Par rapport aux détecteurs de rayons X couramment utilisés pour la cristallographie, les détecteurs à pixels hybrides apportent des avantages majeurs qui proviennent principalement de l’utilisation d'une chaîne de comptage propre à chaque pixel permettant de compter les photons individuellement et très rapidement. Les principales innovations de ces détecteurs sont les suivantes : (1) Suppression quasi totale du bruit ; (2) Obturateur électronique ultra rapide (de l'ordre de 100 ns) ; (3) Vitesse d'acquisition de 500 images par seconde. Ces avantages déjà mis à profit depuis une petite dizaine d’années sur les lignes synchrotron, sont également très prometteurs pour les diffractomètres de laboratoire. L’objet de la thèse a été de développer un diffractomètre expérimental de laboratoire équipé d’un détecteur à pixels hybrides, XPAD, et de réaliser les premières mesures de diffraction sur monocristal. Ces mesures ont permis de déterminer les corrections et calibrations du détecteur nécessaires pour les mesures sur monocristaux. Conjointement, les méthodes et techniques de traitement des images pour intégrer les intensités de diffraction ont été étudiées. L’intérêt du très faible bruit du détecteur pour l’étude de modèles de densité électronique a été démontré ; le prototype avec le détecteur XPAD a donné de meilleurs résultats que les diffractomètres usuels. Une deuxième application a consisté à utiliser les qualités de vitesse du détecteur pixel pour la mise en œuvre de mesures résolues en temps à l’échelle de la milliseconde. Des mesures sous champs électrique commuté ont permis de montrer le potentiel de ce type de détecteur dans ce domaine de recherche / Compared to X-ray detectors commonly used for crystallography, hybrid pixels detectors provide major advantages primarily due to the use of a counting system proper to each pixel allowing for very fast and individual photon counting. The main innovations of these detectors are: (1) Almost total suppression of noise ; (2) Ultra-fast electronic shutter (about 100 ns) ; (3) Acquisition rate of 500 images per second. These advantages have already been exploited over the past ten years on synchrotron beam lines and are also very promising for laboratory diffractometers. The thesis work was to realize a prototype laboratory diffractometer equipped with such a detector, XPAD, and to achieve single crystal X-ray diffraction measurements. The necessary corrections and calibrations of the detector required for diffraction measurements on single crystals were determined. The methods and image processing techniques to integrate the diffraction intensities were studied. Benefits of the very low noise of the detector for electron density models study were demonstrated; the prototype diffractometer equipped with an XPAD detector gave better results than conventional diffractometers. A second type of application was to use the pixel detector for the implementation of time-resolved diffraction measurements at millisecond timescale. Measurements under switched electric fields have shown the potential of this type of detector in this area of research

Neste estudo foi analisado o efeito de distância, velocidade, tamanhos do disco e do alvo, e massas do disco e da manopla, sobre o desempenho motor em movimentos requisitando rapidez e precisão. Para tanto, foram analisadas as características cinemáticas da tarefa de projetar um disco a um alvo com movimento de contato balístico, empunhando uma manopla. Os movimentos foram desempenhados sobre uma base plana e filmados com câmera optoeletrônica de alta freqüência. O estudo foi conduzido em seis experimentos com um grupo único de participantes. Os resultados indicaram que os modelos de controle motor que têm sido empregados para analisar a relação velocidade-precisão em tarefas mais simples não foram apropriados para explicar o comportamento da tarefa utilizada. O controle motor na tarefa demonstrou ser dinâmico e flexível, frente às diferentes restrições de movimento. As seguintes estratégias de controle foram sugeridas na explicação dos resultados: sincronização da maior velocidade e do instante de contato manopla-disco, manutenção na proporção entre as fases aceleração-desaceleração, maior inércia e menor impacto para aumentar a estabilidade de movimento, e o controle da velocidade e da precisão em dimensões independentes. A análise das ações articulares demonstrou as particularidades das estratégias utilizadas pelo sistema no movimento em função das variáveis manipuladas. Em conjunto, esta seqüência de experimentos permitiu uma compreensão mais ampla das estratégias de controle motor empregadas em movimentos com alta demanda de velocidade e de precisão / In this study it was analyzed the effect of distance, velocity, disc and target width, disc and manipulandum mass, over motor control of a rapid and accurate movement. For such, it was analyzed the kinematic characteristics of the task of launching a disc to a target using a ballistic movement, performed with a manipulandum. Movements were performed on a flat surface and filmed with a high frequency optoelectronic camera. The study was conducted through six experiments with a single group of participants. Analysis of results indicated that models of motor control that has been used to analyze speed-accuracy tradeoff in simpler tasks were not appropriate to explain the observed behavior in the task used. Motor control in the task showed to be dynamic and flexible, regarding the several constraints manipulated. The follow strategies of control were suggested to explain the results: synchronization of the peak velocity and the instant of disc-manipulandum contact, maintenance of the proportion between the acceleration-deceleration phases, greater inertia and minor impact to increase movement stability, and control of velocity and accuracy of independent dimensions. The prediction of Analysis of joint actions showed the particularities of the strategies used by the system on movement as a function of the manipulated variables. Together, this study sequence of experiments allowed for a deeper comprehension of the control strategies used in the control of rapid and accurate movements

Diploma thesis focuses on simultaneous transmission of selected photonic services by one single-mode optical fiber. The thesis deals with the problem of common transmission of multiple photonic services by one optical fiber using the wavelength division multiplex technology. Furthermore, the origin and influence of nonlinear phenomena accompanying the simultaneous transmission of photonic services are described. Except common data transmission with a bitrate of 10 Gbit/s, a common high-speed data signal transmission with a bitrate of 200 Gbit/s, accurate time transmission and high-power sensor signal are considered. During the aimultaneous transmission of selected photonic services, the measurement of the transmission parameters was performed for various variants of the simultaneous transmission arrangement. In particular, the influence of nonlinear phenomena and possible mutual interference of individual transmission channels at 50 and 100 GHz between signals was analyzed.

Following X-Ray, Ultrasound is now the most common of all the medical imaging technologies specifically in obstetrics and cardiology. Plus that the ultrasound hazards perceived to be insignificant compared with X-rays. Considering the fact that the study of cardiovascular diseases, blood flow patterns and the fetal development is essential for human life, the accuracy and proper functioning of ultrasonic systems is of great importance. Hence quality control of ultrasonic transducers is necessary. In this thesis, a system to standardize the acceptance criteria for quality control of ultrasonic transducers is described. On this ground a study on ultrasound images conducted to compare and evaluate the quality resulted from different types of transducers in different conditions, i.e. defective or functional. A clinical study was also carried out to evaluate our hypothesis in real cases at department of Cardiology and department of genecology. Results from this study show that the perception of quality is somewhat subjective and clinical studies are time-consuming. But quality factors such as the ability to accurately identify anatomical structure and functional capabilities are of great importance and help.

<p dir="ltr">Transportation and energy production industries strongly rely on improvements in gas turbine performance. The quantification of these improvements is dependent on the accuracy of the measurements performed during testing. An increase of 0.5\% in efficiency is sufficient to secure a new development program worth millions of dollars, but in the case of temperature measurements, uncertainties below 0.5 K are required, which presents a challenge. This work selects heat flux estimation and total temperature measurement uncertainties as major contributors for efficiency uncertainty.</p><ul><li>Heat flux measurements are critical to evaluate the impact on the efficiency. Additionally, thermal fatigue in turbine airfoils defines the life cycle of the engine core. This work performs an estimation of the heat transfer via a simplified numerical model that uses infrared (IR) measurements in the surface of the casing to predict the temperature of the passage wall. The model is validated with real cool-down data of the turbine to yield results within a 10\% of the actual temperature.</li><li>Total temperature measurement suffers from errors due to heat transfer effects in the probe. Two dominant sources of errors are convection and conduction between the thermocouple wires, the probe support, and the flow. These effects can be treated in two different categories: the velocity error, created by a non-isentropic reduction of the flow velocity upstream the thermocouple junction, and the thermal equilibrium effects between the junction and the probe support, involving heat transfer through the wire to the shield and the probe stem due to temperature differences between each component (the so-called \emph{conduction error}). An open jet stand is used to evaluate the effects of velocity error at various Mach numbers. The conduction error is addressed with the design and manufacturing of dual-wire thermocouple probes. The readings from two wires with different length-to-diameter ratios are used to correct for the flow total temperature. This probe yielded a recovery factor of 0.99 +/- 0.01 at Mach 0.6.</li></ul><p></p>

In-line rheological and process measurements are studied, during the primary injection phase, as a potential aid to closed loop process control for injection moulding. The feasibilities of attaining rheological and process measurements of sufficient accuracy and precision for use in process control are investigated. The influence of rheological and process measurements on product quality are investigated for semi-crystalline thermoplastic materials. A computer based process and machine parameter monitoring system is utilised to provide accurate and precise process data for analysis

No description available.

<p>In this study, we concentrate on spin-1/2 systems. A series of tools using the Liouville space method have been developed for simulating of NMR of arbitrary pulse sequences.</p> <p>We have calculated one- and two-spin symbolically, and larger systems numerically of steady states. The one-spin calculations show how SSFP converges to continuous wave NMR. A general formula for two-spin systems has been derived for the creation of double-quantum signals as a function of irradiation strength, coupling constant, and chemical shift difference. The formalism is general and can be extended to more complex spin systems.</p> <p>Estimates of transverse relaxation, R₂, are affected by frequency offset and field inhomogeneity. We find that in the presence of expected B₀ inhomogeneity, off-resonance effects can be removed from R₂ measurements, when ||omega||<= 0.5 gamma\,B₁ in Hahn echo experiments, when ||omega||<=gamma\,B₁ in CPMG experiments with specific phase variations, by fitting exact solutions of the Bloch equations given in the Lagrange form.</p> <p>Approximate solutions of CPMG experiments show the specific phase variations can significantly smooth the dependence of measured intensities on frequency offset in the range of +/- 1/2 gamma\,B₁. The effective R₂ of CPMG experiments when using a phase variation scheme can be expressed as a second-order formula with respect to the ratio of offset to pi-pulse amplitude.</p> <p>Optimization problems using the exact or approximate solution of the Bloch equations are established for designing optimal broadband universal rotation (OBUR) pulses. OBUR pulses are independent of initial magnetization and can be applied to replace any pulse of the same flip angles in a pulse sequence. We demonstrate the process to exactly and efficiently calculate the first- and second-order derivatives with respect to pulses. Using these exact derivatives, a second-order optimization method is employed to design pulses. Experiments and simulations show that OBUR pulses can provide more uniform spectra in the designed offset range and come up with advantages in CPMG experiments.</p> / Doctor of Philosophy (PhD)

The topic of this thesis project is multimedia processing, focusing on the user-sided adjustment of RGB values in video streaming using Just-In-Time (JIT) techniques and the Media Lovin’ Toolkit (MLT) framework. This is implemented in Codemill’s Accurate Player and using Web Real-Time Communication (WebRTC) as a data channel. Colour theory and RGB colour representation are discussed and technical details on the structure and usage of the MLT framework are provided. The first part of the research question aims to evaluate the feasibility of the real-time colour adjustment. This research question is answered positively by providing an implementation that can address real-world use cases. A comparison of different MLT filters is included, to select the most suitable filter for the RGB adjustment. The second part of the research question considers the comparison of video colour grading results with MLT filters that were applied on different platforms: The Accurate Player, the command line video editor Melt and the editing software KDEN Live. For this, frames of the different platforms were extracted and subtracted from each other to show differences in the colour saturations. The results reveal that the Accurate Player plays back the original video more accurately than the Melt framework. Additionally, the results lead to the assumption that KDEN Live is not using the same Melt filter as the Accurate Player to adjust the RGB values. Those significant differences in the compared frames show the complexity of the topic of colour adjustment and representation.

O objeto da tese de doutorado é a análise da relação entre a defesa da concorrência e a proteção do consumidor, duas políticas públicas que proporcionam benefícios mútuos e devem ser executadas de modo harmônico, havendo substrato normativo e teórico para incluir a preocupação com o bem-estar do consumidor como um dos objetivos da política de defesa da concorrência. No Brasil tal harmonização é uma imposição constitucional, já que a livre concorrência, a repressão ao abuso do poder econômico e a defesa do consumidor são princípios conformadores da ordem econômica. É defendida a utilização de um conceito unificado de consumidor, sendo adotada a teoria finalista, que o define como o destinatário final econômico do bem ou serviço. As duas políticas utilizam diferentes instrumentos e perspectivas na tutela do bem-estar do consumidor, o que fica claro na proteção do direito de escolha. O Código de Defesa do Consumidor oferece a isonomia como remédio para compensar a vulnerabilidade, estabelecendo regras destinadas à uma escolha consciente, sobretudo o direito à informação adequada e veraz. Já as normas de defesa da concorrência resguardam a liberdade preocupando-se em preservar a possibilidade de escolha entre mais de um fornecedor de produtos ou serviços. O exemplo mais contundente dá-se no controle de estruturas: a atuação das autoridades responsáveis pela análise dos atos de concentração é vinculada à preservação do excedente do consumidor e das condições imprescindíveis ao exercício do direito de escolha, sendo vedada a aprovação de fusões que prejudiquem o bemestar do consumidor. No âmbito repressivo a harmonização das duas políticas é intensificada com a colaboração entre as autoridades de defesa da concorrência e de proteção do consumidor para a fiscalização de condutas que configurem, ao mesmo tempo, infrações contra a ordem econômica e práticas abusivas, cuja dupla capitulação não acarreta bis in idem, pois são distintas as esferas jurídicas tuteladas, havendo assim diversidade de fundamentos. É salientada a importância das ações coletivas para reparação de danos causados aos consumidores por infrações contra a ordem econômica e defendida a adoção dos danos multiplicados e a manutenção da destinação dos valores arrecadados por multas a infrações contra a ordem econômica ao Fundo Federal de Direitos Difusos. / The thesis analyzes the relationship between the competition defense and the consumer protection, both public policies that offer mutual benefits and must be carried out in a harmonic way. So, there is a normative and theoretical substratum concerning the consumer welfare as one of the objectives of the antitrust policy. In Brazil such harmonization is imposed by the Constitution, since the free competition, the repression of the abuse of the economic power and the consumer protection are principles that pertain to the constitutional economic order. In this paper consumer is regarded as a unified concept, i.e., the economic final user of goods or services. Both policies use different instruments and perspectives for the protection of the consumer welfare, what is clear in the enforcement of the right of choice. The Consumer Defense Code refers to the isonomy as a remedy to make up for the vulnerability, establishing rules for a conscious choice, especially the right to the proper, true and accurate information. The antitrust rules are concerned with the freedom of choice and the possibilities of option from more than one supplier of products or services. The most outstanding example is related to the merger control: the antitrust authorities are required to guarantee a consumer surplus and the necessary conditions to exercise the right of choice, being totally banned the approval of mergers that may be harmful to the consumer welfare. The harmonization of both policies in the repression scope is intensified with the cooperation between antitrust and consumer protection authorities regarding to the law enforcement against practices that may represent infractions of the competition and of the consumer protection rules, as well. The thesis emphasizes the importance of class actions to repair consumer damages caused by antitrust law violations and defends the adoption of the multiplied damages and the maintenance of the allocation to the Diffuse Rights Federal Fund of amounts raised by fines collected by the Antitrust Authorities.