6,608 research outputs found
Cross-lingual Linking on the Multilingual Web of Data (position statement)
Recently, the Semantic Web has experienced signi�cant advancements in standards and techniques, as well as in the amount of semantic information available online. Even so, mechanisms are still needed to automatically reconcile semantic information when it is expressed in di�erent natural languages, so that access to Web information across language barriers can be improved. That requires developing techniques for discovering and representing cross-lingual links on the Web of Data. In this paper we explore the different dimensions of such a problem and reflect on possible avenues of research on that topic
Pressure-induced phase transitions in AgClO4
AgClO4 has been studied under compression by x-ray diffraction and density
functional theory calculations. Experimental evidence of a structural phase
transition from the tetragonal structure of AgClO4 to an orthorhombic
barite-type structure has been found at 5.1 GPa. The transition is supported by
total-energy calculations. In addition, a second transition to a monoclinic
structure is theoretically proposed to take place beyond 17 GPa. The equation
of state of the different phases is reported as well as the calculated
Raman-active phonons and their pressure evolution. Finally, we provide a
description of all the structures of AgClO4 and discuss their relationships.
The structures are also compared with those of AgCl in order to explain the
structural sequence determined for AgClO4.Comment: 38 pages, 11 figures, 4 table
Using Cross-Lingual Explicit Semantic Analysis for Improving Ontology Translation
Semantic Web aims to allow machines to make inferences using the explicit conceptualisations contained in ontologies. By pointing to ontologies, Semantic Web-based applications are able to inter-operate and share common information easily. Nevertheless, multilingual semantic applications are still rare, owing to the fact that most online ontologies are monolingual in English. In order to solve this issue, techniques for ontology localisation and translation are needed. However, traditional machine translation is difficult to apply to ontologies, owing to the fact that ontology labels tend to be quite short in length and linguistically different from the free text paradigm. In this paper, we propose an approach to enhance machine translation of ontologies based on exploiting the well-structured concept descriptions contained in the ontology. In particular, our approach leverages the semantics contained in the ontology by using Cross Lingual Explicit Semantic Analysis (CLESA) for context-based disambiguation in phrase-based Statistical Machine Translation (SMT). The presented work is novel in the sense that application of CLESA in SMT has not been performed earlier to the best of our knowledge
Dimensional reduction of the massless limit of the linearized "New Massive Gravity"
The so called "New Massive Gravity" in consists of the
Einstein-Hilbert action (with minus sign) plus a quadratic term in curvatures
(-term). Here we perform the Kaluza-Klein dimensional reduction of the
linearized -term to . We end up with a fourth-order massive
electrodynamics in described by a rank-2 tensor. Remarkably, there
appears a local symmetry in which persists even after gauging away the
Stueckelberg fields of the dimensional reduction. It plays the role of a
gauge symmetry. Although of higher-order in derivatives, the new massive
electrodynamics is ghost free, as we show here. It is shown, via master action,
to be dual to the Maxwell-Proca theory with a scalar Stueckelberg field.Comment: 12 pages, one more reference and text slightly modified accordingl
Bath Assisted Cooling of Spins
A suitable sequence of sharp pulses applied to a spin coupled to a bosonic
bath can cool its state, i.e., increase its polarization or ground state
occupation probability. Starting from an unpolarized state of the spin in
equilibrium with the bath, one can reach very low temperatures or sizeable
polarizations within a time shorter than the decoherence time. Both the bath
and external fields are necessary for the effect which comes from the
backreaction of the spin on the bath. This method can be applied to cool at
once a disordered ensemble of spins. Since the bath is crucial for this
mechanism, the cooling limits are set by the strength of its interaction with
the spin(s).Comment: 4 pages. Accepted in PR
Fuel-rich catalytic combustion of Jet-A fuel-equivalence ratios 5.0 to 8.0
Fuel-rich catalytic combustion (E.R. greater than 5.0) is a unique technique for preheating a hydrocarbon fuel to temperatures much higher than those obtained by conventional heat exchangers. In addition to producing very reactive molecules, the process upgrades the structure of the fuel by the formation of hydrogen and smaller hydrocarbons and produces a cleaner burning fuel by removing some of the fuel carbon from the soot formation chain. With fuel-rich catalytic combustion as the first stage of a two stage combustion system, enhanced fuel properties can be utilized by both high speed engines, where time for ignition and complete combustion is limited, and engines where emission of thermal NO sub x is critical. Two-stage combustion (rich-lean) has been shown to be effective for NO sub x reduction in stationary burners where residence times are long enough to burn-up the soot formed in the first stage. Such residence times are not available in aircraft engines. Thus, the soot-free nature of the present process is critical for high speed engines. The successful application of fuel-rich catalytic combustion to Jet-A, a multicomponent fuel used in gas turbine combustors, is discusssed
Internal Space for the Noncommutative Geometry Standard Model and Strings
In this paper I discuss connections between the noncommutative geometry
approach to the standard model on one side, and the internal space coming from
strings on the other. The standard model in noncommutative geometry is
described via the spectral action. I argue that an internal noncommutative
manifold compactified at the renormalization scale, could give rise to the
almost commutative geometry required by the spectral action. I then speculate
how this could arise from the noncommutative geometry given by the vertex
operators of a string theory.Comment: 1+22 pages. More typos and misprints correcte
Incidence of grapevine leafroll associated viruses -1, -2, and -3 in Mendoza vineyards
Indexación: ScieloViticulture is important in Argentina's economy, especially in the province of Mendoza,
which is responsible for more than 75% of the crop cultivated area. In this work, we evaluated the
incidence of Grapevine leafroll-associated viruses (GLRaV) -1, -2, and -3 in Vitis vinifera clones of
cultivars Cabernet Sauvignon, Cabernet Franc, and Sauvignon Blanc, planted in different zones of
Mendoza. The selected clones were previously reported as putatively infected by GLRaV-2. All selected
samples were analyzed by DAS-ELISA for GLRaV-1,-2 and -3. GLRaV-2 was the only virus identified in
all the analyzed clones. The overall infection rates were 0.6%, 18.8% and 1.2 % for GLRaV-1, 2 and 3
respectively. For the clone Cabernet Sauvignon 337, the infection rate was very high (68.3%).http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1982-56762010000600007&nrm=is
From geometric quantization to Moyal quantization
We show how the Moyal product of phase-space functions, and the Weyl
correspondence between symbols and operator kernels, may be obtained directly
using the procedures of geometric quantization, applied to the symplectic
groupoid constructed by ``doubling'' the phase space.Comment: 7 two-column pages, RevTeX, UCR--FM--03--9
Generation of Fourier transform limited heralded single photons
In this paper we study the spectral (temporal) properties of heralded single
photon wavepackets, triggered by the detection of an idler photon in the
process of parametric downconversion. The generated single photons are studied
within the framework of the chronocyclic Wigner function, from which the single
photon spectral width and temporal duration can be computed. We derive specific
conditions on the two-photon joint spectral amplitude which result in both pure
and Fourier- transform limited heralded single photons. Likewise, we present
specific source geometries which lead to the fulfilment of these conditions and
show that one of these geometries leads, for a given pump bandwidth, to the
temporally shortest possible heralded single photon wavepackets.Comment: 10 pages, 3 figure, PHYSICAL REVIEW A 75, 02381
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