52 resultados para Questions of Space


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The increasing number of space debris in operating regions around the earth constitutes a real threat to space missions. The goal of the research is to establish appropriate scientific-technological conditions to prevent the destruction and/or impracticability of spacecraft in imminent collision in these regions. A definitive solution to this problem has not yet been reached with the degree of precision that the dynamics of spatial objects (vehicle and debris) requires mainly due to the fact that collisions occur in chains and fragmentation of these objects in the space environment. This fact threatens the space missions on time and with no prospects for a solution in the near future. We present an optimization process in finding the initial conditions (CIC) to collisions, considering the symmetry of the distributions of maximum relative positions between spatial objects with respect to the spherical angles. For this, we used the equations of the dynamics on the Clohessy-Witshire, representing a limit of validation that is highly computationally costly. We simulate different maximum relative positions values of the corresponding initial conditions given in terms of spherical angles. Our results showed that there are symmetries that significantly reduce operating costs, such that the search of the CIC is advantageously carried out up to 4 times the initial processing routine. Knowledge of CIC allows the propulsion system operating vehicle implement evasive maneuvers before impending collisions with space debris.

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Pós-graduação em Educação para a Ciência - FC

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This study aims to understand if intellectual work provides conditions for the emergence of psychic suffering inuniversity teachers in a public institution of higher education. Use is made of the philosophical assumptions ofhistorical materialism, work as a category of nuclear analysis of human phenomena, and also the categories ofalienated labor and intellectual work. It also refers to mental illnesses as a social production. The research subjectswere teachers with contracts of employment in exclusive dedication (RDIDP). It is used as an instrument for datacollection, a questionnaire with closed and opened questions of opinative character. Responses were categorized andanalyzed qualitatively and had not intention of giving statistical data. However, in order to better display, the samepercentage of the sample are presented, among which one third (29.6%) have some health problem after enteringuniversity. Of those, 15,5% are related to the organization of work, 5,6% to the working conditions, 2,8%concomitantly to the conditions and the organization of work. The results indicate that the organization of work in apublic university has shown itself as a space of psychic suffering, but also of alienation.

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The aim of the present study was to determine the effects of motor practice on visual judgments of apertures for wheelchair locomotion and the visual control of wheelchair locomotion in wheelchair users who had no prior experience. Sixteen young adults, divided into motor practice and control groups, visually judged varying apertures as passable or impassable under walking, pre-practice, and post-practice conditions. The motor practice group underwent additional motor practice in 10 blocks of five trials each, moving the wheelchair through different apertures. The relative perceptual boundary was determined based on judgment data and kinematic variables that were calculated from videos of the motor practice trials. The participants overestimated the space needed under the walking condition and underestimated it under the wheelchair conditions, independent of group. The accuracy of judgments improved from the pre-practice to post-practice condition in both groups. During motor practice, the participants adaptively modulated wheelchair locomotion, adjusting it to the apertures available. The present findings from a priori visual judgments of space and the continuous judgments that are necessary for wheelchair approach and passage through apertures appear to support the dissociation between processes of perception and action.

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Pós-graduação em Educação - FCT

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)