18,809 research outputs found
House prices and the proposed expansion of Chicago's O'Hare Airport
Quieter aircraft are causing the 65-db noise contour band around O'Hare Airport to shrink over time, even in the event that air traffic increases by nearly 60 percent after the proposed expansion of the airport. Forecasts imply that home prices will increase by nearly $280 million (in 1997 dollars) between 1997 and the time after the expansion of the airport as the number of homes subject to severe noise falls.Chicago (Ill.) ; Housing - Prices
A Lack of Resolved Near-Infrared Polarization Across the Face of M51
The galaxy M51 was observed using the Mimir instrument on the Perkins
telescope to constrain the resolved H-band (1.6 m) polarization across the
galaxy. These observations place an upper limit of on the -band
polarization across the face of M51, at 0.6 arcsecond pixel sampling. Even with
smoothing to coarser angular resolutions, to reduce polarization uncertainty,
the -band polarization remains undetected. The polarization upper limit at
-band, when combined with previous resolved optical polarimetry, rules out a
Serkowski-like polarization dependence on wavelength. Other polarization
mechanisms cannot account for the observed polarization ratio () across the face of M51.Comment: 4 pages, 2 figures, Accepted for publication in ApJ
Extended MSSM Neutralinos as the Source of the PAMELA Positron Excess
We consider a scenario within the Minimal Supersymmetric Standard Model
extended by a singlet chiral superfield, in which neutralino dark matter
annihilates to light singlet-like Higgs bosons, which proceed to decay to
either electron-positron or muon-antimuon pairs. Unlike neutralino
annihilations in the MSSM, this model can provide a good fit to the PAMELA
cosmic ray positron fraction excess. Furthermore, the singlet-like scalar Higgs
can induce a large Sommerfeld enhancement and provide an annihilation rate
sufficient to accommodate the observed positron excess
A Toy Model for Topology Change Transitions: Role of Curvature Corrections
We consider properties of near-critical solutions describing a test static
axisymmetric D-dimensional brane interacting with a bulk N-dimensional black
hole (N>D). We focus our attention on the effects connected with curvature
corrections to the brane action. Namely, we demonstrate that the second order
phase transition in such a system is modified and becomes first order. We
discuss possible consequences of these results for merger transitions between
caged black holes and black strings.Comment: 11 pages, 9 figures, v2: published versio
Capturing Preference Heterogeneity in Stated Choice Models: A Random Parameter Logit Model of the Demand for GM Food
Analyses of data from random utility models of choice data have typically used fixed parameter representations, with consumer heterogeneity introduced by including factors such as the age, gender etc of the respondent. However, there is a class of models that assume that the underlying parameters of the estimated model (and hence preferences) are different for each individual within the sample, and that choices can be explained by identifying the parameters of the distribution from which they are drawn. Such a random parameter model is applied to stated choice data from the UK, and the results compared with standard fixed parameter models. The results provide new evidence of preferences for various aspects of the UK food system, particularly in relation to GM food but other environmental and technical aspects also. Indications of how random parameter models might be developed further are discussed on the basis of these results.random parameter logit, choice modelling, GMOs, food safety, Food Consumption/Nutrition/Food Safety,
Transients of platoons with asymmetric and different Laplacians
We consider an asymmetric control of platoons of identical vehicles with
nearest-neighbor interaction. Recent results show that if the vehicle uses
different asymmetries for position and velocity errors, the platoon has a short
transient and low overshoots. In this paper we investigate the properties of
vehicles with friction. To achieve consensus, an integral part is added to the
controller, making the vehicle a third-order system. We show that the
parameters can be chosen so that the platoon behaves as a wave equation with
different wave velocities. Simulations suggest that our system has a better
performance than other nearest-neighbor scenarios. Moreover, an
optimization-based procedure is used to find the controller properties
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