5,691 research outputs found
Biometria, grau de umidade e número de sementes/Kg da espécie Euxylophora paraensis (Pau-amarelo).
bitstream/item/49394/1/fd110001.pdf1 folder
The compound Poisson limit ruling periodic extreme behaviour of non-uniformly hyperbolic dynamics
We prove that the distributional limit of the normalised number of returns to
small neighbourhoods of periodic points of non-uniformly hyperbolic dynamical
systems is compound Poisson. The returns to small balls around a fixed point in
the phase space correspond to the occurrence of rare events, or exceedances of
high thresholds, so that there is a connection between the laws of Return Times
Statistics and Extreme Value Laws. The fact that the fixed point in the phase
space is a repelling periodic point implies that there is a tendency for the
exceedances to appear in clusters whose average sizes is given by the Extremal
Index, which depends on the expansion of the system at the periodic point.
We recall that for generic points, the exceedances, in the limit, are
singular and occur at Poisson times. However, around periodic points, the
picture is different: the respective point processes of exceedances converge to
a compound Poisson process, so instead of single exceedances, we have entire
clusters of exceedances occurring at Poisson times with a geometric
distribution ruling its multiplicity.
The systems to which our results apply include: general piecewise expanding
maps of the interval (Rychlik maps), maps with indifferent fixed points
(Manneville-Pomeau maps) and Benedicks-Carleson quadratic maps.Comment: To appear in Communications in Mathematical Physic
Germinação de sementes de Aspidosperma spruceanum Benth ex Mull. Arg. (Araracanga).
bitstream/item/50188/1/fd320001.pdf1 folder
Método do índice de qualidade na determinação do frescor de peixes.
O Método do Índice de Qualidade é um sistema de controle de qualidade do frescor do pescado e baseia-se na avaliação objetiva dos principais atributos sensoriais de cada espécie de peixe, através de um sistema de pontos de demérito. O MIQ é baseado na avaliação visual e olfativa de certos atributos do peixe, principalmente a aparência dos olhos, pele e brânquias, juntamente com o odor e textura, através de um sistema de classificação por pontos de demérito, de 0 a 3. A pontuação de todos os atributos é somada para dar uma pontuação global sensorial, o chamado Índice de Qualidade (IQ). O método permite a avaliação da qualidade do pescado em questão, a previsão da validade comercial da espécie estudada, com a vantagem de ser barato, simples, requerer pouco treinamento em relação aos outros métodos e não destruir a amostra. Sua aplicação faz da análise sensorial, tão importante para avaliação do frescor do pescado, um método objetivo, permitindo de forma confiável e rápida, a avaliação da matéria-prima, seja a bordo das embarcações, no controle da matéria-prima nas indústrias, ou nos entrepostos e em postos de venda
Método do Índice de Qualidade (MIQ) para a avaliação sensorial da qualidade do pescado.
bitstream/item/74837/1/pub-207.pd
Visser's Massive Gravity Bimetric Theory Revisited
A massive gravity theory was proposed by Visser in the late nineties. This
theory, based on a backgroung metric and on an usual
dynamical metric has the advantage of being free of ghosts
as well as discontinuities present in other massive theories proposed in the
past. In the present investigation, the equations of Visser's theory are
revisited with a particular care on the related conservation laws.\ It will be
shown that a multiplicative factor is missing in the graviton tensor originally
derived by Visser, which has no incidence on the weak field approach but
becomes important in the strong field regime when, for instance, cosmological
applications are considered. In this case, contrary to some previous claims
found in the literature, we conclude that a non-static background metric is
required in order to obtain a solution able to mimic the CDM
cosmology.Comment: 10 pages - Accepted for publication in Physical Review
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