7,633 research outputs found

    On some non-conformal fractals

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    This paper presents a simple method of calculating the Hausdorff dimension for a class of non-conformal fractals

    The Correlation Between Spectral Index And Accretion Rate For AGN

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    In this paper, we present a correlation between the spectral index distribution (SED) and the dimensionless accretion rate defined as m˙=Lbol/LEdd\dot{m}={L_{bol}/L_{Edd}} for AGN. This quantity is used as a substitute of the physical accretion rate. We select 193 AGN with both broad Hα\alpha and broad Hβ\beta, and with absorption lines near MgIλ5175A˚\lambda5175\AA from SDSS DR4. We determine the spectral index and dimensionless accretion rate after correcting for both host galaxy contribution and internal reddening effects. A correlation is found between the optical spectral index and the dimensionless accretion rate for AGN, including low luminosity AGN (LHα<1041erg⋅s−1L_{H\alpha}<10^{41}{\rm erg\cdot s^{-1}} sometimes called "dwarf AGN" (Ho et al. 1997)). The existence of this correlation provides an independent method to estimate the central BH masses for all types of AGN. We also find that there is a different correlation between the spectral index and the BH masses for normal AGN and low luminosity AGN, which is perhaps due to the different accretion modes in these two types of nuclei. This in turn may lead to the different correlations between BH masses and optical continuum luminosity reported previously (Zhang et al. 2007a), which invalidates the application of the empirical relationship found by Kaspi et al. (2000, 2005) to low luminosity AGN in order to determine their BLR sizes.Comment: 10 pages, 7 figures, accepted for publication in MNRA

    Long-Term Human Video Generation of Multiple Futures Using Poses

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    Predicting future human behavior from an input human video is a useful task for applications such as autonomous driving and robotics. While most previous works predict a single future, multiple futures with different behavior can potentially occur. Moreover, if the predicted future is too short (e.g., less than one second), it may not be fully usable by a human or other systems. In this paper, we propose a novel method for future human pose prediction capable of predicting multiple long-term futures. This makes the predictions more suitable for real applications. Also, from the input video and the predicted human behavior, we generate future videos. First, from an input human video, we generate sequences of future human poses (i.e., the image coordinates of their body-joints) via adversarial learning. Adversarial learning suffers from mode collapse, which makes it difficult to generate a variety of multiple poses. We solve this problem by utilizing two additional inputs to the generator to make the outputs diverse, namely, a latent code (to reflect various behaviors) and an attraction point (to reflect various trajectories). In addition, we generate long-term future human poses using a novel approach based on unidimensional convolutional neural networks. Last, we generate an output video based on the generated poses for visualization. We evaluate the generated future poses and videos using three criteria (i.e., realism, diversity and accuracy), and show that our proposed method outperforms other state-of-the-art works

    Modified Bennett-Brassard 1984 Quantum Key Distribution With Two-way Classical Communications

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    The quantum key distribution protocol without public announcement of bases is equipped with a two-way classical communication symmetric entanglement purification protocol. This modified key distribution protocol is unconditionally secure and has a higher tolerable error rate of 20%, which is higher than previous scheme without public announcement of bases.Comment: 5 pages. To appear in Physical Review

    Spectroscopy of q3qˉ3\rm{q}^3\bar{\rm{q}}^3-States in Quark Model and Baryon-Antibaryon Enhancements

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    We study the mass spectrum of the q3qˉ3\rm{q}^3\bar{\rm{q}}^3 mesons both from the quark model with triquark correlations and from common quark model with colormagnetic interactions and with relative S-waves between quarks. Two cluster configurations (q3)−(qˉ3)(\rm{q}^3)-(\bar{\rm{q}}^3) and (q2qˉ)−(qqˉ2)(\rm{q}^2\bar{\rm{q}})-(\rm{q}\bar{\rm{q}}^2) are considered. In the spectrum we find rather stable states which have the same quantum number with particle resonances which are corresponding to the ppˉp\bar{p} enhancement, pΛˉp\bar{\Lambda} enhancement and ΛΛˉ\Lambda\bar{\Lambda} enhancement with spin-0\mathbf{0} or 1\mathbf{1}. This imply these enhancements are NOT experimental artifacts. The color-spin-flavor structures of ppˉp\bar{p}, pΛˉp\bar{\Lambda}, and ΛΛˉ\Lambda\bar{\Lambda} enhancements are revealed. The existence of spin-1\mathbf{1} ΛΛˉ,pΛˉ,ppˉ\Lambda\bar{\Lambda}, p\bar{\Lambda}, p\bar{p} enhancements is predicted.Comment: 45 pages, 5 figure
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