36,708 research outputs found
On the Benjamini--Hochberg method
We investigate the properties of the Benjamini--Hochberg method for multiple
testing and of a variant of Storey's generalization of it, extending and
complementing the asymptotic and exact results available in the literature.
Results are obtained under two different sets of assumptions and include
asymptotic and exact expressions and bounds for the proportion of rejections,
the proportion of incorrect rejections out of all rejections and two other
proportions used to quantify the efficacy of the method.Comment: Published at http://dx.doi.org/10.1214/009053606000000425 in the
Annals of Statistics (http://www.imstat.org/aos/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The Conserved Charges and Integrability of the Conformal Affine Toda Models
We construct infinite sets of local conserved charges for the conformal
affine Toda model. The technique involves the abelianization of the
two-dimensional gauge potentials satisfying the zero-curvature form of the
equations of motion. We find two infinite sets of chiral charges and apart from
two lowest spin charges all the remaining ones do not possess chiral densities.
Charges of different chiralities Poisson commute among themselves. We discuss
the algebraic properties of these charges and use the fundamental Poisson
bracket relation to show that the charges conserved in time are in involution.
Connections to other Toda models are established by taking particular limits.Comment: 18 pages, LaTeX, (one appendix and one reference added, small changes
in introduction and conclusions, eqs.(5.14) and (5.19) improved, final
version to appear in Int. J. Modern Phys. A
Constrained KP Models as Integrable Matrix Hierarchies
We formulate the constrained KP hierarchy (denoted by \cKP) as an
affine matrix integrable hierarchy generalizing the
Drinfeld-Sokolov hierarchy. Using an algebraic approach, including the graded
structure of the generalized Drinfeld-Sokolov hierarchy, we are able to find
several new universal results valid for the \cKP hierarchy. In particular, our
method yields a closed expression for the second bracket obtained through Dirac
reduction of any untwisted affine Kac-Moody current algebra. An explicit
example is given for the case , for which a closed
expression for the general recursion operator is also obtained. We show how
isospectral flows are characterized and grouped according to the semisimple
{\em non-regular} element of and the content of the center of
the kernel of .Comment: LaTeX, 19 pg
Out-of-plane seismic response of stone masonry walls: experimental and analytical study of real piers
This paper presents the application of an existing simplified displacement-based procedure to the
characterization of the nonlinear force-displacement relationship for the out-of-plane behaviour of
unreinforced traditional masonry walls. According to this procedure, tri-linear models based on three
different energy based criteria were constructed and confronted with three experimental tests on
existing stone masonry constructions. Moreover, a brief introduction is presented regarding the main
characteristics of the in situ cyclic testing recently carried out using distributed loads, as well as results
obtained during the experimental campaigns performed. The comparison between the experimental and the analytical results are presented and discussed
Streaming velocities as a dynamical estimator of Omega
It is well known that estimating the pairwise velocity of galaxies, v_{12},
from the redshift space galaxy correlation function is difficult because this
method is highly sensitive to the assumed model of the pairwise velocity
dispersion. Here we propose an alternative method to estimate v_{12} directly
from peculiar velocity samples, which contain redshift-independent distances as
well as galaxy redshifts. In contrast to other dynamical measures which
determine beta = sigma_8 x Omega^{0.6}, our method can provide an estimate of
(sigma_8)^2 x Omega^{0.6} for a range of sigma_8 (here Omega is the
cosmological mass density parameter while sigma_8 is the standard normalization
parameter for the spectrum of matter density fluctuations). We demonstrate how
to measure this quantity from realistic catalogues.Comment: 8 pages of text, 4 figures Subject headings: Cosmology: theory -
observation - peculiar velocities: large scale flows Last name of one of the
authors was misspelled. It is now corrected. Otherwise the manuscript is
identical to its original versio
Confined magneto-optical waves in graphene
The electromagnetic mode spectrum of single-layer graphene subjected to a
quantizing magnetic field is computed taking into account intraband and
interband contributions to the magneto-optical conductivity. We find that a
sequence of weakly decaying quasi-transverse-electric modes, separated by
magnetoplasmon polariton modes, emerge due to the quantizing magnetic field.
The characteristics of these modes are tuneable, by changing the magnetic field
or the Fermi energy.Comment: 9 pages, 7 figures. published version: text and figures revised and
updated + new references and one figure adde
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