11,403 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

    Electro-Reflectance Spectra of Blue Bronze

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    We show that the infrared reflectance of the quasi-one dimensional charge-density-wave (CDW) conductor K0.3MoO3 (blue bronze) varies with position when a voltage greater than the CDW depinning threshold is applied. The spatial dependence and spectra associated with these changes are generally as expected from the electro-transmission [B.M. Emerling, et al, Eur. Phys. J. B 16, 295 (2000)], but there are some differences which might be associated with changes in the CDW properties on the surface. We have examined the electro-reflectance spectrum associated with CDW current investigation for light polarized parallel to the conducting chains for signs of expected current-induced intragap states, and conclude that the density of any such states is at least an order of magnitude lower than expected.Comment: 1)submitted to Eur. Phys. J B 2) revised (July 24) to a) better emphasize results and b) with new figure insets to make paper more self-containe

    A Product Life Cycle Ontology for Additive Manufacturing

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    The manufacturing industry is evolving rapidly, becoming more complex, more interconnected, and more geographically distributed. Competitive pressure and diversity of consumer demand are driving manufacturing companies to rely more and more on improved knowledge management practices. As a result, multiple software systems are being created to support the integration of data across the product life cycle. Unfortunately, these systems manifest a low degree of interoperability, and this creates problems, for instance when different enterprises or different branches of an enterprise interact. Common ontologies (consensus-based controlled vocabularies) have proved themselves in various domains as a valuable tool for solving such problems. In this paper, we present a consensus-based Additive Manufacturing Ontology (AMO) and illustrate its application in promoting re-usability in the field of dentistry product manufacturing

    Masses and decay modes of charmonia using a confinement model

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    The masses of charmonium s and p-states, pseudoscalar and vector decay constants, leptonic, hadronic as well as radiative decay widths for charmonia have been computed in the framework of extended harmonic confinement model without any additional parameters. The outcome in comparison with other contemporary theoretical and experimental results is presented.Comment: Submitted to AIP for proceedings of International Workshop on Theoretical High Energy Physics held at IIT Roorkee, INDIA during 15-20 March, 200

    A new spectrophotometric method for the determination of Baygon in environment and biological samples

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    A sensitive, selective, cheaper and extractive spectrophotometeric method has been developed for the detection and determination of Baygon in fruits, vegetables, and grains is based on the coupling of their hydrolysation products with diazotized aniline. The dyes formed are measured at 450nm for Baygon after extraction in chloroform. Beer’s law is obeyed over concentration ranges of 0.8-5.0µg. The Molar absorptivity and Sandell’s sensitivity were found to be 9.7×105 L mol-1 cm-1 and 0.5×10-4 µg cm-2 respectively. The standard deviation and relative standard deviation were observed as ± 0.00336 and 0.0145% respectively. Various important analytical parameters were evaluated. The method was applied successfully to the determination of Baygon in water, grain, fruits, plant material and biological sample

    Low cost spectro photometric determination of paraquat in environmental and biological sample

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    An extractive, sensitive spectrophotometer method has been developed for the detection and determination of paraquat using glucose ( as easily available reducing agent ). Paraquat is reduced with glucose in alkaline medium to give a blue colored ion with an absorbance maxima at 610 nm. Beer’s law is obeyed in the range 0.5-5.0 µg of paraquat in 10ml of the final solution (ppm). The important analytical parameters and the optimum reaction conditions were evaluated. The method was applied successfully to the determination of paraquat in water, grain, plant material and biological sample

    Effects of Universal Extra Dimensions on Higgs signals at LHC

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    A major focus at the Large Hadron Collider (LHC) will be Higgs boson studies and it would be an interesting prospect to simultaneously probe for physics beyond the Standard Model (SM) in the Higgs signals. In this work we show as to what extent, the effects of Universal Extra Dimension (UED) can be isolated at the LHC through the Higgs signals. By doing a detailed study of the different uncertainties involved in the measurement of the rates for the process pp --> h --> gamma gamma we estimate the extent to which these uncertainties can mask the effects of the contributions coming from UED.Comment: 13 pages, LateX, Title changed, text and figures modified. Version to appear in IJMP

    Identifying the contributions of Universal Extra Dimensions in the Higgs sector at linear e+ e- colliders

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    We study the dilepton-dijet signal in the dominant Higgs production channel at a linear e+ e- collider. We estimate the effects of Universal Extra Dimension (UED) by a simple analysis of the cross-sections. The heavy Kaluza-Klein excitations of the Standard Model fields in UED can significantly alter the decay properties of the Higgs boson to loop-driven final states. We show that by taking a simple ratio between cross-sections of two different final states this difference can be very easily highlighted.Comment: Some parts of the text modified. 1 figure added. Version to appear in IJMP

    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.
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