270 research outputs found

    Hierarchical progressive surveys. Multi-resolution HEALPix data structures for astronomical images, catalogues, and 3-dimensional data cubes

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    Scientific exploitation of the ever increasing volumes of astronomical data requires efficient and practical methods for data access, visualisation, and analysis. Hierarchical sky tessellation techniques enable a multi-resolution approach to organising data on angular scales from the full sky down to the individual image pixels. Aims. We aim to show that the Hierarchical progressive survey (HiPS) scheme for describing astronomical images, source catalogues, and three-dimensional data cubes is a practical solution to managing large volumes of heterogeneous data and that it enables a new level of scientific interoperability across large collections of data of these different data types. Methods. HiPS uses the HEALPix tessellation of the sphere to define a hierarchical tile and pixel structure to describe and organise astronomical data. HiPS is designed to conserve the scientific properties of the data alongside both visualisation considerations and emphasis on the ease of implementation. We describe the development of HiPS to manage a large number of diverse image surveys, as well as the extension of hierarchical image systems to cube and catalogue data. We demonstrate the interoperability of HiPS and Multi-Order Coverage (MOC) maps and highlight the HiPS mechanism to provide links to the original data. Results. Hierarchical progressive surveys have been generated by various data centres and groups for ~200 data collections including many wide area sky surveys, and archives of pointed observations. These can be accessed and visualised in Aladin, Aladin Lite, and other applications. HiPS provides a basis for further innovations in the use of hierarchical data structures to facilitate the description and statistical analysis of large astronomical data sets.Comment: 21 pages, 6 figures. Accepted for publication in Astronomy & Astrophysic

    Measurement comparison among Time-Domain, FTIR and VNA-based spectrometers in the THz frequency range

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    In this paper we present the outcome of the first international comparison in the terahertz frequency range among three different kinds of spectrometers. A Fourier-Transform infrared spectrometer, a vector network analyzer and a time-domain spectrometer have been employed for measuring the complex refractive index of three travelling standards made of selected dielectric materials in order to offer a wide enough range of parameters to be measured. The three spectrometers have been compared in terms of measurement capability and uncertainty

    El homicidio imprudente agravado por la embriaguez o el influjo de sustancias que produzcan dependencia física o psíquica

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    The first section of this article presents an overview on the problems discussed by Colombian legal scholars in relation to the crime of involuntary manslaughter aggravated by inebriation or the influence of substances that produce physical or psychological dependence, and particularly problems related to the grounds for aggravating circumstances in these events. Some opinions of the Colombian Constitutional Court are also analyzed in this section. The second part of the article aims to explain the hermeneutical difficulties that have arisen since the entry into force of Law 1696 of 2013, which modifies the regulation of involuntary manslaughter. The differences and equal treatment problems that present themselves as a result of the coexistence of sub-paragraphs 1 and 6 of article 110 of the Colombian Criminal Code are explained in this section by employing the proportionality test.La primera parte del artículo presenta un panorama general sobre los problemas discutidos en la doctrina nacional colombiana en relación con el homicidio agravado por la embriaguez o por el influjo de sustancias que producen dependencia física o psíquica , en especial los problemas relativos al fundamento de la agravación de la sanción penal para estos casos. También se analizan algunas decisiones de la Corte Constitucional en relación con el mismo tema. La segunda parte se dedica a explicar las dificultades de interpretación que surgen a partir de la entrada en vigencia de la ley 1696 de 2013, que modifica la regulación del homicidio imprudente. Allí se explican las diferencias y los problemas de igualdad de trato que se presentan a raíz de la coexistencia de los numerales 1 y 6 del art. 110 C.P., utilizando para ello el test de proporcionalidad.

    Calidad ambiental en un río urbano de llanura

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    Environmental quality in a lowland urban river. Ecological integrity or health of a river is evaluated not only by the physical chemical and biological characteristics in the fluvial channel but also by the state of the riparian systems. Attributes of the benthic communities and the riparian areas are integrated to the chemical macroindicators. The objective of this work is to evaluate the environmental quality of the Chocancharava river plain reach in the urban sector and surroundings of Río Cuarto city. Three study sites were selected: in pre-urban, urban and post-urban reaches. Sampling and field data collections were made in two different hydrological periods: winter and summer. Physical and chemical data were registered and benthos samples were taken from transects across different habitats with a Hess sampler. Multimetric indices from structural attributes such as richness, composition and tolerance/intolerance were calculated. The riparian forest quality (RFQ) was evaluated. The obtained score enabled to describe the ecological status. The physical and chemical indicators showed good water quality and the multimetric indices determined a low impaired biological quality. The application of RFQ index showed an extreme degradation of the riparian system quality. The combination of the indices determined a bad ecological status. The results of this study contribute to corroborate that the Chocancharava river, in the urban sector and its surroundings, presents environmental deterioration, and that remediation and improvement measures are necessary.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA

    Calidad ambiental en un río urbano de llanura

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    Environmental quality in a lowland urban river. Ecological integrity or health of a river is evaluated not only by the physical chemical and biological characteristics in the fluvial channel but also by the state of the riparian systems. Attributes of the benthic communities and the riparian areas are integrated to the chemical macroindicators. The objective of this work is to evaluate the environmental quality of the Chocancharava river plain reach in the urban sector and surroundings of Río Cuarto city. Three study sites were selected: in pre-urban, urban and post-urban reaches. Sampling and field data collections were made in two different hydrological periods: winter and summer. Physical and chemical data were registered and benthos samples were taken from transects across different habitats with a Hess sampler. Multimetric indices from structural attributes such as richness, composition and tolerance/intolerance were calculated. The riparian forest quality (RFQ) was evaluated. The obtained score enabled to describe the ecological status. The physical and chemical indicators showed good water quality and the multimetric indices determined a low impaired biological quality. The application of RFQ index showed an extreme degradation of the riparian system quality. The combination of the indices determined a bad ecological status. The results of this study contribute to corroborate that the Chocancharava river, in the urban sector and its surroundings, presents environmental deterioration, and that remediation and improvement measures are necessary.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA
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