical models, has been developed. With 100 modelled species, representing nearly 95% of the catches made in the Mediterranean Sea, it is the first trophic model of this type to integrate such a large diversity of species, on such a large spatial scale (the Mediterranean Sea as a whole) and at fine resolution (20x20 km²). According to the greenhouse gas emissions scenario RCP8.5, projections made with the OSMOSE-MED model show an overall increase in biomass and catches of 22% and 7% respectively by the end of the century. However, these increases mask large geographical disparities. The eastern basin is characterized by an overall increase in biomass associated with exotic species. With regard to catches, the model projects increase in the eastern basin and a significant decrease in the western part. A change in the species composition of catches could appear during the 21st century with winner (e.g. anchovy) and loser (e.g. hake) species. Winner species would mainly belong to the small pelagics group, are thermophilic and/or exotic, of smaller sizes and of low trophic level while loser species are generally large-sized, some of them of great commercial interest, and could suffer from a spatial mismatch with potential prey subsequent to a contraction or shift of their geographic range. Fisheries management scenario projections highlight the benefits of greater selectivity or reduced fishing mortality for the recovery of certain stocks of commercial interest, particularly among organisms belonging to the demersal, benthic and large pelagic groups. A reduction in fishing mortality could also reverse the projected decline in biomass and total catches in the Western Mediterranean
Bieupoude, Guélaih Pascal. "Approche constructale pour l’optimisation de réseaux hydrauliques." Perpignan, 2011. http://www.theses.fr/2011PERP1279.
The optimization of water distribution network involves the three sensible following questions: water quality management, pumping energy and the investment cost. The geometry of the distribution network and the laws that distribute pipes diameters and pipes lengths influence strongly the effectiveness of such systems. In this thesis, an original approach relating quality to quantity and based on the geometric, multi-scale and multi-criteria optimization called constructal design was used to optimize these systems. It permitted to demonstrate that there are some optimal water network configurations that minimize the total head losses and by the same moment have better operating residence time. This is an added value as far as energy saving and optimal water quality management are concerned. A comparison with former methods enabled to reinforce the effectiveness of results developed in the present work
Oliveros, Ramos David Ricardo. "Modélisation "end-to-end" pour une approche écosystémique des pêches dans le Nord courant de Humboldt." Thesis, Montpellier 2, 2014. http://www.theses.fr/2014MON20220.
This work represents an original contribution to the methodology for ecosystem models' development as well as the first attempt of an end-to-end (E2E) model for the Northern Humboldt Current Ecosystem (NHCE). The main purpose of the developed model is to build a tool for ecosystem-based management and decision making, reason why the credibility of the model is essential, and this can be assessed through confrontation to data. Additionally, the NHCE exhibits a high climatic and oceanographic variability at several scales, the major source of interannual variability being the interruption of the upwelling seasonality by the El Nino Southern Oscillation, which has direct effects on larval survival and fish recruitment success. Fishing activity can also be highly variable, depending on the abundance and accessibility of the main fishery resources. This context brings the two main methodological questions addressed in this thesis, through the development of an end-to-end model coupling the high trophic level model OSMOSE to the hydrodynamics and biogeochemical model ROMS-PISCES: i) how to calibrate ecosystem models using time series data and ii) how to incorporate the impact of the interannual variability of the environment and fishing.First, this thesis highlights some issues related to the confrontation of complex ecosystem models to data and proposes a methodology for a sequential multi-phases calibration of ecosystem models. We propose two criteria to classify the parameters of a model: the model dependency and the time variability of the parameters. Then, these criteria along with the availability of approximate initial estimates are used as decision rules to determine which parameters need to be estimated, and their precedence order in the sequential calibration process. Additionally, a new Evolutionary Algorithm designed for the calibration of stochastic models (e.g Individual Based Model) and optimized for maximum likelihood estimation has been developed and applied to the calibration of the OSMOSE model to data time series.The environmental variability is explicit in the model: the ROMS-PISCES model forces the OSMOSE model and drives potential bottom-up effects up the foodweb through plankton and fish trophic interactions, as well as through changes in the spatial distribution of fish. The latter effect was taken into account using presence/absence species distribution models which are traditionally assessed through a confusion matrix and the statistical metrics associated to it. However, when considering the prediction of the habitat against time, the variability in the spatial distribution of the habitat can be summarized and validated using the emerging patterns from the shape of the spatial distributions. We modeled the potential habitat of the main species of the Humboldt Current Ecosystem using several sources of information (fisheries, scientific surveys and satellite monitoring of vessels) jointly with environmental data from remote sensing and in situ observations, from 1992 to 2008. The potential habitat was predicted over the study period with monthly resolution, and the model was validated using quantitative and qualitative information of the system using a pattern oriented approach.The final ROMS-PISCES-OSMOSE E2E ecosystem model for the NHCE was calibrated using our evolutionary algorithm and a likelihood approach to fit monthly time series data of landings, abundance indices and catch at length distributions from 1992 to 2008. To conclude, some applications of the model for fishery management are presented and their limitations and perspectives discussed
Luginbühl, Thibault. "Régularisation de surface 3D par une approche fondée sur un modèle." Paris 6, 2012. http://www.theses.fr/2012PA066032.
In this thesis we present a system to generate 3D photo-realistic avatars automatically using a laser scanner. First, we turn the point cloud provided by the scanner into a suitable representation, that is a closed mesh. Our approach is based on a generic model of the human body that is fitted to the data using computer graphics techniques for mesh edition. Then, we add texture information to the 3D geometry using pictures taken during the acquisition. This problem is solved by optimizing the choice of a camera for each triangle of the mesh and treating the continuity problem at the seams. Finally, we show direct application of our system relying on the common parameterization provided by the generic model: use of the avatars in a virtual try-on application, modifying the haircut of the reconstructed model and animation transfer
Jouini, Jamel. "Approche économétrique des modèles avec changements structurels : quelques contributions." Aix-Marseille 2, 2004. http://www.theses.fr/2004AIX24012.
This thesis explores the empirical evidence of the instability by uncovering structural breaks in economic and financial time series. In a first time, we were defined the structural change models and reviewed the most important results available in the econometric and statistical literature. Then, we were presented the main contributions of the thesis. Indeed, we were first proposed a detailed discussion of structural breaks in time series models based on parametric and nonparametric approaches. While the first approach broaches the instability problem in the time domain by uncovering structural breaks in time series, the nonparametric approach based on the Priestley evolutionary spectra, generalizing the usual definition of spectra for stationary processes, provides simultaneously the instability characteristics in the time and frequency domains by locating the unstable frequencies and the associated dates. We were proposed the use of bootstrap in connection of testing for structural breaks. The motivation for this lies in the fact that the asymptotic distribution theory of many of the break tests presented in the literature may not always be particularly useful in small-sample situations. The bootstrap turns out to be a very useful tool in that it allows surmounting efficiently these problems. The thesis was finally taken up a problem that has received plenty of attention in the recent time series literature: the relationship between structural breaks and long memory. The goal is to model the series with a process that takes into account the two concepts at the same time to investigate the effect of one on the other
Venel, Stéphanie. "Une Nouvelle approche de la modélisation et du calcul des ballons scientifiques." Rouen, 1997. http://www.theses.fr/1997ROUES086.
Guerfi, Fayçal. "Modélisation et approche analytique des systèmes d'écoulements triphasiques compressibles en milieu poreux." Pau, 1989. http://www.theses.fr/1989PAUU3004.
Kouassi, Eugène. "Approche fréquentielle de la causalité évolutive entre processus aléatoires bivariés non-stationnaires." Montpellier 1, 1990. http://www.theses.fr/1990MON10006.
In the study of causality between stochastic processes, the assumption of stationarity (at least of second order) is often tacitly made. It's possible, indeed, essential to release such assumption (case of nonstationary processes) using evolutionary spectral analysis and timedependant parameters models. Evolutionary causality (i. E time-dependant causality) which is issued results partly from frequency-domain analysis (evolutionary causality test) and from the combination of a set of evolutionary prediction models (arma models and transfer function models with changing parameters)
Friggit, Jacques. "Mécanique statistique des marchés : une approche darwinienne des comportements financiers : application à la dynamique des taux de change." Aix-Marseille 3, 1995. http://www.theses.fr/1995AIX32020.
The dissertation models market behavior in very liquid markets. It assumes that financial behaviors adapt to information not instantaneously but following a darwinian evolution process, then reformulates and solves the problem thus posed by using tools borrowed from statistical mechanics. Some properties of the resulting price process are then compared to actual price processes observed in the foreign exchange market on short time scales. A potential predictor of instabilities is derived. A complete translation of the dissertation into english is available
Bisgambiglia, Paul-Antoine. "Approche de modélisation approximative pour des systèmes à évènements discrets : application à l’étude de propagation de feux de forêt." Corte, 2008. http://www.theses.fr/2008CORT0003.
In this thesis report, we present an approximate modeling approach for discrete events systems. The aim of this research is to develop tools to link modeling and simulation formalism, with fuzzy logic. This new method called iDEVS allows to model and to simulate inaccurate systems. Throughout the manuscript, we discuss various concepts such: take into account inaccuracies with fuzzy sets theory; fuzzy simulation with defuzzification methods…In the first chapter, we present the theories associated with fuzzy logic. In the second chapter, we describe the modeling and simulation concepts, including DEVS formalism. In the third chapter, we explain the method iDEVS, and the tools developed for use. Before concluding, we propose an application of the approach iDEVS to study the spread of forest fires
Lair, Pierre-Olivier. "Contribution à la modélisation, à l'analyse et à la commande des systèmes de production par une approche bond graphs." Besançon, 2000. http://www.theses.fr/2000BESA2058.
Bedou, Isabelle. "Modélisation des Systèmes d'Information Coopératifs : une approche cognitive basée sur la négociation." Montpellier 2, 1998. http://www.theses.fr/1998MON20233.
Marchand, Didier. "Modélisation fonctionnelle du bilan hydrique sur sol cultivé : approche déterministe ou stochastique ?" Grenoble 1, 1988. http://www.theses.fr/1988GRE10130.
Sohier, Joël. "La relation d'échange interorganisationnelle : une approche stratégique et interactive." Dijon, 1997. http://www.theses.fr/1997DIJOE002.
The thesis fits into the debate on the interactive approach of the markets. It integrates the different marketing approaches of the exchange: distribution, business to business marketing and social marketing. This integration is enriched through the knowledge of the other fields of management, organisation theory and strategy. The research is backed by a conceptual set inspired by a political economy paradigm and the transaction cost approach. The paradigm considers the exchange as the meeting-point between two parties: each one trying to obtain something from the other one against something else. The exchange is the product of a social relationship which, even though it is often constrained, is never entirely determined. The inclusion of a strategic construct in the exchange paradigm allows an interactive representation of the transaction. Each party displays a transactional strategy that is the result of his global strategy as well as the structural conditions which surround the exchange. The thesis shows that the interaction of these strategies makes it possible to explain the functioning and the climate of the exchange. This analysis of the exchange, within the strategic aspect of its management, has required developing a methodology that allows the statistical bringing together of both parties concerned. The simple dyadic approach is outdaded to be replaced by an interactive analysis. The paradigm is tested on a data base of 103 dyads composed of manufacturers of knitted articles and their suppliers. Each party has been separately interviewed about their relationship with their partner. Thus a statistical approach has been made possible: the testing of the model is made through an estimate of the influence of variables measured for one party over variables concerning the exchange partner
Dachary-Bernard, Jeanne. "Approche multi-attributs pour une évaluation économique du paysage." Bordeaux 4, 2004. http://www.theses.fr/2004BOR40028.
Pfiffelmann, Marie. "Comptes d'épargne et actifs à lots : une approche comportementale." Université Louis Pasteur (Strasbourg) (1971-2008), 2007. http://www.theses.fr/2007STR1EC08.
This work is devoted to the study of lottery-linked-deposit-accounts (LLDA). As the popularity of these financial assets cannot be understood in the expected utility framework, we adopt a behavioral approach. First, we study the structure of these assets and determine their optimal design in the light of the behavioral models generally proposed in the literature. However, when these models are applied to the financial market, they have to cope with some difficulties. In order to make up for these limitations, we propose an alternative theory of decision making under risk. In the framework of this new theory, it is now possible to determine, without limitation, the optimal design of LLDA
Gelbert, Christine. "Etude de l'intermittence et de la variabilité des champs de précipitation par une approche stochastique." Grenoble 1, 1990. http://www.theses.fr/1990GRE10036.
Favier, Lionel. "Approche numérique par éléments dicrets 3D de la sollicitation d'un écoulement granulaire sur un obstacle." Grenoble 1, 2009. http://www.theses.fr/2009GRE10052.
The analysis of impact pressure by granular flows on obstacles requires an investigation of the drag coefficient. However, in the bibliography, experimental studies cannot reach inner flow properties, in spite of their consideration in its computation. Therefore, in this thesis we propose to determine this coefficient through three dimensional numerical tools, carried out with the discrete element method (DEM), and validated through experimental studies. The experiments consist in a laboratory canal, fully modelled by the DEM. The local contact law includes a normal elastic, hysteretic behaviour with a tangential sliding criterion. The full model validation is deduced from the similarity between experimental and numerical results of the flow's physical parameters and of the impact loading against the obstacle. This validation is obtained without any important calibration of the numerical parameters. Then, the full model is optimized, in terms of time computation and number of studies possibilities, as a granular launcher, in which is only considered the flow-obstacle interaction zone. The flow properties: velocity, thickness, density, are controlled because taken as initial numerical parameters. The effect of flow characteristics, like the Froude number, grains' mean size, or the shape and size of the obstacle, on the drag coefficient, is then analyzed. Finally, further micromechanical investigations are performed to study the effect of an adhesion and cohesion added in the local behaviour
Moulet, Lucie. "Modélisation de l'apprenant avec une approche par compétences dans le cadre d'environnement d'apprentissage en ligne." Paris 6, 2011. http://www.theses.fr/2011PA066636.
Bouissou, Stéphane. "Approche de l'instabilité sismique par l'analyse du glissement saccadé avec un analogue de roche (PMMA)." Montpellier 2, 1998. http://www.theses.fr/1998MON20079.
Sueur, Christophe. "Contribution à la modélisation et à l'analyse des systèmes dynamiques par une approche bond-graph : application aux systèmes polyarticulés plans à segments flexibles." Lille 1, 1990. http://www.theses.fr/1990LIL10088.
Duchêne, Vincent. "Ondes internes en océanographie et cristaux photoniques : une approche mathématique." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://tel.archives-ouvertes.fr/tel-00597514.
Sato-Gaillot, Elizabeth. "Modélisation physique et numérique de l'éjection de matériaux bouillants dans des structures fusibles : étude d'une approche simplifiée." Aix-Marseille 1, 1993. http://www.theses.fr/1993AIX11006.
Chassot, Emmanuel. "Approche écosystémique des pêches : de l'utilisation d'indicateurs à la simulation théorique ; vers un modèle couplé écologie/économie appliqué au Finistère." Rennes, Agrocampus Ouest, 2005. http://www.theses.fr/2005NSARH063.
The overfishing of many fish stocks at the global scale associated with the degradation of marine ecosystems have progressively put into relief the limits of current fisheries managment. The ecosystems have progressively put into relief the limits of current fisheries management. The ecosystem approach to fischeries (EAF), particularly recommended by FAO, calls for modifying the perception of fisheries management in order to include ecosystem considerations. By improving our understanding of population and ecosystem dynamics, and by quantifying the effects of fishing, EAF thus aims to reconcile sustainable exploitation of fisheries resources and conservation. The PhD thesis is part of a European project (“PECHDEV” QLRT-2000-02277), aiming to define a link between the state of the ecosystem, the dynamics of marine exploited populations and the economic sectors of the production region. The case study is the department of Finistère (France) characterized by a high degree of dependence on fishing. The first chapter presents the state of world fisheries in which EAF has progressively emerged, as well as its main objectives and conceptual principles that define the prerequisite to its implementation. The chapter also deals with current methods used inf fisheries science, indicator approaches and ecosystem models all being major tools for an EAF. The second chapter describes the Finistère cas study. The heterogeneity of information available in terms of assessment for the stocks exploited leads to propose a generic methodology in order to define surplus production models, in the perspective of their coupling with the economic model presented in the fifth chapter. A simulation model allows to deal with scaling problems due to the lag between the terrestrial dimension of the economic analysis, and the marine dimension of the fished resources
Gonindard, Melo de Mila Christelle. "Développement d'une approche markovienne pour l'analyse de l'organisation des génomes." Lyon 1, 2005. https://tel.archives-ouvertes.fr/tel-00011674.
Large scale sequencing has given access to many complete genomes. Hidden Markov models are one of the most used statistical methods for the analysis of genomics sequences. The objective of this work is to contribute to the analysis and comprehension of the evolution of genomes. A method for predicting isochores adapted to the human genome was developed. The originality of this approach consists in identifying breaks of homogeneity in the sequences. It also consists in identifying their biological impact, such as the UTRs influence may have on the classification of genes in an isochore. This method was then applied to the genome of the tetraodon, when we discovered the existence of a new mosaic structure
Deslaef, David. "Modélisation numérique du grenaillage de précontrainte : approche tridimensionnelle et dynamique." Troyes, 2000. http://www.theses.fr/2000TROY0009.
Deveaux, Vincent. "Modèles markoviens partiellement orientés. Approche géométrique des automates cellulaires probabilistes." Phd thesis, Rouen, 2008. http://www.theses.fr/2008ROUES004.
The global subject of this thesis is probabilistic cellular automata (PCA). It is divided into two parts. In the first part, we define the notion of partially ordered chains (POC) that generalise PCA. They are defined thought partially ordered specification (POS) in analogy with the statistical mechanics notion of Gibbs measure. We obtain the analogous of Gibbs measure phase space properties characterization of extremal measures, construction/reconstruction starting from single site kernels, criterion of uniqueness. These results are applied to some well-known PCA. The second part is essentially devoted to 1-dimensional PCA with two neighbours and two states. We show two decompositions of space-time configurations in flow of information. Those flows have a geometrical meaning that induce two uniqueness criteria. In appendix, we give a version of the proof of phase transition of the NEC Toom's PCA. The whole thesis is punctuated by simulations
Bisserier, Amory. "Une approche paramétrique de la régression linéaire floue : formalisation par intervalles." Chambéry, 2010. http://www.theses.fr/2010CHAMS021.
System identification is a term gathering tools that identify mathematical models from observations. Within this framework, regression techniques are frequently used. This Ph. D. Thesis deals with the study of parametrical linear regression in an imprecise context. So, measurements and model parameters are imprecise and represented using fuzzy set theory, while inputs are crisp numbers. Existing fuzzy regression techniques present two main limits. On the one hand, the imprecision of identified models is too important, mainly due to the link between imprecision variation and input sign. On the other hand, inclusion is not guaranteed even when a triangular fuzzy model, which should include observations, is identified. In this context, several improvements are introduced and illustrated. Inclusion is guaranteed by the identification of trapezoidal fuzzy models. By applying a shift term to inputs, the model output imprecision becomes independent of input sign, while model linear structure is preserved. Lastly, an optimization criterion which represents the global fuzziness of the model on its definition domain is introduced. It is then possible to improve the precision of the identified model as well as its representativeness. All these concepts are extended to piecewise and multi-inputs linear model identification. The potential of the proposed method is tested on realistic data sets, concerning the identification of polynomial models with appropriate order and multi-linear models. By identifying dynamical models from variations of a market index, problems related to fuzzy regressive models with imprecise inputs are also introduced
Zuber, Emmanuel. "Approche biométrique de la dynamique de réactions antigène-anticorps : cas de deux systèmes automatisés de suivi en temps réel des cinétiques." Lyon 1, 1997. http://www.theses.fr/1997LYO1T113.
Allam, Mohamed. "Sur l'analyse quantitative des réseaux de Petri hybrides : une approche basée sur les automates hybrides." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0157.
Cuille, Pierre. "Approche de la simulation dynamique : application aux procédés discontinus." Toulouse, INPT, 1986. http://www.theses.fr/1986INPT013G.
Berdai, Abdelhamid. "Modélisation et simulation d'un réseau de transport public par une approche multi-agents." Besançon, 2004. http://www.theses.fr/2004BESA2035.
The work presented in this thesis focuses on the modelling and the simulation of bus transportation networks. The proposed approach is the design of a model based on multi-agents paradigm, which takes into account risks affecting the transportation network. These risks can changed according to several temporal or space variations. In order to analyze an urban public transportation system, a model based on multi-agents approach is elaborated. First, we determine the structure of transportations system as being as hierarchical organisations. Such a structure includes roles and their interactions. Then, we define a set of agents and we assign roles for each one. Interactions between agents are modelled by the interaction diagram. To simulate this model, the agent behaviour specification is necessary. The design process of transportation simulator allows us to describe the behaviour of each agent with the statechart formalism and thus we define a set of rules, which simplifies the behavioural agent model. The last step is to implement the simulator from models specified previously. We implement a human-machine interface, its configuration, and its parameter setting. Finally, we evaluate some parameters of transport quality of service by taking account risks which perturb the bus network
Mercier, Catherine. "Approche biométrique de la notion d'itinéraires techniques : application au colza d'hiver." Lyon 1, 1991. http://www.theses.fr/1991LYO10112.
Muñoz-Pardo, José Francisco. "Approche géostatique de la variabilité spatiale des milieux géophysiques : application à l'échantillonnage de phénomènes bidimensionnels par simulation d'une fonction aléatoire." Grenoble 1, 1987. http://www.theses.fr/1987GRE10021.
Chabot, Jean-Luc. "Approche probabiliste relative à l'étude des scénarios d'incendie." Poitiers, 1998. http://www.theses.fr/1998POIT2303.
Buffet, Olivier Bernard Henri. "Une double approche modulaire de l'apprentissage par renforcement pour des agents intelligents adaptatifs." Nancy 1, 2003. http://docnum.univ-lorraine.fr/public/SCD_T_2003_0108_BUFFET.pdf.
These PhD thesis has been interested in two fields of artificial intelligence: reinforcement learning (RL) on the one hand, and multi-agent systems (MAS) on the other hand. The former allows for the conception of agents (intelligent entities) based on a reinforcement signal which rewards decisions leading to the specified goal, whereas the latter is concerned with the intelligence that can result from the interaction of a group of entities (in the perspective that the whole is more than the sum of its parts). Both these tools suffer from various difficulties. The work we accomplished has shown how these tools can serve each other to answer some of these problems. Thus, agents of a MAS have been conceived through RL, and the architecture of a reinforcement learning agent has been designed as a MAS. Both tools appear to be very complementary, and our global approach of a ``progresssive'' design has proved its efficiency
Landry, Alex. "Utilisation d'une approche photogrammétrie-DFN pour l'évaluation des conditions structurales du projet minier souterrain Éléonore." Master's thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26148.
Vergnault, Étienne. "Vers une approche multi-échelle pour l’interaction fluide-structure." Cachan, Ecole normale supérieure, 2009. http://tel.archives-ouvertes.fr/tel-00661195.
Predicting the behaviour of structures subjected to loading by a fluid is a current issue of the aviation industry. Composite materials, whose mass ratio is increasing with each new project, have mechanisms of degradation whose characteristic size is less than a tenth of a millimetre. Inspired from Multiscale methods developed in the laboratory for the simulation of structures, we propose a mixed domain decomposition method for the simulation of incompressible flows. The Navier-Stokes equations are written in Eulerian formalism and solved incrementally. The solution at each time step is obtained iteratively by solving problems on the interfaces and sub domains. The non-linearity associated with the convection term is treated at the sub domain level and problems on the interfaces provide verification of all equations of the original problem. We then introduce a global problem posed on all interfaces. This innovative macroscopic problem based on the condition of incompressibility of the flow accelerates the convergence of the iterative strategy. We address finally the coupling with a method of fictitious domain, whose early development has yielded promising results. The proposed methods are implemented in a finite element code and illustrated on two-dimensional examples
Méda, Bertrand. "Une approche dynamique des flux d’éléments et d’énergie des ateliers de production avicole avec ou sans parcours : Conception et application du modèle MOLDAVI." Rennes, Agrocampus Ouest, 2011. https://tel.archives-ouvertes.fr/tel-00662627v2.
Given global efforts towards sustainability, poultry production must find ways to optimise input use, reduce waste production and minimise energy consumption. To meet these objectives, MOLDAVI, a dynamic model simulating fluxes of C, N, P, K, Cu, Zn, water and energy at the scale of the rearing system, was developed. It is composed of an “Animal” module simulating animal performances (growth, feed consumption, excretion, heat production), a “Housing” module simulating energy production and use and gaseous emissions (H2O, CO2, NH3, N2O, N2, CH4) and an optional “Outdoor run” module simulating gaseous emissions from the proportion of total droppings excreted there. However, as there is little knowledge about rearing systems with outdoor access, experiments on two organic broiler-production systems were conducted to collect data on the quantity of droppings and gaseous emissions of NH3, N2O and CH4 in the house and on the outdoor run. Ultimately, MOLDAVI can be associated with other farm-scale modelling approaches or used in a combined approach with Life Cycle Assessment methodology
Mezghani, Saloua. "Approche multimodèle pour la détermination d'une commande discrète d'un système incertain." Lille 1, 2000. http://www.theses.fr/2000LIL10170.
Le but general est de concevoir un superviseur qui permet de generer la loi de commande a appliquer au systeme, tout en assurant les performances desirees. A partir des modeles et des mesures obtenues, on produit ce qu'on appelle les residus. Ces residus sont definis a partir des variables, ou a partir des parametres. On obtient ainsi, la validite de chaque modele qui conduit a une fusion optimale assurant la stabilite du systeme malgre les evolutions de processus normales ou accidentelles. Lors des variations brusques des parametres, si l'action de commande n'atteint pas les performances desirees, alors une re-initialisation de l'etat des modeles peut s'averer necessaire. Pour chaque modele, l'etat est re-initialise a la valeur de l'etat estime du systeme pour ce meme modele quand celui-ci diverge. L'ajout d'un observateur pour chaque modele permet d'estimer l'etat du systeme pour le modele correspondant et d'ameliorer egalement la valeur de la validite de chaque modele pour realiser les buts desires
Seiller, Gregory. "Évaluation de la sensibilité des projections hydrologiques au choix des outils hydro-météorologiques globaux conceptuels - Approche multimodèle." Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/30064/30064.pdf.
Modeling climate change impacts on water resources remains one of the major challenges for the scientific community. This task is complex and contains numerous cumulated uncertainties all along the modeling process, from the greenhouse gas scenarios definition to the hydrological projections. All the modeling tools can thus potentially affect our ability to render a diagnosis of the impacts of climate changes on water resources. In this context, modeling uncertainty related to 20 lumped conceptual hydrological models, 24 potential evapotranspiration formulations, and 7 snow modules was evaluated on two catchments: au Saumon (Province of Quebec, Canada) and Schlehdorf (State of Bavaria, Germany). This work first assessed the transposability in time of the hydrological models and examined the interest of the multimodel approach in a climate change context. Then, contribution of the different tools to cumulated uncertainty is evaluated, followed by an investigation of individual sensitivity origins. This analysis was based on performance criteria, discharge graphical displays, statistics tools, and hydrological indicators of changes in water resources. More, uncertainties related to climatic members are also appraised on the Quebec catchment to allow a direct comparison with the principal studied tools. Results demonstrated that our capacity to render a diagnosis of the impacts of climate change on water resources on the two studied catchments was highly connected to the choice of the hydro-meteorological lumped modeling tools. Each one contributed to the total uncertainty; however, with a larger prevalence for the potential evapotranspiration formulations and hydrological models, snow modules being more neutral. Nevertheless, comparative analysis showed that the selection of a climatic member was affecting the total uncertainty the most. This research proposed a detailed analysis on our capacity to realise a diagnosis of the impacts of climate change on water resources for two studied catchments and provided a specific and original methodology directly applicable and adjustable to other hydro-climatic contexts.
Tall, Demba. "Le redoublement au post-primaire général public dans la région du Centre-Ouest du Burkina Faso : analyse des principales caractéristiques liées aux représentations sociales et aux modèles d’intervention éducative véhiculés par les personnels enseignants et les directions des écoles." Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/9873.
Rugishi, Muhindo G. "Modélisation des fluctuations macroéconomiques et comparaison des performances de modèles dynamiques d'équilibre général estimés : une approche par l'estimation bayésienne et les modèles à facteurs." Doctoral thesis, Université Laval, 2007. http://hdl.handle.net/20.500.11794/19318.
Hugot, Alexandre. "Modélisation des écoulements gravitaires catastrophiques par une approche objet dynamique : érosion, transport, dépôt." Paris 6, 2000. http://www.theses.fr/2000PA066567.
Braesch, Christian. "Approche de modélisation du système de production d'une entreprise manufacturière." Besançon, 1989. http://www.theses.fr/1989BESA2011.
Saunier, Sébastien. "Influence d'un gradient thermique sur le frittage d'alumines : approche expérimentale, modélisation et simulation numérique." Saint-Etienne, EMSE, 2006. http://www.theses.fr/2006EMSE0004.
With the development of the new sintering processes, thermal cycles become more and more shorter. Such thermal cycles lead to thermal gradients development into the sample. Then, a question can be asked : What are the consequences of these gradients on material sinterability. Within this framework, this study aims to bring a better understanding of the temperature gradient effects on alumina sintering. For that, a furnace was developed. Thanks to this furnace, the effects of a thermal gradient have been investigated independently of a fast heating rate. Comparisons were performed between sintering with and without thermal gradient (for the same heating rate and same annealing period). Experimental results showed that a thermal gradient applied in the initial stage of sintering conducts to a delay of the specific surface area drop and finally to an increase of densification. Moreover, it was shown that a thermal gradient applied at the beginning of sintering can modify the impurities' mobility. If the gradient is applied during the intermediary and final stage of sintering, it leads to important changes in the characteristics of the final material : an increase of densification and a reduction of the average particle size occur simultaneously. These results were correlated with the development of internal stresses in the material. From these considerations and characteristics of the studied powders, a model of sintering was developed using bingham-like constitutive equations. The simulations carried out starting from this model showed, contrary to the model classically used to describe sintering (newtonian model), a good adequacy with the experimental results
Morell, Alaia. "Dynamiques éco-évolutives des espèces exploitées en Mer du Nord en réponse à des variations biotiques et abiotiques de l'environnement." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR079.
Global change scenarios are valuable for guiding management and governance strategies, stimulating decision making, and increasing collective awareness of future biodiversity trends. The degree of realism and integration of ecosystem models used for this purpose is constantly improving, but they still often neglect the evolution of marine populations in future projections. However, marine populations adapt to global changes, either through phenotypic plasticity or evolution, through modifications of their biological characteristics such as life history traits, physiological and bioenergetic traits. The challenge of this thesis is to develop an ecosystem model that allows the exploration of biodiversity scenarios at intra- and inter-specific scales by explicitly representing the phenotypic plasticity of life history traits, their genetic variability, selection and evolution under the combined influence of fisheries and climate change, and the resulting genetic drift and loss of genetic diversity. Applied to the North Sea, this new model is used to understand the processes responsible for changes in life history traits, whether they are of plastic or evolutionary origin. On the one hand, the bioenergetic processes underlying plastic changes are studied by an original approach comparing the differences between the fundamental and realized thermal response curves for different species and life history stages. On the other hand, changes in life history traits are explored through an evolutionary lens by taking into account multiple selection pressures such as fishing, prey-predator interactions and climate change.The integration of plastic and evolutionary processes in ecosystem models allows to describe the inter-individual variability of biological traits and to understand their temporal trends observed in the marine environment. In this way, it responds to the crucial issue of credibility of intra- and inter-specific biodiversity projections under scenarios combining climate and fisheries. The integration of these processes will also allow to quantify more precisely the synergistic and antagonistic effects of these two pressures and to take into account the capacity of populations to adapt to global changes in order to estimate more reliably their resilience
Jeleva, Meglena. "Les comportements d'assurance des agents : une approche par les modèles de décision non-additifs." Paris 1, 1997. http://www.theses.fr/1997PA010084.
The purpose of this thesis is to study the behaviors on the insurance market of agents whose preferences under uncertainty are represented using non-additive models which generalize the expected utility and make possible to separate the attitude towards uncertainty from the attitude towards wealth. This preferences representation, together with the assumption that agents don't know precisely the probability distribution of their losses, makes the modelling of insurance behaviors more realistic and allows a better understanding of the choices observed on insurance markets. The first chapter of the thesis is a presentation of the models of decision making under probabilized uncertainty (risk) and under non-probabilized uncertainty. In the second one, we study the demand for insurance when the agent faces only one source of risk. Firstly, we assume that the agent is able to locate the probability distribution of potential losses into a given set of distributions, his preferences are then represented by the Jaffray model. After that, we consider a general non-probabilized uncertainty framework where preferences are represented by the choquet expected utility. In the third chapter, a background risk is introduced. The impact of this additional source of risk on the demand for insurance on the insurable risk is examined in the cases when the two risks are comonotonic and anti-comonotonic. The forth chapter deals with the contracts offered by a monopoly insurer in an adverse selection framework, when the insurees have only imprecise information on their loss probability. The last chapter of the thesis is an empirical examination of the choices of life insurance contracts. The aim of this study is to test the impact of life expectations on the contracts bought by the agents
Garcia, de Vicuña José Luis. "Etude du comportement à fort signal des convertisseurs continu-continu : approche par un modèle discret non linéaire." Toulouse 3, 1992. http://www.theses.fr/1992TOU30009.