2,391 research outputs found
Gap bootstrap methods for massive data sets with an application to transportation engineering
In this paper we describe two bootstrap methods for massive data sets. Naive
applications of common resampling methodology are often impractical for massive
data sets due to computational burden and due to complex patterns of
inhomogeneity. In contrast, the proposed methods exploit certain structural
properties of a large class of massive data sets to break up the original
problem into a set of simpler subproblems, solve each subproblem separately
where the data exhibit approximate uniformity and where computational
complexity can be reduced to a manageable level, and then combine the results
through certain analytical considerations. The validity of the proposed methods
is proved and their finite sample properties are studied through a moderately
large simulation study. The methodology is illustrated with a real data example
from Transportation Engineering, which motivated the development of the
proposed methods.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS587 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Top Yukawa coupling measurement with indefinite CP Higgs in
We consider the issue of the top quark Yukawa coupling measurement in a model
in dependent and general case with the inclusion of CP-violation in the
coupling. Arguably the best process to study this coupling is the associa ted
production of Higgs boson along with a pair in a machine like the
International Linear Collider (ILC). While detailed analyses of the sensitivity
of the measurement assuming a Standard Model (SM) - like coupling are available
in the context of ILC, conclude that th e coupling could be pinned down at
about 10\% level with modest luminosity, our investigations show that the
scenario could be different in case of a more general coupling. The modified
Lorentz structure resulting in a changed functional dependence of the cross
section on the couplin g, along with the difference in the cross section itself
leads to considerable deviation in the sensitivity. Our studies with an ILC of
center of mass energies of 500 GeV, 800 GeV and 1000 GeV show that moderate
CP-mixing in the Higgs sector could change the sensitivity to about 20\ %,
while it could be worsened to 75\% in cases which could accommodate more
dramatic changes in the coupling. While detailed considerations of the decay
distributions point to a need for a relook at the analysis strategy followed
for the case of SM such as for a model independent analysis of the top quark
Yukawa coupling measurement. This study strongly suggests that, a joint
analysis of the CP properties and the Yukawa coupling measurement would be the
way forward at the ILC and that caution must be excercised in the measurem ent
of the Yukawa couplings and the conclusions drawn from it.Comment: 18 pages, 7 figures, uses revte
Artificial neural network model with the parameter tuning assisted by a differential evolution technique: the study of the hold up of the slurry flow in a pipeline
This paper describes a robust hybrid artificial neural network (ANN) methodology which can offer a superior performance for the important process engineering problems. The method incorporates a hybrid artificial neural network and differential evolution technique (ANN-DE) for the efficient tuning of ANN meta parameters. The algorithm has been applied for the prediction of the hold up of the solid liquid slurry flow. A comparison with selected correlations in the literature showed that the developed ANN correlation noticeably improved the prediction of hold up over a wide range of operating conditions, physical properties, and pipe diameters
Local symmetries of the non-Abelian two-form
It is proposed that a non-Abelian adjoint two-form in BF type theories
transform inhomogeneously under the gauge group. The resulting restrictions on
invariant actions are discussed. The auxiliary one-form which is required for
maintaining vector gauge symmetry transforms like a second gauge field, and
hence cannot be fully absorbed in the two-form. But it can be replaced, via a
vector gauge transformation, by the usual gauge field, leading to gauge
equivalences between different types of theories. A new type of symmetry also
appears, one which depends on local functions but cannot be generated by
constraints. It is connected to the identity in the limit of a vanishing global
parameter, so it should be called a semiglobal symmetry. The corresponding
conserved currents and BRST charges are parametrized by the space of flat
connections.Comment: RevTeX4, 11 pages, minor correction
A nilpotent symmetry of quantum gauge theories
For the Becchi-Rouet-Stora-Tyutin (BRST) invariant extended action for any
gauge theory, there exists another off-shell nilpotent symmetry. For linear
gauges, it can be elevated to a symmetry of the quantum theory and used in the
construction of the quantum effective action. Generalizations for nonlinear
gauges and actions with higher order ghost terms are also possible.Comment: RevTeX, 9 pages, several changes to include generalizations to
quartic and higher ghost terms and non-linear gauges. Abstract changed. Final
version to be publishe
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