2,205 research outputs found
A MILP model for an extended version of the Flexible Job Shop Problem
A MILP model for an extended version of the Flexible Job Shop Scheduling
problem is proposed. The extension allows the precedences between operations of
a job to be given by an arbitrary directed acyclic graph rather than a linear
order. The goal is the minimization of the makespan. Theoretical and practical
advantages of the proposed model are discussed. Numerical experiments show the
performance of a commercial exact solver when applied to the proposed model.
The new model is also compared with a simple extension of the model described
by \"Ozg\"uven, \"Ozbakir, and Yavuz (Mathematical models for job-shop
scheduling problems with routing and process plan flexibility, Applied
Mathematical Modelling, 34:1539--1548, 2010), using instances from the
literature and instances inspired by real data from the printing industry.Comment: 15 pages, 2 figures, 4 tables. Optimization Letters, 201
Surface gravity in dynamical spherically symmetric spacetimes
A definition of surface gravity at the apparent horizon of dynamical
spherically symmetric spacetimes is proposed. It is based on a unique foliation
by ingoing null hypersurfaces. The function parametrizing the hypersurfaces can
be interpreted as the phase of a light wave uniformly emitted by some far-away
static observer. The definition gives back the accepted value of surface
gravity in the static case by virtue of its nonlocal character. Although the
definition is motivated by the behavior of outgoing null rays, it turns out
that there is a simple connection between the generalized surface gravity, the
acceleration of any radially moving observer, and the observed frequency change
of the infalling light signal. In particular, this gives a practical and simple
method of how any geodesic observer can determine surface gravity by measuring
only the redshift of the infalling light wave. The surface gravity can be
expressed as an integral of matter field quantities along an ingoing null line,
which shows that it is a continuous function along the apparent horizon. A
formula for the area change of the apparent horizon is presented, and the
possibility of thermodynamical interpretation is discussed. Finally, concrete
expressions of surface gravity are given for a number of four-dimensional and
two-dimensional dynamical black hole solutions.Comment: 35 pages, revtex, 3 figures included using eps
Uso de imagens de radar na estimativa do ar.
O objetivo deste boletim é apresentar uma metodologia para a geração de modelo numérico de terreno (MNT), com estimativa da temperatura do ar, a partir de dados do radar SRTM. O modelo digital de elevação, gerado pela missão SRTM, forneceu as coordenadas geográficas e as altitudes necessárias para estimar-se a temperatura média do ar, utilizando-se equações de regressão múltipla. A metodologia foi eficiente na geração do mapa de temperatura média do ar do Estado de São Paulo, produto que pode ser utilizado para os mais diversos fins, tais como zoneamentos agropecuários.bitstream/item/120540/1/2249.pd
Using SAR data for soil temperature regimes classifiction in São Paulo, Brazil.
The climatic variables are used in Soil Taxonomy (Soil Survey Staff, 1999) for soil classification, because it is important to plant germination and growth, soil formation and others soil properties. Synthetic aperture radar (SAR) interferometry has been shown to be a very cost effective tool for measuring digital topography (Zyl, 2001). The data of Shuttle Radar Topography Mission (SRTM) were the results of an international mission that generate a digital elevation model (DEM) with high resolution (Souza Filho, 2003). The data were generate and provided for South America with 90m spatial resolution. The SRTM was in February, 2000 and produced the most complete terrain map of the world (Foni, Seal, 2004). A radar interferometer images a scene from two slightly different positions. In the case of a single-pass interferometer, such as SRTM, these images are acquired simultaneously. This means that one needs to separate the antenna systems in space, but always know the relative positions of the antennas in order to reconstruct the topography correctly (Zyl, 2001). The SRTM actually flew two interferometers, a C-band system, and a X-band system. The DEM generate by SRTM has a good accuracy, and besides a great advantage in the homogeneous DEM quality. Therefore, it can be used to estimate the air temperature using multiple regression analysis, based on geographic coordinates and altitude as independent variables (Pinto et al., 1972; Pedro Júnior et al., 1991; Marin et al., 2003). The Soil Taxonomy criteria to define soil temperature regimes consider soil temperature at a depth of 50cm from the soil surface, these data are rare in Brasil, and are poor to classify soil temperature regimes in brazilian territory, classifying the major portion of the country in isohyperthermic regime. The objective of this paper is present a new perspective to classify soil temperature regimes based in air temperature estimated from SRTM data, for São Paulo State
Uso de imagens de radar na estimativa da temperatura do ar.
O trabalho propõe um método para a estimativa da temperatura do ar baseado em um MDE construído a partir de dados do radar SRTM. Segundo os autores a estimativa de temperaturas medidas mensais e anuais do ar a partir de coordenadas geográficas e altitude foi pesquisada por diversos autores. Apesar do grande número de trabalhos, muitos estados brasileiros carecem de informações climatológicas de temperatura do ar, que poderiam ser geradas a partir de equações de estimativas associadas a modelos digitais de elevação (MDE)
Espacialização da pecuária de corte sul-mato-grossense.
A economia do Estado de Mato Grosso do Sul baseia-se principalmente na agricultura e pecuária, e o estado é subdivido em quatro mesorregiões: Centro-Norte, Pantanal, Sudoeste e Leste. Para espacializar a produção da pecuária bovina sul-mato-grossense, foram usados dados censitários e geocódigos municipais do IBGE e procedimentos do sistema de informação geográfica (SIG). As mesorregiões Leste e Sudoeste comportam o maior número de cabeças, da ordem de seis milhões. A mesorregião do Pantanal possui imensas áreas alagadas e favorece a exploração extensiva, e a mesorregião Centro-Norte, localizada mais próxima aos grandes mercados consumidores, têm cerca de quatro milhões de cabeças. A taxa geométrica de crescimento (TGC) do rebanho bovino de 2006 a 2011 apresenta padrão irregular, com variação de -6,86 a +7,31, -5,60 a +13,33, -2,65 a +6,65 e -5,15 a +2,45 para as regiões Pantanal, Centro-Norte, Sudoeste e Leste, respectivamente. Em termos nacionais, as projeções da TGC (2007 a 2023) para consumo e exportação são da ordem de 30% e 22,4%, respectivamente, enquanto a TGC para produção nesse mesmo período é da ordem de 18,4%. Esses números representam menos oferta interna e potencial aquecimento dos preços domésticos, contribuindo, assim, para um possível aumento da taxa de inflação no período analisado
Self-Similar Collapse of Conformally Coupled Scalar Fields
A massless scalar field minimally coupled to the gravitational field in a
simplified spherical symmetry is discussed. It is shown that, in this case, the
solution found by Roberts, describing a scalar field collapse, is in fact the
most general one. Taking that solution as departure point, a study of the
gravitational collapse for the self-similar conformal case is presented.Comment: 9 pages, accepted for publication, Classical and Quantum Gravity.
Available at http://dft.if.uerj.br/preprint/e-17.tex or at
ftp://dft.if.uerj.br/preprint/e-17.tex . Figures can be obtained on request
at [email protected]
Análise da savana e queimadas no Parque Indígena de Tumucumaque (PA) através de imagens de satélite Landsat.
The Tiriyós Savanna, inserted in the Indian Park of Tumucumaque (PA), and the occurrence of fires were analyzed using satellite images. The savanna common and permanent area in the years of 1986 and 2005 was 4.109,72 km2. The total retraction and expansion areas in the same years were 287,3 km2 and 151,8 km2, respectively. From the burnt area, 38,5% presented only one focus of fire in 9 years (from 1998 August to 2006 October); in 23,6% of the area there was fire each 4 and a half years; 25,3% each 31 months; 10,8% each 18 months and 1,8% each year. The total estimated burnt area was 4.086 km2, at maximum. The fires are considered one of the pressure factors for the advance of the amazon savannas and in the change of the coverage and usage of the earth in the Tiriyós savanna area, but the analysis of the satellite images in the years of 1986 and 2005 showed that there was a retraction of 135,5 km2 in 20 years
Comparação dos modelos digitais de elevação gerados com dados SRTM e cartas IBGE na escala 1:250.000 na região da Bacia do Camanducaia no Estado de São Paulo.
O estudo comparou os MDEs, os mapas de declividade e os mapas hipsométricos produzidos pela SRTM com aqueles gerados pelas cartas do IBGE. A área estudada integra a bacia do Camanducaia, que limita-se como Estado de São Paulo a leste e Jaguariúna a oeste, abrangendo Holambra, Jaguariúna, Santo Antônio de Posse, Pedreira, Amparo, Serra Negra, Monte Alegre do Sul, Socorro, Pinhalzinho e Pedra Bela
P18-10. Ability of HIV antigens-pulsed monocyte-derived dendritic cells to induce HIV-specific T cell response: potential use in therapeutic vaccine
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