<p>У овој дисертацији разматране су објективне мере процене квалитета<br />слике и видеа са потпуним и делимичним референцирањем на изворни<br />сигнал. За потребе евалуације квалитета развијене су поуздане,<br />рачунски ефикасне мере, засноване на очувању информација о<br />градијенту. Мере су тестиране на великом броју тест слика и видео<br />секвенци, различитих типова и степена деградације. Поред јавно<br />доступних база слика и видео секвенци, за потребе истраживања<br />формиране су и нове базе видео секвенци са преко 300 релевантних<br />тест узорака. Поређењем доступних субјективних и објективних скорова<br />квалитета показано је да је објективна евалуација квалитета веома<br />сложен проблем, али га је могуће решити и доћи до високих<br />перформанси коришћењем предложених мера процене квалитета слике<br />и видеа.</p> / <p>U ovoj disertaciji razmatrane su objektivne mere procene kvaliteta<br />slike i videa sa potpunim i delimičnim referenciranjem na izvorni<br />signal. Za potrebe evaluacije kvaliteta razvijene su pouzdane,<br />računski efikasne mere, zasnovane na očuvanju informacija o<br />gradijentu. Mere su testirane na velikom broju test slika i video<br />sekvenci, različitih tipova i stepena degradacije. Pored javno<br />dostupnih baza slika i video sekvenci, za potrebe istraživanja<br />formirane su i nove baze video sekvenci sa preko 300 relevantnih<br />test uzoraka. Poređenjem dostupnih subjektivnih i objektivnih skorova<br />kvaliteta pokazano je da je objektivna evaluacija kvaliteta veoma<br />složen problem, ali ga je moguće rešiti i doći do visokih<br />performansi korišćenjem predloženih mera procene kvaliteta slike<br />i videa.</p> / <p>This thesis presents an investigation into objective image and video quality<br />assessment with full and reduced reference on original (source) signal. For<br />quality evaluation purposes, reliable, computational efficient, gradient-based<br />measures are developed. Proposed measures are tested on different image<br />and video datasets, with various types of distorsions and degradation levels.<br />Along with publicly available image and video quality datasets, new video<br />quality datasets are maded, with more than 300 relevant test samples.<br />Through comparison between available subjective and objective quality<br />scores it has been shown that objective quality evaluation is highly complex<br />problem, but it is possible to resolve it and acchieve high performance using<br />proposed quality measures.</p>

Ce mémoire étudie l'algorithme d'amplification de l'amplitude et ses applications dans le domaine de test de propriété. On utilise l'amplification de l'amplitude pour proposer le plus efficace algorithme quantique à ce jour qui teste la linéarité de fonctions booléennes et on généralise notre nouvel algorithme pour tester si une fonction entre deux groupes abéliens finis est un homomorphisme. Le meilleur algorithme quantique connu qui teste la symétrie de fonctions booléennes est aussi amélioré et l'on utilise ce nouvel algorithme pour tester la quasi-symétrie de fonctions booléennes. Par la suite, on approfondit l'étude du nombre de requêtes à la boîte noire que fait l'algorithme d'amplification de l'amplitude pour amplitude initiale inconnue. Une description rigoureuse de la variable aléatoire représentant ce nombre est présentée, suivie du résultat précédemment connue de la borne supérieure sur l'espérance. Suivent de nouveaux résultats sur la variance de cette variable. Il est notamment montré que, dans le cas général, la variance est infinie, mais nous montrons aussi que, pour un choix approprié de paramètres, elle devient bornée supérieurement. / This thesis studies the quantum amplitude amplification algorithm and some of its applications in the field of property testing. We make use of the amplitude amplification algorithm to design an algorithm testing the linearity of Boolean functions which is more efficient than the previously best known quantum algorithm. We then generalize this new algorithm to test if a function between two finite abelian groups is a homomorphism. We improve on the previously best known algorithm for testing the symmetry of Boolean functions and use this new algorithm to test the quasi-symmetry of Boolean functions. Next, we further the study of the query complexity of the amplitude amplification algorithm for unknown initial amplitude. We give a rigorous description of the random variable representing the number of queries made by the algorithm and present the previously known result on its expected value upper bound. We then provide new results on the variance of this random variable. It is shown that, in the general case, the variance cannot be bounded above. We show, however, that it can be bounded for an appropriate choice of parameters.

This thesis is devoted to the rare decay π0 → e+ e− . We firstly introduce all theoretical knowledge necessary for the description of the vertices used in this work. Subsequently, we introduce three two-loop chiral Feynman diagrams, which are of order O(α2 p4 ). These diagrams are firstly decomposed to Master integrals by Laporta algorithm. After that, we calculate each Master integral individually by the differential equation technique. We also focus on the renormalization of the process. Since we are working with the effective field theory, finite corrections χ from counterterm diagrams naturally appear. With use of the calculations listed in this thesis, the determination of the parameter χR could be further improved taking into account the whole two-loop correction. 1

The growth in the number of wireless devices and applications underscores the need for characterizing and mitigating interference induced problems such as distortion and blocking. A typical interference scenario involves the detection of a small amplitude signal of interest (SOI) in the presence of a large amplitude interfering signal; it is desirable to attenuate the interfering signal while preserving the integrity of SOI and an appropriate dynamic range. If the frequency of the interfering signal varies or is unknown, an adaptive notch function must be applied in order to maintain adequate attenuation. This work explores the performance space of a phase cancellation technique used in implementing the desired notch function for communication systems in the 1-3 GHz frequency range. A system level model constructed with MATLAB and related simulation results assist in building the theoretical foundation for setting performance bounds on the implemented solution and deriving hardware specifications for the RF notch subsystem devices. Simulations and measurements are presented for a Low Noise Amplifer (LNA), voltage variable attenuators, bandpass filters and phase shifters. Ultimately, full system tests provide a measure of merit for this work as well as invaluable lessons learned. The emphasis of this project is the on-wafer LNA measurements, dependence of IC system performance on mismatches and overall system performance tests. Where possible, predictions are plotted alongside measured data. The reasonable match between the two validates system and component models and more than compensates for the painstaking modeling efforts. Most importantly, using the signal to interferer ratio (SIR) as a figure of merit, experimental results demonstrate up to 58 dB of SIR improvement. This number represents a remarkable advancement in interference rejection at RF or microwave frequencies.

Définies aux milieux des années 1990, les distributions de partons généralisées (GPDs) représentent un degré d'information supérieur aux facteurs de formes et fonctions de distributions de partons: en effet elles conservent la corrélation entre fraction d'impulsion longitudinale et position transverse des partons dans le nucléon. Par conséquent les GPDs permettent d'accéder à la distributions des partons dans le plan transverse en fonction de leur impulsion longitudinale. De plus il est possible de calculer le moment orbital angulaire total des quarks par le biais de la règle de somme de Ji. Nous accédons expérimentalement aux GPDs par des observables liées à des processus exclusifs (asymmétries, sections efficaces,...). Un programme expérimental mondial a commencé au début des années 2000 afin de caractériser les GPDs. Ce document décrit l'analyse de données de deux expériences réalisées en 2004 et 2010 dans le Hall A au laboratoire Jefferson en Virginie. A partir des données de 2004, nous avons extrait les sections efficaces d'électroproduction de photon polarisées et non polarisées. Une étude approfondie des erreurs systématiques a significativement améliorée la qualité des résultats. Ces derniers semblent indiquer la nécessité de prendre en compte les corrections de cible massive et de transfert d'impulsion fini jusqu'au twist-4. A partir des données 2010, nous avons réalisé pour la première fois une séparation des réponses longitudinale et transverse de l'électroproduction de pions neutres. Les résultats ont confirmé l'hypothèse d'une contribution transverse significative bien qu'étant de twist supérieur par rapport à la contribution longitudinale. Ces données de haute précision, que ce soit pour le photon ou le pion neutre, valident le formalisme des GPDs et permettront d'affiner les modèles afin de réaliser la tomographie 3D du nucléon. / Defined in the mid 90's, the generelized parton distributions (GPDs) represent a higher level of information than the form factors and parton distribution fuctions: indeed they encapsulate the correlation between the fraction of longitudinal momentum and the transverse position of the partons inside the nucleon. Consequently we can access the distribution of the partons in the transverse plane according to their longitudinal momentum. Moreover we can derive the total angular orbital momentum of quarks thanks to Ji's sum rule. Experimentally, we access the GPDs through the study of deep exclusive processes (asymmetries, cross sections,...). A worldwide experimental program started in the early 2000's. This thesis presents two data analyses carried on two data sets from experiments running at Jefferson laboratory - Hall A in 2004 and 2010. From the 2004 data set, we have extracted unpolarized and polarized photon electroproduction cross sections. A careful study of the systematic errors has greatly improved the quality of the results. They seem to indicate the necessity to take into account target-mass and finite-t corrections up to twist-4. From the 2010 data set, we have performed the first separation of the longitudinal and transverse responses of neutral pion electroproduction. The results confirm the assumption of a significant contribution of the transverse response although kinematically suppressed with respect to the longitudinal response. These results of high precision validate the GPD approach and will allow to improve the existing models.

Ce travail de thèse présente une étude sur les propriétés de nanostructures de type bâtonnets quantiques et de leur application pour les télécommunications optiques. Durant la dernière décennie, ces nanostructures, ont démontré des propriétés optiques et électroniques intéressantes en raison notamment d’un fort confinement quantique dans les trois dimensions d'espace. Cette thèse porte sur la conception et la fabrication d'émetteurs optiques intégrés à base de ce matériau et de leur implémentation dans des systèmes de communication. La première partie de ce travail analyse les propriétés de ces nanostructures, théorique et expérimentale. Elles sont utilisées comme matériau actif de lasers modulés directement en amplitude. Les propriétés dynamiques de ces lasers sont ensuite évaluées et des transmissions sur fibre optique entre 0 et 100 km sont ensuite démontrées en utilisant un filtre étalon permettant d’augmenter en particulier le taux d’extinction dynamique. En s’appuyant sur cette démonstration basée sur des éléments discrets, une version monolithique intégrant un laser et un résonateur en anneaux a été réalisée. La dernière partie de ce travail porte sur des lasers à blocage de mode à base de ce matériau et en particulier sur les méthodes d’intégration sur substrat InP. En particulier, un design de miroir de Bragg innovant a été développé à cet effet et une démonstration d'un laser a blocage de mode intégré avec un amplificateur optique à semi-conducteur a finalement été réalisée / This PhD dissertation presents a study on the properties of the novel quantum dash nanostructures and their properties for application in optical telecommunications. Over the last decade, scientific community has gained considerable interest over these nanostructures and several demonstrations have been made on their interesting optical and electronic properties, notably owing to their strong quantum confinement. This dissertation focuses on conception, fabrication and system demonstration of integrated optical transmitters based on quantum dash material. A first part of this work analyses the properties of qdashes theoretically and experimentally for their use as an active material in directly modulated lasers. The dynamic properties of this material are then evaluated leading to an optical transmission distances in range of 0-100km under direct modulation. The transmission is particularly studied with a passive optical filter to enhance the dynamic extinction ratio, the use of such passive filters is studied in detail. An innovative and fully integrated optical transmitter is finally demonstrated by integrating a ring-resonator filter to a distributed feedback laser. The second part of this work focuses on mode locked lasers based on this material and in particular the methods of integration of such devices on InP are explored. Thus an innovative Bragg mirror design is developed leading to a mode locked laser integrated with a semiconductor optical amplifier

Die Arbeit befasst sich mit der Erforschung und Anwendung der Kelvinsonden-Rasterkraftmikroskopie. Die Technik wird bezüglich der Quantität der gemessenen Werte und der erzielbaren lateralen Auflösung untersucht und auf diverse Probensysteme angewandt. Die so erhaltenen nanoskopischen Werte werden mit markoskopischen Messergebnissen verglichen. Sowohl die elektrostatische Kraft zwischen der Messspitze und der Probenoberfläche als auch deren Gradienten können zur Minimierung der elektrostatischen Wechselwirkung herangezogen werden. Die Detektion des Kraftgradienten zum Aufbau eines Regelkreises erweist sich gegenüber der Kraftdetektion überlegen. Die experimentell ermittelten Befunde werden durch eine Rechnersimulation bestätigt. Diese zeigt die Möglichkeit von quantitativen Ergebnissen für laterale Objektgrößen im Bereich von einigen Nanometern. Im Experiment kann dies gezeigt werden. Es folgt die Anwendung der Kelvinsonden-Rasterkraftmikroskopie: Nanoskopisch ermittelte Werte der Austrittsarbeitsänderung von Metalleinkristall-Oberflächen durch die Adsorption von C_60 entsprechen Literaturwerten, die mit makroskopisch messenden Methoden ermittelt wurden. Sich zeitlich ändernde Oberflächenpotentiale von einer organischen Solarzelle und von lateral unterschiedlich dotiertem Silizium lassen sich quantitativ messen. Der sich bei der Adsorption von Oktadezyl-Phosphonsäure auf Glimmer und Graphit bildende elektrostatische Dipol wird untersucht und abgebildet. Das Wachstumsverhalten und die Austrittsarbeit der organischen Moleküle PTCDA und Alq_3 auf den teilweise mit KBr bedeckten Metallsubstraten Au und Ag wird untersucht. Schlussendlich wird gezeigt, dass mit der Kelvinsonden-Rasterkraftmikroskopie sogar der molekülinterne Dipol der vier Butyl-Gruppen von Tetra-3,5-di-ter-butyl-phenyl-Porphyrinen aufgelöst werden kann.

Ce mémoire étudie l'algorithme d'amplification de l'amplitude et ses applications dans le domaine de test de propriété. On utilise l'amplification de l'amplitude pour proposer le plus efficace algorithme quantique à ce jour qui teste la linéarité de fonctions booléennes et on généralise notre nouvel algorithme pour tester si une fonction entre deux groupes abéliens finis est un homomorphisme. Le meilleur algorithme quantique connu qui teste la symétrie de fonctions booléennes est aussi amélioré et l'on utilise ce nouvel algorithme pour tester la quasi-symétrie de fonctions booléennes. Par la suite, on approfondit l'étude du nombre de requêtes à la boîte noire que fait l'algorithme d'amplification de l'amplitude pour amplitude initiale inconnue. Une description rigoureuse de la variable aléatoire représentant ce nombre est présentée, suivie du résultat précédemment connue de la borne supérieure sur l'espérance. Suivent de nouveaux résultats sur la variance de cette variable. Il est notamment montré que, dans le cas général, la variance est infinie, mais nous montrons aussi que, pour un choix approprié de paramètres, elle devient bornée supérieurement. / This thesis studies the quantum amplitude amplification algorithm and some of its applications in the field of property testing. We make use of the amplitude amplification algorithm to design an algorithm testing the linearity of Boolean functions which is more efficient than the previously best known quantum algorithm. We then generalize this new algorithm to test if a function between two finite abelian groups is a homomorphism. We improve on the previously best known algorithm for testing the symmetry of Boolean functions and use this new algorithm to test the quasi-symmetry of Boolean functions. Next, we further the study of the query complexity of the amplitude amplification algorithm for unknown initial amplitude. We give a rigorous description of the random variable representing the number of queries made by the algorithm and present the previously known result on its expected value upper bound. We then provide new results on the variance of this random variable. It is shown that, in the general case, the variance cannot be bounded above. We show, however, that it can be bounded for an appropriate choice of parameters.

Signal processing has been playing a key role in providing solutions to key problems encountered in communications, in general, and in wireless communications, in particular. Time-Frequency Signal Processing (TFSP) provides eective tools for analyzing nonstationary signals where the frequency content of signals varies in time as well as for analyzing linear time-varying systems. This research aimed at exploiting the advantages of TFSP, in dealing with nonstationary signals, into the fundamental issues of signal processing, namely the signal estimation and signal separation. In particular, it has investigated the problems of (i) the Instantaneous Frequency (IF) estimation of Linear Frequency-Modulated (LFM) signals corrupted in complex-valued zero-mean Multiplicative Noise (MN), and (ii) the Underdetermined Blind Source Separation (UBSS) of LFM signals, while focusing onto the fast-growing area of Wireless Communications (WCom). A common problem in the issue of signal estimation is the estimation of the frequency of Frequency-Modulated signals which are seen in many engineering and real-life applications. Accurate frequency estimation leads to accurate recovery of the true information. In some applications, the random amplitude modulation shows up when the medium is dispersive and/or when the assumption of point target is not valid; the original signal is considered to be corrupted by an MN process thus seriously aecting the recovery of the information-bearing frequency. The IF estimation of nonstationary signals corrupted by complex-valued zero-mean MN was investigated in this research. We have proposed a Second-Order Statistics approach, rather than a Higher-Order Statistics approach, for IF estimation using Time-Frequency Distributions (TFDs). The main assumption was that the autocorrelation function of the MN is real-valued but not necessarily positive (i.e. the spectrum of the MN is symmetric but does not necessary has the highest peak at zero frequency). The estimation performance was analyzed in terms of bias and variance, and compared between four dierent TFDs: Wigner-Ville Distribution, Spectrogram, Choi-Williams Distribution and Modified B Distribution. To further improve the estimation, we proposed to use the Multiple Signal Classification algorithm and showed its better performance. It was shown that the Modified B Distribution performance was the best for Signal-to-Noise Ratio less than 10dB. In the issue of signal separation, a new research direction called Blind Source Separation (BSS) has emerged over the last decade. BSS is a fundamental technique in array signal processing aiming at recovering unobserved signals or sources from observed mixtures exploiting only the assumption of mutual independence between the signals. The term "blind" indicates that neither the structure of the mixtures nor the source signals are known to the receivers. Applications of BSS are seen in, for example, radar and sonar, communications, speech processing, biomedical signal processing. In the case of nonstationary signals, a TF structure forcing approach was introduced by Belouchrani and Amin by defining the Spatial Time- Frequency Distribution (STFD), which combines both TF diversity and spatial diversity. The benefit of STFD in an environment of nonstationary signals is the direct exploitation of the information brought by the nonstationarity of the signals. A drawback of most BSS algorithms is that they fail to separate sources in situations where there are more sources than sensors, referred to as UBSS. The UBSS of nonstationary signals was investigated in this research. We have presented a new approach for blind separation of nonstationary sources using their TFDs. The separation algorithm is based on a vector clustering procedure that estimates the source TFDs by grouping together the TF points corresponding to "closely spaced" spatial directions. Simulations illustrate the performances of the proposed method for the underdetermined blind separation of FM signals. The method developed in this research represents a new research direction for solving the UBSS problem. The successful results obtained in the research development of the above two problems has led to a conclusion that TFSP is useful for WCom. Future research directions were also proposed.

H TMS διακρίνεται έναντι άλλων εργαλείων απεικόνισης λόγω της ικανότητάς της να ενεργοποιεί νευρώνες σε επιλεγμένες φλοιϊκές περιοχές. Η παρούσα μελέτη προσπαθεί να διερευνήσει το νευροφυσιολογικό προφίλ της μυικής προκλητής απάντησης διάμεσου διακρανιακής μαγνητικής διέγερσης (TMS) σε ένα σεβαστό αριθμό ασθενών με σχιζοφρένεια υπό φαρμακευτική αγωγή. Σε 51 ασθενείς υπό φαρμακευτική αγωγή και διάγνωση σχιζοφρένειας και 51 υγιείς μάρτυρες απόλυτα σύμφωνους ως προς το φύλο, το ύψος και την ηλικία με τους ασθενείς που συμμετείχαν καταγράφηκαν κινητικά προκλητά δυναμικά (ΜΕΡ) από τον απαγωγό μυ του αντίχειρα μετά τον ερεθισμό του αντίπλευρου κινητικού φλοιού με ένα κυκλικό πηνίο. Μετρήθηκαν: w RMTh (resting motor threshold): Ο ουδός κινητικής ηρεμίας w SI-max (stimulus intensity for maximum MEP): Η ένταση ερεθίσματος που χρειάζεται για την καταγραφή του μέγιστου κινητικού προκλητού δυναμικού w Post-stimulus silent period: Την ανερέθιστη περίοδο που επάγεται μετά από ένα ερέθισμα που προκαλεί συγκεκριμένη μυική δραστηριότητα w MEP Latency: Λανθάνον χρόνος των κινητικών προκλητών δυναμικών MEP amplitude: Το εύρος των κινητικών προκλητών δυναμικών. Τα βασικά ευρήματα είναι η σαφώς υψηλότερη από τις φυσιολογικές τιμές, τιμή των RMTh και SI-max και τα δύο, ενδείξεις νευρωνικής ευοδωτικής δραστηριότητας στους ασθενείς σε σύγκριση με τους μάρτυρες. Ειδικότερα στην ομάδα των ασθενών που βρίσκονται σε θεραπεία με ζιπρασιδόνη παρουσιάστηκε το υψηλότερο SI-max και στα δύο ημισφαίρια και το υψηλότερο RMTh στο αριστερό ημισφαίριο. Οι ασθενείς στην ομάδα που ελάμβαναν ολανζαπίνη παρουσίασαν το χαμηλότερο RMTh για το αριστερό ημισφαίριο και αυτοί σε θεραπεία με κουατιεπίινη παρουσίασαν τιμές ανάμεσα στις τιμές των δύο προηγούμενων ομάδων. Όταν χρησιμοποιήθηκε ένταση ερεθίσματος (SI) σχετικής τιμής με το RMTh, η ανερέθιστη περίοδος βρέθηκε μεγαλύτερη στους ασθενείς από ότι στους μάρτυρες ενώ δεν παρατηρήθηκε καμία διαφορά ανάμεσα στις δύο μεγάλες ομάδες ασθενών και μαρτύρων όταν χρησιμοποιήθηκε σταθερής έντασης ερέθισμα (SI). Συμπεράναμε, ότι οι αλλαγές στις παραμέτρους που μετρήθηκαν, μπορούν να εξηγηθούν από βασικές μεταβολές της ενδοφλοιϊκής ευοδωτικής κινητικής δραστηριότητας που ακολουθείται από διαφοροποιήσεις της φλοιϊκής αναστολής, οι οποίες μπορούν να αποδοθούν είτε στην σχιζοφρένεια είτε στην φαρμακευτική αγωγή ή στην αλληλεπίδρασή τους. / Trancranial magnetic stimulation (TMS) provides a non-invasive means for exploring physiological alterations of central motor control in a variety of neuropsychiatric diseases. The present study aimed to assess the neurophysiological profile of muscle evoked responses to a standard TMS procedure in a considerable number of medicated patients with schizophrenia. Fifty-one patients with diagnosis of schizophrenia and 51 sex- and age-matched healthy subjects were enrolled in the study. Motor evoked potential (MEP) from abductor pollicis brevis muscle was elicited by stimulation of the contralateral motor cortex with a circular coil. The hot-spot was marked. Were measured: ¨ the resting motor threshold (RMTh), ¨ the stimulus intensity for maximum MEP (SI-max), ¨ the post-stimulus silent period of voluntary muscle activity and ¨ MEP latency and amplitude. The main findings were the significantly higher than normal values for RMTh and SI-max, which are both indices of neuronal excitability. In particular, patients who had ziprasidone in their therapeutic regimen demonstrated the highest SI-max for both hemispheres and highest RMTh for left hemisphere, patients receiving olanzapine demonstrated the lowest RMTh for left hemisphere and those on quetiapine showed intermediate values. Silent period was longer in the patients as opposed to controls when a RMTh-related SI was used and did not differ between the two groups when a fixed SI was used. We concluded that the observed TMS changes could be interpreted by primary alterations of intracortical motor excitability followed by defects of cortical inhibition and should be attributed to schizophrenia, antipsychotic medication or the interaction between both factors.