Friction compensation is challenging but imperative for control engineers. For high-performance engineering systems, a friction-model-based controller is typically required to accommodate the nonlinearities arisen from the friction model employed. It is well known that the parameters of the friction model used in the friction compensation are nearly impossible to be accurately identified. Therefore, the objective of this research is to study the effect of these parametric uncertainties on the stability of a set-point position control system. With the above goal in mind, a variety of aspects are investigated in this work. Firstly, several common friction features and friction models are surveyed to provide background knowledge which helps select the friction model with the highest accuracy for our study. Secondly, an experimental setup is proposed and fabricated to validate the levels of accuracy given by the candidate friction models. The comparisons between the numerical and experimental results confirm that the LuGre friction model is the best approximation of the observed friction behaviours among all models selected. Moreover, a series of profound discussions addressing the relation between the candidate models’ structures and their numerical friction feature predictions are provided and followed by a summary table that recapitulates the properties of the candidate friction models. Last but not least, the state space models of the proposed setup formulated by the improved version of the LuGre model and the two controllers of interest, namely input-output linearization controller and nominal characteristic trajectory following (NCTF) controller, are derived for the stability analysis under the parametric uncertainties. Two parameters in the friction model used, σ_0 and σ_1, are perturbed for the stability analysis in which the results applying the concept of Lyapunov exponents (LEs) clearly illustrate the significant effect of the varying σ_0 and σ_1 values on the system stability. The effect of parametric uncertainties can depend quite significantly on the incorporated controller, and the stability results obtained here are applicable to the design and analysis of other systems that are inherently similar to our setup. The stability analysis conducted is this work is recommended for other control systems to avoid unwanted qualitative behaviours under parametric perturbations. / October 2016

À partir d'une approche basée sur l'étude d'évènements de submersion passés et d'épisodes observés durant ce travail, l'objectif de cette thèse était de mieux comprendre les processus atmosphériques, météo-marins et hydro-sédimentaires qui interviennent lors des submersions marines sur les côtes bretonnes. Dans un premier temps, tous les épisodes de submersions marines qui ont eu lieu depuis 1960 en Bretagne sont recensés puis analysés à une échelle régionale afin de cibler les situations atmosphériques considérées comme " à risque ". L'analyse des conditions synoptiques durant ces épisodes passés montre que la position du centre dépressionnaire et le gradient de pression au moment des pleines mers, jouent un rôle essentiel dans la localisation des secteurs submergés. Le gradient de pression s'avère être l'élément fondamental car il détermine l'ensemble des paramètres qui rentrent en compte dans l'élévation exceptionnelle du niveau d'eau à la côte. L'analyse de l'évolution de ces situations atmosphériques depuis les cinquante dernières années indique une augmentation des situations à fort gradient de pression de sud-ouest et une baisse des épisodes de nord-ouest et de nord-est. Dans un deuxième temps, l'étude des processus météo-marins à l'échelle locale indique que depuis 1960, 95 % des submersions ont été générées par la combinaison d'une marée à fort coefficient, d'une surcote (générée par une faible pression atmosphérique et l'action de vents d'afflux) et d'une forte agitation marine. En Bretagne, le passage de fronts froids actifs n'intervient que dans 30 % des cas de submersion mais peut jouer un rôle sur certains sites. L'étude du phénomène de runup à partir de mesures in situ sur deux plages du Finistère apporte un certain nombre de réponses aux questions relatives à ce phénomène jusqu'alors peu étudié. En milieu macrotidal et mégatidal, l'emploi de la pente de la zone intertidale avec les formules issues de la littérature sous-estime vraisemblablement les valeurs de runup. L'utilisation de la pente de la portion mobile prévaut. Dans un troisième temps, la question du risque de submersion marine a été abordé à travers une démarche de recherche appliquée. Une méthode de prévision multi-scalaire des situations à risque en Bretagne et une méthode de cartographie du risque de submersion sont élaborées.

Geometric errors may compromise the quality of radiation therapy treatments. Optimization methods that account for errors can reduce their effects. The first paper of this thesis introduces minimax optimization to account for systematic range and setup errors in intensity-modulated proton therapy. The minimax method optimizes the worst case outcome of the errors within a given set. It is applied to three patient cases and shown to yield improved target coverage robustness and healthy structure sparing compared to conventional methods using margins, uniform beam doses, and density override. Information about the uncertainties enables the optimization to counterbalance the effects of errors. In the second paper, random setup errors of uncertain distribution---in addition to the systematic range and setup errors---are considered in a framework that enables scaling between expected value and minimax optimization. Experiments on a phantom show that the best and mean case tradeoffs between target coverage and critical structure sparing are similar between the methods of the framework, but that the worst case tradeoff improves with conservativeness. Minimax optimization only considers the worst case errors. When the planning criteria cannot be fulfilled for all errors, this may have an adverse effect on the plan quality. The third paper introduces a method for such cases that modifies the set of considered errors to maximize the probability of satisfying the planning criteria. For two cases treated with intensity-modulated photon and proton therapy, the method increased the number of satisfied criteria substantially. Grasping for a little less sometimes yields better plans. In the fourth paper, the theory for multicriteria optimization is extended to incorporate minimax optimization. Minimax optimization is shown to better exploit spatial information than objective-wise worst case optimization, which has previously been used for robust multicriteria optimization. The fifth and sixth papers introduce methods for improving treatment plans: one for deliverable Pareto surface navigation, which improves upon the Pareto set representations of previous methods; and one that minimizes healthy structure doses while constraining the doses of all structures not to deteriorate compared to a reference plan, thereby improving upon plans that have been reached with too weak planning goals. / <p>QC 20130516</p>

Current production methods for creating a motion system for a deformable digital character model involve providing an underlying joint structure based o of a T-Pose, A-Pose or another arbitrary bind pose of the character. A bind pose is required to establish the skeleton-to-geometry spatial relationship that will be used as a mathematical reference to determine geometry deformations in animated poses. Using a set of human motion capture performances as input animation, the impact of the standard T-Pose and A-Pose on the stretching and compression of human character model geometry is compared relative to novel mean poses derived from each performance. Results demonstrate that using an averaged joint position of each specific performance as the bind pose for the performance reduces the overall deformation of the model. Appropriate applications of the mean pose as a bind pose could impact the resources required to repair deformation artifacts in animated deformable digital characters.

Infolge des Herstellungsprozesses textiler Bewehrungen ergeben sich unterschiedliche Materialeigenschaften in den beiden Hauptrichtungen (Schuss und Kette). Diese Unterschiede entstehen durch verschiedene Einflussfaktoren, z. B. aus dem Verbundverhalten oder der Querschnittsform der Rovings. Um das Tragverhalten des anisotropen Verbundwerkstoffes Textilbeton experimentell untersuchen zu können, müssen mögliche Einflüsse aus dem Versuchsaubau möglichst gering gehalten werden, bzw. – falls unvermeidbar – in ihrer Wirkung qualitativ und quantitativ bestimmt und bei der Auswertung der Versuchsergebnisse berücksichtigt werden. Auf der Grundlage der durchgeführten umfangreichen experimentellen Untersuchungen wird eine qualitative Bewertung des Versuchsstandes sowie der verwendeten berührungslosen Messtechnik, der Nahbereichsphotogrammetrie, vorgenommen.

One of the objectives of disaggregation in hierarchical production planning is to minimize the setup costs incurred when changing production from one family to another. In this research, the setup costs are reduced by determining a production schedule that minimizes the number of setups during the planning horizon. Previous solutions to the disaggregation problem have considered discrete-time, and more recently continuous-time formulations. This research extends the continuous time disaggregation approach by incorporating production schedules allowing backorder. A mathematical formulation and a solution algorithm are presented and the computational complexity and convergence properties of the algorithm are discussed. Experimental results, using both deterministic and stochastic demand patterns, which demonstrate the efficacies of the solution approach are provided.

In cellular manufacturing systems, minimization of the completion time has a great impact on the production time, material flow, and productivity. An effective scheduling is crucial to attaining the advantages of cellular manufacturing systems. This dissertation attempts to solve the Flowshop Manufacturing Cell (cellular flowshop) Scheduling Problem with Sequence Dependent Setup Times (FMCSP with SDSTs) considering two performance measures: the total flow time as a mono objective, and the makespan and total flow time combined as a bi-criteria scheduling problem. The proposed problem is known to be the NP-hard problem because of its complexity. Several metaheuristic algorithms based on Genetic Algorithm (GA), Simulated Annealing (SA), and Particle Swarm Optimization (PSO) are developed for scheduling part families as well as jobs within each part family for FMCSP with SDSTs to minimize the total flow time. A local search method based on SA combined with PSO (named as PSO-SA) is proposed to enhance the intensification and improve the quality of the solution obtained by pure PSO. The effectiveness and efficiency of the proposed metaheuristics are evaluated based on the Relative Percentage Deviation (RPD) from its lower bound, and the robustness. Results indicate PSO-SA is performed similar to best available algorithms for small and medium size test problems. Yet, there is a very small deviation from best results for large problems. A Multi-objective Particle Swarm Optimization (MPSO) and a Multi-objective Simulated Annealing (MOSA) Algorithm are further proposed to solve the bi-criteria optimization problem to minimize the total flow time and makespan simultaneously. An improved PSO is combined with Threshold Acceptance (TA) algorithm to improve effectiveness of the proposed MPSO (named as IMPSO-TA) for the convergence of the obtained Pareto Front. The proposed algorithms are evaluated using several Quality Indicators (QI) measures for multiobjective optimization problems. The proposed algorithms can generate approximated Pareto Fronts in a reasonable CPU time. The proposed IMPSO-SA outperforms MOSA algorithm in terms of CPU time and minimizing the objective functions. / October 2015

In this thesis, an aeroservoelastic test appratus is designed to investigate the flutter phenomena in a low speed wind tunnel environment. Flutter is an aeroelastic instability that may occur at control surfaces of aircrafts and missiles. Aerodynamic, elastic, and inertial forces are involved in flutter. A mathematical model using aeroelastic equations of motion is derived to investigate flutter and is used as a basis to design the test setup. Simulations using this mathematical model are performed and critical flutter velocities and frequencies are found. Stiffness characteristics of the test setup are determined using the results of these simulations. The test setup is a two degrees of freedom system, with motions in pitch and plunge, and is controlled by a servomotor in the pitch degree of freedom. A NACA 0012 airfoil is used as a control surface in the test setup. Using this setup, the flutter phenomena is generated in Ankara Wind Tunnel (AWT) and experiments are conducted to validate the results of the theoretical aeroelastic mathematical model calculations.

Le Cancer, l’une des pathologies les plus fréquentes au sein de la population, possède encore actuellement un taux de morbi-mortalité important tous sexes confondus, et ce malgré les importants progrès diagnostiques et thérapeutiques réalisés. D’un point de vue diagnostique, dans une approche dite de « Biologie de systèmes », en complément de l’étude anatomo- pathologique qui reste la référence, de nouvelles techniques ont été développées pour la caractérisation de profils métaboliques (Métabolomique) d’échantillons tissulaires pathologiques ou non, parmi lesquelles la Spectroscopie RMN HRMAS. Après un bref rappel théorique et avoir dressé le bilan des applications de cette technique en Cancérologie, nous avons exposé les différentes étapes du protocole à mettre en place afin d’envisager son implémentation dans un cadre hospitalier. L’ensemble des résultats présentés permettent d’envisager l’utilisation de cette technique en pratique clinique courante. Il faut néanmoins valider la robustesse des modèles statistiques élaborés et confirmer ces résultats sur de plus grandes cohortes d’échantillons. Des développements technologiques, analytiques et statistiques sont également nécessaires. / Cancer, one of the most frequent pathologies among the population, has still an important morbidity-mortality rate all sex confounded, despite the important diagnostical and therapeutical progresses achieved. From a diagnostical point of view, in a so called “Systems Biology approach”, as a complement of the gold standard histopathological study, some new techniques have been developed for the characterization of metabolic profiles (Metabolomics) of tissular samples pathological or not, among which HRMAS NMR Spectroscopy. After some brief theoretical considerations and after reporting the applications of this technique in Cancerology, we exposed the different steps of the protocol to design in order to consider its implementation in a hospital set up. All the results presented allow considering the use of this technique in a clinical routine. Nevertheless, it is necessary to validate the robustness of the statistical models built and to confirm these results on much larger cohorts of samples. Some technical, analytical and statistical developments are also needed.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22734号 / 医博第4652号 / 新制||医||1046(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 妹尾 浩, 教授 増永 慎一郎, 教授 川口 義弥 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM