9,550 research outputs found
Creating temperature dependent Ni-MH battery models for low power mobile devices
In this paper the methodology and the results of creating temperature
dependent battery models for ambient intelligence applications is presented.
First the measurement technology and the model generation process is presented
in details, and then the characteristic features of the models are discussed.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Noble internal transport barriers and radial subdiffusion of toroidal magnetic lines
Single trajectories of magnetic line motion indicate the persistence of a
central protected plasma core, surrounded by a chaotic shell enclosed in a
double-sided transport barrier : the latter is identified as being composed of
two Cantori located on two successive "most-noble" numbers values of the
perturbed safety factor, and forming an internal transport barrier (ITB).
Magnetic lines which succeed to escape across this barrier begin to wander in a
wide chaotic sea extending up to a very robust barrier (as long as L<1) which
is identified mathematically as a robust KAM surface at the plasma edge. In
this case the motion is shown to be intermittent, with long stages of
pseudo-trapping in the chaotic shell, or of sticking around island remnants, as
expected for a continuous time random walk.Comment: TEX file, 84 pages including 32 color figures. Higher quality figures
can be seen on the PDF file at
http://membres.lycos.fr/fusionbfr/JHM/Tokamap/JSP.pd
Scalar mesons in a linear sigma model with (axial-)vector mesons
The structure of the scalar mesons has been a subject of debate for many
decades. In this work we look for states among the physical
resonances using an extended Linear Sigma Model that contains scalar,
pseudoscalar, vector, and axial-vector mesons both in the non-strange and
strange sectors. We perform global fits of meson masses, decay widths and
amplitudes in order to ascertain whether the scalar states are below
or above 1 GeV. We find the scalar states above 1 GeV to be preferred as
states.Comment: 6 pages, 1 figure, To appear in the proceedings of the XII. Hadron
Physics Conference, Bento Goncalves, Brasil, April, 22 - 27, 201
Elastic alpha-scattering of 112Sn and 124Sn at astrophysically relevant energies
The cross sections for the elastic scattering reactions
{112,124}Sn(a,a){112,124}Sn at energies above and below the Coulomb barrier are
presented and compared to predictions for global alpha-nucleus potentials. The
high precision of the new data allows a study of the global alpha-nucleus
potentials at both the proton and neutron-rich sides of an isotopic chain. In
addition, local alpha-nucleus potentials have been extracted for both nuclei,
and used to reproduce elastic scattering data at higher energies. Predictions
from the capture cross section of the reaction 112Sn(a,g)116Te at
astrophysically relevant energies are presented and compared to experimental
data.Comment: 20 pages, 10 figures, accepted for publication in Phys. Rev.
Sequential Symbolic Regression with Genetic Programming
This chapter describes the Sequential Symbolic Regression (SSR) method, a new strategy for function approximation in symbolic regression. The SSR method is inspired by the sequential covering strategy from machine learning, but instead of sequentially reducing the size of the
problem being solved, it sequentially transforms the original problem into potentially simpler problems. This transformation is performed according to the semantic distances between the desired and obtained outputs and a geometric semantic operator. The rationale behind SSR is that, after generating a suboptimal function f via symbolic regression, the output errors can be approximated by another function in a subsequent iteration. The method was tested in eight polynomial functions, and compared with canonical genetic programming (GP) and geometric semantic genetic programming (SGP). Results showed that SSR significantly outperforms SGP and presents no statistical difference to GP. More importantly, they show the potential of the proposed strategy: an effective way of applying geometric semantic operators to combine different (partial) solutions, avoiding the exponential growth problem arising from the use of these operators
Total reaction cross sections from elastic alpha-nucleus scattering angular distributions around the Coulomb barrier
The total reaction cross section is a valuable measure
for the prediction of -induced reaction cross sections within the
statistical model and for the comparison of scattering of tightly bound
projectiles to weakly bound and exotic projectiles. Here we provide the total
reaction cross sections derived from our previously
published angular distributions of -elastic scattering on Y,
Mo, Sn, and Sm at energies around the Coulomb
barrier.Comment: 4 pages, 2 figures, Phys. Rev. C, accepted as Brief Repor
Generalized Killing equations and Taub-NUT spinning space
The generalized Killing equations for the configuration space of spinning
particles (spinning space) are analysed. Simple solutions of the homogeneous
part of these equations are expressed in terms of Killing-Yano tensors. The
general results are applied to the case of the four-dimensional euclidean
Taub-NUT manifold.Comment: 10 pages, late
High precision Y(,)Y scattering at low energies
Elastic scattering cross sections of the Y(,)Y
reaction have been measured at energies E = 15.51 and 18.63 MeV. The
high precision data for the semi-magic nucleus Y are used to
derive a local potential and to evaluate the predictions of global and regional
-nucleus potentials. The variation of the elastic alpha scattering
cross sections along the isotonic chain is investigated by a study of
the ratios of angular distributions for Y(,)Y and
Mo(,)Mo at E 15.51 and 18.63
MeV. This ratio is a very sensitive probe at energies close to the Coulomb
barrier, where scattering data alone is usually not enough to characterize the
different potentials. Furthermore, -cluster states in Nb =
Y are investigated
Investigation of alpha-nuclear potential families from elastic scattering experiments
In this work we present the continuation of the reported analysis [1] of the experimentally measured angular distributions of the reaction Cd-106(alpha, alpha)Cd-106 at several different energies around the Coulomb barrier. The difficulties that arise in the study of Cd-106-alpha-nuclear potential and the so called Family Problem are addressed
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