955 research outputs found
Growing up: school, family and area influences on adolescents' later life chances
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
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
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
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
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
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
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
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
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
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