1,013 research outputs found

    REGRESSIONS FOR SUMS OF SQUARES OF SPACINGS

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    Abstract. Starting with a new formula for the regression of sum of squares of spacings (SSS) with respect to the maximum we present a characterization of a family of beta type mixtures in terms of the constancy of regression of normalized SSS of order statistics. Related characterization for records describes a family of minima of independent Weibull distributions

    Modeling the Temporal Nature of Human Behavior for Demographics Prediction

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    Mobile phone metadata is increasingly used for humanitarian purposes in developing countries as traditional data is scarce. Basic demographic information is however often absent from mobile phone datasets, limiting the operational impact of the datasets. For these reasons, there has been a growing interest in predicting demographic information from mobile phone metadata. Previous work focused on creating increasingly advanced features to be modeled with standard machine learning algorithms. We here instead model the raw mobile phone metadata directly using deep learning, exploiting the temporal nature of the patterns in the data. From high-level assumptions we design a data representation and convolutional network architecture for modeling patterns within a week. We then examine three strategies for aggregating patterns across weeks and show that our method reaches state-of-the-art accuracy on both age and gender prediction using only the temporal modality in mobile metadata. We finally validate our method on low activity users and evaluate the modeling assumptions.Comment: Accepted at ECML 2017. A previous version of this paper was titled 'Using Deep Learning to Predict Demographics from Mobile Phone Metadata' and was accepted at the ICLR 2016 worksho

    Density-functional embedding using a plane-wave basis

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    The constrained electron density method of embedding a Kohn-Sham system in a substrate system (first described by P. Cortona, Phys. Rev. B {\bf 44}, 8454 (1991) and T.A. Wesolowski and A. Warshel, J. Phys. Chem {\bf 97}, 8050 (1993)) is applied with a plane-wave basis and both local and non-local pseudopotentials. This method divides the electron density of the system into substrate and embedded electron densities, the sum of which is the electron density of the system of interest. Coupling between the substrate and embedded systems is achieved via approximate kinetic energy functionals. Bulk aluminium is examined as a test case for which there is a strong interaction between the substrate and embedded systems. A number of approximations to the kinetic-energy functional, both semi-local and non-local, are investigated. It is found that Kohn-Sham results can be well reproduced using a non-local kinetic energy functional, with the total energy accurate to better than 0.1 eV per atom and good agreement between the electron densities.Comment: 11 pages, 4 figure

    Application of macro-fiber composite (MFC) as a piezoelectric actuator

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    The aim of the present work is to investigate the use of Macro Fiber Composite (MFC) actuator for modal analysis of composite plate. Efficiency of application of MFC as an actuator in comparison with the impact hammer, PZT actuator and modal shaker has been investigated. POLYTEC laser Vibrometer operating on the Doppler principle and measuring back-scattered light from a vibrating panel has been used to determine its vibration velocity and displacement. Modal analysis is subsequently applied to extract natural frequencies and mode shape

    On Abelian Multi-Chern-Simons Field Theories

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    In this paper a class of multi-Chern-Simons field theories which is relevant to the statistical mechanics of polymer systems is investigated. Motivated by the problems which one encounters in the treatment of these theories, a general procedure is presented to eliminate the Chern-Simons fields from their action. In this way it has been possible to derive an expression of the partition function of topologically linked polymers which depends explicitly on the topological numbers and does not have intractable nonlocal terms as it happened in previous approaches. The new formulation of multi-Chern-Simons field theories is then used to remove and clarify some inconsistencies and ambiguities which apparently affect field theoretical models of topologically linked polymers. Finally, the limit of disentangled polymers is discussed.Comment: 18 pages, plain LaTe
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