4,374 research outputs found
LabelTranslator: A Tool to Automatically Localize an Ontology
This demo proposal briefly presents LabelTranslator, a system that suggests translations of ontology labels, with the purpose of localizing ontologies. LabelTranslator takes as input an ontology whose labels are described in a source natural language and obtains the most probable translation of each ontology label into a target natural language.Our main contribution is the automatization of this process, which reduces human efforts to localize manually the ontology
Cosmological Constant and Local Gravity
We discuss the linearization of Einstein equations in the presence of a
cosmological constant, by expanding the solution for the metric around a flat
Minkowski space-time. We demonstrate that one can find consistent solutions to
the linearized set of equations for the metric perturbations, in the Lorentz
gauge, which are not spherically symmetric, but they rather exhibit a
cylindrical symmetry. We find that the components of the gravitational field
satisfying the appropriate Poisson equations have the property of ensuring that
a scalar potential can be constructed, in which both contributions, from
ordinary matter and , are attractive. In addition, there is a
novel tensor potential, induced by the pressure density, in which the effect of
the cosmological constant is repulsive. We also linearize the Schwarzschild-de
Sitter exact solution of Einstein's equations (due to a generalization of
Birkhoff's theorem) in the domain between the two horizons. We manage to
transform it first to a gauge in which the 3-space metric is conformally flat
and, then, make an additional coordinate transformation leading to the Lorentz
gauge conditions. We compare our non-spherically symmetric solution with the
linearized Schwarzschild-de Sitter metric, when the latter is transformed to
the Lorentz gauge, and we find agreement. The resulting metric, however, does
not acquire a proper Newtonian form in terms of the unique scalar potential
that solves the corresponding Poisson equation. Nevertheless, our solution is
stable, in the sense that the physical energy density is positive.Comment: 7 pages revtex, no figures; discussion on light bending added, no
effect on conclusions, version to appear in Physical Review D
Search for new physics with neutrinos at Radioactive Ion Beam facilities
We propose applications of Radioactive Ion Beam facilities to investigate
physics beyond the Standard Model. In particular, we focus on the possible
measurement of coherent neutrino-nucleus scattering and on a search for sterile
neutrinos, by means of a low energy beta-beam with a Lorentz boost factor
. In the considered setup the collected radioactive ions are
sent inside a 4 detector. For the first application we provide the number
of events associated with neutrino-nucleus coherent scattering, when the
detector is filled in with a noble liquid. For the sterile search we consider
that the spherical detector is filled in with a liquid scintillator, and that
the neutrino detection channel is inverse-beta decay. We provide the exclusion
curves for the sterile neutrino mixing parameters, based upon the 3+1
formalism, depending upon the achievable ion intensity. Our results are
obtained both from total rates, and including spectral information with binning
in energy and in distance. The proposed experiment represents a possible
alternative to clarify the current anomalies observed in neutrino experiments.Comment: 9 pages, 6 figures. v2 - added 2 figure
Classic Liberal Philosophers and their Contributions to Democracy & Justice: Discourses on Freedom, Equality, Reason, and Law
The goal of this article is to review the ideas set forth by classic liberal philosophers which contributed to the establishment of democratic values and the institutionalization of reason as a method. The emphasis is to examine the critical ideas which led to the study of natural law and civil society, focusing on freedom, equality, reason, and law. This review will provide social science students the foundational knowledge to understand the goals of human progress as expounded by classic liberal philosophers, as well as understanding reason as inextricable to democracy and the advancement of knowledge. The ideals set forth by the classic liberal philosophers such as Locke, Montesquieu, Rousseau, Wollstonecraft, and Condorcet, have left a legacy of justice from which we can continue to progress as citizens and students
Ermakov Systems with Multiplicative Noise
Using the Euler-Maruyama numerical method, we present calculations of the
Ermakov-Lewis invariant and the dynamic, geometric, and total phases for
several cases of stochastic parametric oscillators, including the simplest case
of the stochastic harmonic oscillator. The results are compared with the
corresponding numerical noiseless cases to evaluate the effect of the noise.
Besides, the noiseless cases are analytic and their analytic solutions are
briefly presented. The Ermakov-Lewis invariant is not affected by the
multiplicative noise in the three particular examples presented in this work,
whereas there is a shift effect in the case of the phasesComment: 12 pages, 4 figures, 22 reference
Twisters and signed fundamental domains for number fields
We give a signed fundamental domain for the action on of the totally positive units of a number field of degree which we assume is not totally complex. Here and denote the number of real and complex places of and denotes the positive real numbers. The signed fundamental domain consists of -dimensional -rational cones , each equipped with a sign , with the property that the net number of intersections of the cones with any -orbit is 1. The cones and the signs are explicitly constructed from any set of fundamental totally positive units and a set of "twisters", i.e. elements of whose arguments at the complex places of are sufficiently varied. Introducing twisters gives us the right number of generators for the cones and allows us to make the turn in a controlled way around the origin at each complex embedding
Using the Unispec to Test the Difference in Reflectance of the Yellow Petals of Encelia californica, Encelia farinosa, and Spartium junceum
The reflectance spectrum of three yellow flowered species (Encelia californica, Encelia farinosa, and Spartium junceum), all grown on the coast of California, was tested to determine if reflectance among the yellow flowers was significantly different. It was hypothesized that there would be a significant difference in reflectance in the 400-700 nm wavebands for the three different species of flowers which all possess yellow petals. Using a Unispec Spectral Analysis System to obtain reflectance spectra for 12 yellow petals of three flowered species, a custom index was created in order to observe differences in the yellow color of the petals, which may account for pollinator attraction and possible natural selection based evolution (N. M. Waser et. al. 1983). The index accounted for a specific range of visible light from approximately 600-700 nm, where the largest reflectance differences occurred among the three tested species. Based on the obtained measurements of the 36 different flower reflection spectra, it was observed that the reflectance for the three different species of yellow flowers was significantly different for not only the created Mariam-Valerie Index, MVI, but also for the Normalized Difference Vegetation Index, NDVI, as well. This difference among similar species may have biological importance, as this significance may account for natural selection based evolution of the flowers which could include specific pollinator selection and increased survival of these particular plants among other yellow flowered species
New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools: II. SDSS DR7 vs UKIDSS LAS DR6, SDSS DR7 vs UKIDSS LAS DR8, SDSS DR9 vs UKIDSS LAS DR10, and SDSS DR7 vs 2MASS
We aim at developing an efficient method to search for late-type subdwarfs
(metal-depleted dwarfs with spectral types >M5) to improve the current
statistics. Our objectives are: improve our knowledge of metal-poor low-mass
dwarfs, bridge the gap between the late-M and L types, determine their surface
density, and understand the impact of metallicity on the stellar and substellar
mass function.
We carried out a search cross-matching the SDSS, 2MASS, and UKIDSS using
STILTS, Aladin, and Topcat. We considered different photometric and proper
motion criteria for our selection. We identified 29 and 71 late-type subdwarf
candidates in each cross-correlation over 8826 and 3679 square degrees,
respectively. We obtained low-resolution optical spectra for 71 of our
candidates with GTC, NOT, and VLT and retrieved spectra for 30 candidates from
the SDSS spectroscopic database. We classified 92 candidates based on 101
optical spectra using two methods: spectral indices and comparison with
templates of known subdwarfs.
We confirmed 86% and 94% of the candidates as late-type subdwarfs from the
SDSS vs 2MASS and SDSS vs UKIDSS cross-matches, respectively. These subdwarfs
have spectral types ranging between M5 and L0.5 and SDSS magnitudes in the
r=19.4-23.3 mag range. Our new late-type M discoveries include 49 subdwarfs, 25
extreme subdwarfs, six ultrasubdwarfs, one subdwarf/extreme subdwarf, and two
dwarfs/subdwarfs. We derived a surface density of late-type subdwarfs of
0.040 per square degree in the SDSS DR7 vs UKIDSS LAS DR10
cross-match. We also checked the AllWISE photometry of known and new subdwarfs
and found that mid-infrared colours of M subdwarfs do not appear to differ from
their solar-metallicity counterparts of similar spectral types. However, the
J-W2 and J-W1 colours are bluer for lower metallicity dwarfs. (abstract
strongly abridged)Comment: 28 pages, 4 Tables, 10 figures, 1 appendix. Accepted to A&A.
Photometry and spectra available in a dedicated archive on late-type
subdwarfs at http://svo2.cab.inta-csic.es/vocats/ltsa
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