Title: An analysis of a basketball player's movement during the game with special focus on the centre position Objectives: This work aims to analyse and then quantify the movement load on the pivot position and compare the differences between the number of movements of ČEZ Basketball Nymburk and Real Madrid Baloncesto in their final game. Methods: The basis of this empirical study is a quantitative research that uses the method of analysis and comparison. To obtain the data, I have analysed the most frequent movements carried out by players in the game. I have collected the number of movements per each second for four positions. Observed group are centres. Movements were described theoretically, biomechanically, technically, or by using rules. After that I have used the comparison to determine the differences, which were implemented into charts and qualified in detail. Results: Movement analysis confirmed my expectations. In comparison of the pivot of an elite foreign team with the best Czech team, I have noticed significant percentage differences. Real Madrid Baloncesto players were higher in position-specific moves, such as post-up, rebounding, boxing-out, contacts, and screens. Unlike the players of ČEZ Basketball Nymburk, who achieved significantly higher values in less significant movements...

High temperature synthesis of nanocrystals in non-polar solvents typically produces materials with narrow size distribution and high yields. However, the mechanism leading to the preservation of monodispersity on depletion of monomers is not understood, for example, in the case of iron oxide nanoparticles. In our study, it was found that oleic acid, a surfactant added to the mixture of iron precursor and solvent, gradually decomposed to release carbon monoxide at 320°C. This strong reducing gaseous product had a substantial impact on the size distribution of nanocrystals produced. The reduced forms of iron oxide catalyzed the disproportionation of carbon monoxide resulting in a graphitic carbon deposit on the surface of nanoparticles. The graphite coating inhibited further growth of particles and prevented Ostwald ripening. Graphite presence was demonstrated by Raman spectroscopy and Fourier transform infrared spectroscopy. It was found that the amount of graphite deposited on the surface of nanocrystals increased with time at 320°C. Quantitative data regarding the carbon content was obtained by thermo gravimetric analysis and energy dispersive spectrometry. The surface activity of the nanocrystals was shown to be affected by the carbon coating in applications such as arsenic removal.

[pt] Os sistemas de rastreamento são uma das tecnologias cruciais para os sistemas de realidade virtual. Eles permitem detectar continuamente a posição e orientação de marcadores ou objetos específicos que o usuário utiliza para interagir com o sistema. Uma das tecnologias mais utilizadas para implementar este tipo de sistema é o rastreamento óptico, a qual permite ao usuário ter maior liberdade em seus movimentos porque não precisa de cabos ou elementos mecânicos que possam restringir ou atrapalhar a sensação de imersão que se tenta criar na interação com ambientes de realidade virtual. Este trabalho apresenta a construção e implementação de um dispositivo de entrada, baseado em rastreamento óptico, que é utilizado para interação com aplicações de realidade virtual do tipo semi-imersivas em um ambiente desktop comum. O dispositivo tem a capacidade de recuperar seis graus de liberdade dos movimentos feitos por um conjunto de marcadores que são controlados pela mão do usuário. A partir da recuperação dos seis graus de liberdade, o dispositivo é complementado com a capacidade de emissão de eventos que permitem a interação do usuário com a aplicação. No final apresenta-se uma aplicação que demonstra a adaptação dos eventos gerados e o desempenho do dispositivo implementado. / [en] Tracking systems are a fundamental technology in virtual reality systems. They provide a continuous detection of the position and orientation of markers or specific objects that the user employs to interact with the system. One of the technologies most commonly used to implement these types of systems is the optical tracking, which allows the users to have more freedom in their movements because it does not need cables or mechanical elements that can restrict or hinder the immersion sensation that is tried to create in the interaction with virtual reality environments. This work presents the construction and implementation of an input device that is based on optical tracking that is used for interaction with semiimmersive virtual reality applications on ordinary desktop environments. This device has the capability to get the six degrees of freedom of the movements made by a set of markers that are controlled by the user hand. Based on the six degrees of freedom recovered, the device is complemented with the ability to emit events that allow the interaction of the user with the application. Finally, an application is presented for demonstrating the use of the generated events and the performance of our device.

Natürliches Verhalten findet in diversen sensorischen und motorischen Modalitäten statt, und hängt vom sensorischen Feedback ab, welches das Verhalten kontinuierlich anpasst. Um die zu Grunde liegenden neuronalen Korrelate natürlichen Verhaltens untersuchen zu können, ist die Nutzung moderner Aufnahmetechniken notwendig, die oft die Kopffixierung des Tieres erfordern. Diese Einschränkung wurde mit verschiedenen Methoden angegangen, unter anderem mit virtueller Realität in Kombination mit einem luftgelagerten Ball oder Laufradsystemen. Diese Systeme haben jedoch zahlreiche Nachteile. Wir haben das Air-Track-System entwickelt, eine neue Methode für eine leicht zu bauende und nur minimale Computerverarbeitung erfordernde Verhaltensumgebung. Der Air-Track ist ein leichtgewichtiges physisches Labyrinth, das auf einem Lufttisch schwebt und alle Eigenschaften der "echten" Welt hat, einschließlich mehrerer sensorischer Modalitäten, die eng an die motorischen Handlungen gekoppelt sind. Um dieses System zu testen, trainierten wir Mäuse in Go/No-Go- und two-alternative forced choice-Aufgaben. Mäuse wählten Arme und unterschieden. Ein Kamerasystem mit eigens entwickelter Kontrolle zeichnete die Position des Tieres auf und generierte Daten, die zur Berechnung von Reaktionszeiten in den visuellen und somatosensorischen Unterscheidungsaufgaben verwendet werden konnten. Um die Bewegung des Air-Track-Systems aufzuzeichnen, entwickelten wir ein "Pixy"-System zur Bewegungsverfolgung. Wir erweiterten die Entwicklung dann zu einer allgemeinen und automatisierten optischen Methode für die Echtzeit- ebenso wie die nachträgliche Verfolgung der Mausbewegungen, und zwar sowohl für kopffixierte als auch frei bewegliche Tiere. Das Air-Track-System und die Pixy-Bewegungsverfolgung sind zweckdienliche Einheitslösungen, die die Kombination von quantitativem natürlichen Verhalten mit nahezu jedem System zur Aufzeichnung und Manipulation der Hirnaktivität in einem Hirnforschungs-Labor ermöglichen. / Natural behavior occurs in multiple sensory and motor modalities and is dependent on sensory feedback that constantly adjusts behavior. To investigate the underlying neuronal correlates of natural behavior, it is useful to have access to state-of-the-art recording equipment that frequently requires head-fixation. This limitation has been addressed with various approaches such as virtual reality with air ball or treadmill systems. However, these systems have several disadvantages. Here we developed a novel tool, the Air-Track system, an easy to build, head-fixed behavioral environment that requires only minimal computational processing. The Air-Track is a lightweight, physical maze floating on an air table that has all the properties of the “real” world, including multiple sensory modalities tightly coupled to motor actions. To test this system, we trained mice in Go/No-Go and two-alternative forced choice tasks. A custom-controlled camera system monitored animal location, and generated data that could be used to calculate reaction times in the visual and somatosensory discrimination tasks. To track the motion of the Air Track system we developed a “Pixy” tracking system based on an off-the-shelf camera system (Pixy). We then expanded the development into a generalized and automated optical method for real-time and post-hoc tracking of mice motor behavior in both head-fixed and freely moving conditions. Air-Track and Pixy-Tracking systems are convenient “one-size-fits-all” solutions that facilitate the combination of quantitative natural behavior with virtually any system for monitoring or manipulating brain activity in a neuroscience laboratory.

Interventional magnetic resonance imaging (MRI) aims at performing minimally invasive percutaneous interventions, such as tumor ablations and biopsies, under MRI guidance. During such interventions, the acquired MR image planes are typically aligned to the surgical instrument (needle) axis and to surrounding anatomical structures of interest in order to efficiently monitor the advancement in real-time of the instrument inside the patient's body. Object tracking inside the MRI is expected to facilitate and accelerate MR-guided interventions by allowing to automatically align the image planes to the surgical instrument. In this PhD thesis, an image-based workflow is proposed and refined for automatic image plane alignment. An automatic tracking workflow was developed, performing detection and tracking of a passive marker directly in clinical real-time images. This tracking workflow is designed for fully automated image plane alignment, with minimization of tracking-dedicated time. Its main drawback is its inherent dependence on the slow clinical MRI update rate. First, the addition of motion estimation and prediction with a Kalman filter was investigated and improved the workflow tracking performance. Second, a complementary optical sensor was used for multi-sensor tracking in order to decouple the tracking update rate from the MR image acquisition rate. Performance of the workflow was evaluated with both computer simulations and experiments using an MR compatible testbed. Results show a high robustness of the multi-sensor tracking approach for dynamic image plane alignment, due to the combination of the individual strengths of each sensor.

En imagerie par résonance magnétique (IRM) interventionnelle, des interventions percutanées minimalement-invasives (biopsies, ablations de tumeurs,...) sont réalisées sous guidage IRM. Lors de l’intervention, les plans de coupe acquis sont alignés sur l’outil chirurgical et les régions anatomiques d’intérêt afin de surveiller la progression de l’outil dans le corps du patient en temps réel. Le suivi d’objets dans l’IRM facilite et accélère les interventions guidées par IRM en permettant d’aligner automatiquement les plans de coupe avec l’outil chirurgical. Dans cette thèse, un système d’alignement automatique des plans de coupe établi sur une séquence IRM clinique est développé. Celui-ci réalise automatiquement la détection et le suivi d’un marqueur passif directement dans les images IRM tout en minimisant le temps d’imagerie dédié à la détection. L’inconvénient principal de cette approche est sa dépendance au temps d’acquisition de la séquence IRM clinique utilisée. Dans un premier temps, les performances du suivi ont pu être améliorées grâce à l’estimation et la prédiction du mouvement suivi par un filtre de Kalman. Puis un capteur optique complémentaire a été ajouté pour réaliser un suivi multi-capteurs, découplant ainsi la fréquence de rafraichissement du suivi de la fréquence de rafraichissement des images IRM. La performance du système développé a été évaluée par des simulations et des expériences utilisant un banc d’essai compatible IRM. Les résultats montrent une bonne robustesse du suivi multi-capteurs pour l’alignement des plans de coupe grâce à la combinaison des qualités individuelles de chaque capteur. / Interventional magnetic resonance imaging (MRI) aims at performing minimally invasive percutaneous interventions, such as tumor ablations and biopsies, under MRI guidance. During such interventions, the acquired MR image planes are typically aligned to the surgical instrument (needle) axis and to surrounding anatomical structures of interest in order to efficiently monitor the advancement in real-time of the instrument inside the patient’s body. Object tracking inside the MRI is expected to facilitate and accelerate MR-guided interventions by allowing to automatically align the image planes to the surgical instrument. In this PhD thesis, an image-based workflow is proposed and refined for automatic image plane alignment. An automatic tracking workflow was developed, performing detection and tracking of a passive marker directly in clinical real-time images. This tracking workflow is designed for fully automated image plane alignment, with minimization of tracking-dedicated time. Its main drawback is its inherent dependence on the slow clinical MRI update rate. First, the addition of motion estimation and prediction with a Kalman filter was investigated and improved the workflow tracking performance. Second, a complementary optical sensor was used for multi-sensor tracking in order to decouple the tracking update rate from the MR image acquisition rate. Performance of the workflow was evaluated with both computer simulations and experiments using an MR compatible testbed. Results show a high robustness of the multi-sensor tracking approach for dynamic image plane alignment, due to the combination of the individual strengths of each sensor.

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