Дисертації з теми "Synchronisation des modèles"
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Bodgi, Joanna. "Synchronisation piétons-structure : Application aux vibrations des passerelles souples." Phd thesis, Ecole des Ponts ParisTech, 2008. http://pastel.archives-ouvertes.fr/pastel-00004784.
Poquet, Christophe. "MODÈLES STOCHASTIQUES INTERAGISSANTS : SYNCHRONISATION ET RÉDUCTION À UN SYSTÈME DE PHASES." Phd thesis, Université Paris-Diderot - Paris VII, 2013. http://tel.archives-ouvertes.fr/tel-00966053.
Corson, Nathalie. "Dynamique d'un modèle neuronal, synchronisation et complexité." Phd thesis, Université du Havre, 2009. http://tel.archives-ouvertes.fr/tel-00453912.
Renversez, Gilles. "Modèles de neurones pour les neurosciences : des canaux ioniques à la synchronisation." Paris 11, 1997. http://www.theses.fr/1997PA112354.
We firstly recall the main characteristics and properties of biological neurons and we describe the Hodgkin-Huxley's model of neuronal electric activity. We then propose a model which allows to compute the spatiotemporal variations in the somatic transmembrane potential during an action potential. It takes into account bath the spatial distribution of ionic channels on a spherical body cell and their stochastic dynamics. This work has been motivated by recent experimental results which reported heterogeneous electric-field patterns on the somatic membrane during the action potential firing. We show that only inhomogeneous spatial distributions of ionic channels can create such heterogeneous patterns. Then, we describe a known method of dimensional reduction scheme which allows to link models using many variables to define neuronal dynamics to reduced systems. We study the dynamics of several such reduced models according to time-dependent external stimulation. In the following part, we study in detail the synchronization of two neurons mutually coupled with biologically plausible time-delayed inhibition. The neuron model is a two component dynamical system which can generate action potential. We obtain analytical results on the synchronization using piecewise linear approximations in neurons phase space. We show that the coincidence synchronization is stable versus the noise introduced in neuronal dynamics. Finally, we numerically study the dynamics of a globally connected network of neurons coupled with time-delayed inhibition. We use two types of quantitative measures to assess the level of synchrony of the network. We show that the synchronization of action potentials is stable versus noise even in an heterogeneous network and that the exchange of few action potentials is sufficient to get this synchronization. We notice that such a network of inhibitory neurons can generate membrane potential oscillations of the same type as the ones observed-in experiments
Libeaut, Xavier. "Multiflots dynamiques avec contraintes de synchronisation de ressources." Angers, 2013. https://hal.archives-ouvertes.fr/tel-01104353.
This research focuses on a multi-commodity flow problem arising in courier and small-package delivery services. In the first part, we present the context of the study and review relevant literature. In the second part, we introduce two different mix integer programming models for the problem and discuss valid inequalities and surrogate constraints helpful to straighten the formulations. In the third part, we propose a method to compute a lower bound and 5 heuristic approaches to solve the problem. The latter include tailored implementations of the capacity scaling heuristic and the large neighborhood search framework. In the last part of the manuscript, we first introduce a methodology to generate test instances for the problem. Then, we discuss and analyze extensive computational experiments carefully crafted to assess the performance of the proposed solution methods
Viot, Louis. "Couplage et synchronisation de modèles dans un code scénario d’accidents graves dans les réacteurs nucléaires." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLN033/document.
This thesis focuses on solving coupled problems of models of interest for the simulation of severe accidents in nuclear reactors~: these coarse-grained models allow for fast calculations for statistical analysis used for risk assessment and solutions of large problems when considering the whole severe accident scenario. However, this modeling approach has several numerical flaws. Besides, in this industrial context, computational efficiency is of great importance leading to various numerical constraints. The objective of this research is to analyze the applicability of explicit coupling strategies to solve such coupled problems and to design implicit coupling schemes allowing stable and accurate computations. The proposed schemes are theoretically analyzed and tested within CEA's procor{} platform on a problem of heat conduction solved with coupled lumped parameter models and coupled 1D models. Numerical results are discussed and allow us to emphasize the benefits of using the designed coupling schemes instead of the usual explicit coupling schemes
Pascual, Nathalie. "Horloges de synchronisation pour systèmes haute sécurité." Montpellier 2, 1992. http://www.theses.fr/1992MON20145.
Roux, Sébastien. "Modèles dynamiques en tomographie - Application à l'imagerie cardiaque." Phd thesis, Grenoble 1, 2004. http://tel.archives-ouvertes.fr/tel-00007803.
Guiraud, Pierre. "Route vers la synchronisation dans les réseaux d'applications couplées." Aix-Marseille 1, 2004. http://www.theses.fr/2004AIX11021.
Legendre, Anthony. "Ingénierie système et Sûreté de fonctionnement : Méthodologie de synchronisation des modèles d'architecture et d'analyse de risques." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLC083/document.
Classical organization in disciplinary silos in the industry reaches its limits to manage and control complexity. Problems are discovered too late and the lack of communication between experts prevents the early emergence of solutions. This is why it is urgent to provide new collaborative approaches and ways to exchange the models contents between various engineering fields, early and all along the development cycle. In this context, we are particularly interested in a synchronization approach of models between two engineering fields: system architecture design and dependability analysis.This work proposes a collaborative approach of synchronization of models. It takes into account the study contexts, applied processes, applied methods and viewpoint produced by engineers. Contributions address issues at levels of practices, concepts, implementation, applications and implementation of model synchronization
Mauran, Philippe. "Un modèle pour la spécification de la synchronisation à l'aide de contraintes." Montpellier 2, 1990. http://www.theses.fr/1990MON20036.
Arthaud, Geoffrey. "Apports de modèles de comparaison structurelle et sémantique à la synchronisation de la maquette numérique de construction." Phd thesis, Ecole des Ponts ParisTech, 2007. http://pastel.archives-ouvertes.fr/pastel-00004854.
Emako, Kazianou Casimir. "Études de modèles de chimiotactisme à deux espèces." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066045/document.
This thesis is concerned about cellular motion of a population composed of two species in interaction through chemical cues. The chemical cues to which the two species are subject are of different kind.They can be internal (produced by the two species) or external (present in the meduim and consommed by the two species). Synchronising and non-synchronising effects are observed during the migration of the population formed by two different strains of E.Coli.Although separately, red bacteria E.Coli travel twice as fast as green bacteria E.Coli, put together, they travel or split depending on the percentage of the faster bacteria in the population. This experimental result is explained by a two-species parabolic macroscopic chemotaxis model for which the existence and non-existence of traveling pulses are showed. The parabolic macroscopic model is derived from microscopic models which describe the individual motion of cells. The synchronising and non-synchronising effect is also encountered in dynamics of the two-species dirac masses after blow-up of classical solutions in a two-species model for aggregation. A method to design both well-balanced and asymptotic preserving schemes is proposed. This method is tested to chemotaxis and radiative transport kinetic models
Bettaieb, Sabeur. "Contribution à la spécification d'une environnement de conception collaborative intégrateur d'expertises métier hétérogènes." Grenoble INPG, 2006. http://www.theses.fr/2006INPG0014.
THIS THESIS CONTRIBUTES TO THE SPECIFICATION OF A KEY ELEMENTS FOR COLLABORATIVE DESIGN ENVIRONMENTS. THE DOCUMENT IS DIVIDED INTO TWO PARTS: THE FIRST PART PROPOSES A STATIC MODEL FOR THE COLLABORATIVE DESIGN ENVIRONMENT; THE SECOND PART STUDIES THE DYNAMIC ASPECT OF THIS ENVIRONMENT. THUS WE FIRST IDENTIFY THE KEY DESIGN CONCEPTS, AND SHOW THE NEED FOR JOINTL Y CONSIDERING THE THREE MODELS OF PRODUCT, PROCESS AND ORGANIZATION. WE DISCUSS THEREAFTER THE WAYS THESE MODELS ARE INTEGRATED AND RECOMMEND : A LlGHT LANGUAGE, AND AN INTEGRATIVE TECHNOLOGY TO ENRICH PROGRESSIVEL Y THE SHARED MODEl THROUGHOUT THE PRODUCT LlFECYCLE. LN THE REMAINDER OF THE DOCUMENT WE TREAT HOW TO MAINTAIN THE DESIGN ENVIRONMENT lN A CONSISTENT STATE. WE RECOMMEND THEN A SIMUL TANEOUS ACCESS MODE THAT DOESN'T DISTURB THE DESIGNERS ACTIVITIES. HOWEVER WE PROPOSE ALSO AN ASSISTANCE FRAMEWORK TO MERGE HETEROGENEOUS EXPERT MODELS. FINALLY WE PROPOSE AN ANTICIPATED NOTIFICATION TECHNIQUE TO ALERT THE DESIGNERS OF THE NEXT DESIGN CHOICES WITHOUT DISTURBING THE CURRENT DESIGN STUDIES
Pellegrin, Xavier. "Oscillations dans des modèles mathématiques issus de la biologie." Paris 7, 2014. http://www.theses.fr/2014PA077263.
Ln this report, we focus on mathematical analysis of two models coming from biology. The first model, a Kuramoto model, describes the time-evolution of a large number of mean-field coupled phase oscillators. The second one is an original oscillation model, based on a singuiar perturbation of a delayed differential equation. It had been introduced in relation with oscillatory patterns observed in neural networks, and it is subject fo mathematical analysis since the 1980's
Chettaoui, Hanène. "Interopérabilité entre modèles hétérogènes en conception coopérative par des approches d'Ingénierie Dirigée par les Modèles." Phd thesis, Grenoble INPG, 2008. http://tel.archives-ouvertes.fr/tel-00580737.
Lemoine, David. "Modèles génériques et méthodes de résolution pour la planification tactique mono-site et multi-site." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2008. http://tel.archives-ouvertes.fr/tel-00731297.
Châvez, Mario. "Analyse de signaux SEEG intercritiques : : apport de modèles dynamiques non linéaires." Rennes 1, 2001. http://www.theses.fr/2001REN10075.
Torres, Ortiz Flor. "Modèles et observateurs pour les systèmes d'écoulement sous pression. Extension aux systèmes chaotiques." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00586334.
Torres, Ortiz Flor Lizeth. "Modèles et observateurs pour les systèmes d'écoulement sous pression. Extension aux systèmes chaotiques." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENT005/document.
This work mainly deals with the application of nonlinear observers for the detectionof leaks (single, sequential and simultaneous) in pipes under pressure. Theproposed observers were conceived from a spatially discretized version of the waterhammer equations. This version was obtained using the finite difference method ,as an alternative to the orthogonal collocation method also considered. The discretemodels, as well as some observers were validated by a set of experiments realizedin test pipes. This work also gave rise to a new version of high gain observers fornon-uniformly observable systems. Firstly used for the purpose of leak detection,it was successfully applied to the synchronization of chaotic systems with unknownparameters as well. Its presentation includes a formal convergence proof, as well assimulation and experimental results
Este trabajo trata principalmente la aplicación de observadores no lineales parala detección de fugas (únicas, secuenciales y simultaneas) en tuberías bajo presión.Los observadores que aquí se presentan fueron concebidos a partir de una versióndiscreta (espacialmente) de las ecuaciones del golpe de ariete. Tal versión se logróutilizando el método de diferencias finitas, y como alternativa el método decolocación ortogonal. Los modelos discretos, así como ciertos observadores, fueronvalidados mediante una serie de experimentos realizados en tuberías de ensayo.Este trabajo también dio origen a una nueva versión de observadores de granganancia para sistemas no uniformemente observables, la cual se utilizó para ladetección de fugas, así como para la sincronización de sistemas caóticos con parámetrosdesconocidos. Su presentación incluye resultados de convergencia formales,en simulación, y experimentales
Figueiredo, Almeida Sofia José. "Synchronisation d'oscillateurs biologiques : modélisation, analyse et couplage du cycle cellulaire et de l’horloge circadienne." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4239/document.
The cell division cycle and the circadian clock are two fundamental processes of cellular control that generate cyclic patterns of gene activation and protein expression, which tend to be synchronous in healthy cells. In mammalian cells, the mechanisms that govern the interactions between cell cycle and clock are still not well identified. In this thesis we analyze these two biological oscillators, both separately and as a coupled system, to understand and reproduce their main dynamical properties, uncover essential cell cycle and clock components, and identify coupling mechanisms. Each biological oscillator is first modeled by a system of non-linear ordinary differential equations and its parameters calibrated against experimental data: the cell cycle model is based on post-translational modifications of the mitosis promoting factor and results in a relaxation oscillator whose dynamics and period are controlled by growth factor; the circadian clock model is transcription-based, recovers antiphasic BMAL1/PER:CRY oscillation and relates clock phases to metabolic states. This model shows how the relative duration of activating and repressing molecular clock states is adjusted in response to two out-of-phase hormonal inputs. Finally, we explore the interactions between the two oscillators by investigating the control of synchronization under uni- or bi-directional coupling schemes. Simulations of experimental protocols replicate the oscillators’ period-lock response and recover observed clock to cell cycle period ratios such as 1:1, 3:2 and 5:4. Our analysis suggests mechanisms for slowing down the cell cycle with implications for the design of new chronotherapies
Fresnel, Emeline. "Etude comparative des performances des ventilateurs de domicile et analyse des interactions patient-ventilateur en ventilation non invasive." Rouen, 2015. http://www.theses.fr/2015ROUES048.
Noninvasive ventilation can be defined as a modality of treatment for chronic respiratory failure. Nowadays, it is sufficiently often prescribed to motivate test bench studies whose objectives are to evaluate and compare ventilators performances. To provide reliable and reproducible assessments, we revisited many aspects of test bench studies and developed a parametric procedure for testing ventilators. We initially focused our attention on the modeling of a physiological inspiratory effort which, when driving three pathophysiological lung models, allows to simulate a realistic cohort of patients. The development of this procedure required to introduce a clear and motivated terminology, as well as to unify the parameter settings of the ventilators. It was then possible to characterize the ventilators synchronizability, defined as the ability of the device to synchronize with the different pulmonary models it was connected to. These performances depend on the mechanics and dynamics of the lung model. Providing the practitioners with reports and tools for comparing ventilators on a dedicated website should facilitate the choice of a ventilatory assistance device adapted to each patient. This works was also devoted to the use of a dynamical model for the patient-ventilator system which allowed us not only to review most of the asynchrony events observed in clinics but also to explain their underlying mechanisms. Linking theoretical and experimental results offers us a perspective for identifying the ventilators operating strategies, a required step to improve patient-ventilator interactions
Abi, Abdallah D. "Nouvelle approche pour l'amélioration de la synchronisation en IRM cardiaque, modélisation de l'effet magnétohydrodynamique." Phd thesis, Université de Technologie de Compiègne, 2007. http://tel.archives-ouvertes.fr/tel-00283315.
Berriche, Aroua. "Contribution à l’analyse de cohérence des modèles système, multi-physique et sûreté de fonctionnement." Thesis, CY Cergy Paris Université, 2020. http://www.theses.fr/2020CYUN1105.
The development of a mechatronic system involves different designers having various viewpoints on the overall system to handle its complexity. Consequently, multiple models are created from a variety of domains such as mechanical, electronic, and software engineering. These models use different formalisms, modeling languages, and tools to address specific concerns. The major challenge of this approach is to identify and solve any potential inconsistency between models in order to minimize costs and development time before the verification and validation phases. This paper proposes a new collaborative methodology to maintain consistency between different engineering disciplines at an early stage of the development cycle of mechatronic systems. We apply a model synchronization approach to actively check for model consistency in a continuous way during the multidisciplinary design process. As a novel contribution of this thesis, we demonstrate how model transformation techniques can be employed; firstly, to abstract various engineering models in a common formalism based on graph theory and, secondly, to update models with appropriate changes evaluated by a project manager. We also show how to detect the differences automatically, and we discuss where designer decisions are essential
Rio, Maxime. "Modèles bayésiens pour la détection de synchronisations au sein de signaux électro-corticaux." Phd thesis, Université de Lorraine, 2013. http://tel.archives-ouvertes.fr/tel-00859307.
Ducom, Jean-Christophe. "Codage temporel et apprentissage dans les réseaux de neurones." Aix-Marseille 1, 1996. http://www.theses.fr/1996AIX11041.
Rodriguez, Dima. "Nouvelle approche pour l'amélioration de la synchronisation en IRM cardiaque, modélisation de l'effet MagnétoHydroDynamique." Compiègne, 2007. http://www.theses.fr/2007COMP1712.
During cardiac Magnetic Resonance Imaging the ElectroCardioGram recorded for synchronization is highly corrupted by various electromagnetic artifacts obstructing correct detection of the cardiac cycle. One of the contaminating sources is the MagnetoHydroDynamic effect that is due to the movement of the blood’s charged particles in the magnetic environment. In this work, a reliable method for double synchronization on the cardiac and respiratory rhythm is developed which efficiently enhances the quality of high resolution cardiac MR images. The major alterations of human ECG signals are assessed using time and frequency domain analysis. Then, in order to predict this artifact’s contamination levels, various flow models of blood in a magnetic field are studied. The effects of the magnetic field on the flow were shown, and induced surface voltages, liable to alter the ECG waveform, are estimated
Andrade, Porras Liliana Lilibeth. "Principes et réalisation d'une interface de synchronisation interopérable entre modèles de calcul SystemC AMS pour le prototypage virtuel optimisé de systèmes multi-disciplines." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066003/document.
The design of embedded systems is currently an increasingly complex problem. These systems tend to become heterogeneous in the sense that they require the integration of components described by means of different physical/engineering disciplines, for example, electrical, optical, thermal, mechanical, chemical, or biological. Besides, these disciplines can be described under different time domains, for example, Discrete Event (DE), Discrete Time (DT), or Continuous Time (CT). To address this problem, designers require modeling and simulation tools to describe the system’s components under different time domains and synchronize them in the same simulation environment. We explore the possibilities of modeling, simulating and synchronizing multi-disciplinary systems in the same environment, using as reference the SystemC Analog/Mixed-Signal (AMS) simulation standard. We analyze the method introduced in SystemC AMS for synchronizing the DE and DT domains, and we identify its drawbacks. Besides, we introduce a new formalization of the synchronization problem, which is used to detect issues in a model before simulation. We propose a simulator prototype called SystemC Multi-Disciplinary Virtual Prototyping (MDVP), which is implemented as an extension of SystemC. It allows the modeling, and the generic hierarchical elaboration and simulation of multi-disciplinary systems, by means of different Models of Computation (MoCs). To build the MDVP simulator, we introduce a synchronization principle to handle interactions between MoCs. In addition, we introduce a methodology to add, in the simulator prototype, MoCs described under different time domains. We apply this methodology to add a Timed Data Flow MoC in SystemC MDVP. This MoC implements the DT semantics introduced by the SystemC AMS standard, and is based on the synchronization principle between the DE and DT domains. Using the TDF MoC, we implement and simulate a case study of a vibration sensor model and its digital front end circuit. This case study includes a feedback loop and several interactions between the DE and DT domains
Guetmi, Nadir. "Modèles de conception pour des applications collaboratives dans le cloud." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2016. http://www.theses.fr/2016ESMA0016/document.
Nowadays we assist to an enormous progress of mobile collaborative applications. These applications take advantage of the increasing availability of communication networks and the impressive evolution of mobile devices. However, even with a developing acceleration, they are still poor in resources (short life of batteries andunstable network connections) and less secure. In the context of our work, we propose a new approach based on the deployment of mobile collaboration tasks to the cloud. The management of efficient virtualization ensuring continuity of collaboration in peer-to-peer networks is a very difficult task. Indeed, the dynamic aspect of the groups (where users can join, leave or change groups) and a vulnerability to failures can affect the collaboration.In addition, the design of such applications must consider the heterogeneity of cloud and mobile environments.Unlike existing works, we propose a reusable high-level architecture based on patterns design, which can be easily adapted to heterogeneous clouds and mobile environments. Our models have been used as basis for the design of:(i) MidBox, a virtual platform for running mobile collaborative applications on a private cloud and (ii) MobiRDFa decentralized cloud service for real-time manipulation of knowledge via shared RDF documents
Layec, Alan. "Développement de modèles de CAO pour la simulation système des systèmes de communication : application aux communications chaotiques." Limoges, 2006. http://aurore.unilim.fr/theses/nxfile/default/49eee2a7-fa1c-434a-884d-de2752d90bf1/blobholder:0/2006LIMO0006.pdf.
This work deals with the modelling and the simulation of communication chains in a system level environment. A first part develops CAD models used in digital transmission chains and gives principles of simulation for the evaluation of the BER and the parallel computation. A behavioural model of type-2 frequency synthesizer is then given. Numerical computations realized in post processing of a synthesizer working at 13GHz, allows the computation of the output spectra and the probability density of the jitter. The last part of the manual presents a chaotic frequency hopping system built with frequency synthesizers working at 2. 5-2. 52GHz and based of the self synchronisation principle of quasi-chaotic digital encoders/decoders. The behavioural model developed in the first part finally allows the simulation of the secure communication system
Ait, Haddadene Syrine Roufaida. "Modèles et méthodes pour la gestion logistique optimisée dans le domaine des services et de la santé." Thesis, Troyes, 2016. http://www.theses.fr/2016TROY0027/document.
This work addresses the vehicle routing problem (VRP) including timing constraints: time windows (TW), synchronization (S) and precedence (P), applied in Home Health Care sector; giving the VRPTW-SP. This problem consists in establishing a daily caregivers planning to patients' homes asking for one or several services. We have started by considering the problem as a single objective case. Then, a bi-objective version of the problem is introduced. For solving the single-objective problem, a Mixed Integer Linear Program (MILP), two constructive heuristics, local search procedures and three local search based metaheuristics are proposed : a Greedy Randomized Adaptive Search procedure (GRASP), an Iterated Local Search (ILS) and a hybrid approach (GRASP × ILS). Regarding the bi-objective VRPTW-SP, different versions of multi-objective evolutionary algorithm, including various local research strategies are proposed: the Non-dominated Sorting Genetic Algorithm version 2 (NSGAII), a generalized version of this latter with multiple restarts (MS-NSGAII) and an Iterated Local Search combined with the Non-dominated Sorting concept (NSILS). All these algorithms have been tested and validated on appropriate instances adapted from the literature. Finally, we extended the VRPTW-SP on a multi-period planning horizon and then proposed a MILP and a matheuristic approach
Cornet, Jérôme. "Séparation des aspects fonctionnels et non-fonctionnels dans les modèles transactionnels des systèmes sur puce." Grenoble INPG, 2008. http://www.theses.fr/2008INPG0029.
The work presented in this dissertation deals with modeling and formalizing models of Systems-on-Chip at the Transaction Level (TLM). These models complement traditional RTL models, allowing among others the development of the embedded software before RTL or the chip is available. Other activities making use of TLM, such as performance evaluation, require additional details in the models, notably time or behavior linked to time. We propose a study covering a novel technique that allows to enrich functional TL Models with additional information, expressed in plain SystemC. This technique keeps the added information separated from the original functional model, and guarantees functionality preservation. Our study is backed by an original formalization of SystemC, that does not require an explicit model of the scheduler. This formalization also allows local reasoning, at the level of the components of the mode!
Egret, Paul. "Synchronisation des flux physiques et financiers : mise en évidence de l'échec du déploiement d'un ERP au travers d'une étude de cas." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-01059804.
Soumagne, Jérôme. "An in-situ visualization approach for parallel coupling and steering of simulations through distributed shared memory files." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14643/document.
As simulation codes become more powerful and more interactive, it is increasingly desirable to monitor a simulation in-situ, performing not only visualization but also analysis of the incoming data as it is generated. Monitoring or post-processing simulation data in-situ has obvious advantage over the conventional approach of saving to—and reloading data from—the file system; the time and space it takes to write and then read the data from disk is a significant bottleneck for both the simulation and subsequent post-processing steps. Furthermore, the simulation may be stopped, modified, or potentially steered, thus conserving CPU resources. We present in this thesis a loosely coupled approach that enables a simulation to transfer data to a visualization server via the use of in-memory files. We show in this study how the interface, implemented on top of a widely used hierarchical data format (HDF5), allows us to efficiently decrease the I/O bottleneck by using efficient communication and data mapping strategies. For steering, we present an interface that allows not only simple parameter changes but also complete re-meshing of grids or operations involving regeneration of field values over the entire computational domain to be carried out. This approach, tested and validated on two industrial test cases, is generic enough so that no particular knowledge of the underlying model is required
Le, Chevalier Vincent. "Cadres formels pour la simulation des peuplements hétérogènes de plantes en compétition pour les ressources." Phd thesis, Ecole Centrale Paris, 2010. http://tel.archives-ouvertes.fr/tel-00493525.
Soumagne, Jérome. "An In-situ Visualization Approach for Parallel Coupling and Steering of Simulations through Distributed Shared Memory Files." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2012. http://tel.archives-ouvertes.fr/tel-00788826.
Sirovich, Roberta. "Mathematical models for the study of synchronization phenomena in neuronal networks." Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10027.
The spike train, i. E. The sequence of the action potential timings of a single unit, is the usual data that is analyzed in electrophysiological recordings for the description of the firing pattern which is supposed to characterize a certain type of cell. . We present the results obtained describing the firing activity of a small network of neurons with a mathematical jump diffusion model. That is the membrane potential as a function of time is given by the sum of a stochastic diffusion process and two counting processes that provoke jumps of constant sizes at discrete random times. Different distributions are considered for such processes. Two main results emerge. The first one is that interspike intervals (ISI) histograms show more than one peak (multimodality) and exhibit a resonant like behavior. This fact suggests that in correspondence of each mode (i. E. The lag of the maxima) the cell has a higher probability of firing such that the the lags become characteristic times of the cell which could be modulated under physiological conditions. The second main result concerns the role of inhibition in neuronal coding. Indeed we show that the inhibitory inputs may facilitate the transmission of the spikes generated by the excitatory inputs. This fact suggests that inhibitory cells are not only involved in keeping balanced the excitability of the cell but that they may also play a key role in the information process. Such kind of models requires to improve the algorithms to simulate the first passage time through a threshold of a stochastic process. So that the second part of this manuscript is dedicated to a a purely theoretical study on multidimensional bridge processes
Métivier, David. "Modèles cinétiques, de Kuramoto à Vlasov : bifurcations et analyse expérimentale d'un piège magnéto-optique." Thesis, Université Côte d'Azur (ComUE), 2017. http://www.theses.fr/2017AZUR4074/document.
Long-range interacting systems are known to display particular statistical and dynamical properties.To describe their dynamical evolution, we can use kinetic equations describing their density in the phase space. This PhD thesis is divided into two distinct parts. The first part concerns our collaboration with an experimental team on a Magneto-Optical Trap. The physics of this widely-used device, operating with a large number of atoms, is supposed to display effective Coulomb interactions coming from photon rescattering. We have proposed experimental tests to highlight the analog of a Debye length, and its influence on the system response. The experimental realizations do not allow yet a definitive conclusion. In the second part, we analyzed the Vlasov and Kuramoto kinetic models. To study their infinite dimensional dynamics, we looked at bifurcations around unstable steady states. The goal was to obtain reduced equations describing the dynamical evolution. We performed unstable manifold expansions on five different kinetic systems. These reductions are in general not exact and plagued by singularities, yet they predict correctly the nature and scaling of the bifurcation, which we tested numerically. We conjectured an exact dimensional reduction (obtained using the Triple Zero normal form) around the inhomogeneous states of the Vlasov equation. These results are expected to be very generic and could be relevant in an astrophysical context. Other results apply to synchronization phenomena through the Kuramoto model for oscillators with inertia and/or delayed interactions
Melo, Alba Cristina M. A. "Conception d'un système supportant des modèles de cohérence multiples pour les machines parallèles à mémoire virtuelle partagée." Grenoble INPG, 1996. http://www.theses.fr/1996INPG0108.
Nika, Jérôme. "Guiding Human-Computer Music Improvisation : introducing Authoring and Control with Temporal Scenarios." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066141/document.
This thesis focuses on the introduction of authoring and controls in human-computer music improvisation through the use of temporal scenarios to guide or compose interactive performances, and addresses the dialectic between planning and reactivity in interactive music systems dedicated to improvisation. An interactive system dedicated to music improvisation generates music on the fly, in relation to the musical context of a live performance. We focus here on pulsed and idiomatic music relying on a formalized and temporally structured object, for example a harmonic progression in jazz improvisation. The same way, the models and architecture we developed rely on a formal temporal structure. This thesis thus presents: a music generation model guided by a ''scenario'' introducing anticipatory behaviors; an architecture combining this anticipation with reactivity using mixed static/dynamic scheduling techniques; an audio rendering module to perform live re-injection of captured material in synchrony with a non-metronomic beat; and a framework to compose improvised interactive performances at the ''scenario'' level. This work fully integrated frequent interactions with expert musicians to the iterative design of the models and architectures. These latter are implemented in the interactive music system ImproteK that was used at various occasions during live performances with improvisers. During these collaborations, work sessions were associated to listening sessions and interviews to gather numerous judgments expressed by the musicians in order to validate and refine the scientific and technological choices
Maia, Carlos Andrey. "Identification et commande de systèmes à évènements discrets dans l'algèbre (max,+)." Angers, 2003. http://www.theses.fr/2003ANGE0008.
Timed Event Graphs are a subclass of Petri nets suitable to describe Discrete Event Systems subject to synchronization phenomena. Although these systems have nonlinear time bahavior in conventional algebra they are described by linear equations in dioid algebra. This thesis deals with identification and control problems of such systems. The chapter 3 proposes a parametric estimation method for (max,+)-linear SISO models. The estimation algorithm is developed by assuming the knowledge of the structure of a model represented by an input-output transfer function. The chapter 4 deals with the model-reference control stated in a Just-in-Time context. This approach proposes a control structure based on a precompensator and a feedback controllers which allows to obtain the desired performances for the controlled system. It is shown That this approach always leads to an optimal bahavior of the closed-loop system and that the existence of the optimal controller is independent of the model reference choice (unlike previous approaches found in the literature). These results are used to solve the stabilization problem of timed event graphs
Dumont, Grégory. "Analyse de modèles de population de neurones : cas des neurones à réponse postsynaptique par saut de potentiel." Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14601/document.
This thesis concerns the mathematical modelling and the study of the behavior of a population of neurons. In this work we will mainly consider a population of excitatory neurons whe reall the cells of the network follow the integrate-and-fire model. Nonetheless, we will tackle in a chapter the modelling of an inhibitory population of neurons, and we will discuss in the lastchapter the modelling of a population of neurons that follows the Ermentrout-Koppell model.The point of view of this thesis is given by the population density approach that has beenintroduced more than a decade ago in order to facilitate the simulation of a large assembly ofneurons. More precisely, this approach gives a partial differential equation that describes thedensity of neurons in the state space that is the set of all admissible potential of a neuron. We will assume that when receiving an action potential, the potential of the neuron makes a small jump. As we will see this partial differential equation is non linear (due to the coupling betweenneurons) and non-local (due to the potential jump). If this idea is complicated and abstract, itallows to simulate easily a large neural network.First of all, the thesis gives a mathematical framework for the equations that arise from thisthe population density approach. Then we will discuss the existence and the possible blow upin finite time of the solution. We will discuss how the consideration of more realistic modellingassumptions, as the refractory period and the delay between the emission and the reception ofan action potential can stop the blow up of the solution and give a well posed model.We will also try to caracterise the occurence of synchronization of the neural network. Twodifferent ways of seeing the synchronization will be describe. One relates the blow up in finitetime of the solution to the occurence of a Dirac mass in the firing rate of the population.Nonetheless, taking into account the delays, this kind of blow up will not be observed anymore.Nonetheless, as we will see, with this additional features the model will generate some periodicalsolutions that can also be related to the synchronization of the population
Landry, Tom. "Mesure des trajectoires de patineurs de vitesse courte piste par filtrage particulaire et simulation physique sur tracés paramétriques en vue de l'étude de la performance humaine." Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29263/29263.pdf.
Ossamy, Rodrigue Bertrand. "An algorithmic and computational approach to local computations." Bordeaux 1, 2005. http://www.theses.fr/2005BOR13067.
Coustet, Christophe. "Parallélisation explicite de programmes fonctionnels et synchronisation de processus : application au modèle MaRS." Toulouse, ENSAE, 1993. http://www.theses.fr/1993ESAE0002.
Luçon, Eric. "Oscillateurs couplés, désordre et synchronisation." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://tel.archives-ouvertes.fr/tel-00709998.
Bel, Bernard. "Acquisition et représentation de connaissances en musique." Phd thesis, Aix-Marseille 3, 1990. http://tel.archives-ouvertes.fr/tel-00009692.
Phan, Van Long Em. "Analyse asymptotique de réseaux complexes de systèmes de réaction-diffusion." Thesis, Le Havre, 2015. http://www.theses.fr/2015LEHA0012/document.
The neuron, a fundamental unit in the nervous system, is a point of interest in many scientific disciplines. Thus, there are some mathematical models that describe their behavior by ODE or PDE systems. Many of these models can then be coupled in order to study the behavior of networks, complex systems in which the properties emerge. Firstly, this work presents the main mechanisms governing the neuron behaviour in order to understand the different models. Several models are then presented, including the FitzHugh-Nagumo one, which has a interesting dynamic. The theoretical and numerical study of the asymptotic and transitory dynamics of the aforementioned model is then proposed in the second part of this thesis. From this study, the interaction networks of ODE are built by coupling previously dynamic systems. The study of identical synchronization phenomenon in these networks shows the existence of emergent properties that can be characterized by power laws. In the third part, we focus on the study of the PDE system of FHN. As the previous part, the interaction networks of PDE are studied. We have in this section a theoretical and numerical study. In the theoretical part, we show the existence of the global attractor on the space L2(Ω)nd and give the sufficient conditions for identical synchronization. In the numerical part, we illustrate the synchronization phenomenon, also the general laws of emergence such as the power laws or the patterns formation. The diffusion effect on the synchronization is studied
Pfeuty, Benjamin. "Rôles des synapses électriques dans la synchronisation neuronale : Une étude théorique." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2004. http://tel.archives-ouvertes.fr/tel-00007936.
Aupy, Jérôme. "Rôle du striatum dans la physiopathologie des épilepsies focales : un modèle translationnel de l’Homme au primate non-humain." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0464/document.
Background: Although a number of experimental and clinical studies have pointed out participation or an even more prominent role of basal ganglia in focal seizures, the mode of interaction between cortical and striatal signals remains unclear. In the present thesis, we first we took the opportunity of stereoelectroencephalographic recordings in drug-resistant epilepsy patients, to qualitatively and quantitatively analyse the ictal striatum activity. Secondly, we created a primate model of subcortical focal motor seizures induced by GABAergic antagonist striatal injections First study: Patients and method: eleven patients who underwent SEEG evaluation were prospectively included if they fulfilled two inclusion criteria: i) at least one orthogonal intracerebral electrode contact explored the basal ganglia, in their either putaminal or caudate part, ii) at least two SEEG seizures were recorded. Cortical and subcortical regions of interest were defined and different periods of interest were analysed. SEEG was visually inspected and h2 non-linear correlation analysis performed to study functional connectivity between cortical region of interest and striatum. Results: Two main patterns of striatal activation were recorded: the most frequent was characterised by an early alpha/beta activity that started within the first five second after seizure onset. The second one was characterised by a late slower, theta/delta activity. A significant difference in h2 correlation indexes was observed during the preictal and seizure onset period compared to background for global striatal index, mesio-temporal/striatal index, latero-temporal/striatal index, insular/striatal index, prefrontal/striatal index. In addition, a significant difference in h2 correlation indexes was observed during the seizure termination period compared to all the other periods of interest. Second study: Material and method: Experiments were performed on three fascicularis monkeys. Acute GABAergic antagonist (bicuculine) injections were performed within the sensorimotor part of the striatum. Behavioural modifications were recorded and scored according to a modified Racine’s scale. Electromyography, electroencephalography, basal ganglia local field potentials were recorded during each experiment. A backaveraging analysis was performed for each recorded session. Results: over the 39 Bicuculline injections, 29 (74.3%) produced dramatic reproducible behavioural changes characterised by repetitive and pseudo-periodic myoclonic jerks with generalised tonic-clonic seizures. NaCl injections never produced any behavioural changes. Myoclonic jerks were clearly detectable on the EMG signal as short stereotypical EMG burst concomitant from abnormal epileptic spikes recorded on EEG. Back averaging analysis from EMG myoclonia showed that electrophysiological activity started significantly earlier in the striatum (p < 0.0001), the GPe (p < 0.0003) and the GPi (p < 0.0086) than in the cortex. Conclusion: These changes in synchronisation level between cortical and striatal activity might be part of an endogenous mechanism controlling the duration of abnormal oscillations within the striato-thalamo-cortical loop and thereby their termination. GABAergic fast-spiking interneurones might play a crucial role synchronising the cortico-striato-thalamic network and a drastic GABAergic modification of the striatum can induce focal seizures. The role of the basal ganglia role in strengthening mechanisms underlying cessation of ictal propagation should inspire new rationales for deep brain stimulation in patients with intractable focal epilepsy