14,683 research outputs found
Joint observations of 4U1223-62 by the SAS-3 satellite and Columbia University proportional counter experiment on NASA rocket 26.054 UH
The pulsating X-ray binary 4U1223-62 and Vela X-1 were observed by Aerobee rocket-borne proportional counters. Valid X-ray events were telemetered and analyzed for possible flaring, quasiperiodic, and periodic pulsations, and for other nonstatistical behavior in the source. Both fast Fourier transform and autocorrelation programs were used. For several hours four days before and after the rocket flight, the SAS-3 satellite scanned the galactic plane in order to identify X-ray sources in the vicinity of 4U1223-62 and their intensities, and to provide positional accuracy of 0.25 for sources with intensity greater than 10% of the target. Observations of the source near the main peak of its pulsating period as defined by SAS-3 are discussed. There is no evidence of a spectral feature although twice as many photons were received as than from Vela X-1
High speed binary to decimal conversion system Patent
Design and operation of high speed binary to decimal conversion syste
Green's Functions from Quantum Cluster Algorithms
We show that cluster algorithms for quantum models have a meaning independent
of the basis chosen to construct them. Using this idea, we propose a new method
for measuring with little effort a whole class of Green's functions, once a
cluster algorithm for the partition function has been constructed. To explain
the idea, we consider the quantum XY model and compute its two point Green's
function in various ways, showing that all of them are equivalent. We also
provide numerical evidence confirming the analytic arguments. Similar
techniques are applicable to other models. In particular, in the recently
constructed quantum link models, the new technique allows us to construct
improved estimators for Wilson loops and may lead to a very precise
determination of the glueball spectrum.Comment: 15 pages, LaTeX, with four figures. Added preprint numbe
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Magma volume, volatile emissions, and stratospheric aerosols from the 1815 eruption of Tambora
We suggest that the Tambora 1815 eruption was smaller than previously thought, yielding 30–33 km3 of magma. Valuable insight into the eruption is gained by comparing it to the much smaller 1991 Pinatubo event, which had a similar eruption style and rate. By measuring pre- and post-eruption sulfur concentrations in 1815 ejecta, we estimate that Tambora released 53–58 Tg (5.3–5.8 × 1013 g) of SO2 within a period of about 24 hours on 10–11 April, 1815. This was sufficient to generate between 93 and 118 Tg of stratospheric sulfate aerosols. A value within this range, distributed globally, agrees well with estimates of aerosol mass from ice-core acidity and the radiative impact of the eruption. In contrast to other recent explosive arc eruptions, the Tambora ejecta retain a record of the sulfur mass released, with no “excess sulfur”
Critical exponents of a three dimensional O(4) spin model
By Monte Carlo simulation we study the critical exponents governing the
transition of the three-dimensional classical O(4) Heisenberg model, which is
considered to be in the same universality class as the finite-temperature QCD
with massless two flavors. We use the single cluster algorithm and the
histogram reweighting technique to obtain observables at the critical
temperature. After estimating an accurate value of the inverse critical
temperature \Kc=0.9360(1), we make non-perturbative estimates for various
critical exponents by finite-size scaling analysis. They are in excellent
agreement with those obtained with the expansion method with
errors reduced to about halves of them.Comment: 25 pages with 8 PS figures, LaTeX, UTHEP-28
A Swendsen-Wang update algorithm for the Symanzik improved sigma model
We study a generalization of Swendsen-Wang algorithm suited for Potts models
with next-next-neighborhood interactions. Using the embedding technique
proposed by Wolff we test it on the Symanzik improved bidimensional non-linear
model. For some long range observables we find a little slowing down
exponent () that we interpret as an effect of the partial
frustration of the induced spin model.Comment: Self extracting archive fil
The Tails of the Crossing Probability
The scaling of the tails of the probability of a system to percolate only in
the horizontal direction was investigated numerically for correlated
site-bond percolation model for .We have to demonstrate that the
tails of the crossing probability far from the critical point have shape
where is the correlation
length index, is the probability of a bond to be closed. At
criticality we observe crossover to another scaling . Here is a scaling index describing the
central part of the crossing probability.Comment: 20 pages, 7 figures, v3:one fitting procedure is changed, grammatical
change
A Convolutional-Attentional Neural Framework for Structure-Aware Performance-Score Synchronization
Performance-score synchronization is an integral task in signal processing,
which entails generating an accurate mapping between an audio recording of a
performance and the corresponding musical score. Traditional synchronization
methods compute alignment using knowledge-driven and stochastic approaches, and
are typically unable to generalize well to different domains and modalities. We
present a novel data-driven method for structure-aware performance-score
synchronization. We propose a convolutional-attentional architecture trained
with a custom loss based on time-series divergence. We conduct experiments for
the audio-to-MIDI and audio-to-image alignment tasks pertained to different
score modalities. We validate the effectiveness of our method via ablation
studies and comparisons with state-of-the-art alignment approaches. We
demonstrate that our approach outperforms previous synchronization methods for
a variety of test settings across score modalities and acoustic conditions. Our
method is also robust to structural differences between the performance and
score sequences, which is a common limitation of standard alignment approaches.Comment: Published in IEEE Signal Processing Letters, Volume 29, December 202
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