56,427 research outputs found
Gender differences in paid and unpaid work: findings from a New Zealand birth cohort
This study uses data from a birth cohort of New Zealand-born 30-year-olds to examine gender differences in time use and satisfaction with time use.
The specific aims of the study are:
to examine gender difference in time spent in paid employment and unpaid work;
to examine the extent to which males and females are satisfied with their time use
Robust randomized benchmarking of quantum processes
We describe a simple randomized benchmarking protocol for quantum information
processors and obtain a sequence of models for the observable fidelity decay as
a function of a perturbative expansion of the errors. We are able to prove that
the protocol provides an efficient and reliable estimate of an average
error-rate for a set operations (gates) under a general noise model that allows
for both time and gate-dependent errors. We determine the conditions under
which this estimate remains valid and illustrate the protocol through numerical
examples.Comment: 4+ pages, 1 figure, and 1 tabl
Neptune's Migration into a Stirred-Up Kuiper Belt: A Detailed Comparison of Simulations to Observations
Nbody simulations are used to examine the consequences of Neptune's outward
migration into the Kuiper Belt, with the simulated endstates being compared
rigorously and quantitatively to the observations. These simulations confirm
the findings of Chiang et al. (2003), who showed that Neptune's migration into
a previously stirred-up Kuiper Belt can account for the Kuiper Belt Objects
(KBOs) known to librate at Neptune's 5:2 resonance. We also find that capture
is possible at many other weak, high-order mean motion resonances, such as the
11:6, 13:7, 13:6, 9:4, 7:3, 12:5, 8:3, 3:1, 7:2, and the 4:1. The more distant
of these resonances, such as the 9:4, 7:3, 5:2, and the 3:1, can also capture
particles in stable, eccentric orbits beyond 50 AU, in the region of phase
space conventionally known as the Scattered Disk. Indeed, 90% of the simulated
particles that persist over the age of the Solar System in the so-called
Scattered Disk zone never had a close encounter with Neptune, but instead were
promoted into these eccentric orbits by Neptune's resonances during the
migration epoch. This indicates that the observed Scattered Disk might not be
so scattered. This model also produced only a handful of Centaurs, all of which
originated at Neptune's mean motion resonances in the Kuiper Belt. We also
report estimates of the abundances and masses of the Belt's various
subpopulations (e.g., the resonant KBOs, the Main Belt, and the so-called
Scattered Disk), and also provide upper limits on the abundance of Centaurs and
Neptune's Trojans, as well as upper limits on the sizes and abundances of
hypothetical KBOs that might inhabit the a>50 AU zone.Comment: 60 pages, 16 figures. Accepted for publication in the Astronomical
Journa
Dynamical density functional theory analysis of the laning instability in sheared soft matter
Using dynamical density functional theory (DDFT) methods we investigate the
laning instability of a sheared colloidal suspension. The nonequilibrium
ordering at the laning transition is driven by non-affine particle motion
arising from interparticle interactions. Starting from a DDFT which
incorporates the non-affine motion, we perform a linear stability analysis that
enables identification of the regions of parameter space where lanes form. We
illustrate our general approach by applying it to a simple one-component fluid
of soft penetrable particles
Effects of homeownership on children: the role of neighborhood characteristics and family income
This paper was presented at the conference "Policies to Promote Affordable Housing," cosponsored by the Federal Reserve Bank of New York and New York University's Furman Center for Real Estate and Urban Policy, February 7, 2002. It was part of Session 3: The Impact of Housing on People and Places.Housing ; Community development ; Demography ; Population ; Education
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