419 research outputs found

    Comparação entre espécies florestais para repovoamento.

    Get PDF
    bitstream/item/101241/1/PA-1983-Carvalho-ComparacaoEspecies.pd

    Data-Driven Analysis of Engagement in Gamified Learning Environments: A Methodology for Real-Time Measurement of MOOCs

    Get PDF
    Welfare and economic development is directly dependent on the availability of highly skilled and educated individuals in society. In the UK, higher education is accessed by a large percentage of high school graduates (50% in 2017). Still, in Brazil, a limited number of pupils leaving high schools continue their education (up to 20%). Initial pioneering efforts of universities and companies to support pupils from underprivileged backgrounds, to be able to succeed in being accepted by universities include personalised learning solutions. However, initial findings show that typical distance learning problems occur with the pupil population: isolation, demotivation, and lack of engagement. Thus, researchers and companies proposed gamification. However, gamification design is traditionally exclusively based on theory-driven approaches and usually ignore the data itself. This paper takes a different approach, presenting a large-scale study that analysed, statistically and via machine learning (deep and shallow), the first batch of students trained with a Brazilian gamified intelligent learning software (called CamaleOn), to establish, via a grassroots method based on learning analytics, how gamification elements impact on student engagement. The exercise results in a novel proposal for real-time measurement on Massive Open Online Courses (MOOCs), potentially leading to iterative improvements of student support. It also specifically analyses the engagement patterns of an underserved community

    Zeta function method and repulsive Casimir forces for an unusual pair of plates at finite temperature

    Full text link
    We apply the generalized zeta function method to compute the Casimir energy and pressure between an unusual pair of parallel plates at finite temperature, namely: a perfectly conducting plate and an infinitely permeable one. The high and low temperature limits of these quantities are discussed; relationships between high and low temperature limits are estabkished by means of a modified version of the temperature inversion symmetry.Comment: latex file 9 pages, 3 figure

    Spontaneous emission of an atom near a wedge

    Full text link
    It is a well known fact that non-trivial boundary conditions affect the interaction between atoms and the always present quantized electromagnetic field. In this paper, we focus on how the spontaneous emission rate of a given excited atom is altered when placed inside a perfectly conducting wedge. We begin by briefly presenting the formalism on which our calculations are founded, proceeding then to a long but straightforward calculation of the transition rate. We present results for a general atom but, for the sake of simplicity, we narrow them down to an effective two-level system in our numerical investigations. From these we conclude that the results are physically sound.Comment: 10 pages, version replaced to match the published on

    A importância da organização da cadeia de valor da tilápia na gestão da crise hídrica.

    Get PDF
    Introdução. Caracterização produtiva e a estiagem nos polos de piscicultura dos reservatórios de Ilha solteira, submédio e baixo São Francisco e Castanhão e Orós, no período de 2012 a 2015. Ações de Mitigação. Consequências de mercado. A importancia da caracterização climática e do Cerrado no abastecimento das grandes bacias hidrográficas brasileiras. Projeções das mudanças climáticas globais e os impactos sobre os recursos hídricos brasileiros. Considerações finais. Referências.bitstream/item/139187/1/CNPAF-2015-doc24.pd
    corecore