8,191 research outputs found

    [Review of] Jamaica Kincaid. Annie John

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    Annie John, even though set in the West Indies and about a black Caribbean girl, is a work whose universally felt experience goes beyond allowing the novel to be neatly categorized as a piece of ethnic or women\u27s writing. Born on Antigua, the island in which she sets the novel, Jamaica Kincaid catches many of the ways of being peculiar to this place. Maybe it is because Kincaid makes the setting home that we as readers find it so easy to slip into the story

    An EPROM-based function generator

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    A circuit is described to produce arbitrary time-dependent voltage functions derived from digital information stored in EPROMs. While this circuit is designed to be used as a modulator of the microwave pump source or a solid state low noise maser, it can be readily adapted for other applications

    Goldstone Theorem in the Gaussian Functional Approximation to the Scalar ϕ4\phi^{4} Theory

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    We verify the Goldstone theorem in the Gaussian functional approximation to the ϕ4\phi^{4} theory with internal O(2) symmetry. We do so by reformulating the Gaussian approximation in terms of Schwinger-Dyson equations from which an explicit demonstration of the Goldstone theorem follows directly.Comment: 11 page

    The addition of algebraic turbulence modeling to program LAURA

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    The Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) is modified to allow the calculation of turbulent flows. This is accomplished using the Cebeci-Smith and Baldwin-Lomax eddy-viscosity models in conjunction with the thin-layer Navier-Stokes options of the program. Turbulent calculations can be performed for both perfect-gas and equilibrium flows. However, a requirement of the models is that the flow be attached. It is seen that for slender bodies, adequate resolution of the boundary-layer gradients may require more cells in the normal direction than a laminar solution, even when grid stretching is employed. Results for axisymmetric and three-dimensional flows are presented. Comparison with experimental data and other numerical results reveal generally good agreement, except in the regions of detached flow

    Resonantly Interacting Fermions In a Box

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    We use two fundamental theoretical frameworks to study the finite-size (shell) properties of the unitary gas in a periodic box: 1) an ab initio Quantum Monte Carlo (QMC) calculation for boxes containing 4 to 130 particles provides a precise and complete characterization of the finite-size behavior, and 2) a new Density Functional Theory (DFT) fully encapsulates these effects. The DFT predicts vanishing shell structure for systems comprising more than 50 particles, and allows us to extrapolate the QMC results to the thermodynamic limit, providing the tightest bound to date on the ground-state energy of the unitary gas: \xi_S <= 0.383(1). We also apply the new functional to few-particle harmonically trapped systems, comparing with previous calculations.Comment: Updated to correspond with published version: 4+ pages, 2 figures, 2 tables, Palatino and Euler font

    Are We All in This Together? Exploring the Impact of Austerity on Access to Justice for Women

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    This article examines the impact of austerity on access to justice for women. It attempts to engage seriously with the key concepts of austerity and access to justice, before arguing that the impact of austerity on access to justice has been especially grave for women. This is because women have borne the brunt of the funding cuts both in terms of justice-specific policies and public sector spending more broadly. As there is a strong link between financial hardship and deficient access to justice, the latter is essential in illustrating the ramifications of austerity for access to justice in full. The article goes on to highlight that for victims of domestic violence, these ramifications amount to a violation of the United Kingdom’s international obligations under the European Convention on Human Rights and the United Nations Convention for the Elimination of Discrimination and Violence Against Women

    A wide bandwidth free-electron laser with mode locking using current modulation

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    A new scheme for mode locking a free-electron laser (FEL) amplifier is proposed based on electron beam current modulation. It is found that certain properties of the original concept (Thompson and McNeil 2008 Phys. Rev. Lett. 100 203901), based on the energy modulation of electrons, are improved, including the spectral brightness of the source and the purity of the series of short pulses. Numerical comparisons are made between the new and old schemes and between a mode-locked FEL and a self-amplified spontaneous emission FEL. Illustrative examples using a hypothetical mode-locked FEL amplifier are provided. The ability to generate intense coherent radiation with a large bandwidth is demonstrated

    From Default Probabilities To Credit Spreads: Credit Risk Models Do Explain Market Prices

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    Credit risk models like Moody’s KMV are now well established in the market and give bond managers reliable estimates of default probabilities for individual firms. Until now it has been hard to relate those probabilities to the actual credit spreads observed on the market for corporate bonds. Inspired by the existence of scaling laws in financial markets by Dacorogna et al. (2001) and Di Matteo et al. (2005) deviating from the Gaussian behavior, we develop a model that quantitatively links those default probabilities to credit spreads (market prices). The main input quantities to this study are merely industry yield data of different times to maturity and expected default frequencies (EDFs) of Moody’s KMV. The empirical results of this paper clearly indicate that the model can be used to calculate approximate credit spreads (market prices) from EDFs, independent of the time to maturity and the industry sector under consideration. Moreover, the model is effective in an out-of-sample setting, it produces consistent results on the European bond market where data are scarce and can be adequately used to approximate credit spreads on the corporate level.

    Freezing line of the Lennard-Jones fluid: a Phase Switch Monte Carlo study

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    We report a Phase Switch Monte Carlo (PSMC) method study of the freezing line of the Lennard-Jones (LJ) fluid. Our work generalizes to soft potentials the original application of the method to hard sphere freezing, and builds on a previous PSMC study of the LJ system by Errington (J. Chem. Phys. {\bf 120}, 3130 (2004)). The latter work is extended by tracing a large section of the Lennard-Jones freezing curve, the results for which we compare to a previous Gibbs-Duhem integration study. Additionally we provide new background regarding the statistical mechanical basis of the PSMC method and extensive implementation details.Comment: 18 pages, 6 figure

    Objective measurement of habitual sedentary behavior in pre-school children: comparison of activPAL with actigraph monitors

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    The Actigraph is well established for measurement of both physical activity and sedentary behavior in children. The activPAL is being used increasingly in children, though with no published evidence on its use in free-living children to date. The present study compared the two monitors in preschool children. Children (n 23) wore both monitors simultaneously during waking hours for 5.6d and 10h/d. Daily mean percentage of time sedentary (nontranslocation of the trunk) was 74.6 (SD 6.8) for the Actigraph and 78.9 (SD 4.3) for activPAL. Daily mean percentage of time physically active (light intensity physical activity plus MVPA) was 25.4 (SD 6.8) for the Actigraph and 21.1 (SD 4.3) for the activPAL. Bland-Altman tests and paired t tests suggested small but statistically significant differences between the two monitors. Actigraph and activPAL estimates of sedentary behaviour and physical activity in young children are similar at a group level
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