1,223 research outputs found

    Stability maintenance at the grassroots: China’s weiwen apparatus as a form of conflict resolution

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    This working paper explores the history and potential of “stability maintenance” (weiwen) as a form of conflict resolution in China. Its emphasis on conflict resolution is novel. Previous examinations of the weiwen apparatus have concentrated on its political function, namely to manage resistance within society and maintain the authority of the party-state. This avenue of investigation has proved fruitful as a means of characterising the political motivation and the higher-level strategies involved in stability maintenance. Nonetheless, there remain significant conceptual and empirical gaps relating to how stability maintenance offices and processes actually function, particularly out of larger cities and at local levels. The research described in this paper aims to consider the effectiveness of stability maintenance as a part of the “market” for conflict resolution in local China, and to test the hypothesis that conflict resolution as facilitated by weiwen is the most pragmatic and effective means of actually resolving conflicts in the current Chinese political context, notwithstanding the closeness of the stability maintenance discourse to state authority and its relative distance from rule of law-based methods of dispute resolution..

    Stability analysis for laminar flow control, part 1

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    The basic equations for the stability analysis of flow over three dimensional swept wings are developed and numerical methods for their solution are surveyed. The equations for nonlinear stability analysis of three dimensional disturbances in compressible, three dimensional, nonparallel flows are given. Efficient and accurate numerical methods for the solution of the equations of stability theory were surveyed and analyzed

    Differences in five kilometer time trial performance during the recovery period after an ultramarathon race

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    Includes abstract.Includes bibliographical references.Athletes require an appropriate balance between training, competition stress and recovery to achieve maximal performance. Previous studies have shown that exercise induced muscle damage has a negative influence on endurance running performance, and that these negative effects may be mediated by an increased perception of effort. There is a lack of evidence regarding the effects of ultramarathon distance races on running performance, and the optimal duration of the recovery period before returning to competitive running. The aim of this study was to determine the changes in running performance during the recovery period after an ultramarathon race. The specific objectives were: (a) to determine differences in running performance between the experimental group (runners participating in the 2011 Comrades Marathon) and a control group (distance runners not taking part in the 2011 Comrades Marathon) during the recovery period after an ultramarathon race; (b) to determine the differences in muscle pain, heart rate and perception of effort during a 5 km time trial between groups and over time before, and during the recovery period after an ultramarathon race; and (c) to determine if there were any relationships between prior experience, training history, and running performance during the recovery period following an ultramarathon race

    Wave turbulence in Bose-Einstein condensates

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    The kinetics of nonequilibrium Bose-Einstein condensates are considered within the framework of the Gross-Pitaevskii equation. A systematic derivation is given for weak small-scale perturbations of a steady confined condensate state. This approach combines a wavepacket WKB description with the weak turbulence theory. The WKB theory derived in this paper describes the effect of the condensate on the short-wave excitations which appears to be different from a simple renormalization of the confining potential suggested in previous literature.Comment: 33 pages 2 figure

    Joint statistics of amplitudes and phases in Wave Turbulence

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    Random Phase Approximation (RPA) provides a very convenient tool to study the ensembles of weakly interacting waves, commonly called Wave Turbulence. In its traditional formulation, RPA assumes that phases of interacting waves are random quantities but it usually ignores randomness of their amplitudes. Recently, RPA was generalised in a way that takes into account the amplitude randomness and it was applied to study of the higher momenta and probability densities of wave amplitudes. However, to have a meaningful description of wave turbulence the RPA properties assumed for the initial fields must be proven to survive over the nonlinear evolution time, and such a proof is the main goal of the present paper. We derive an evolution equation for the full probability density function which contains the complete information about the joint statistics of all wave amplitudes and phases. We show that, for any initial statistics of the amplitudes, the phase factors remain statistically independent uniformly distributed variables. If in addition the initial amplitudes are also independent variables (but with arbitrary distributions) they will remain independent when considered in small sets which are much less than the total number of modes. However, if the size of a set is of order of the total number of modes then the joint probability density for this set is not factorisable into the product of one-mode probabilities. In the other words, the modes in such a set are involved in a ``collective'' (correlated) motion. We also study new type of correlators describing the phase statistics.Comment: 27 pages, uses feynmf packag

    Weakly Turbulent MHD Waves in Compressible Low-Beta Plasmas

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    In this Letter, weak turbulence theory is used to investigate interactions among Alfven waves and fast and slow magnetosonic waves in collisionless low-beta plasmas. The wave kinetic equations are derived from the equations of magnetohydrodynamics, and extra terms are then added to model collisionless damping. These equations are used to provide a quantitative description of a variety of nonlinear processes, including "parallel" and "perpendicular" energy cascade, energy transfer between wave types, "phase mixing," and the generation of back-scattered Alfven waves.Comment: Accepted, Physical Review Letter

    Derivation of Non-isotropic Phase Equations from a General Reaction-Diffusion Equation

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    A non-isotropic version of phase equations such as the Burgers equation, the K-dV-Burgers equation, the Kuramoto-Sivashinsky equation and the Benney equation in the three-dimensional space is systematically derived from a general reaction-diffusion system by means of the renormalization group method.Comment: 21pages,no figure

    Nonlinear 2+1--Dimensional Field Equations from Incomplete Lie Algebra Structures

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    We show that the nonlinear 2+1--dimensional Three--Wave Resonant Interaction equations, describing several important physical phenomena, can be generated starting from incomplete Lie algebras in the framework of multidimensional prolongation structures. We make use of an {\em ansatz} involving the structure equations of a principal prolongation connection induced by an admissible B\"acklund map.Comment: 9 page
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