389 research outputs found
Equivalence between Poly\'a-Szeg\H{o} and relative capacity inequalities under rearrangement
The transformations of functions acting on sublevel sets that satisfy a
P\'olya-Szeg\H{o} inequality are characterized as those being induced by
transformations of sets that do not increase the associated capacity.Comment: 9 page
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Efficient and Robust Segmentations Based on Eikonal and Diffusion PDEs
In this paper, we present efficient and simple image segmentations based on the solution of two separate Eikonal equations, each originating from a different region. Distance functions from the interior and exterior regions are computed, and final segmentation labels are determined by a competition criterion between the distance functions. We also consider applying a diffusion partial differential equation (PDE) based method to propagate information in a manner inspired by the information propagation feature of the Eikonal equation. Experimental results are presented in a particular medical image segmentation application, and demonstrate the proposed methods
Production of Gaseous Carriers Via Biomass Gasification for Energy Purposes
AbstractIt is under development a biomass gasification plant based on a 1 MWth bubbling fluidized bed (BFB) reactor with internal recirculation. Compared to conventional BFB design, the mechanism of internal circulation of solids can give beneficial effect to the process in terms of biomass conversion efficiency into gaseous product and gas quality. A model describing the process of biomass gasification in the two reaction chambers was developed. Expected results were preliminarily validated by experimental results obtained at a bench scale facility working on the same gasification concept
Fetal nutrition : a review
Knowledge of fetal nutrient supply has greatly increased in the last decade due to the availability of fetal blood samples
obtained under relatively steady-state conditions. These studies, together with studies utilizing stable isotope methodologies,
have clarified some aspects of the supply of the major nutrients for the fetus such as glucose, amino acids and fatty acids. At the
same time, the relevance of intrauterine growth has been recognized not only for the well-being of the neonate and child, but
also for later health in adulthood. The major determinants of fetal nutrient availability are maternal nutrition and metabolism
together with placental function and metabolism. The regulation of the rate of intrauterine growth is the result of complex
interactions between genetic inheritance, endocrine environment and availability of nutrients to the fetus
Levantamento florístico da regeneração natural de uma floresta secundária, para fins de manejo, no município de Bragança-PA.
Efeito dos tratamentos silviculturais para produção diversificada em floresta secundária, com vista ao seu manejo, no Nordeste paraense.
Composição florística do estrato arbóreo de uma vegetação secundária, em área de agricultura familiar, no Nordeste paraense.
Two isoperimetric inequalities for the Sobolev constant
In this note we prove two isoperimetric inequalities for the sharp constant
in the Sobolev embedding and its associated extremal function. The first such
inequality is a variation on the classical Schwarz Lemma from complex analysis,
similar to recent inequalities of Burckel, Marshall, Minda, Poggi-Corradini,
and Ransford, while the second generalises an isoperimetric inequality for the
first eigenfunction of the Laplacian due to Payne and Rayner.Comment: 11 page
Diffeomorphism-invariant properties for quasi-linear elliptic operators
For quasi-linear elliptic equations we detect relevant properties which
remain invariant under the action of a suitable class of diffeomorphisms. This
yields a connection between existence theories for equations with degenerate
and non-degenerate coerciveness.Comment: 16 page
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