6,217 research outputs found

    Finite-time blowup for a complex Ginzburg-Landau equation with linear driving

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    In this paper, we consider the complex Ginzburg--Landau equation ut=eiőł[őĒu+‚ą£u‚ą£őĪu]+ő≥uu_t = e^{i\theta} [\Delta u + |u|^\alpha u] + \gamma u on RN{\mathbb R}^N , where őĪ>0\alpha >0, ő≥‚ąąR\gamma \in \R and ‚ąíŌÄ/2<őł<ŌÄ/2-\pi /2<\theta <\pi /2. By convexity arguments we prove that, under certain conditions on őĪ,őł,ő≥\alpha ,\theta ,\gamma , a class of solutions with negative initial energy blows up in finite time

    Analytical r-mode solution with gravitational radiation reaction force

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    We present and discuss the analytical r-mode solution to the linearized hydrodynamic equations of a slowly rotating, Newtonian, barotropic, non-magnetized, perfect-fluid star in which the gravitational radiation reaction force is present.Comment: 3 pages, in Proceedings of the 5th International Workshop "New Worlds in Astroparticle Physics", Faro, Portugal, 8-10 January 200

    Inovação pedagógica para a sustentabilidade da educação aberta e em rede

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    Desenvolvemos no presente artigo uma reflex√£o e an√°lise sobre os processos que conduzem √† promo√ß√£o da inova√ß√£o pedag√≥gica nos cen√°rios emergentes para a educa√ß√£o aberta e em rede. No quadro desta an√°lise e a partir da distin√ß√£o entre media√ß√£o tecnol√≥gica e media√ß√£o pedag√≥gica, prop√Ķe-se um modelo para a mudan√ßa e inova√ß√£o baseado na media√ß√£o social e cognitiva das aprendizagens para a educa√ß√£o na sociedade digital. A media√ß√£o para a educa√ß√£o aberta situa-se para al√©m das conce√ß√Ķes de inova√ß√£o associadas √† tecnologia, para se afirmar nos desafios da aprendizagem como um processo social e cognitivo sustentado pela rede. No √Ęmbito deste enquadramento e da valoriza√ß√£o da mudan√ßa intencional na educa√ß√£o em rede, a cenariza√ß√£o da inova√ß√£o pedag√≥gica emerge do conjunto das dimens√Ķes relacionais da rede de atores que ocorrem nos ambientes de aprendizagem e conhecimento. A partir da articula√ß√£o entre os cen√°rios de inova√ß√£o no modelo pedag√≥gico e a adequa√ß√£o deste ao projeto, objetivos e pr√°ticas de aprendizagem √© proposto um conjunto de dimens√Ķes para a an√°lise da usabilidade pedag√≥gica dos ambientes de educa√ß√£o aberta e em rede na sociedade digital.We develop in this article a reflection on the processes that lead to the promotion of pedagogic innovation in emerging scenarios for open and online education. From this analysis and the distinction between technological and pedagogical mediation, we propose a model for change and innovation based on social and cognitive mediation of learning and education in the digital society. Mediation for open education lies beyond the conceptions of innovation related to technology, to assert the challenges of learning as a social and cognitive process supported by the network. Within this framework and the appreciation of the intentional change in education networking, the scenarios of pedagogical innovation emerges from all the relational dimensions of the actors that occur in the learning and knowledge network environments. From the articulation between the scenarios of innovation in pedagogical model and the suitability of this to the project, learning objectives and practices, it is proposed a set of dimensions to the analysis of the pedagogical usability of open and online education to the digital society

    Comunidades de aprendizagem e formação on-line

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