9,605 research outputs found
Long-range correlations and trends in Colombian seismic time series
We study long-range correlations and trends in time series extracted from the
data of seismic events occurred from 1973 to 2011 in a rectangular region that
contains mainly all the continental part of Colombia. The long-range
correlations are detected by the calculation of the Hurst exponents for the
time series of interevent intervals, separation distances, depth differences
and magnitude differences. By using a modification of the classical
method that has been developed to detect short-range correlations in time
series, we find the existence of persistence for all the time series considered
except for magnitude differences. We find also, by using the until the
third order, that the studied time series are not influenced by trends.
Additionally, an analysis of the Hurst exponent as a function of the number of
events in the time and the maximum window size is presented.Comment: 21 pages, 6 figures, 2 figures added, types corrected, accepted to be
published in Physica
The Odyssey Approach for Optimizing Federated SPARQL Queries
Answering queries over a federation of SPARQL endpoints requires combining
data from more than one data source. Optimizing queries in such scenarios is
particularly challenging not only because of (i) the large variety of possible
query execution plans that correctly answer the query but also because (ii)
there is only limited access to statistics about schema and instance data of
remote sources. To overcome these challenges, most federated query engines rely
on heuristics to reduce the space of possible query execution plans or on
dynamic programming strategies to produce optimal plans. Nevertheless, these
plans may still exhibit a high number of intermediate results or high execution
times because of heuristics and inaccurate cost estimations. In this paper, we
present Odyssey, an approach that uses statistics that allow for a more
accurate cost estimation for federated queries and therefore enables Odyssey to
produce better query execution plans. Our experimental results show that
Odyssey produces query execution plans that are better in terms of data
transfer and execution time than state-of-the-art optimizers. Our experiments
using the FedBench benchmark show execution time gains of at least 25 times on
average.Comment: 16 pages, 10 figure
Double Threefold Degeneracies for Active and Sterile Neutrinos
We explore the possibility that the 3 active (doublet) neutrinos have nearly
degenerate masses which are split only by the usual seesaw mechanism from 3
sterile (singlet) neutrinos in the presence of a softly broken symmetry.
We take the unconventional view that the sterile neutrinos may be light, i.e.
less than 1 keV, and discuss some very interesting and novel phenomenology,
including a connection between the LSND neutrino data and solar neutrino
oscillations.Comment: 8 pages, no figur
Estudio comparativo entre dos protocolos anestésicos para la orquidectomía en el perro : sedación y bloqueo intratesticular frente a anestesia general
En este trabajo se utilizan dos protocolos anestésicos diferentes para la realización de la orquidectomía en el perro. Todos los pacientes reciben una mezcla intravenosa de medetomidina (10 μg/kg) y buprenorfina (20 μg/kg). En el primer grupo se realiza una infiltración intratesticular con lidocaína y en el segundo se administra bolos de propofol a efecto. Las cirugías son realizadas en todos los pacientes sin complicaciones. Comparativamente ambas técnicas se muestran apropiadas y seguras para este tipo de cirugía, pero la técnica local puede ofrecer varias ventajas, como son la mejor analgesia intraoperatoria, la recuperación más rápida del paciente y el menor coste económico de la misma. La aplicación de esta técnica local puede evitar el uso de anestesia general y hacer más sencillo el protocolo anestésico para este tipo de cirugías
El Thesoro de los niños de Bernabé Soler (1615), adaptación del Thesaurus puerilis de Onofre Pou (1575)
El presente artículo analiza la adaptación española del diccionario bilingüe latín-catalán
de Onofre Pou Thesaurus puerilis (1575), traducido por Bernabé Soler con el título Thesoro
de los niños (1615). La autora plantea las principales características de la obra de Pou, disposición
del contenido, estructura de los artículos, novedad desde un punto de vista lexicográfico
y pedagógico, y estudia las principales aportaciones de la adaptación de Soler.This article analyses the Spanish adaptation of the bilingual Latin-Catalan dictionary by
Onofre Pou, Thesaurus puerilis (1575), translated by Bernabé Soler under the title Thesoro de
los niños (1615). The author expounds the essential characteristics of Pous work, the layout
of the content, the organization of the articles, innovations from a lexicographical and pedagogical
point of view, and examines the principal contributions offered by Solers adaptation
El Thesoro de los niños de Bernabé Soler (1615), adaptación del Thesaurus puerilis de Onofre Pou (1575)
El presente artículo analiza la adaptación española del diccionario bilingüe latín-catalán
de Onofre Pou Thesaurus puerilis (1575), traducido por Bernabé Soler con el título Thesoro
de los niños (1615). La autora plantea las principales características de la obra de Pou, disposición
del contenido, estructura de los artículos, novedad desde un punto de vista lexicográfico
y pedagógico, y estudia las principales aportaciones de la adaptación de Soler.This article analyses the Spanish adaptation of the bilingual Latin-Catalan dictionary by
Onofre Pou, Thesaurus puerilis (1575), translated by Bernabé Soler under the title Thesoro de
los niños (1615). The author expounds the essential characteristics of Pous work, the layout
of the content, the organization of the articles, innovations from a lexicographical and pedagogical
point of view, and examines the principal contributions offered by Solers adaptation
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