18,549 research outputs found

    3D MODELING of A COMPLEX BUILDING: From MULTI-VIEW IMAGE FUSION to GOOGLE EARTH PUBLICATION

    Get PDF
    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

    Full text link
    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

    Hybrid Neural Networks for Frequency Estimation of Unevenly Sampled Data

    Get PDF
    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

    The One Dimensional Damped Forced Harmonic Oscillator Revisited

    Full text link
    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

    First measurements of Collins and Sivers asymmetries at COMPASS

    Full text link
    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

    Hidden vortices in a Bose-Einstein condensate in a rotating double-well potential

    Full text link
    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

    Charged currents, color dipoles and xF_3 at small x

    Full text link
    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

    Microporous silicon dioxide/vycor membranes for gas separation

    Get PDF
    This study focused on producing membranes for molecular sieving of gases by reducing the pore size of an already existing membrane structure. To do this, SiO2 was deposited inside the pores of a Vycor tube with initial pore diameter of 4 nm. The film deposition took place by a low pressure chemical vapor deposition (LPCVD) process where diethylsilane (DES) and nitrous oxide (N2O) were used as precursor gases. A counterflow reactant geometry was used where the precursor gases were flowed on both sides of the porous membrane. This deposition geometry gave higher selectivities and better mechanical stability. The flows of H2, He, N2, Ar, toluene, and dichloromethane (DCM) were monitored in-situ after each deposition. Selectivities on the order of 1000:1 were observed for H2 and He over N2. It was also shown that N2/toluene selectivities of 40:1 were also possible
    corecore