Дисертації з теми "Modèle différentiable"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-15 дисертацій для дослідження на тему "Modèle différentiable".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Fauthoux, David. "Des grains aux aspects, proposition pour un modèle de programmation orientée-aspect." Toulouse 3, 2004. http://www.theses.fr/2004TOU30100.
Current programming technologies do not able to clearly separate crosscutting concerns. The code of a concern is scattered into the program components. After having detailed and analysed four main aspect-oriented systems, this report presents a fine-grained model. These grains, the "lenses", are grouped to create more abstract components. The first step of the report describes a "flow" as a chain of lenses. A program can be defined as a set of intersecting flows. The second step of the report comes to the "aspect" concept, applied onto specified points of the program. These abstract groups (flows and aspects) are exactly shaped like lenses. Thus the model is consistent from the bottom level (classes) to the more abstract ones (groups, and groups of groups). The main goal of this report is to enable to express as brightly as possible the structure of the program. The model walks on the way which aims at splitting the program architecture building phase from the component writing phase. Architect is a job which requires composition skills and tools. It is to be separated from the developer job which uses and manipulates the program language to write components
Gavagsaz, Ghoachani Roghayeh. "Comportement dynamique non-linéaire dans les convertisseurs statiques : régulateurs de courant et stabilité des réseaux DC." Electronic Thesis or Diss., Université de Lorraine, 2012. http://www.theses.fr/2012LORR0102.
This thesis discusses the study of dynamic behavior in power electronics systems. The nature of cycles defined by the state variables of the system can be settled either by a bifurcation diagram or by Floquet multipliers obtained from the discrete model of the converter. However, for certain structures of static converters, a discrete model cannot be obtained without introducing large assumptions. The flip bifurcations (fast-scale) cannot be predicted by the averaged model whereas they appear in many statics converters. A new formulation of a continuous averaged model is presented to estimate the first bifurcation point (flip, Hopf ...). The proposed methodology is applied to a boost converter, operated in continuous conduction mode, controlled by different types of fixed frequency switching current controllers. Then, this averaged model is used for the design of the current controller parameters associated with an active filter system. The variables obtained by the proposed model have been validated by numerical simulation and experimental results. Methods of analysis of limit cycles are extended to study the stability of DC networks when the cutoff frequency of the LC filter between the voltage source and the converter is close to the switching frequency of converters. Different discrete-time models have been developed in order to consider whether to use sampled or no-sampled converter control
Baldi, Guillaume. "Contributions à la modélisation procédurale de structures cellulaires stochastoques 2D et à leur génération par l'exemple." Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAD001.
The creation of procedural materials and textures requires considerable expertise, and is time-consuming, tedious and costly. We are therefore looking to develop tools for the automatic generation of procedural textures and materials from input exemplars provided in the form of images: This is known as inverse procedural modeling.In this thesis, we propose a procedural model called Cellular Point Process Texture Basis Function (C-PPTBF) for representing 2D stochastic cellular structures, involving functions that are differentiable with respect to most of their parameters, making it possible to estimate these parameters from examples without resorting entirely to deep neural networks. We have set up a processing pipeline to estimate the parameters of our model from structural examples provided in the form of binary images, combining an estimation performed using a convolutional neural network trained on images produced with our C-PPTBF model and an estimation phase using gradient descent directly on the parameters of the procedural model
Ndiaye, Ismaïla Abderhamane. "Résolution de problèmes multicritères (durée/sécurité) pour la conception de plans d'évacuation de personnes." Thesis, Tours, 2016. http://www.theses.fr/2016TOUR4001/document.
The work presented in this thesis aims to propose methods for routing a mass population through a disturbed network whose data vary over time. This problem can be illustrated by disasters due to humans or natural events where people (potentially) affected have to leave their living places for a period of one to several days. In the literature, mass routing are often modeled as dynamic flow problems whose objective is to minimize the overall duration of the evacuation process from a set of gathering points towards another set of shelter locations. However few papers take into account the concept of safety during this routing nor deploying task forces that can secure or facilitate this process. In this context, the safety security can be seen as a danger affecting the quality of life of people we organize the trip. In this context, the safety can be seen as a danger that influence the health of the people we are trying to evacuate. Indeed, this hazardous event can be related to a radioactive cloud, a fire, a tsunami, an earthquake or a flooding which make some of paths becoming dangerous or less usable by evacuees
Cellier, Dominique. "Deux extensions des résultats classiques sur les estimateurs à rétrécisseur : cas de rétrécisseurs non différentiables ; cas de lois à symétrie sphérique." Rouen, 1986. http://www.theses.fr/1986ROUES044.
Dkhil, Fathi. "Analyse de systèmes de réaction-diffusion-advection apparaissant dans des modèles de chimie et de biomathématiques." Cergy-Pontoise, 2002. http://www.theses.fr/2002CERG0143.
In this work, we study some examples of reaction-diffusion-advection systems which appear in models of physics, chemistry and biology. In the first, part we study the Gray-Scott system, which modelizes a cubic autocatalytic reaction. We first establish the global existence and uniqueness of a non trivial solution of this system in a bounded domain. We also prove the non-existence of non-constant stationary solution and of traveling pulse for some domain of parameters. As for traveling waves we first give an exact solution in the bistable case. Using a perturbation method and a fixed point argument, we show that this solution still exists near this case. In the second part we are interested in traveling wave solutions of a cross-diffusion system modelizing a combustion phenomenon in a porous medium. Using the topological degree method, we show the existence of a solution of the problem in a bounded domain. Then, by a compactness argument, we show that the solution obtained this way converges to a solution of the limit problem over on the line. In the last part, we study the singular limit of a degenerate reaction-diffusion-advection equation modelizing a chemotaxis phenomenon. We prove the convergence to a solution of a free boundary problem where the equation of the interface motion is a first-order Hamilton-Jacobi equation. The proof is based on the comparison principle and on the construction of sub- and super-solutions
Gavagsaz, Ghoachani Roghayeh. "Comportement dynamique non-linéaire dans les convertisseurs statiques : régulateurs de courant et stabilité des réseaux DC." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0102/document.
This thesis discusses the study of dynamic behavior in power electronics systems. The nature of cycles defined by the state variables of the system can be settled either by a bifurcation diagram or by Floquet multipliers obtained from the discrete model of the converter. However, for certain structures of static converters, a discrete model cannot be obtained without introducing large assumptions. The flip bifurcations (fast-scale) cannot be predicted by the averaged model whereas they appear in many statics converters. A new formulation of a continuous averaged model is presented to estimate the first bifurcation point (flip, Hopf ...). The proposed methodology is applied to a boost converter, operated in continuous conduction mode, controlled by different types of fixed frequency switching current controllers. Then, this averaged model is used for the design of the current controller parameters associated with an active filter system. The variables obtained by the proposed model have been validated by numerical simulation and experimental results. Methods of analysis of limit cycles are extended to study the stability of DC networks when the cutoff frequency of the LC filter between the voltage source and the converter is close to the switching frequency of converters. Different discrete-time models have been developed in order to consider whether to use sampled or no-sampled converter control
Fourdrinier, Dominique. "Deux extensions des résultats classiques sur les estimateurs à rétrécisseur : cas de rétrécisseurs non différentiables ; cas de lois à symétrie sphérique." Rouen, 1986. http://www.theses.fr/1986ROUES043.
Barbaroux, Cécile. "Analyse et modélisation des flux de carbone de peuplements forestiers pour la compréhension de la croissance de deux espèces feuillues Quercus petraea et Fagus sylvatica." Paris 11, 2002. http://www.theses.fr/2002PA112084.
Several dendroecological studies (inter-annual variations of the tree-rings width according to the climate) of the sessile oak (ring porous species) and of the beech (diffuse porous species) put into evidence their interrelationships with the climatic signal of the year and differed effects of the climate or the growth. These differed effects are often more obvious and older on oaks. Our objectives are to verify if the anatomies and/or the contrasted phenology (setting up of leaves, resuming of wood growth) of these two species entail a different management of carbohydrate reserves, and of specific carbon allocation pattern, at intra- and in inter-annual scales. To reach these objectives, we have developed a pluridisciplinary approach associating dendrochronology, ecophysiology, dendrometry and modeling of water and carbon functioning of oaks and beeches stands. The analysis of the inter-annual variations of radial growth of the oak and of the beech was based on the last 30 years measurements on 900 varied trees in terms of fertility and age in the Fontainebleau forest. Dendroclimatic study puts into evidence a strong dependence of the beeches stands productivity on the soil water availability during the season of vegetation of the year and the previous year. For oaks stands, the productivity is correlated to the soil water availability during the season of vegetation and to the growth of the previous year. The biochemical analysis of carbohydrate reserves (starch, sucrose, glucose and fructose), made on two pure stands of oaks and beeches of 35 years old in Lorraine, reveals a seasonal dynamics of reserves more obvious as well as an higher concentration for the oak. These differences of reserve management correspond to the important needs in growth of the oak during the phase of carbon heterotrophy. Analyzing the reserves quantities and yearly growth in biomass of the population on several years required preliminary works to describe intra- and inter-trees variability and then to up-scale the studied tree to the stand. Knowledge acquired on the seasonal dynamics of carbohydrate reserves quantities, as well as on the growth phenology of the oak and the beech, have been integrated in a model of stand carbon balance (CASTANEA, E. Dufrêne). The possible changes of carbon allocation to the growth between years can be tested thanks to the model, through hypotheses of interactions between dynamics appropriate in reserves and growth. These modifications have been tested on the Fontainebleau site. .
Petrou, Georgios. "Dimensionnement robuste des réseaux de télécommunication face à l'incertitude de la demande." Paris 1, 2008. http://www.theses.fr/2008PA010037.
Lagasquie, Gabriel. "Etude du comportement en temps long de processus de markov déterministes par morceaux." Thesis, Tours, 2018. http://www.theses.fr/2018TOUR4004/document.
The objective of this thesis is to study the long time behaviour of some piecewise deterministic Markov processes (PDMP). The flow followed by the spatial component of these processes switches randomly between several flow converging towards an equilibrium point (not necessarily the same for each flow). We will first give an example of such a process built in the plan from two linear stable differential equations and we will see that its stability depends strongly on the switching times. The second part of this thesis is dedicated to the study and comparison of two competition models in a heterogeneous environment. The first model is a probabilistic model where we build a PDMP simulating the effect of the temporal heterogeneity of an environment over the species in competition. Its study uses classical tools in this field. The second model is a deterministic model simulating the effect of the spatial heterogeneity of an environment over the same species. Despite the fact that the nature of the two models is very different, we will see that their long time behavior is very similar. We define for both model several quantities called invasion rates modelizing the growth (or decreasing) rate speed of a species when it is near to extinction and we will see that the signs of these invasion rates fully describes the long time behavior for both systems
Mahaman, Moutari Mahaman Salissou. "Modélisation mathématique et numérique du trafic automobile." Nice, 2007. http://www.theses.fr/2007NICE4088.
In order to simulate in a relevant way vehicular traffic on large road networks, an essential ingredient is using theoretical tools which allow for an adequate modelling of each component of the network. To achieve this goal, several modelling methods exist to date. However, due to some additional constraints, in particular those related to the development of the road networks infrastructures and the increasing concentration of traffic, the investigation of new modelling tools is necessary. In this work, we have introduced some methods and models, which enable a relevant description of the traffic on road networks, by taking into account its specificity through some particular components of the network such as intersections, highway on and off ramps, toll stations, etc…. The presented approaches are expected to be theoretically rigorous, numerically reliable, and computationally efficient. The first approach we have proposed concerns macroscopic models. It is based on the resolution of the Riemann problem whereas the flux at the junction is optimized. Thereafter we have extended this approach to macroscopic multiclass models. The second approach studied in this work is the hybrid modelling. First, we have proposed a hybrid model based on the classical Eulerian-Lagrangian coupling of the Aw & Rascle second order macroscopic model and a class of microscopic models. In a such hybrid model, the interfaces between the coupled models are fixed in eulerian coordinates. Thereby, the interfaces’ functioning is somehow complex and tedious to work out. In order to circumvent this problem, we have proposed a fully lagrangian coupling approach. The novelty of this new hybrid approach is that the interfaces are moving in lagrangian coordinates. This particular property makes the model much simpler than in the previous case and leads to a rigorous and easy computational model. Finally we have proposed a model describing the formation and evolution of traffic jams. This model is derived from the Aw & Rascle second order macroscopic model and based on a realistic formulation of clusters dynamics. We have analysed the solutions to the associated Riemann problem and we have proved the existence of solutions for this model
Bahoken, Françoise. "Contribution à la cartographie d’une matrice de flux." Sorbonne Paris Cité, 2016. https://hal-univ-diderot.archives-ouvertes.fr/tel-01273776/document.
Mapping a flow matrice aims to project its values on a map, using linear and punctual features as a graph, but depicting generally geographical patterns. When the study area is large, this approach leads several difficulties, graphics constraints and challenges that must be addressed. This thesis offers four families of contributions for reducing analytical and graphical complexity of flow mapping, the so-called spaghetti¬effect. Firstly, by proposing a formalization of the complexity components and a typology of the usual flow mapping process. Then, on both theoretical and conceptuel levels, by establishing the different logics underlying flow mapping ; also the meaning of the flow map compared to the map of movements, then introducing the geographical area in the flow mapping process (not in its modeling step). Then, methodologically, by mobilizing in one hand, only graphical aspects in order to renew the cartographic semiotics of flows and, on the other hand, the flow data in the context of discussions about the choice of the selection criteria, as they consider geographical space (distance, neighborhood,. . . ) or not, as they are global, focused on flows or on spaces. The approach wanting to be general and generalizable, the proposed solutions are empirically validated on migration or trade flow matrices that are expressed at different geographical scales, from local to global levels
Chajmowicz, Henri. "Modélisation et simulation numérique de structures articulées flexibles." Phd thesis, Marne-la-vallée, ENPC, 1996. http://pastel.archives-ouvertes.fr/pastel-00569038.
Da, Silva De Aguiar Raquel Stella. "Optimization-based design of structured LTI controllers for uncertain and infinite-dimensional systems." Thesis, Toulouse, ISAE, 2018. http://www.theses.fr/2018ESAE0020/document.
Non-smooth optimization techniques help solving difficult engineering problems that would be unsolvable otherwise. Among them, control problems with multiple models or with constraints regarding the structure of the controller. The thesis objectives consist in the exploitation, specialization and development of non smooth optmization techniques and tools for solving engineering problems that are not satisfactorily solved to the present