La génération d’harmoniques d’ordre élevé est un processus d’interaction lumière-matière hautement non-linéaire permettant la synthèse d’impulsions sub-femtosecondes, dites attosecondes (1 as = 10⁻¹⁸ s). Mes travaux de thèse portent sur l’étude du transfert de moment angulaire lors de ce processus, afin de contrôler les caractéristiques spatiales et de polarisation du rayonnement émis dans l’extrême ultraviolet. Comme pour la matière, le moment angulaire de la lumière peut être séparé en une composante de spin, associée à l’état de polarisation du faisceau, et une composante orbitale, reliée à la forme du front d’onde. La maitrise complète du moment angulaire des harmoniques nécessite de recourir à des schémas de génération à deux faisceaux non-colinéaires, créant un réseau de diffraction dans le milieu générateur. Nous avons montré que, bien que les règles de transfert obéissent à des lois de conservation du moment angulaire, la description fine du phénomène requiert une analyse précise du champ laser dans le milieu de génération. Ces travaux ouvrent des perspectives de mise en forme avancée des impulsions attosecondes. / High-order harmonic generation is a highly nonlinear laser-matter interaction process which allows the synthesis of sub-femtosecond pulses, also called attosecond (1 as = 10⁻¹⁸ s) pulses. My PhD is centered around the study of angular momentum transfer during this process, in order to control spatial and polarization features of the radiation which is emitted in the extreme ultraviolet. As for matter, the angular momentum of light can be divided into a spin component, associated with the beam’s polarization, and an orbital component, related to the shape of the wavefront. The control of high harmonics’ angular momentum requires generating schemes involving two crossing beams, thus creating a diffraction grating in the generating medium.We have shown that, although the transfer rules obey conservation laws of the angular momentum, the fine description of the phenomenon requires an accurate analysis of the laser field in the generation medium. This work opens the road for advanced shaping of attosecond pulses.

Inom ett företag eller en organisation finns det stor nytta av intranät som ett arbetsverktyg för att kunna dela information. Ett välfungerat intranät bidrar till ett bättre informationsflöde och ett effektivare samarbete. SharePoint är en plattform för intranät med interaktiva funktioner. Omnia är ett ramverk anpassad för Microsofts SharePoint 2013.I detta arbete undersöks hur Omnia fungerar som ett ramverk och vad produkten lämpar sig för. Omnia ramverket utvärderades noggrant och en oberoende bedömning utfördes under examensarbetet. Utvärderingen var baserad på vetenskapliga undersökningar som byggde på den kvalitativa och kvantitativa forskningsmetodiken. Utvärderingens huvudområden baserades på systemets prestanda, skalbarhet, arkitektur och funktionalitet. En testprototyp utvecklades under arbetets gång genom Omnia i from av en webbaserad applikation.Ramverket Omnia var lämplig för utveckling av interaktiva webbaserade applikationer för intranät i SharePoint. Dock saknade den färdig dokumentation/API, vilket gjorde utvecklingsprocessen mer avancerad. Lösningsarkitekturen för systemet uppfyllde kraven för skalbara system, eftersom den baserades på lagerarkitektur. Systemet hade även bra prestanda, dock försämrades den efter att antalet användare översteg ettusen. Funktionaliteten testades med hjälp av två olika tester, vilket visade att produkten är lämplig för att användas i intranät. / The functionality was tested by two different tests, which showed that the product is suitable for usage in the intranet within a company or an organization, there are great benefits from using intranet as a tool for sharing of information. A good intranet contributes to a better flow of information and effective cooperation. SharePoint is a platform for intranet with interactive features, it makes the job easier for staff and even the company. The framework Omnia is a solution designed for Microsoft SharePoint 2013.This essay evaluates how Omnia acts as a framework and what the product is suitable for. Omnia framework evaluates carefully and is an independent assessment carried during this essay. The evaluation is based on scientific studies which are based on the qualitative and quantitative research methodology. The evaluator's main areas are based on system performance, scalability, architecture and functionality. A test prototype develops during the process in the form of an employee vacation request application by the development framework Omnia.The framework Omnia is considered to be suitable for the development of interactive web-based applications for SharePoint. The architecture for the system meets the requirements for scalable systems because it is based on the tier architecture. The system also has good performance but it needs to be improved if the number of users exceeds one thousand. The functionality of this product is quite suitable for the system's usage.

Doctor of Philosophy / Department of Physics / Tim Bolton / This thesis represents the first study of the helicity distributions of Z[gamma] di-boson production at hadron colliders. I use 5 fb⁻¹ of [radical]s = 7 TeV center of mass energy proton-proton collision data, collected by the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC), to look at the angular distribution of the Z[gamma] [right arrow] e⁺e⁻[gamma] / [mu]⁺ [mu]⁻ [gamma] process and measure the helicity amplitudes that govern it. This study provides sensitivity to the interference terms between different quantum states and through the interference terms to the possible new physics. The final state is comprised of leptons (muon-antimuon or electron-positron pairs) with transverse momentum over 20 GeV and a photon with transverse energy over 30 GeV. Helicty amplitudes are measured for the total angular momentum of the quark-antiquark system up to J[subscript]q[subscript bar]q = 2. Four-dimensional multivariate analysis of the 2011 CMS data shows no significant deviations from the standard model prediction for the measured amplitudes.

Le début des années 2000 a vu la cartographie du génome humain se réaliser après 13 ans de recherche. Le défi du prochain siècle réside dans la construction du connectome humain, qui consiste à cartographier les connexions du cerveau en utilisant l’imagerie par résonance magnétique (IRM) de diffusion. Cette technique permet en effet d’étudier la matière blanche du cerveau de façon complètement non invasive. Bien que le défi soit monumental, la résolution d’une image d’IRM se situe à l’échelle macroscopique et est environ 1000 fois inférieure à la taille des axones qu’il faut cartographier. Pour aider à pallier à ce problème, ce mémoire propose une nouvelle technique de débruitage spécialement conçue pour l’imagerie de diffusion. L’algorithme Non Local Spatial and Angular Matching (NLSAM) se base sur les principes du block matching et du dictionary learning pour exploiter la redondance des données d’IRM de diffusion. Un seuillage sur les voisins angulaire est aussi réalisé à l’aide du sparse coding, où l’erreur de reconstruction en norme l2 est bornée par la variance locale du bruit. L’algorithme est aussi conçu pour gérer le biais du bruit Ricien et Chi non centré puisque les images d’IRM contiennent du bruit non Gaussien. Ceci permet ainsi d’acquérir des données d’IRM de diffusion à une plus grande résolution spatiale que présentement disponible en milieu clinique. Ce travail ouvre donc la voie à un meilleur type d’acquisition, ce qui pourrait contribuer à révéler de nouveaux détails anatomiques non discernables à la résolution spatiale présentement utilisée par la communauté d’IRM de diffusion. Ceci pourrait aussi éventuellement contribuer à identifier de nouveaux biomarqueurs permettant de comprendre les maladies dégénératives telles que la sclérose en plaques, la maladie d’Alzheimer et la maladie de Parkinson.

The physical-layer security of a line-of-sight (LOS) free-space optical (FSO) link using orbital angular momentum (OAM) multiplexing is studied. We discuss the effect of atmospheric turbulence to OAM-multiplexed FSO channels. We numerically simulate the propagation of OAM-multiplexed beam and study the secrecy capacity. We show that, under certain conditions, the OAM multiplexing technique provides higher security over a single-mode transmission channel in terms of the total secrecy capacity and the probability of achieving a secure communication. We also study the power cost effect at the transmitter side for both fixed system power and equal channel power scenarios.

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Baigiamojo darbo tikslas – sukurti precizinių kampinių skalių formavimo įrenginį. Darbe yra išanalizuoti kampinių skalių formavimo metodai ir jų realizacijos sistemos, išskirti kampinių skalių formavimo neapibrėžties sandai, suformuoti darbo tikslai, užduotys. Yra išanalizuotos ir ištirtos optimalios įrenginio komponentės. Pasiūlyta įrenginio schema. Nustatyti rastrinių skalių originalų formavimo neapibrėžties atsiradimo dėsningumai. Išskirtos trys pagrindinės paklaidų grupės: judesio, temperatūrinės, kalibravimo. Darbe pateikiama tyrimo metodika – tyrimų eiga, tyriami mazgai ir sistemos, rezultatų apdorojimo metodika. Tyrimo rezultatai pateikti grafiškai, apdoroti statistiniais metodais, apibendrinantys rezultatai apkroksimuoti parametrinėmis funkcijomis. Darbą sudaro 9 dalys: įvadas, problemos analizė ir užduoties formulavimas, precizinių suklių tyrimai, kampo matavimo sistemos kalibravimo tikslumo tyrimas, temperatūrinių gradientų ir jų poveikio tyrimas, linijinių poslinkių matavimų tyrimai, kampinių skalių originalų konstrukcijos parinkimas ir pagrindimas, išvados, literatūros sąrašas. Darbo apimtis – 83 p. teksto be priedų, 55 iliustracijų, 35 bibliografinių šaltinių. Atskirai pridedami priedai. / Final work is dedicated for development of device for precision angular glass scales originals forming. Methods of angular scales forming and their realization have been analyzed. Distinguished angular scales forming elements of uncertainty. Work objectives and tasks have been formed. There are analyzed and researched the optimum device composition. Device scheme is proposed. Angular raster scales forming uncertainty occurrence of patterns determined. Identified three main error groups: motion, temperature and calibration. The work presents research methodology – research process, research components and systems, research data processing techniques. The results are presented graphically and processed by statistical methods, summarized results approximated by parametrical functions. Thesis consists of 9 chapters: introduction, problem analysis and formulation of the task, precision spindle research, angle measuring system accuracy research, temperature gradients and their impact research, linear displacement measurement study, angular scales original forming stand design selection and justification, conclusions, references. Thesis consist of: 83 p. text without appendixes, 55 pictures, 35 bibliographical entries. Appendixes included.

The algebra of SU(2) is ubiquitous in physics, applicable both to the atomic spin states and the polarisation states of light. The method developed by Majorana and Schwinger to represent pure, symmetric spin-states of arbitrary value as a product of spin-1/2 states is a powerful tool that allows for a great conceptual and practical simplification. Foremost, it allows the representation of a qudit on the same geometry as a qubit, i.e., the Bloch sphere. An experimental implementation of the Majorana representation in the realm of quantum optics is presented. The technique allows the projection of arbitrary quantum states from a coherent state input. It is also shown that the method can be used to synthesise arbitrary interference patterns with unit visibility, and without resorting to quantum resources. In this context, it is argued that neither the shape nor the visibility of the interference pattern is a good measure of quantumness. It is only the measurement scheme that allows for the perceived quantum behaviour. The Majorana representation also proves useful in delineating uncertainty limits of states with a particular spin value. Issues with traditional uncertainty relations involving the SU(2) operators, such as trivial bounds for certain states and non-invariance, are thereby resolved with the presented pictorial solution. / <p>QC 20170428</p>

HD 11112 is an old, Sun-like star that has a long-term radial velocity (RV) trend indicative of a massive companion on a wide orbit. Here we present direct images of the source responsible for the trend using the Magellan Adaptive Optics system. We detect the object (HD 11112B) at a separation of 2 2 (100 au) at multiple wavelengths spanning 0.6-4 mu m. and show that it is most likely a gravitationally bound cool white dwarf. Modeling its spectral energy distribution suggests that its mass is 0.9-1.1M(circle dot), which corresponds to very high eccentricity, near edge-on orbits from a. Markov chain Monte Carlo analysis of the RV and imaging data together. The total age of the white dwarf is > 2 sigma, which is discrepant with that of the primary star under most assumptions. The problem can be resolved if the white dwarf progenitor was initially a double white dwarf binary that then merged into the observed high-mass white dwarf. HD 11112B is a unique and intriguing benchmark object that can be used to calibrate atmospheric and evolutionary models of cool white dwarfs and should thus continue to be monitored by RV and direct imaging over the coming years.