Les modulateurs electro-optiques (EOM) sont des composants importants dans les systemes de telecommunication. Malheureusement, ils ne sont pas parfaitement stables dans Ie temps et leur fonction de transfert (TF) a tendance a se decaler durant Ie temps d'operation. La derive de la TF d'un EOM peut etre expliquee par des effets differents tels que les changements de la temperature ambiante, de la polarisation ou de l'efficacite de couplage optique. La these presente une methode de me sure de la derive de la TF de I'EOM (a grace d'estimation du comportement non-linearite du modulateur, NLl), et propose deux systemes instrumentaux pour ameliorer son fonctionnement: Ie premier pour contraler la temperature de l'EOM, il est possible de forcement reduire cette derive, Ie deuxieme pour compenser la derive (la stabilisation du point de fonctionnement autour du point quadrature est obtenue jusqu'au 0,22% ou la fluctuation de phase est de 0,44°). Ces techniques ont ete aussi appliquees pour ameliorer Ie comportement d'un oscillateur optoelectronique haute frequence. Nous avons realise les experiences par asservissement de temperature, par compensation de la derive. Pour une stabilite de I'OEO a court terme, la stabilisation de la frequence est amelioree jusqu'a 28% en utilisant un contrale de temperature seule etjusqu'a 71 % avec les deux processus. Pour une stabilite de l'OEO a long terme, en deux cas sans contra Ie, I'OEO fonctionne pendant 3 heures et pendant 1,6 heure (puis I'OEO ne marche plus). En utilisant une compensation de la derive de la TF de I'EOM, l'OEO fonctionne bien meme apres 7 heures et 8 heures. / Electro-optic modulators (EOM) are important components in telecommunication systems. Unfortunately, there are some physical effects like ambient temperature variations, polarization and inherent photorefractive coefficient which are due to the drift of EOM transfer function (TF). The thesis presents a method for measuring the drift of the TF of EOM (based on a nonlinearity behavior of modulator - NLl), and propose two instrumentation systems to improve their operations: one to control the temperature of EOM, it is possible to significantly reduce the drift, the second to compensate the drift (the bias point stabilization around the quadrature point is obtained up to 0.22% or the phase fluctuation is 0.44°). These techniques have been applied to improve the behavior of an optoelectronic oscillator high frequency. Four experiments are carried out by controlling the EOM temperature and by compensating the EOM drift. For a short-term stability of OEO, the stabilization of the frequency is obtained with 28% with using a temperature control, up to 71 % with the two techniques. For a long-term stability of OEO, in cases without any control, the OEO has worked for 3 hours and for 1.6 hours (then, the OEO does not work anymore). By using the drift compensation of the EOM FT, the OEO has correctly worked even more than 7 hours and 8 hours.

Recently, 3D printing has been increasingly used to create physical models of the vocal tract with geometries obtained from magnetic resonance imaging. These printed models allow measuring the vocal tract transfer function, which is not reliably possible in vivo for the vocal tract of living humans. The transfer functions enable the detailed examination of the acoustic effects of specific articulatory strategies in speaking and singing, and the validation of acoustic plane-wave models for realistic vocal tract geometries in articulatory speech synthesis. To measure the acoustic transfer function of 3D-printed models, two techniques have been described: (1) excitation of the models with a broadband sound source at the glottis and measurement of the sound pressure radiated from the lips, and (2) excitation of the models with an external source in front of the lips and measurement of the sound pressure inside the models at the glottal end. The former method is more frequently used and more intuitive due to its similarity to speech production. However, the latter method avoids the intricate problem of constructing a suitable broadband glottal source and is therefore more effective. It has been shown to yield a transfer function similar, but not exactly equal to the volume velocity transfer function between the glottis and the lips, which is usually used to characterize vocal tract acoustics. Here, we revisit this method and show both, theoretically and experimentally, how it can be extended to yield the precise volume velocity transfer function of the vocal tract.

Multimódová vlákna jsou zobrazovacím prostředkem s významným potenciálem v in-vivo mikroendoskopii. V poslední době tato metoda zaznamenala velký rozvoj, a to díky zdokonalování výpočetní a jiné techniky, například prostorové modulace světla. Cílem této práce bylo nalézt specifické limity zobrazování multimódovými vlákny a představit jejich počítačovou simulaci. Byl zkoumán vliv způsobu osvětlení optického systému obsahujícího multimódové vlákno na jeho schopnost fokusace a zobrazování. Analýzou dat získaných ze simulací a experimentu bylo zjištěno, že různá míra omezení Gaussovského svazku a plnění apertury multimódového vlákna má za následek významnou změnu zobrazovacích schopností systému. Při pozorování kvality fokusace bylo zjištěno, že nejlépe se projevují svazky málo omezené aperturou vlákna. Tento fakt byl potvrzen i experimentálním měřením. Zobrazování za použití svazků s podobnými hodnotami omezení (50%) projevovalo i nejlepší schopnost přenosu kontrastu. Avšak při analýze rozlišení dvou bodových objektů se jako nejvhodnější projevily svazky významně přeplňující numerickou aperturu vlákna, 100% a více. Přítomnost tohoto rozdílu poukazuje na skutečnost, že multimódové vlákno není zcela náhodné médium, ale propagace světla skrz multimódové vlákno projevuje znaky závislosti na vnějších zobrazovacích podmínkách, jako je například změna omezení osvětlovacího svazku. V této práci bylo představeno několik způsobů vyhodnocení kvality zobrazování pomocí multimódového vlákna. Každé z těchto kritérií podalo dílčí charakteristiku chování optického systému obsahujícího multimódové optické vlákno. Jednotlivé výsledky se neshodují na jednom konkrétním řešení a nutí osobu využívající zobrazovací systém obsahující multimódové vlákno ke zvážení několika aspektů, a to v jakém prostředí bude daný optický systém využívat a který parametr kvality zobrazení bude považovat za nejdůležitější.

This diploma thesis is devided into theoretic and practice parts. Theoretic part contains basic information about history and development of Artificial Neural Networks (ANN) from last century till present. Prove of the theoretic section is discussed in the practice part, for example learning, training each types of topology of artificial neural networks on some specifics works. Simulation of this networks and then describing results. Aim of thesis is simulation of the active networks element controlling by artificial neural networks. It means learning, training and simulation of designed neural network. This section contains algorithm of ports switching by address with Hopfield's networks, which used solution of typical Trade Salesman Problem (TSP). Next point is to sketch problems with optimalization and their solutions. Hopfield's topology is compared with Recurrent topology of neural networks (Elman's and Layer Recurrent's topology) their main differents, their advantages and disadvantages and supposed their solution of optimalization in controlling of network's switch. From thesis experience is introduced solution with controll function of ANN in active networks elements in the future.

This thesis deals with artificial simulation of acoustic spaces by using reverberators. Output of this document consists of four reverberation algorithms and function that evaluates objective parameters of acoustic space from impulse responses. Reverberators and script were implemented using Matlab. Graphical user interface is used to present all of the algorithms for easier usability. First chapter deals with objective parameters of acoustic spaces and the ways they are computed from impulse response. Second chapter describes various structures which are used to build reverberators. Those structures are used in third chapter in implementations of reverberators. Third chapter also compares all implemented reverberators . In last chapter experiment was made. Impulse responses of three spaces were measured and subsequently aproximated by algorithms implemented in this thesis.

Dissertation thesis is focused on real digital signal processing by quadrature mirror digital filter banks. In the first part a dual channel quadrature mirror digital filter bank is described briefly. Mainly transfer functions for distorted subband signals are described. In the next part generalized sigma-delta modulator and its linear model are described. Subsequently the generalized sigma-delta modulator is used in decomposition part of quadrature mirror digital filter bank. Designed structure is analyzed. Two design method of transfer functions are designed for the structure on the basis of analysis results. The first method is suitable for hand-made design by intuitive distribution of zeros and poles. The second method is more suitable for computer design. It is iterative method based on correlation. Transfer functions for quadrature mirror digital filter bank with sigma-delta modulators design examples are also part of thesis. Application of designed structure of quadrature mirror digital filter bank can lead to bigger compression ration in lossy data compression.

The differential mobility classifier (DMC) is one of the core components in electrical mobility particle sizers for sizing sub-micrometer particles. Designing the DMC requires knowledge of the geometrical and constructional imperfection (or tolerance). Studying the effects of geometrical imperfection on the performance of the DMC is necessary to provide manufacturing tolerance and it helps to predict the performance of geometrically imperfect classifiers, as well as providing a calibration curve for the DMC. This thesis was accomplished via studying the cylindrical classifier and the parallel plate classifier. The numerical model was built using the most recent versions of COMSOL Multiphysics® and MATLAB®. For the cylindrical DMC, two major geometrical imperfections were studied: the eccentric annular classifying channel and the tilted inner cylinder/rod. For the parallel-plates DMC, the first study examined for the perfectly designed plates to optimize its dimensions and working conditions, while the second study conducted the plates’ parallelism. For both DMCs, a parametric study was conducted for several tolerances under various geometrical factors (i.e., channel length, width, spacing, cylinders radii, etc…), flow conditions (i.e., sheath-to-aerosol flow ratio, total flow rate), and several particles sizes. The results show that the transfer function deteriorated as the geometrical imperfection increased (i.e., the peak is reduced and the width at the half peak height is broadened). The parallel- plates DMC results show that the aspect ratio of the classifying channel cross-section (width-to-height) was recommended to be above 8. Particle diffusivity reduces the effect of geometrical imperfection, especially for particle sizes less than 10 nm.

Complex spatial relationships and patterns in multivariate data are relatively simple to identify visually but di cult to detect computation- ally. For this reason, Anivis, an interactive tool for visual exploration of multivariate quantitative pure serial periodic data was developed. The data has four dimensions depth, laterality, frequency and time. The data was visualized as an animated heatmap, by mapping depth and laterality to coordinates in a pixel grid and frequency to color. Transfer functions were devised to map a single variable to color through parametric curves. Anivis implemented heatmap generation through both weighted sum and deconvolution for comparison reasons. Deconvolution exhibited a to have better theoretical and practical performance. In addition to the heatmap visualization a scatter-plot was added in order to visualize the causal relationships between data points and high value areas in the heatmap visualization. Performance and applicability of the tool were tested and verified on experimental data from the Karolinksa Institute’s Department of Neuroscience. / Komplexa spatiala mo ̈nster och fo ̈rh ̊allanden i multivariat data a ̈r rel- ativt sv ̊ara att identifiera via bera ̈kningar men simpla att identifiera vi- suellt. Att visualisera data fo ̈r denna typ av data-analys anva ̈nds ofta i m ̊anga olika typer av fa ̈lt. Detta motiverade utvecklingen av Anivis; ett interaktivt verktyg fo ̈r visuell utforskning av multivariat kvantitativ data av neural aktivitet. Anivis anva ̈nder sig av dataset baserade p ̊a experi- mentell data fr ̊an en forskningsgrupp p ̊a Karolinska Institutets Institution fo ̈r Neurovetenskap. Dessa fyrdimensionella dataset best ̊ar av ma ̈tningar fr ̊an neuroner i form av deras position, aktivitet i form av frekvens och tidpunkt. Denna data anva ̈nds fo ̈r att generera en animerad heatmap, da ̈r neuroners frekvensva ̈rden visas i form av f ̈arg. Frekvensva ̈rdena om- vandlades till fa ̈rgva ̈rden via ̈overg ̊angsfunktioner som kopplar numeriska va ̈rden till fa ̈rgva ̈rden via parametriserade kurvor. Anivis lyckades imple- mentera tv ̊a olika metoder f ̈or att generera heatmap, viktade summor och dekonvolution. Dessa tv ̊a metoder ja ̈mfo ̈rdes med varandra, varav dekon- volution visade sig vara den teoretiskt och praktiskt e↵ektivaste meto- den. Utvecklingen av Anivis visade a ̈ven behovet fo ̈r ett punktdiagram fo ̈r att visualisera f ̈orh ̊allandet mellan ma ̈tta frekvensv ̈arden och spatial frekvensfo ̈rdelning i heatmappen.

Ce travail est une étude de caractérisation de différents composants du réseau basse tension (BT) français dans la bande de fréquence utilisée par les courants porteurs en ligne en bande étroite entre 9 kHz et 500 kHz. L’objectif est de permettre une compréhension approfondie de la propagation du signal CPL dans le réseau BT français. L’approche ascendante est choisie. Elle consiste en la caractérisation du réseau à partir de la caractérisation de chaque composant le constituant. Deux composants essentiels du réseau BT ont été caractérisés : les câbles d’énergie et les installations des clients. Dans la première partie, différentes technologies de câbles de distribution et de branchement ont été caractérisées expérimentalement. Deux modèles ont été choisis, un premier modèle dit ligne simple (LS) qui ne prend pas en compte le couplage et un deuxième modèle dit ligne couplée (LC) plus complet qui prend en compte le couplage inductif et capacitif entre les lignes de transmission des câbles. Dans la deuxième partie, on s’est intéressé à l’obtention des impédances d’entrée des installations des clients vues par le réseau BT. Ces impédances ont été obtenues à partir de la caractérisation du câble électrique domestique ainsi que celle de différents appareils domestiques parmi les plus présents dans les installations. Pour ces différentes caractérisations, trois méthodes expérimentales ont été conçues et mises au point. Une étude paramétrique a été réalisé pour évaluer l’influence des longueurs des câbles ainsi que les valeurs des impédances connectées aux extrémités des lignes de transmission de ces câbles sur l’atténuation, le couplage et l’impédance d’accès. / This work presents the characterization of different components of the French Low Voltage (LV) network in the frequency band used by the narrowband power line communication (PLC) between 9 kHz and 500 kHz. The aim of this work is to provide a deeper understanding of the propagation of the PLC signal in the French LV network. For this, the bottom-up approach is used. This approach consists in LV network characterization starting from the characterization of each component of this LV network. Two essential components of the LV network have been characterized: energy cables and customer installations. In the first part, different distribution and connection cable technologies have been experimentally characterized.Two models have been chosen: a first model called LS consisting on the characterization of cables without taking into account the coupling and a second one more complete called LC which, takes into account the inductive and capacitive coupling between the transmission lines of the cables. In the second part, the work focused on obtaining the input impedance of the customer installations seen by the LV network. These impedances were obtained from the characterization of the domestic electrical cable as well as various domestic appliances among the most present in the installations. Finally, the results of both parts allowed to make a parametric study of the influence of cable lengths and the impedance values connected to the ends of the transmission lines of these cables on attenuation, coupling and access impedances.

This thesis deals with imaging through diffuse media in coherence-controlled holographic microscope (CCHM) developed in IPE FME BUT. The mutual coherence function as well as the signal dependence on the lateral mutual shift between both arms of the CCHM are calculated. Both functions are related to each other. The latter dependence is measured experimentally. A principle of imaging with CCHM through diffuse media with both ballistic and diffuse light is explained by a simple geometrical model. This model is then verified experimentally by imaging a sample through diffuse medium. The point spread function (PSF) of CCHM for imaging through diffuse media is then calculated. Results of PSF calculation are proved experimentally.