2,882 research outputs found

    Levantamento arqueológico do Algarve: concelho de Lagoa

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    O Concelho de Lagoa, apesar da sua apreciável riqueza arqueológica, onde se destaca a estação pré-histórica de Caramujeira, descoberta em 1974 e cujos menires são hoje conhecidos do mundo científico, não se têm nele processado trabalhos de investigação que o valorizem. São excepção as pequenas escavações realizados no Ilhéu do Rosário, em meados do passado século e sob orientação de Estácio da Veiga, em Ferragudo e na Gruta de lbn Amar (Mexilhoeira), ainda quase inéditas, apesar de terem sobre elas decorrido mais de vinte e cinco anos, ou as breves campanhas verificadas na Caramujeira. De facto, os conhecimentos disponíveis sobre o seu património arqueológico resultam, sobretudo, de alguns achados ocasionais, das prospecções de Estácio da Veiga , das que um de nós procedeu nos anos setenta (M.V.G.), e das agora efectuadas e a que se somaram muitas informações dispersas, tendo em vista a elaboração do presente estudo.info:eu-repo/semantics/publishedVersio

    Modeling diameter distributions with six probability density functions in Pinus halepensis Mill. Plantations using low-density airborne laser scanning data in Aragón (northeast Spain)

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    Producción CientíficaThe diameter distributions of trees in 50 temporary sample plots (TSPs) established in Pinus halepensis Mill. stands were recovered from LiDAR metrics by using six probability density functions (PDFs): the Weibull (2P and 3P), Johnson’s SB, beta, generalized beta and gamma-2P functions. The parameters were recovered from the first and the second moments of the distributions (mean and variance, respectively) by using parameter recovery models (PRM). Linear models were used to predict both moments from LiDAR data. In recovering the functions, the location parameters of the distributions were predetermined as the minimum diameter inventoried, and scale parameters were established as the maximum diameters predicted from LiDAR metrics. The Kolmogorov–Smirnov (KS) statistic (Dn), number of acceptances by the KS test, the Cramér von Misses (W2) statistic, bias and mean square error (MSE) were used to evaluate the goodness of fits. The fits for the six recovered functions were compared with the fits to all measured data from 58 TSPs (LiDAR metrics could only be extracted from 50 of the plots). In the fitting phase, the location parameters were fixed at a suitable value determined according to the forestry literature (0.75·dmin). The linear models used to recover the two moments of the distributions and the maximum diameters determined from LiDAR data were accurate, with R2 values of 0.750, 0.724 and 0.873 for dg, dmed and dmax. Reasonable results were obtained with all six recovered functions. The goodness-of-fit statistics indicated that the beta function was the most accurate, followed by the generalized beta function. The Weibull-3P function provided the poorest fits and the Weibull-2P and Johnson’s SB also yielded poor fits to the data.Ministerio de Economía, Industria y Competitividad, Ayudas Torres Quevedo- (grant PTQ-16-08445)Fondo Europeo Agrario de Desarrollo Rural (FEADER) Programa de Desarrollo Rural de Aragón 2014-2020 - (project RF-64079

    Reproducible science: What, why, how

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    Most scientific papers are not reproducible: it is really hard, if not impossible, to understand how results are derived from data, and being able to regenerate them in the future (even by the same researchers). However, traceability and reproducibility of results are indispensable elements of highquality science, and an increasing requirement of many journals and funding sources. Reproducible studies include code able to regenerate results from the original data. This practice not only provides a perfect record of the whole analysis but also reduces the probability of errors and facilitates code reuse, thus accelerating scientific progress. But doing reproducible science also brings many benefits to the individual researcher, including saving time and effort, improved collaborations, and higher quality and impact of final publications. In this article we introduce reproducible science, why it is important, and how we can improve the reproducibility of our work. We introduce principles and tools for data management, analysis, version control, and software management that help us achieve reproducible workflows in the context of ecology.Peer Reviewe

    Ecoinformática: Nuevo grupo de trabajo de la asociación Española de ecología terrestre

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    Controlling eutrophication by means of water recirculation: an optimal control perspective

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    In this work, the artificial recirculation of water is presented and analyzed, from the perspective of the optimal control of partial differential equations, as a tool to prevent eutrophication effects in large waterbodies. A novel formulation of the environmental problem, based on the coupling of nonlinear models for hydrodynamics, water temperature and concentrations of the different species involved in the eutrophication processes, is introduced. After a complete and rigorous analysis of the existence of optimal solutions, a full numerical algorithm for their computation is proposed. Finally, some numerical results for a realistic scenario are shown, in order to prove the efficiency of our approach.Xunta de Galicia | Ref. ED431C 2019/02Agencia Estatal de Investigación | Ref. MTM2016-75140-

    AI curriculum for european high schools: an embedded intelligence approach

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    Financiado para publicación en acceso aberto: Universidade da Coruña/CISUGXunta de Galicia ; ED431G 2019/0

    Color vision in the comb frequency domain

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    In 1982, Horace Barlow considered the question of human trichromacy in the context of information theory: according to the Sampling Theorem, three types of receptors covering the visible spectrum (400- -700 nm) might be sufficient to reconstruct the color signal. Although Barlow was led to reject the direct application of the Sampling Theorem to explain color dimensionality, the theoretical framework offers a fresh point of view for analyzing the color system in conjunction with the physical characteristics of natural color signals. This review aims to illustrate that if the strict mathematical reconstruction (as implied by the Sampling Theorem) is replaced by a pragmatic approximation of color signals, then trichromacy, with its subsequent opponent-color process, could be regarded as an optimization of color constancy abilities in the spectral environment of primates. Higher dimension systems (tetrachromacy) found in other species can also serve the purpose of color constancy optimization in environments where color signals exhibit a finer spectral structure
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