18,644 research outputs found

    China Since Tiananmen: The Labor Movement

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    [Excerpt] The twenty years since 1989 have brought two major developments in worker activism. First, whereas workers were part of the mass uprising in the Tiananmen movement, albeit as subordinate partners to the students, labor activism since then has been almost entirely confined to the working class. While the ranks of aggrieved workers have proliferated (expanding from workers in the state-owned sector to include migrant workers) and the forms and incidents of labor activism have multiplied, there is hardly any sign of mobilization that transcends class or regional lines. Second, we observe that a long-term decline in worker power at the point of production – power that was previously institutionalized in skill hierarchies, union representation, democratic management, permanent or long-term employment, and other conditions of service constitutive of the socialist social contract - is going on even as workers gain more power (at least on paper) outside the workplace. New labor laws have broadened workers\u27 rights and expanded administrative and judicial channels for resolving labor conflicts. These legal and bureaucratic procedures have atomized and depoliticized labor activism even as they have engendered and intensified mobilization outside official limits

    Is Lavelle-McMullan transformation a really new symmetry in QED?

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    Lavelle-McMullan symmetry of QED is examined at classical and quantum levels. It is shown that Lavelle-McMullan symmetry does not give any new non-trivial information in QED by examining the Ward-Takahashi identities. Being inspired by the examination of Ward-Takahashi identity, we construct the generalized non-local and non-covariant symmetries of QED.Comment: LATEX, 9 pages, two figures generated by Feynma

    Dynamics of rapidly rotating Bose-Einstein condensates in a harmonic plus quartic trap

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    A two-dimensional rapidly rotating Bose-Einstein condensate in a harmonic plus quartic trap is expected to have unusual vortex states that do not occur in a pure harmonic trap. At a critical rotation speed Ωh\Omega_h, a central hole appears in the condensate, and at some faster rotation speed Ωg\Omega_g, the system undergoes a transition to a giant vortex state with pure irrotational flow. Using a time-dependent variational analysis, we study the behavior of an annular condensate with a single concentric ring of vortices. The transition to a giant vortex state is investigated by comparing the energy of the two equilibrium states (the ring of vortices and the giant vortex) and also by studying the dynamical stability of small excitation modes of the ring of vortices.Comment: 12pages, 4figure

    Effect of dissipation on the decay-rate phase transition

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    A general condition for sharp transition of decay rate from quantum to thermal regimes is derived in dissipative tunneling models when position dependent mass is involved. It is shown that the effect of dissipation in general changes the order of the phase transition. Especially, for the models with constant mass the Ohmic dissipation enlarges the range of parameters for first-order phase transitions. In the case of second-order phase transition the Ohmic dissipation suppresses the decay rate near the transition temperature(T_c). For the super-Ohmic case the dissipation yields an opposite effects to the Ohmic dissipation within exponential approximation.Comment: 12 pages, 3figure

    An algorithm for series expansions based on hierarchical rate equations

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    We propose a computational method to obtain series expansions in powers of time for general dynamical systems described by a set of hierarchical rate equations. The method is generally applicable to problems in both equilibrium and nonequilibrium statistical mechanics such as random sequential adsorption, diffusion-reaction dynamics, and Ising dynamics. New result of random sequential adsorption of dimers on a square lattice is presented.Comment: LaTeX, 9 pages including 1 figur

    The informativeness of stochastic frontier and programming frontier efficiency scores: Cost efficiency and other measures of bank holding company performance

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    This paper examines the properties of the X-inefficiencies in U.S. bank holding companies derived from both stochastic and linear programming frontiers. This examination allows the robustness of results across methods to be compared. While we find that calculated programming inefficiency scores are two to three times larger than those estimated using a stochastic frontier, the patterns of the scores across banks and time are similar, and there is a relatively high correlation of the rankings of banks' efficiencies under the two methods. However, when we examine the "informativeness" of the efficiency measured by the two different techniques, we find some large differences. We find evidence that the stochastic frontier scores are more closely related to risk-taking behavior, managerial competence, and bank stock returns. Based on these findings, we conclude that while both methods produce informative efficiency scores, for this data set decision makers should put more weight on the stochastic frontier efficiency estimates.Bank holding companies ; Banks and banking - Costs
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