Thèses sur le sujet « Boîtes noires »
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Laugel, Thibault. « Interprétabilité locale post-hoc des modèles de classification "boites noires" ». Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS215.
Texte intégralThis thesis focuses on the field of XAI (eXplainable AI), and more particularly local post-hoc interpretability paradigm, that is to say the generation of explanations for a single prediction of a trained classifier. In particular, we study a fully agnostic context, meaning that the explanation is generated without using any knowledge about the classifier (treated as a black-box) nor the data used to train it. In this thesis, we identify several issues that can arise in this context and that may be harmful for interpretability. We propose to study each of these issues and propose novel criteria and approaches to detect and characterize them. The three issues we focus on are: the risk of generating explanations that are out of distribution; the risk of generating explanations that cannot be associated to any ground-truth instance; and the risk of generating explanations that are not local enough. These risks are studied through two specific categories of interpretability approaches: counterfactual explanations, and local surrogate models
Dahan, Jean-Jacques. « La démarche de découverte expérimentalement médiée par cabri-géométrie en mathématiques : un essai de formalisation à partir de l'analyse de démarches de résolutions de problèmes de boîtes noires ». Université Joseph Fourier (Grenoble), 2005. https://tel.archives-ouvertes.fr/tel-00356107.
Texte intégralOur work is focused on the process of discovery in the context of experimentations with Cabri-Geometry. The analysis of a corpus going beyond mathematics enlightens the way discovery happens, is possibly transmitted as weil as the role of experimentation in this process. This analysis validates our initial hypothesis breaking out the experimental process of discovery into macro-stages before and after conjecture including micro-stages of "exp loration- interpretation". The analysis of the solving process of a particular black box task allows us to refine our a priori model of discovery process by cIarifying the role of the figure (Duval), the levels of geometry (Parzysz's praxeologies : Gland G2) and the extensions we have developed (G 1 and G2 information), the uames ofinquiry (Millar) and the state of the experimental proof (Johsua). The analysis of the experimentations we carried out provides an improved model that allows teachers to have a minimal knowledge about the heuristic stages of their students' work, to develop analytical studies and research activities with precise aims that are linked with the formalised stages of our model and possibly to evaluate this work. At last, current activities have been analysed with our model and show its adequacy. Activities built to improve specific stages of the process of discovery, show the viability of our model as a basis for creating pedagogic scenarios according to the model
Pernet, Clément. « Algèbre linéaire exacte efficace : le calcul du polynôme caractéristique ». Phd thesis, Université Joseph Fourier (Grenoble), 2006. http://tel.archives-ouvertes.fr/tel-00111346.
Texte intégralLe calcul du polynôme caractéristique est l'un des problèmes classiques en algèbre linéaire. Son calcul exact permet par exemple de déterminer la similitude entre deux matrices, par le calcul de la forme normale de Frobenius, ou la cospectralité de deux graphes. Si l'amélioration de sa complexité théorique reste un problème ouvert, tant pour les méthodes denses que boîte noire, nous abordons la question du point de vue de la praticabilité : des algorithmes adaptatifs pour les matrices denses ou boîte noire sont dérivés des meilleurs algorithmes existants pour assurer l'efficacité en pratique. Cela permet de traiter de façon exacte des problèmes de dimensions jusqu'alors inaccessibles.
Ros, Raymond. « Optimisation Continue Boîte Noire : Comparaison et Conception d'Algorithmes ». Phd thesis, Université Paris Sud - Paris XI, 2009. http://tel.archives-ouvertes.fr/tel-00595922.
Texte intégralAkerma, Mahdjouba. « Impact énergétique de l’effacement dans un entrepôt frigorifique : analyse des approches systémiques : boîte noire / boîte blanche ». Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS187.
Texte intégralRefrigerated warehouses and cold rooms, mainly used for food conservation, constitute available storage cells; they can be considered as a network of "thermal batteries" ready to be used and one of the best existing solutions to store and delay electricity consumption. However, the risk related to temperature fluctuations of products due to periods of demand response - DR* and the risk of energy overconsumption limit the use of this strategy by industrials in food refrigeration. The present PhD thesis aims to characterize the electrical DR of warehouses and cold rooms by examining the thermal behavior of those systems, in terms of temperature fluctuation and electrical consumption. An experimental set-up was developed to study several DR scenarios (duration, frequency and operating conditions) and to propose new indicators to characterize the impact of DR periods on the thermal and energy behavior of refrigeration systems. This study has highlighted the importance of the presence of load to limit the temperature rise and thus to reduce the impact on stored products. The potential for DR application in the case of a cold store and a cold room was assessed, based on the development of two modeling approaches: “black box” (Machine Learning by artificial neural networks using Deep Learning models) and “white box” (physics). A possibility of interaction between these two approaches has been proposed, based on the use of black box models for prediction and the use of the white box model to generate input and output data
Bout, Erwan David Mickaël. « Poïétique et procédure : pour une esthétique de la boîte noire ». Paris 1, 2009. http://www.theses.fr/2009PA010631.
Texte intégralKadmiri, Younes. « Analyse vibroacoustique du bruit de graillonnement des boîtes de vitesses automobiles ». Phd thesis, Ecole Centrale de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00670454.
Texte intégralBarbillon, Pierre. « Méthodes d'interpolation à noyaux pour l'approximation de fonctions type boîte noire coûteuses ». Phd thesis, Université Paris Sud - Paris XI, 2010. http://tel.archives-ouvertes.fr/tel-00559502.
Texte intégralSaives, Jérémie. « Identification Comportementale "Boîte-noire" des Systèmes à Evénements Discrets par Réseaux de Petri Interprétés ». Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLN018/document.
Texte intégralThis thesis proposes a method to identify compact and expressive models of closed-loop reactive Discrete Event Systems (DES), for reverse-engineering or certification. The identification is passive, and blackbox, accessible knowledge being limited to input/output signals. Interpreted Petri Nets (IPN) represent both the observable behaviour (direct input/output causalities) and the unobservable behaviour (internal state evolutions) of the system. This thesis aims at identifying IPN models from an observed sequence of I/O vectors. The proposed contributions extend previous results towards scalability, to deal with realistic systems who exhibit concurrency.Firstly, the construction of the observable part of the IPN is improved by the addition of a filter limiting the effect of concurrency. It detects and removes spurious synchronizations caused by the controller. Then, a new approach is proposed to improve the discovery of the unobservable part. It is based on the use of projections and guarantees the reproduction of the observed behaviour, despite concurrency. An efficient heuristic is proposed to compute a model adapted to reverse-engineering, limiting the computational cost. Finally, a distributed approach is proposed to further reduce the computational cost, by automatically partitioning the system into subsystems. The efficiency of the cumulative effect of these contributions is validated on a system of realistic size
Baudin, Sophie. « Détection et extraction des bruits de type grenaille des boîtes de vitesses par approche cyclostationnaire angle/temps ». Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0118.
Texte intégralThe improvement of the engine noise emissions causes the emergence of new sources which were previously masked, like gearbox noises. Because of the engine acyclism some impacts can appear between the teeth of unloaded gears. Those impacts generate the so called rattle noise which is a current problem for car manufacturers. This work is focused on periodic cases of rattle noise. Their appearance and their level depend on operating conditions. In order to propose a specific detection indicator it is particularly useful to exploit the angle/time duality from measures in non-stationary conditions: the angle domain is linked to the periodicity of the impacts while the time domain is linked to their nature. An extension of the cyclostationary approach is thus exploited and the order/frequency spectral coherence is used to define a severity indicator of rattle noise. The validation of this indicator is obtained from measurements. For a first level of validation, a loose gear has been instrumented with an optical encoder in order to measure the relative velocity between this loose gear and the driving gear. The comparison with the proposed indicator shows its ability to effectively detect the impacts. For a second level of validation some listening sessions have been organized. The evolution of values of our indicator appears in accordance with the feeling of the listeners. After the detection of rattle noise it is interesting to extract its contribution from the measured signal. An extension of the cyclic Wiener filter is thus proposed for angle/time cyclostationary sources. The extracted signal being supposed only produced by impacts, the extracted impulses are then exploited in order to estimate a transfer function. This transfer function is compared with the other one obtained by a second method, also developed in this work. This method exploits the non-stationary regime and proposes a blind identification with cepstrum
Muzammil, Shahbaz Muhammad. « Rétro-conception de modèles d'automates étendus de composant logiciels boîte-noire pour le test d'intégration ». Grenoble INPG, 2008. http://www.theses.fr/2008INPG0166.
Texte intégralA challenging issue in component based software engineering is to deliver quality of service. When components come from third-party sources (aka black boxes), the specifications are often absent/insufficient for their formal analysis. The thesis addresses the problem of uncovering the behaviors of black box software components to support testing and analysis of the integrated system that is composed of such components. We propose to learn finite state machine models (where transitions are labelled with parameterized inputs/outputs) and provide a framework for testing and analyzing the integrated system using the inferred models. The approach has been validated on various case studies provides by France Telecom that has produced encouraging results
Talbo, Vincent. « Étude théorique du transport électronique dans les nanodispositifs à boîtes quantiques semiconductrices ». Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00783430.
Texte intégralChauvineau, Guillaume. « Modélisation de la dynamique des boîtes de vitesses automobiles soumises à des sollicitations acycliques : applications à la prédiction du bruit de grenaille et validation expérimentale ». Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0022.
Texte intégralThe gearbox is an important component of an automobile and its development is complex. Numerous constraints must be taken into account, particularly its noise and vibration behavior. This aspect of the conception is nowadays poorly mastered and the noise pollution of gearboxes, such as the rattle noise, are often discovered late. The aim of this work was the development of a numerical model of gear dynamics adapted to gearboxes’ modelling and allowing to predict the conditions of gear rattle noise appearance. The model proposed in this thesis is based on an original combination of different models and is applicable to the vast majority of gearboxes. Flexible components, such as shafts and housings are modeled by the finite element method. A gear model based on Kelvin-Voigt contact model is developed. It allows to take into account the contact losses and the back side contacts. To complete this model, mechanical loss models are implemented in order to take into account the influence of the bearings, plain bearings, synchronizers and gears’ immersion in oil. This model coupled with a noise indicator allows for sensitivity analyzes to identify influential parameters on the rattle noise but also to compare the dynamic behavior of different configurations. Finally, a test campaign on an industrial gerbox is conducted and simulation results are confronted to measurements
Graux, François. « Méthodologie de modélisation boîte noire de circuits hyperfréquences non linéaires par réseaux de neurones : applications au radar ». Lille 1, 2001. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2001/50376-2001-47.pdf.
Texte intégralBegin, Thomas. « Modélisation et calibrage automatiques de systèmes ». Paris 6, 2008. http://www.theses.fr/2008PA066540.
Texte intégralIrfan, Muhammad Naeem. « Analyse et optimisation d'algorithmes pour l'inférence de modèles de composants logiciels ». Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00767894.
Texte intégralCabana, Antoine. « Contribution à l'évaluation opérationnelle des systèmes biométriques multimodaux ». Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC249/document.
Texte intégralDevelopment and spread of connected devices, in particular smartphones, requires the implementation of authentication methods. In an ergonomic concern, manufacturers integrates biometric systems in order to deal with logical control access issues. These biometric systems grant access to critical data and application (payment, e-banking, privcy concerns : emails...). Thus, evaluation processes allows to estimate the systems' suitabilty with these uses. In order to improve recognition performances, manufacturer are susceptible to perform multimodal fusion.In this thesis, the evaluation of operationnal biometric systems has been studied, and an implementation is presented. A second contribution studies the quality estimation of speech samples, in order to predict recognition performances
Varelas, Konstantinos. « Randomized Derivative Free Optimization via CMA-ES and Sparse Techniques : Applications to Radars ». Thesis, Institut polytechnique de Paris, 2021. http://www.theses.fr/2021IPPAX012.
Texte intégralIn this thesis, we investigate aspects of adaptive randomized methods for black-box continuous optimization. The algorithms that we study are based on the Covariance Matrix Adaptation Evolution Strategy (CMA-ES) algorithm and focus on large scale optimization problems.We start with a description of CMA-ES and its relation to the Information Geometric Optimization (IGO) framework, succeeded by a comparative study of large scale variants of CMA-ES. We furthermore propose novel methods which integrate tools of high dimensional analysis within CMA-ES, to obtain more efficient algorithms for large scale partially separable problems.Additionally, we describe the methodology for algorithm performance evaluation adopted by the Comparing Continuous Optimizers (COCO) platform, and finalize the bbob-largescale test suite, a novel benchmarking suite with problems of increased dimensions and with a low computational cost.Finally, we present the formulation, methodology and obtained results for two applications related to Radar problems, the Phase Code optimization problem and the Phased-Array Pattern design problem
Basset, Julien. « High frequency quantum noise of mesoscopic systems and current-phase relation of hybrid junctions ». Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00635825.
Texte intégralDelagrange, Raphaëlle. « Josephson effect and high frequency emission in a carbon nanotube in the Kondo regime ». Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS319/document.
Texte intégralThis thesis is dedicated to quantum transport through a Kondo impurity, formed in a carbon nanotube quantum dot. We probe the Kondo effect in two situations: in competition with the Josephson effect induced in the nanotube by superconducting contacts and through its high frequency emission. In a first experiment, we have introduced a nanotube in a SQUID in order to measure its supercurrent as a function of the superconducting phase across it. We have measured this quantity in the regime where the Kondo and superconducting correlations are of the same order of magnitude and shown that the ground state of the system, singlet or doublet (corresponding respectively to 0 and π junctions), is then controlled by the superconducting phase. We have also demonstrated that, if a second energy level participates in the transport of Cooper pairs, the 0-π transition is not anymore a first order one as it is the case when only one level is involved. In the second part of the thesis, the carbon nanotube is coupled, at some frequencies determined by a resonator, to a tunnel superconducting junction which is used as an on-chip high-frequency noise detector. This enables the measurement of the emission noise of the quantum dot in the Kondo regime, with reservoirs coupled either symmetrically or not to the dot. Our measurements raise the problem of the spatial asymmetry of the measured noise and seem to show that, the more symmetric is the coupling of the reservoirs to the dot, the more the Kondo resonance is weaken in an out-of-equilibrium situation. Finally, this setup has been used in order to measure the AC Josephson emission of a nanotube contacted with superconducting electrodes, in order to extend our investigation of the competition between the Kondo effect and superconductivity at high frequency. These measurements reveal a decrease of the Josephson emission observed together with a maximum of supercurrent
Romero, Ugalde Héctor Manuel. « Identification de systèmes utilisant les réseaux de neurones : un compromis entre précision, complexité et charge de calculs ». Thesis, Paris, ENSAM, 2013. http://www.theses.fr/2013ENAM0001/document.
Texte intégralThis report concerns the research topic of black box nonlinear system identification. In effect, among all the various and numerous techniques developed in this field of research these last decades, it seems still interesting to investigate the neural network approach in complex system model estimation. Even if accurate models have been derived, the main drawbacks of these techniques remain the large number of parameters required and, as a consequence, the important computational cost necessary to obtain the convenient level of the model accuracy desired. Hence, motivated to address these drawbacks, we achieved a complete and efficient system identification methodology providing balanced accuracy, complexity and cost models by proposing, firstly, new neural network structures particularly adapted to a very wide use in practical nonlinear system modeling, secondly, a simple and efficient model reduction technique, and, thirdly, a computational cost reduction procedure. It is important to notice that these last two reduction techniques can be applied to a very large range of neural network architectures under two simple specific assumptions which are not at all restricting. Finally, the last important contribution of this work is to have shown that this estimation phase can be achieved in a robust framework if the quality of identification data compels it. In order to validate the proposed system identification procedure, application examples driven in simulation and on a real process, satisfactorily validated all the contributions of this thesis, confirming all the interest of this work
Romero, ugalde Héctor manuel. « Identification de systèmes utilisant les réseaux de neurones : un compromis entre précision, complexité et charge de calculs ». Phd thesis, Ecole nationale supérieure d'arts et métiers - ENSAM, 2013. http://pastel.archives-ouvertes.fr/pastel-00869428.
Texte intégralOuenzar, Mohammed. « Validation de spécifications de systèmes d'information avec Alloy ». Mémoire, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6594.
Texte intégralAmara, Meriem. « Maîtrise des émissions conduites des électroniques de puissance ». Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEC047.
Texte intégralThis thesis is focused on the black box EMC modeling of a three-phase inverter for aerospace applications. The work performed in this thesis is carried out in the framework of DGAC project (Directorate General of Civil Aviation) titled MECEP (Control of conducted emissions of power electronics).To protect the network board from the conducted electromagnetic interferences and to meet the EMC standards and especially the aviation standard “DO160F”, an EMC filter is absolutely necessary for each power converter. This disturbance levels generated by this type of system require careful design to ensure the filtering of parasitic currents that propagate in common mode (CM) and differential mode (DM). Therefore, the work of this thesis is devoted to the study of a generic EMC modeling, rapid and able to represent correctly the electromagnetic behavior of the converter from the side of the DC network and from the side of the AC load. This modeling is based on a “black box” representation. The identified EMC model contains disturbance sources and equivalent CM and DM impedances. This type of model is validated for two standard drive chains of 4 kW. It is able to predict the impact of different parameters such as the operating point, the network impedance and the load impedance in the frequency domain. A good agreement is obtained in all cases up to a frequency of 50 MHz Finally, the proposed EMC modeling, which represents the electromagnetic behavior of the DC input side of the converter, is extended to represent the AC output side behavior. The main advantages of the proposed “black box” EMC modeling are the rapidity, the simplicity and the construction without the knowledge of the internal structure of the converter. That can be protected by the industrial secret
Dominique, Cyril. « Modélisation dynamique des modules actifs à balayage électronique par séries de Volterra et intégration de ces modèles pour une simulation de type système ». Paris 6, 2002. http://www.theses.fr/2002PA066106.
Texte intégralLonguet, Delphine. « Test à partir de spécifications axiomatiques ». Phd thesis, Université d'Evry-Val d'Essonne, 2007. http://tel.archives-ouvertes.fr/tel-00258792.
Texte intégralLa sélection des données à soumettre au logiciel peut être effectuée selon différentes approches. Lorsque la phase de sélection d'un jeu de tests est opérée à partir d'un objet de référence décrivant plus ou moins formellement le comportement du logiciel, sans connaissance de l'implantation elle-même, on parle de test « boîte noire ». Une des approches de test boîte noire pour laquelle un cadre formel a été proposé est celle qui utilise comme objet de référence une spécification logique du système sous test.
Le cadre général de test à partir de spécifications logiques (ou axiomatiques) pose les conditions et les hypothèses sous lesquelles il est possible de tester un système. La première hypothèse consiste à considérer le système sous test comme un modèle formel implantant les opérations dont le comportement est décrit par la spécification. La seconde hypothèse a trait à l'observabilité du système sous test. Il faut fixer la forme des formules qui peuvent être interprétées par le système, c'est-à-dire qui peuvent être des tests. On se restreint généralement au moins aux formules qui ne contiennent pas de variables. Une fois ces hypothèses de test posées, on dispose d'un jeu de tests initial, celui de toutes les formules observables qui sont des conséquences logiques de la spécification.
Le premier résultat à établir est l'exhaustivité de cet ensemble, c'est-à-dire sa capacité à prouver la correction du système s'il pouvait être soumis dans son intégralité. Le jeu de tests exhaustif étant le plus souvent infini, une phase de sélection intervient afin de choisir un jeu de tests de taille finie et raisonnable à soumettre au système. Plusieurs approches sont possibles. L'approche suivie dans ma thèse, dite par partition, consiste a diviser le jeu de tests exhaustif initial en sous-jeux de tests, selon un certain critère de sélection relatif à une fonctionnalité ou à une caractéristique du système que l'on veut tester. Une fois cette partition suffisamment fine, il suffit de choisir un cas de test dans chaque sous-jeu de test obtenu en appliquant l'hypothèse d'uniformité (tous les cas de test d'un jeu de test sont équivalents pour faire échouer le système). Le deuxième résultat à établir est que la division du jeu de tests initial n'ajoute pas (correction de la procédure) et ne fait pas perdre (complétude) de cas de test.
Dans le cadre des spécifications algébriques, une des méthodes de partition du jeu de tests exhaustif qui a été très étudiée, appelée dépliage des axiomes, consiste à procéder à une analyse par cas de la spécification. Jusqu'à présent, cette méthode s'appuyait sur des spécifications équationnelles dont les axiomes avaient la caractéristique d'être conditionnels positifs (une conjonction d'équations implique une équation).
Le travail de ma thèse a eu pour but d'étendre et d'adapter ce cadre de sélection de tests à des systèmes dynamiques spécifiés dans un formalisme axiomatique, la logique modale du premier ordre. La première étape a consisté à généraliser la méthode de sélection définie pour des spécifications équationnelles conditionnelles positives aux spécifications du premier ordre. Ce cadre de test a ensuite été d'adapté à des spécifications modales du premier ordre. Le premier formalisme de spécification considéré est une extension modale de la logique conditionnelle positive pour laquelle le cadre de test a été initialement défini. Une fois le cadre de test adapté aux spécifications modales conditionnelles positives, la généralisation aux spécifications modales du premier ordre a pu être effectuée.
Dans chacun de ces formalismes nous avons effectué deux tâches. Nous avons d'une part étudié les conditions nécessaires à imposer à la spécification et au système sous test pour obtenir l'exhaustivité du jeu de tests initial. Nous avons d'autre part adapté et étendu la procédure de sélection par dépliage des axiomes à ces formalismes et montré sa correction et sa complétude. Dans les deux cadres généraux des spécifications du premier ordre et des spécifications modales du premier ordre, nous avons montré que les conditions nécessaires à l'exhausitivité du jeu de test visé étaient mineures car faciles à assurer dans la pratique, ce qui assure une généralisation satisfaisante de la sélection dans ce cadre.
Duan, Jianan. « Dynamic and nonlinear properties of quantum dot lasers for photonic integrated circuits on silicon ». Electronic Thesis or Diss., Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLT050.
Texte intégralSilicon photonics have been introduced to overcome low efficiency and high energy consumption of telecom links using twisted pairs or coaxial cables. This technology provides novel functionality and high performance for applications in high speed communication systems, short reach optical interconnects, and the deployment of optical links from chipto-chip, board-to-board or rack-to-rack (datacom). Silicon is known as a very efficient semiconductor material for waveguiding light in particular owing to the strong index contrast with silica. However, the indirect bandgap of silicon makes light emission from silicon inefficient, and other techniques such as wafer- or flipchip bonding must be investigated if light emission is to be realized. The drawbacks of such heterogeneous integration concentrate on the high cost and the limited scalability. Lasers heterogeneously integrated on silicon are also more sensitive to optical reflections originating from the transition between passive/active interfaces. The best way to overcome these drawbacks is to move on to direct epitaxial growth of IIIV materials on silicon for photonics integration. In this context, quantum dot lasers using semiconductor atoms as a gain medium are ideal because they enable smaller devices, amplification with large thermal stability and high tolerance to epitaxial defects. Ultra-low noise optical transmitters are required not only for the coherent systems but also for future chipscale atomic clocks and radar related applications because of the sensitivity to the frequency noise and intensity noise can strongly affect the bit error rates. To this end, the first part of the thesis reports an intrinsic spectral linewidth as low as 80 kHz and a relative intensity noise less than - 150 dB/Hz in InAs/InP quantum dot lasers. In particular, it is shown that a small vertical coupling is more suitable for low intensity noise operation due to the suppression of the carrier noise in the excited state. The second part of the thesis investigates the dynamic and nonlinear properties of epitaxial quantum dot lasers on silicon. As mentioned above, lasers heterogeneously integrated on silicon are more sensitive to parasitic reflections. When combined with external optical feedback, the laser stability can be dramatically affected. As no on-chip optical isolators integrated with lasers and having sufficient isolation ratio exist, the development of feedback insensitive transmitters remains a major objective. This thesis presents an error-free transmission of an epitaxial quantum dot laser on silicon externally modulated at 10 Gb/s and subjected to 100% optical feedback. Such remarkable feedback insensitivity directly results from the near-zero linewidth enhancement factor, the large damping factor, the strong contrast between the ground state and excited states and a shorter carrier lifetime. These results pave the way for future high-performance photonics integrated circuits on silicon operating without optical isolators
Faye, Papa Abdoulaye. « Planification et analyse de données spatio-temporelles ». Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF22638/document.
Texte intégralSpatio-temporal modeling allows to make the prediction of a regionalized variable at unobserved points of a given field, based on the observations of this variable at some points of field at different times. In this thesis, we proposed a approach which combine numerical and statistical models. Indeed by using the Bayesian methods we combined the different sources of information : spatial information provided by the observations, temporal information provided by the black-box and the prior information on the phenomenon of interest. This approach allowed us to have a good prediction of the variable of interest and a good quantification of incertitude on this prediction. We also proposed a new method to construct experimental design by establishing a optimality criterion based on the uncertainty and the expected value of the phenomenon
Nesme, Vincent. « Complexité en requêtes et symétries ». Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2007. http://tel.archives-ouvertes.fr/tel-00156762.
Texte intégralproblèmes symétriques, dans les cadres du calcul probabiliste classique
et du calcul quantique.
Il est montré, dans le cas quantique, une application de la méthode de
bornes inférieures dite "polynomiale" au calcul de la complexité en
requêtes des problèmes de sous-groupes cachés abéliens, via la technique de "symétrisation".
Dans le cas du calcul probabiliste, sous une hypothèse de "symétrie
transitive" des problèmes, il est donné une formule combinatoire
permettant de calculer la complexité en requêtes exacte du meilleur
algorithme non-adaptatif. De plus, il est mis en évidence que sous
certaines hypothèses de symétrie, ce meilleur algorithme non-adaptatif
est optimal même parmi les algorithmes probabilistes plus généraux, ce qui donne pour la classe de problèmes correspondante une expression exacte de la complexité en requêtes.
Jankovic, Anja. « Towards Online Landscape-Aware Algorithm Selection in Numerical Black-Box Optimization ». Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS302.
Texte intégralBlack-box optimization algorithms (BBOAs) are conceived for settings in which exact problem formulations are non-existent, inaccessible, or too complex for an analytical solution. BBOAs are essentially the only means of finding a good solution to such problems. Due to their general applicability, BBOAs can exhibit different behaviors when optimizing different types of problems. This yields a meta-optimization problem of choosing the best suited algorithm for a particular problem, called the algorithm selection (AS) problem. By reason of inherent human bias and limited expert knowledge, the vision of automating the selection process has quickly gained traction in the community. One prominent way of doing so is via so-called landscape-aware AS, where the choice of the algorithm is based on predicting its performance by means of numerical problem instance representations called features. A key challenge that landscape-aware AS faces is the computational overhead of extracting the features, a step typically designed to precede the actual optimization. In this thesis, we propose a novel trajectory-based landscape-aware AS approach which incorporates the feature extraction step within the optimization process. We show that the features computed using the search trajectory samples lead to robust and reliable predictions of algorithm performance, and to powerful algorithm selection models built atop. We also present several preparatory analyses, including a novel perspective of combining two complementary regression strategies that outperforms any of the classical, single regression models, to amplify the quality of the final selector
Vazquez, Emmanuel. « Modélisation comportementale de systèmes non-linéaires multivariables par méthodes à noyaux et applications ». Phd thesis, Université Paris Sud - Paris XI, 2005. http://tel.archives-ouvertes.fr/tel-00010199.
Texte intégralAli, Marwan. « Nouvelles architectures intégrées de filtre CEM hybride ». Phd thesis, École normale supérieure de Cachan - ENS Cachan, 2012. http://tel.archives-ouvertes.fr/tel-00847144.
Texte intégralBittar, Thomas. « Stochastic optimization of maintenance scheduling : blackbox methods, decomposition approaches - Theoretical and numerical aspects ». Thesis, Marne-la-vallée, ENPC, 2021. http://www.theses.fr/2021ENPC2004.
Texte intégralThe aim of the thesis is to develop algorithms for optimal maintenance scheduling. We focus on the specific case of large systems that consist of several components linked by a common stock of spare parts. The numerical experiments are carried out on systems of components from a single hydroelectric power plant.The first part is devoted to blackbox methods which are commonly used in maintenance scheduling. We focus on a kriging-based algorithm, Efficient Global Optimization (EGO), and on a direct search method, Mesh Adaptive Direct Search (MADS). We present a theoretical and practical review of the algorithms as well as some improvements for the implementation of EGO. MADS and EGO are compared on an academic benchmark and on small industrial maintenance problems, showing the superiority of MADS but also the limitation of the blackbox approach when tackling large-scale problems.In a second part, we want to take into account the fact that the system is composed of several components linked by a common stock in order to address large-scale maintenance optimization problems. For that purpose, we develop a model of the dynamics of the studied system and formulate an explicit stochastic optimal control problem. We set up a scheme of decomposition by prediction, based on the Auxiliary Problem Principle (APP), that turns the resolution of the large-scale problem into the iterative resolution of a sequence of subproblems of smaller size. The decomposition is first applied on synthetic test cases where it proves to be very efficient. For the industrial case, a "relaxation" of the system is needed and developed to apply the decomposition methodology. In the numerical experiments, we solve a Sample Average Approximation (SAA) of the problem and show that the decomposition leads to substantial gains over the reference algorithm.As we use a SAA method, we have considered the APP in a deterministic setting. In the third part, we study the APP in the stochastic approximation framework in a Banach space. We prove the measurability of the iterates of the algorithm, extend convergence results from Hilbert spaces to Banach spaces and give efficiency estimates
Dumas, Jean-Guillaume. « Algorithmes parallèles efficaces pour le calcul formel : algèbre linéaire creuse et extensions algébriques ». Phd thesis, Grenoble INPG, 2000. http://tel.archives-ouvertes.fr/tel-00002742.
Texte intégralTorossian, Léonard. « Méthodes d'apprentissage statistique pour la régression et l'optimisation globale de mesures de risque ». Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30192.
Texte intégralThis thesis presents methods for estimation and optimization of stochastic black box functions. Motivated by the necessity to take risk-averse decisions in medecine, agriculture or finance, in this study we focus our interest on indicators able to quantify some characteristics of the output distribution such as the variance or the size of the tails. These indicators also known as measure of risk have received a lot of attention during the last decades. Based on the existing literature on risk measures, we chose to focus this work on quantiles, CVaR and expectiles. First, we will compare the following approaches to perform quantile regression on stochastic black box functions: the K-nearest neighbors, the random forests, the RKHS regression, the neural network regression and the Gaussian process regression. Then a new regression model is proposed in this study that is based on chained Gaussian processes inferred by variational techniques. Though our approach has been initially designed to do quantile regression, we showed that it can be easily applied to expectile regression. Then, this study will focus on optimisation of risk measures. We propose a generic approach inspired from the X-armed bandit which enables the creation of an optimiser and an upper bound on the simple regret that can be adapted to any risk measure. The importance and relevance of this approach is illustrated by the optimization of quantiles and CVaR. Finally, some optimisation algorithms for the conditional quantile and expectile are developed based on Gaussian processes combined with UCB and Thompson sampling strategies
Cheaito, Hassan. « Modélisation CEM des équipements aéronautiques : aide à la qualification de l’essai BCI ». Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEC039/document.
Texte intégralElectronic 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
Pamart, Pierre-Yves. « Contrôle des décollements en boucle fermée ». Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://tel.archives-ouvertes.fr/tel-00659979.
Texte intégralLoshchilov, Ilya. « Surrogate-Assisted Evolutionary Algorithms ». Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00823882.
Texte intégralDubois, Amaury. « Optimisation et apprentissage de modèles biologiques : application à lirrigation [sic l'irrigation] de pomme de terre ». Thesis, Littoral, 2020. http://www.theses.fr/2020DUNK0560.
Texte intégralThe subject of this PhD concerns one of the LISIC themes : modelling and simulation of complex systems, as well as optimization and automatic learning for agronomy. The objectives of the thesis are to answer the questions of irrigation management of the potato crop and the development of decision support tools for farmers. The choice of this crop is motivated by its important share in the Haut-de-France region. The manuscript is divided into 3 parts. The first part deals with continuous multimodal optimization in a black box context. This is followed by a presentation of a methodology for the automatic calibration of biological model parameters through reformulation into a black box multimodal optimization problem. The relevance of the use of inverse analysis as a methodology for automatic parameterisation of large models in then demonstrated. The second part presents 2 new algorithms, UCB Random with Decreasing Step-size and UCT Random with Decreasing Step-size. Thes algorithms are designed for continuous multimodal black-box optimization whose choice of the position of the initial local search is assisted by a reinforcement learning algorithms. The results show that these algorithms have better performance than (Quasi) Random with Decreasing Step-size algorithms. Finally, the last part focuses on machine learning principles and methods. A reformulation of the problem of predicting soil water content at one-week intervals into a supervised learning problem has enabled the development of a new decision support tool to respond to the problem of crop management
Walker, Étienne. « Quand la ville ne dort pas : s'approprier l'espace-temps hypercentral nocturne par et autour de l'usage récréatif. Les exemples de Caen et Rennes. (Pour une approche aussi sonore des rapports sociaux de proximité) ». Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC032/document.
Texte intégralThrough the examples of Caen and Rennes (France) and the night-time recreational prism, this PHD aims at analysing contemporary city, in a morphogenetic, polemological and dimensional way. Through both spatialised and temporalised qualitative (interviews, speech analysis, press review, archives ans institutional documents) and quantitative (especially statistical approach of censuses and questionnaires) methods, we focus on the mobilisations of night owls, bar owners, residents and institutions who try to appropriate city-center at night. In a first section, the importance of recreational use in the city centers of Caen and Rennes is depicted. As a central attribute of young persons, recreational (more than festive in fact) customs are polarised by a central and abundant commercial offer. Around and sometimes very closely, residents, who are mostly young night owls once they have come back home, but also populations who are much more socially integrated (professionaly, parentally and residentially), have to live with those customs. Therefore, a tension appears between both récrational and biological reproductive uses of city centers at night. A second section highlights the fact that both night owls and bars owners are mobilised through recreational use, the firsts by socialising one another in bars and night clubs which are duly selected ; the seconds by polarising but also managing the firsts. Sometimes, these daily mobilisations become both political and collective ones, the moment recreational and nocturnal appropriation of streets on one hand, commercial activity on the other hand, are threatened. The third section develops the link between recreational and nocturnal customs and residential mobilisations. The social division of urban centers once established, several characteristics have been highlighted so that to explain sound perceptions, such as acoustic and exposure ones, but also sociological ones. Perhaps more than the fists, the latest explains the differents ways of perceiving recreational and nocturnal sounds, the evolution throughout « cycles of life » – that is to say professional insertion and above all experience and property – being most important. This cognitive division goes with an actional one : on one hand, those who are still linked with recreational and nocturnal customs mainly get used to the noise or confront those who are responsible for their sound annoyance (mostly neighbours) ; on the other hand, those who are gradually distancing themselves from these customs do not hesitate to resort to institutions or even to engage in collective action. Eventually, a fourth section deals with the way institutions govern the night owls, the bar owners and the residents who are mobilised. After the administrative and police repression of the night owls but also the bar owners during the 2000’s in Rennes and even in Caen, after the contractualisation with the latests and the health handling of the firsts around 2010, a rupture have occurred these last few years. With increasing budgetary restrictions, bar owners seem to be considered today by the institutions more as order and health auxiliaries useful so as to restrain night owls’ deviance than as persons responsible for it. Seldom listened by institutions, residents who are mobilised are also being neutralised throughout dedicated devices. On the whole, this research shows the transition from fordist economy which considers night time as a mean to reproduce diurnal workforce to post-fordist one, in which 24/7 city has also to fulfil cognitive capitalism needs
Dahan, Jean-Jacques. « La démarche de découverte expérimentalement médiée par Cabri-Géomètre en mathématiques : un essai de formalisation à partir de l'analyse de démarches de résolutions de problèmes de boîtes noires ». Phd thesis, 2005. http://tel.archives-ouvertes.fr/tel-00356107.
Texte intégralL'analyse de la résolution d'une boîte noire particulière permet d'affiner notre modèle a priori de la démarche de découverte en y précisant le rôle de la figure (Duval), les niveaux de géométrie (praxéologies G1 et G2 de Parzysz) et leurs prolongements que nous développons (G1 et G2 informatiques), les cadres d'investigations (Millar) et la place de la preuve expérimentale (Johsua).
Les analyses des expérimentations mises en place permettent de disposer d'un modèle amélioré qui doit permettre aux enseignants d'avoir une connaissance minimale des étapes heuristiques du travail de leurs élèves, de concevoir des activités d'études et de recherches ayant des objectifs précis en liaison avec les étapes formalisées de notre modélisation et d'envisager leur possible évaluation.
Des analyses d'activités existantes avec notre grille montrent la validité du modèle étudié. Des propositions d'activités ont été construites pour favoriser l'apparition de telle ou telle phase de la recherche; elles montrent la viabilité de ce modèle dans la conception d'ingénieries didactiques générant une démarche conforme à la démarche postulée.
Hissem, Simon. « Contribution à la conception de contrôleur pour des systèmes de type boîtes noires et des systèmes à haut degré de fonctions de transfert = Contribution to the design of controller for systems of black boxes type and systems with high degree of transfer functions ». Thèse, 2019. http://depot-e.uqtr.ca/9074/1/032317586.pdf.
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