Dissertations / Theses on the topic 'Retards de transport'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 16 dissertations / theses for your research on the topic 'Retards de transport.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Pujo-Menjouet, Laurent. "Contribution à l'étude d'une équation de transport à retards décrivant une dynamique de population cellulaire." Phd thesis, Université de Pau et des Pays de l'Adour, 2001. http://tel.archives-ouvertes.fr/tel-00001176.
Nouasse, Houda. "Gestion supervisée de systèmes étendus à retards variables : cas des réseaux hydrographiques." Thesis, Toulouse, INPT, 2015. http://www.theses.fr/2015INPT0001/document.
On either side of the Earth, we observe more and more devastating natural phenomena. Amon these phenomena, floods are one of the most frequent and devastating natural disasters. During these last decades extensive flooding were caused by the flood of rivers. These floods due to excessive rainfall or runoff induce invariably the loss of human lives and material damages. To overcome these problems, water systems are increasingly equipped with means for detecting floods. A key factor in the management of such phenomena is responsiveness. Indeed, managers of river systems, faced to this kind of situation should quickly take important decisions in an uncertain context, as most of these floods are induced by abrupt climate events, whose magnitude is difficult to assess accuracy. We propose in this dissertation, a method of flood management in river systems equipped with flood zones controlled by gravitational gates. At first, we modeled our management method using a static transportation network. In a second step, we enriched it by using transportation networks with delays in order to take into account the travel time of the managed resource. The main difficulty of transportation networks with delays is their oversize. To overcome this problem, we developed an alternative mechanism combining a static reduced transportation network with a temporization matrix. Furthermore, this mechanism allows the consideration of variable time transfer depending on flows, without modification either on the transportation network, or on the structure of the temporization matrix. This mechanism allows simplified management of the transfer times, variable or not. With this mechanism, the evaluation of the minimum cost maximum flow allowed us, according to the management strategies considered, to compute the gate opening for floodplains in order to mitigate the flood but also to restore the water stored at the relevant time. Finally, to evaluate the contributions of this management, the method was applied to a case study based on a section of river equipped with three flood control reservoirs areas modeled using hydraulic simulators combining 1D and 2D models. The simulation results showed that the proposed approach allowed reducing significantly the floods downstream watercourses
RABIN, OLIVIER. "Approches physiologiques et physiopathologiques des transports hematoencephalique : caracterisation et regulation du transport du manganese; alteration du transport des acides amines au cours du retard de croissance intra-uterine." Paris 7, 1992. http://www.theses.fr/1992PA077164.
Cai, Jianru. "Le transport multimodal : étude comparée de droit chinois et de droit français." Thesis, Paris 1, 2018. http://www.theses.fr/2018PA01D048.
No English summary available
Citolleux, Marie-Rose. "La responsabilité du transporteur routier international pour perte, avarie, ou retard selon la convention de Genève du 19 mai 1956 (C. M. R. ) : étude comparée des droits français, allemand, autrichien et suisse." Paris 1, 1996. http://www.theses.fr/1996PA010286.
The study of the application of the CMR convention, 19 may 1956, in France, Germany, Austria and Switzerland concerning the liability of the road carrier for loss, damage or for delay in the delivery, shows that the evolution has been complex. Eventhough the application of the four different countries shows that in general the solution of case law is uniform there remains still less than ten points which are differently interpretated by the courts. Those points concern the determination of the liability as well as the implementation of this liability. The differences of interpretations bring out that the French interpretation is always stronger than that of the other countries and that the carrier sued in front of the French courts will have a less favourable treatment compared to a carrier sued in Germany, Austria or Switzerland
Bezerra, Rufino Ferreira Paiva Eduardo. "Wind Velocity Estimation for Wind Farms." Electronic Thesis or Diss., Université Paris sciences et lettres, 2023. http://www.theses.fr/2023UPSLM046.
This thesis designs algorithms to estimate the wind speed and direction for wind turbines and wind farms.First, we propose data-based methods to estimate the Rotor Effective Wind Speed (REWS) for a single turbine without prior knowledge of certain physical parameters of the turbine that might be unknown to an operator.We provide two data-based methods, based respectively on Gaussian Process Regression (GPR) and on an combination of GPR with high-gain observers.Second, grounding on this REWS estimation at the local level of one turbine, we address the question of estimating the free-flow wind at the level of a wind farm.We start by focusing on wind speed estimation, for a given known wind direction. For a wind farm with a simple geometry, we prove that a local speed measurement disturbed by the presence of the turbines can be used to estimate the free-flow wind speed. We ground our estimation methodology on a simplified wake model, which consists of first-order hyperbolic partial differential equations, the transport speed of which is the free-flow wind speed. We propose to use an analytical solution of these equations, involving transport delays, to perform an estimate of the local measurement and to update the free-flow wind speed estimate. We formally prove the convergence of this estimate and numerically illustrate the efficiency of this method.Finally, we move to a more general setup where both the free-flow wind speed and direction are unknown. We propose to use a two-dimensional wake model and to rely on an optimization-based method. This identification problem reveals to be particularly challenging due to the appearance of transport delays, but we illustrate how to circumvent this issue by considering an average value of the free flow wind speed history. Simulation results obtained with the simulator FAST.Farm illustrate the interest of the proposed method
Wang, Chunan. "Essays on Delay Reduction Contract, Airline Networks and Agricultural Land Marketization." Thesis, Toulouse 1, 2017. http://www.theses.fr/2017TOU10024/document.
This thesis consists of three self-contained papers, each of which corresponds to one chapter. The first chapter, jointly written with Estelle Malavolti, studies the optimal design of delay reduction contract signed between an ANSP and a monopoly airline. In the contract design, we mainly consider the adverse selection problem. Moreover, we conduct comparative-static analysis to study the effects of safety standard and flight frequency on optimal contracts. Besides, we use numerical examples to study when a welfare-maximizing ANSP has to use public funds to provide the service. The second chapter investigates the dual roles of congestion delays and horizontal product differentiation in airline network choice. I find that, first, because of the inclusion of congestion delays, the airline may choose the point-to-point network even when the extra travel time disutility of one-stop services is relatively low. Second, without considering the airline's fixed investments of developing a hub airport, the 2-hub network will dominate the three other network structures as long as it is feasible, as it involves the horizontal product differentiation in more markets than the three other network structures. The third chapter, jointly written with Wanjun Yao and Shigeyuki Hamori, empirically finds that the higher land allocation efficiency improves the average land productivity by 29.1% and the larger average operational farm size reduces the average land productivity by 9.2%, implying that the agricultural land marketization in China finally improves the average land productivity by 19.9%
Godoy, Vanessa Almeida de. "Upscaling of water flow and mass transport in a tropical soil: numerical, laboratory and field studies." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-13072018-092153/.
Modelos numéricos estão se tornando ferramentas fundamentais para prever uma série de problemas complexos enfrentados por engenheiros geotécnicos e geoambientais. No entanto, para que o modelo seja confiável para previsões futuras, seus parâmetros de entrada devem ser determinados com a consideração do efeito da escala. Se há uma diferença de escalas entre a escala da observação e a escala do modelo, existem duas maneiras possíveis de considerá-la: ou constrói-se modelos com elementos de tamanhos semelhantes àqueles em que os dados foram medidos, ou definem-se algumas regras de mudança de escala. Neste contexto, esta tese enfoca a mudança de escala do fluxo de água e do transporte de massa em um solo tropical, por meio de estudos numéricos, laboratoriais e de campo. Esta tese é organizada em quatro partes. Em primeiro lugar, estudou-se em detalhe a heterogeneidade, a correlação e a correlação cruzada entre os parâmetros de transporte de soluto (dispersividade, α, e coeficiente de partição, Kd) e as propriedades do solo. Nesta parte, verificou-se que a condutividade hidráulica (K) e os parâmetros de transporte de soluto são altamente heterogêneos, enquanto as propriedades do solo não o são. A correlação espacial de α, K e das variáveis estatisticamente significativas foi estudada, e, provavelmente, melhoraria a estimativa apenas em um estudo em pequena escala, uma vez que a correlação espacial só foi observada até 2,5 m. Este estudo foi uma primeira tentativa de avaliar a variação espacial no coeficiente de correlação dos parâmetros de transporte de um soluto reativo e não-reativo, indicando as variáveis mais relevantes e as que devem ser incluídas em estudos futuros. Na segunda parte, o efeito de escala em K, na dispersividade e no coeficiente de partição de potássio e cloreto é estudado experimentalmente por meio de ensaios laboratoriais e de campo. O objetivo foi contribuir com a discussão sobre os efeitos de escala em K, α e Kd e entender como esses parâmetros se comportam com a mudança na escala da medição. Os resultados mostram que K aumenta com a escala, independentemente do método de medição. A dispersão tende a aumentar de maneira exponencial com a altura da amostra. O coeficiente de partição tende a aumentar tanto com o comprimento, quanto com o diâmetro e o volume da amostra. Essas diferenças nos parâmetros de acordo com a escala de medida devem ser consideradas quando essas observações são posteriormente usadas como entrada para modelos numéricos, caso contrário, as respostas podem ser mal representadas. Em terceiro lugar, uma análise estocástica tridimensional da mudança de escala da condutividade hidráulica foi realizada usando tanto média simples quanto o método Laplaciano-com-pele para vários tamanhos de blocos usando medidas K reais. Nesta parte, foram demonstrados os erros que podem ser introduzidos ao se usar métodos determinísticos de mudança de escala, usando médias simples das medições de K sem se considerar a correlação espacial. A aplicação das técnicas de mudança de escala mostra que a heterogeneidade de K pode ser incorporada na prática diária do modelador geotécnico. Os aspectos a serem considerados ao realizar a mudança de escala também foram discutidos. Finalmente, analisou-se a dependência do expoente da norma p em função do tamanho do bloco. Na última parte, uma aplicação de mudança de escala estocástica do coeficiente de dispersão hidrodinâmica (D) e do fator de retardo (R) foi realizada usando dados reais visando reduzir a falta pesquisas no tema de mudança de escala do transporte de soluto reativo. A mudança de escala do D foi feito usando o método de macrodispersão. O método da média simples baseado na norma p foi usado para executar a mudança de escala de R. A incerteza foi propagada satisfatoriamente. Métodos simples de mudança de escala podem ser incorporados à prática de modelagem usando programas comerciais, e reproduzir corretamente o transporte em escala grossa, mas podem exigir correções para reduzir o efeito suavizado da heterogeneidade causada pelo procedimento de mudança de escala.
Letrouit, Vincent. "Optimisation du réseau des routes aériennes en Europe." Grenoble INPG, 1998. http://www.theses.fr/1998INPG0141.
Zamoum, Redouane. "Etude théorique des fluctuations de courant de l'admittance et de la densité d'états d'un nano-système en interaction." Phd thesis, Aix-Marseille Université, 2013. http://tel.archives-ouvertes.fr/tel-00881571.
Benboubker-Jebbari, Samira. "Risque, sécurité et responsabilité du transporteur aérien à l'égard de son passager." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05D004.
In recent decades, air transport has been greatly democratized, the regulations has increased significantly. The applicable sources for the air carrier liability are based on international conventions, EU regulations and domestic legislations. This research points dynamic application of the sources and the results produced by different combinations. The evolution of the responsibility concept starts other fields of thought through a combined study of the concepts of risk and safety of air carrier towards passengers. It's also studying the particularism of the carriage contract by air of persons under new regards. EU law has brought a new vision of the carriage contract to the point that it assimilates the passenger to a consumer. The liability of the air carrier also values the new technologies field. Today, air passenger benefits from protective measures of consumer law. The damage analysis helps to understand this nesting process sources, and the diversity of cases law. EU law has set up an innovative and pragmatic regulation in line with new requirements on passenger delays and flight cancellations. The purpose is showing the important role of EU law in the cumulative application of treaty law and of Regulation No 261/2004. The general notion of delay has to be dissociated from ordinary situations generating delay; EU law has drawn a distinction between these events. The delay may be experienced collectively by the passengers, as in case of flight cancellation or individually as in case of denied boarding. EU law enacted standardized measures of assistance and compensation. These mechanisms should be explained such as the improvements proposed by the European legislator. In case of accidents the air carrier liability puts the Convention at the center of attention. Exclusivity agreements are more than ever reasserted by international jurisprudence. However this elevation of treaty law is undermined by some courts practices, which do not hesitate to put aside the Convention to the benefit of the domestic law. Dismantling risk of conventional law is softened by the different references of EU law and domestic law to the primacy of the Convention. The air carrier's liability is a strict liability. It puts an end to any financial limitations in case of body injury or death of passenger. The lack of definition of accident concept continues to raise many questions. For accidents, treaty law carries out an implicit reference to domestic law in order to determine the positions damages. As part of the complementarity of sources, it is important to have a combined approach of French domestic law, which enshrines the principle of full compensation, and the enforcement of treaty law. Air passenger travels with his personal effects. Treaty law has introduced different liability regimes depending on luggage destination. The provision of EU law is minimalist in terms of luggage, but the CJUE cases law allowed a renewed interpretation of the compensation for luggage damages. The study of this liability will lead us to stress the importance of IATA regulations and general terms of carriage which fill in the gaps in EU and treaty law, not interested in this part of the air carrier's liability. The Convention has established options of competence which lead to a multitude of courts. The advent of fifth option of competence is part of a consumerist approach of treaty/conventionnal law. More ground of jurisdiction are, more important is the practice of forum shopping. Jurisdiction rules have been enacted by the jurisprudence as mandatory. The introduction of standardized measures of assistance and compensation by EU law highlighted the purview of exclusive nature of the jurisdiction rules. A liability action of victims in case of aircraft accidents or their heirs before the U.S. courts is likely to result in a forum non conveniens. A survey of American and French jurisprudence is needed to measure the extent of this phenomenon. (...)
Böhm, Julian. "Phénomènes de transport originaux dans des expériences micro-ondes via la mise en forme spatiale et spectrale." Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4048/document.
Transport of waves plays an important role in modern communication systems like Wi-Fi or optical fibres. Typical problems in such systems concern security against possible intruders, energy consumption, time efficiency and the possibility of mode filtering. Microwave experiments are suited to study this kind of problems, because they offer a good control of the experimental parameters. Thus we can implement the method of wave shaping to investigate atypical transport phenomena, which address the mentioned problems. Wave front shaping solely based on the transmission together with the Wigner-Smith time delay formalism allows me to establish special scattering states in situ. These scattering states avoid a pre-selected region, focus on a specific spot or follow trajectories of classical particles, so called particle-like scattering states. Mode filtering is induced inside a waveguide with wavy boundaries and position dependent loss. The boundary profiles are chosen in such a way that the two propagating modes describe an encircling of an exceptional point in the Bloch picture. The asymmetric mode filtering is found due to the appearing non-adiabatic transitions. Another part of my work deals with Grover’s quantum search. I put such a search into practice in a two-dimensional graphene-lattice using coupled resonators, which form a tight-binding analogue. In this proof of principle experiment we search for different resonators attached to the graphene-lattice. Furthermore, the scaling behaviour of the quantum search is quantified for a linear chain of resonators
Richard, Quentin. "Comportement asymptotique de modèles de populations structurées." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCD050/document.
This thesis is dedicated to some structured populations models described with transport or transport-diffusion equations. The well-posedness, in the semigroupes setting in L1 and the positivity of the solutions are systematically shown. A first work is dedicated to an age-structured predator/prey system. A stability study of the equilibria allow us to give explicit formulations of an extinction threshold and an threshold which can lead to explosion of solutions. We numerically obtain the possibility to get a limit cycle and the convergence to a coexistence equilibrium of the populations. In a specific case, this model rewrites as a delay differential system. Using Lyapunov functional, we show the global stability of this equilibrium under some assumptions. We also study two size-structured models that come from cellular dynamics. The first one consists on two transport equations, where the cell can either proliferate or be quiescent, and the second one is a transport-diffusion equation with Feller boundary conditions. The irreducibility of the semigroup governing this latter model is always satisfied using the Hopf maximum principle. However, the irreducibility for the first model is true only under a necessary and sufficient condition that we give. We also show for these two models, using some weak compactness arguments in L1, the existence of a `spectral gap' (essential type strictly less than the type) ensuring the asynchronous exponential growth of the semigroup
Bielinski, Clément. "Impact of the flow on mass transfer from particles : biomedical applications." Thesis, Compiègne, 2021. https://bibliotheque.utc.fr/Default/doc/SYRACUSE/2021COMP2630.
Mass transfer from particles is encountered in many biomedical applications, such as controlled drug delivery, cell culture, or in designing bioartificial organs. In operating conditions, particles are subjected to various flows, whose effect on solute transport is still not well understood and controlled. In this PhD thesis, we study the effect of the flow on mass transfer from core-shell capsules and fibers, using numerical simulations. Solute release from a core-shell fiber confined in a channel and subjected to Poiseuille flow is studied using two-dimensional lattice Boltzmann simulations. The combined effects of the flow and the shell permeability on mass transfer are analyzed over a wide range of Reynolds number covering both steady and unsteady flows. A new correlation giving the Sherwood number (the dimensionless mass transfer coefficient) as a function of the shell permeability, the Reynolds number, and the Schmidt number is proposed. The shell permeability is difficult to measure. Current characterization methods only allow the determination of an effective permeability for the whole particle (core and shell combined), and not specifically the shell permeability. A novel method to characterize capsules shell permeability is proposed and validated on both numerical and experimental data. This method consists in extracting the capsule permeability by fitting the release curves with numerical solutions of Fick’s second law of diffusion computed in one dimension using the finite difference method, by assuming spherical symmetry. Solute release from a capsule placed in a shear flow is also analyzed by the mean of three-dimensional simulations coupling the lattice Boltzmann method and the immersedboundary method for the fluid-structure interaction. The flow is found to enhance the masstransfer efficiency by forced convection. The effect of the boundary conditions set at the surface of the capsule is examined, as well. Considering Dirichlet boundary conditions at the particle surface, as classically done in literature, leads to significantly higher Sherwood numbers as compared to the case of continuity of both the concentration and the mass flux, which is more adapted to model solute release. The suspension dynamics of soft capsules in a microfluidic constriction is also studied. A state diagram describing the transition from capsule passage to blockage is determined as a function of their geometrical and mechanical properties. It can be used, for example, to optimize the design of microfluidic devices in order to enhance the mass transfer efficiency
Laurain, Thomas. "Synthèse de contrôleurs avancés pour les systèmes quasi-LPV appliqués au contrôle de moteurs automobiles." Thesis, Valenciennes, 2017. http://www.theses.fr/2017VALE0033/document.
My PhD in Automatic Control is part of the research theme “Transport” of the LAMIH. The objective is to improve the functioning of the gasoline engines, mainly by reducing the fuel consumption and the pollution. With this ecologic and economic challenge, and taking into account the new norms and the short-term strategies of the industry (scandal of Volkswagen...), new controllers have to be designed to control the air valve and the fuel injection inside the engine. Considering the highly nonlinear aspect of the system, the Takagi-Sugeno representation and the theoretical background of the LAMIH have been used. A first controller is designed to solve the problem of idle engine speed. However, the complexity of the system forces the use of a controller that is very costly from a computational point of view. An alternative controller is then designed in order to be implemented inside the embedded computer of the engine. A second controller is obtained to maintain the air-fuel ratio in stoichiometric proportions in order to reduce the pollution. This system being subject to a variable transport delay, a change of domain is realized to make this delay constant, and to design a simple and efficient controller. Real-time experiments have been realized on the engine test bench of the LAMIH in order to validate the presented methodology
Uzunova, Milka. "Commande non-entière des systèmes. : développement et application pour les modèles du flux de trafic routier." Thesis, Artois, 2009. http://www.theses.fr/2009ARTO0205/document.
This thesis presents research carried out to several elements of the macroscopic traffic flow as the model, the control and the simulation of his control system. The main aims of the realized studies consist to keep the circulation on the high-ways fluid. That means that we must to assure some quality of the process regarding the stability of this process. More over to offer best performances and quality of the traffic services for the users on the ways networks.In our study we use the analytical solution method of the dynamic equation presenting the LWR traffic flow model process, for which we look to obtain transfer function. Our objective is to obtain a conform result to a toll plaza. Furthermore we look to make a choice of appropriate control algorithm to satisfy the traffic network and users’ needs. The traffic flow management needs results from the increasingly of the flows. As consequence of this we can obtain saturation in some places in the road network wildly known as a traffic jam usually in the rush hours, by reason of accident or repairs works. All this provoke a delay of the transportation flow and important environmental after-effect. Therefore it’s very important to assure the fluidity of the traffic using control strategies which will cancel, reduce or delay the traffic jam appearances. Because of all the reasons above, we have proposed a system with non-integer order control algorithm for maintain the traffic fluid by the control of the pikes in the toll plaza. The control variable is the upstream density which will influence on the downstream one. After the analytical solution of the toll plaza model we obtain a delay function which presents the plant in our distributed parameter system. For this system we apply a Smith prediction non-integer control algorithm and moreover we ameliorate this system with a Dead time non-integer order compensator