Earthquake is undoubtedly one of the greatest natural disasters that can induce serious structural damage and huge losses of properties and lives. The resulting destructive consequences not only have made structural seismic analysis and design much more important but have impelled the necessity of more realistic representation of ground motions, such as inclusion of ground motion spatial variations in earthquake modelling and seismic analysis and design of structures. Recorded seismic ground motions exhibit spatial variations in their amplitudes and phases, and the spatial variabilities have an important effect on the responses of structures extended in space, such as long span bridges. Because of the multi-parametric nature and the complexity of the problems, the development of specific design provisions on spatial variabilities of ground motions in modern seismic codes has been impeded. Eurocode 8 is currently the only seismic standard worldwide that gives a set of detailed guidelines to explicitly tackle spatial variabilities of ground motions in bridge design, providing both a simplified design scheme and an analytical approach. However, there is gap between the code-specified provisions in Eurocode 8 and the realistic representation of spatially varying ground motions (SVGM) and the corresponding stochastic vibration analysis (SVA) approaches. This study is devoted to bridge this gap on modelling of SVGM and development of SVA approaches for structures extended in space under SVGM. A complete and realistic SVGM representation approach is developed by accounting for the incoherence effect, wave-passage effect, site-response effect, ground motion nonstationarity, tridirectionality, and spectra-compatibility. This effort brings together various aspects regarding rational seismic scenarios determination, comprehensive methods of accounting for varying site effects, conditional modelling of SVGM nonstationarity, and code-specified ground motion spectra-compatibility. A comprehensive, systematic, and efficient SVA methodology is derived for long span structures under tridirectional nonstationary SVGM. An absolute-response-oriented scheme of pseudo-excitation method and an improved high precision direct integration method are proposed to reduce the enormous computational effort of conventional nonstationary SVA. A scheme accounting for tridirectional varying site-response effect is incorporated in the nonstationary SVA scheme systematically. The proposed highly efficient and accurate SVA approach is implemented and verified in a general finite element analysis platform to make it readily applicable in SVA of complex structures. Based on the proposed SVA approach, parametric studies of two practical long span bridges under SVGM are conducted. To account for spatial randomness and variability of soil properties in soil-structure interaction analysis of structures under SVGM, a meshfree-Galerkin approach is proposed within the Karhunen-Loeve expansion scheme for representation of spatial soil properties modelled as a random field. The meshfree shape functions are proposed as a set of basis functions in the Galerkin scheme to solve integral equation of Karhunen-Loeve expansion, with a proposed optimization scheme in treating the compatibility between the target and analytical covariance models. The accuracy and validity of the meshfree-Galerkin scheme are assessed and demonstrated by representation of covariance models for various homogeneous and nonhomogeneous spatial fields. The developed modelling approaches of SVGM and the derived analytical SVA approaches can be applied to provide more refined solutions for quantitatively assessing code-specified design provisions and developing new design provisions. The proposed meshfree-Galerkin approach can be used to account for spatial randomness and variability of soil properties in soil-structure interaction analysis.

The aims of the thesis were (i) to investigate the impact of repetitive low-intensity work exposure on proprioception and (ii) to examine effects of muscle stretching (especially sensory effects and effects on muscle nociception) and to relate its application to the prevention, alleviation and/or treatment of work-related neuromuscular disorders. The effects of low-intensity repetitive work on the shoulder proprioception were tested in healthy subjects. The effect of working time on the retention of subjective fatigue and their relation to changes in proprioception, and the immediate effect of stretching on shoulder proprioception were investigated. A new method to test the stretchability of the rectus femoris muscle was investigated for reliability and validity and used to assess the effects of a two-week stretching regimen on range of motion and on subjective stretch sensation. Finally, the interactions between innocuous muscle stretch and nociceptive chemical stimulation on discharge behavior of nociceptive dorsal horn neurons in the feline spinal cord were explored. The main findings were as follows: 1) The repetitive low-intensity work to fatigue diminished the shoulder proprioception; the working time as well as the retention of subjective fatigue were partly related to the extent of changed proprioception. 2) There was no effect of acute muscle stretching on the proprioception. 3) The new method for testing muscle stretchability proved valid and reliable. A two-week stretching regimen increased the tolerance to stretch torque, but the range of motion remained unchanged. 4) Half of the nociceptive dorsal horn neurons that responded to close arterial injections of bradykinin were modulated by muscle stretching applied directly after the injections. Altogether, the results give credence to the hypothesis of an involvement of sensory information distortion due to repetitive low-intensity work exposure in the development of work-related neuromuscular disorders. Increased tolerance to stretch torque may be an important mechanism in explaining improvements following stretch treatment. The spinal interactions between innocuous stretch and nociceptive muscle afferent inputs indicate a possible mechanism involved in stretching-induced pain alleviation.

Il semble maintenant établi que la majorité des étoiles se forment dans des amas (Carpenter 2000; Porras et al. 2003; Lada & Lada 2003). Comprendre l'origine et l'évolution des populations stellaires est donc l'un des plus grands défis de l'astrophysique moderne. Malheureusement, moins d'un dixième de ces amas restent gravitationellement liés au delà de quelques centaines de millions d'années (Lada & Lada 2003). L’étude des amas stellaires doit donc se faire avant leur dissolution dans la galaxie.Le projet Dynamical Analysis of Nearby Clusters (DANCe, Bouy et al. 2013), dont le travail fait partie, fournit le cadre scientifique pour l'analyse des amas proches et jeunes (NYC) dans le voisinage solaire. Les observations de l'amas ouvert des Pléiades par le projet DANCe offrent une opportunité parfaite pour le développement d'outils statistiques visant à analyser les premières phases de l'évolution des amas.L'outil statistique développé ici est un système intelligent probabiliste qui effectue une inférence bayésienne des paramètres régissant les fonctions de densité de probabilité (PDF) de la population de l'amas (PDFCP). Il a été testé avec les données photométriques et astrométriques des Pléiades du relevé DANCe. Pour éviter la subjectivité de ces choix des priors, le système intelligent les établit en utilisant l'approche hiérarchique bayésienne (BHM). Dans ce cas, les paramètres de ces distributions, qui sont également déduits des données, proviennent d'autres distributions de manière hiérarchique.Dans ce système intelligent BHM, les vraies valeurs du PDFCP sont spécifiées par des relations stochastiques et déterministes représentatives de notre connaissance des paramètres physiques de l'amas. Pour effectuer l'inférence paramétrique, la vraisemblance (compte tenu de ces valeurs réelles), tient en compte des propriétés de l'ensemble de données, en particulier son hétéroscédasticité et des objects avec des valeurs manquantes.Le BHM obtient les PDF postérieures des paramètres dans les PDFCP, en particulier celles des distributions spatiales, de mouvements propres et de luminosité, qui sont les objectifs scientifiques finaux du projet DANCe. Dans le BHM, chaque étoile du catalogue contribue aux PDF des paramètres de l'amas proportionnellement à sa probabilité d'appartenance. Ainsi, les PDFCP sont exempts de biais d'échantillonnage résultant de sélections tronquées au-dessus d'un seuil de probabilité défini plus ou moins arbitrairement.Comme produit additionnel, le BHM fournit également les PDF de la probabilité d'appartenance à l'amas pour chaque étoile du catalogue d'entrée, qui permettent d'identifier les membres probables de l'amas, et les contaminants probables du champ. La méthode a été testée avec succès sur des ensembles de données synthétiques (avec une aire sous la courbe ROC de 0,99), ce qui a permis d'estimer un taux de contamination pour les PDFCP de seulement 5,8 %.Ces nouvelles méthodes permettent d'obtenir et/ou de confirmer des résultats importants sur les propriétés astrophysiques de l'amas des Pléiades. Tout d'abord, le BHM a découvert 200 nouveaux candidats membres, qui représentent 10% de la population totale de l'amas. Les résultats sont en excellent accord (99,6% des 100 000 objets dans l'ensemble de données) avec les résultats précédents trouvés dans la littérature, ce qui fournit une validation externe importante de la méthode. Enfin, la distribution de masse des systèmes actuelle (PDSMD) est en général en bon accord avec les résultats précédents de Bouy et al. 2015, mais présente l'avantage inestimable d'avoir des incertitudes beaucoup plus robustes que celles des méthodes précédentes.Ainsi, en améliorant la modélisation de l'ensemble de données et en éliminant les restrictions inutiles ou les hypothèses simplificatrices, le nouveau système intelligent, développé et testé dans le présent travail, représente l'état de l'art pour l'analyse statistique des populations de NYC. / The origin and evolution of stellar populations is one of the greatest challenges in modern astrophysics. It is known that the majority of the stars has its origin in stellar clusters (Carpenter 2000; Porras et al. 2003; Lada & Lada 2003). However, only less than one tenth of these clusters remains bounded after the first few hundred million years (Lada & Lada 2003). Ergo, the understanding of the origin and evolution of stars demands meticulous analyses of stellar clusters in these crucial ages.The project Dynamical Analysis of Nearby Clusters (DANCe, Bouy et al. 2013), from which the present work is part of, provides the scientific framework for the analysis of Nearby Young Clusters (NYC) in the solar neighbourhood (< 500 pc). The DANCe carefully designed observations of the well known Pleiades cluster provide the perfect case study for the development and testing of statistical tools aiming at the analysis of the early phases of cluster evolution.The statistical tool developed here is a probabilistic intelligent system that performs Bayesian inference for the parameters governing the probability density functions (PDFs) of the cluster population (PDFCP). It has been benchmarked with the Pleiades photometric and astrometric data of the DANCe survey. As any Bayesian framework, it requires the setting up of priors. To avoid the subjectivity of these, the intelligent system establish them using the Bayesian Hierarchical Model (BHM) approach. In it, the parameters of prior distributions, which are also inferred from the data, are drawn from other distributions in a hierarchical way.In this BHM intelligent system, the true values of the PDFCP are specified by stochastic and deterministic relations representing the state of knowledge of the NYC. To perform the parametric inference, the likelihood of the data, given these true values, accounts for the properties of the data set, especially its heteroscedasticity and missing value objects. By properly accounting for these properties, the intelligent system: i) Increases the size of the data set, with respect to previous studies working exclusively on fully observed objects, and ii) Avoids biases associated to fully observed data sets, and restrictions to low-uncertainty objects (sigma-clipping procedures).The BHM returns the posterior PDFs of the parameters in the PDFCPs, particularly of the spatial, proper motions and luminosity distributions. In the BHM each object in the data set contributes to the PDFs of the parameters proportionally to its likelihood. Thus, the PDFCPs are free of biases resulting from typical high membership probability selections (sampling bias).As a by-product, the BHM also gives the PDFs of the cluster membership probability for each object in the data set. These PDFs together with an optimal probability classification threshold, which is obtained from synthetic data sets, allow the classification of objects into cluster and field populations. This by-product classifier shows excellent results when applied on synthetic data sets (with an area under the ROC curve of 0.99). From the analysis of synthetic data sets, the expected value of the contamination rate for the PDFCPs is 5.8 ± 0.2%.The following are the most important astrophysical results of the BHM applied tothe Pleiades cluster. First, used as a classifier, it finds ∼ 200 new candidate members, representing 10% new discoveries. Nevertheless, it shows outstanding agreement (99.6% of the 105 objects in the data set) with previous results from the literature. Second, the derived present day system mass distribution (PDSMD) is in general agreement with the previous results of Bouy et al. (2015).Thus, by better modelling the data set and eliminating unnecessary restrictions to it, the new intelligent system, developed and tested in the present work, represents the state of the art for the statistical analysis of NYC populations.

La spectrométrie de masse fournit deux types d’informations : la masse moléculaire des molécules présentes dans un mélange, en une première expérience (MS), puis leurs structures après isolation suivie de fragmentation, obtenues une à une (MS/MS). La spectrométrie de masse FT-ICR bidimensionnelle permet d’obtenir toutes ces informations en une seule expérience, sans isolation, quelle que soit la complexité de l’échantillon. Le prix à payer est une faible résolution dans la dimension indirecte, pouvant être améliorée par une augmentation du temps d’analyse, mais qui semblait limiter cette technique à une simple curiosité scientifique.Le premier objectif est d’implémenter l’échantillonnage non uniforme (NUS) en FT-ICR MS 2D. Cette technique consiste en l’acquisition aléatoire du même nombre de points dans la dimension indirecte que lors d’une acquisition uniforme, mais sur une plage de t1max plus grande. Les points manquants sont ensuite reconstruits par des algorithmes, entrainant une augmentation significative de la résolution du signal sans perte de temps sur le spectromètre. La première étape est de créer un algorithme générant un échantillonnage aléatoire de distribution uniforme pour une couverture optimale de la plage de t1max. Les algorithmes de reconstruction ayant des difficultés à reconstituer des signaux de faible intensité quand le nombre de points non échantillonnés augmente, la deuxième étape est de déterminer le facteur de sous-échantillonnage optimal afin d’obtenir le bon compromis entre résolution et signal-sur-bruit. La troisième étape est de réaliser des spectres MS/MS ayant des massifs isotopiques corrects pour des fragments produits à partir des isotopes les plus lourds.Le deuxième objectif est de décrire le comportement des ions dans la cellule ICR en fonction des impulsions RF utilisées à partir des équations de Lorentz. Dans une première partie, le but est d’établir les équations qui régissent le mouvement des ions précurseurs jusqu’à leur détection. Ensuite, il s’agit d’introduire la fragmentation et de déterminer les solutions analytiques décrivant le mouvement des fragments. La dernière étape est de simuler le comportement des ions précurseurs tout au long de la séquence d’impulsions ainsi que celui des nuages de fragments, de leur formation à leur détection. / Mass spectrometry provides two kinds of information: the molecular mass of molecules present in a mixture, obtained all at once (MS), and structure through isolation and fragmentation, obtained one by one (MS/MS). Two-dimensional FT-ICR MS allows simultaneous parallel acquisition of structural information without isolation, regardless of the number of molecules. Nevertheless, the low resolution in the indirect dimension, which could be improved by increasing the acquisition time, seemed to limit this method to a simple curiosity. The first objective is to implement non-uniform-sampling (NUS) in 2D FT-ICR MS. This method consist in the random acquisition of the same number of points in the indirect dimension as in uniform acquisition, but over a wider t1max range. Processing algorithms then reconstruct skipped points, and the result is an increase of signal resolution without wasting analysis time. The first step is to create an algorithm that can generate random sampling with a uniform distribution for an optimal coverage of the t1max range. Processing algorithms may have trouble to reconstruct small peaks when the number of skipped points increases. The second step is to choose the under-sampling ratio for the best compromise between the gain in resolution and the signal-to-noise ratio. The third and last step is to obtain MS/MS spectra with corrects isotopic patterns for fragments produced from heavy isotopes. The second objective is to improve the understanding of ion motions in ICR cells depending on the RF pulses by using Lorentz equations. The first goal is to determine the equations governing precursors motions until their detection. Then the fragmentation will be introduced and analytical solutions describing fragments motions will be established. The last step is to simulate the trajectories of precursors throughout the entire pulse sequence as well as the behavior of fragments clouds, from their formation to detection.

EcoR124I is a Type I restrictionmodification (RM) enzyme and as such forms multifunctional pentameric complexes with DNA cleavage and ATP-dependent DNA translocation activities located on the motor subunit HsdR. When non-methylated invading DNA is recognized by the complex, two HsdR endonuclease/motor subunits start to translocate dsDNA without strand separation activity up to thousands base pairs towards the stationary enzyme while consuming ~1 molecule of ATP per base pair advanced. Whenever translocation is stalled the HsdR subunits cleave the dsDNA nonspecifically far from recognition site. The X-ray crystal structure of HsdR of EcoR124I bound to ATP gave a first insight of structural/functional correlation in the HsdR subunit. The four domains within the subunit were found to be in a square planer arrangement. Computational modeling including molecular dynamics in combination with crystallography, point mutations, in vivo and in vitro assays reveals how interactions between these four domains contribute to ATP-dependent DNA translocation, DNA cleavage or inter-domain communication between the translocase and endonuclease activities.

Une question fondamentale qui surgit dans le cadre de l’analyse probabiliste du risque sismique est le choix des indicateurs de nocivité des signaux sismiques. En plus de réduire la variabilité de la réponse structurelle (ou non structurelle),un indicateur amélioré (i.e. capable de mieux capturer les caractéristiques de nocivité des mouvements sismiques, aussi bien que l’alea sismique) fournit des critères moins stricts pour la sélection des signaux sismiques.Deux nouveaux indicateurs sont proposés dans cette étude: le premier, nommé ASAR (i.e. Relative Average Spectral Acceleration), est conçu pour la prévision de la demande structurelle, le second, nommé E-ASAR (i.e.Equipment Relative Average Spectral Acceleration), vise à prévoir la demande des composants non structuraux. Les performances des indicateurs proposés sont comparées avec celles des indicateurs de la littérature, sur la base de: a)milliers d’enregistrements sismiques ; b) analyses numériques conduites avec des modèles représentants différents types de bâtiments; et c) analyses statistiques rigoureuses des résultats. Selon l'étude comparative, les indicateurs développés s'avèrent être plus “efficaces” que les indicateurs couramment utilisés. D'ailleurs, l’ASAR et l’E-ASAR ont montré au propre la caractéristique de la “suffisance” en ce qui concerne la magnitude, la distance source-site, et le type de sol (VS30). De plus, les deux indicateurs originaux peuvent être calculés simplement avec la connaissance de la fréquence fondamentale du bâtiment. Cette caractéristique rend l’ASAR et l’E-ASAR facilement exploitables dans les études probabilistes d’alea sismique.Par conséquent, en raison de leur efficacité, suffisance, robustesse et formulation simple, l’ASAR et l’E-ASAR peuvent être considérés comme des candidats prometteurs pour la définition de l’alea sismique dans les cadres de l'analyse probabiliste et déterministe du risque sismique. / A fundamental issue that arises in the framework of Probabilistic Seismic Risk Analysis is the choice of groundmotion Intensity Measures (IMs). In addition to reducing record-to-record variability, an improved IM (i.e. one able tobetter capture the damaging features of a record, as well as the site hazard) provides criteria for selecting input groundmotions to loosen restrictions.Two new structure-specific IMs are proposed in this study: the first, namely ASAR (i.e. Relative Average SpectralAcceleration), is conceived for Structural demand prediction, the second namely, E-ASAR (i.e. Equipment-RelativeAverage Spectral Acceleration), aims to predict Non-Structural components acceleration demand. The performance ofthe proposed IMs are compared with the ones of current IMs, based on: a) a large dataset of thousands recordedearthquake ground motions; b) numerical analyses conducted with state-of-the-art FE models, representing actualload-bearing walls and frame structures, and validated against experimental tests; and c) systematic statistical analysesof the results. According to the comparative study, the introduced IMs prove to be considerably more “efficient” withrespect to the IMs currently used. Likewise, both ASAR and E-ASAR have shown to own the characteristic of“sufficiency” with respect to magnitude, source-to-site distance and soil-type (Vs30). Furthermore, both the introducedIMs possess the valuable characteristics to need (in order to be computed) merely the knowledge of the building’sfundamental frequency, exactly as it is for the wide-spread spectral acceleration Spa(f1). This key characteristic makesboth ASAR and E-ASAR easily exploitable in Probabilistic Seismic Hazard Analysis.Therefore, due to their proven efficiency, sufficiency, robustness and applicable formulation, both ASAR and EASARcan be considered as worthy candidates for defining seismic hazard within the frameworks of both Probabilisticand Deterministic Seismic Risk Analysis.

Nas duas últimas décadas, houve um enorme aumento no número de estruturas proteicas resolvidas, e entre elas há uma variedade imensa de proteínas com mais de uma conformação observada. Essa quantidade incontestável de dados experimentais corroboram a hipótese de que cada proteína exista num espaço conformacional próprio, onde ela possa adotar inúmeras conformações, umas mais distintas ou estáveis que outras. Essas conformações estão distribuídas nesse espaço de acordo com sua energia potencial, que pode ser definida como uma superfície cheia de rugosidades, poços e barreiras energéticas. Duas conformações distantes nesse espaço são muito diferentes entre si, enquanto que duas conformações próximas são mais semelhantes. Da mesma forma, se distinguem os movimentos necessários para passar de uma conformação à outra. Para uma proteína passar de um estado a outro, geralmente identificados com grandes mudanças conformacionais, é necessário um movimento coletivo. Por ser de grande amplitude, esse tipo de movimento ocorre com baixa frequência, e dificilmente é observado em simulações clássicas de dinâmica molecular. Assim, existem métodos dedicados à obtenção destes movimentos, como a análise de modos normais, os modelos de redes elásticas e a análise de componentes principais. Neste trabalho, adaptamos o método de transformada de Fourier para recuperar modos harmônicos que compõem uma trajetória simulada suficientemente longa para analisar três proteínas distintas quanto a seus movimentos biológicos de importância funcional. Uma é a DEA, cuja simetria hexagonal observamos influenciar nos modos coletivos e na transição entre estados. Outra é a MosR, que simulamos em seus dois estados diferentes, oxidado ou reduzido, para encontrar como a oxidação é capaz de impedir os movimentos coletivos que levam à conformação ligada ao DNA. Nestas duas proteínas, observamos que nenhum modo por si só é responsável pela transição entre as conformações experimentais, mas que eles dependem de outros modos ou outras mudanças conformacionais ocorrendo de forma combinada. A terceira proteína analisada é um regulador transcricional, assim como a MosR, a ElrR, cuja estrutura é conhecida somente na forma apo. Neste trabalho, construímos modelos da ElrR ligada ao DNA pela combinação linear de modos harmônicos para modelar um possível ligante na nova conformação do sítio alostérico. As amplitudes usadas nessa combinação foram obtidas pelo método de mínimos quadrados, visando minimizar o desvio em relação somente às coordenadas que as hélices de reconhecimento devem apresentar para se ligar ao sítio de DNA. Este prognóstico foi feito pela análise metódica das estruturas de 27 reguladores transcricionais, homodiméricos com o motivo HTH, em complexo com DNA. Essa análise também nos permitiu descrever a estereoquímica do encaixe das hélices de reconhecimento nos sulcos maiores do DNA com novos parâmetros geométricos, intimamente relacionados com a simetria do complexo, com a sequência de resíduos das hélices de reconhecimento e com a sequência de bases do sítio de DNA, de forma a auxiliar na modelagem de novos complexos. / There was an enormous increase in the deposited protein structures in the past two decades, among them there is a great variety of proteins with more than one observed conformation. This undenieble amount of experimental data ratify the hypothesis that each protein posseses its own conformational space, where it can adopt countless conformations, some more distinct or stable than others. These conformations are distributed in the space according to its potential energy, which maybe defined as a rough landscape fulled with energetic wells and barriers. Two conformations lying apart from each other in this landscape do not carry much resemblances, while neighbouring conformations are very similar. The motions required to get one conformation to another are just as distinguishable. There must be a collective motion inbetween two states of a protein, commonly characterized by large conformation changes. This type of motion is related to large amplitudes and low frequencies, thus it is hardly seen in classical molecular dynamics simulations. Therefore, there are dedicated methods to obtain these motions, as normal modes analysis, elastic network models and essential dynamics. In this work we adapted the method of Fourier transform filtering to retrieve harmonic modes that compose a simulated trajectory and thus analise the biological motions with functional importance of three distinct proteins. One is DEA, which hexagonal symmetry was observed to affect its collective motions and the transition between biological states. Another protein is MosR, which we simulated in two different states, oxidized or reduced, to learn how the formation of a disulphide bridge is able to preclude the collective motions that lead to a DNA-binding conformation. With these two proteins we observed that no mode by itself is responsible for the transition between experimental conformations, and they actually depend on other conformational changes occurring in a combined manner. The third protein that we analised, ElrR, is a transcriptional regulator, like MosR, which structure is known only on its apo form. Hence in this work we built models of ElrR bound to DNA by the linear combination of harmonic modes aiming to model a ligand that would fit in the allosteric site upon the conformational changes driven by the collective motions. The amplitudes we used in this method were calculated by the least square method to minimize the deviation to the positions of the recognition helices when bound to the DNA. This prognostic of the target position of the recognition helices was made upon the methodical analysis of 27 structures of homodimeric transcriptional regulators, that present the Helix-Turn-Helix motif, complexed with DNA. This approach allowed us to describe the stereochemical fitting of the recognition helices into the DNA major grooves with new geometrical parameters intimatelly related to the symmetry of the complex, the residue sequence of the recognition helices and the base sequence of the DNA site, providing thus support to model new complexes.

L’interaction Humain-Robot est un domaine de recherche en pleine expansion parmi la communauté robotique. De par sa nature il réunit des chercheurs venant de domaines variés, tels que psychologie, sociologie et, bien entendu, robotique. Ensemble, ils définissent et dessinent les robots avec lesquels nous interagirons dans notre quotidien.Comme humains et robots commencent à travailler en environnement partagés, la diversité des tâches qu’ils peuvent accomplir augmente drastiquement. Cela créé de nombreux défis et questions qu’il nous faut adresser, en terme de sécurité et d’acceptation des systèmes robotiques.L’être humain a des besoins et attentes bien spécifiques qui ne peuvent être occultés lors de la conception des interactions robotiques. D’une certaine manière, il existe un besoin fort pour l’émergence d’une véritable interaction humain-robot ergonomique.Au cours de cette thèse, nous avons mis en place des méthodes pour inclure des critères ergonomiques et humains dans les algorithmes de prise de décisions, afin d’automatiser le processus de génération d’une interaction ergonomique. Les solutions que nous proposons se basent sur l’utilisation de fonctions de coût encapsulant les besoins humains et permettent d’optimiser les mouvements du robot et le choix des actions. Nous avons ensuite appliqué cette méthode à deux problèmes courants d’interaction humain-robot.Dans un premier temps, nous avons proposé une technique pour améliorer la lisibilité des mouvements du robot afin d’arriver à une meilleure compréhension des ses intentions. Notre approche ne requiert pas de modéliser le concept de lisibilité de mouvements mais pénalise les trajectoires qui amènent à une interprétation erronée ou tardive des intentions du robot durant l’accomplissement d’une tâche partagée. Au cours de plusieurs études utilisateurs nous avons observé un gain substantiel en terme de temps de prédiction et une réduction des erreurs d’interprétation.Puis, nous nous sommes attelés au problème du choix des actions et des mouvements qui vont maximiser l’ergonomie physique du partenaire humain. En utilisant une mesure d’ergonomie des postures humaines, nous simulons les actions et mouvements du robot et de l’humain pour accomplir une tâche donnée, tout en évitant les situations où l’humain serait dans une posture de travail à risque. Les études utilisateurs menées montrent que notre méthode conduit à des postures de travail plus sûr et à une interaction perçue comme étant meilleure. / Human-Robot Interaction (HRI) is a growing field in the robotic community. By its very nature it brings together researchers from various domains including psychology, sociology and obviously robotics who are shaping and designing the robots people will interact with ona daily basis. As human and robots starts working in a shared environment, the diversity of tasks theycan accomplish together is rapidly increasing. This creates challenges and raises concerns tobe addressed in terms of safety and acceptance of the robotic systems. Human beings havespecific needs and expectations that have to be taken into account when designing robotic interactions. In a sense, there is a strong need for a truly ergonomic human-robot interaction.In this thesis, we propose methods to include ergonomics and human factors in the motions and decisions planning algorithms, to automatize this process of generating an ergonomicinteraction. The solutions we propose make use of cost functions that encapsulate the humanneeds and enable the optimization of the robot’s motions and choices of actions. We haveapplied our method to two common problems of human-robot interaction.First, we propose a method to increase the legibility of the robot motions to achieve abetter understanding of its intentions. Our approach does not require modeling the conceptof legible motions but penalizes the trajectories that leads to late or mispredictions of therobot’s intentions during a live execution of a shared task. In several user studies we achievesubstantial gains in terms of prediction time and reduced interpretation errors.Second, we tackle the problem of choosing actions and planning motions that maximize thephysical ergonomics on the human side. Using a well-accepted ergonomic evaluation functionof human postures, we simulate the actions and motions of both the human and the robot,to accomplish a specific task, while avoiding situations where the human could be at risk interms of working posture. The conducted user studies show that our method leads to saferworking postures and a better perceived interaction.

L'Afrique de l'est représente un site idéal pour étudier les mécanismes à l'origine de la mise en place et du maintien d'une région en extension. Le rift est africain marque la séparation intra-continentale entre les plaques Nubie et Somalie, dans un contexte principalement tectonique dominé par l'activité de failles normales, alors qu'au niveau des rides de la Mer Rouge et d'Aden l'Arabie se détache du couple de plaques Somalie/Nubie dans un contexte principalement magmatique avec accrétion océanique. Ces trois frontières de plaques se rejoignent au niveau de la dépression Afar. Elles forment une jonction triple qui correspond à une zone de transition entre une lithosphère continentale étirée et des axes d'accrétion océaniques où la présence du point chaud sous la lithosphère a fortement influencé l'extension. À partir de mesures et de traitements géodésiques (GPS, InSAR), l'objectif de ce travail de thèse est de décrire les mouvements actuels de la surface dans cette région de l'Afrique de l'est, où trois plaques s'éloignent les unes des autres, et où les différentes frontières de plaques sont à des stades différents de rifting. L'analyse de la déformation actuelle permet de préciser la dynamique des zones d'extension à court terme, en tenant compte de leur stade d'évolution et notamment des variations de l'activité magmatique et de l'activité sismique. Ainsi trois études ont été menées à des échelles spatiales différentes. La première porte sur l'ensemble du REA (3000 km), la seconde sur la partie centrale de la dépression Afar où se localise la jonction triple (quelques centaines de km), et la troisième sur le rift d'Asal Ghoubbet à Djibouti (quelques dizaines de km). / Eastern Africa is a natural laboratory for investigating rifting and break-up. Along the East African Rift, the divergence between Nubia and Somalia plates is accommodated within a mainly tectonic framework dominated by active normal faulting. While Arabia plate moves apart from the African plate couple at the Red Sea and Aden Ridges within a mainly magmatic framework with seafloor spreading. These three plate boundaries meet in Afar Depression forming a triple junction, which correspond to a transition zone between stretched continental lithosphere and oceanic spreading axes, where the role of the mantle plume impacts is determinant. In this thesis, current deformation of the Earth's surface is monitored using geodetics data (GPS, InSAR), in the East African zone where three plates are splitting apart and where the different boundaries encompass areas in all stages of rifting. The current deformation analysis allows clarify extension zone dynamics at short term, taking into account their stage of rifting evolution and especially the variations of magmatic and/or seismic activity. Three studies were carried out at three different spatial scales. The first one considers the whole East African Rift (3000 km), the second one is about the central part of the Afar Depression where the triple junction is situated (a few hundreds of km) and the third focuses on the Asal-Ghoubbet rift in Djibouti (a few tens of km).

Le comportement nonlinéaire des sols observé lors des mouvements sismiques forts est maintenant bien admis et le déploiement des puits accélérométriques a permis des analyses détaillées de la propagation des ondes ainsi qu’une évaluation quantitative des paramètres physiques tels que la vitesse de cisaillement et de compression des ondes et les facteurs d’amortissements en fonction de la déformation. En dépit du nombre grandissant d’études sur ce phénomène, sa connaissance est encore récente et les recherches sur les données de puits accélérométriques restent une étape importante vers la compréhension du comportement complexe in-situ des sédiments soumis à des mouvements sismiques forts.L’objectif de ces travaux est triple. Premièrement, un code d’inversion par algorithme génétique est développé afin d’inverser des données de puits accélérométriques via la théorie des matrices de propagation de Thomson-Haskell. Cette technique nous permet dans un premier temps de valider la structure en une dimension (1D) (e.g., vitesse des ondes de cisaillement, facteurs d’ amortissements) d’un puits accélérométrique dans le domaine linéaire et dans un second temps de mettre en évidence de manière quantitative le comportement nonlinéaire des sédiments lors du séisme de Fukuoka, 2005, Japon. Deuxièmement, les résultats de l’inversion sont utilisés pour tester des lois de comportement simples et avancées en utilisant la Méthode des éléments Finis. Les résultats montrent clairement que l’hypothèse bi-linéaire de la loi de comportement simple produit des séries temporelles non réalistes en vitesse et en accélération. L’utilisation d’une loi de comportement avancée mène à de meilleurs résultats, cependant, le nombre de paramètres ajustables pour obtenir des résultats consistants avec l’observation est un obstable inévitable. Troisièmement, afin d’étendre l’étude des effets de site à des dimensions supérieures, des codes 2D et 3D de la Méthode en éléments Spectraux sont développés et validés en comparant leurs résultats dans le domaine linéaire avec ceux obtenus théoriquement ou via d’autres méthodes numériques. / Nonlinear behavior of soft soils observed during strong ground motions isnow well established and the deployment of vertical arrays (i.e., boreholestations) has contributed to detailed wave propagation analyses and the assessmentfor quantitative physical parameters such as shear-wave velocity,pressure-wave velocity and damping factors with respect to shear strain levels.Despite the growing number of studies on this phenomena, its knowledgeis still recent and research on borehole station data remains an importantstep toward the understanding of the complex in-situ behavior of soft sedimentssubjected to strong ground motions.The purpose of this work is threefold. First, an inversion code by geneticalgorithm is developed in order to inverse borehole stations data viathe Thomson-Haskell propagator matrix method. This technique allows usto validate the one-dimensional (1D) structure (e.g., shear-wave velocity,damping factors) of a borehole in the linear elastic domain and to showquantitative evidence of the nonlinear behavior of the soft sediments duringthe 2005 Fukuoka Prefecture western offshore earthquake, Japan. Second,the results of the inversion are used in order to test simple and advancedconstitutive laws using the Finite Elements Method. The results clearlyshow that the bi-linear assumption of the simple constitutive law producesunrealistic velocity and acceleration time histories. The use of the advancedconstitutive law leads to better results, however, the number of parametersto be tuned in order to obtain results consistent with the observation is anunavoidable obstacle. Third, in order to extend the study of site effects tohigher dimensions, 2D and 3D codes of the very efficient Spectral ElementsMethod are developed and validated by comparing their results in the lineardomain with those obtained theoretically or with other numerical methods.