A Fast and Accurate Nonlinear Spectral Method for Image Recognition and Registration

This article addresses the problem of two- and higher dimensional pattern matching, i.e. the identification of instances of a template within a larger signal space, which is a form of registration. Unlike traditional correlation, we aim at obtaining more selective matchings by considering more strict comparisons of gray-level intensity. In order to achieve fast matching, a nonlinear thresholded version of the fast Fourier transform is applied to a gray-level decomposition of the original 2D image. The potential of the method is substantiated with respect to real data involving the selective identification of neuronal cell bodies in gray-level images.Comment: 4 pages, 3 figure

The Redner - Ben-Avraham - Kahng cluster system

We consider a coagulation model first introduced by Redner, Ben-Avraham and Krapivsky in [Redner, Ben-Avraham, Kahng: Kinetics of 'cluster eating', J. Phys. A: Math. Gen., 20 (1987), 1231-1238], the main feature of which is that the reaction between a j-cluster and a k-cluster results in the creation of a |j-k|-cluster, and not, as in Smoluchowski's model, of a (j+k)-cluster. In this paper we prove existence and uniqueness of solutions under reasonably general conditions on the coagulation coefficients, and we also establish differenciability properties and continuous dependence of solutions. Some interesting invariance properties are also proved. Finally, we study the long-time behaviour of solutions, and also present a preliminary analysis of their scaling behaviour.Comment: 24 pages. 2 figures. Dedicated to Carlos Rocha and Luis Magalhaes on the occasion of their sixtieth birthday

The Redner - Ben-Avraham - Kahng coagulation system with constant coefficients: the finite dimensional case

We study the behaviour as $t\to\infty$ of solutions $(c_j(t))$ to the Redner--Ben-Avraham--Kahng coagulation system with positive and compactly supported initial data, rigorously proving and slightly extending results originally established in [4] by means of formal arguments.Comment: 13 pages, 1 figur

Uso sustentável da água.

A Embrapa tem priorizado estudos sobre o uso sustentável da água e do solo e sobre a recuperação de APPs, cujo objetivo é propor medidas de manejo e ações mitigadoras, visando à recuperação e à reabilitação das áreas impactadas. Estas ações, se bem executadas, podem resultar em maior controle da poluição e melhor qualidade da água e do ambiente.bitstream/item/126573/1/Uso-sustentavel-da-agua.pd

In-medium formation of quarkonium

We confront preliminary RHIC data on J/Psi production in nuclear interactions with expectations which follow in scenarios involving charm quark recombination in a region of color deconfinement. The focus is on transverse momentum and rapidity spectra of the J/Psi, which carry a memory of the spectra of the charm quarks. In such a scenario, one predicts that both spectra will be narrower than those expected without recombination. Preliminary results for the transverse momentum spectra point toward a preference for the recombination picture, while the rapidity spectra do not exhibit any narrowing within present large uncertainties. We present new calculations in the recombination model for the centrality behavior of these signals, which map out the necessary experimental precision required for a definitive test.Comment: Based on invited talk at Strangeness in Quark Matter 2006, UCLA, March 26-31, 2006. Clarifying remarks added in published journal versio

Metodologia científica para extração de DNA de amostras de sangue (aves e quelônios).

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Práticas de manejo em capoeiras de pequenas propriedades em processo de transição agroecológica na zona rural de Manaus-AM.

Práticas de manejo em capoeiras de pequenas propriedades em processo de transição agroecológica na zona rural de Manaus-AM

Variabilidade patogênica e resistência genética no patossistema milho - Colletotrichum graminicola.

Suplemento. Edição dos Resumos do XLI Congresso Brasileiro de Fitopatologia, Belo Horizonte, MG, ago. 2008