1,746 research outputs found
Cepstral analysis based on the Glimpse proportion measure for improving the intelligibility of HMM-based synthetic speech in noise
In this paper we introduce a new cepstral coefficient extraction method based on an intelligibility measure for speech in noise, the Glimpse Proportion measure. This new method aims to increase the intelligibility of speech in noise by modifying the clean speech, and has applications in scenarios such as public announcement and car navigation systems. We first explain how the Glimpse Proportion measure operates and further show how we approximated it to integrate it into an existing spectral envelope parameter extraction method commonly used in the HMM-based speech synthesis framework. We then demonstrate how this new method changes the modelled spectrum according to the characteristics of the noise and show results for a listening test with vocoded and HMM-based synthetic speech. The test indicates that the proposed method can significantly improve intelligibility of synthetic speech in speech shaped noise. Index Terms — cepstral coefficient extraction, objective measure for speech intelligibility, Lombard speech, HMM-based speech synthesis 1
Proton decay in 5D SU(6) GUT with orbifold S^1/Z_2 breaking in Scherk-Schwarz mechanism
Proton decay within 5-dimensional SU(6) GUT with orbifold S^1/Z_2 breaking is
investigated using Scherk-Schwarz mechanism. It is shown that in the model
neither leptoquark like heavy gauge bosons nor violation of baryon number
conservation are allowed due to the orbifold breaking parity splitting. These
results prevent too short proton lifetime within the model.Comment: 6 pages, Proceeding of the Conference in Honour of Murray Gell-Mann's
80th Birthday : Quantum Mechanics, Elementary Particles, Quantum Cosmology,
Complexity (2011) 544-54
Dynamical symmetry breaking of SU(6) GUT in 5-dimensional spacetime with orbifold S1/Z2
The symmetry breaking of 5-dimensional SU(6) GUT into 4-dimensional SU(3) x
SU(3) x U(1) with orbifold S1/Z2 through Scherk-Schwarz mechanism is
investigated. It is shown that the origin of Little Higgs can be generated to
further break SU(3) x SU(3) x U(1) down to the electroweak scale through Higgs
mechanism.Comment: 4 page
Observational tests for oscillating expansion rate of the Universe
We investigate the observational constraints on the oscillating scalar field
model using data from type Ia supernovae, cosmic microwave background
anisotropies, and baryon acoustic oscillations. According to a Fourier
analysis, the galaxy number count from redshift data indicates that
galaxies have preferred periodic redshift spacings. We fix the mass of the
scalar field as such that the scalar
field model can account for the redshift spacings, and we constrain the other
basic parameters by comparing the model with accurate observational data. We
obtain the following constraints: (95% C.L.),
(95% C.L.) (in the range
). The best fit values of the energy density parameter of the scalar
field and the coupling constant are and ,
respectively. The value of is close to but not equal to .
Hence, in the scalar field model, the amplitude of the galaxy number count
cannot be large. However, because the best fit values of and
are not , the scalar field model has the possibility of accounting for
the periodic structure in the -- relation of galaxies. The variation of
the effective gravitational constant in the scalar field model is not
inconsistent with the bound from observation.Comment: 9 pages, 11 figures, 1 table, Accepted for publication in Physical
Review
Magnetic Helicity in Sphaleron Debris
We develop an analytical technique to evaluate the magnetic helicity in the
debris from sphaleron decay. We show that baryon number production leads to
left-handed magnetic fields, and that the magnetic helicity is conserved at
late times. Our analysis explicitly demonstrates the connection between
sphaleron-mediated cosmic baryogenesis and cosmic magnetogenesis.Comment: 9 pages, 1 figure. v2: Minor revisions; matches published version in
Physical Review
Crystal Nucleation in Liquids: Open Questions and Future Challenges in Molecular Dynamics Simulations
The nucleation of crystals in liquids is one of nature's most ubiquitous
phenomena, playing an important role in areas such as climate change and the
production of drugs. As the early stages of nucleation involve exceedingly
small time and length scales, atomistic computer simulations can provide unique
insight into the microscopic aspects of crystallization. In this review, we
take stock of the numerous molecular dynamics simulations that in the last few
decades have unraveled crucial aspects of crystal nucleation in liquids. We put
into context the theoretical framework of classical nucleation theory and the
state of the art computational methods, by reviewing simulations of e.g. ice
nucleation or crystallization of molecules in solutions. We shall see that
molecular dynamics simulations have provided key insight into diverse
nucleation scenarios, ranging from colloidal particles to natural gas hydrates,
and that in doing so the general applicability of classical nucleation theory
has been repeatedly called into question. We have attempted to identify the
most pressing open questions in the field. We believe that by improving (i.)
existing interatomic potentials; and (ii.) currently available enhanced
sampling methods, the community can move towards accurate investigations of
realistic systems of practical interest, thus bringing simulations a step
closer to experiments
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