4,334 research outputs found
Turing machines based on unsharp quantum logic
In this paper, we consider Turing machines based on unsharp quantum logic.
For a lattice-ordered quantum multiple-valued (MV) algebra E, we introduce
E-valued non-deterministic Turing machines (ENTMs) and E-valued deterministic
Turing machines (EDTMs). We discuss different E-valued recursively enumerable
languages from width-first and depth-first recognition. We find that
width-first recognition is equal to or less than depth-first recognition in
general. The equivalence requires an underlying E value lattice to degenerate
into an MV algebra. We also study variants of ENTMs. ENTMs with a classical
initial state and ENTMs with a classical final state have the same power as
ENTMs with quantum initial and final states. In particular, the latter can be
simulated by ENTMs with classical transitions under a certain condition. Using
these findings, we prove that ENTMs are not equivalent to EDTMs and that ENTMs
are more powerful than EDTMs. This is a notable difference from the classical
Turing machines.Comment: In Proceedings QPL 2011, arXiv:1210.029
Energy Loss Signals in the ALICE TRD
We present the energy loss measurements with the ALICE TRD in the
range 1--10, where and
. The measurements are conducted in three different
scenarios: 1) with pions and electrons from testbeams; 2) with protons, pions
and electrons in proton-proton collisions at center-of-mass energy 7 TeV; 3)
with muons detected in ALICE cosmic runs. In the testbeam and cosmic ray
measurements, ionization energy loss (dE/dx) signal as well as ionization
energy loss plus transition radiation (dE/dx+TR) signal are measured. With
cosmic muons the onset of TR is observed. Signals from TeV cosmic muons are
consistent with those from GeV electrons in the other measurements. Numerical
descriptions of the signal spectra and the -dependence of the most
probable signals are also presented.Comment: Proceedings for the 4th Workshop on Advanced Transition Radiation
Detectors for Accelerator and Space Applications, 14-16 September 2011, Bari,
Ital
Adaptive DCTNet for Audio Signal Classification
In this paper, we investigate DCTNet for audio signal classification. Its
output feature is related to Cohen's class of time-frequency distributions. We
introduce the use of adaptive DCTNet (A-DCTNet) for audio signals feature
extraction. The A-DCTNet applies the idea of constant-Q transform, with its
center frequencies of filterbanks geometrically spaced. The A-DCTNet is
adaptive to different acoustic scales, and it can better capture low frequency
acoustic information that is sensitive to human audio perception than features
such as Mel-frequency spectral coefficients (MFSC). We use features extracted
by the A-DCTNet as input for classifiers. Experimental results show that the
A-DCTNet and Recurrent Neural Networks (RNN) achieve state-of-the-art
performance in bird song classification rate, and improve artist identification
accuracy in music data. They demonstrate A-DCTNet's applicability to signal
processing problems.Comment: International Conference of Acoustic and Speech Signal Processing
(ICASSP). New Orleans, United States, March, 201
Strong enhancement of chlorophyll a concentration by a weak typhoon
Recent studies demonstrate that chlorophyll a (chl a) concentrations in the
surface ocean can be significantly enhanced due to typhoons. The present study
investigated chl a concentrations in the middle of the South China Sea (SCS)
from 1997-2007. Only the Category1 (minimal) Typhoon Hagibis (2007) had a
notable effect on the chl a concentrations. Typhoon Hagibis had a strong
upwelling potential due to its location near the equator, and the forcing time
of the typhoon (>82 h) was much longer than the geostrophic adjustment time
(~63 h). The higher upwelling velocity and the longer forcing time increased
the depth of the mixed-layer, which consequently induced a strong phytoplankton
bloom that accounted for about 30% of the total annual chl a concentration in
the middle of the SCS. The implication is that the forcing time of a typhoon
should be long enough to establish a strong upwelling and consequently for the
induction of significant upper ocean responses.Comment: Typhoon-Ocean Environment interaction
Controllable Operations of Edge States in Cross-One-dimensional Topological Chains
Topological edge states are recently attracting intense interest due to their
robustness in the presence of disorder and defects. However, most approaches
for manipulating such states require global modulations of the system's
Hamiltonian. In this work, we develop a method to control edge states using
local interactions of a four-node junction between cross-one-dimensional
topological atomic chains. These junction interactions can give rise to tunable
couplings between the hybridized edge states within different geometric
symmetry, allowing us to implement robust quantum state transfer and SWAP gate
between the two topological chains, where the edge states are pair-encoded as a
single qubit. Moreover, when the atoms are precisely positioned to couple
waveguides, the correlated decay caused by the environment enables the
anti-symmetric edge states to present subradiant dynamics and thus show
extremely long coherence time. These findings open up new possibilities for
quantum technologies with topological edge states in the future.Comment: 7 pages, 4 figure
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