2,143,940 research outputs found
Experimental evidence for mixed reality states
Recently researchers at the University of Illinois coupled a real pendulum to
its virtual counterpart. They observed that the two pendulums suddenly start to
move in synchrony if their lengths are sufficiently close. In this synchronized
state, the boundary between the real system and the virtual system is blurred,
that is, the pendulums are in a mixed reality state. An instantaneous,
bidirectional coupling is a prerequisite for mixed reality states. In this
article we explore the implications of mixed reality states in the context of
controlling real-world systems.Comment: 2 pages, 2 figure
Evidence For Mixed Helicity in Erupting Filaments
Erupting filaments are sometimes observed to undergo a rotation about the
vertical direction as they rise. This rotation of the filament axis is
generally interpreted as a conversion of twist into writhe in a kink-unstable
magnetic flux rope. Consistent with this interpretation, the rotation is
usually found to be clockwise (as viewed from above) if the post-eruption
arcade has right-handed helicity, but counterclockwise if it has left-handed
helicity. Here, we describe two non--active-region filament events recorded
with the Extreme-Ultraviolet Imaging Telescope (EIT) on the {\it Solar and
Heliospheric Observatory} ({\it SOHO}), in which the sense of rotation appears
to be opposite to that expected from the helicity of the post-event arcade.
Based on these observations, we suggest that the rotation of the filament axis
is in general determined by the net helicity of the erupting system, and that
the axially aligned core of the filament can have the opposite helicity sign to
the surrounding field. In most cases, the surrounding field provides the main
contribution to the net helicity. In the events reported here, however, the
helicity associated with the filament ``barbs'' is opposite in sign to and
dominates that of the overlying arcade.Comment: ApJ, accepte
Policies for mixed communities: faith-based displacement activity?
The belief that it is fairer if communities are ``mixed'' can be traced at least to the late nineteenth century and the founders of the Garden City Movement. The idea is now firmly established in Organization for Economic Cooperation and Development (OECD) and national policies. This article reviews the evidence and argues that this is essentially a faith-based policy because there is scant real evidence that making communities more mixed makes the life chances of the poor any better. There is overwhelming evidence that the attributes that make neighborhoods attractive are capitalized into house prices/rents. The result is that poor people cannot afford to buy into nicer neighborhoods, which anyway have amenities of no value to them. Moreover, ``specialized neighborhoods'' are an important element in agglomeration economies and seem to be welfare enhancing. Thus, policies for mixed neighborhoods treat the symptoms rather than the causes of poverty. Efforts to improve social equity would be more effectively directed toward people themselves rather than moving people around to mix neighborhoods
Selection into Mixed Marriages: Evidence from North Carolina, 1894-1906
Using a novel dataset from agricultural censuses and geological sources, I examine the selec- tion into mixed marriages between whites and Cherokee Indians in North Carolina during the late nineteenth century. I find that the well-documented wealth advantage of Cherokee Indian households containing white husbands is driven mostly by positive selection. Thus, once family fixed effects are controlled for, the observed intermarriage premium is completely eliminated. (JEL D03, N31, O12.
CO on Titan: More Evidence for a Well-Mixed Vertical Profile
We report new interferometric observations of the CO (2-1) rotational
transition on Titan. We find that the spectrum is best fit by a uniform profile
of 52 ppm, with estimated errors of 6 ppm (40 to 200 km) and 12 ppm (200 to 300
km).Comment: Submitted to as a Note to Icarus. Uses emulateapj.sty under Latex, 6
text pages, 2 figs (includes with psfig
Hardy's criterion of nonlocality for mixed states
We generalize Hardy's proof of nonlocality to the case of bipartite mixed
statistical operators, and we exhibit a necessary condition which has to be
satisfied by any given mixed state in order that a local and realistic
hidden variable model exists which accounts for the quantum mechanical
predictions implied by . Failure of this condition will imply both the
impossibility of any local explanation of certain joint probability
distributions in terms of hidden variables and the nonseparability of the
considered mixed statistical operator. Our result can be also used to determine
the maximum amount of noise, arising from imperfect experimental
implementations of the original Hardy's proof of nonlocality, in presence of
which it is still possible to put into evidence the nonlocal features of
certain mixed states.Comment: 7 pages, RevTe
Mixed tenure orthodoxy: practitioner reflections on policy effects
This article examines mixed tenure as a policy orthodoxy. It first sets out how mixed tenure may be considered to constitute an orthodoxy within planning, being generally accepted as a theory and practice even in the absence of supporting evidence. Five elements of this orthodoxy are identified, relating to (1) housing and the environment, (2) social change, (3) economic impacts, (4) sustainable communities, (5) and sociospatial integration. Interviews with practitioners involved with three social housing estates that have experienced mixed-tenure policy interventions are reported to consider why the implementation and effects of mixed tenure might not correspond with the orthodox understanding. It is argued that policy ambiguity and weaknesses in policy theory and specification, alongside practical constraints, lie behind incomplete and counterproductive policy implementation, but a belief in pursuing the policy orthodoxy persists nevertheless
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