947 research outputs found
Found in Translation: International Residentsâ Use of Setagaya Wardâs Online Multilingual Information
The importance of e-governance in Japan has grown parallel with the need for municipalities to provide multilingual services and translation for newcomer immigrants. Few studies have examined the content of official translated online materials in the context of immigrantsâ actual experiences using such materials. The present study seeks to discover how international residents of Setagaya Ward in Tokyo access and navigate the foreign language information on the wardâs official website, in particular looking at issues of comprehension of both human and machine-translated content. Results of a survey of self-selected respondents (nïŒ52) indicate that such content is viewed as important and useful by international residents, though difficulties in locating and comprehending needed information were common. Implications of these results for official translation policy are considered in the context of notions of domestic internationalization and multicultural coexistence
The Boundary-value Problem in Domains with Very Rapidly Oscillating Boundary
AbstractWe study the asymptotic behavior of the solution to boundary-value problem for the second order elliptic equation in the bounded domain ΩΔâRnwith a very rapidly oscillating locally periodic boundary. We assume that the Fourier boundary condition involving a small positive parameter Δ is posed on the oscillating part of the boundary and that the (nâ1)-dimensional volume of this part goes to infinity as Δâ0. Under proper normalization conditions that homogenized problem is found and the estimates of the residual are obtained. Also, we construct an additional term of the asymptotics to improve the estimates of the residual. It is shown that the limiting problem can involve Dirichlet, Fourier or Neumann boundary conditions depending on the structure of the coefficient of the original problem
Nonexistence of marginally trapped surfaces and geons in 2+1 gravity
We use existence results for Jang's equation and marginally outer trapped
surfaces (MOTSs) in 2+1 gravity to obtain nonexistence of geons in 2+1 gravity.
In particular, our results show that any 2+1 initial data set, which obeys the
dominant energy condition with cosmological constant \Lambda \geq 0 and which
satisfies a mild asymptotic condition, must have trivial topology. Moreover,
any data set obeying these conditions cannot contain a MOTS. The asymptotic
condition involves a cutoff at a finite boundary at which a null mean convexity
condition is assumed to hold; this null mean convexity condition is satisfied
by all the standard asymptotic boundary conditions. The results presented here
strengthen various aspects of previous related results in the literature. These
results not only have implications for classical 2+1 gravity but also apply to
quantum 2+1 gravity when formulated using Witten's solution space quantization.Comment: v3: Elements from the original two proofs of the main result have
been combined to give a single proof, thereby circumventing an issue with the
second proof associated with potential blow-ups of solutions to Jang's
equation. To appear in Commun. Math. Phy
Relativistic Stellar Pulsations With Near-Zone Boundary Conditions
A new method is presented here for evaluating approximately the pulsation
modes of relativistic stellar models. This approximation relies on the fact
that gravitational radiation influences these modes only on timescales that are
much longer than the basic hydrodynamic timescale of the system. This makes it
possible to impose the boundary conditions on the gravitational potentials at
the surface of the star rather than in the asymptotic wave zone of the
gravitational field. This approximation is tested here by predicting the
frequencies of the outgoing non-radial hydrodynamic modes of non-rotating
stars. The real parts of the frequencies are determined with an accuracy that
is better than our knowledge of the exact frequencies (about 0.01%) except in
the most relativistic models where it decreases to about 0.1%. The imaginary
parts of the frequencies are determined with an accuracy of approximately M/R,
where M is the mass and R is the radius of the star in question.Comment: 10 pages (REVTeX 3.1), 5 figs., 1 table, fixed minor typos, published
in Phys. Rev. D 56, 2118 (1997
A lower bound for nodal count on discrete and metric graphs
According to a well-know theorem by Sturm, a vibrating string is divided into
exactly N nodal intervals by zeros of its N-th eigenfunction. Courant showed
that one half of Sturm's theorem for the strings applies to the theory of
membranes: N-th eigenfunction cannot have more than N domains. He also gave an
example of a eigenfunction high in the spectrum with a minimal number of nodal
domains, thus excluding the existence of a non-trivial lower bound. An analogue
of Sturm's result for discretizations of the interval was discussed by
Gantmacher and Krein. The discretization of an interval is a graph of a simple
form, a chain-graph. But what can be said about more complicated graphs? It has
been known since the early 90s that the nodal count for a generic eigenfunction
of the Schrodinger operator on quantum trees (where each edge is identified
with an interval of the real line and some matching conditions are enforced on
the vertices) is exact too: zeros of the N-th eigenfunction divide the tree
into exactly N subtrees. We discuss two extensions of this result in two
directions. One deals with the same continuous Schrodinger operator but on
general graphs (i.e. non-trees) and another deals with discrete Schrodinger
operator on combinatorial graphs (both trees and non-trees). The result that we
derive applies to both types of graphs: the number of nodal domains of the N-th
eigenfunction is bounded below by N-L, where L is the number of links that
distinguish the graph from a tree (defined as the dimension of the cycle space
or the rank of the fundamental group of the graph). We also show that if it the
genericity condition is dropped, the nodal count can fall arbitrarily far below
the number of the corresponding eigenfunction.Comment: 15 pages, 4 figures; Minor corrections: added 2 important reference
Second-order rotational effects on the r-modes of neutron stars
Techniques are developed here for evaluating the r-modes of rotating neutron
stars through second order in the angular velocity of the star. Second-order
corrections to the frequencies and eigenfunctions for these modes are evaluated
for neutron star models. The second-order eigenfunctions for these modes are
determined here by solving an unusual inhomogeneous hyperbolic boundary-value
problem. The numerical techniques developed to solve this unusual problem are
somewhat non-standard and may well be of interest beyond the particular
application here. The bulk-viscosity coupling to the r-modes, which appears
first at second order, is evaluated. The bulk-viscosity timescales are found
here to be longer than previous estimates for normal neutron stars, but shorter
than previous estimates for strange stars. These new timescales do not
substantially affect the current picture of the gravitational radiation driven
instability of the r-modes either for neutron stars or for strange stars.Comment: 13 pages, 5 figures, revte
High-speed metamagnetic resistive switching of FeRh through Joule heating
Due to its proximity to room temperature and demonstrated high degree of
temperature tunability, the metamagnetic ordering transition in FeRh is
attractive for novel high-performance computing devices seeking to use
magnetism as the state variable. We demonstrate electrical control of the
transition via Joule heating in FeRh wires. Finite element simulations based on
abrupt state transition within each domain result in a globally smooth
transition that agrees with the experimental findings and provides insight into
the thermodynamics involved. We measure a 150 K decrease in transition
temperature with currents up to 60 mA, limited only by the dimensions of the
device. The sizeable shift in transition temperature scales with current
density and wire length, suggesting the absolute resistance and heat
dissipation of the substrate are also important. The FeRh phase change is
evaluated by pulsed I-V using a variety of bias conditions. We demonstrate high
speed (~ ns) memristor-like behavior and report device performance parameters
such as switching speed and power consumption that compare favorably with
state-of-the-art phase change memristive technologies.Comment: 35 pages, 9 figure
Estimates of unresolved point sources contribution to WMAP 5
We present an alternative estimate of the unresolved point source
contribution to the WMAP temperature power spectrum based on current knowledge
of sources from radio surveys in the 1.4-90 GHz range. We implement a
stochastic extrapolation of radio point sources in the NRAO-VLA Sky Survey
(NVSS) catalog, from the original 1.4 GHz to the ~ 100 GHz frequency range
relevant for CMB experiments. With a bootstrap approach, we generate an
ensemble of realizations that provides the probability distribution for the
flux of each NVSS source at the final frequency. The predicted source counts
agree with WMAP results for S > 1 Jy and the corresponding sky maps correlate
with WMAP observed maps in Q-, V- and W- bands, for sources with flux S > 0.2
Jy. The low-frequency radio surveys found a steeper frequency dependence for
sources just below the WMAP nominal threshold than the one estimated by the
WMAP team. This feature is present in our simulations and translates into a
shift of 0.3-0.4 \sigma in the estimated value of the tilt of the power
spectrum of scalar perturbation, n_s, as well as \omega_c. This approach
demonstrates the use of external point sources datasets for CMB data analysis.Comment: 12 pages, 8 figures, to be published on MNRA
Inconsistencies between physician-reported disclosures at the AAOS annual meeting and industry-reported financial disclosures in the open payments database
Stable non-uniform black strings below the critical dimension
The higher-dimensional vacuum Einstein equation admits translationally
non-uniform black string solutions. It has been argued that infinitesimally
non-uniform black strings should be unstable in 13 or fewer dimensions and
otherwise stable. We construct numerically non-uniform black string solutions
in 11, 12, 13, 14 and 15 dimensions. Their stability is investigated using
local Penrose inequalities. Weakly non-uniform solutions behave as expected.
However, in 12 and 13 dimensions, strongly non-uniform solutions appear to be
stable and can have greater horizon area than a uniform string of the same
mass. In 14 and 15 dimensions all non-uniform black strings appear to be
stable.Comment: 26 pages, 11 figures. V2: reference added, matches published versio
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