Dissertations / Theses on the topic 'Optimisation de concepts multidisciplinaires'
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Saves, Paul. "High dimensional multidisciplinary design optimization for eco-design aircraft." Electronic Thesis or Diss., Toulouse, ISAE, 2024. http://www.theses.fr/2024ESAE0002.
Nowadays, there has been significant and growing interest in improving the efficiency of vehicle design processes through the development of tools and techniques in the field of multidisciplinary design optimization (MDO). In fact, when optimizing both the aerodynamics and structures, one needs to consider the effect of the aerodynamic shape variables and structural sizing variables on the weight which also affects the fuel consumption. MDO arises as a powerful tool that can perform this trade-off automatically. The objective of the Ph. D project is to propose an efficient approach for solving an aero-structural wing optimization process at the conceptual design level. The latter is formulated as a constrained optimization problem that involves a large number of design variables (typically 700 variables). The targeted optimization approach is based on a sequential enrichment (typically efficient global optimization (EGO)), using an adaptive surrogate model. Kriging surrogate models are one of the most widely used in engineering problems to substitute time-consuming high fidelity models. EGO is a heuristic method, designed for the solution of global optimization problems that has performed well in terms of quality of the solution computed. However, like any other method for global optimization, EGO suffers from the curse of dimensionality, meaning that its performance is satisfactory on lower dimensional problems, but deteriorates as the dimensionality of the optimization search space increases. For realistic aircraft wing design problems, the typical size of the design variables exceeds 700 and, thus, trying to solve directly the problems using EGO is ruled out. In practical test cases, high dimensional MDO problems may possess a lower intrinsic dimensionality, which can be exploited for optimization. In this context, a feature mapping can then be used to map the original high dimensional design variable onto a sufficiently small design space. Most of the existing approaches in the literature use random linear mapping to reduce the dimension, sometimes active learning is used to build this linear embedding. Generalizations to non-linear subspaces are also proposed using the so-called variational autoencoder. For instance, a composition of Gaussian processes (GP), referred as deep GP, can be very useful. In this PhD thesis, we will investigate efficient parameterization tools to significantly reduce the number of design variables by using active learning technics. An extension of the method could be also proposed to handle mixed continuous and categorical inputs using some previous works on low dimensional problems. Practical implementations within the OpenMDAO framework (an open source MDO framework developed by NASA) are expected
Othmani, Imed. "Optimisation multicritère : fondements et concepts." Phd thesis, Université Joseph Fourier (Grenoble), 1998. http://tel.archives-ouvertes.fr/tel-00004900.
Ooi, Beng Lee. "Optimisation and frequency tuning concepts for a vibration energy harvester." Thesis, University of Hull, 2010. http://hydra.hull.ac.uk/resources/hull:4472.
Vilardaga, García-Cascón Santi. "An integrated framework for trajectory optimisation, prediction and parameter estimation for advanced aircraft separation concepts." Doctoral thesis, Universitat Politècnica de Catalunya, 2019. http://hdl.handle.net/10803/668090.
Des del naixement de l’aviació comercial, les aplicacions i beneficis dels avions han crescut immensament. Això, en perfecta sincronia amb l’augment mitjà del poder adquisitiu de la societat, ha augmentat el nombre d’avions que volen pel cel. Aquest augment comporta, tanmateix, un cost, tant en aspectes mediambientals com en la capacitat de l’espai aeri. Aquesta tesi és concebuda per treballar en l’alleujament dels problemes que resulten de l’elevat nombre de vols, proposant nous conceptes i mecanismes per augmentar la capacitat de l’espai aeri amb seguretat i alhora minimitzar l’impacte ambiental de l’aviació. Aquesta recerca, complexa però extremadament necessària, és la protagonista d’una gran quantitat de treballs científics publicats. Des de la propulsió, fins a les aerostructures i la gestió del transit aeri, avui en dia es dedica un gran esforç a la reducció de l’impacte ambiental, així com a l’augment de la seguretat i la capacitat de l’espai aeri. Un tema prometedor és la introducció de nous conceptes d’operació que aprofiten al màxim l’optimització de trajectòries en les quatre dimensions (4D) i nivells d’automatització més elevats, tant per a sistemes de bord com de terra. Conceptes com ara operacions de perfil vertical continu són cada cop més utilitzats en el dia a dia. També, la reducció de la distancia recorreguda dels avions mitjançant rutes més directes esdevé una realitat com més va més evident. Per tal d’abastar un àmbit més ampli, els sistemes embarcats i de terra hauran d’esser actualitzats. És per això que s’hauria d’explorar minuciosament la quantificació dels beneficis esperats per als nou conceptes que es proposin, abans d’introduir-los a escala local o global. La investigació d’aquesta tesi doctoral proposa un sistema integrat per a l’optimització de trajectòries, la predicció, i l’estimació de paràmetres, amb el qual es poden avaluar nous conceptes de gestió del trànsit aeri. Aquest sistema té la flexibilitat d’optimitzar trajectòries que van des d’un vol lliure (free-flight) fins a una estructura de ruta molt estricta, des d’una llibertat completa al perfil vertical fins a una adhesió especifica als nivells de vol, etc. La definició d’escenaris és prou genèrica com per permetre una àmplia varietat de tipologies de vol, fases de vol, fases de rendiment, restriccions al llarg de la trajectòria, entre molts altres aspectes. L’estratègia d’optimització 4D d´ona com a resultat una trajectòria que no només compleix les característiques del vol (i de l’entorn configurat), sinó que també minimitza un objectiu funcional determinat, com ara el cost operatiu, el temps, el combustible, etc. I com ja s’ha mencionat breument, aquesta mateixa estratègia d’optimització s’adapta lleugerament per presentar una innovadora estratègia per realitzar prediccions de trajectòria adaptativa (amb monitoratge de conformitat) i per estimar paràmetres crucials inicialment desconeguts d’un avió. Per resoldre un problema tan complex, es formula un problema de control òptim i es converteix en un problema de programació no lineal (NLP) amb mètodes de col·locació directa. Aquest problema es resol numèricament mitjançant un programari de resolució de problemes NLP i se n’extreuen els resultats per a l’anàlisi. Es presenta una arquitectura de programari integral, aprofitant el millor de dos mons: un llenguatge de programació orientat a objectes (C++) i un llenguatge matemàtic algèbric molt potent (GAMS). La interacció entre aquests dos mons permet la flexibilitat i la genericitat del sistema d’optimització desenvolupat A partir d’aquest sistema d’optimització, els diferents capítols de la tesi produeixen resultats operatius rellevants. Això no només demostra que el sistema pot fer front a una gran varietat de problemes, sinó que també contribueix a l’objectiu final d’augmentar de forma segura la capacitat de l’espai aeri i l’eficiència del transit aeri. Es presenten diferents casos d’ ´ us i exemples il·lustratius centrats en enlairaments dins l’àrea de maniobra terminal (TMA). Concretament, quatre etapes formen aquesta part de la tesi. Primer, es presenta una avaluació de l’eficiència dels temps requerits d’arribada (RTA) com a forma d’augmentar la capacitat del transit aeri. Aquest estudi proporciona resultats sobre el cost en termes de combustible i temps d’imposar aquests requisits de temps dins d’una TMA (que pot arribar a xifres sorprenentment baixes). A més, mostra com d’efectiva pot ser aquesta estratègia per a la separació del transit. En segon lloc, es presenta la implementació d’una metodologia de separació d’avions mitjançant el sistema d’optimització. En ella, una aeronau (l’aeronau) genera una predicció de trajectòria d’un avio extern amb qui preveu tenir un conflicte proper (l’intrús). Seguidament, l’aeronau calcula la seva pròpia trajectòria òptima que es desvia d’aquella predita de l’intrús. S’implementa una estratègia de control de la conformitat per assegurar que la separació es mantingui durant tot el vol, reconeixent les desviacions i reaccionant en conseqüència. En tercer lloc, la predicció de la trajectòria intrusa es veu millorada per l’estimació d’una massa equivalent mitjançant estats passats coneguts (el deixant). Com era d’esperar, com més llarg sigui aquest deixant, millor serà l’estimació de la massa. Tanmateix, s’aconsegueix una precisió impressionant molt poc després de l’inici del vol. Finalment, es presenta la implementació d’una estratègia de separació de múltiples aeronaus. En aquesta formulació, s’optimitzen simultàniament les trajectòries de diversos avions dins el mateix problema d’optimització, mantenint la separació entre ells. La complexitat de l’alineació temporal de les coordenades d’avions per a una comparació justa s’aborda des d’una perspectiva innovadora. En conclusió, es comparen les diferents estratègies de separació d’avions i, sorprenentment, els millors resultats de cada estratègia són força similars. De fet, l’augment del cost operatiu que presenten les diferents estratègies (en comparació amb la trajectòria òptima individual) és insignificant i sempre millor que el paradigma actual de separació del control de trànsit aeri.
Wennberg, David. "Multi-Functional Composite Design Concepts for Rail Vehicle Car Bodies." Doctoral thesis, KTH, Järnvägsgruppen, JVG, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-122391.
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Eißner, Tobias [Verfasser]. "The new PWO crystal generation and concepts for the performance optimisation of the PANDA EMC / Tobias Eißner." Gießen : Universitätsbibliothek, 2013. http://d-nb.info/1068874198/34.
Alix, Guillaume Champoussin Jean-Claude. "Comparaison de concepts de moteur diesel en vue de leur hybridation Bilan des émissions de Co2 suuivant l'usage en véhicule /." Ecully : Ecole Centrale de Lyon, 2008. http://bibli.ec-lyon.fr/exl-doc/galix.pdf.
Gosselin, Émilie. "Optimisation des soins de santé par l'application de concepts Lean à Domrémy Mauricie/Centre-Du-Québec centre de réadaptaion en dépendance." Thèse, Université du Québec à Trois-Rivières, 2013. http://depot-e.uqtr.ca/6872/1/030466632.pdf.
Rached, Rabih Pla Fernand. "Mise au point de nouveaux outils et de concepts de modélisation et d'optimisation pour l'élaboration anionique par extrusion réactive de matériaux macromoléculaires multiphasés et nanostructurés à base de polyamides." Vandoeuvre-les-Nancy : INPL, 2005. http://www.scd.inpl-nancy.fr/theses/2005_RACHED_R.pdf.
Abo, Al-Kheer Abd Al-Kareem. "Intégration des concepts d'optimisation et de fiabilité dans la conception des machines agricoles." Phd thesis, INSA de Rouen, 2010. http://tel.archives-ouvertes.fr/tel-00563690.
Poggi, Bastien. "Développement de concepts et outils d’aide à la décision pour l’optimisation via simulation : intégration des métaheuristiques au formalisme DEVS." Thesis, Corte, 2014. http://www.theses.fr/2014CORT0012.
In the world in witch we live the efficient needs are increasing in various fields like industry medecine and environnemtale monitoring. To meet this needs, many optimization methods nammed « metaheuristics » have been created over the last forty years. They are based on probabilistic and random reasoning and allow user to solve problems for witch conventional methods can not be used in acceptable computing times. Victim of their methods succes, the developers of the methods have to answer to several questions : « How can the fitness of solutions be assessed ? », « How to use the same method for several projects without change the code? », « What method will we choose for a specific problem ? », « How to parametrize algorithms ? ». To deal with this problem, we have developed a set of concepts and tools. They have been developed in the context of modeling and simulation of discrete event systems with DEVS formalism. The aims pursued are : allow temporized and spacialized optimization of existing DEVS models, improve the optimization process efficiency (quality of solutions, computing time). Modeling and simulation are used to propose parameters toward the input of problem to optimize. This one generate results used to improve the next proposed solutions. In order to combine optimization and simulation, we propose to represent the optimization method as models which can be easily interconnected and simulated. We focus on consistency of exchanges between optimization models and problem models. Our approach allows early stopping of useless simulations and reduce the computing time as a result. Modeling optimization methods in DEVS formalism also allows to autimatically choose the optimization algorithm and its parameters. Various algorithms and parameters can be used for the same problem during optimization process at different steps. This changes are influenced by collected results of problem simulation. They lead on a self adaptation to the visible or/and hidden features of the studied problem. Our models architecture has been tested on three different problems : parametric optimization of mathematical functions, spacialized optimization of a sensor network deployment, temporized optimization of a medical treatment. Genericity of our concepts and scalability of our models underline the usabily of proposed tool. Concerning performance, simulation breaks and dynamic optimization have obtained higher quality solutions in a short time
Alix, Guillaume. "Comparaison de concepts de moteur diesel en vue de leur hybridation : Bilan des émissions de Co2 suuivant l'usage en véhicule." Ecully, Ecole centrale de Lyon, 2008. http://www.theses.fr/2008ECDL0003.
The reduction of fuel consumption and the increase of electrical power in vehicles have furthered the development of hybrid vehicle. Internal combustion engine (ICE) doesn’t meet same requirement in hybrid powertrain than in conventional powertrain. However, main improvements concerning ICE are aimed at reducing fuel consumption in conventional powertrain equipped vehicles. Question is to know if these improvements represent same advantages in conventional and hybrid architecture in terms of fuel consumption reduction. A Diesel turbocharged engine model has been developed on GT-Power according to test bed measurements. This reference model has been modified to account for different engine evolution (namely downsizing and cylinders deactivation). Computations have been lead modified engine consumption. Resulting Fuel consumption maps have been integrated in complete vehicle models, defined by different powertrain architectures and electrical power levels. Potential optimal fuel consumption have been evaluated for these vehicles with an energy management strategy optimization algorithm, considering a normalisation driving cycle and three "real use" driving cycles. Evaluation process has been issued for three powertrain types, nine electrical power levels and three engine fuel consumption maps. Results give an overview of engine improvement influence on fuel consumption in hybrid powertrain, compared to conventional powertrain
Rached, Rabih. "Mise au point de nouveaux outils et de concepts de modélisation et d'optimisation pour l'élaboration anionique par extrusion réactive de matériaux macromoléculaires multiphasés et nanostructurés à base de polyamides." Vandoeuvre-les-Nancy, INPL, 2005. http://docnum.univ-lorraine.fr/public/INPL/2005_RACHED_R.pdf.
Ces travaux de recherche ont pour but l'élaboration des mélanges de polyamide 12 (PA12) et de polydiméthylsiloxane (PDMS), selon une démarche originale reposant sur la synthèse simultanée, par voie anionique, du polyamide et d'un compatibilisant, durant l'élaboration du mélange par extrusion réactive. Cela conduit à la structuration du matériau sous la forme d'une phase continue (PA12) au sein de laquelle l'élastomère, qui est stabilisé par le compatibilisant, est finement dispersé. Le mécanisme de formation de la morphologie est alors complètement différent de celui mis en œuvre dans les autres procédés. Les deux phases étant alors liées de manière très intime, il en résulte une amélioration remarquable des propriétés mécaniques des matériaux, en particulier leur tenue au choc. A cette fin, un modèle cinétique des deux polymérisations a été élaboré. Par ailleurs, la synthèse complète d'un nouveau macroactivateur a été réalisée pour former in situ le compatibilisant. Avant la mise en oeuvre du procédé d'extrusion réactive, des études préalables ont été nécessaires afin d'étudier l'influence des conditions opératoires et la composition du milieu sur les propriétés finales des matériaux. Pour conduire de façon optimale le procédé, des nouveaux outils et concepts scientifiques ont été élaborés. Ces outils, issus d'une expérimentation importante, sont des modèles prédictifs et des algorithmes d'optimisation multicritère qui se sont avérés très utiles pour la fabrication de ces matériaux et pour la conduite des procédés correspondants
Company, Olivier. "Machines-outils rapides à structure parallèle : Méthodologie de conception, applications et nouveaux concepts." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2000. http://tel.archives-ouvertes.fr/tel-00481184.
Abo, Al-Kheer Abd Al-Kareem. "Intégration des concepts d’optimisation et de fiabilité dans la conception des machines agricoles." Thesis, Rouen, INSA, 2010. http://www.theses.fr/2010ISAM0024/document.
Agricultural machines should be designed to be optimal, reliable and have thecapacity to resist failure by fatigue. Although, the deterministic design approach does not guarantee these requirements, it is traditionally applied in the design of agricultural machines. This is due to the difficulties to model the stochastic nature of the forces acting on agricultural machines, especially the forces acting on tillage machines which work in irregular environment and under varying conditions. Therefore, the main objective of this dissertation is to develop a general framework for the design of agricultural machines by integrating the optimization, the reliability and the fatigue tools. We aim to provide an alternative to the traditional deterministic design one. First, this dissertation proposes methods and models for modeling the variability in tillage forces considering both thevariability in tillage system parameters and the soil failure. Second, based on the available methods in reliability-based design optimization and fatigue analysis approaches, itproposes methodologies for the design of agricultural machines. Throughout the dissertation, the developed approaches are applied to the design of the shack of a chisel plough
Etienne, Alain. "Intégration Produit / Process par les concepts d'activités et de caractéristiques clés - Application à l'optimisation de l'allocation des tolérances géométriques." Phd thesis, Université de Metz, 2007. http://tel.archives-ouvertes.fr/tel-00224938.
Ingremeau, Jean-Jacques. "Méthodologie d’optimisation d’un coeur de réacteur à neutrons rapides, application à l’identification de solutions (combustible, coeur, système) permettant des performances accrues : étude de trois concepts de coeurs refroidis à gaz, à l’aide de l’approche FARM." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112253/document.
In the study of any new nuclear reactor, the design of the core is an important step. However designing and optimising a reactor core is quite complex as it involves neutronics, thermal-hydraulics and fuel thermomechanics and usually design of such a system is achieved through an iterative process, involving several different disciplines. In order to solve quickly such a multi-disciplinary system, while observing the appropriate constraints, a new approach has been developed to optimise both the core performance (in-cycle Pu inventory, fuel burn-up, etc…) and the core safety characteristics (safety estimators) of a Fast Neutron Reactor. This new approach, called FARM (FAst Reactor Methodology) uses analytical models and interpolations (Metamodels) from CEA reference codes for neutronics, thermal-hydraulics and fuel behaviour, which are coupled to automatically design a core based on several optimization variables. This global core model is then linked to a genetic algorithm and used to explore and optimise new core designs with improved performance. Consideration has also been given to which parameters can be best used to define the core performance and how safety can be taken into account.This new approach has been used to optimize the design of three concepts of Gas cooled Fast Reactor (GFR). For the first one, using a SiC/SiCf-cladded carbide-fuelled helium-bonded pin, the results demonstrate that the CEA reference core obtained with the traditional iterative method was an optimal core, but among many other possibilities (that is to say on the Pareto front). The optimization also found several other cores which exhibit some improved features at the expense of other safety or performance estimators. An evolution of this concept using a “buffer”, a new technology being developed at CEA, has hence been introduced in FARM. The FARM optimisation produced several core designs using this technology, and estimated their performance. The results obtained show that this innovative feature leads to much higher performing and/or safer cores. The FARM approach has also been applied to a GFR concept using a vanadium cladding. However the large uncertainties involved do not really enable one to evaluate the performance of this promising concept.In summary, the feasibility of a global multi-disciplinary optimization has been demonstrated. Although the resulting method (FARM) is less accurate than the conventional method, it allows fast optimization and permits a large number of cores to be explored quickly, and is ideally suited for the preliminary designs studies before further refinement of the core design
Ingremeau, Jean-Jacques. "Méthodologie d'optimisation d'un coeur de réacteur à neutrons rapides, application à l'identification de solutions (combustible, coeur, système) permettant des performances accrues : étude de trois concepts de coeurs refroidis à gaz, à l'aide de l'approche FARM." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00660567.
Benama, Youssef. "Formalisation de la démarche de conception d'un système de production mobile : intégration des concepts de mobilité et de reconfigurabilité." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0001/document.
In this thesis we analyse how the concept of mobility can be taken into account in the analysis and design of production systems. Our contribution aims to formalize the analysis and design process, explaining the decisions, the necessary information and decision criteria to be taken into account. For this purpose, two levels of analysis were distinguished: a local level concerning one production site and a global level including a set of sites.The first level considers one production site. At this level we have proposed an approach that takes into account the characteristics of the production site. In our context, the choice of the geographical location of production is imposed by the final client. Therefore, the design of the production system should be adapted to this constraint. From a design perspective, four questions are addressed: (1) To what extent the concept of mobility can be integrated into a mobile production system design approach? (2) What characteristics of the production environment must be taken into account? (3) How to determine what to produce on site or that it would be appropriate to outsource? And (4) taking into account all obtained information what is the best configuration of the mobile production system to consider and according towhich criteria? The answer to these questions led to the proposal of a configuration of SPM suitable for a single production site.The second Level of analysis addresses the problem of global mobility. In order to be profitable, the production system must be used on several production locations. every change of production location led to a need of reconfiguration of the Production System. Reconfigurability Concerns the internal architecture of the system (machine selection, recruitment News local teams, etc.) as well as the organization of the SPM supply chain. Fot this global level, we propose two analytical models: (1) the first model for the analysis of internal reconfigurability. This analysis model is used to adapt the number of production lines and the number of teams according to a production scenario (Geographical locations, necessary capacity per site). The originality of our proposal consists on the assessment of costs to support reconfiguration and the appreciation the convenience level with the context of the production site by using the mobility indicator. (2) Second model to analyse Concerns reconfigurability of the upstream supply chain of PMS. It Consists in June adaptation of the model using the decision "to do ou do" by integrating A side of the importance of the production site and another side Specifics Each of the production site.The proposed approach is illustrated on an industrial case concerning the design of a mobile manufacturing plant used to produce in-site and Install components of solar plant
Auvray, Thomas. "Systèmes catalytiques pour la photosynthèse artificielle : optimisation par l'application des concepts du design moléculaire en chimie de coordination." Thèse, 2019. http://hdl.handle.net/1866/23399.
In the current ecological and environmental context, Mankind needs to find alternative energy sources to replace fossil fuels, as their combustion is a major cause of the current global climate change affecting our daily life a bit more each year. Inspired by Nature and the photosynthetic process, a new area at the interface between chemistry, physics and engineering has emerged in the 70s: artificial photosynthesis. Since then, many catalytic systems have been reported but their integration at commercial scale has not yet been achieved. Several challenges remain to improve their performances, ensure efficient coupling between the different reactions and enhance the long-term stability of these devices. Within this doctoral thesis, we have focused on exploring the coordination chemistry of ruthenium and rhenium complexes, ubiquitous in the literature though their properties can still be vastly tuned by designing new ligands. In a different approach, polyoxometalates, which are inorganic compounds half-way between oxides and molecules with fascinating properties, were recruited to develop covalent dyads, a strategy enabling stabilization of the dye under photocatalytic conditions.
Murray, Phillip Edward. "Designing sustainable distributed generation systems for rural communities : an application of optimisation modelling and decision analysis to include sustainability concepts and uncertainty into design optimality : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Agricultural Engineering (Renewable Energy) at Massey University, Palmerston North, New Zealand." 2005. http://hdl.handle.net/10179/1566.