Sound Source Separation refers to separating sound signals according to their sources from a given observed sound. It is efficient to code and very easy to analyze and manipulate sounds from individual sources separately than in a mixture. This thesis deals with the problem of source separation in monaural recordings of harmonic musical instruments. A good amount of literature is surveyed and presented since sound source separation has been tried by many researchers over many decades through various approaches. A prediction driven approach is first presented which is inspired by old-plus-new heuristic used by humans for Auditory Scene Analysis. In this approach, the signals from different sources are predicted using a general model and then these predictions are reconciled with observed sound to get the separated signal. This approach failed for real world sound recordings in which the spectrum of the source signals change very dynamically. Considering the dynamic nature of the spectrums, an approach which uses covariance matrix of amplitudes of harmonics is proposed. The overlapping and non-overlapping harmonics of the notes are first identified with the knowledge of pitch of the notes. The notes are matched on the basis of their covariance profiles. The second order properties of overlapping harmonics of a note are estimated with the use of co-variance matrix of a matching note. The full harmonic is then reconstructed using these second order characteristics. The technique has performed well over sound samples taken from RWC musical Instrument database.

Internal gravity waves play a fundamental role in the dynamics of stably stratified regions of the atmosphere and ocean. In addition to the radiation of momentum and energy remote from generation sites, internal waves drive vertical transport of heat and mass through the ocean by wave breaking and the mixing subsequently produced. Identifying regions where internal gravity waves contribute to ocean mixing and quantifying this mixing are therefore important for accurate climate and weather predictions. Field studies report significantly enhanced measurements of turbulence near 'rough' ocean topography compared with those recorded in the ocean interior or near more gradually varying topography (e.g. Toole et al. 1997, J. Geophys. Res. 102). Such observations suggest that interaction of waves with rough topography may act to skew wave energy spectra to high wavenumbers and hence promote wave breaking and fluid mixing. This thesis examines the high wavenumber scatter and spatial partitioning of wave energy at 'rough' topography containing features that are of similar scales to those characterising incident waves. The research presented here includes laboratory experiments using synthetic schlieren and PIV to visualise two-dimensional wavefields produced by small amplitude oscillations of cylinders within linear salt-water stratifications. Interactions of wavefields with planar slopes and smoothly varying sinusoidal topography are compared with those with square-wave, sawtooth and pseudo knife-edge profiles, which have discontinuous slopes. Far-field structures of scattered wavefields are compared with linear analytical models. Scatter to high wavenumbers is found to be controlled predominantly by the relative slopes and characterising length scales of the incident wavefield and topography, as well as the shape and aspect ratio of the topographic profile. Wave energy becomes highly focused and the spectra skewed to higher wavenumbers by 'critical' regions, where the topographic slope is comparable with the slope of the incident wave energy vector, and at sharp corners, where topographic slope is not defined. Contrary to linear geometric ray tracing predictions (Longuet-Higgins 1969, J. Fluid Mech. 37), a significant back-scattered field can be achieved in near-critical conditions as well as a forward scattered wavefield in supercritical conditions, where the slope of the boundary is steeper than that of the incident wave. Results suggest that interaction with rough benthic topography could efficiently convert wave energy to higher wavenumbers and promote fluid mixing in such ocean regions.

The aim of the diploma thesis is to design the technical solution of minimization of frictional losses, which occur when using a sine pump at position of the shaft locking and on the impeller wheel. The losses originating from the frictional forces have a negative influence on the lifetime of individual parts and economy of the pump. In the first part the author describes sine pumps from the constructional point of view and the main producers are mentioned. The second part contains suggestions on the parameters of the pump and various possibilities of solutions. The last part covers the experiment and conclusions.

During the creation of any concrete floor the concrete needs to be grinded down from it's very rough newly poured form to a more usable floor surface. Concrete floor grinding is very special in that the work area is often immensely large while the height difference on the surface is incredibly small, in-fact the the largest local difference of the surface from a peek to a valley during the grinding process is submillimeter and goes down to micrometer scale. Today's methods for measuring concrete surfaces are very few and all output one dimensional profiles of the surface in very time consuming processes which makes them unsuitable for real-time analysis of the surfaces during the grinding process. Because of this, the effectiveness of the work is dependent on the experience and intuition of the operator of the grinding machine as they have to make the decision of when to move on to the next step in the grinding process. Therefore it is desirable to create a better method for concrete surface measurement that can measure big areas in a short period of time. In this project a structured light method using sinusoidal phase shifting is implemented and evaluated with an easily movable setup that can measure the height of a concrete surface over an area. The method works by encoding the surface with a phase using a projector and analysing how the phase encoding warps when imaging it from an angle. By triangulation this can be made into a height map of the measured area. The end results show that the method is promising for this application and can detect the submillimeter differences. However, more suitable hardware and a more reliable calibration procedure are required to move this prototype towards a more practical measuring device.

As the understanding of the workings of the biological world expands, biomimetic designs increasingly move into the focus of engineering research studies. For this thesis, two studiesinvolving leading edge vortex generation for lift production as observed in nature were explored intheir respective flow regimes. The first study focused on the steady state analysis of streamwise vortices generated byleading edge tubercles of an adult humpback whale flipper. A realistic scaled model of a humpbackflipper was fabricated based on the 3D reconstruction from a sequence of 18 images taken whilecircumscribing an excised flipper of a beached humpback whale. Two complementary modelswith smooth leading edges were transformed from this original digitized model and fabricatedfor testing to further understand the effect of the leading edge tubercles. Experimentally-obtainedforce and qualitative flow measurements were used to study the influence of the leading edgetubercles. The presence of leading edge tubercles are shown to decrease maximum lift coefficient(Cl ), but increase Cl production in the post-stall region. By evaluating a measure of hydrodynamicefficiency, humpback whale flipper geometry is shown to be more efficient in the pre-stall regionand less efficient in the post-stall region as compared to a comparable model with a smooth leadingedge. With respect to a humpback whale, if the decrease in efficiency during post-stall angles ofattack was only required during short periods of time (turning), then this decrease in efficiencymay not have a significant impact on the lift production and energy needs. For the pursuit ofbiomimetic designs, this decrease in efficiency could have potential significance and should beinvestigated further. Qualitative flow measurements further demonstrate that these force results aredue to a delay of separation resulting from the presence of tubercles.The second study investigated explored the effects of flapping frequency on the passive flowcontrol of a flapping wing with a sinusoidal leading edge profile. At a flapping frequency of f =0.05 Hz, an alternating streamwise vortical formation was observed for the sinusoidal leading edge,while a single pair of vortices were present for the straight leading edge. A sinusoidal leading edgecan be used to minimize spanwise flow by the generation of the observed alternating streamwisevortices. An increase in flapping frequency results in these streamwise vortices becoming stretchedin the path of the wing. The streamwise vortices are shown to minimize spanwise flow even afterbeing stretched. Once instabilities are formed at f ≥ 0:1 Hz due to velocity shearing generatedby the increase in cross-radial velocity, the alternating streamwise vortices begin to break downresulting in a increase of spanwise flow.

This thesis was written at Airbus DS GmbH in Friedrichshafen, Germany, as part of a project which aims to develop a new generation of class-D power amplification circuits for sinusoidal commutating motors controlling the movement of different mechanisms in satellites. Currently used topologies have disadvantages such as high power loss, analog controlling and high degree of signal distortion. This work first simulates available topologies which were previously developed by the company in order to compare them and build a trade-off list so the most suitable circuit is selected. Then, by further simulating and analysis several improvements to the circuit are suggested and a final schematic is developed including an analogue-to-digital converter and a total of three phases to power a motor. After a demonstrator circuit was designed and built, it was tested by using an external real time target machine to generate the corresponding PWM signals in correspondence to a controlling signal generated via Simulink. The final product of this thesis confirmed the simulation results such as an improved signal quality at higher frequencies in comparison to an available measurement from a previous generation circuit. The flexibility of the topology as well as the possibility of implementing a digital control was also confirmed during this phase of the project. Upon further work, the dimensioning of the output low pass filter should be improved and a digital PID controller should be implemented in the controlling FPGA. / <p>This version of the Master Thesis deviates from the formal original submitted for examination in order not to disclose confidential information of Airbus DS GmbH. All positions in the document, where additional information was removed are properly identified. This document can be published according to the general rules of the Julius-Maximilians-Universität Würzburg and the Lulea University of Technology.</p>

Le développement des véhicules hybrides et électriques s’est intensifié ces dernières années, face aux problématiques environnementales et économiques. Afin que les performances de ces derniers soient comparables à celle d’un véhicule à moteur thermique, de nombreuses avancées technologiques sont indispensables. Le déploiement de véhicule entièrement à traction électrique, ne serait être réalisable, sans des infrastructures de recharge adaptées. Cette thèse constitue une contribution à l’étude d’un chargeur de batteries intégré au véhicule électrique, dans le cadre du projet SOFRACI.L'architecture de ce chargeur entièrement réversible sert également pour la traction du véhicule. L’utilisation de tous les éléments y compris le moteur de traction pour les deux fonctions, réduit l’encombrement et le coût de la structure. L’objectif principal consiste à modéliser le système de conversion alternatif-continu du chargeur et à établir les lois de commandes.Lors de la première phase de l’étude, une attention particulière a été portée à l’utilisation des enroulements de la machine en tant qu’inductance de filtrage du convertisseur. Un modèle correspondant à ce fonctionnement a été obtenu et a permis de mettre en évidence un couplage magnétique existant entre les diverses phases.En s’appuyant sur les modèles obtenues, la seconde étape a consisté à définir les stratégies de commande. Deux méthodes ont été employées. La première, par le biais d’une transformation a permis de se ramener dans un repère, où la majorité des termes de couplage ont été éliminés. Pour l’autre méthode, tous les éléments du couplage ont été considérés. Pour chacune de ces stratégies, des correcteurs PI et RST fondés sur le placement de pôles robustes ont été dimensionnés pour garantir la stabilité du système.Une part importante du travail a été consacrée à la réalisation d’un banc d’essai expérimental reconstituant la conversion alternative-continue. Compte tenu des différences de dynamiques des grandeurs asservies, une carte FPGA et un processeur ont été utilisés. L’exploitation de ce moyen d’essai a permis de comparer et de valider les lois de commande développées. / Environmental constraints and reduction of fossil fuels resources have led industrials and laboratories to search for alternative solutions in the transportation domain. For the last few years, several vehicles or planes functions have been gradually electrified, up to their complete electrification. This thesis presents an AC/DC converter integrated in an Electric Vehicle (EV) for the charger application. The conversion is realized by using the electric traction powertrain, in order to reduce the global cost and increase compactness where a specific motor has been design.During the first phase of the study, a model of the motor used as filtering inductances has been obtained and allowed to highlight an existing magnetic coupling between the motor’s phases.The second step was to define control strategies. Two methods were used. The first one, by a transformation allowed eliminating the majority of the coupling term. In the other method, all coupling elements have been considered. For each strategies, IP and RST controllers based on robust pole placement were designed to ensure system stability.An important part of the work was devoted to the realization of an experimental test bench for AC-DC conversion. A FPGA and a processor were used for control implementation. The control laws has been compared and validated thanks to the experimental platform.

O presente trabalho apresenta uma transformação dq não senoidal e sua aplicação em máquinas síncronas com ímã permanente na superfície do rotor (MSIP) e forma de onda de FEM não senoidal. O modelo resultante da aplicação dessa transformação permite o controle direto do torque eletromagnético, permitindo reduzir as ondulações do torque produzido nesse tipo de máquina. A redução dessas ondulações em MSIPs não senoidais possibilita que esse tipo de máquina seja empregado em aplicações onde somente MSIPs senoidais, que possuem custo mais elevado, poderiam ser usadas. Simulações e resultados práticos, obtidos pela implementação do sistema de controle vetorial não senoidal desenvolvido, são apresentados no trabalho. Pelos resultados obtidos, pode-se verificar que o método proposto é eficaz na redução das ondulações do torque eletromagnético em MSIPs não senoidais. / This work presents a non-sinusoidal dq transformation and its application in permanent- magnet synchronous machines (PMSM) with a non-sinusoidal back-EMF waveform. The resulting model of the application of such transformation permits direct control of machine electromagnetic torque, which achieves the reduction of torque ripple. The reduction of torque ripple in non-sinusoidal PMSMs makes possible the use of this kind of PMSM instead of sinusoidal PMSMs, which are more expensive. Simulation and practical results, obtained by the implementation of such non-sinusoidal vectorial control system, are shown in this work. Those results show that the method presented is efficacious in the torque ripple reduction in non-sinusoidal PM synchronous machines.

O objetivo desse trabalho é o estudo e a análise do desempenho de máquinas brushless com ímã permanente no rotor, com fluxo de entreferro não senoidal. São consideradas máquinas brushless com ímã permanente na superfície do rotor. Três modelos matemáticos são considerados: o modelo por fase de estator, o modelo vetorial e o modelo velocidade-tensão de segunda ordem. Máquinas com diferentes tipos de enrolamento de estator são comparadas, incluindo as máquinas síncronas com ímã permanente no rotor (com a densidade dos enrolamentos distribuída de forma senoidal no estator). Os resultados para o torque eletromagnético das máquinas foram obtidos considerando-se dois tipos de acionamentos em malha aberta: um acionamento de seis pulsos e um acionamento senoidal. Por fim, um método de controle é apresentado para máquinas não senoidais. As ondulações no torque e o desempenho das máquinas não senoidais. As ondulações no torque e o desempenho das máquinas não senoidais, utilizando controle vetorial, são comparados aos das máquinas senoidais. / The aim of this work is to analyse the torque performance of brushless machines with non-sinusoidal distributed magnetic fluxes. The machine type considered is a surface mount permanent magnet brushless machine. Three mathematical models for the machine are considered: the per stator phase, the vectorial and the linear second order speed-voltage models. Machines with different stator windings are compared including the permanent magnet synchronous machines with sinusoidal distributed stator windings. The torque outputs of these machines are obtained considering two kinds of open loop driving systems: one with a six-pulse waveform and other with a sinusoidal waveform. Finally, a vectorial control is proposed for the non-sinusoidal machines. The torque ripple as well the overall performance of non-sinusoidal machines with vectorial control is compared to that of sinusoidal machines.

Este projeto de pesquisa propõe desenvolver um novo modelo e uma nova abordagem para a resolução do problema da otimização Volt/VAr em redes de distribuição de energia elétrica. A otimização Volt/VAr consiste em, basicamente, determinar os ajustes das variáveis de controle tais como bancos de capacitores chaveados, transformadores com comutação de tap sob carga e reguladores de tensão, de modo a satisfazer, simultaneamente, as restrições de carga e de operação para um dado objetivo operacional. Esse problema, matematicamente, foi formulado como um problema de programação não linear, multiperíodo, e com variáveis contínuas e discretas. Algoritmos de programação não linear foram utilizados com o intuito de aproveitar as vantagens das matrizes altamente esparsas montadas ao longo do método de solução. Para utilizar tais algoritmos, as variáveis discretas são tratadas como contínuas por meio da utilização de funções senoidais que penalizam a função objetivo do problema original enquanto estas não convergirem para algum dos pontos pré-definidos no seu domínio. O caráter multiperíodo do problema, contudo, refere-se à consideração de uma restrição que relaciona os ajustes das variáveis de controle para sucessivos intervalos de tempo na medida em que limita o número de operações de chaveamento desses dispositivos para um período de 24-horas. O estudo fundamenta-se, metodologicamente, em métodos do tipo Primal-Dual Barreira-Logarítmica. Para demonstrar a eficiência do modelo proposto e a robustez dessa abordagem, a partir de dados teóricos obtidos de levantamentos bibliográficos, testes foram realizados em sistemas-teste de 10, 69 e 135 barras, e em um sistema de 442 barras do noroeste do Reino Unido. As implementações computacionais foram feitas nos softwares MATLAB, AIMMS e GAMS, utilizando o solver IPOPT como método de solução. Os resultados mostram que a abordagem proposta para a resolução do problema de programação não linear é eficaz para tratar adequadamente todas as variáveis presentes em problemas de otimização Volt/VAr. / This work proposes a new model and a new approach for solving the Volt / VAr optimization problem in distribution systems. The Volt/VAr optimization consists, basically, to determine the settings of the control variables of switched capacitor banks, on-load tap changer transformers and voltage regulators, in order to satisfy both the load and operational constraints, to a given operational objective. The problem is formulated as a nonlinear programming problem, multiperiod, and with continuous and discrete variables. Nonlinear programming algorithms were used in order to take advantage of the highly sparse matrices built along the solution method. The discrete variables are treated as continuous along the solution method by means of the use of sinusoidal functions that penalize the original objective function while the control variables do not converge to any of the predefined discrete points in its domain. The multiperiod, or dynamic, characteristic of the problem, however, refers to the use of a constraint that relates the settings of the control variables for successive time intervals that limits the control devices switching operations number for a period of 24-hours. The study is based, methodologically, on Primal-Dual Logarithmic Barrier method. To demonstrate the effectiveness of the proposed model and the robustness of this approach, the data were obtained from theoretical literature surveys, and tests were performed on test-systems of 10, 69 and 135 buses, and in a 442 buses located in the Northwest of the United Kingdom. The computational implementation was accomplished in the softwares MATLAB, AIMMS and GAMS, using the IPOPT solver as solution method. The results have shown the approach for solving nonlinear programming problems is effective to appropriate cope with all the variables presented in Volt/VAr optimization problems.