1,262 research outputs found
Morphological annotation of Korean with Directly Maintainable Resources
This article describes an exclusively resource-based method of morphological
annotation of written Korean text. Korean is an agglutinative language. Our
annotator is designed to process text before the operation of a syntactic
parser. In its present state, it annotates one-stem words only. The output is a
graph of morphemes annotated with accurate linguistic information. The
granularity of the tagset is 3 to 5 times higher than usual tagsets. A
comparison with a reference annotated corpus showed that it achieves 89% recall
without any corpus training. The language resources used by the system are
lexicons of stems, transducers of suffixes and transducers of generation of
allomorphs. All can be easily updated, which allows users to control the
evolution of the performances of the system. It has been claimed that
morphological annotation of Korean text could only be performed by a
morphological analysis module accessing a lexicon of morphemes. We show that it
can also be performed directly with a lexicon of words and without applying
morphological rules at annotation time, which speeds up annotation to 1,210
word/s. The lexicon of words is obtained from the maintainable language
resources through a fully automated compilation process
Exchange rate regimes and international business cycle transmission revisited
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žíž : A paper prepared for the conference on 'Korea and the World Economy', 21-22 July 2002, Seoul, South Korea
A noncomplementation screen for quantitative trait alleles in Saccharomyces cerevisiae
Both linkage and linkage disequilibrium mapping provide well-defined approaches to mapping quantitative trait alleles. However, alleles of small effect are particularly difficult to refine to individual genes and causative mutations. Quantitative noncomplementation provides a means of directly testing individual genes for quantitative trait alleles in a fixed genetic background. Here, we implement a genome-wide noncomplementation screen for quantitative trait alleles that affect colony color or size by using the yeast deletion collection. As proof of principle, we find a previously known allele of CYS4 that affects colony color and a novel allele of CTT1 that affects resistance to hydrogen peroxide. To screen nearly 4700 genes in nine diverse yeast strains, we developed a high-throughput robotic plating assay to quantify colony color and size. Although we found hundreds of candidate alleles, reciprocal hemizygosity analysis of a select subset revealed that many of the candidates were false positives, in part the result of background-dependent haploinsufficiency or second-site mutations within the yeast deletion collection. Our results highlight the difficulty of identifying small-effect alleles but support the use of noncomplementation as a rapid means of identifying quantitative trait alleles of large effect
Upper bound of the charge diffusion constant in holography
We investigate the upper bound of charge diffusion constant in holography.
For this purpose, we apply the conjectured upper bound proposal related to the
equilibration scales () to the
Einstein-Maxwell-Axion model. () is defined
as the collision point between the diffusive hydrodynamic mode and the first
non-hydrodynamic mode, giving rise to the upper bound of the diffusion constant
at low temperature as . We show
that the upper bound proposal also works for the charge diffusion and
(), at low , is determined by and the
scaling dimension of an infra-red operator as , as for
other diffusion constants. However, for the charge diffusion, we find that the
collision occurs at real , while it is complex for other
diffusions. In order to examine the universality of the conjectured upper
bound, we also introduce a higher derivative coupling to the
Einstein-Maxwell-Axion model. This coupling is particularly interesting since
it leads to the violation of the \textit{lower} bound of the charge diffusion
constant so the correction may also have effects on the \textit{upper} bound of
the charge diffusion. We find that the higher derivative coupling does not
affect the upper bound so that the conjectured upper bound would not be easily
violated.Comment: v1: 23 pages, 10 figures; v2: minor edits, references adde
Nucleotide sequence of the vmhA gene encoding hemolysin from Vibrio mimicus
AbstractThe structural gene (vmhA) of hemolysin from Vibrio mimicus (ATCC33653) was cloned and sequenced. The vmhA gene contains an open reading frame consisting of 2232 nucleotides which can code for a protein of 744 amino acids with a predicted molecular mass of 83 059. The similarity of amino acid sequence shows 81.6% identity with Vibrio cholerae El Tor hemolysin
Holography and magnetohydrodynamics with dynamical gauge fields
Within the framework of holography, the Einstein-Maxwell action with
Dirichlet boundary conditions corresponds to a dual conformal field theory in
presence of an external gauge field. Nevertheless, in many real-world
applications, e.g., magnetohydrodynamics, plasma physics, superconductors, etc.
dynamical gauge fields and Coulomb interactions are fundamental. In this work,
we consider bottom-up holographic models at finite magnetic field and (free)
charge density in presence of dynamical boundary gauge fields which are
introduced using mixed boundary conditions. We numerically study the spectrum
of the lowest quasi-normal modes and successfully compare the obtained results
to magnetohydrodynamics theory in dimensions. Surprisingly, as far as the
electromagnetic coupling is small enough, we find perfect agreement even in the
large magnetic field limit. Our results prove that a holographic description of
magnetohydrodynamics does not necessarily need higher-form bulk fields but can
be consistently derived using mixed boundary conditions for standard gauge
fields.Comment: 54 pages, 22 figure
Electrical spin injection and detection in an InAs quantum well
We demonstrate fully electrical detection of spin injection in InAs quantum
wells. A spin polarized current is injected from a NiFe thin film to a
two-dimensional electron gas (2DEG) made of InAs based epitaxial multi-layers.
Injected spins accumulate and diffuse out in the 2DEG, and the spins are
electrically detected by a neighboring NiFe electrode. The observed spin
diffusion length is 1.8 um at 20 K. The injected spin polarization across the
NiFe/InAs interface is 1.9% at 20 K and remains at 1.4% even at room
temperature. Our experimental results will contribute significantly to the
realization of a practical spin field effect transistor
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