Background - Welcome to the 2010’s and its visual information culture informing about the century-old ideal of thinness, by sending (almost) exclusively thin bodies down the runway of Paris Fashion Week (PFW). This, while at the same time the academia and mass media are repeatedly articulating the necessity of a more ethical aesthetic within the fashion industry, while the argument that “thinness sells” lack empirical support, while measures are taken around Europe to discourage media bias and encourage healthy bodies walking the, and while the body positivity movement – applauding the diversity of body types – is on the rise in the Western society. Problem - How can it be explained that PFW, as an event organized to communicate the latest trends, and as an institution of a concept that thrives on change, is being stuck in an inertia of thin models? The purpose of this qualitative study is to explore the explanations for the idealization of thin bodies in regard to female runway models, to be found in visual representations of PFW. Examining the paradox of the idealization of thin bodies has the potential to reveal the measures necessary to establish practices of ethical representation in the realm of PFW. Method - The search for explanations to the inertia of the thin ideal on the runways of PFW is based upon a qualitative research design and a method of semi-structured interviews. The sample consisted of fourteen people involved in the event of PFW. It is framed within three theoretical perspectives: the trickle-down, trickle-across and trickle-up theories – associated with authors such as Simmel (1957), King (1963) and Blumer (1969a; 1969b); a theoretical view of the relation between fashion, clothes and the body provided by Barnard (2014) and, lastly, the Organizational Ecology Theory presented by Hannan and Freeman (1977; 1989). Findings - The findings suggest that the inertia of the thin ideal on the runways of PFW is explained by the thin body not only being part of a long history and tradition of creating and showing fashion, but also being dressed in aesthetic value. At the same time, the explanations to the idealization, or inertia, of thin bodies on PFW are found to be multiple as well as paradoxical, a conclusion serving as an explanation in itself. Conclusion – It is difficult to point out the explanation to the inertia of the thin ideal – both in terms of factors and actors – not at least due to the explanations stemming from both social and cultural as well as economic aspects of fashion. As a consequence, every actor part the fashion industry need to understand the effects as well as the extent of idealization of thin bodies, and start to realize that public health is more important than profits.

Les activités motrices de la vie quotidienne ou sportive se caractérisent par des mouvements de rotations complexes 3D des membres supérieurs pouvant s’effectuer autour d’axes de rotation distincts (i) articulaires (ii) d’inertie ou (iii) passant par le centre de masse du bras, chacun relevant de référentiels distincts. Une étude récente a montré que selon les contraintes de vitesse, un changement d’axe de rotation s’opère dans le cadre de l’exécution d’un mouvement simple de rotation du bras par rapport au tronc (Isableu et al., 2009). Dans ce cadre, l’objectif de la thèse a été de compléter cette première analyse et d’évaluer la robustesse de l’hypothèse selon laquelle les axes autour desquels s’organise le mouvement dépendent de la vitesse du mouvement et des contraintes liées à la tâche en général. L’hypothèse formulée est que l’axe correspondant à l’inertie minimum verra sa variabilité diminuée avec des vitesses qui augmentent par rapport à un axe lié au centre de masse (épaule-centre de masse du membre supérieur) ou géométrique (axe-épaule–coude). Cette étude s’effectue en considérant des mouvements « simples » et plus complexes incluant des gestes sportifs. Ainsi, les études effectuées ont porté sur l’influence des contraintes liées à la tâche et leur incidence sur le choix des axes de rotation. Tout d'abord le rôle de l'instruction initiale est testé. Deuxièmement, la variabilité de l'axe d’inertie minimum est évaluée au cours d'une tâche de précision. Troisièmement, l’hypothèse est testée dans le cadre d’une tâche d’interception qui implique des contraintes de temps. Enfin, nous avons testé le rôle des axes lors de gestes complexes, à grande vitesse, notamment lors de lancer à bras cassé et lors du service au tennis. Les résultats obtenus permettent de discuter l’hypothèse de l’importance de l’axe d’inertie minimum lors de l’exécution de mouvements volontaires du membre supérieur. / Motor activities of daily life or sports are characterized by complex 3D rotational movements of the upper limbs can be done around distinct axes of rotation (i) joint (ii) inertia or (iii) through the center mass of arms, each under separate repositories. A recent study showed that within the constraints of speed, a change of axis of rotation occurs in the context of the implementation of a simple rotation of the arm relative to the trunk (Isableu et al., 2009) . In this context, the aim of the thesis was to complete this first analysis to evaluate the robustness of the assumption that the axes around which organizes the movement depends on the speed of motion and the constraints task in general. The assumption is that the axis corresponding to the minimum inertia reduced variability seen with speeds which increase with respect to a center axis associated with the mass (shoulder mass center of the upper limb) and geometric (pin-shoulder elbow). This study is done by considering "simple" and complex athletic movements including movements. Thus, studies have focused on the influence of the task constraints and their impact on the choice of axes of rotation. Firstly the role of initial instruction is tested. Secondly, the variability of the axis of minimum inertia is estimated in a precise task. Thirdly, the hypothesis is tested in an interception task that involves time constraints. Finally, we tested the role of axes in complex gestures, high speed, especially during launch and broken arm during the tennis serve. The results are used to discuss the hypothesis of the importance of the axis of minimum inertia during the execution of voluntary movements of the upper limb.

<p>This thesis investigates the statistical properties of preliminary test estimators of linear models with normally distributed errors. Specifically, we derive exact expressions for the mean, variance and quadratic risk (i.e. the Mean Square Error) of estimators whose form are determined by the outcome of a statistical test. In the process, some new results on the moments of truncated linear or quadratic forms in normal vectors are established.</p><p>In the first paper (Paper I), we consider the estimation of the vector of regression coefficients under a model selection procedure where it is assumed that the analyst chooses between two nested linear models by some of the standard model selection criteria. This is shown to be equivalent to estimation under a preliminary test of some linear restrictions on the vector of regression coefficients. The main contribution of Paper I compared to earlier research is the generality of the form of the test statistic; we only assume it to be a quadratic form in the (translated) observation vector. Paper II paper deals with the estimation of the regression coefficients under a preliminary test for homoscedasticity of the error variances. In Paper III, we investigate the statistical properties of estimators, truncated at zero, of variance components in linear models with random effects. Paper IV establishes some new results on the moments of truncated linear and/or quadratic forms in normally distributed vectors. These results are used in Papers I-III. In Paper V we study some algebraic properties of matrices that occur in the comparison of two nested models. Specifically we derive an expression for the inertia (the number of positive, negative and zero eigenvalues) of this type of matrices.</p>

This thesis investigates the statistical properties of preliminary test estimators of linear models with normally distributed errors. Specifically, we derive exact expressions for the mean, variance and quadratic risk (i.e. the Mean Square Error) of estimators whose form are determined by the outcome of a statistical test. In the process, some new results on the moments of truncated linear or quadratic forms in normal vectors are established. In the first paper (Paper I), we consider the estimation of the vector of regression coefficients under a model selection procedure where it is assumed that the analyst chooses between two nested linear models by some of the standard model selection criteria. This is shown to be equivalent to estimation under a preliminary test of some linear restrictions on the vector of regression coefficients. The main contribution of Paper I compared to earlier research is the generality of the form of the test statistic; we only assume it to be a quadratic form in the (translated) observation vector. Paper II paper deals with the estimation of the regression coefficients under a preliminary test for homoscedasticity of the error variances. In Paper III, we investigate the statistical properties of estimators, truncated at zero, of variance components in linear models with random effects. Paper IV establishes some new results on the moments of truncated linear and/or quadratic forms in normally distributed vectors. These results are used in Papers I-III. In Paper V we study some algebraic properties of matrices that occur in the comparison of two nested models. Specifically we derive an expression for the inertia (the number of positive, negative and zero eigenvalues) of this type of matrices.

The thesis parts from the view that statistics starts with data, and starts by introducing the data sets studied: marine benthic species counts and chemical measurements made at a set of sites in the Norwegian Ekofisk oil field, with replicates and annually repeated. An introductory chapter details the sampling procedure and shows with reliability calculations that the (transformed) chemical variables have excellent reliability, whereas the biological variables have poor reliability, except for a small subset of abundant species. Transformed chemical variables are shown to be approximately normal. Bootstrap methods are used to assess whether the biological variables follow a Poisson distribution, and lead to the conclusion that the Poisson distribution must be rejected, except for rare species. A separate chapter details more work on the distribution of the species variables: truncated and zero-inflated Poisson distributions as well as Poisson mixtures are used in order to account for sparseness and overdispersion. Species are thought to respond to environmental variables, and regressions of the abundance of a few selected species onto chemical variables are reported. For rare species, logistic regression and Poisson regression are the tools considered, though there are problems of overdispersion. For abundant species, random coefficient models are needed in order to cope with intraclass correlation. The environmental variables, mainly heavy metals, are highly correlated, leading to multicollinearity problems. The next chapters use a multivariate approach, where all species data is now treated simultaneously. The theory of correspondence analysis is reviewed, and some theoretical results on this method are reported (bounds for singular values, centring matrices). An applied chapter discusses the correspondence analysis of the species data in detail, detects outliers, addresses stability issues, and considers different ways of stacking data matrices to obtain an integrated analysis of several years of data, and to decompose variation into a within-sites and between-sites component. More than 40 % of the total inertia is due to variation within stations. Principal components analysis is used to analyse the set of chemical variables. Attempts are made to integrate the analysis of the biological and chemical variables. A detailed theoretical development shows how continuous variables can be mapped in an optimal manner as supplementary vectors into a correspondence analysis biplot. Geometrical properties are worked out in detail, and measures for the quality of the display are given, whereas artificial data and data from the monitoring survey are used to illustrate the theory developed. The theory of display of supplementary variables in biplots is also worked out in detail for principal component analysis, with attention for the different types of scaling, and optimality of displayed correlations. A theoretical chapter follows that gives an in depth theoretical treatment of canonical correspondence analysis, (linearly constrained correspondence analysis, CCA for short) detailing many mathematical properties and aspects of this multivariate method, such as geometrical properties, biplots, use of generalized inverses, relationships with other methods, etc. Some applications of CCA to the survey data are dealt with in a separate chapter, with their interpretation and indication of the quality of the display of the different matrices involved in the analysis. Weighted principal component analysis of weighted averages is proposed as an alternative for CCA. This leads to a better display of the weighted averages of the species, and in the cases so far studied, also leads to biplots with a higher amount of explained variance for the environmental data. The thesis closes with a bibliography and outlines some suggestions for further research, such as a the generalization of canonical correlation analysis for working with singular covariance matrices, the use partial least squares methods to account for the excess of predictors, and data fusion problems to estimate missing biological data.

In an effort to achieve lighter and more economical space structures, a new patented steel composite member has been suggested and used in the construction of some steel roof structures. This special element has a sandwich construction composed of some strips of steel plates placed longitudinally along a helical wire core. The function of the helical core is to transfer the shear between the flange plates and increase the sectional inertia of the resulting composite member by keeping the flange plates at a desired distance from each other. Because of the lack of research, design engineers usually treat such elements as a solid member as if it has a full shear transfer between the flanges. However, a detailed analysis shows that this is not a valid assumption and leads to very unsafe results. In this context, the purpose of this study is to investigate the behavior of such members under axial compression and determine their effective sectional flexural rigidity by taking into account the shear deformations. This study applies an analytical investigation to a specific form of such elements with four flange plates placed symmetrically around a helical wire core. Five independent parameters of such a member are selected for this purpose. These are the spiral core and core wire diameters, the pitch of the spiral core, and the flange plate dimensions. Elements with varying combinations of the selected parameters are first analyzed in detail by finite element method, and some design charts are generated for the determination of the effective sectional properties to be used in the structural analysis and the buckling loads. For this purpose, an alternative closed-form approximate analytical solution is also suggested.

Motor activities of daily life or sports are characterized by complex 3D rotational movements of the upper limbs can be done around distinct axes of rotation (i) joint (ii) inertia or (iii) through the center mass of arms, each under separate repositories. A recent study showed that within the constraints of speed, a change of axis of rotation occurs in the context of the implementation of a simple rotation of the arm relative to the trunk (Isableu et al., 2009) . In this context, the aim of the thesis was to complete this first analysis to evaluate the robustness of the assumption that the axes around which organizes the movement depends on the speed of motion and the constraints task in general. The assumption is that the axis corresponding to the minimum inertia reduced variability seen with speeds which increase with respect to a center axis associated with the mass (shoulder mass center of the upper limb) and geometric (pin-shoulder elbow). This study is done by considering "simple" and complex athletic movements including movements. Thus, studies have focused on the influence of the task constraints and their impact on the choice of axes of rotation. Firstly the role of initial instruction is tested. Secondly, the variability of the axis of minimum inertia is estimated in a precise task. Thirdly, the hypothesis is tested in an interception task that involves time constraints. Finally, we tested the role of axes in complex gestures, high speed, especially during launch and broken arm during the tennis serve. The results are used to discuss the hypothesis of the importance of the axis of minimum inertia during the execution of voluntary movements of the upper limb.

Conventional vehicle suspensions consist of a spring and a damper, while mass is rarely used. A mass, if properly used, can also create a damping-like effect. However, a mass has only one terminal which makes it difficult to be incorporated into a suspension. In order to use a mass to achieve the damping-like effect, a two-terminal mass (TTM) has to be designed. However, most of the reported TTMs are of fixed moment of inertia (TTM-CMI), which limits the further improvement of the suspension performance and responsiveness to changes in environment and driving conditions. In this study, a TTM-based vibration absorber with variable moment of inertia (TTM-VMI) is proposed. The main component of the proposed TTM absorber contains a hydraulic-driven flywheel with sliders. The moment of inertia changes with the positions of the sliders in response to the driving conditions. The performance of the proposed TTM-VMI absorber has been analyzed via dynamics modeling and simulation and further examined by experiments. The analysis results indicate that the TTM-VMI absorber outperforms the TTM-CMI design in terms of body displacement; and ride comfort, tire grip and suspension deflection for zero and impulse inputs with comparable performance for sinusoidal input.

L'inertie thermique constitue un atout essentiel pour stocker l'énergie reçue par le bâtiment et la restituer quand cela est nécessaire : elle permet d'emmagasiner les apports gratuits issus du rayonnement solaire pour réduire les consommations énergétiques liées au chauffage en présence d'une isolation performante. En été, son association à la ventilation nocturne contribue à évacuer l'énergie stockée au cours de la journée limitant ainsi les surchauffes à l'intérieur du bâtiment. Une exploitation optimale de l'inertie passe par une sélection appropriée des matériaux de construction lors de la phase d'avant-projet et par le développement de stratégies visant à exploiter leur capacité de stockage. Les outils de simulation thermique dynamique dont on dispose permettent de modéliser de façon assez précise les transferts de chaleur dans l'enveloppe du bâtiment mais leur niveau de finesse n'est pas nécessairement adapté aux besoins des concepteurs au moment de faire les choix les plus fondamentaux. Néanmoins ils demeurent indispensables non seulement pour la validation de ces choix mais aussi pour le développement de méthodes destinées à améliorer l'exploitation de l'énergie avant de procéder à la réalisation d'un projet. Ce travail a consisté à développer une méthodologie de conception basée sur deux approches complémentaires : la première approche permet de décrire le comportement détaillé du bâtiment à l'aide d'un modèle de simulation dynamique performant développé dans la plateforme SimSPARK qu'on a eu l'occasion de comparer aux mesures expérimentales de la plateforme INCAS. La seconde est basée sur le développement de l'outil simplifié CoSPARK qui à partir de la connaissance de quelques éléments clés, permet de déterminer les caractéristiques appropriées de l'enveloppe pour favoriser la performance énergétique des bâtiments. La dernière partie de ce travail a été consacrée à l'optimisation de stratégies d'une part en activant l'inertie thermique dans le cas d'une ventilation nocturne adaptative pour l'été et d'autre part en réduisant les consommations de chauffage en hiver dans le cas d'un plancher couplé à une installation solaire en utilisant le modèle de référence SimSPARK. / Thermal inertia is a key asset to store energy received by the building and release it when needed : in winter, when used with a good insulation, it can store solar heat gains available during the day (collected via different systems) and restitute them during the night thus reducing energy consumption. In summer, building thermal mass coupled with an efficient night ventilation helps remove the energy stored during the day, which limits overheating periods inside the building during the next day. Optimal use of thermal inertia results from an appropriate selection of building materials during the preliminary design phase and the development of strategies to exploit their storage capacity. Actual thermal simulation tools allow for higher accuracy in heat transfer modeling through the building envelope. However, their level of precision is not necessarily adapted to the needs of designers during the design phase when making the first choices. Nevertheless, they remain indispensable not only for the validation of these choices but also to develop methods to improve the management of the energy prior to the completion of a project. This work aimed to develop a design methodology based on two complementary approaches : the first method uses the accurate building response evaluated using a dynamic simulation model developed in SimSPARK simulation platform that we had the opportunity to compare with experimental measurements on the INCAS platform. The second one consists on using the results of a simplified tool (CoSPARK) to determine, with only few design key elements, the appropriate characteristics of the envelope that optimize the energy performance of the building. The last part of this work exposes some strategies that help take full advantage of the thermal mass inertia ; on one hand, for summer comfort, with the use of an adaptive night ventilation control, and, on the other hand, for winter periods, by reducing heating consumption using a radiant floor heating coupled with a solar system.

Dans la plupart des entreprises de fabrication mécanique, le réglage des machines-outils est une tâche déléguée au régleur qui cherche à garantir les tolérances. Cela a pour conséquence d’augmenter le temps de réglage pour une qualité qui n’est pas au niveau souhaité. Au cours de ces six dernières années, le laboratoire SYMME a élaboré des méthodes de pilotage (Copilot-Pro®et Pilotage inertiel) pour résoudre le problème de réglage des machines-outils. Fondés sur ces deux méthodes, les travaux présentés en font une synthèse et présentent des nouvelles avancées dans le pilotage de commande numériques afin d’obtenir la meilleure qualité possible quelle que soit la complexité de la pièce. L’apport de ce travail est présenté en cinq chapitres. Le premier chapitre présente le contexte général des travaux de recherche et fait un état de l'art des travaux existants, d’une part sur le pilotage et d’autre part sur la conformité. Le pilotage consiste à réduire la variabilité autour de la cible des produits et la conformité consiste à s'assurer que la dispersion d'une caractéristique est contenue dans l'intervalle de tolérance de celle-ci. Le second chapitre revient sur les méthodes de pilotage qui consistent à établir les relations entre les caractéristiques de la pièce et les correcteurs et propose dessolutions pour améliorer le calcul de la correction en tenant compte à la fois des tolérances et des nombres de points palpés sur les surfaces de la pièce. Le troisième chapitre présente les stratégies de pilotage et met en évidence les limites des méthodes classiques de détection des situations hors contrôle qui sont la carte de contrôle de Shewhart et la carte T² de Hotelling. Le quatrième chapitre fait une synthèse des méthodologies pour faciliter le déploiement des méthodes dans l’industrie. Le cinquième chapitre présente une application expérimentale du pilotage inertiel et un témoignage de l'utilisation du pilotage matriciel dans une entreprise d'horlogerie. Une conclusion rappelle les principaux apports de ce travail. / In most mechanical manufacturing companies, setting machine-tools is a task delegated to the setter who seeks to ensure tolerances. This has the consequence of increasing the adjustment time with a quality that is not at the desired level. Over the past six years, the SYMME laboratory has developed steering methods (Copilot -Pro ® and inertial steering) to solve the problem of setting machine tools. Based on these methods, the works presented make a synthesis and presents new advances in steering of digital controls (CNC) to obtain the best quality regardless of the complexity of the part. The contribution of this workis presented in five chapters. The first chapter presents the general context of the research and makes a state of the art of existing works, on the one hand on the steering and on the other hand on the conformity. The steering consists in reducing the variability around the target products and the conformity consists in verifyingthat the dispersion of a characteristic is inside its tolerance interval. The second chapter discusses the methods of steering which consist in establishing the relationship between the characteristics of the workpiece and thetool-offsets and propose solutions to improve the calculation of the correction taking into account both tolerances and number of points probed on the surfaces of the workpiece. The third chapter presents the steering strategies and highlights the limitations of conventional methods for detecting out of control situations which are the Shewhart's control card and the T² Hotelling’s card. The fourth chapter is a synthesis of methodologies to facilitate the deployment of the methods in the industry. The fifth chapter presents an experimental application of inertial steering and a debriefing on the matrix steering used in a watch manufacturer company. Conclusion reiterates the main contributions of this work