13,177 research outputs found
Regression with strongly correlated data
This paper discusses linear regression of strongly correlated data that
arises, for example, in magnetohydrodynamic equilibrium reconstructions. We
have proved that, generically, the covariance matrix of the estimated
regression parameters for fixed sample size goes to zero as the correlations
become unity. That is, in this limit the estimated parameters are known with
perfect accuracy. Simple examples are shown to illustrate this effect and the
nature of the exceptional cases in which the estimate covariance does not go to
zero
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Addressing School Dropout in Texas: A Summary for Administrators and Policymakers of "Dropout Prevention: A Practice Guide"
This booklet summarizes the information from: Dropout Prevention: A Practice Guide, available on the Institute of Education Sciences web site at http://ies.ed.gov/ncee/wwc.Educatio
Argentina's recovery and "excess" capital shallowing of the 1990s
The paper examines Argentina’s economic expansion in the 1990s through the lens of a parsimonious neoclassical growth model. The main finding is that investment remained considerably weaker than what the model would have predicted. The resulting excessive “capital shallowing” could be identified as a weakness of the rapid economic growth of the 1990s that may have played a role in Argentina’s ultimate inability to escape the crisis that started to unfold towards the end of that decade. ; Economic Research Working Paper 0204Capital
Swift Pointing and the Association Between Gamma-Ray Bursts and Gravitational-Wave Bursts
The currently accepted model for gamma-ray burst phenomena involves the
violent formation of a rapidly rotating solar mass black hole. Gravitational
waves should be associated with the black-hole formation, and their detection
would permit this model to be tested, the black hole progenitor (e.g.,
coalescing binary or collapsing stellar core) identified, and the origin of the
gamma rays (within the expanding relativistic fireball or at the point of
impact on the interstellar medium) located. Even upper limits on the
gravitational-wave strength associated with gamma-ray bursts could constrain
the gamma-ray burst model. To do any of these requires joint observations of
gamma-ray burst events with gravitational and gamma-ray detectors. Here we
examine how the quality of an upper limit on the gravitational-wave strength
associated with gamma-ray burst observations depends on the relative
orientation of the gamma-ray-burst and gravitational-wave detectors, and apply
our results to the particular case of the Swift Burst-Alert Telescope (BAT) and
the LIGO gravitational-wave detectors. A result of this investigation is a
science-based ``figure of merit'' that can be used, together with other mission
constraints, to optimize the pointing of the Swift telescope for the detection
of gravitational waves associated with gamma-ray bursts.Comment: aastex, 14 pages, 2 figure
Parity-expanded variational analysis for non-zero momentum
In recent years, the use of variational analysis techniques in lattice QCD
has been demonstrated to be successful in the investigation of the rest-mass
spectrum of many hadrons. However, due to parity-mixing, more care must be
taken for investigations of boosted states to ensure that the projected
correlation functions provided by the variational analysis correspond to the
same states at zero momentum. In this paper we present the Parity-Expanded
Variational Analysis (PEVA) technique, a novel method for ensuring the
successful and consistent isolation of boosted baryons through a parity
expansion of the operator basis used to construct the correlation matrix.Comment: 9 pages, 3 figures, 1 tabl
Self-consistent theory of equilibrium and acceleration of a high- current electron ring in a modified betatron
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