Afin d’introduire de nouvelles fonctions dans les commandes de vol d’hélicoptère, il est nécessaire d’augmenter les bandes passantes de leurs actionneurs. La modélisation réaliste de l’ensemble du système d’actionnement, rendant compte de ses limitations de puissance et de sa consommation énergétique, ainsi que l’amélioration des technologies existantes des dispositifs d’étanchéité et de guidage sont les deux enjeux principaux permettant d’atteindre la durée de vie souhaitée à hautes fréquences. Pour supporter ce nouveau développement, ce travail s’organise en trois parties. Une première partie présente l’état de l’art des commandes de vol de l’hélicoptère. Une architecture générique d’actionneur est proposée ainsi que la terminologie associée. Une deuxième partie porte sur l’élaboration d’un modèle de connaissance détaillé à l’aide du formalisme Bond-graph pour le système d’actionnement. Un effort particulier est porté sur la standardisation des composants et de leurs interfaces dans une démarche orientée objet. La dernière partie traite concerne les dispositifs d’étanchéité et de guidage au niveau des vérins de commande de vol. Compte tenu de l’objectif d’utiliser des paliers fluides, les différentes manières de générer une force normale au sein d’un film fluide sont analysées. Puis, une étude plus approfondie des butées hydrostatiques et des paliers hybrides coniques est ensuite conduite en tenant compte des contraintes propres à l’aéronautique. L’ensemble des connaissances acquises sont appliquées à un cas concret de développement assisté par les modèles d’actionneur hautes fréquences pour le contrôle actif de rotor. / In order to introduce new functions in helicopter flight controls, it is necessary to increase the bandwidths of their actuators. A realistic modelling of the entire actuating system, taking into account its power limitations and its energy consumption, as well as the improvement of the existing sealing and guiding device technologies are the two main challenges to reach the desired high frequency without reducing dramatically the actuator lifespan. To support this new development, this work is organized in three parts. A first part presents the state of the art of the helicopter flight controls. A generic actuator architecture is proposed as well as the associated terminology. A second part deals with the development of a detailed knowledge-model using the Bond-graph formalism for the actuating system. A particular effort is made to standardize the components and their interfaces in an object-oriented approach. The last part deals with the sealing and guiding devices of flight control cylinders. Given the objective of using fluid bearings, the various ways of generating a normal force within a fluid film are analyzed. Then, a more detailed study of the hydrostatic thrust bearings and the conical hybrid bearings is then carried out taking into account the constraints specific to aeronautics. All the knowledge acquired is applied to a concrete case of development, aided by the models, of high frequency actuators for the active control of a rotor.

Standard crystalline silicon photovoltaic (PV) modules are designed to continuously convert solar energy into electricity for 25 years. However, the continual generation of electricity by the PV modules throughout their designed service life has been a concern. The key challenge has been the untimely fatigue failure of solder interconnections of solar cells in the modules due to accelerated thermo-mechanical degradation. The goal of this research is to provide adequate information for proper design of solar cell solder joint against fatigue failure through the study of cyclic thermo-mechanical stresses and strains in the joint. This is carried-out through finite element analysis (FEA) using ANSYS software to develop the solar cell assembly geometric models followed by simulations. Appropriate material constitutive model for solder alloy is employed to predict number of cycles to failure of solder joint, hence predicting its fatigue life. The results obtained from this study indicate that intermetallic compound thickness (TIMC); solder joint thickness (TSJ) and width (WSJ) have significant impacts on fatigue life of solder joint. The impacts of TIMC and TSJ are such that as the thicknesses increases solder joint fatigue life decreases. Conversely, as solder joint width (WSJ) increases, fatigue life increases. Furthermore, optimization of the joint is carried-out towards thermo-mechanical reliability improvement. Analysis of results shows the design with optimal parameter setting to be: TIMC -2.5μm, TSJ -20μm and WSJ -1000μm. In addition, the optimized model has 16,264 cycles to failure which is 18.82% more than the expected 13,688 cycles to failure of a PV module designed to last for 25 years.

The Hegselmann-Krause system (HK system for short) is one of the most popular models for the dynamics of opinion formation in multi agent systems. Agents are modeled as points in opinion space, and at every time step, each agent moves to the mass center of all the agents within unit distance. The rate of convergence of HK systems has been the subject of several recent works and the current best bounds are O(n3) in one dimension and O(n4) in higher dimension where n being the number of agents. In this work, we investigate the convergence behavior of a few natural variations of the HK system and their e act on the dynamics. In the rest variation, we only allow pairs of agents who are friends in an underlying social network to communicate with each other and we can construct conjurations. In the second variation, only one of the agents updates its position at each time step and selection of such an agent may be at random or based on some preened order; as before, these updates of agents also take social information into consideration. In the third variant, agents may not move exactly to the mass center but somewhere close to it. In the fourth variant, we allow all agents to interact with one another, but instead of assigning equal weights to all neighbors as in the HK model, we assign Gaussian weights which are inversely proportional to the distance between agents. In the fifth variant, we consider the Synchronized Bounded In hence model where the agents have in hence bounds instead of con dance bounds, which changes the way agents interact with each other. In our nil variant, we consider the dynamics of HK systems with strategic agents where we have an additional set of agents called as strategic agents whose opinions are chosen freely at each time step. One of the goals using these strategic agents is to lower the convergence time. The dynamics of all the variants are qualitatively very different from that of the classical HK system. Nevertheless, we prove convergence or show some other interesting results for all of these models. To be more specific, for the rest and third variant we show that these systems make only polynomial number of non-trivial steps, regardless of the social network in the rest vary-ant and noise patterns in the third variant. For the second variant, however, we again show polynomial number of non-trivial steps but in expectation regardless of the social network and interestingly different dynamics. For the fourth variant, we prove an upper bound for the convergence time of Gaussian weighted HK model. For the fifth variant, we consider a special case of this SBI model and prove convergence for this case. For the final variant, we improve the existing results for the optimal convergence time for dumb-bell and equidistant configurations.

Understanding the processes that govern pre-systemic drug absorption and elimination is of high importance in pharmaceutical research and development, and clinical pharmacotherapy, as the oral route remains the most frequently used route of drug administration. The emergence of systems pharmacology has enabled the utilisation of in silico physiologically-based pharmacokinetic (PBPK) modelling and simulation (M&S) coupled to in vitro-in vivo extrapolation in order to perform extrapolation and exploratory M&S in special populations and scenarios were concerns regarding alterations in oral drug exposure may arise, such as following gastrointestinal (GI) surgery or metabolic drug-drug interactions (DDIs).Due to the multi-factorial physiological implications of bariatric surgery, resulting in the partial resection of the GI tract, the inability to rationalise and predict trends in oral drug bioavailability (Foral) following surgery present considerable pharmacotherapeutical challenges. PBPK M&S is a highly implemented approach for the prediction of DDIs. Reoccurring issues have emerged with regards to predictions of the magnitude of mechanism-based inhibition (MBI) where overestimations of DDIs have repeatedly been reported for drugs exhibiting high intestinal extraction. The aim of this thesis was to explore the interplay between oral drug absorption and metabolism occurring in the GI tract through the exploration of the impact of bariatric surgery on oral drug exposure and by theoretically examining the nesting and hierarchy of enterocyte and enzyme turnover and its impact on MBIs in the small intestine. This would be carried out by utilising a systems pharmacology PBPK M&S approach under a general model development framework of identification and characterisation of critical intrinsic factors and parameters, model implementation and validation. Developed post bariatric surgery PBPK models allow a framework to theoretically explore physiological mechanisms associated with altered oral drug exposure pre to post surgery, which could be assigned to the interplay between dissolution, absorption and gut-wall metabolism, where dissolution and formulation properties emerged as the perhaps most important parameters in predicting the drug disposition following surgery. Model validation identified missing critical factors that are essential for additional model refinement. Developed post bariatric surgery PBPK models have the potential of aiding clinical pharmacotherapy and decision-making following surgery. A mechanistic PBPK model was developed to describe the hierarchical dependency of enzyme and enterocyte turnover in the small intestine. Predicted enzyme recovery using the nested enzyme-within-enterocyte turnover model may potentially account for reported overpredictions of mechanism-based inhibition. Developed models in this thesis showcase the advantage of PBPK M&S in the extrapolation of oral drug exposure to special population and the potential of a PBPK approach in understanding underlying the underlying mechanism governing Foral and additionally highlight the need for generation of interdisciplinary data to support model development.

Graphene-based conductor materials (GCMs) consist of stacked and decoupled layers of graphene flakes and could potentially transfer graphene’s outstanding material properties like its exceptional electrical conductivity to the macro scale, where alternatives to the heavy and expensive metallic conductors are desperately needed. To reach super-metallic conductivity however, a systematic electrical conductivity optimization regarding the structural and physical input parameters is required. Here, a new trend in the field of process and material optimization are data-based models which utilize data science methods to quickly identify and abstract information and relationships from the available data. In this work such data-based models for the conductivity of a real GCM thin-film sample are build on data generated with an especially improved and extended version of the network simulation approach by Rizzi et al. [1, 2, 3]. Appropriate methods to create data-based models for GCMs are thereby introduced and typical challenges during the modelling process are addressed, so that data-based models for other properties of GCMs can be easily created as soon as sufficient data is accessible. Combined with experimental measurements by Slawig et al. [4] the created data-based models allow for a coherent and comprehensive description of the thin-films’ electrical parameters across several length scales.:List of Figures List of Tables Symbol Directory List of Abbreviations 1 Introduction 2 Simulation approaches for graphene-based conductor materials 2.1 Traditional simulation approaches for GCMs 2.1.1 Analytical model for GCMs 2.1.2 Finite element method simulations for GCMs 2.2 A network simulation approach for GCMs 2.2.1 Geometry generation 2.2.2 Electrical network creation 2.2.3 Contact and probe setting 2.2.4 Conductivity computation 2.2.5 Results obtained with the network simulation approach 2.3 An improved implementation for the network simulation 2.3.1 Rizzi’s implementation of the network simulation approach 2.3.2 An network simulation tool for parameter studies 2.3.3 Extending the network simulation approach for anisotropy investigations and multilayer flakes 3 Data-based material modelling 3.1 Introduction to data-based modelling 3.2 Data-based modelling in material science 3.3 Interpretability of data-based models 3.4 The data-based modelling process 3.4.1 Preliminary considerations 3.4.2 Data acquisition 3.4.3 Preprocessing the data 3.4.4 Partitioning the dataset 3.4.5 Training the model 3.4.6 Model evaluation 3.4.7 Real-world applications 3.5 Regression estimators 3.5.1 Mathematical introduction to regression 3.5.2 Regularization and ridge regression 3.5.3 Support Vector Regression 3.5.4 Introducing non-linearity through kernels 4 Data-based models for a real GCM thin-film 4.1 Experimental measurements 4.2 Simulation procedure 4.3 Data generation 4.4 Creating data-based models 4.4.1 Quadlinear interpolation as benchmark model 4.4.2 KR, KRR and SVR 4.4.3 Enlarging the dataset 4.4.4 KR, KRR and SVR on the enlarged training dataset 4.5 Application to the GCM sample 5 Conclusion and Outlook 5.1 Conclusion 5.2 Outlook Acknowledgements Statement of Authorship

This diploma thesis focuses on an analysis, a model creation and simulations of a car boot door mechanism. The problem was analyzed on the basis of real measurements made on three different vehicles. Based on the measurements, computational models describing the real system at different levels of complexity were created. Matlab/Simulink was used to create and calculate the models. The output of the thesis is the simulator of a car boot door which also includes simplified model of a control unit. The simulator should provide an approximation of current and kinematic quantities of these mechanisms. The model is implemented on dSPACE platform that allows real-time simulations. The simulator can be modified in terms of changing the parameters of the mechanism and modifying some of its results.

Air pollution harms the environment and human welfare. Computer models and their simulation are useful tools for deeper understanding of processes behind as they quite accurately represent the dispersion and transformation of pollutants with advection diffusion equation or by other concepts. Current models give valid results only to constrained cases of initial conditions. The general model combining the several specific models which is able to change according to input parametres and improve with training is proposed. The adaptiveness of the system is provided by decision tree as data structure with information for selection and combination process and genetic algorithm as optimization method for adjusting the tree. The evaluation of implemented system proves that the combination of models gives better results than models themselves. Even with simple specific models, the system has achieved results comparable to state-of-art models of air pollution.

The reduction in energy consumption is nowadays of increasing importance also within the field of waste water treatment. In combination with increasing requirements for the WWTP (waste water treatment plant) outlet quality, the energy optimization becomes very challenging for the plants operators. This thesis presents possible approaches to the energy optimization and summarizes technologies and measures, where some of them are in the research phase while others are already implemented successfully. In particular, the contribution of the activation tanks aeration process to the overall energy consumption of a plant is highlighted. A change in the aeration control is tested using a mathematical model of WWTP in Mikulov, South Moravia in Czech Republic. In the new setting the aeration is regulated based on the concentration of nitrogen compounds in the activation tank. There is also a brief survey of the energy consumption of the plant and an outline of other possible energy conservation measures.

The geographical information system GRASS has become a standard on the field of geographical phenomenon modeling during its 26 years old lifetime. However, its internal structure follows practices from the date of its creation. This thesis aims to design a possible shape of internal parts modernization using a component architecture and object-oriented design patterns with distributed computing and dynamic languages support in mind. The designed system should stay identical from the user's point-of-view. Design results are proven on a prototype library implementation called the GAL Framework.

We introduce and demonstrate a simple and efficient method for simulating mixtures of legacy and autonomous trains. The method generalises an earlier simulation that we developed for legacy-only operations, in which trains run according to fixed-block signalling rules. Autonomous trains, which use moving-block signalling rules, are incorporated into this framework by employing an overlapping set of short virtual fixed-blocks. Safe occupancy is then maintained by using shadowing rules that link the two sets of blocks. The paper gives relevant rail background, details of the proposed simulation rules, and demonstrates exemplar solution trajectories. The simulation technique is validated both in terms of maintaining safe occupancy and providing a close approximation of the true continuous-space dynamics of autonomous leader-follower pairs. At the Dresden meeting, a variety of interesting mixed-fleet capacity results will also be presented.