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726 results on '"Pizarro, J."'

201. Filosofía ambiental de campo y conservación biocultural en el Parque Etnobotánico Omora: Aproximaciones metodológicas para ampliar los modos de integrar el componente social ("S") en Sitios de Estudios Socio-Ecológicos a Largo Plazo (SESELP)

Author

ROZZI, RICARDO, primary, ANDERSON, CHRISTOPHER B, additional, PIZARRO, J. CRISTÓBAL, additional, MASSARDO, FRANCISCA, additional, MEDINA, YANET, additional, MANSILLA, ANDRÉS O, additional, KENNEDY, JAMES H, additional, OJEDA, JAIME, additional, CONTADOR, TAMARA, additional, MORALES, VERÓNICA, additional, MOSES, KELLI, additional, POOLE, ALEXANDRIA, additional, ARMESTO, JUAN J, additional, and KALIN, MARY T, additional

Published
2010
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234. Quantification of the influence of TEM operation parameters on the error of HREM image matching.

Author

Cullis, A. G., Hutchison, J. L., Pizarro, J., Guerrero, E., Galindo, P., Yañez, A., Ben, T., and Molina, S. I.

Abstract

In this paper we describe a pattern recognition system implemented to determine thickness and defocus from HRTEM simulated images. A specific task has been designed to quantify the influence of certain operation parameters of a transmission electron microscope in the global recognition error rate. This influence allows us to estimate human recognition confidence when applying pattern matching to the determination of thickness and defocus from HRTEM maps. The images considered in this task correspond to InP with the sphalerite crystalline structure and were simulated using the EMS computer software package. [ABSTRACT FROM AUTHOR]

Published
2005
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235. Strain mapping from HRTEM images.

Author

Cullis, A. G., Hutchison, J. L., Galindo, P. L., Yáñez, A., Pizarro, J., Guerrero, E., Ben, T., and Molina, S. I.

Abstract

Strain mapping is defined as a numerical image processing technique that measures the local shifts of image details around a crystal defect with respect to the ideal, defect-free, positions in the bulk. The most common algorithms for strain mapping are based on peak finding (real space) and geometric phase (Fourier space) methods. In this paper, we discuss both algorithms and propose an alternative algorithm (Peak Pairs) based on the detection of pairs of intensity maxima in the affine transformed space which exhibits good behavior at dislocations. Quantitative results are reported from experiments to determine local stresses in different types of quantum heterostructures. [ABSTRACT FROM AUTHOR]

Published
2005
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242. Effects of livestock on guanaco Lama guanicoe density, movements and habitat selection in a forest–grassland mosaic in Tierra del Fuego, Chile.

Author

Moraga, Claudio A., Funes, Martín C., Pizarro, J. Cristóbal, Briceño, Cristóbal, and Novaro, Andrés J.

Subjects
LIVESTOCK inspection, HABITAT selection, ECOLOGY, GRASSLANDS, TELEMETRY
Abstract

Locally abundant ungulates often come into conflict with human activities. After a population collapse that reached its nadir in the 1970s, the guanaco Lama guanicoe population in Tierra del Fuego, Chile, recovered and is now in conflict with sheep ranching and commercial logging. We studied the effects of livestock density and environmental factors on guanaco abundance and spatial ecology, using seasonal counts and radio-telemetry in a private protected area (Karukinka) and neighbouring ranches in a forest–grassland mosaic in Tierra del Fuego. Guanaco density was highest in low-elevation areas with more grassland cover and little snow accumulation in winter. In low-elevation areas, guanaco density decreased with increasing livestock density. Radio-tracked guanacos exhibited a partial migration pattern: two individuals migrated seasonally, selecting grasslands and avoiding forests mainly in summer, whereas six sedentary individuals used habitats according to their availability. Migratory guanacos spent the summer in Karukinka and winter on nearby ranches. High sheep densities and poor range condition on the ranches reduce key forage resources available to guanacos and may promote use of forests by guanacos, affecting forest regeneration and increasing conflict with logging. Current guanaco harvest by loggers may fail to reduce the impact of guanacos on logged-forest regeneration if guanaco spatial ecology and sheep management are not considered. Our results provide insight into the interactions among guanacos, forests and livestock ranching, and may be used to reduce conflicts and guide conservation in the Fuegian ecosystem. [ABSTRACT FROM AUTHOR]

Published
2015
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248. Experimental High Speed/Power Ratio ASIC Designs Using Residue Numbers

Author

AEROSPACE CORP EL SEGUNDO CA COMPUTER SCIENCE LAB, Simoneau, A., Pizarro, J., Parker, A., AEROSPACE CORP EL SEGUNDO CA COMPUTER SCIENCE LAB, Simoneau, A., Pizarro, J., and Parker, A.

Abstract

Residue numbers have traditionally been popular for signal processing applications and have recently received renewed interest, for a number of reasons. The inherent parallelism of the residue number system enables the throughput of a system to be increased while keeping the cost reasonable. With the advent of VLSI circuits, the increased size and complexity of parallel residue number circuits may no longer be prohibitive. A method for implementing onboard signal processing algorithms using CMOS Application Specific Integrated Circuits (ASIC) is presented in this report. This method uses residue arithmetic in a one-out-of-n representation. The representation and implementation methods provide low-power circuits that retain their high-performance capabilities. Details of the adder and multiplier circuits are given, along with an overview of the input/output conversion logic. A specific example algorithm that performs a matrix multiplication has been chosen and implemented. Test chips of the adder demonstrate that the add function performs within our design constraints. Test chips of the algorithm for a particular residue have demonstrated that the arithmetic portions of the chip functioned as expected. Some preliminary results are included at the end of this report with some caveats regarding the particular implementation that we choose.

Published
1990

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