Popularity of speech communication is rapidly increasing in various contexts such as conferencing systems, mobile/fixed electronic devices and laptops thus leading to a heightened demand for new services and improved speech quality. Dictaphones used for dictations usually have one microphone. Single microphone does not give enough degree of freedom to allow estimation of location of the source. Microphone array makes use of multiple microphones for spatial filtering suppressing the background noise. This report aims for speech enhancement utilizing the benefits inherited with microphone arrays to find direction of desired speaker and focus the listening beam in that direction. A comparison is made between Generalized Cross Correlation (GCC) methods for locating the source in real office environment. Beamforming is implemented to make the microphone array listen in the desired direction thus reducing the interference from other sources. Minimum Variance Distortion-less Response (MVDR) approach is shown to give better results compared to more simplistic techniques. Perceptual based Eigen filter incorporating human hearing models in subspace incorporated in the suppressor eliminates the residual noise. Objective system performance is evaluated by estimating Signal-to-Noise-Ratio improvement (SNRI), segmental SNR, signal degradation and noise suppression. Perpetual Evaluation of Speech Quality (PESQ) gives Mean Opinion Score for subjective evaluation. / asim_zolo@yahoo.com, akbarali45@gmail.com

Les myopathies auto-immunes (MAI), classiquement appelées myosites ou myopathies inflammatoires idiopathiques, représentent un groupe de maladies définies par des caractéristiques cliniques, histopathologiques et biologiques. Une des caractéristiques les plus notables est la présence d’auto-anticorps (aAc) chez environ 60% des patients. Les MAI regroupent : les dermatomyosites, les polymyosites, les myosites à inclusion, les myosites de chevauchement incluant le syndrome des anti-synthétases et les myopathies nécrosantes auto-immunes (MNAI). Les MNAI ont été récemment individualisées parmi les MAI comme des maladies graves fréquemment associées à la présence d’aAc dirigés contre la Signal Recognition Particle (SRP) ou la 3-Hydroxy-3-MéthylGlutaryl-CoA Réductase (HMGCR). La localisation de SRP et HMGCR étant intracellulaire, le rôle des aAc dans la physiopathologie des MNAI reste mal compris. La pathogénicité des aAc anti-SRP et anti-HMGCR envers des cellules musculaires cultivées in vitro a récemment été mise en évidence mais leurs effets in vivo demeurent inconnus.Au cours de cette thèse, j’ai étudié le rôle physiopathologique des aAc anti-SRP et anti-HMGCR in vivo chez la souris. Le transfert passif d’IgG de patients atteints de MNAI, positifs pour les aAc anti-SRP ou anti-HMGCR, à la souris sauvage entraîne un déficit musculaire. Ce déficit était prolongé chez la souris immunodéficiente Rag2-/-, et limité chez la souris déficiente pour la fraction C3 du complément. Chez les souris recevant les IgG anti-SRP+, le déficit musculaire était important et accompagné de quelques signes de nécrose myocytaire. Les IgG anti-HMGCR+ induisaient une faiblesse musculaire moindre, et des signes histopathologiques rares ou absents. Ces résultats sont en accord avec l’observation chez l’homme d’une maladie plus grave chez les patients anti-SRP+ par rapport aux patients anti-HMGCR+. La supplémentation en complément humain des souris augmentait le déficit musculaire induit par les IgG anti-HMGCR+ et de façon moindre pour les IgG anti-SRP+. En collaboration avec l’INSERM UMRS974, nous avons montré que les cibles SRP et HMGCR peuvent être détectées à la surface des fibres musculaires in vitro, suggérant qu’elles puissent être accessibles aux aAc in vivo.Ces résultats démontrent pour la première fois le rôle pathogène des aAc anti-SRP et anti-HMGCR in vivo et l’implication du complément, contribuant à une avancée dans la compréhension de la physiopathologie des MNAI. / Autoimmune myopathies (AIM), classically called myositis or idiopathic inflammatory myopathies, represent a group of diseases characterized by clinical, histopathologic and biologic properties. One of the most notable properties is the presence of autoantibodies (aAb) in approximately 60% of patients. AIM includes five principal entities: dermatomyositis, polymyositis, inclusion body myositis, overlap myositis including the anti-synthetase syndrome and immune-mediated necrotizing myopathies (IMNM). IMNM have recently been individualized among AIM as severe diseases frequently associated with aAb directed against Signal Recognition Particle (SRP) or 3-Hydroxy-3-MethylGlutaryl-CoA Reductase (HMGCR). Since SRP and HMGCR have an intracellular localization, the role of anti-SRP and anti-HMGCR aAb in the pathophysiology of IMNM remains unclear. Anti-SRP and anti-HMGCR aAb were recently shown to be pathogenic to muscle cells in vitro but in vivo effects remain unknown.During this thesis, I studied the pathophysiological role of anti-SRP and anti-HMGCR aAb in vivo in mice. Passive transfer of IgG purified from plasma of IMNM patients positive for anti-SRP and anti-HMGCR aAb to wild-type mice elicited a muscle weakness. Immune-deficient Rag2-/- mice presented a prolonged muscle deficit, whereas complement component C3 deficient mice had limited signs. Mice injected with anti-SRP+ IgG displayed a strong muscle weakness with mild myocytic necrosis. The muscle deficit was milder and histopathologic findings were not always present in mice receiving anti-HMGCR+ IgG. This is in accordance with clinical findings in anti-SRP+ patients which present a more severe disease than anti-HMGCR+ patients. When supplemented with human complement, mice receiving anti-HMGCR+ IgG showed a more severe muscle deficit. This supplementation increased the deficit induced by anti-SRP IgG in a milder way. In collaboration with INSERM UMRS974, we showed that the targets SRP and HMGCR can be detected on the surface of myofibres in vitro, suggesting that they could be accessible to aAb in vivo.Together, these results demonstrate for the first time the pathogenic role of anti-SRP and anti-HMGCR aAb in vivo and the implication of complement, contributing to a progress in the comprehension of MNAI pathophysiology.

This thesis is related to the field of acoustic signal processing and its applications to emerging communication environments. Acoustic signal processing is a very wide research area covering the design of signal processing algorithms involving one or several acoustic signals to perform a given task, such as locating the sound source that originated the acquired signals, improving their signal to noise ratio, separating signals of interest from a set of interfering sources or recognizing the type of source and the content of the message. Among the above tasks, Sound Source localization (SSL) and Automatic Speech Recognition (ASR) have been specially addressed in this thesis. In fact, the localization of sound sources in a room has received a lot of attention in the last decades. Most real-word microphone array applications require the localization of one or more active sound sources in adverse environments (low signal-to-noise ratio and high reverberation). Some of these applications are teleconferencing systems, video-gaming, autonomous robots, remote surveillance, hands-free speech acquisition, etc. Indeed, performing robust sound source localization under high noise and reverberation is a very challenging task. One of the most well-known algorithms for source localization in noisy and reverberant environments is the Steered Response Power - Phase Transform (SRP-PHAT) algorithm, which constitutes the baseline framework for the contributions proposed in this thesis. Another challenge in the design of SSL algorithms is to achieve real-time performance and high localization accuracy with a reasonable number of microphones and limited computational resources. Although the SRP-PHAT algorithm has been shown to be an effective localization algorithm for real-world environments, its practical implementation is usually based on a costly fine grid-search procedure, making the computational cost of the method a real issue. In this context, several modifications and optimizations have been proposed to improve its performance and applicability. An effective strategy that extends the conventional SRP-PHAT functional is presented in this thesis. This approach performs a full exploration of the sampled space rather than computing the SRP at discrete spatial positions, increasing its robustness and allowing for a coarser spatial grid that reduces the computational cost required in a practical implementation with a small hardware cost (reduced number of microphones). This strategy allows to implement real-time applications based on location information, such as automatic camera steering or the detection of speech/non-speech fragments in advanced videoconferencing systems. As stated before, besides the contributions related to SSL, this thesis is also related to the field of ASR. This technology allows a computer or electronic device to identify the words spoken by a person so that the message can be stored or processed in a useful way. ASR is used on a day-to-day basis in a number of applications and services such as natural human-machine interfaces, dictation systems, electronic translators and automatic information desks. However, there are still some challenges to be solved. A major problem in ASR is to recognize people speaking in a room by using distant microphones. In distant-speech recognition, the microphone does not only receive the direct path signal, but also delayed replicas as a result of multi-path propagation. Moreover, there are multiple situations in teleconferencing meetings when multiple speakers talk simultaneously. In this context, when multiple speaker signals are present, Sound Source Separation (SSS) methods can be successfully employed to improve ASR performance in multi-source scenarios. This is the motivation behind the training method for multiple talk situations proposed in this thesis. This training, which is based on a robust transformed model constructed from separated speech in diverse acoustic environments, makes use of a SSS method as a speech enhancement stage that suppresses the unwanted interferences. The combination of source separation and this specific training has been explored and evaluated under different acoustical conditions, leading to improvements of up to a 35% in ASR performance. / Martí Guerola, A. (2013). Multichannel audio processing for speaker localization, separation and enhancement [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/33101

Το κάτωθι κείμενο πραγματεύεται το φαινόμενο της εξάπλωσης αυτοαναπαραγόμενων αυτομάτων σε δίκτυα. Αρχικά προβαίνουμε σε μια εισαγωγή στα αυτοαναπαραγόμενα προγράμματα και στο περιβάλλον στο οποίο εξαπλώνονται και εν συνεχεία εμβαθύνουμε στον τρόπο με τον οποίο προσεγγίζουμε το φαινόμενο. Μελετάμε μεθόδους ανίχνευσης με χρήση φίλτρων Kalman και εντροπίας. Τέλος, ασχολούμαστε με μια σειρά παιγνίων και σεναρίων με σκοπό την ανάδειξη συγκεκριμένων πλευρών του όλου προβλήματος και την τροπή που παίρνει στις μέρες μας. Εν κατακλείδι, η παρούσα διπλωματική εργασία τονίζει βασικές ιδιότητες που χαρακτηρίζουν την διάδοση και εισάγει νέες βοηθητικές έννοιες και μοντέλα, με στόχο την κατανόηση και τον ενστερνισμό του πνεύματος των εξελίξεων στα σύγχρονα worms και viruses. / The text below considers the phenomenon of propagation of self replicating automata. We begin with an introduction to self replicating programs and to the environment in which they propagate and then we delve and explain the ways of approaching the phenomenon. We study detection methods via the use of Kalman filters and estimation of entropy. Finally, a series of games and scenarios are introduced and studied, in order to enlighten certain aspects of the problem and its current direction. In conclusion, this diploma thesis marks basic properties of the propagation and introduces auxiliary concepts and new models, having as a goal the comprehension and the adoption of the spirit of evolution of modern worms and viruses.

Acoustic Sound Source localization using signal processing is required in order to estimate the direction from where a particular acoustic source signal is coming and it is also important in order to find a soluation for hands free communication. Video conferencing, hand free communications are different applications requiring acoustic sound source localization. This applications need a robust algorithm which can reliably localize and position the acoustic sound sources. The Steered Response Power Phase Transform (SRP-PHAT) is an important and roubst algorithm to localilze acoustic sound sources. However, the algorithm has a high computational complexity thus making the algorithm unsuitable for real time applications. This thesis focuses on describe the implementation of the SRP-PHAT algorithm as a function of source type, reverberation levels and ambient noise. The main objective of this thesis is to present different approaches of the SRP-PHAT to verify the algorithm in terms of acoustic enviroment, microphone array configuration, acoustic source position and levels of reverberation and noise.

The aim of this thesis is to study state regulation of anti-democratic parties, i.e. party regulation. The term ‘Party regulation’ refers to laws that may regulate the activities and behavior of political parties. This thesis uses a comparative method, conducted on three European countries which regulate anti-democratic parties differently. The cases studied are Germany, Spain and Sweden.The basis for understanding state regulation of anti-democratic parties rests on a historical institutionalist perspective along with theories of democratic tolerance. The analysis reveals that states regulate anti-democratic parties differently as a result of their historical past which has made them adopt different ideas of how political parties should be seen. Further, the analysis shows that there is no connection between the party regulation adopted and the effect it has on the anti-democratic parties.

This thesis explores methodologies of modeling and evaluating the operational performance of a typical aeroengine having field experience over two decades. Upon failure, the engine is repaired and restored to flight worthy condition and hence comes under the purview of repairable systems. Operational performance of the engine is being measured in terms of five functions of time, namely, M(t), which is the expected number of system failures in the time interval [0,t]; system failure rate m(t), which is an unconditional quantity and is simply the derivative of M(t); ρ(t), the conditional failure intensity given the history of a system Ht, which is nothing but limdt→1 Prob(System fails in [t,t + dt] |Ht); and M′(t) and m′(t), which are 0 dt conditional entities analogous to M(t) and m(t) defined in the same spirit as that of ρ(t), the details of which are given in the third chapter of the thesis. These functions are being estimated using field failure-repair data of 418 aeroengines, where the observations on time between failures are being measured in number of flying hours logged in between failures, and the corresponding repair duration is being measured in number of calendar days. To start with, using the superimposed renewal process model the above quantities M(t), m(t), m′(t), M′(t) and ρ(t) are estimated both in the frequentist as well as the Bayesian framework. Subsequently repair times have been incorporated into the model and analysed using both frequentist and Bayesian approaches. Next, the model of Lawless and Thiagarajah (1996) which incorporates both renewal and time trend, has been generalized to include repair time as well, and a comprehensive methodology of Bayesian model selection under this model has been developed. After introducing the research problem in the first chapter, the engineering system description leading to the identification of the failure modes, repair practice and the variables of interest is taken up in the following chapter at the outset, as a pre-requisite to the stochastic modeling and the statistical analysis that to follow in the remainder of the thesis. As the first stochastic model, the number of system failures in a given time interval is modeled as a superimposed renewal process with the constituent independent renewal processes running in different component sockets having Weibull inter failure times. This model is first empirically validated using the field failure data and then using this model, the five quantities of interest as mentioned above viz. M(t), m(t), ρ(t), M′(t) and m′(t) are analysed from a frequentist maximum likelihood perspective. A Bayesian analysis of the same follows in the subsequent chapter. Next, the repair effect is incorporated into the superimposed renewal process model by considering the Weibull parameters of inter failure times of the constituent renewal processes running in independent component sockets as a polynomial in the last repair time. The nature of this polynomial relationships are empirically deter-mined and the Weibull assumption is validated through a test of hypothesis. Different polynomial relationships lead to consideration of several models, with the correct ones chosen through a series of likelihood ratio tests. Next based on the appropriate models a maximum likelihood analysis of M(t), ρ(t) and M′(t) has been carried out. Like the simple superimposed renewal process model, Bayesian analysis of this model incorporating repair times is carried out in the following chapter. In the Bayesian setup however, the problem of model selection could be kept unrestricted to non-nested models as well (unlike the previous chapter, where only nested models could be considered), and a comprehensive model selection exercise has been carried out with the aid of intrinsic Bayes factors and training data sets. The last but one chapter presents a generalised model of Lawless and Thiagarajah (1996) for performance evaluation of aeroengines that incorporate renewals, time trends and the repair characteristics. Here also since the primary problem is one of model selection, the entire analysis like in the preceding chapter has been carried out under the Bayesian frame-work. The final chapter concludes the thesis by comparing the empirical results obtained in the previous five chapters, summarising the main contributions of the thesis and providing directions for future research.

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L'utilisation optimale, dans des applications spécifiques, des Détecteurs Silicium nécessite une connaissance approfondie des phénomènes physiques sous-jacents. Dans ce mémoire, cette idée conductrice est appliquée à deux types de détecteurs : (1) les SiPM et leurs applications en imagerie médicale (2) les détecteurs à pixels planaires (PPS) et leurs applications dans la mise-à-jour du détecteur interne d'ATLAS pour le LHC à haute luminosité. Mon travail personnel sur les SiPM a débuté il y a environ 10 ans. Ainsi la partie (A) de mon HDR rappelle tout d'abord le principe physique de la photodiode à avalanche en mode Geiger (GM-APD), qui constitue la cellule élémentaire d'un SiPM. Puis le fonctionnement du SiPM est développé, avec ses principales caractéristiques physiques, ainsi que les montages expérimentaux mis en œuvre et les mesures de ces paramètres sur les productions des principaux fabricants. La dépendance en température des paramètres des SiPM constitue un inconvénient majeur dans certaines applications, aussi mon travail personnel montre comment on peut en grande partie s'affranchir de cette dépendance, en contrôlant certains paramètres de fonctionnement. Les détecteurs à SiPM présentent des avantages très intéressants au plan électrique, optique, mécanique, etc ..., permettant des applications multiples dans des domaines où une grande surface de détection est requise. Ainsi, les matrices de SiPM sont des composants très attractifs pour des applications d'imagerie médicale. Mon travail dans deux applications de ce type est détaillé : PET à haute résolution pour des petits animaux, et détecteur de radiation portatif pour l'aide à la localisation in situ de tumeurs solides. En parallèle à l'activité SiPM, j'ai été impliquée ces dernières années dans la conception et la caractérisation de nouveaux détecteurs à pixel planaires pour "l'upgrade" de l'expérience ATLAS. La partie (B) de mon HDR expose ainsi les méthodes expérimentales, comme "Secondary Ion Mass Spectrometry (SIMS)" et "Spreading Resistance Profiling" (SRP), utilisées pour la mesure de profils de dopage pour le détecteurs PPS. Je démontre ainsi l'importance de ces mesures pour le contrôle du process de fabrication, et la calibration des simulations TCAD (Technology-Computed Aided Design). Les résultats des simulations prévoyant le comportement des nouveaux détecteurs planaires proposés, avec des caractéristiques géométriques et une résistance aux radiations améliorées, sont présentés.

<p>The objective of this thesis is to design and implement a small scaleInternet Service Provider (ISP) for the NetCenter sub department atMälardalen University. The ISP is intended to give NetCenter a networkseparate from the University’s network, providing them with a moreflexible environment for lab purposes. This will give their students anopportunity to experience a larger backbone with Internet accessibility,which has not been previously available. At the same time it will place theteachers in control of the network in the NetCenter lab premises.The network is designed with a layered approach including an Internetaccess layer, a larger core segment and a distribution layer with aseparated lab network. It also incorporates both a public and a privateserver network, housing servers running e.g. Windows Active Directory,external DNS services, monitoring tools and logging applications. TheInternet access is achieved by peering with SUNET providing a full BGPfeed.This thesis report presents methods, implementations and results involvedin successfully creating the NetCenter ISP as both a lab network and anInternet provider with a few inevitable shortcomings; the most prominentbeing an incomplete Windows Domain setup.</p>