12,183 research outputs found
The Cerevoice Blizzard Entry 2007: Are Small Database Errors Worse than Compression Artifacts?
In commercial systems the memory footprint of unit selection systems is often a key issue. This is especially true for PDAs and other embedded devices. In this years Blizzard entry CereProc R○gave itself the criteria that the full database system entered would have a smaller memory footprint than either of the two smaller database entries. This was accomplished by applying speex speech compression to the full database entry. In turn a set of small database techniques used to improve the quality of small database systems in last years entry were extended. Finally, for all systems, two quality control methods were applied to the underlying database to improve the lexicon and transcription match to the underlying data. Results suggest that mild audio quality artifacts introduced by lossy compression have almost as much impact on MOS perceived quality as concatenation errors introduced by sparse data in the smaller systems with bulked diphones. Index Terms: speech synthesis, unit selection. 1
Is the decoherence of a system the result of its interaction with the environment?
According to a usual reading, decoherence is a process resulting from the
interaction between a small system and its large environment where information
and energy are dissipated. The particular models treated in the literature on
the subject reinforce this idea since, in general, the behavior of a particle
immersed in a large "bath" composed by many particles is studied. The aim of
this letter is to warn against this usual simplified reading. By means of the
analysis of a well-known model, we will show that decoherence may occur in a
system interacting with an environment consisting of only one particle.Comment: 4 Pages, 5 Figure
Two Dimensional Ir-Cluster Lattices on Moir\'e of Graphene with Ir(111)
Lattices of Ir clusters have been grown by vapor phase deposition on graphene
moir\'{e}s on Ir(111). The clusters are highly ordered, spatially and thermally
stable below 500K. Their narrow size distribution is tunable from 4 to about
130 atoms. A model for cluster binding to the graphene is presented based on
scanning tunneling microscopy and density functional theory. The proposed
binding mechanism suggests that similar cluster lattices might be grown of
materials other than Ir.Comment: Submitted to PRL on 27Apr0
Impact of Weak Lensing Mass Calibration on eROSITA Galaxy Cluster Cosmological Studies -- a Forecast
We forecast the impact of weak lensing (WL) cluster mass calibration on the
cosmological constraints from the X-ray selected galaxy cluster counts in the
upcoming eROSITA survey. We employ a prototype cosmology pipeline to analyze
mock cluster catalogs. Each cluster is sampled from the mass function in a
fiducial cosmology and given an eROSITA count rate and redshift, where count
rates are modeled using the eROSITA effective area, a typical exposure time,
Poisson noise and the scatter and form of the observed X-ray luminosity-- and
temperature--mass--redshift relations. A subset of clusters have mock shear
profiles to mimic either those from DES and HSC or from the future Euclid and
LSST surveys. Using a count rate selection, we generate a baseline cluster
cosmology catalog that contains 13k clusters over 14,892~deg of
extragalactic sky. Low mass groups are excluded using raised count rate
thresholds at low redshift. Forecast parameter uncertainties for
, and are 0.023 (0.016; 0.014), 0.017 (0.012;
0.010), and 0.085 (0.074; 0.071), respectively, when adopting DES+HSC WL
(Euclid; LSST), while marginalizing over the sum of the neutrino masses. A
degeneracy between the distance--redshift relation and the parameters of the
observable--mass scaling relation limits the impact of the WL calibration on
the constraints, but with BAO measurements from DESI an improved
determination of to 0.043 becomes possible. With Planck CMB priors,
() can be determined to (), and the
summed neutrino mass limited to eV (at 95\%). If
systematics on the group mass scale can be controlled, the eROSITA group and
cluster sample with 43k objects and LSST WL could constrain
and to 0.007 and to 0.050.Comment: 28 pages, 13 figur
Nonequilibrium work distribution of a quantum harmonic oscillator
We analytically calculate the work distribution of a quantum harmonic
oscillator with arbitrary time-dependent angular frequency. We provide detailed
expressions for the work probability density for adiabatic and nonadiabatic
processes, in the limit of low and high temperature. We further verify the
validity of the quantum Jarzynski equalityComment: 6 pages, 3 figure
Long spin coherence times in the ground state and an optically excited state of Er:YSiO at zero magnetic field
Spins in solids are an ideal candidate to act as a memory and interface with
superconducting qubits due to their long coherence times. We spectroscopically
investigate erbium-167-doped yttrium orthosilicate as a possible
microwave-addressed memory employing its microwave frequency transitions that
occur without applying an external magnetic field. We obtain coherence times of
380 s in a ground state spin transition and 1.48 ms in an excited state
spin transition. This is 28 times longer compared to previous zero field
measurements, as well as 200 times longer than a previous microwave memory
demonstration in the same material. These long coherence times show that
erbium-167-doped yttrium orthosilicate has potential as a microwave-addressed
quantum memory.Comment: 9 pages, 7 figures. The paper has been expanded compared to the
previous version on arXiv, and the title has change
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