109,165 research outputs found

    The effect of the initial layer on the reversal mechanism in CoCr films

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    The dependence of OR, H/sub c/, and hysteresis loss is measured as functions of the angle with the applied field (H/sub a/) as a parameter. It is reported that with increasing H/sub c/ perpendicular to /H/sub k/ values the orientation direction of the magnetization gradually changes from in-plane (OR/sub perpendicular to /=0.7) to perpendicular (OR/sub perpendicular to /=3.9). The angular dependence of H/sub c/ is closely related to the value of H/sub a/. It was found that H/sub c//H/sub c perpendicular to / drastically decreases at H/sub a/=H/sub c perpendicular to max/ (159 kA/m) with decreasing H/sub a/. The influence of the demagnetizing field on the angular dependence of the magnetic behavior in CoCr films is also examined

    Einstein-Gauss-Bonnet Black Strings at Large DD

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    We study the black string solutions in the Einstein-Gauss-Bonnet(EGB) theory at large DD. By using the 1/D1/D expansion in the near horizon region we derive the effective equations that describe the dynamics of the EGB black strings. The uniform and non-uniform black strings are obtained as the static solutions of the effective equations. From the perturbation analysis of the effective equations, we find that thin EGB black strings suffer from the Gregory-Laflamme instablity and the GB term weakens the instability when the GB coefficient is small, however, when the GB coefficient is large the GB term enhances the instability. Furthermore, we numerically solve the effective equations to study the non-linear instability. It turns out that the thin black strings are unstable to developing inhomogeneities along their length, and at late times they asymptote to the stable non-uniform black strings. The behavior is qualitatively similar to the case in the Einstein gravity. Compared with the black string instability in the Einstein gravity at large D, when the GB coefficient is small the time needed to reach to final state increases, but when the GB coefficient is large the time to reach to final state decreases. Starting from the point of view in which the effective equations can be interpreted as the equations for the dynamical fluid, we evaluate the transport coefficients and find that the ratio of the shear viscosity and the entropy density agrees with that obtained previously in the membrane paradigm after taking the large DD limit.Comment: 22 pages, 8 figures, some errors corrected, references adde

    Weak Poincar\'e Inequality for Convolution Probability Measures

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    By using Lyapunov conditions, weak Poincar\'e inequalities are established for some probability measures on a manifold (M,g)(M,g). These results are further applied to the convolution of two probability measures on Rd\R^d. Along with explicit results we study concrete examples

    Holographic Turbulence in Einstein-Gauss-Bonnet Gravity at Large DD

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    We study the holographic hydrodynamics in the Einstein-Gauss-Bonnet(EGB) gravity in the framework of the large DD expansion. We find that the large DD EGB equations can be interpreted as the hydrodynamic equations describing the conformal fluid. These fluid equations are truncated at the second order of the derivative expansion, similar to the Einstein gravity at large DD. From the analysis of the fluid flows, we find that the fluid equations can be taken as a variant of the compressible version of the non-relativistic Navier-Stokes equations. Particularly, in the limit of small Mach number, these equations could be cast into the form of the incompressible Navier-Stokes equations with redefined Reynolds number and Mach number. By using numerical simulation, we find that the EGB holographic turbulence shares similar qualitative feature as the turbulence from the Einstein gravity, despite the presence of two extra terms in the equations of motion. We analyze the effect of the GB term on the holographic turbulence in detail.Comment: 30 pages, 11 figure

    Quantifying Facial Age by Posterior of Age Comparisons

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    We introduce a novel approach for annotating large quantity of in-the-wild facial images with high-quality posterior age distribution as labels. Each posterior provides a probability distribution of estimated ages for a face. Our approach is motivated by observations that it is easier to distinguish who is the older of two people than to determine the person's actual age. Given a reference database with samples of known ages and a dataset to label, we can transfer reliable annotations from the former to the latter via human-in-the-loop comparisons. We show an effective way to transform such comparisons to posterior via fully-connected and SoftMax layers, so as to permit end-to-end training in a deep network. Thanks to the efficient and effective annotation approach, we collect a new large-scale facial age dataset, dubbed `MegaAge', which consists of 41,941 images. Data can be downloaded from our project page mmlab.ie.cuhk.edu.hk/projects/MegaAge and github.com/zyx2012/Age_estimation_BMVC2017. With the dataset, we train a network that jointly performs ordinal hyperplane classification and posterior distribution learning. Our approach achieves state-of-the-art results on popular benchmarks such as MORPH2, Adience, and the newly proposed MegaAge.Comment: To appear on BMVC 2017 (oral) revised versio
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