548 research outputs found

    El perfil de la pobreza en Montevideo 1983 - 1992

    Get PDF
    In this paper, time series on the extent of poverty in Montevideo (1983-92) are derived and analysed using different measures and approaches in the definition of the poverty line. The results show that the picture of how poverty has developed is much affected by the use of and absolute or relative poverty line. Meanwhile relative poverty is quite stable, the proportion of the population under a poverty line indicating a constant living standard is closely related to GDP. The measures that were used are descomposable. The results show that young persons, especially children are poverty prone and that a high education of the household head means a low risk of becoming poor.

    Journal for the history of analytical philosophy: Gilbert Ryle: intelligence, practice, skill, v. 5, no. 5

    Get PDF
    Special issue on Gilbert Ryle edited by Juliet Floyd and Lydia Patton. Articles: "Volume Introduction: Gilbert Ryle on Propositions, Propositional Attitudes, and Theoretical Knowledge" by Julia Tanney; "Ryle’s “Intellectualist Legend” in Historical Context" by Michael Kremer; "Skill, Drill, and Intelligent Performance: Ryle and Intellectualism" by Stina Bäckström and Martin Gustafsson; "Ryle on the Explanatory Role of Knowledge How"by Will Small.https://jhaponline.org/jhap/issue/view/319Published versio

    Algorithms for Infeasible Path Calculation

    Get PDF
    Static Worst-Case Execution Time (WCET) analysis is a technique to derive upper bounds for the execution times of programs. Such bounds are crucial when designing and verifying real-time systems. One key component in static WCET analysis is to derive flow information, such as loop bounds and infeasible paths for the analysed program. Such flow information can be provided as either as annotations by the user, can be automatically calculated by a flow analysis, or by a combination of both. To make the analysis as simple, automatic and safe as possible, this flow information should be calculated automatically with no or very limited user interaction. In this paper we present three novel algorithms to calculate infeasible paths. The algorithms are all designed to be simple and efficient, both in terms of generated flow facts and in analysis running time. The algorithms have been implemented and tested for a set of WCET benchmarks programs

    Multifluid magnetohydrodynamic turbulent decay

    Get PDF
    It is generally believed that turbulence has a significant impact on the dynamics and evolution of molecular clouds and the star formation which occurs within them. Non-ideal magnetohydrodynamic effects are known to influence the nature of this turbulence. We present the results of a suite of 512-cubed resolution simulations of the decay of initially super-Alfvenic and supersonic fully multifluid MHD turbulence. We find that ambipolar diffusion increases the rate of decay of the turbulence while the Hall effect has virtually no impact. The decay of the kinetic energy can be fitted as a power-law in time and the exponent is found to be -1.34 for fully multifluid MHD turbulence. The power spectra of density, velocity and magnetic field are all steepened significantly by the inclusion of non-ideal terms. The dominant reason for this steepening is ambipolar diffusion with the Hall effect again playing a minimal role except at short length scales where it creates extra structure in the magnetic field. Interestingly we find that, at least at these resolutions, the majority of the physics of multifluid turbulence can be captured by simply introducing fixed (in time and space) resistive terms into the induction equation without the need for a full multifluid MHD treatment. The velocity dispersion is also examined and, in common with previously published results, it is found not to be power-law in nature.Comment: 16 pages, 15 figures, Accepted for publication in Ap

    3D simulations of Einstein's equations: symmetric hyperbolicity, live gauges and dynamic control of the constraints

    Full text link
    We present three-dimensional simulations of Einstein equations implementing a symmetric hyperbolic system of equations with dynamical lapse. The numerical implementation makes use of techniques that guarantee linear numerical stability for the associated initial-boundary value problem. The code is first tested with a gauge wave solution, where rather larger amplitudes and for significantly longer times are obtained with respect to other state of the art implementations. Additionally, by minimizing a suitably defined energy for the constraints in terms of free constraint-functions in the formulation one can dynamically single out preferred values of these functions for the problem at hand. We apply the technique to fully three-dimensional simulations of a stationary black hole spacetime with excision of the singularity, considerably extending the lifetime of the simulations.Comment: 21 pages. To appear in PR

    Simulating binary neutron stars: dynamics and gravitational waves

    Full text link
    We model two mergers of orbiting binary neutron stars, the first forming a black hole and the second a differentially rotating neutron star. We extract gravitational waveforms in the wave zone. Comparisons to a post-Newtonian analysis allow us to compute the orbital kinematics, including trajectories and orbital eccentricities. We verify our code by evolving single stars and extracting radial perturbative modes, which compare very well to results from perturbation theory. The Einstein equations are solved in a first order reduction of the generalized harmonic formulation, and the fluid equations are solved using a modified convex essentially non-oscillatory method. All calculations are done in three spatial dimensions without symmetry assumptions. We use the \had computational infrastructure for distributed adaptive mesh refinement.Comment: 14 pages, 16 figures. Added one figure from previous version; corrected typo

    Constraint preserving boundary conditions for the Ideal Newtonian MHD equations

    Full text link
    We study and develop constraint preserving boundary conditions for the Newtonian magnetohydrodynamic equations and analyze the behavior of the numerical solution upon considering different possible options.Comment: uses elsart styl

    Boundary conditions for hyperbolic formulations of the Einstein equations

    Get PDF
    In regards to the initial-boundary value problem of the Einstein equations, we argue that the projection of the Einstein equations along the normal to the boundary yields necessary and appropriate boundary conditions for a wide class of equivalent formulations. We explicitly show that this is so for the Einstein-Christoffel formulation of the Einstein equations in the case of spherical symmetry.Comment: 15 pages; text added and typesetting errors corrected; to appear in Classical and Quantum Gravit
    corecore