2,174 research outputs found
Chord Label Personalization through Deep Learning of Integrated Harmonic Interval-based Representations
The increasing accuracy of automatic chord estimation systems, the
availability of vast amounts of heterogeneous reference annotations, and
insights from annotator subjectivity research make chord label personalization
increasingly important. Nevertheless, automatic chord estimation systems are
historically exclusively trained and evaluated on a single reference
annotation. We introduce a first approach to automatic chord label
personalization by modeling subjectivity through deep learning of a harmonic
interval-based chord label representation. After integrating these
representations from multiple annotators, we can accurately personalize chord
labels for individual annotators from a single model and the annotators' chord
label vocabulary. Furthermore, we show that chord personalization using
multiple reference annotations outperforms using a single reference annotation.Comment: Proceedings of the First International Conference on Deep Learning
and Music, Anchorage, US, May, 2017 (arXiv:1706.08675v1 [cs.NE]
Microoptical Realization of Arrays of Selectively Addressable Dipole Traps: A Scalable Configuration for Quantum Computation with Atomic Qubits
We experimentally demonstrate novel structures for the realisation of
registers of atomic qubits: We trap neutral atoms in one and two-dimensional
arrays of far-detuned dipole traps obtained by focusing a red-detuned laser
beam with a microfabricated array of microlenses. We are able to selectively
address individual trap sites due to their large lateral separation of 125 mu
m. We initialize and read out different internal states for the individual
sites. We also create two interleaved sets of trap arrays with adjustable
separation, as required for many proposed implementations of quantum gate
operations
GRB 050408: An Atypical Gamma-Ray Burst as a Probe of an Atypical Galactic Environment
The bright GRB 050408 was localized by HETE-II near local midnight, enabling
an impressive ground-based followup effort as well as space-based followup from
Swift. The Swift data from the X-Ray Telescope (XRT) and our own optical
photometry and spectrum of the afterglow provide the cornerstone for our
analysis. Under the traditional assumption that the visible waveband was above
the peak synchrotron frequency and below the cooling frequency, the optical
photometry from 0.03 to 5.03 days show an afterglow decay corresponding to an
electron energy index of p_lc = 2.05 +/- 0.04, without a jet break as suggested
by others. A break is seen in the X-ray data at early times (at ~12600 sec
after the GRB). The spectral slope of the optical spectrum is consistent with
p_lc assuming a host-galaxy extinction of A_V = 1.18 mag. The optical-NIR
broadband spectrum is also consistent with p = 2.05, but prefers A_V = 0.57
mag. The X-ray afterglow shows a break at 1.26 x 10^4 sec, which may be the
result of a refreshed shock. This burst stands out in that the optical and
X-ray data suggest a large H I column density of N_HI ~ 10^22 cm^-2; it is very
likely a damped Lyman alpha system and so the faintness of the host galaxy (M_V
> -18 mag) is noteworthy. Moreover, we detect extraordinarily strong Ti II
absorption lines with a column density through the GRB host that exceeds the
largest values observed for the Milky Way by an order of magnitude.
Furthermore, the Ti II equivalent width is in the top 1% of Mg II
absorption-selected QSOs. This suggests that the large-scale environment of GRB
050408 has significantly lower Ti depletion than the Milky Way and a large
velocity width (delta v > 200 km/s).Comment: ApJ submitte
Dust Dynamics in Compressible MHD Turbulence
We calculate the relative grain-grain motions arising from interstellar
magnetohydrodynamic (MHD) turbulence. The MHD turbulence includes both fluid
motions and magnetic fluctuations. While the fluid motions accelerate grains
through hydro-drag, the electromagnetic fluctuations accelerate grains through
resonant interactions. We consider both incompressive (Alfv\'{e}n) and
compressive (fast and slow) MHD modes and use descriptions of MHD turbulence
obtained in Cho & Lazarian (2002). Calculations of grain relative motion are
made for realistic grain charging and interstellar turbulence that is
consistent with the velocity dispersions observed in diffuse gas, including
cutoff of the turbulence from various damping processes. We show that fast
modes dominate grain acceleration, and can drive grains to supersonic
velocities. Grains are also scattered by gyroresonance interactions, but the
scattering is less important than acceleration for grains moving with
sub-Alfv\'{e}nic velocities. Since the grains are preferentially accelerated
with large pitch angles, the supersonic grains will be aligned with long axes
perpendicular to the magnetic field. We compare grain velocities arising from
MHD turbulence with those arising from photoelectric emission, radiation
pressure and H thrust. We show that for typical interstellar conditions
turbulence should prevent these mechanisms from segregating small and large
grains. Finally, gyroresonant acceleration is bound to preaccelerate grains
that are further accelerated in shocks. Grain-grain collisions in the shock may
then contribute to the overabundance of refractory elements in the composition
of galactic cosmic rays.Comment: 15 pages, 17 figure
Efficiency of Nonlinear Particle Acceleration at Cosmic Structure Shocks
We have calculated the evolution of cosmic ray (CR) modified astrophysical
shocks for a wide range of shock Mach numbers and shock speeds through
numerical simulations of diffusive shock acceleration (DSA) in 1D quasi-
parallel plane shocks. The simulations include thermal leakage injection of
seed CRs, as well as pre-existing, upstream CR populations. Bohm-like diffusion
is assumed. We model shocks similar to those expected around cosmic structure
pancakes as well as other accretion shocks driven by flows with upstream gas
temperatures in the range K and shock Mach numbers spanning
. We show that CR modified shocks evolve to time-asymptotic states
by the time injected particles are accelerated to moderately relativistic
energies (p/mc \gsim 1), and that two shocks with the same Mach number, but
with different shock speeds, evolve qualitatively similarly when the results
are presented in terms of a characteristic diffusion length and diffusion time.
For these models the time asymptotic value for the CR acceleration efficiency
is controlled mainly by shock Mach number. The modeled high Mach number shocks
all evolve towards efficiencies %, regardless of the upstream CR
pressure. On the other hand, the upstream CR pressure increases the overall CR
energy in moderate strength shocks (). (abridged)Comment: 23 pages, 12 ps figures, accepted for Astrophysical Journal (Feb. 10,
2005
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INVESTIGATION OF MULTI-MATERIAL LIQUID METAL JETTING WITH COPPER MATERIALS
Technical parts are typically subject to various requirements that may conflict with each
other. Multi-material parts can be a way to overcome such conflicting goals. Liquid Metal Jetting
(LMJ) can be a promising additive manufacturing process for the production of multi-material
copper parts with high geometric complexity. Since LMJ builds up a part droplet by droplet, there
are no mixed powders after printing. In addition, LMJ offers the possibility of changing materials
from droplet to droplet. In previous studies, we have shown that it is possible to produce copper
alloy parts using LMJ. In this work, we produced multi-material copper specimens at different
process parameters to investigate the manufacturing of multi-material copper parts. The
investigations show that the quality of the compound and the microstructure depend significantly
on the thermal process parameters used.Mechanical Engineerin
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