4,652 research outputs found

    BaFe2Se2O as an Iron-Based Mott Insulator with Antiferromagnetic Order

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    A new compound with a quasi-two-dimensional array of FeSe3O tetrahedra and an orthorombic structure, namely BaFe2Se2O, has been successfully fabricated. Experimental results show that this compound is an insulator and has an antiferromagnetic (AF) transition at 240 K. Band structure calculation reveals the narrowing of Fe 3d bands near the Fermi energy, which leads to the localization of magnetism and the Mott insulating behavior. The large distances between the Fe atoms perhaps are responsible for the characters. Linear response calculation further indicates a strong in-plane AF exchange JJ, this can account for the enhanced magnetic susceptibility (which has a maximum at about 450 K) above the Neel temperature.Comment: submitted to PRL on 2 May 2012, resubmitted to PRB on 31 May 2012, and accepted by PRB on 5 July 201

    Automatic skin segmentation for gesture recognition combining region and support vector machine active learning

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    Skin segmentation is the cornerstone of many applications such as gesture recognition, face detection, and objectionable image filtering. In this paper, we attempt to address the skin segmentation problem for gesture recognition. Initially, given a gesture video sequence, a generic skin model is applied to the first couple of frames to automatically collect the training data. Then, an SVM classifier based on active learning is used to identify the skin pixels. Finally, the results are improved by incorporating region segmentation. The proposed algorithm is fully automatic and adaptive to different signers. We have tested our approach on the ECHO database. Comparing with other existing algorithms, our method could achieve better performance
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