Search results for "Lanceurs"

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Optimal control and applications to orbital transfer and almost-riemannian geometry

2010

In this thesis we focus on optimal control techniques as well as geometric control techniques applied to the orbital transfer problem and to almost-Riemannian geometry. In these cases, Pontryagin’s Maximum Principle allows to analyse the extremal flow of affine control systems.In the case of a satellite with low-thrust propulsion, averaging techniques give an approximated system. Averaging is explicit in the energy minimization case and is directly related to almost-riemannian problems. The geometric analysis of such problems is generalized by the study of metrics on the two-sphere of revolution. In this way it is possible to classify the situations considering the transcendance of the solu…

[SPI.OTHER]Engineering Sciences [physics]/OtherMéthode de tirHomotopieLieux de coupure et de conjugaison[ SPI.OTHER ] Engineering Sciences [physics]/Other[SPI.OTHER] Engineering Sciences [physics]/Other[ MATH.MATH-GM ] Mathematics [math]/General Mathematics [math.GM]Géométrie presque-riemannienneMoyennation[MATH.MATH-GM] Mathematics [math]/General Mathematics [math.GM]Transfert orbitalProblèmes riemanniens en deux dimensions[MATH.MATH-GM]Mathematics [math]/General Mathematics [math.GM]Contrôle optimalNo english keywordsLanceurs
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En France, des services de renseignement sans vrais contre-pouvoirs

2021

contribution à un site web; International audience; Une nouvelle loi sur le renseignement est actuellement débattue au Parlement. À la clef, bien peu d’encadrement et une légitimation a posteriori de pratiques illégales.

renseignementdonnées personnellescybersurveillancedroitlanceurs d'alerteantiterrorismevie privé[SHS.SCIPO] Humanities and Social Sciences/Political science[SHS.SCIPO]Humanities and Social Sciences/Political science
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