Indoor radon measurements in six Latin American countries

Most of the natural radiation dose to man comes from radon gas and its progeny. Several countries have established national institutions and national programs in charge of the study of radon and its connection with lung cancer risk and public health. In this paper an indoor radon measurements in Latin American countries is presented. The participants in this work were from Argentina, Brazil, Ecuador, Mexico, Peru and Venezuela. Many different techniques are used in this common effort, and the indoor radon levels in specific locations in each of the participant countries are presented.

Orientação geográfica de estufas de polietileno e potenciais de água no solo no cultivo do melão rendilhado híbrido 'nero'

This study aimed to verify the effects of four different minimum soil watler potentials (-30, -40, -50 e -70 kPa) and two different plastic tunnel positions (North-South and East-West) on net melon yield. The results showed that in the East-West position the yield and fruit weight were higher than in the North-South position. The highest yields of melon crop were obtained from -30 kPa. to -40 kPa minimum soil water potential.

Orientação semi-automática de imagens CBERS usando rodovias como controle de campo

In this paper is proposed a methodology for semiautomatic CBERS image orientation using roads as ground control. It is based on an iterative strategy involving three steps. In the first step, an operator identifies on the image the ground control roads and supplies along them a few seed points, which could be sparsely and coarsely distributed. These seed points are used by the dynamic programming algorithm for extracting the ground control roads from the image. In the second step, it is established the correspondences between points describing the ground control roads and the corresponding ones extracted from the image. In the last step, the corresponding points are used to orient the CBERS image by using the DLT (Direct Linear Transformation). The two last steps are iterated until the convergence of the orientation process is verified. Experimental results showed that the proposed methodology was efficient with several test images. In all cases the orientation process converged. Moreover, the estimated orientation parameters allowed the registration of check roads with pixel accuracy or better.

Um modelo para orientação de imagens orbitais baseado em feições retas

The aim of this paper is to present a model for orientation of pushbroom sensors that allows estimating the polynomial coefficients describing the trajectory of the platform, using linear features as ground control. Considering that pushbroom image acquisition is not instantaneous, six EOP (Exterior Orientation Parameters) for each scanned line must be estimated. The sensor position and attitude parameters are modeled with a time dependent polynomial. The relationship between object and image space is established through a mathematical model based on the equivalence between the vector normal to the projection plane in the image space and to the vector normal to the rotated projection plane in the object space. The equivalence property between planes was adapted to consider the pushbroom geometry. Some experiments with simulated data corresponding to CBERS scene (China-Brazil Earth Resource Satellite) were accomplished in order to test the developed model using straight lines. Moreover, experiments with points ground with the model based on collinearity equations adapted to the pushbroom geometry were also accomplished. The obtained results showed that the proposed model can be used to estimate the EOP of pushbroom images with suitable accuracy.

Anuario estadístico de América Latina, 1979 = Statistical yearbook for Latin America, 1979

Publicado en 1980

Anuario estadístico de América Latina y el Caribe, 1985 = Statistical yearbook for Latin America and the Caribbean, 1985

Publicado en agosto de 1986

Anuario estadístico de América Latina y el Caribe, 1986 = Statistical yearbook for Latin America and the Caribbean, 1986

Publicado en junio de 1987

Anuario estadístico de América Latina y el Caribe, 1987 = Statistical yearbook for Latin America and the Caribbean, 1987

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Anuario estadístico de América Latina y el Caribe, 1988 = Statistical yearbook for Latin America and the Caribbean, 1988

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Anuario estadístico de América Latina y el Caribe, 1989 = Statistical yearbook for Latin America and the Caribbean, 1989

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Anuario Estadístico de América Latina y el Caribe 1990 = Statistical Yearbook for Latin America and the Caribbean 1990

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Anuario Estadístico de América Latina y el Caribe 1991 = Statistical Yearbook for Latin America and the Caribbean 1991

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Anuario Estadístico de América Latina y el Caribe 1992 = Statistical Yearbook for Latin America and the Caribbean 1992

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Anuario Estadístico de América Latina y el Caribe 1993 = Statistical Yearbook for Latin America and the Caribbean 1993

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Anuario Estadístico de América Latina y el Caribe 1994 = Statistical Yearbook for Latin America and the Caribbean 1994

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