870 research outputs found

    General transformation of alpha cluster model wave function to jj-coupling shell model in various 4N nuclei

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    The antisymmetrized quasi-cluster model (AQCM) is a method to describe a transition from the alpha-cluster wave function to the jj-coupling shell model wave function. In this model, the cluster-shell transition is characterized by only two parameters; R representing the distance between alpha clusters and Lambda describing the breaking of alpha clusters, and the contribution of the spin-orbit interaction, very important in the jj-coupling shell model, can be taken into account starting with the alpha cluster model wave function. In this article we show the generality of AQCM by extending the application to heavier region; various 4N nuclei from 4He to 52Fe. We show and compare the energy curves for the alpha+40Ca cluster configuration calculated with and without alpha breaking effect in 44Ti

    A novel method for subjective picture quality assessment and further studies of HDTV formats

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ IEEE 2008.This paper proposes a novel method for the assessment of picture quality, called triple stimulus continuous evaluation scale (TSCES), to allow the direct comparison of different HDTV formats. The method uses an upper picture quality anchor and a lower picture quality anchor with defined impairments. The HDTV format under test is evaluated in a subjective comparison with the upper and lower anchors. The method utilizes three displays in a particular vertical arrangement. In an initial series of tests with the novel method, the HDTV formats 1080p/50,1080i/25, and 720p/50 were compared at various bit-rates and with seven different content types on three identical 1920 times 1080 pixel displays. It was found that the new method provided stable and consistent results. The method was tested with 1080p/50,1080i/25, and 720p/50 HDTV images that had been coded with H.264/AVC High profile. The result of the assessment was that the progressive HDTV formats found higher appreciation by the assessors than the interlaced HDTV format. A system chain proposal is given for future media production and delivery to take advantage of this outcome. Recommendations for future research conclude the paper

    Symplectic structure and monopole strength in 12C

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    The relation between the monopole transition strength and existence of cluster structure in the excited states is discussed based on an algebraic cluster model. The structure of 12^{12}C is studied with a 3α\alpha model, and the wave function for the relative motions between α\alpha clusters are described by the symplectic algebra Sp(2,R)zSp(2,R)_z, which corresponds to the linear combinations of SU(3)SU(3) states with different multiplicities. Introducing Sp(2,R)zSp(2,R)_z algebra works well for reducing the number of the basis states, and it is also shown that states connected by the strong monopole transition are classified by a quantum number Λ\Lambda of the Sp(2,R)zSp(2,R)_z algebra.Comment: Phys. Rev. C in pres

    Studies on the bit rate requirements for a HDTV format with 1920 timestimes 1080 pixel resolution, progressive scanning at 50 Hz frame rate targeting large flat panel displays

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    This paper considers the potential for an HDTV delivery format with 1920 times 1080 pixels progressive scanning and 50 frames per second in broadcast applications. The paper discusses the difficulties in characterizing the display to be assumed for reception. It elaborates on the required bit rate of the 1080p/50 format when critical content is coded in MPEG-4 H.264 AVC Part 10 and subjectively viewed on a large, flat panel display with 1920 times 1080 pixel resolution. The paper describes the initial subjective quality evaluations that have been made in these conditions. The results of these initial tests suggest that the required bit-rate for a 1080p/50 HDTV signal in emission could be kept equal or lower than that of 2nd generation HDTV formats, to achieve equal or better image qualit