24,910 research outputs found

    Geometric Phase, Bundle Classification, and Group Representation

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    The line bundles which arise in the holonomy interpretations of the geometric phase display curious similarities to those encountered in the statement of the Borel-Weil-Bott theorem of the representation theory. The remarkable relation of the geometric phase to the classification of complex line bundles provides the necessary tools for establishing the relevance of the Borel-Weil-Bott theorem to Berry's adiabatic phase. This enables one to define a set of topological charges for arbitrary compact connected semisimple dynamical Lie groups. In this paper, the problem of the determination of the parameter space of the Hamiltonian is also addressed. A simple topological argument is presented to indicate the relation between the Riemannian structure on the parameter space and Berry's connection. The results about the fibre bundles and group theory are used to introduce a procedure to reduce the problem of the non-adiabatic (geometric) phase to Berry's adiabatic phase for cranked Hamiltonians. Finally, the possible relevance of the topological charges of the geometric phase to those of the non-abelian monopoles is pointed out.Comment: 30 pages (LaTeX); UT-CR-12-9

    Tunneling and Non-Universality in Continuum Percolation Systems

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    The values obtained experimentally for the conductivity critical exponent in numerous percolation systems, in which the interparticle conduction is by tunnelling, were found to be in the range of t0t_0 and about t0+10t_0+10, where t0t_0 is the universal conductivity exponent. These latter values are however considerably smaller than those predicted by the available ``one dimensional"-like theory of tunneling-percolation. In this letter we show that this long-standing discrepancy can be resolved by considering the more realistic "three dimensional" model and the limited proximity to the percolation threshold in all the many available experimental studiesComment: 4 pages, 2 figure

    Penelitian Komunikasi Pendekatan Kualitatif Berbasis Teks

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    This article tries to explain the bridging of qualitative approach study. This article focuses on the bridging oriented to qualitative-research approach, especially qualitative text-based approach of Communication Research. The results show that as one of approaches, qualitative research approach is based on a postheriori-data principle belief. On the basis of data source criterion, qualitative research approach, -especially qualitative approach of research Communication- is divided into two groups. First, field-based qualitative approach and (second) text-based qualitative approaches. The text-based qualitative approach included text analysis model of Theo Van Leewin, Marxist analysis, etc

    Measurables of CPCP Violation in Bd→DCP0KSB_d\to D^0_{CP}K_S at a BB-meson Factory

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    In the context of the standard electroweak model, we emphasize that Bd→DCP0KSB_d\rightarrow D^0_{CP}K_S (DCP0D^0_{CP} denotes a CPCP eigenstate of D0D^0 or Dˉ0\bar{D}^0) can compete with Bd→π+π−B_d\rightarrow \pi^+\pi^- in studying CPCP violation and probing the Cabibbo-Kobayashi-Maskawa unitarity triangle. We discuss the measurables of direct and indirect CPCP asymmetries in Bd0B^0_d vs Bˉd0→DCP0KS\bar{B}^0_d\rightarrow D^0_{CP}K_S under the circumstance of an asymmetric BB-meson factory running on the Υ(4S)\Upsilon(4S) resonance, and show that both the weak and strong phases are experimentally determinable even in the presence of unknown final-state interactions.Comment: 6 Postscript pages, accepted for publication in IL Nuovo Cimento A as a "Note Brevi

    Nonlinear Friction Model for Passive Suspension System Identification and Effectiveness

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    To achieve a high level of performance, frictional effects have to be addressed by considering an accurate friction model, such that the resulting model faithfully simulates all observed types of friction behaviour. A nonlinear friction model is developed based on observed measurement results and dynamic system analysis. The model includes a stiction effect, a linear term (viscous friction), a nonlinear term (Coulomb friction) and an extra component at low velocities (Stribeck effect). During acceleration, the magnitude of the frictional force at just beyond zero velocity decreases due to the Stribeck effect, which means the influence of friction reduces from direct contact with bearings and body into the mixed lubrication mode at low velocity. This could be due to lubricant film behaviour. In respect of acceleration and deceleration when the direction changes for the mass body, friction almost depends on this direction, while the static frictional force exhibits springlike characteristics. However, friction is not determined by current velocity alone, it also depends on the history of the relative wheel and body velocities and movements, which are responsible for friction hysteresis behaviour

    Analisis Lalu Lintas Pada Jl. Abd. Dg. Sirua Akibat Pembangunan Jalan Alternatif Di Kota Makassar

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    Kota Makassar, sebagai pintu gerbang kawasan Indonesia Timur, perlu menyediakan segala sarana dan prasarana kota, termasuk jalan akses menuju ke pusat kota. Salah satu jalan alternatif yang akan dibangun di Makassar adalah Jl. Abd. Dg. Sirua, yang dapat menghubungkan pusat kota dengan daerah di bagian selatan. Dalam membangun jalan alternatif tersebut perlu diindentifikasi pengaruhnya terhadap kinerja sistem lalu lintas. Studi ini bertujuan memprakirakan dampak pembangunanan jalan alternatif terhadap kinerja sistem lalu lintas. Pengambilan data meliputi data primer, yang diperoleh melalui survey lapangan, dan data sekunder, yang diperoleh melalui survey institusional. Analisis dilakukan dengan membandingkan karakteristik lalu lintas sebelum dan sesuadah jalan alternatid beroperasi. Hasil yang diperoleh menunjukkan bahwa terjadi Perubahan karakteristik lalu lintas setelah jalan alternatif beroperasi., yaitu derajat kejenuhan berubah dari 0,67 menjadi 0,33, tingkat pelayanan dari C menjadi A, dan kecepatan lalu lintas dari 29 km/jam menjadi 48 km/jam. Kata

    Squeezed States and Hermite polynomials in a Complex Variable

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    Following the lines of the recent paper of J.-P. Gazeau and F. H. Szafraniec [J. Phys. A: Math. Theor. 44, 495201 (2011)], we construct here three types of coherent states, related to the Hermite polynomials in a complex variable which are orthogonal with respect to a non-rotationally invariant measure. We investigate relations between these coherent states and obtain the relationship between them and the squeezed states of quantum optics. We also obtain a second realization of the canonical coherent states in the Bargmann space of analytic functions, in terms of a squeezed basis. All this is done in the flavor of the classical approach of V. Bargmann [Commun. Pur. Appl. Math. 14, 187 (1961)].Comment: 15 page
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