48,975 research outputs found
Family Size and the Distribution of Per Capita Income
This paper is another contribution to the vast literature which addresses this issue: comparison of household income per capita among households of different structures requires judgment about the relationship between real income and family size. Our work uses a revealed preference approach in which household size/structure variables are included in empirical demand studies and the estimated coefficients on these variables are used to infer equivalence; it differs from many of the other studies not in basic concept but in its empirical strategy. While most studies build family composition effects into a relatively formal structural model of demand and impose considerable restriction in order to obtain an estimable system, we use a reduced-form approach which requires much less of the data.
Learning from one another: the U.S. and European banking experience
Banking structure ; European Economic Community
Unveiling the nature and interaction of the intermediate/high-mass YSOs in IRAS 20343+4129
In order to elucidate the nature of the brightest infrared sources associated
with IRAS 20343+4129, IRS1 and IRS3, we observed with the Submillimeter Array
(SMA) the 1.3 mm continuum and CO(2-1) emission of the region. Faint millimeter
dust continuum emission was detected toward IRS1, and we derived an associated
gas mass of ~0.8 Msun. The IRS1 spectral energy distribution agrees with IRS1
being an intermediate-mass Class I source of about 1000 Lsun, whose
circumstellar material is producing the observed large infrared excess. We have
discovered a high-velocity CO bipolar outflow in the east-west direction, which
is clearly associated with IRS1, and the outflow parameters are similar to
those of intermediate-mass young stellar objects. Associated with the blue
large scale CO outflow lobe, detected with single-dish observations, we only
found two elongated low-velocity structures on either side of IRS3. The
large-scale outflow lobe is almost completely resolved out by the SMA. Our
detected low-velocity CO structures are coincident with elongated H2 emission
features. The strongest millimeter continuum condensations in the region are
found on either side of IRS3, where the infrared emission is extremely weak,
and the CO and H2 elongated structures follow the border of the millimeter
continuum emission that is facing IRS3. All these results suggest that the dust
is associated with the walls of an expanding cavity driven by IRS3, estimated
to be a B2 star. Within and beyond the expanding cavity, the millimeter
continuum sources can be sites of future low-mass star formation.Comment: 12 pages, 7 figures, accepted for publication in A&
Newtonian and Relativistic Cosmologies
Cosmological N-body simulations are now being performed using Newtonian
gravity on scales larger than the Hubble radius. It is well known that a
uniformly expanding, homogeneous ball of dust in Newtonian gravity satisfies
the same equations as arise in relativistic FLRW cosmology, and it also is
known that a correspondence between Newtonian and relativistic dust cosmologies
continues to hold in linearized perturbation theory in the marginally
bound/spatially flat case. Nevertheless, it is far from obvious that Newtonian
gravity can provide a good global description of an inhomogeneous cosmology
when there is significant nonlinear dynamical behavior at small scales. We
investigate this issue in the light of a perturbative framework that we have
recently developed, which allows for such nonlinearity at small scales. We
propose a relatively straightforward "dictionary"---which is exact at the
linearized level---that maps Newtonian dust cosmologies into general
relativistic dust cosmologies, and we use our "ordering scheme" to determine
the degree to which the resulting metric and matter distribution solve
Einstein's equation. We find that Einstein's equation fails to hold at "order
1" at small scales and at "order " at large scales. We then find the
additional corrections to the metric and matter distribution needed to satisfy
Einstein's equation to these orders. While these corrections are of some
interest in their own right, our main purpose in calculating them is that their
smallness should provide a criterion for the validity of the original
dictionary (as well as simplified versions of this dictionary). We expect that,
in realistic Newtonian cosmologies, these additional corrections will be very
small; if so, this should provide strong justification for the use of Newtonian
simulations to describe relativistic cosmologies, even on scales larger than
the Hubble radius.Comment: 35 pages; minor change
Queueing process with excluded-volume effect
We introduce an extension of the M/M/1 queueing process with a spatial
structure and excluded- volume effect. The rule of particle hopping is the same
as for the totally asymmetric simple exclusion process (TASEP). A
stationary-state solution is constructed in a slightly arranged matrix product
form of the open TASEP. We obtain the critical line that separates the
parameter space depending on whether the model has the stationary state. We
calculate the average length of the model and the number of particles and show
the monotonicity of the probability of the length in the stationary state. We
also consider a generalization of the model with backward hopping of particles
allowed and an alternate joined system of the M/M/1 queueing process and the
open TASEP.Comment: 9 figure
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