4,858 research outputs found

    Structure of the inner crust of neutron stars: crystal lattice or disordered phase ?

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    We investigate the inner crust structure of neutron stars using the Skyrme-Hartree-Fock approach with the Coulomb interaction treated beyond the Wigner-Seitz approximation. Our results suggest that the shell effects associated with unbound neutrons play an important role and, in particular, lead to complicated phase transition pattern between various nuclear phases (as a function of the density). Namely, we show that the relative energies of different phases are rapidly oscillating functions of the neutron density. In the semiclassical approach this behavior is explained as an interference effect due to periodic orbits of similar lengths. We discuss also the dependence of the shell effects on pairing correlations.Comment: 20 pages, 5 figure

    Integrating a Non-Uniformly Sampled Software Retina with a Deep CNN Model

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    We present a biologically inspired method for pre-processing images applied to CNNs that reduces their memory requirements while increasing their invariance to scale and rotation changes. Our method is based on the mammalian retino-cortical transform: a mapping between a pseudo-randomly tessellated retina model (used to sample an input image) and a CNN. The aim of this first pilot study is to demonstrate a functional retinaintegrated CNN implementation and this produced the following results: a network using the full retino-cortical transform yielded an F1 score of 0.80 on a test set during a 4-way classification task, while an identical network not using the proposed method yielded an F1 score of 0.86 on the same task. The method reduced the visual data by e×7, the input data to the CNN by 40% and the number of CNN training epochs by 64%. These results demonstrate the viability of our method and hint at the potential of exploiting functional traits of natural vision systems in CNNs

    The effect of external surface properties on the thermal behaviour of a transparently insulated wall

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    The properties of transparent plaster covering transparent insulation materials (TIM) were investigated using a whole building simulation program (ESP-r). The outer plaster was made from glass balls of different diameter, glued together with synthetic resin. The transmittance of the whole transparent covering layer (plaster + TIM) was estimated for different solar incident angles by laboratory measurements. The innovative character of the materials required refining of ESP-r's optical database in order to take into account these new characteristics. The transparently insulated building facade was proposed as a solar energy storage system. The results of the initial analysis showed the desirable optical properties, estimated for sun incident angles on the façade at a latitude of 52 degrees north. Then, simulations based on real climatic data for Central Europe were conducted to predict the thermal TIM wall behaviour. The influence of the structure on the diurnal heat storage potential was investigated for selected periods of the year

    Non-singular spacetimes with a negative cosmological constant: III. Stationary solutions with matter fields

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    Generalising the results in arXiv:1612.00281, we construct infinite-dimensional families of non-singular stationary space times, solutions of Yang-Mills-Higgs-Einstein-Maxwell-Chern-Simons-dilaton-scalar field equations with a negative cosmological constant. The families include an infinite-dimensional family of solutions with the usual AdS conformal structure at conformal infinity.Comment: 27 pages, v2: journal accepted versio

    Efficient Egocentric Visual Perception Combining Eye-tracking, a Software Retina and Deep Learning

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    We present ongoing work to harness biological approaches to achieving highly efficient egocentric perception by combining the space-variant imaging architecture of the mammalian retina with Deep Learning methods. By pre-processing images collected by means of eye-tracking glasses to control the fixation locations of a software retina model, we demonstrate that we can reduce the input to a DCNN by a factor of 3, reduce the required number of training epochs and obtain over 98% classification rates when training and validating the system on a database of over 26,000 images of 9 object classes.Comment: Accepted for: EPIC Workshop at the European Conference on Computer Vision, ECCV201

    Properties of nuclei in the neutron star crust

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    In the present study we investigate the static properties of nuclei in the inner crust of neutron stars. Using the Hartree-Fock method in coordinate space, together with the semiclassical approximation, we examine the patterns of phase transitions.Comment: 6 pages, 1 figure, presented at the Nuclear Many-Body Problem 2001 - NATO Advanced Research Workshop, June 1-6, Brijuni, Croatia, 200
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