Fast Community Identification by Hierarchical Growth

A new method for community identification is proposed which is founded on the analysis of successive neighborhoods, reached through hierarchical growth from a starting vertex, and on the definition of communities as a subgraph whose number of inner connections is larger than outer connections. In order to determine the precision and speed of the method, it is compared with one of the most popular community identification approaches, namely Girvan and Newman's algorithm. Although the hierarchical growth method is not as precise as Girvan and Newman's method, it is potentially faster than most community finding algorithms.Comment: 6 pages, 5 figure

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

Controle de podridões-radiculares na cultura do feijoeiro: eficácia da aplicação de fungicidas no sulco de plantio.

O controle de podridões-radiculares via tratamento de sementes tem sido errático, com históricos de sucesso e insucesso em diversas regiões produtoras de feijão. A pulverização de fungicidas no sulco de plantio, já utilizada em outras culturas, como o algodão e a batata, surge como alternativa a este tratamento padrão. Por este motivo, diversos fungicidas foram testados quanto a sua eficiência no controle de podridões radiculares via pulverização no sulco de plantio do feijoeiro.bitstream/CNPAF/19135/1/doc_118.pdfConvênio: Embrapa Arroz e Feijão e Hokko do Brasil

Compatibilidade de fungicidas e inseticidas no tratamento de sementes do feijoeiro (Phaseolus vulgaris L.) associadas ou não a polímeros: relatório técnico.

Tratamento de sementes do feijoeiro com inseticida; Revestimento de sementes do feijoeiro tratadas com inseticidas e fungicidas; Experimento I - Qualidade fisiológica e sanitária; Experimento II - Teste de campo; Experimento III - Avaliação da eficiência de controle de adultos da mosca branca, Bemisia argentifolii; Conclusão; Referências bibliográficas; Anexos..bitstream/CNPAF/19141/1/doc_125.pdfCooperação técnica: Embrapa Arroz e Feijão & Bayer S/A

Efeito da mistura de fungicidas aplicados via fungigação no controle do mofo-branco do feijoeiro comum.

Procurando otimizar a eficácia de controle, este trabalho objetivou determinar o efeito preventivo e residual de fungicidas utilizados em mistura e aplicados via fungigação para o controle do mofo-branco do feijoeiro.bitstream/CNPAF/19129/1/pqfoco62.pd

PAIRWISE VELOCITIES OF GALAXIES IN THE CFA AND SSRS2 REDSHIFT SURVEYS

(compressed version) We combine the CfA Redshift Survey (CfA2) and the Southern Sky Redshift Survey (SSRS2) to estimate the pairwise velocity dispersion of galaxies \sig12 on a scale of \sim 1 \hmpc. Both surveys are complete to an apparent magnitude limit $B(0)=15.5$. Our sample includes 12,812 galaxies distributed in a volume 1.8 \times 10^6 \hmpc3. We conclude: 1) The pairwise velocity dispersion of galaxies in the combined CfA2+SSRS2 redshift survey is \sig12=540 \kms \pm 180 \kms. Both the estimate and the variance of \sig12 significantly exceed the canonical values \sig12=340 \pm40 measured by Davis \& Peebles (1983) using CfA1. 2) We derive the uncertainty in \sig12 from the variation among subsamples with volumes on the order of $7 \times 10^5$ \hmpc3. This variation is nearly an order of magnitude larger than the formal error, 36 \kms, derived using least-squares fits to the CfA2+SSRS2 correlation function. This variation among samples is consistent with the conclusions of Mo \etal (1993) for a number of smaller surveys and with the analysis of CfA1 by Zurek \etal (1994). 3) When we remove Abell clusters with $R\ge1$ from our sample, the pairwise velocity dispersion of the remaining galaxies drops to 295 \pm 99 \kms. Thus the dominant source of variance in \sig12 is the shot noise contributed by dense virialized systems. 4) The distribution of pairwise velocities is consistent with an isotropic exponential with velocity dispersion independent of scale.Comment: 61 pages uuencoded, compressed postscript in 5 pieces. Also available in one piece at http://www.dao.nrc.ca/DAO/SCIENCE/science.htm

An embedded formulation with conforming

Use of strong discontinuities with satisfaction of compatibilit

The Power Spectrum of Galaxies in the Nearby Universe

We compute the power spectrum of galaxy density fluctuations in a recently completed redshift survey of optically-selected galaxies in the southern hemisphere (SSRS2). The amplitude and shape of the SSRS2 power spectrum are consistent with results of the Center for Astrophysics redshift survey of the northern hemisphere (CfA2), including the abrupt change of slope on a scale of 30-50Mpc/h; these results are reproducible for independent volumes of space and variations are consistent with the errors estimated from mock surveys. Taken together, the SSRS2 and CfA2 form a complete sample of 14,383 galaxies which covers one-third of the sky. The power spectrum of this larger sample continues to rise on scales up to ~ 200Mpc/h, with weak evidence for flattening on the largest scales. The SSRS2+CfA2 power spectrum and the power spectrum constraints implied by COBE are well-matched by an Omega*h ~ 0.2, Omega+lambda_0=1 CDM model with minimal biasing of optically-selected galaxies.Comment: Accepted for publication in The Astrophysical Journal Letters, Sept. 23, 1994. 10 pages uuencoded compressed postscript, including two figures. JHU-9410200

The complex channel networks of bone structure

Bone structure in mammals involves a complex network of channels (Havers and Volkmann channels) required to nourish the bone marrow cells. This work describes how three-dimensional reconstructions of such systems can be obtained and represented in terms of complex networks. Three important findings are reported: (i) the fact that the channel branching density resembles a power law implies the existence of distribution hubs; (ii) the conditional node degree density indicates a clear tendency of connection between nodes with degrees 2 and 4; and (iii) the application of the recently introduced concept of hierarchical clustering coefficient allows the identification of typical scales of channel redistribution. A series of important biological insights is drawn and discussedComment: 3 pages, 1 figure, The following article has been submitted to Applied Physics Letters. If it is published, it will be found online at http://apl.aip.org

Efeito da calagem, adubação fosfatada e potássica no estabelecimento de Leucaena leucocephala.

O objetivo do estudo foi o efeito da aplicacao, no sulco de plantio de calcario dolomitico de superfosfato simples e cloreto de potassio de Leucaena leucocephala.Resum