DSpace Communidade:
http://www.repositorio.ufop.br/handle/123456789/551
2018-02-24T05:06:19ZAsymptotic behavior of the p-torsion functions as p goes to 1.
http://www.repositorio.ufop.br/handle/123456789/9261
Título: Asymptotic behavior of the p-torsion functions as p goes to 1.
Autor(es): Bueno, Hamilton; Ercole, Grey; Macedo, Shirley S.
Resumo: Let Ω be a Lipschitz bounded domain of RN, N ≥ 2, and let
up ∈ W1,p
0 (Ω) denote the p-torsion function of Ω, p > 1. It is observed
that the value 1 for the Cheeger constant h(Ω) is threshold with respect
to the asymptotic behavior of up, as p → 1+, in the following sense:
when h(Ω) > 1, one has limp→1+ up
L∞(Ω) = 0, and when h(Ω) < 1,
one has limp→1+ up
L∞(Ω) = ∞. In the case h(Ω) = 1, it is proved that
lim supp→1+ up
L∞(Ω) < ∞. For a radial annulus Ωa,b, with inner radius
a and outer radius b, it is proved that limp→1+ up
L∞(Ωa,b) = 0 when
h(Ωa,b) = 1.2016-01-01T00:00:00ZMetastable localization of diseases in complex networks.
http://www.repositorio.ufop.br/handle/123456789/9260
Título: Metastable localization of diseases in complex networks.
Autor(es): Ferreira, Ronan Silva; Costa, Rui A. da; Dorogovtsev, Sergey; Mendes, José Fernando Ferreira
Resumo: We describe the phenomenon of localization in the epidemic susceptible-infective-susceptible model on highly
heterogeneous networks in which strongly connected nodes (hubs) play the role of centers of localization. We
find that in this model the localized states below the epidemic threshold are metastable. The longevity and scale
of the metastable outbreaks do not show a sharp localization transition; instead there is a smooth crossover from
localized to delocalized states as we approach the epidemic threshold from below. Analyzing these long-lasting
local outbreaks for a random regular graph with a hub, we show how this localization can be detected from the
shape of the distribution of the number of infective nodes.2016-01-01T00:00:00ZVulnerability of tropical soils to heavy metals : a PLS-DA classification model for Lead.
http://www.repositorio.ufop.br/handle/123456789/9259
Título: Vulnerability of tropical soils to heavy metals : a PLS-DA classification model for Lead.
Autor(es): Soares, Liliane Catone; Binatti, Júnia de Oliveira Alves; Linhares, Lucília Alves; Egreja Filho, Fernando Barboza; Fontes, Maurício P. F.
Resumo: One of themost important components of the soil vulnerability to heavy metals is related to a situationwhere the
critical load of the soil be exceeded, causing the releasing of retained metals. Soil vulnerability to a metal is a function
mainly of the interaction forces between the metal and the soil matrix, which depends on the physical and
chemical soil characteristics. This study aims to classify the soils as vulnerable or non-vulnerable for lead as a
function of the soil characteristics using Partial Least Squares Discriminant Analysis (PLS-DA). The vulnerability
was assessed by the determination of available fraction metal (AF), after a treatmentwith Pb2+. Percent AF, evaluated
by extractionwith KNO3 solution,was used as reference only to separate the samples into two classes (vulnerable
and non-vulnerable) before the model construction. The data about soil characteristics were treated by
PLS-DA aiming to discriminate the above-mentioned classes, i.e. vulnerable and non-vulnerable. The employed
PLS-DA model was built with 20 and 10 samples for the training and test sets, respectively, and in all cases
they were properly separated. The developed methodology shows high sensitivities (rate of true positives) and
specificities (rate of true negatives) for the two classes. Finally, it can be envisaged that this approach has potential
to be applied in classification of the soil vulnerability to lead, just based on soil characteristics.2017-01-01T00:00:00ZThe lack of polynomial stability to mixtures with frictional dissipation.
http://www.repositorio.ufop.br/handle/123456789/9258
Título: The lack of polynomial stability to mixtures with frictional dissipation.
Autor(es): Puma, Francis Felix Cordova; Rivera, Jaime Edilberto Munoz
Resumo: We consider the system modeling a mixture of nmaterials with frictional damping. We show that the corresponding semigroup is exponentially stable if and only if the imaginary axis is contained in the resolvent set of the infinitesimal generator. In particular this implies the lack of polynomial stability to the corresponding semigroup.2017-01-01T00:00:00Z