16,312 research outputs found

    Crowdsourcing a Word-Emotion Association Lexicon

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    Even though considerable attention has been given to the polarity of words (positive and negative) and the creation of large polarity lexicons, research in emotion analysis has had to rely on limited and small emotion lexicons. In this paper we show how the combined strength and wisdom of the crowds can be used to generate a large, high-quality, word-emotion and word-polarity association lexicon quickly and inexpensively. We enumerate the challenges in emotion annotation in a crowdsourcing scenario and propose solutions to address them. Most notably, in addition to questions about emotions associated with terms, we show how the inclusion of a word choice question can discourage malicious data entry, help identify instances where the annotator may not be familiar with the target term (allowing us to reject such annotations), and help obtain annotations at sense level (rather than at word level). We conducted experiments on how to formulate the emotion-annotation questions, and show that asking if a term is associated with an emotion leads to markedly higher inter-annotator agreement than that obtained by asking if a term evokes an emotion

    Energy of Stable Half-Quantum Vortex in Equal-Spin-Pairing

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    In the triplet equal-spin-pairing states of both 3He-A phase and Sr2RuO4 superconductor, existence of Half-Quantum Vortices HQVs are possible. The vortices carry half-integer multiples of magnetic quantum flux (hc/2e). To obtain equilibrium condition for such systems, one has to take into account not only weak interaction energy but also effects of Landau Fermi liquid. Our method is based on the explanation of the HQV in terms of a BCS-like wave function with a spin-dependent boots. We have considered l=2 order effects of the Landau Fermi liquid. We have shown that the effects of Landau Fermi liquid interaction with l=2 are negligible. In stable HQV, an effective Zeeman field exists. In the thermodynamic stability state, the effective Zeeman field produces a non-zero spin polarization in addition to the polarization of external magnetic field

    Quotient graphs for power graphs

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    In a previous paper of the first author a procedure was developed for counting the components of a graph through the knowledge of the components of its quotient graphs. We apply here that procedure to the proper power graph P0(G)\mathcal{P}_0(G) of a finite group GG, finding a formula for the number c(P0(G))c(\mathcal{P}_0(G)) of its components which is particularly illuminative when G≤SnG\leq S_n is a fusion controlled permutation group. We make use of the proper quotient power graph P~0(G)\widetilde{\mathcal{P}}_0(G), the proper order graph O0(G)\mathcal{O}_0(G) and the proper type graph T0(G)\mathcal{T}_0(G). We show that all those graphs are quotient of P0(G)\mathcal{P}_0(G) and demonstrate a strong link between them dealing with G=SnG=S_n. We find simultaneously c(P0(Sn))c(\mathcal{P}_0(S_n)) as well as the number of components of P~0(Sn)\widetilde{\mathcal{P}}_0(S_n), O0(Sn)\mathcal{O}_0(S_n) and T0(Sn)\mathcal{T}_0(S_n)

    Front speed enhancement by incompressible flows in three or higher dimensions

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    We study, in dimensions N≥3N\geq 3, the family of first integrals of an incompressible flow: these are Hloc1H^{1}_{loc} functions whose level surfaces are tangent to the streamlines of the advective incompressible field. One main motivation for this study comes from earlier results proving that the existence of nontrivial first integrals of an incompressible flow qq is the main key that leads to a "linear speed up" by a large advection of pulsating traveling fronts solving a reaction-advection-diffusion equation in a periodic heterogeneous framework. The family of first integrals is not well understood in dimensions N≥3N\geq3 due to the randomness of the trajectories of qq and this is in contrast with the case N=2. By looking at the domain of propagation as a union of different components produced by the advective field, we provide more information about first integrals and we give a class of incompressible flows which exhibit `ergodic components' of positive Lebesgue measure (hence are not shear flows) and which, under certain sharp geometric conditions, speed up the KPP fronts linearly with respect to the large amplitude. In the proofs, we establish a link between incompressibility, ergodicity, first integrals, and the dimension to give a sharp condition about the asymptotic behavior of the minimal KPP speed in terms the configuration of ergodic components.Comment: 34 pages, 3 figure

    Resolving the fine-scale structure in turbulent Rayleigh-Benard convection

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    We present high-resolution direct numerical simulation studies of turbulent Rayleigh-Benard convection in a closed cylindrical cell with an aspect ratio of one. The focus of our analysis is on the finest scales of convective turbulence, in particular the statistics of the kinetic energy and thermal dissipation rates in the bulk and the whole cell. The fluctuations of the energy dissipation field can directly be translated into a fluctuating local dissipation scale which is found to develop ever finer fluctuations with increasing Rayleigh number. The range of these scales as well as the probability of high-amplitude dissipation events decreases with increasing Prandtl number. In addition, we examine the joint statistics of the two dissipation fields and the consequences of high-amplitude events. We also have investigated the convergence properties of our spectral element method and have found that both dissipation fields are very sensitive to insufficient resolution. We demonstrate that global transport properties, such as the Nusselt number, and the energy balances are partly insensitive to insufficient resolution and yield correct results even when the dissipation fields are under-resolved. Our present numerical framework is also compared with high-resolution simulations which use a finite difference method. For most of the compared quantities the agreement is found to be satisfactory.Comment: 33 pages, 24 figure
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