40,034 research outputs found
A Comparison of Different Machine Transliteration Models
Machine transliteration is a method for automatically converting words in one
language into phonetically equivalent ones in another language. Machine
transliteration plays an important role in natural language applications such
as information retrieval and machine translation, especially for handling
proper nouns and technical terms. Four machine transliteration models --
grapheme-based transliteration model, phoneme-based transliteration model,
hybrid transliteration model, and correspondence-based transliteration model --
have been proposed by several researchers. To date, however, there has been
little research on a framework in which multiple transliteration models can
operate simultaneously. Furthermore, there has been no comparison of the four
models within the same framework and using the same data. We addressed these
problems by 1) modeling the four models within the same framework, 2) comparing
them under the same conditions, and 3) developing a way to improve machine
transliteration through this comparison. Our comparison showed that the hybrid
and correspondence-based models were the most effective and that the four
models can be used in a complementary manner to improve machine transliteration
performance
The Synthesis, Resolution and Configuration of Beta-hydroxyvaline
Synthesis, resolution, and configuration of alpha-hydroxyvalin
Optical Resolution and Configuration of Trans-2,3-epoxybutyric Acid
Optical resolution of epoxy derivative of butyric acid with brucine and configuration determination by treatment with ammoni
Role of high-spin hyperon resonances in the reaction of
The recent data taken by the CLAS Collaboration at the Thomas Jefferson
National Accelerator Facility for the reaction of
are reanalyzed within a relativistic meson-exchange model of hadronic
interactions. The present model is an extension of the one developed in an
earlier work by Nakayama, Oh, and Haberzettl [Phys. Rev. C 74, 035205 (2006)].
In particular, the role of the spin-5/2 and -7/2 hyperon resonances, which were
not included in the previous model, is investigated in the present study. It is
shown that the contribution of the hyperon having spin-7/2 and
positive parity has a key role to bring the model predictions into a fair
agreement with the measured data for the invariant mass
distribution.Comment: 8 pages, 3 figures, REVTe
Einstein Manifolds As Yang-Mills Instantons
It is well-known that Einstein gravity can be formulated as a gauge theory of
Lorentz group where spin connections play a role of gauge fields and Riemann
curvature tensors correspond to their field strengths. One can then pose an
interesting question: What is the Einstein equations from the gauge theory
point of view? Or equivalently, what is the gauge theory object corresponding
to Einstein manifolds? We show that the Einstein equations in four dimensions
are precisely self-duality equations in Yang-Mills gauge theory and so Einstein
manifolds correspond to Yang-Mills instantons in SO(4) = SU(2)_L x SU(2)_R
gauge theory. Specifically, we prove that any Einstein manifold with or without
a cosmological constant always arises as the sum of SU(2)_L instantons and
SU(2)_R anti-instantons. This result explains why an Einstein manifold must be
stable because two kinds of instantons belong to different gauge groups,
instantons in SU(2)_L and anti-instantons in SU(2)_R, and so they cannot decay
into a vacuum. We further illuminate the stability of Einstein manifolds by
showing that they carry nontrivial topological invariants.Comment: v4; 17 pages, published version in Mod. Phys. Lett.
Higgs bosons of a supersymmetric model at the Large Hadron Collider
It is found that CP symmetry may be explicitly broken in the Higgs sector of
a supersymmetric model with two extra neutral gauge bosons at the
one-loop level. The phenomenology of the model, the Higgs sector in particular,
is studied for a reasonable parameter space of the model, in the presence of
explicit CP violation at the one-loop level. At least one of the neutral Higgs
bosons of the model might be produced via the fusion process at the Large
Hadron Collider.Comment: 23 pages, 5 figures, JHE
Explicit CP violation in a MSSM with an extra
We study that a minimal supersymmetric standard model with an extra
gauge symmetry may accommodate the explicit CP violation at the one-loop level
through radiative corrections. This model is CP conserving at the tree level
and cannot realize the spontaneous CP violation for a wide parameter space at
the one-loop level. In explicit CP violation scenario, we calculate the Higgs
boson masses and the magnitude of the scalar-pseudoscalar mixings in this model
at the one-loop level by taking into account the contributions of top quarks,
bottom quarks, exotic quarks, and their superpartners. In particular, we
investigate how the exotic quarks and squarks would affect the
scalar-pseudoscalar mixings. It is observed that the size of the mixing between
the heaviest scalar and pseudoscalar Higgs bosons is changed up to 20 % by a
complex phase originated from the exotic quark sector of this model.Comment: 19 pages, 3 figure
On the sign of the pi-rho-omega coupling constant
It is shown that the relative sign between the and
coupling constants can be determined most sensitively from production
processes in collisions. Recent data on these reactions clearly favor the
sign of the coupling constant which is opposite to that
inferred from studies of the photoproduction reaction in combination with the
vector meson dominance assumption and used by many authors. Implication of this
finding in the description of other reactions is discussed.Comment: 6 pages, 4 figures, REVTeX, to be published in Phys. Lett.
- …