Title: Book of problems of kinematics of mass point Author: Jana Moltašová Department: Department of Physics Education Supervisor: RNDr. Dana Mandíková, CSc. Supervisor's e-mail address: Dana.Mandikova@mff.cuni.cz Abstract: This thesis is a follow-up to the bachelor thesis titled Book of problems of kinematics of mass point for students of Physics Education. This work is a part of wider project which aim is to create an electronic collection of problems completed with detailed solutions and structured hints. Within the frame of this work was made part of collection with forty problems, which theme is kinematics of mass point. Most of problems were chosen from already existing collections and textbooks. Each problem contains task, system of hints and resulting solutions of hints, detailed solution and answer. At the beginning of the work are given aims of the work and its structure. In the next part of work is mentioned a survey of curriculum which is instructed in lower and upper secondary school and university in brief, which relates to this theme. The next part is a survey and brief characterization of collections of problems with this theme. The fourth part of the work is devoted to the electronic collection of problems, its history, the technical elaboration of problems, there is described the...

In the presented diploma thesis we study the reconstruction of the top antitop system in proton-proton colisions with central mass energy 7 TeV de- livered by LHC accelerator at CERN to the ATLAS experiment. ALPGEN and MC@NLO generators are described as two main method of top antitop pairs simulations. We compare events simulated by generators to data from LHC. The background and selection criteria are summarized. Next we de- scribed various methods of the top antitop reconstruction. Finally the Z particle was also studied. 1

We combine precision radial velocity data from four different published works of the stars in the Leo II dwarf spheroidal galaxy. This yields a data set that spans 19 years, has 14 different epochs of observation, and contains 372 unique red giant branch stars, 196 of which have repeat observations. Using this multi-epoch data set, we constrain the binary fraction for Leo II. We generate a suite of Monte Carlo simulations that test different binary fractions using Bayesian analysis and determine that the binary fraction for Leo II ranges from 0.30(-0.10)(+0.09) to 0.34(-0.11)(+0.11), depending on the distributions of binary orbital parameters assumed. This value is smaller than what has been found for the solar neighborhood (similar to 0.4-0.6) but falls within the wide range of values that have been inferred for other dwarf spheroidals (0.14-0.69). The distribution of orbital periods has the greatest impact on the binary fraction results. If the fraction we find in Leo II is present in low-mass ultra-faints, it can artificially inflate the velocity dispersion of those systems and cause them to appear more dark matter rich than in actuality. For a galaxy with an intrinsic dispersion of 1 km s(-1) and an observational sample of 100 stars, the dispersion can be increased by a factor of 1.5-2 for Leo II-like binary fractions or by a factor of three. for binary fractions on the higher end of what has been seen in other dwarf spheroidals.

L'objectif de ma thèse est de participer à la construction d'un nouveau robot humanoïde qui peut réaliser des interactions intuitives avec l'humain à travers l'observation et l'imitation. Pour cela, j'ai conduit une série d'études expérimentales chez le jeune adulte pour caractériser les propriétés cinématiques des mouvements du bras réalisés pendant des interactions motrices et sociales, autant d'éléments qui seront les patterns de référence pour le futur robot. En se concentrant sur le comportement non-verbal, nous avons testé comment les contraintes externes et internes (difficulté, prédictibilité, temporalité) façonne la cinématique des mouvements du bras et de la main dans une simple action séquentielle de prise et de pose d'un objet (étude 1 et 2). Les résultats révèlent des modulations précoces dans la cinématique de la phase d'atteinte et de saisie, en fonction de la taille et de la stabilité du réceptacle terminal sur lequel l'objet devait être placé. Ces modulations observées dans le premier élément de la séquence sont en contradiction avec les modèles d'optimisation de trajectoire utilisés en robotique pour les séquences d'action. Ils suggèrent un couplage fort entre les paramètres moteurs dans une stratégie de planification encapsulée qui rétro-propage les contraintes contextuelles sur les éléments précoces de la séquence. Pour confirmer ces résultats, une seconde série d'étude a été conduite en utilisant des tâches cinématiques et vidéos pour montrer que les intentions motrices humaines pouvaient être lues à travers la détection de ces modulations cinématiques précoces. En utilisant un système de classification artificiel, nous avons testé si les indices de bas niveau pouvaient permettre une catégorisation des essais. Les résultats montrent qu'en absence de capacité cognitive particulière, le réseau de neurone pouvait catégoriser les intentions significativement au-dessus du niveau de la chance en observant les 500 premières millisecondes de l'action (étude 3). La troisième partie de mon travail de thèse s'est tournée vers les mesures en eye-tracking. Nous avons révélé ici que la stratégie proactive de fixations oculaires utilisée pendant l'observation de l'action était similaire à celle utilisée pendant son exécution (étude 4). De plus, les catégorisations correctes d'intentions motrices étaient caractérisées par des saccades plus précises et des fixations plus longues sur l'objet. Les mouvements oculaires sont connus pour jouer un rôle important dans les interactions sociales. Ainsi, dans une dernière expérience (étude 5), nous avons mis en place un jeu compétitif en face à face révélant des effets spécifiques du contexte social qui modifie la cinématique des mouvements d'atteinte selon le type de situations interactives. Dans le manuscrit de thèse je propose une discussion qui replace les résultats dans les modèles neuronaux et cognitifs de l'intégration sensori-mmotrice. Lorsque c'est le cas, des directions futures sont suggérées à la fois pour les modèles cognitifs de contrôle moteur et pour le développement e systèmes artificiels neuro-inspirés intégrant des capacités d'interaction sociale intuitive. / The aim of my PhD thesis was to participate in the construction of a new humanoid robot that can sustain intuitive interactions with humans through observation and imitation. As such, I conducted a series of experimental studies in young adults to better characterize the kinematic properties of those arm movements performed during motor and social interactions, elements that are the reference patterns for the to-come robot. Focusing on non-verbal behavior, we tested how external and internal constraints (difficulty, predictability, timing) shaped the kinematics of both arm and hand movements in a very simple pick and place sequential action (study 1 and 2). The results revealed early modulations in kinematics in the reach-to-grasp phase depending of the size and the stability of the target pad on which the object had to be placed. These modulations observed within the first element of the sequence were in contradiction with the current optimized trajectory models used in robotics for action sequences. They suggest in fact a strong coupling of the motor parameters within an encapsulated planning strategy that back-propagates the contextual constraints on to the early elements of the motor sequence. To confirm these findings, a second serie of studies were conducted using kinematic and video based tasks to show that human motor intentions can be read through the detection of these early kinematic modulations (study 3). Using basic artificial classification, we tested whether low-revel motor indices could afford trial categorization without the need for higher-level process such as motor imagery. results indicated that indeed without cognitive abilities the neural network could categorize the intention of an observed action within the first 500ms, significantly above chance level (study 4). The third place of my PhD work turned to eye tracking. Here, we revealed that the proactive strategy of eye-fixations used during action observation were similar to those made during executed actions. Additionally, good categorization of motor intention was characterized by more accurate saccades and longer object fixations. Eye movements are known to play an important role in social intercations. Hence, in a final experiment (study 5), we setup a face-to-face competitive game to reveal the specific effects thet the social context may play on the kinematic properties of reaching during different types of interactive situations. In the PhD mansucript, I propose a general discussion that sets these results within the current cognitive and neuronal models of sensori-motor integration. When appropriate, future directions are suggested both for cognitive models of motor control and for the development of neuro-inspired articicial systems constitued with intuitive social interaction skills.

The aim of this thesis was to determine the biomechanical adaptations made by active unilateral trans-tibial amputees when they used a prosthesis incorporating a hydraulically-damped, articulating ankle-foot device compared to non-hydraulically attached devices. Kinematic and kinetic data were recorded while participants ambulated over a flat and level surface at their customary walking speeds and at speeds they perceived to be faster and slower using the hydraulic device and their habitual foot. Use of the hydraulic device resulted in increases in self-selected walking speeds with a simultaneous reduction in intact-limb work per meter travelled. Use of the device also attenuated inappropriate fluctuations in the centre-of-pressure trajectory beneath the prosthetic foot and facilitated increased residual-knee loading-response flexion and prosthetic-limb load bearing during stance. These changes occurred despite the hydraulic device absorbing more, and returning less, energy than the participants’ habitual ankle-foot devices. The changes were present across all walking speeds but were greatest at customary walking speeds. The findings suggest that a hydraulic ankle-foot device has mechanical benefits, during overground gait, for active unilateral trans-tibial amputees compared to other attachment methods. The findings also highlight that prosthetic ankle-foot device ‘performance’ can be evaluated using surrogate measures and without modelling an ‘ankle joint’ on the prosthetic limb.

Les applications tribologiques des matériaux cellulaires en présence de liquide nécessitent une connaissance de leurs modes d’endommagement, mais elles restent peu connues à l’heure actuelle. L’étude, la compréhension et la modélisation du comportement d’un matériau composite cellulaire nécessitent une approche pluridisciplinaire due au caractère hétérogène du matériau qui reste difficilement caractérisable. Ce matériau peut être analysé suivant 3 axes bien distincts : les propriétés rhéologiques (analyses sous état de déformation complexe en compression et en cisaillement avec des rhéomètres adaptés), la morphologie des alvéoles (analyses 3D optiques et tomographiques), les propriétés tribologiques (analyse en frottement de l'interface et des particules d'usure). L’intérêt majeur de notre approche est d'aborder simultanément ces 3 axes et de comprendre leurs interactions respectives. La tomographie aux rayons X, suivie d’un traitement mathématique assisté par ordinateur, complété par l'analyse des particules d'usure a permis d'identifier les morphologies responsables des fonctions spécifiques du matériau cellulaire. Un tribo-abrasimètre innovant avec des surfaces abrasives modèles a mis en évidence l’importance des cinématiques dans l’endommagement du matériau. Des méthodes de caractérisation ont été mises au point afin de quantifier la dégradation tribologique du matériau permettant également de mesurer l’impact du vieillissement (chimique, thermique et mécanique). / Tribological applications of cellular materials in the presence of liquid require acknowledge of their modes of damage, but they remain little known at present. The study, understanding and modeling the behavior of a composite cell requires a multidisciplinary approach due to the heterogeneity of the material that is difficult to characterize. This material can be analyzed along three distinct axes: the rheological properties (analysis in complex state of deformation in compression and shear with adapted rheometer), the morphology of the cells (3D optical tomographic analysis), the tribological properties (analysis in interface friction and wear particles). The major advantage of our approach is to simultaneously address these three areas and to understand their interactions. The X-ray tomography, followed by computer-assisted mathematical treatment, supplemented by the analysis of wear particles identified morphologies responsible for specific functions of cellular material. A tribo-abrasimeter with innovative models abrasive surfaces highlighted the importance of kinematics in the damage of the material. Characterization methods have been developed to quantify the tribological degradation of the material can also measure the impact of aging(chemical, thermal and mechanical).

Using a sample of nearly half a million galaxies, intersected by over 7 million lines of sight from the Sloan Digital Sky Survey Data Release 12, we trace H alpha + [N II] emission from a galactocentric projected radius, r(p), of 5 kpc to more than 100 kpc. The emission flux surface brightness is alpha r(p) 1.9 +/- 0.4. We obtain consistent results using only the Ha or [N II] flux. We measure a stronger signal for the bluer half of the target sample than for the redder half on small scales, r(p) < 20 kpc. We obtain a 3 sigma detection of H alpha + [N II] emission in the 50-100 kpc r(p) bin. The mean emission flux within this bin is (1.10 +/- 0.35) x 10(-20) erg cm(-2) s(-1) angstrom(-1), which corresponds to 1.87 x 10(-20) erg cm(-2) s(-1) arcsec(-2) or 0.0033 Rayleigh. This detection is 34 times fainter than a previous strict limit obtained using deep narrow-band imaging. The faintness of the signal demonstrates why it has been so difficult to trace recombination radiation out to large radii around galaxies. This signal, combined with published estimates of n(H), leads us to estimate the temperature of the gas to be 12,000 K, consistent with independent empirical estimates based on metal ion absorption lines and expectations from numerical simulations.

Aims. The goal of this paper is to present complete radial-velocity data for the spectroscopically selected McCormick sample of nearby K-M dwarfs and, based on these and supplementary data, to determine the space-velocity distributions of late-type stars in the solar neighborhood. Methods. We analyzed nearly 3300 measurements of radial velocities for 1049 K-M dwarfs, that we obtained during the past decade with a CORAVEL-type instrument, with a primary emphasis on detecting and eliminating from kinematic calculations the spectroscopic binaries and binary candidates. Combining radial-velocity data with HIPPARCOS/Tycho-2 astrometry we calculated the space-velocity components and parameters of the galactic orbits in a three-component model potential for the stars in the sample, that we use for kinematical analysis and for the identification of possible candidate members of nearby stellar kinematic groups. Results. We present the catalog of our observations of radial velocities for 959 stars which are not suspected of velocity variability, along with the catalog of U, V, W velocities and Galactic orbital parameters for a total of 1088 K-M stars which are used in the present kinematic analysis. Of these, 146 stars were identified as possible candidate members of the known nearby kinematic groups and suspected subgroups. The distributions of space-velocity components, orbital eccentricities, and maximum distances from the Galactic plane are consistent with the presence of young, intermediate-age and old populations of the thin disk and a small fraction (similar to 3%) of stars with the thick disk kinematics. The kinematic structure gives evidence that the bulk of K-M type stars in the immediate solar vicinity represents a dynamically relaxed stellar population. The star MCC 869 is found to be on a retrograde Galactic orbit (V = -262 km s(-1)) of low inclination (4 degrees) and can be a member of stellar stream of some dissolved structure. The Sun's velocity with respect to the Local Standard of Rest, derived from the distributions of space-velocity components, is (U-circle dot, V-circle dot, W-circle dot) = (9.0 +/- 1.4, 13.1 +/- 0.6, 7.2 +/- 0.8) km s(-1). The radial solar motion derived via the Stromberg's relation, V-circle dot = 14.2 +/- 0.8 km s(-1), agrees within the errors with the value obtained directly from the V distribution of stars on nearly circular orbits.

Les robots industriels sont très utilisés aujourd’hui dans de nombreuses applications industrielles pour leur polyvalence et leur facilité programmation. Cependant, malgré leurs performances, ces robots ne sont pas adaptés à certains procédés de fabrication où des forces uniformes et élevées ainsi qu'une précision de positionnement appropriée sont requises. Le présent travail est axé sur la robotisation de l'une des opérations à forte charge, le soudage par friction-malaxage (FSW). Cette méthode d’assemblage s’utilise pour assembler des pièces en phase solide. Pour cette raison, une force de poussée très élevée est nécessaire pour ramollir le matériau pendant cette opération. En raison des forces élevées, la position de l'outil dévie de la trajectoire désirée. Dans ces travaux de thèse, la possibilité d'utiliser un dispositif d’assistance associé à un robot manipulateur est étudiée afin d’améliorer sa capacité de charge et sa rigidité. Dans une première partie, une modélisation géométrique, cinématique et dynamique ainsi que de déformation d’un robot industriel Kuka KR500-2MT est développée en localisant la flexibilité au niveau des articulations. La deuxième partie consiste à améliorer les performances de la robotisation du procédé FSW par différentes méthodes qui sont la modification du système de compensation de gravité, l’ajout d’une masse additionnelle sur l’outil, l’ajout d’une structure parallèle et l’utilisation de deux robots en mode coopératif. Les deux dernières solutions consistent à exercer des forces directement sur l’outillage. De cette façon, le mouvement de l'outil est principalement piloté par le robot industriel, tandis que le dispositif d’assistance (soit la structure parallèle ou le deuxième robot utilisé dans le système coopératif) assure la génération de forces de poussées très élevées. Des algorithmes d’optimisation ont été utilisés afin de minimiser les déviations de l’outil et donc réduire les défauts de soudage. Finalement, une étude de l’espace de travail est menée en utilisant le logiciel Catia. La connaissance de l'espace de travail pour les solutions proposées nous permet d’estimer les applications de soudage possibles ainsi que leur comparaison.. / Nowadays industrial robots are used in many manufacturing applications because of their versatility and easy applicability. Notwithstanding their performance these robots are not suitable for some manufacturing processes where uniform and high forces together with suitable precision of position are required. The present research is focused on the robotization of one of the high-thrust operations, the friction stir welding (FSW). This method for connecting two parts works while the connected materials are in the solid phase. For this reason a very high axial force is needed to soften the material during the welding process. Due to these high forces the position of the tool of a serial robot deviates from the desired trajectory. In this PhD work, the possibility of using a parallel structure device is investigated to improve the load capacity and stiffness of a heavy loadmanipulator robot. In a first part, the geometric, kinematic and dynamic modeling and the flexibility of an industrial robot, Kuka KR500-2MT are developed by locating flexibility at the joints. The second part is to improve the performance of the FSW process using an industrial robot. So different methods are examined: the modification of the gravity compensation system, the addition of an additional mass on the tool, the addition of a parallel structure and the use of a cooperative system. The last two solutions exert forces directly on the process tool. In this way the movement of the tool is mainly generated by the industrial serial robot, while the assistive device (either the parallel structure or the second robot used in the cooperatif system) ensures the generation of very high axial forces. Optimization algorithms are developed to minimize deviations and thus reduce welding defects. Finally, a study of the workspace is studied using Catia software. Knowledge of the system workspace with the proposed solutions allows to estimate the possible welding applications that can be achieved using these systems.

La thématique de la thèse est très vaste. Sont présentées les grandeurs cinématiques locales ou régionales qui agissent sur le corps humain. La deuxième partie de la thèse décrit les méthodes optiques, par lesquelles on peut mesurer les vibrations produites par les machines-outils sur le système humain main-bras au cours de l'activité au travail. Dans la troisième partie sont donnés les effets négatifs des vibrations qui se produisent sur le système humain main-bras pendant l'exposition aux vibrations. La quatrième partie de cette thèse contient la base théorique des techniques optiques utilisées pour mesurer les vibrations. Le chapitre cinq présente la méthodologie d'expérimentation pour mesurer les vibrations. Les résultats des mesures sont indiqués dans le sixième chapitre de la thèse. Dans le chapitre sept on présente la modélisation mécanique et mathématique du système humain main-bras avec trois degrés de liberté et le dernier chapitre contient les conclusions finales. / In the first part of the doctoral thesis are presented the local and global kinematics sizes which are acting on the human body. This is followsed with the optical methods by which we can measure the vibrations produced by the machine-tools and them action on the human hand-arm system during the work activity. In the third part are given the effects of vibrations that occur on the hand-arm system during the exposure of vibrations. The fourth part of this thesis contains the theorical basis of optical techniques used for vibrations measurement. Chapter five presents the experimental methodology of vibrations measurement in comparition betsween the two methods: classical and optical. The results of measurement are given in chapter six of the thesis. In chapter seven is given the mechanical and mathematical modeling of human hand-arm system with three degrees of freedom and the eighth chapter contains the final conclusions, the personal contributions and the future research directions.