955 research outputs found

    Growing up: school, family and area influences on adolescents' later life chances

    Get PDF
    This paper explores the links between school, family and area background influences during adolescence and later adult economic outcomes. The empirical analysis is based on data covering the period 1979 to 1996, drawn from the 1979 US National Longitudinal Survey of Youth. For a sample of individuals aged 14 to 19 in 1979, estimates are produced of the impact of family, school and local area when growing up, on earnings capacity and poverty risk once they reach adulthood

    Growing Up: School, family and area influences on adolescents later life chances

    Get PDF
    This paper explores the links between school, family and area background influences during adolescence and later adult economic outcomes. The empirical analysis is based on data covering the period 1979 to 1996, drawn from the 1979 US National Longitudinal Survey of Youth. For a sample of individuals aged 14 to 19 in 1979, estimates are produced of the impact of family, school and local area when growing up, on earnings capacity and poverty risk once they reach adulthood.family background, poverty, wages, impact of schooling, area effects

    Why rising tides dont lift all boats? An explanation of the relationship between poverty and unemployment in Britain

    Get PDF
    Abstract: This paper is motivated by the lack of any obvious relationship between aggregate poverty and unemployment in Great Britain. We derive a framework based on individuals' risks of unemployment and poverty, and how these vary over the economic cycle. Analysing the British Household Panel Survey for 1991-96, we are able to square the micro evidence - that unemployment matters for poverty - with the macro picture - that there's no strong link. We then go on to identify which household and individual characteristics are associated with whether an individual's poverty risk is vulnerable to the economic cycle.Poverty, unemployment, economic cycle

    Measuring Income Risk

    Get PDF
    We provide a critique of the methods that have been used to derive measures of income risk and draw attention to the importance of demographic factors as a source of income risk. We also propose new measures of the contribution to total income risk of demographic and labour market factors. Empirical evidence supporting our arguments is provided using data from the British Household Survey.

    Measuring Income Risk

    Get PDF
    We provide a critique of the methods that have been used to derive measures of income risk and draw attention to the importance of demographic factors as a source of income risk. We also propose new measures of the contribution to total income risk of demographic and labour market factors. Empirical evidence supporting our arguments is provided using data from the British Household Survey.Income risk, demographics, panel data

    Viscous and Resistive Effects on the MRI with a Net Toroidal Field

    Full text link
    Resistivity and viscosity have a significant role in establishing the energy levels in turbulence driven by the magnetorotational instability (MRI) in local astrophysical disk models. This study uses the Athena code to characterize the effects of a constant shear viscosity \nu and Ohmic resistivity \eta in unstratified shearing box simulations with a net toroidal magnetic flux. A previous study of shearing boxes with zero net magnetic field performed with the ZEUS code found that turbulence dies out for values of the magnetic Prandtl number, P_m = \nu/\eta, below P_m \sim 1; for P_m \gtrsim 1, time- and volume-averaged stress levels increase with P_m. We repeat these experiments with Athena and obtain consistent results. Next, the influence of viscosity and resistivity on the toroidal field MRI is investigated both for linear growth and for fully-developed turbulence. In the linear regime, a sufficiently large \nu or \eta can prevent MRI growth; P_m itself has little direct influence on growth from linear perturbations. By applying a range of values for \nu and \eta to an initial state consisting of fully developed turbulence in the presence of a background toroidal field, we investigate their effects in the fully nonlinear system. Here, increased viscosity enhances the turbulence, and the turbulence decays only if the resistivity is above a critical value; turbulence can be sustained even when P_m < 1, in contrast to the zero net field model. While we find preliminary evidence that the stress converges to a small range of values when \nu and \eta become small enough, the influence of dissipation terms on MRI-driven turbulence for relatively large \eta and \nu is significant, independent of field geometry.Comment: Accepted to ApJ; version 2 - minor changes following review; 35 pages (preprint format), 10 figure

    Coherent controllers for optical-feedback cooling of quantum oscillators

    Full text link
    We study the cooling performance of optical-feedback controllers for open optical and mechanical resonators in the Linear Quadratic Gaussian setting of stochastic control theory. We utilize analysis and numerical optimization of closed-loop models based on quantum stochastic differential equations to show that coherent control schemes, where we embed the resonator in an interferometer to achieve all-optical feedback, can outperform optimal measurement-based feedback control schemes in the quantum regime of low steady-state excitation number. These performance gains are attributed to the coherent controller's ability to simultaneously process both quadratures of an optical probe field without measurement or loss of fidelity, and may guide the design of coherent feedback schemes for more general problems of robust nonlinear and robust control.Comment: 15 pages, 20 figures. Submitted to Physical Review X. Follow-up paper to arXiv:1206.082

    Measurement-based approach to entanglement generation in coupled quantum dots

    Get PDF
    Measurements provide a novel mechanism for generating the entanglement resource necessary for performing scalable quantum computation. Recently, we proposed a method for performing parity measurements in a coupled quantum dot system. In this paper we generalise this scheme and perform a comprehensive analytic and numerical study of environmental factors. We calculate the effects of possible error sources including non-ideal photon detectors, ineffective spin-selective excitation and dot distinguishability (both spatial and spectral). Furthermore, we present an experimental approach for verifying the success of the parity measurement

    Dressed, noise- or disorder- resilient optical lattices

    Full text link
    External noise is inherent in any quantum system, and can have especially strong effects for systems exhibiting sensitive many-body phenomena. We show how a dressed lattice scheme can provide control over certain types of noise for atomic quantum gases in the lowest band of an optical lattice, removing the effects of lattice amplitude noise to first order for particular choices of the dressing field parameters. We investigate the non-equilibrium many-body dynamics for bosons and fermions induced by noise away from this parameter regime, and also show how the same technique can be used to reduce spatial disorder in projected lattice potentials.Comment: 4+ Pages, 4 Figure
    • 

    corecore