7,327 research outputs found

    Detection of Review Abuse via Semi-Supervised Binary Multi-Target Tensor Decomposition

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    Product reviews and ratings on e-commerce websites provide customers with detailed insights about various aspects of the product such as quality, usefulness, etc. Since they influence customers' buying decisions, product reviews have become a fertile ground for abuse by sellers (colluding with reviewers) to promote their own products or to tarnish the reputation of competitor's products. In this paper, our focus is on detecting such abusive entities (both sellers and reviewers) by applying tensor decomposition on the product reviews data. While tensor decomposition is mostly unsupervised, we formulate our problem as a semi-supervised binary multi-target tensor decomposition, to take advantage of currently known abusive entities. We empirically show that our multi-target semi-supervised model achieves higher precision and recall in detecting abusive entities as compared to unsupervised techniques. Finally, we show that our proposed stochastic partial natural gradient inference for our model empirically achieves faster convergence than stochastic gradient and Online-EM with sufficient statistics.Comment: Accepted to the 25th ACM SIGKDD Conference on Knowledge Discovery and Data Mining, 2019. Contains supplementary material. arXiv admin note: text overlap with arXiv:1804.0383

    Lepton number violation via intermediate black hole processes

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    Black holes at the TeV scale are investigated in the extra large dimension scenario. We interpret the lightest black hole excitation as a singlet scalar field, and show how interaction terms can be appended to the standard model at the dimension five non-renormalizable level. Lepton family number violation is natural in this model. Muon magnetic moment, and neutrino masses are investigated. We also present a quantization scheme in n dimensions.Comment: 5 pages, 4 figure

    Cyclic variations in the ovarian activity of a fresh water perch Colisa fasciatus (Bl. & Schn.)

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    A morfologia geral, histologia e mudanças cĂ­clicas no ovĂĄrio de Colisa fasciatus foram descritas. 0 ovĂĄrio apresenta um tipo assincrĂŽnico de desenvolvimento ovocitĂĄrio, com um sĂł pico de desova que se estende de junho a agosto. 0 ooplasma, nĂșcleo e constituintes da parede celular exibem distintas mudanças morfolĂłgicas e histolĂłgicas durante seu ciclo anual. 0 aparecimento de nĂșcleos de vitelo, extrusĂ”es nucleolares e deposição de vitelo foram discutidas

    Analysis of the B→K2∗(→Kπ)l+l−B \to K^*_{2} (\to K \pi) l^+ l^- decay

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    In this paper we study the angular distribution of the rare B decay B→K2∗(→Kπ)l+l−B \to K^*_2 (\to K \pi) l^+ l^-, which is expected to be observed soon. We use the standard effective Hamiltonian approach, and use the form factors that have already been estimated for the corresponding radiative decay B→K2∗γB \to K^*_2 \gamma. The additional form factors that come into play for the dileptonic channel are estimated using the large energy effective theory (LEET), which enables one to relate the additional form factors to the form factors for the radiative mode. Our results provide, just like in the case of the K∗(892)K^*(892) resonance, an opportunity for a straightforward comparison of the basic theory with experimental results which may be expected in the near future for this channel.Comment: 14 pages, 5 figures; as accepted for Phys. Rev.

    Monitoring shoreline changes along Andhra coast of India using remote sensing and geographic information system

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    218-224A shoreline is dynamic in nature which makes the interface of land and water that offers socio-economic and cultural protection to its adjacent population. The purpose of this study was to understand long-term (1973-2015 and 2015-2057) shoreline transformation as well as the patterns of soil loss/sedimentation owing to physical and anthropogenic activities along the Andhra coast. Satellite imageries of LANDSAT from 1973 to 2015 were utilized to delineate the shoreline. Shoreline fluctuations were analyzed by Net Shoreline Movement (NSM) and End Point Rate (EPR) statistics using the Digital Shoreline Analysis System (DSAS) computer software of USGS. The highest and lowest EPR of about 67.63 m/y and -43.14 m/y were recorded in the Andhra coast. The high rate of deposition was recorded in the Godavari delta, whereas Krishna delta experienced low erosion. This study establishes the use of remote sensing data and statistical techniques such as EPR and NSM for shoreline monitoring are helpful for soil loss/accretion evaluation and future shoreline prediction

    Dissociative Autoionization in (1+2)-photon Above Threshold Excitation of H2 Molecules

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    We have theoretically studied the effect of dissociative autoionization on the photoelectron energy spectrum in (1+2)-photon above threshold ionization(ATI) of H2 molecules. We have considered excitation from the ground state X-singlet-Sigma-g+(v=0,j) to the doubly excited autoionizing states of singlet-Sigma-u+ and singlet-Pi-u+ symmetry, via the intermediate resonant B-singlet-Sigma-u+(v=5,j) states. We have shown that the photoelectron energy spectrum is oscillatory in nature and shows three distinct peaks above the photoelectron energy 0.7 eV. This feature has been observed in a recent experiment by Rottke et al, J. Phys. B, Vol. 30, p-4049 (1997).Comment: 11 pages and 4 figure
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