<p>An on-line identifier using Functional Link Network (FLN) and Pole-shift (PS) controller for power system stabilizer (PSS) application are presented in this thesis. To have the satisfactory performance of the PSS controller, over a wide range of operating conditions, it is desirable to adapt PSS parameters in real time. Artificial Neural Networks (ANNs) transform the inputs in a low-dimensional space to high-dimensional nonlinear hidden unit space and they have the ability to model the nonlinear characteristics of the power system. The ability of ANNs to learn makes them more suitable for use in adaptive control techniques.</p> <p>On-line identification obtains a mathematical model at each sampling period to track the dynamic behavior of the plant. The ANN identifier consisting of a Functional link Network (FLN) is used for identifying the model parameters. A FLN model eliminates the need of hidden layer while retaining the nonlinear mapping capability of the neural network by using enhanced inputs. This network may be conveniently used for function approximation with faster convergence rate and lesser computational load.</p> <p>The most commonly used Pole Assignment (PA) algorithm for adaptive control purposes assign the pole locations to fixed locations within the unit circle in the z-plane. It may not be optimum for different operating conditions. In this thesis, PS type of adaptive control algorithm is used. This algorithm, instead of assigning the closed-loop poles to fixed locations within the unit circle in the z-plane, this algorithm assumes that the pole characteristic polynomial of the closed-loop system has the same form as the pole characteristic of the open-loop system and shifts the open-loop poles radially towards the centre of the unit circle in the z-plane by a shifting factor &alpha; according to some rules. In this control algorithm, no coefficients need to be tuned manually, so manual parameter tuning (which is a drawback in conventional power system stabilizer) is minimized. The PS control algorithm uses the on-line updated ARMA parameters to calculate the new closed-loop poles of the system that are always inside the unit circle in the z-plane.</p> <p>Simulation studies on a single-machine infinite bus and on a multi-machine power system for various operating condition changes, verify the effectiveness of the combined model of FLN identifier and PS control in damping the local and multi-mode oscillations occurring in the system. Simulation studies prove that the APSSs have significant benefits over conventional PSSs: performance improvement and no requirement for parameter tuning.</p>

Le procédé de dépôt electroless de Cu permet la métallisation de substrats non-conducteurs en utilisant un électrolyte composé d’un agent réducteur et d’un sel de cuivre métallique complexé à pH basique. La réduction spontanée des ions cuivre dans l’électrolyte rend l’électrolyte métastable. Des stabilisants (SB) sont ajoutés pour ralentir la cinétique au sein de l’électrolyte et contrôler la vitesse de dépôt sur le substrat.Ce travail de thèse se concentre sur l’étude de la N,N’-diéthylthiourée (DETU), utilisée comme SB dans les électrolytes electroless de cuivre dans une gamme de concentration allant du µM au nM. Une faible variation de la concentration montre des effets prononcés sur la stabilité de l’électrolyte ainsi que sur la cinétique de dépôt et les propriétés du dépôt lui-même. C’est pour cela que la quantification des SB dans ces électrolytes est d’une importance majeure pour assurer la durabilité du procédé electroless. Le défi principal de ce travail est de développer une méthode de quantification de stabilisants (de 1 à 100 nM) dans les électrolytes electroless de cuivre.L’influence du DETU sur les propriétés du dépôt est étudiée pour différentes durées de dépôt. Le dépôt de cuivre est caractérisé en utilisant différentes techniques telles que les techniques DRX, MEB, AFM et XPS. La structure cristalline et la microstructure des couches de cuivre varient peu avec la concentration de DETU. Par contre, une augmentation de la teneur en nickel augmente la vitesse de dépôt et la taille des grains, rendant les couches déposées plus poreuses.La voltammétrie linéaire à balayage (LSV) sur une électrode d’or est utilisée pour étudier les réactions d’oxydation se déroulant à l’électrode et l’influence du SB. Toutes les signatures voltammétriques sont identifiées. Le profil LSV est sensible à la concentration de SB et la densité de courant globale diminue lorsque la concentration de SB augmente. Ceci est dû à l’adsorption du SB sur l’électrode, qui diminue la densité de sites actifs libres et par conséquent limite la vitesse d’oxydation. L’adsorption de SB sur l’électrode est modélisée en utilisant l’isotherme de Langmuir. La cinétique d’adsorption est étudiée pour des vitesses de balayage variables. Le taux de couverture total de l’électrode est discuté en fonction de la concentration, en faisant l’hypothèse que l’équilibre est atteint aux faibles vitesses de balayage de LSV. Une méthode de suivi des SBs dans les électrolytes de cuivre electroless est proposée. La limite de détection de concentration de DETU est 2 nM. Différents SB ainsi que des mélanges de SB peuvent également être analysés par cette méthode. / The Cu electroless process allows the plating of non-conductive substrates using an electrolyte composed of a reducing agent and a complexed copper metal salt at alkaline pH. Spontaneous reduction of copper ions to metallic copper in the electrolyte makes the process metastable. So called stabilizers (SB) are added to slow down the kinetics in the electrolyte and to control the plating rate.This work focuses on the study of N,N’-diethylthiourea (DETU), which is used as SB in electroless copper electrolytes in concentration ranging from µM to nM. A slight variation of concentration has a strong effect on the electrolyte stability as well as the deposition kinetics and deposit properties. Therefore, quantification of the SBs in the electrolyte is of primary importance for the sustainability of the electroless process. The main challenge of this work is to develop a quantification method of stabilizers (from 1 to 100 nM) in electroless copper electrolytes.The influence of DETU on the deposit properties is studied for various deposition times. The Cu-deposit is characterized using different techniques such as XRD, AFM, HRSEM and XPS. On one hand, the crystalline structure and the microstructure do not vary with the DETU concentration. On the other hand, higher nickel content is found to increase the deposition rate and the grain size, making the deposited layer more porous.Linear sweep voltammetry (LSV) on a gold rotating disk electrode is used to study the oxidation reactions occurring in the electrolyte and the influence of SB. Each voltammetric signature is assigned. The LSV profile is sensitive to SB concentration and the overall current density decrease for increasing SB concentrations. This is assigned to SB adsorption on the electrode, which decreases the density of active free sites and therefore limits the oxidation rate. Adsorption of SB on the electrode is described using the Langmuir isotherm model. Kinetics of adsorption is studied by varying the scan rate. Final electrode coverage is discussed as a function of concentration assuming equilibrium is reached at low LSV scan rates. An analytical method for monitoring SB in electroless copper electrolytes is proposed. The limit of detection for DETU is 2 nM. Various SB and SB mixtures can be monitored as well.

In this master thesis the gyroscopic stabilization of a two-wheeled amphibious concept vehicle is investigated. The key idea is to neutralize external torques applied on the vehicle by the counter torque produced from the two gyroscopes attached on the vehicle. Here the gyroscopes are used as actuators, not as sensors. When a torque is applied in order to rotate a gyroscope whose flywheel is spinning, then the gyroscope precesses and it generates a moment, orthogonal to both the torque and the spinning axis. This phenomenon is known as gyroscopic precession. As the vehicle leans from its upright position we expect to generate sufficient gyroscopic reaction moment to bring the vehicle back and get it stabilized.   We first derive the equations of motion based on Lagrangian mechanics. It is worth mentioning that we only consider the control dynamics of a static vehicle. This is the so called regulator problem where we try to counteract the effects of disturbances. The trajectory tracking (servo problem) and the water-travelling can be considered as an extension of the current project. We linearize the dynamics around an equilibrium and we study the stability of the linearized model. We then design an LQG controller, a Glover-McFarlane controller and a cascade PID controller. Regarding the implementation part, we only focus on the cascade PID controller. The results from both simulations and experiments with a small-scale prototype are presented and discussed. / <p>MARINTEKNIKDAGAR PÅ KTH 2015</p>

Chapter 1 provides some background information on the disease area of cancer and current modes of treatment. Chemotherapy treatment is discussed with a focus on the major cellular targets for these drugs: DNA and microtubules. For each target, classes of active compounds are described along with their mode of action. The microtubule stabilizing agent laulimalide is introduced and a case is made for analogue synthesis. Chapter 2 describes our first generation efforts toward synthesis of des-methyl laulimalide. The target compound is divided into a northern and southern fragment with the synthesis of each fragment described. The preparation of landmark intermediates along the synthetic route is also described. Chapter 3 presents our ongoing efforts toward a second generation synthesis of des-methyl laulimalide. Our progress toward a des-methyl,des-pyran analogue is covered as well. Chapter 4 reviews progress in the area of laulimalide analogue development. Biological assay results and the first insights into structure-activity-relationships are described.

It was accidentally discovered in the 1940s that the addition of lead to double-base propellants, resulted in beneficial burn rate phenomena. However, due to its toxicity the Department of Defense has been trying to find a replacement for lead over the last decade. Research efforts with this goal in mind have generally used the same methodology of either adding different metals, using different grain sizes, or using different concentrations to obtain the same burn rate effects as lead. Although some metal oxides demonstrated significant promise, they also depleted the double-base propellant stabilizer faster than acceptable, decreasing shelf life. The research explored herein does not take the same approach, but rather attempts to replace lead and solve the stability problem at the molecular level using a novel design. The new method was to synthesize a stabilizer ligand complex with a less toxic metal to create a complex that both stabilized the propellant and provides a burn rate modifying agent. First, the synthesises of two leaded complexes, tetrakis (µ3-(4-methyl-3-nitrophenyl imido lead (II))) and bis(dinitrophenyl imido lead(II)) are reported as both a proof of concept and to determine a feasible synthetic pathway. After various unsuccessful attempts using common stabilizer molecules as ligands, n-phenylurea was identified as a suitable analogous stabilizer molecule and was bonded to a cobalt center to create hexa-1-phenylurea cobalt(II) nitrate. Additionally and serendipitously, unreported complexes of metal ions with dicyanamide were discovered, which generated a discussion between ligand strength and metal center. Each of the complexes are characterized in depth and many physical properties determined. / Chemistry

Shipboard MVDC power systems need to support pulsed loads, which have destabilizing ef-fects on the MVDC power transmission bus voltage. Despite the reference shipboard MVDC architecture having energy storage to buffer the large power swings of pulsed loads, a large constant power still needs to be delivered to maintain the energy storage state of charge. This recharging constant power itself introduces small signal instability to the MVDC bus voltage. This thesis investigates the advantages of adding a dynamically tuneable virtual capacitor and resistor in parallel to the pulsed load for maintaining small signal stability. The stabi-lizer is implemented in a negative load configuration in the existing reference architecture hardware, where the stabilizer negatively impacts the power quality of the downstream load. To address this, a dual use is added to existing hardware by having the energy storage also cancel out the newly introduced noise. A controller was designed to control a MVDC power converter module for providing these stability services. In addition, the controller manages its internal energy storage and stabilizes its internal DC bus that powers its downstream pulsed load. / Future ships will have a special shipboard power grid and power converters to power future electronics. Most of these power converters will have an internal battery device that provides power when the generators do not provide enough power. Generators are very slow to change their power output. Some shipboard electronics may consume very large amounts of power at very quickly changing rates, causing instability to the power system. The batteries can accomodate the instability caused by these electronics. However, the batteries need to be quickly recharged, which is also unstable to the special power grid. This thesis modifies the recharging behavior so that it does not cause this instability. Also, it is preferable that the batteries will only draw power from the power grid in one direction and send power to the power consuming electronics. This setup is called negative load. This setup is preferable, because sending power back to the power grid will require extra hardware. Ships can only carry so much equipment due to constraints in weight or room, so additonal hardware is undesireable. There already exists similar research to provide this stabilizing service, but they are not designed for a shipboard power grid supporting these quick high power electronics. This thesis also makes a controls system that manages the battery and other requirements of the power system.

Tato diplomová práce se zabývá návrhem stavitelného stabilizátoru za účelem vyvažování letounu a zlepšení jeho letových výkonů. Cílem práce bylo navrhnout konstrukční řešení ovládání a zavěšení horizontálního stabilizátoru. Součástí je pevnostní výpočet kritických konstrukčních prvků a návrh letových zkoušek. V závěru jsou zhodnoceny výhody a nevýhody nového řešení a posouzení možnosti sériové výroby. Klíčová slova Ultralight, JA – 400, stabilizátor, stavitelný stabilizátor, vodorovné ocasní plochy, vyvážení. Abstract This thesis describes the design of adjustable stabilizer for the purpose of balancing the aircraft and improve its flight performance. The aim was to propose a design solution for control and hinge system of horizontal stabilizer. It includes the strength calculation of critical structural components and the design of flight tests. The conclusion evaluates the pros and cons of the new solutions and possibilities of mass production.

[pt] Métodos computacionais se tornam essenciais diante de problemas complexos onde a intuição humana e métodos tradicionais falham. Trabalhos recentes apresentam redes neurais artificiais capazes de realizar eficientemente tarefas intratáveis por algoritmos convencionais com o emprego de aprendizado de máquina, tornando-se assim um dos métodos mais populares. Concomitantemente, algoritmos genéticos, inspirados pelos processos biológicos de seleção natural e mutação, têm sido utilizados como método metaheurístico para encontrar soluções de problemas de otimização. Levantamos então a questão se algoritmos genéticos possuem potencial para resolver problemas no contexto da computação quântica, onde a intuição humana decresce à medida que os sistemas físicos crescem. Especificamente, nos concentramos na evolução de códigos de correção de erros quânticos dentro do formalismo de códigos stabilizer. Ao especificar uma função de fitness apropriada, mostramos que somos capazes de evoluir códigos celebrados, como o código do Shor e o perfeito de 9 e 5 qubits respectivamente, além de novos exemplos não antecipados. Adicionalmente, comparamos com o método força bruta de busca aleatória e verificamos uma crescente superioridade do algoritmo genético conforme aumenta-se o número total de qubits. Diante dos resultados, imaginamos que algoritmos genéticos possam se tornar ferramentas valiosas para desempenhar aplicações complexas em sistemas quânticos e produzir circuitos sob medida que satisfaçam restrições impostas por hardware. / [en] Computational methods become essential in the face of complex problems where human intuition and traditional methods fail. Recent works present artificial neural networks capable of efficiently performing tasks intractable by conventional algorithms using machine learning, rendering it one of the most popular methods. Concomitantly, genetic algorithms, inspired by the biological processes of natural selection and mutation, have been used as a metaheuristic method to find solutions to optimization problems. We then raise the question of whether genetic algorithms have the potential to solve problems in the context of quantum computing, where human intuition decreases as physical systems grow. Specifically, we focus on the evolution of quantum error-correcting codes within the stabilizer code formalism. By specifying an appropriate fitness function, we show that we can evolve celebrated codes, such as the Perfect and Shor s code with respectively 5 and 9 qubits, in addition to new unanticipated examples. Additionally, we compared it with a brute force random search and verified an increasing superiority of the genetic algorithm as the total number of qubits increases. Given the results, we foresee that genetic algorithms can become valuable tools to perform complex applications in quantum systems and produce tailored circuits that satisfy restrictions imposed by hardware.

Each elektronics device needs power supply voltage with special parameters. Voltage regulators warrant this special parameters. This thesis deal with principles of switching voltage regulator, especially step-down convertor, its features and ways to microprocessor based control of the convertor.

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