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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Simulace analogových hudebních efektů pomocí nelineárních filtrů / Simulation of analogue audio effecs using the nonlinear filters

Otoupalík, Petr January 2010 (has links)
This thesis deals with a simulation of analogue audio effects using the nonlinear models that replace the analogue nonlinear devices in discrete domain. The thesis describes Volterra system model and simplified Volterra system model that can be realized in two ways, either Wiener model, or Hammerstein model. The method for the analysis and modeling of audio and acoustic nonlinear systems is presented in this thesis. This method allows through knowledge of the input swept-sine signal and the response of the analogue nonlinear system to the input signal to determine the coefficients of the discrete nonlinear system. This allows simulating the analogue nonlinear system in discrete domain. The method was first tested and then used successfully for simulation of the analogue nonlinear system in discrete domain. Concretely, it was simulated a musical guitar effect of the type of distortion. Last part of this thesis is devoted a description of VST technology and an implementation of VST plug-in module, which realizations Hammerstein model.
62

Testování prostorové akustiky / Testing of room acoustics

Toufarová, Tereza January 2011 (has links)
This paper presents parameters of evaluation of acoustic quality of the space. It is divided into parts presenting physical principle of the origin and movement of the acoustic signal, principles of its processing with current technology and properties of the acoustic field. This is followed by an analysis of the musical part and notes on psychoacoustics. The document contains a description of relevant parameters of acoustic spaces and way in which we can reach desired results, including material analysis. The paper mainly focuses on description of relevant parameters of three acoustic spaces which were measured. The last part of the work is a program for elementary acoustical measurement, which can be provided by means of commonly accessible equipment such as a notebook or a personal computer.
63

Analysis of Unsteady Incompressible Potential Flow Over a Swimming Slender Fish and a Swept Wing Tail

Nathan, Vinay January 2015 (has links) (PDF)
This thesis deals with computing the pressure distribution around a swimming slender fish and the thrust generated by its flapping motion. The body of the fish is modeled as a missile like slender body to which a tail is attached that is modeled as a swept wing. The tail is attached to the tip of the slender body and maintains its slope with it. The motion for the swimming fish is prescribed. The fluid flow is modeled as an unsteady potential flow problem with the flow around the slender body modeled as flow over an array of cylinders of varying radii and the flow over the swept wing modeled using the vortex panel method. The pressure distribution is computed using the unsteady Bernoulli equation. The overall thrust & drag for different parameters are studied and compared
64

Development and characterization of an optical coherence tomography micro-system : Application to dermatology / Développement et caracterisation d'un microsystème de tomographie par cohérence optique plein champ à balayage en longueur d'onde : Application à la dermatologie

Perrin, Stephane 24 June 2016 (has links)
Ce manuscrit de thèse de doctorat présente la conception et la réalisation d’un système d’imageriepour le diagnostic précoce des pathologies de la peau. Un diagnostic précoce permet de réduire lesactes chirurgicaux inutiles. Il est important de mettre en avant que seulement 20% des pathologiesfaisant office d’une opération chirurgicale, sont malignes. De plus, les pronostics de l’année 2015avançaient trois millions de nouveaux cas de cancer de la peau diagnostiqués aux ´ Etats-Unis. Basésur la tomographie par cohérence optique à balayage en longueur d’onde et une configuration pleinchamp et multi-canaux, le système d’imagerie médicale est capable d’imager en volume les couchesinternes de la peau et donc de fournir un diagnostic médical pour le professionnel de santé. Pourune fabrication en série du système portatif, les composants optiques sont micro-fabriqués sur dessubstrats et assemblés verticalement. Ces micro-composants optiques requièrent une caractérisationspécifique. Pour cela, deux systèmes ont ainsi été développés pour estimer leurs performancesoptiques. Ce travail a été réalisé dans le cadre du projet Européen VIAMOS (Vertically IntegratedArray-type Mirau-based OCT System). / The manuscript concerns the optical design and the development of a non-invasive new imagingsystem for the early diagnosis of skin pathologies. Indeed, an early diagnosis can make the differencebetween malignant and benign skin lesion in order to minimize unnecessary surgical procedure.Furthermore, prognosis for the year 2015 was that more than three millions new skin cancer caseswill be diagnosed in the United States. Based on the swept source optical coherence tomographytechnique in full-field and multiple channels configuration, the imaging system is able to perform avolumetric image of the subsurface of the skin, and thus can help in taking a better medical decision.Furthermore, for a batch-fabrication of the hand-held device, micro-optical components were made atwafer-level and vertically assembled using multi-wafer bonding. This miniaturized system requiresspecific characterization. Thus, two systems were also developed for imaging quality evaluation ofmicro-optical elements. This work has been supported by the VIAMOS (Vertically Integrated ArraytypeMirau-based OCT System) European project.
65

Longitudinal handling characteristics of a tailless gull-wing aircraft

Agenbag, Daniel Sarel 18 September 2008 (has links)
A handling quality investigation was performed on the swept gull-wing configuration. The swept gull-wing configuration is tailless and has a wing with a transition in the sweep and dihedral angle. An example of this type of aircraft is the Exulans. This aircraft is currently under development at the University of Pretoria. The handling quality study was focussed on pitch axis dynamics. The Exulans is a research testbed that will be used to investigate the swept gull-wing configuration and its special controls by means of full-scale flight testing. Variable wing sweep, twisting elevons and winglets will be investigated as means of control. These control devices are configured in such a way as to have minimum impact on the performance of the aircraft. The handling qualities of the swept gull-wing configuration have to be acceptable while using these different control strategies. The study was launched to investigate whether a gull-wing configuration aircraft will have satisfactory handling qualities at CG positions associated with the most favourable aerodynamic performance. There is an aerodynamic performance gain in designing an aircraft so that the CG falls on the so-called `E-point'. The E-point is the centre of pressure for an elliptical circulation distribution. An elliptical circulation distribution is associated with the highest Oswald efficiency for an aircraft. Time domain simulation techniques and frequency domain analysis techniques were used to analyse the handling qualities of the gull-wing configuration. The C-star criterion was used to analyse handling qualities with time domain simulation data as input. Comparative time domain simulations were performed between the Exulans and other aircraft to compare handling qualities. Eigenvalue analysis was used together with the thumbprint criterion to investigate inherent gull-wing airframe dynamics. The Shomber-Gertsen and Military Specification 8785 criteria were also used for the same purpose. The Neal-Smith method was used to investigate the effect of control authority on handling qualities and the effect of a pilot. The Monnich and Dalldorff criterion was used to evaluate gust handling qualities. An analysis chart by Fremaux and Vairo was used to evaluate the tumbling susceptibility of the gull-wing configuration. The pitch handling quality investigation shows sufficient promise that the swept gull-wing configuration will have acceptable handling qualities with the CG placed at positions associated with optimised aerodynamic performance. Analysis showed that the swept gull-wing configuration is potentially prone to tumbling. With low static margins, the configuration should exhibit improved handling qualities in gusty conditions when compared to existing tailless aircraft. It is recommended that a lateral handling quality study be performed before full scale flight testing commences on the Exulans. In addition, the possibility of wingtip stall must be investigated for the case of the swept gull-wing configuration. / Dissertation (MEng)--University of Pretoria, 2008. / Mechanical and Aeronautical Engineering / unrestricted
66

Přední náprava vysokovýkonného sportovního vozu / Front Axle of a High-performance Sports Car

Hrudík, Jan January 2011 (has links)
Tato diplomová práce byla psána při studentské zahraniční stáži, pod záštitou Evropské Unie – program „ERASMUS Student Mobility for Placement“. Stáž byla absolvována mezi prosincem 2010 a květnem 2011 ve společnosti a.d.Tramontana, mající sídlo v Palau de Santa Eulália, Španělsko. Pro kompletní návrh podvozku a odpružení jakéhokoli vozidla je nezbytná znalost mnoha technických disciplín. Tato diplomová práce se zabývá dvěma z nich – odpružení a řízení. Nejprve je rozebrána teorie, na kterou se může navázat v praktické části práce. Velká pozornost byla věnována srozumitelnosti textu a názornosti obrázků, bez zbytečných detailů, avšak bez vynechání důležitého. Tuto práci je tedy možné užít jako prvního kroku před návrhem podvozku. V další části je popsáno, jak byla probraná teorie využita při návrhu řízení u skutečného vozu, přičemž největší pozornost je věnována Ackermannově teorii řízení a geometrii zabraňující samořízení při propružení. V závěrečných částech je pozornost věnována ukázce některých z každodenních činností v malosériové výrobě automobilů – jde o zjištění maximálně možného pohybu kola při propružení a proces výroby příčných trojúhelníkových ramen včetně návrhu jejich připevnění k šasi.

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