Дисертації з теми "Approches modales"
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Demri, Stéphane P. "Approches directe et par traduction en logiques modales : nouvelles stratégies et traduction inverse de preuves." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0161.
Повний текст джерелаKari, Nadia. "Design methodology and modal analysis of electricallysmall antennas integrated in lossy dielectric media." Electronic Thesis or Diss., Université Gustave Eiffel, 2023. http://www.theses.fr/2023UEFL2024.
Повний текст джерелаThe demand for miniaturized wireless and autonomous communication system has climbed thanks to the wide need of wireless technologies for the monitoring of infrastructures health of our cities, in marine or in the bio-medical field … However, miniaturized antennas are generally characterized by low efficiencies and poor performances and with the presence of lossy media in the vicinity, enhancing its efficiencies becomes not straightforward task. Methods developed to enhance the performance of electrically small antennas ESAs are generally focused on one of the antenna key parameters since there is a compromise trade-off between the size, bandwidth, impedance matching and radiation efficiency. Most of these methods require trial and error and rely on understanding the physical mechanism of the ESA. Moreover, they are limited to canonical structures. On the other hand, there are methods based on the evaluation of the net energy stored in the near field region. By minimizing this stored energy, the quality factor can be enhanced and the radiation mechanism can be improved. These methods are principally based on the use of modal analysis that decompose the surface current response into modes and to extract the eigenvalues and eigenvectors of each mode. It has also been shown that the use of the artificial materials known as metamaterials can play a key role in energy compensation (magnetic coupled to electrical energy and vice versa). It could enhance efficiency, thus mitigating power effects. To date, these methods have been proposed for ESAs radiating in free space.The aim of this thesis is therefore to propose a general method for designing, analyzing andimproving ESAs radiating into lossy media. This work is based on the evaluation of the netstored energy method and the use of the metamaterials for mitigating the effects of losses.Modal methods are also investigated thanks to their useful and powerful metrics for analyzing the electromagnetic response of the structure in the near and far-field regions. The Expansion Eigen Method EEM is used to evaluate the different metrics such as the eigenmodes, eigencurrents and net stored energy to have a full information about the electromagnetic response of the antenna when it is placed in lossy media. The multi-layer substrate model is used to design the surrounding environment and each layer has the dielectric properties that correspond to the host bodies while keeping the 3D radiating structure. The use of the multi-layer substrate model is to avoid the time consuming issue of classical 3D methods. The proposed generic method show usefulness for designing and analyzing of parasitic metamaterials systems to enhance electrically small antennas in complex and lossy media
Oulad, Haj Thami Rachid. "Approche modale en segmentation d'images." Tours, 1992. http://www.theses.fr/1992TOUR4011.
Повний текст джерелаHétu, Sébastien. "Approche écologique et multi-modale pour étudier l'observation d'actions." Doctoral thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/25407.
Повний текст джерелаDuring action observation, the perception-action system is responsible for the coupling between the visual and motor representations of observed movement. This coupling induces motor priming effects that could be useful for training the motor system of different clinical populations. This thesis main objective was to test if the effect induced by the observation of simple movements could be obtained during the observation of everyday movements. In order to answer this question, the effect of action observation was studied in healthy subjects using approaches in line with the interests of the rehabilitation domain. Furthermore, we aimed at investigating inter-individual differences in the response to action observation and differences pertaining to the method used to measure this response. Results suggest that the perception-action system is recruited to a greater extend by unfamiliar actions. Our data also indicate that observation of everyday movements can produce anatomically congruent facilitation patterns. Importantly, the magnitude and the pattern of response to action observation greatly vary between individuals. Results also indicate that the facilitation effects can vary depending on the method used to study action observation. Indeed, there seem to be no relation between the behavioral and physiological markers of motor facilitation induced by action observation. Similar to what was shown in studies using simple movements, observing everyday movements can induce a pattern of motor facilitation where the visual representation of the observed movement is associated with its representation in the observer’s motor repertoire. The important inter-individual differences in the effects produced by action observation suggest that some individuals could respond more easily to action observation than others. Hence, identifying patients for whom rehabilitation using action observation could be the most beneficial could ensure a more efficient use of this approach. An important future step in the clinical use of action observation will be the identification of markers that could best predict the clinical improvements produced with action observation.
Serra, Roger. "Sur une approche statistique de l'identification modale des structures." Besançon, 1999. http://www.theses.fr/1999BESA2055.
Повний текст джерелаLe, Goïc Gaëtan. "Qualité géométrique & aspect des surfaces : approches locales et globales." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00777746.
Повний текст джерелаLe, Gorrec Yann. "Commande modale robuste et synthèse de gains autoséquencés : approche multimodèle." Toulouse, ENSAE, 1998. http://www.theses.fr/1998ESAEA001.
Повний текст джерелаZhou, Changwei. "Approche couplée propagative et modale pour l'analyse multi-échelle des structures périodiques." Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0040/document.
Повний текст джерелаStructural dynamics can be described in terms of structural modes as well as elastic wave motions. The mode-based methods are widely applied in mechanical engineering and numerous model order reduction (MOR) techniques have been developed. When it comes to the study of periodic structures, wave description is mostly adopted where periodicity is fully exploited based on the Bloch theory. For complex periodic structures, several MOR techniques conducted on wave basis have been proposed in the literature. In this work, a wave and modal coupled approach is developed to study the wave propagation in periodic structures. The approach begins with the modal description of a unit cell (mesoscopic scale) using Component Mode Synthesis (CMS). Subsequently, the wave-based method -Wave Finite Element Method (WFEM) is applied to the structure (macroscopic scale). The method is referred as “CWFEM” for Condensed Wave Finite Element Method. It combines the advantages of CMS and WFEM. CMS enables to analyse the local behaviour of the unit cell using a reduced modal basis. On the other hand, WFEM exploits fully the periodic propriety of the structure and extracts directly the propagation parameters. Thus the analysis of the wave propagation in the macroscopic scale waveguides can be carried out considering the mesoscopic scale behaviour. The effectiveness of CWFEM is illustrated via several one-dimensional (1D) periodic structures and two-dimensional (2D) periodic structures. The criterion of the optimal reduction to ensure the convergence is discussed. Typical wave propagation characteristics in periodic structures are identified, such as pass bands, stop bands, wave beaming effects, dispersion relation, band structure and slowness surfaces...Their proprieties can be applied as vibroacoustics barriers, wave filters. CWFEM is subsequently applied to study wave propagation characteristics in perforated plates and stiffened plate. A homogenization method to find the equivalent model of perforated plate is proposed. The high frequency behaviours such as wave beaming effect are also predicted by CWFEM. Three plate models with different perforations are studied. Experimental validation is conducted on two plates. For the stiffened plate, the influence of internal modes on propagation is discussed. The modal density in the mid- and high- frequency range is estimated for a finite stiffened plate, where good correlation is obtained compared to the mode count from modal analysis
Leturc, Christopher. "Raisonner sur la manipulation dans les systèmes multi-agents : une approche fondée sur les logiques modales." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC236.
Повний текст джерелаIn recent decades, computer development has shifted from designing individual software to designing intelligent, self-contained software called agents and interacting with others to form multi-agent systems. In such systems, malicious agents sometimes implement complex strategies to induce other agents to make decisions in their favor, without the latter noticing them. We are talking about manipulation strategies. These strategies may in some cases cause problems for the agents which are victims. Such strategies are always hidden from agents and therefore hard to detect. How detect them and better fight them? Firstly, it is necessary to define manipulation. Thus, based on work from computer sciences and social sciences, we define manipulation as the deliberate intention of an agent to instrumentalize a victim while making sure to conceal that intent. We propose to answer this question, a logical system named KBE which expresses manipulation. We prove that KBE is correct and complete, and is able to express strategies based on knowledge and beliefs of agents, like lying or bullshiting. This system can also express notions such as coercion and persuasion. Secondly, since trust is a mechanism to regulate the interactions between agents when agents may be malicious or unreliable, we propose another logical system named TB. This system, proved to be correct and complete, expresses a notion of trust in sincerity which represents the choice of an agent to take the risk of believing another agent for its sincerity. Finally, we propose an algorithmic method to reason with such systems. This method is adapted to the TB system and decides on its satisfiability problem by directly using the constraints of the framework to build a model
Goursaud, Benjamin. "Etude mathématique et numérique de guides d'ondes ouverts non uniformes, par approche modale." Phd thesis, Ecole Polytechnique X, 2010. http://pastel.archives-ouvertes.fr/pastel-00546093.
Повний текст джерелаVial, Benjamin. "Étude de résonateurs électromagnétiques ouverts par approche modale. Application au filtrage multispectral dans l'infrarouge." Phd thesis, Ecole centrale de Marseille, 2013. http://tel.archives-ouvertes.fr/tel-00918651.
Повний текст джерелаJezzine, Karim. "Approche modale pour la simulation globale de contrôles non-destructifs par ondes élastiques guidées." Bordeaux 1, 2006. http://www.theses.fr/2006BOR13241.
Повний текст джерелаJezzine, Karim. "Approche modale pour la simulation globale de contrôles non-destructifs par ondes élastiques guidées /." [Gif-sur-Yvette] : [CEA Saclay, Direction des systèmes d'information], 2007. http://catalogue.bnf.fr/ark:/12148/cb41067572s.
Повний текст джерелаPelat, Adrien. "Approche modale de la propagation acoustique dans les guides d'ondes ouverts : application à l'acoustique urbaine." Phd thesis, Le Mans, 2009. http://cyberdoc.univ-lemans.fr/theses/2009/2009LEMA1014.pdf.
Повний текст джерелаIn urban areas, noise has become the main form of ''pollution'' recognized by the population. To address this major issue for society, much research has helped to describe the acoustic propagation in urban areas. However, as consequence of the high geometrical and physical complexity of urban areas, the energetic models implemented in usual predictive software limit the physical description of sound fields. It appears that fundamental work on acoustic propagation in complex environments must be pursued upstream from applications directly related to urban acoustics. In this context of upstream research, the essential idea of this work is to consider the street as an open waveguide. Indeed, the typical elongated shape promotes guided waves along the axis of the street. In contrast, the opening of this guide on an infinite domain - the sky - results in wave radiation leading to energy losses. The study of these competitive effects between guided waves and radiated waves is the key point of this work. To solve the wave equation in such an open three-dimensional guide, the principle of modal decomposition is used. In this approach, the wave field is a combination of a set of modes (called modal basis) whose contributions notably depend on end conditions at the guide extremities. The extension of the modal approach to the case of open waveguides need to introduce the concept of leaky modes. Through a preliminary study about two-dimensional closed guides with variable cross-section, the possibilities of the modal approach are apprehended in simple cases in order to be extended to the more complex case of three-dimensional open guides. Subsequently, a first work about leaky modes is done in the academic case of an open cylindrical guide with rectangular cross-section. In this work, the behavior and properties of leaky modes are studied in details when they are used in a modal approach. It is notably shown that only a small number of modes is necessary to accurately describe the field. Based on the findings of this first research, a coupled Modal-Finite Elements method, more suitable to the ''urban waveguide'' specificities is proposed. This work shows how, using PML (Perfectly Matched Layers), a new problem of propagation in closed guide may be substituted for the original problem of propagation in open guide. In this approach, several characteristics of the geometrical and physical complexity of urban areas can be taken into account. Illustrations based on the numerical implementation of the method reveal physical phenomena related to irregularities and absorption of facades, or the consideration of meteorological effects, and open both academic and applied research prospects
Cornet, Jean-Michel. "Approche modale des transferts aérauliques dans le bâtiment : mécanismes d’instabilité, bifurcations et dynamique non-linéaire." Lyon, INSA, 1995. http://www.theses.fr/1995ISAL0117.
Повний текст джерела[Thermal comfort relies on a set of fundamental parameters such as the velocity and temperature fields, However the remains a lack of knowledge regarding g the transition between the air flow regimes, we intend to establish a methodology suited to the search of bifurcation of convective flows using a linear stability analysis, followed by a non-linear approach allowing us to definite a relation between amplitude an d frequency of the perturbation, Th e combination of the various numerical methods to compute on one band the basic solution and on the other hand the perturbation, is validated using the case study of double convective boundary layer flow. A generalisation of this set of numerical procedures is applied to the search of the bifurcation in e thermally-driven cavity. This method shows a good agreement with available experimental and numerical data. ]
Grau, Loïc. "Approche analytique modale pour la prévision vibratoire de plaques couplées à des sols : Applications ferroviaires." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0113/document.
Повний текст джерелаThis thesis is concerned with the coupling between a fexural vibrating plate and a stratifed ground. A semi-analytical solution is introduced similar to the equivalent acoustical problem. The ground cross modal impedance is defined in a similar way as the equivalent acoustical impedance. From this definition, the ground added mass, stiffness and damping to the plate are presented. Similarities and discrepancies between the acoustical and the ground cross modal impedance are introduced. Influence of the ground stratification on the plate vibration shows new phenomena especially on the imaginary part of the ground cross modal impedance. A comparison between the model developed in this thesis and an experiment made on a tramway slab has been done as well as a comparison with a numerical model, MEFISSTO developed by P. jean at CSTB. One introduces an extension of the modeling developed and is concerned with modeling two flexural plates to the ground. It can be pointed out that problem formulation is still close to the problem formulation of one plate coupled to the ground. Three different fields of application of such modeling is presented. The first field of application is concerned with ground mitigation due to the passing tramway on. The first plate is the excited plate by the tramway and the second plate, called Horizontal Wave Barrier, is acting at the top surface as a ground attenuator. The second field of application is concerned with the modeling of building foundation. It is shown that the vibration received by the foundation of a building can be an input data for modeling an entire building vibration. The third field of application is concerned with different cases of tramway slab for reduction of ground vibration. Finally one presents an introduction of the use of this ground structure modeling in the case of inverse problem. It is shown that it is possible to identify injected force to the plate by the tramway. Furthermore the ground allows a regularization of the problem in the inversion which is not the case in the acoustical case
Meyrand, Louis. "Modes non linéaires : approches réduites par PGD/HBM et applications aux réponses forcées." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0561.
Повний текст джерелаIn the field of structural vibrations, the increasing performance of computers allows to handle more and more complex and realistic systems. This inevitably leads to the consideration of nonlinear phenomena. The industrial context is also characterized by the need to solve ever larger systems. The work presented in this PhD thesis focuses on the development of algorithmic processes to effectively solve large scale problems in nonlinear dynamics. To do this, the choice is made to calculate the Nonlinear Normal Modes (NNMs) of the structures. These objects are not only representative of the vibratory state of the system but also of its nonlinearities.After having proposed a compact and economical method for calculating NNMs, this manuscript then proposes to exploit the data contained in these objects to quickly plot the response of systems subjected to external forces. The implemented methods perform only a few calculations to achieve this
Wyld, Henry. "Problemes de subordination relatifs a l'expression des valeurs aspectuo-temporelles, modales et causales en anglais contemporain : une approche enonciative." Paris 7, 1998. http://www.theses.fr/1998PA070065.
Повний текст джерелаThe aim of this study, undertaken within the conceptual framework of a. Culioli's "theorie des operations enonciatives", is to explore the postulate that the syntactic procedure known as subordination can be viewed as the surface trace of a single type of operation, namely one pertaining to the specification of the location of the matrix structure, or one of its constituents, relative to the enunciative coordinates of the utterance. The first part (chs. 1-3) is mainly taken up with a general presentation of theoretical points and an overview of the field of study. A general introduction to our approach (ch. L first part), is followed by an attempt at a classification of basic hypotactic configurations (ch. L second part). This is followed (ch. 2) by a discussion of related theoretical issues such as the thematic organisation of "complex" utterances and the question of the preconstruction of subordinate clauses. In ch 3. A comparison is undertaken of utterances featuring subordinate clauses introduced by if and when, this providing a field of application for a certain number of theoretical elements previously introduced. The second part (ch. 4-6) is concerned with subordination as a means of modalisation. Ch. 4, drawing on examples featuring nominal clauses, considers the different ways in which the enunciative "endorsement" of an assertion can be modulated. Chs. 5 and 6 are concerned with the modalising properties of adverbial clauses. The latter field being inseparably tied to the presence of a causal interpropositional relation, this leads on to a more generalised consideration of the linguistic expression of causal relations. The third and final part (chs. 7-8) explores certain facets of temporal subordination. Ch. 7 is a contribution to the modelling of the aspectuo-temporal system of english from an enunciative standpoint. Ch. 8 attempts to lay down a basis for the treatment of the interaction between the different sources of aspectualization (grammatical aspect, lexical aspect of verbs, lexical aspect of subordinators) implicated in complex utterances featuring temporal clauses
Storer, Brigitte. "Contribution à l'étude des transitions guide rectangulaire-ligne de transmission planaire par une nouvelle approche modale." Toulouse, ENSAE, 1996. http://www.theses.fr/1996ESAE0026.
Повний текст джерелаTataie, Laila. "Méthodes simplifiées basées sur une approche quasi-statique pour l’évaluation de la vulnérabilité des ouvrages soumis à des excitations sismiques." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0123/document.
Повний текст джерелаIn the context of building’s protection against seismic risk, simplified analysis techniques, based on quasi-static analysis of pushover, have strongly developed over the past two decades. The thesis aims to optimize a simplified method proposed by Chopra and Goel in 2001 and adopted by American standards FEMA 273. This method is a nonlinear decoupled modal analysis, called by the authors UMRHA (Uncoupled Modal for Response History Analysis) which is mainly characterized by: pushover modal analysis according to the dominant modes of vibration of the structure, setting up nonlinear single degree of freedom systems drawn from modal pushover curves, then determining the history response of the structure by combining of the temporal responses associated with each mode of vibration. The decoupling of nonlinear history responses associated with each mode is the strong assumption of the method UMRHA. In this study, the UMRHA method has been improved by investigating the following points. First of all, several nonlinear single degree of freedom systems drawn from modal pushover curves are proposed to enrich the original UMRHA method, in which a simple elastic-plastic model is used, other elastic-plastic models with different envelope curves, Takeda model taking into account an hysteretic behavior characteristic of structures under earthquakes, and finally, a simplified model based on the frequency degradation as a function of a damage index. The latter nonlinear single degree of freedom model privileges the view of the frequency degradation during the structure damage process relative to a realistic description of hysteresis loops. The total response of the structure is obtained by summing the contributions of the non linear dominant modes to those of linear non dominant modes. Finally, the degradation of the modal shapes due to the structure damage during the seismic loading is taken into account in the new simplified method M-UMRHA (Modified UMRHA) proposed in this study. By generalizing the previous model of frequency degradation as a function of a damage index: the modal shape becomes itself also dependent on a damage index, the maximum displacement at the top of the structure; the evolution of the modal shape as a function of this index is directly obtained from the modal pushover analysis. The pertinence of the new method M-UMRHA is investigated for several types of structures, by adopting tested models of structures simulation under earthquakes: reinforced concrete frame modeled by multifibre elements with uniaxial laws under cyclic loading for concrete and steel, infill masonry wall with diagonal bars elements resistant only in compression, existing building (Grenoble City Hall) with multilayer shell elements and nonlinear biaxial laws based on the concept of smeared and fixed cracks. The obtained results by the proposed simplified method are compared to the reference results derived from the nonlinear response history analysis
Adragna, Pierre-Antoine. "Tolérancement des Systèmes Assemblés, une approche par le Tolérancement Inertiel et Modal." Phd thesis, Chambéry, 2007. http://tel.archives-ouvertes.fr/tel-00403876.
Повний текст джерелаChukwuka, Ozuem Anthony. "Performance enhancement of integrated antennas using metamaterials and characteristic mode theory." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I039.
Повний текст джерелаThe demand for miniaturized mobile wireless systems have increased the need to integrate electrically small antennas which are generally characterized by poor performances and low efficiency. Methods such as the use of dielectric, slots, parasitic components, … have been applied over the years to enhance the performance of such antennas. However they are empirical and based on time-consuming optimisations. Other methods like antenna current optimization based on modal analysis are systematic methods which have been proposed. It has also been shown that the use of artificial materials known as metamaterial inclusions as parasitic element help to improve antenna performance at lower cost. The choice of the right inclusion for an antenna design is complicated especially when the antenna is non-canonical and arbitrary.In this thesis, we propose a systematic method for enhancing the performance of antenna using metamaterial inclusion as a parasitic element. The method is used for designing parasitic metamaterial antenna with the potential to analyse both the radiation and scattering properties of the parasitic metamaterial design. It uses the characteristic modal method to evaluate the quantitative stored energy of metamaterial inclusions which provide quantitative information on the near-field behaviour of the inclusion. The modal stored energy method is compared to the effective parameter method for describing inclusions and they both show good qualitative agreement. In the parasitic metamaterial antenna design process, characteristic mode is applied to get an insight into the radiation properties of the structure and an inclusion is chosen to compensate the stored energy of the antenna element based on the quantity of its modal stored energy. The coupling between the antenna and the inclusion is analysed using the inter-modal coupling co-efficient. It represents the scattering between the antenna and the inclusion and defines how the positioning and separation distance between the two elements affect the overall performance of the metamaterial-inspired system. The proposed methodology is validated with a prototype that show a good agreement between the simulated and measured result. The method is further applied in investigating the enhancement of integrated antenna using electromagnetic cloaking. The cloak couples to the passive element in its vicinity and allow the active antenna element to operate with a better radiation efficiency. The proposed method show usefulness for future design of parasitic metamaterial systems with enhanced performance
CHEN, YI-YUAN. "I : approche spectrale des modes rayonnants dans une ligne microfente. ii: traitement electromagnetique du pseudo court-circuit microfente." Rennes, INSA, 1988. http://www.theses.fr/1988ISAR0002.
Повний текст джерелаGhenna, Sofiane. "Approche multimodale pour la conception d’interface à retour tactile à plusieurs doigts." Thesis, Lille 1, 2016. http://www.theses.fr/2016LIL10115/document.
Повний текст джерелаTactile display devices are used for providing tactile feedback to their users. They can reproduce the illusion of textured surface by controlling the friction between a vibrating surface and a sliding finger on it. For most of these devices, the basic principle is to use a single resonant mode whose frequency and wave form are imposed by the nature of the material and the geometry of the device. The mode is selected to achieve a homogeneous stimulation, and thereby tactile sensation is undifferentiated over the entire surface. The single mode tactile devices are limited for applications which require more varied information on surface.This work introduces a novel approach for tactile feedback based on the superposition of several vibration modes. The modes are excited simultaneously to perform a more complex wave form and are capable to generate multitouch tactile feedback. This approach has been validated for the case of a beam where two vibration modes were superimposed to generate a differentiated tactile simulation with two fingers. Thanks to vector control method applied to a piezoacturator. A tracking system was implemented to give a multitouch illusion based on the positions of the two fingers. This multimodal approach was later extended to the case of a thin plate where different spatial distributions of the displacement have been imposed. The approach developed in this work is also capable to generate and control a travelling wave amplitude and direction. For this reason, we evaluated the interest of travelling waves in touch interfaces. Psychophysical assessments of proposed devices clearly show the interest to use several vibration modes in tactile feedback simulation
Barillon, Franck. "Méthodologies de couplage fort des systèmes dynamiques : approches linéaires et non-linéaires." Thesis, Ecully, Ecole centrale de Lyon, 2011. http://www.theses.fr/2011ECDL0012/document.
Повний текст джерелаIn this thesis we studied the vibratory behaviour of a whole vehicle under engine excitation at low frequencies (0 – 50 Hz) and medium frequencies (200 – 800 Hz). The aim of the thesis was to provide numerical methodologies to take into account coupling effects between all the sub-systems constituting a whole car. In low frequencies, we used a global approach where each subsystem was characterized separately before coupling. First the car body was characterised both experimentally and numerically using a modal appropriation method that is commonly used in the aeronautic field. Numerical shapes of the modes were correlated to experimental shapes. In addition, the amplitude and frequency non linear behaviour of the engine mounts was measured on a test bench. A strong non linear behaviour was observed and stiffness – frequency – amplitude layers were constructed based on those data.Secondly, numerical methods were developed in order to calculate the coupled non linear response between the engine, the engine mounts and the car body. We used a harmonic balance method that allows calculating the non linear dynamics of complex mechanical systems. In order to apply this method to large industrial finite element models, a condensation method on non linear degrees of freedom was developed. This technique is well adapted to problems of linear structures linked together with localnon linear joints. This method was validated on the isolated engine linked to a bench by the engine mounts. Strong non linear phenomena on the rigid body modes of the engine were observed experimentally.A numerical model of the engine was developed and the HBM method allowed reproducing these non linear phenomena. Eventually, the non linear model of the whole vehicle was coupled and excited by different efforts. First we calculated the response of the assembly using the appropriation method. Then, the structure was excited by a real four – cylinder engine excitation.In medium frequencies, we presented an important study for the group Renault concerning the stiffness measurement of the engine mounts. A numerical methodology based on the FRF Based Substructuring(FBS) method was developed. This method was applied to uncouple an engine mount initially coupled to a test bench. The numerical feasibility of the method was proved and allowed to get the own vibratory behaviour of the engine mount despite coupling phenomena with the test bench
Debove, Julien. "Approche de la musique modale et transmission orale de la musique hindoustanie au sein de la dynastie des Rajam." Paris, EHESS, 2015. http://www.theses.fr/2015EHES0180.
Повний текст джерелаDuval, Cédric Arnaud Henri. "Commande robuste des machines asynchrones." Ecully, Ecole centrale de Lyon, 2002. http://www.theses.fr/2002ECDL0032.
Повний текст джерелаDeals with the robust control to parametric uncertainties of the induction motors. Our first approach consists in carrying out a vector control by orientation of rotor field using the compensations terms in order to uncouple and to linearise the voltages/currents transfers. The frequency command is calculated by self control, using the speed and the slip frequency, which is deduced from the equations of the induction motor. The robustness of the control loops of currents is ensured by HÆ correctors single-input single-output, using a simple and effective design method. The control was improved by the use of a Kalman observer which is reduced in delayed state, and extended to two parameters of the motor. Our second approach carries out the removing of the compensations terms and the self control. (. . . )
Vallet, Guillaume. "Une approche incarnée du vieillissement normal et pathologique : compréhension du fonctionnement mnésique selon les interactions entre mémoire et perception." Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29087/29087.pdf.
Повний текст джерелаNormal aging as Alzheimer’s disease are characterized by memory disorders, primarily for episodic memory. These two populations also present a sensory and perceptive decline, which are strongly correlated with their cognitive impairment. The links between memory and perception may be easily explained in the embodied cognition theory. Indeed, embodiment states that knowledge dynamically emerges from a single memory system in which knowledge remains grounded in its properties, essentially sensory-motor properties. Consequently, perception and memory are closer than previously thought and the links between perception and memory moving to the foreground. The objective of the present research is to assess the embodied cognition theory applied to normal aging and Alzheimer’s disease. To this aim, the nature of the semantic multisensory interactions was tested. According to the multiple memory systems framework, these interactions are indirect and semantic, whereas the embodied cognition theory states that these interactions are direct and perceptual. Young adults, healthy elderly and patients with Alzheimer’s disease completed two experiments. Each experiment was composed of a complete neuropsychological battery and one cross-modal priming paradigm (audition to vision). The novelty of the paradigm was to present a visual meaningless mask for half of the sound primes. Experiment 1 was composed of two distinct phases, whereas the prime and the target were presented in the same trial in Experiment 2. The adaptation of the paradigm in Experiment 2 allowed manipulating the semantic congruency in order to test the attention hypothesis that might underlie the cross-modal interactions. The results demonstrated a significant cross-modal priming effect in young and healthy elderly adults. The mask has interfered with the priming effect only in the semantic congruent situations. The mask interference and its specificity support the direct and perceptual nature hypothesis of the semantic multisensory interactions. This is suggesting that young and elderly adults have modal knowledge. Reversely, the patients with Alzheimer’s disease did not show any priming effect while the effect is perceptual. This result supports the cerebral disconnection hypothesis in Alzheimer’s disease. The data taken together suggest that memory disorders in normal aging could be related to a degradation of the quality of their perception and thus of knowledge. Memory impairments in Alzheimer’s disease might come from an integration disorder to bind dynamically the different components of a memory. The present research support the embodied cognition theory and demonstrates the interest of this kind of approach to explore memory functioning in neuropsychology, such as in aging. These approaches open new avenues of research by focusing on processes rather than systems and by putting on the foreground the interactions between memory and perception.
Corradi, Grégoire. "Approches numérique et expérimentale pour des structures à interfaces frottantes : Application au crissement de frein." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEC044.
Повний текст джерелаBrake systems are sometimes prone to squeal noise, which is due to friction-induced self-sustained vibrations, characterized by a set of frequencies above 1kHz. Those vibrations and resulting noises are a source of perturbations for car occupants, which can be nowadays considered as a health issue.This thesis deals with a global strategy to better understand this phenomenon from an experimental point of view and to propose the prediction of squeal noise by numerical approaches. Moreover, experimental observations of squeal occurrences are analyzed to lead to assumptions about the modelisation of numerical finite element models for squeal prediction. A Double Modal Synthesis is also applied to reduce the size of the discrete finite element model of brake system and to save computational time and ressources. The proposed numerical approach starts with a stability analysis with the classical CEA method. Then the determination of nonlinear self-excited vibrations are performed for the unstable cases detected via the CEA method. Finally the acoustic field emitted by the brake system is computed to predict squeal noise.Specific tools are applied for each computational step to assess the efficiency of reduced model versus the reference model: criteria based on the mean error on eigenvalues and the Modal Assurance Criterion analysis (MAC) are used for the stability analysis; comparisons of the limit cycles, spectrograms and the modal contributions of unstable modes are undertaken for the transient responses; patterns of the acoustic intensity are computed on several observations surfaces and a decomposition based on the theory of 2D wavelets is introduced and applied to assess the convergence of patterns
Diop, El Hadji Samba. "Modèles AM-FM et Approche par Équations aux Dérivées Partielles de la Décomposition Modale Empirique pour l'Analyse des Signaux et des Images." Phd thesis, Université Rennes 1, 2009. http://tel.archives-ouvertes.fr/tel-00464849.
Повний текст джерелаTataie, Laila. "Méthodes simplifiées basées sur une approche quasi-statique pour l'évaluation de la vulnérabilité des ouvrages soumis à des excitations sismiques." Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00708575.
Повний текст джерелаRobert, Marie. "Modélisation numérique du comportement hydroélastique des navires sur houle non linéaire." Thesis, Ecole centrale de Nantes, 2017. http://www.theses.fr/2017ECDN0047.
Повний текст джерелаThe increase of large ships dimensions shifts their structural natural frequencies towards common wave frequencies, inducing more interactions between the classic seakeeping response and the structural response. Accurate modeling of wavestructure interactions becomes a key issue for architects and classification societies during the design of a ship. In this respect, a new numerical tool for fluidstructure interaction is developed, combining a finite difference RANSE description of the fluid domain with ICARE-SWENSE and an analytic beam model, within a modal approach. Thanks to the use of a simple formulation for the structure part, the tool inherits ICARE-SWENSE tolerance properties with regard to large time steps, while still taking into account hydrodynamic nonlinear effects. Results presented for a flexible barge in diffraction and radiation according to flexible modes validate the first steps of the coupling procedure. Special consideration is given to hydrodynamic non linearities threshold and their impact on the structural response. A first implementation is shown for the resolution of the equation of motion for the elastic degrees of freedom. Parametric studies on ship resistance in both regular and bichromatic waves are included as a stepping stone towards future simulations of ship hydroelasticity in irregular waves
Sabri, Rida. "Installation des conduites pétrolières en mer profonde par contrôle actif." Paris, ENMP, 2004. http://www.theses.fr/2004ENMP1241.
Повний текст джерелаEl, amer Amani. "Les temps du passé de l’indicatif en français : approche en langue et en discours." Thesis, Lyon 2, 2013. http://www.theses.fr/2013LYO20067.
Повний текст джерелаOur work has for object the times of the past in French (in particular the simple past, the imperfect and the present perfect). The approaches at the time are multiple and they use varied concepts which try to explain the functioning of these forms through of many paradigms. So, the grammar contents with stipulating that the times of the past have for role to place the events in the past time. But, if we confront the traditional theories with the more recent linguistic approaches on semantics of the tenses of the verb, we observe that the use of these times implies at the same time a temporal reference, an aim illocutoire and discursive as well as a psychological and pragmatic attitude. We study in this work the uses in speech of the past time from their values in language by trying to show, first of all, how temporal, aspectual and modal contents interfere and complement each other in the verbal expression of past. We highlight the fact that the choice of the past times is motivated by the way of representing itself the events and by the type of information that the speaker wants to introduce to his interlocutor. The employment of the past times also characterizes particular types of speech and participates in the informative coherence of the text. The treatment of aspectuo-temporal, textual and pragmatic approcaches leads us to adopt the model primarily praxematic for a study of the use of the past times in language and speech in a literary text, Thérèse Desqueyroux of François Mauriac
Alexandru, Mihai. "Efficient large electromagnetic simulation based on hybrid TLM and modal approach on grid computing and supercomputer." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2012. http://tel.archives-ouvertes.fr/tel-00797061.
Повний текст джерелаJmal, Rim. "Développement musical et acquisition du système modal arabe chez l’enfant tunisien de 6 à 13 ans au début du XXIème siècle (approche expérimentale)." Thesis, Paris 4, 2013. http://www.theses.fr/2013PA040048/document.
Повний текст джерелаThe present thesis offers a reflection on the development of 6-to-13 year-old Tunisian children’s musical awareness in the musical context of the XXI century. The basic argument here is whether the Tunisian musical culture that resides primarily in Arabic modal aesthetical system promotes the development of some listening habits among Tunisian children. Also postulated is the development of a modal awareness among the of 6-to-13 years old Tunisian children which boosts the acquisition of particular features of the modal system such as the specific intervals in the range Arab modal scale, the modal hierarchy, and standard formulas specific to a given mode. In its theoretical aspect, this study holds a psychological dimension in its review of literature attendant to the disciplines of psychology of music and musical developmental psychology which are concerned with the study of musical perception in general and the perception of tone in particular. In its practical aspect, the study draws on experimental model advanced by Professor Imberty in his account of the acquisition of the tonal structure among the Western children. The experimental procedure here has been adapted to the context of modal music which is based on the idea of three successive testing episodes related to the working memory, melodic attainment, and melodic vocal production.Keywords: Musical development - musical awareness - Arabic modal system - Tunisian children - memory - melodic attainment - vocal production
Bordier, Luc. "Etude du comportement vibro-acoustique des réservoirs à carburants soumis à l'excitation de la pompe du module d'aspiration par une approche expérimentale et numérique." Compiègne, 2008. http://www.theses.fr/2008COMP1733.
Повний текст джерелаThis work presents the studies made within Inergy Automotive Systems and dealing with experimental testing and numerical computations for vibro-acoustic problems of fuel tanks due to the sender unit fuel pump. Because complains from car drivers about noise perturbation from fuel tanks have increased due to the improvement of the acoustic signature in cars, Inergy Automotive Systems has 1 to start a research study on this issue and has thus asked for a CIFRE grant in 2003. In a first part, this work presents the system in matter and the main goals of the study. In a second part, the theoretical formulation is given and then, in the third part, the modal behavior of partially filled fuel tank is studied. In the fourth part, the vibro-acoustic source (fuel-pump) is studied by experimental testing. At last, in a fifth part, both experimental and numerical model are presented for complete fuel tank assembly
Bonci, Tecla. "La reconstruction du mouvement du squelette : l'enjeu de l'artefact des tissus mous." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10056/document.
Повний текст джерелаIn 3D human movement analysis performed using stereophotogrammetry and skin markers, bone pose can be only indirectly estimated. During a task, soft tissue deformations make the markers move with respect to the underlying bone generating soft tissue artefacts (STA), causing devastating effects on pose estimation and its compensation remains an open issue. The thesis’ aim was to contribute to the solution of this crucial issue. Modelling STA using measurable trial-specific variables is a prerequisite for its removal from marker trajectories. Two STA model architectures are proposed. A thigh marker-level model is first presented. STA was modeled as a linear combination of joint angles involved in the task. The model was calibrated with direct STA measures. The considerable number of model parameters led to defining STA approximations. Three definitions were proposed to represent STA as series of modes : individual marker displacements, marker-cluster geometrical transformations (MCGT), and skin envelope shape variations. Modes were selected using two criteria : modal energy and selecting them a priori. The MCGT allows to select either rigid or non-rigid components. It was also demonstrated that only the rigid component affects joint kinematics. A model of thigh and shank rigid component at cluster-level was then defined. An acceptable trade-off between STA compensation and number of parameters was obtained. These results lead to two main potential applications : generate realistic STAs for simulation
Cheaito, Hassan. "Modélisation CEM des équipements aéronautiques : aide à la qualification de l’essai BCI." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEC039/document.
Повний текст джерелаElectronic equipments intended to be integrated in aircrafts are subjected to normative requirements. EMC (Electromagnetic Compatibility) qualification tests became one of the mandatory requirements. This PhD thesis, carried out within the framework of the SIMUCEDO project (SIMulation CEM based on the DO-160 standard), contributes to the modeling of the Bulk Current Injection (BCI) qualification test. Concept, detailed in section 20 in the DO-160 standard, is to generate a noise current via cables using probe injection, then monitor EUT satisfactorily during test. Among the qualification tests, the BCI test is one of the most constraining and time consuming. Thus, its modeling ensures a saving of time, and a better control of the parameters which influence the success of the equipment under test. The modeling of the test was split in two parts : the equipment under test (EUT) on one hand, and the injection probe with the cables on the other hand. This thesis focuses on the EUT modeling. A "gray box" modeling was proposed by associating the "black box" model with the "extensive" model. The gray box is based on the measurement of standard impedances. Its identification is done with a "pi" model. The model, having the advantage of taking into account several configurations of the EUT, has been validated on an analog to digital converter (ADC). Another approach called modal, in function of common mode and differential mode, has been proposed. It takes into account the mode conversion when the EUT is asymmetrical. Specific PCBs were designed to validate the developed equations. An investigation was carried out to rigorously define the modal impedances, in particular the common mode (CM) impedance. We have shown that there is a discrepancy between two definitions of CM impedance in the literature. Furthermore, the mode conversion ratio (or the Longitudinal Conversion Loss : LCL) was quantified using analytical equations based on the modal approach. An N-input model has been extended to include industrial complexity. The EUT model is combined with the clamp and the cables model (made by the G2ELAB laboratory). Experimental measurements have been made to validate the combined model. According to these measurements, the CM current is influenced by the setup of the cables as well as the EUT. It has been shown that the connection of the shield to the ground plane is the most influent parameter on the CM current distribution
Chebbi, Houssem. "Méthode des coordonnées curvilignes pour la modélisation électromagnétique des matériaux complexes : application au contrôle non destructif par courants de Foucault des matériaux composites The fast computation of eddy current distribution and probe response in homogenized composite material based on semi-analytical approach Investigation of layer interface model of multi-layer structure using semi-analytical and FEM analysis for eddy current pulsed thermography." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST004.
Повний текст джерелаThis doctoral thesis work, carried out within the Laboratory of Simulation and Modeling for Electromagnetics (LSME) of CEA List, is part of the “NDTonAir” European project funded under the action “H2020-MSCA-ITN -2016- GRANT 722134”. The main goal of the project is the development of a fast and accurate simulation tool for the non-destructive eddy current testing of homogenized composite materials. As an application case, we are particularly interested in the orientation of the fibers on the one hand, and on the other hand, in defects as delamination which are manifested by a local geometrical deformation of the interfaces. The semi-analytical methods existing in the literature, based on Green's Dyad formalism, have been limited so far to multilayered and planar structures. To introduce local variations in geometry at the interfaces, we propose an innovative approach based on a change of coordinates adapted to the profile of the local perturbation. We propose a powerful numerical model based on the covariant formalism of Maxwell's equations. This unifying formalism takes in the anisotropy of specimen and the local deformations of the interfaces. The curvilinear coordinate method is usually used to solve diffraction problems on rough interfaces in the high frequency domain (diffraction on gratings). This thesis work is inspired by Fourier Modal Methods and proposes new tools which have been adapted to the field of eddy currents. The extension of the curvilinear coordinate method to the field of eddy currents non-destructive testing technique of composites constitutes the innovation of this work. Two numerical models have been developed to calculate the interaction of the field emitted by an eddy current probe with a multilayered composite material. The numerical model developed for the evaluation of planar composite exploits the particular structures of sparse matrices to reduce the computation time without limiting the number of modes used for the modal expansion of the field. In the case of the curvilinear profiles of the interfaces, the model makes it possible to treat parallel interfaces and some particular cases of non-parallel profiles. The general case of non-identical profiles presents some limitations which require the development of complementary numerical tools. Finally, several testing configurations were considered and the numerical results produced by the models were compared to finite element simulated data. Some experiments were carried out in foreign partner laboratories to increase our experience on experimental validation
Amarouche, Youcef. "Selective and co-modal transport : models and algorithms." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2522.
Повний текст джерелаThe notion of "co-modality" was introduced by the European Commission in 2006 as part of its new transport policy. It refers to the "efficient use of different modes on their own and in combination" for the purpose of achieving "an optimal and sustainable utilisation of resources" [55]. Unlike previous European transport policies, co-modality does not seek to oppose road transportation to its alternatives, but rather seeks to take advantage of the domains of relevance of different transportation modes and of their combinations to optimize services. In this thesis, we focus on developing new solution algorithms for variants of vehicle routing problems for city logistics systems arising in the wake of comodality. We were particularly interested in developing effective solution methods for selective variants of the vehicle routing problem and two-echelon variants. First, we address the Team Orienteering Problem with Time Windows (TOPTW), a selective variant of routing problems that takes into account customer availability. We propose an effective algorithm based on a neighborhood search that alternates between two different search spaces, and uses a long term memory mechanism to benefit from information gathered while exploring the search space, to solve the TOPTW. In the se cond part of this work, we deal with the Two-Echelon Vehicle Routing Problem (2E-VRP), a variant of the problem that introduces intermediate facilities, refered to as « satellites ». In a two echelon system, freight is first moved from the depot to the satellites using large trucks, and then delivered from the satellites to the customers using smaller vehicles. To solve the 2E-VRP, we introduce a novel algorithm that combines heuristic methods with mathematical programming techniques. Finally, we consider the Orienteering Problem with Hotel Selection (OPHS), another selective variant that shares similarities with the 2E-VRP, namely, the use of intermediate facilities called hotels. For this problem, we propose a new integer linear programming model, valid inequalities and a Branch-&-Cut solution method. Extensive experimentation on benchmark instances available in the literature demonstrate the competitiveness of our solution methods
Faraut, Gregory. "Commutations sûres de mode pour les systèmes à événements discrets." Phd thesis, INSA de Lyon, 2010. http://tel.archives-ouvertes.fr/tel-00945172.
Повний текст джерелаOuellette, Nadine. "Changements dans la répartition des décès selon l'âge : une approche non paramétrique pour l'étude de la mortalité adulte." Thèse, 2011. http://hdl.handle.net/1866/5055.
Повний текст джерелаOver the course of the last century, we have witnessed major improvements in the level of mortality in regions all across the globe, in particular in developed countries. This remarkable mortality decrease has also been characterized by fundamental changes in the mortality profile by age. Indeed, deaths are no longer occurring mainly at very young ages but rather at advanced ages such as above age 65. Our research focuses on monitoring and understanding historical changes in the age-at-death distribution among the elderly population. We propose a new flexible nonparametric smoothing approach based on P-splines leading to detailed mortality representations, as described by actual data. The results are presented in three scientific papers, which rest upon reliable data taken from the Human Mortality Database, the Canadian Human Mortality Database, and the Registre de la population du Québec ancien. Findings from the first paper suggest that some low mortality countries may have recently reached the end of the old-age compression of mortality era, where deaths among the elderly population tend to concentrate into a progressively shorter age interval over time. Indeed, since the early 1990s in Japan, the modal age at death continues to increase while reductions in the variability of age at death above the mode have stopped. Thus, the distribution of age at death at older ages has been sliding towards higher ages without changing its shape. In France and Canada, women show such developments since the early 2000s, whereas men are still boldly engaged in an old-age mortality compression regime. In the USA, the picture for the latest decade is worrying because for several consecutive years in that timeframe, women and men have both recorded important declines in their modal age at death, which corresponds to the most common age at death among adults. The second paper takes a look within national boundaries and examines regional adult mortality differentials in Canada between 1930 and 2007. Smoothed mortality surfaces reveal that provincial disparities among adults in general and among the elderly population in particular are substantial in this country and deserve to be monitored closely. More specifically, based on modal age at death and standard deviation above the mode time trends, provincial disparities at older ages have barely reduced during the period studied, despite the great mortality improvements recorded in all provinces since the early XXth century. Also, we find that women who have reached the end of the old-age compression of mortality era in Canada are respectively those of Western and Central provinces. The last paper focuses on adult longevity during the XVIIIth century in historical Quebec and provides new insight on the most common adult age at death. Indeed, our analysis reveals that the modal age at death increased among French-Canadian adults between 1740-1754 and 1785-1799. In 1740-1754, it was estimated at 73 years among females and at about 70 years among males. By 1785-1799, modal age at death estimates were almost 3 years higher for females and 4 years higher for males. Specific living conditions of the French-Canadian population at the time could explain these results.