22,513 research outputs found
3D MODELING of A COMPLEX BUILDING: From MULTI-VIEW IMAGE FUSION to GOOGLE EARTH PUBLICATION
This paper presents a pipeline that aims at illustrating the procedure to realize a 3D model of a complex building integrating the UAV and terrestrial images and modifying the 3D model in order to publish to Google Earth in an interactive modality so as to provide better available models for visualization and use. The main steps of the procedure are the optimization of the UAV flight, the integration of the different UAV and ground floor images and the optimization of the model to be published to GE. The case study has been identified in a building, The Eremo di Santa Rosalia Convent in Sicily which hash more staggered elevations and located in the hills of the hinterland and of which, the online platform only indicate the position on Google Maps (GM) and Google Earth (GE) with a photo from above and a non-urban road whose GM path is not corresponding with the GE photo. The process highlights the integration of the models and showcases a workflow for the publication of the combined 3D model to the GE platform
Observation of a New Fluxon Resonant Mechanism in Annular Josephson Tunnel Structures
A novel dynamical state has been observed in the dynamics of a perdurbed
sine-Gordon system. This resonant state, has been experimentally observed as a
singularity in the dc current voltage characteristic of an annular Josephson
tunnel junction, excited in the presence of a magnetic field. With this
respect, it can be assimilated to self-resonances known as Fiske steps.
Differently from these, however, we demonstrate, on the basis of numerical
simulations, that its detailed dynamics involves rotating fluxon pairs, a
mechanism associated, so far, to self-resonances known as zero-field steps.Comment: 4 pages, 2 figures, submitted to Physical Review Letter
First measurements of Collins and Sivers asymmetries at COMPASS
COMPASS is a fixed-target experiment on the SPS M2 beamline at CERN. Its LiD
target can be polarised both longitudinally and transversally with respect to
the longitudinally polarised 160 GeV/c muon beam. Approximately 20% of the
beam-time in 2002, 2003 and 2004 was spent in the transverse configuration,
allowing the first measurement of both the Collins and Sivers asymmetries on a
deuterium target. First results from the the transverse data of the COMPASS run
in 2002 are reported here.Comment: 4 pages, 1 figure, contribution to parallel session of BARYONS04, Oct
25-29 2004, Palaiseau, France Removed typo, corrected erroneous referenc
The One Dimensional Damped Forced Harmonic Oscillator Revisited
In this paper we give a general solution to the problem of the damped
harmonic oscillator under the influence of an arbitrary time-dependent external
force. We employ simple methods accessible for beginners and useful for
undergraduate students and professors in an introductory course of mechanics.Comment: 4 Latex page
Hidden vortices in a Bose-Einstein condensate in a rotating double-well potential
We study vortex formation in a Bose-Einstein condensate in a rotating
double-well potential. Besides the ordinary quantized vortices and elusive
ghost vortices, "hidden" vortices are found distributing along the central
barrier. These hidden vortices are invisible like ghost vortex but carry
angular momentum. Moreover, their core size is not given by the healing length,
but is strongly influenced by the external potential. We find that the
Feynman's rule can be well satisfied only after including the hidden vortices.
There is no critical rotating frequency for the formation of hidden vortex
while there is one for the formation of ordinary visible vortices. Hidden
vortices can be revealed in the free expansion of the Bose-Einstein
condensates. In addition, the hidden vortices in a Bose-Einstein condensate can
appear in other external potentials, such as a rotating anisotropic toroidal
trap.Comment: 6pages,5figure
Transversity from two pion interference fragmentation
We present calculation on the azimuthal spin asymmetries for pion pair
production in semi-inclusive deep inelastic scattering (SIDIS) process at both
HERMES and COMPASS kinematics, with transversely polarized proton, deuteron and
neutron targets. We calculate the asymmetry by adopting a set of
parametrization of the interference fragmentation functions and two different
models for the transversity. We find that the result for the proton target is
insensitive to the approaches of the transversity but more helpful to
understand the interference fragmentation functions. However, for the neutron
target, which can be obtained through using deuteron and {He} targets, we
find different predictions for different approaches to the transversity. Thus
probing the two pion interference fragmentation from the neutron can provide us
more interesting information on the transversity.Comment: 15 latex pages, 6 figures, to appear in PR
Charged currents, color dipoles and xF_3 at small x
We develop the light-cone color dipole description of highly asymmetric
diffractive interactions of left-handed and right-handed electroweak bosons. We
identify the origin and estimate the strength of the left-right asymmetry
effect in terms of the light-cone wave functions. We report an evaluation of
the small-x neutrino-nucleon DIS structure functions xF_3 and 2xF_1 and present
comparison with experimental data.Comment: 11 pages, 3 figures, misprints correcte
Nonlinear response of a thin metamaterial film containing Josephson junctions
An interaction of electromagnetic field with metamaterial thin film
containing split-ring resonators with Josephson junctions is considered. It is
shown that dynamical self-inductance in a split rings results in reduction of
magnetic flux through a ring and this reduction is proportional to a time
derivative of split ring magnetization. Evolution of thin film magnetization
taking into account dynamical self-inductance is studied. New mechanism for
excitation of waves in one dimensional array of split-ring resonators with
Josephson junctions is proposed. Nonlinear magnetic susceptibility of such thin
films is obtained in the weak amplitude approximation.Comment: 6 figure
Nonlinear dynamics, rectification, and phase locking for particles on symmetrical two-dimensional periodic substrates with dc and circular ac drives
We investigate the dynamical motion of particles on a two-dimensional
symmetric periodic substrate in the presence of both a dc drive along a
symmetry direction of the periodic substrate and an additional circular ac
drive. For large enough ac drives, the particle orbit encircles one or more
potential maxima of the periodic substrate. In this case, when an additional
increasing dc drive is applied in the longitudinal direction, the longitudinal
velocity increases in a series of discrete steps that are integer multiples of
the lattice constant of the substrate times the frequency. Fractional steps can
also occur. These integer and fractional steps correspond to distinct stable
dynamical orbits. A number of these phases also show a rectification in the
positive or negative transverse direction where a non-zero transverse velocity
occurs in the absence of a dc transverse drive. We map out the phase diagrams
of the regions of rectification as a function of ac amplitude, and find a
series of tongues. Most of the features, including the steps in the
longitudinal velocity and the transverse rectification, can be captured with a
simple toy model and by arguments from nonlinear maps. We have also
investigated the effects of thermal disorder and incommensuration on the
rectification phenomena, and find that for increasing disorder, the
rectification regions are gradually smeared and the longitudinal velocity steps
are no longer flat but show a linearly increasing velocity.Comment: 14 pages, 17 postscript figure
Hybrid Neural Networks for Frequency Estimation of Unevenly Sampled Data
In this paper we present a hybrid system composed by a neural network based
estimator system and genetic algorithms. It uses an unsupervised Hebbian
nonlinear neural algorithm to extract the principal components which, in turn,
are used by the MUSIC frequency estimator algorithm to extract the frequencies.
We generalize this method to avoid an interpolation preprocessing step and to
improve the performance by using a new stop criterion to avoid overfitting.
Furthermore, genetic algorithms are used to optimize the neural net weight
initialization. The experimental results are obtained comparing our methodology
with the others known in literature on a Cepheid star light curve.Comment: 5 pages, to appear in the proceedings of IJCNN 99, IEEE Press, 199
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