57,194 research outputs found
Improved Heterogeneous Distance Functions
Instance-based learning techniques typically handle continuous and linear
input values well, but often do not handle nominal input attributes
appropriately. The Value Difference Metric (VDM) was designed to find
reasonable distance values between nominal attribute values, but it largely
ignores continuous attributes, requiring discretization to map continuous
values into nominal values. This paper proposes three new heterogeneous
distance functions, called the Heterogeneous Value Difference Metric (HVDM),
the Interpolated Value Difference Metric (IVDM), and the Windowed Value
Difference Metric (WVDM). These new distance functions are designed to handle
applications with nominal attributes, continuous attributes, or both. In
experiments on 48 applications the new distance metrics achieve higher
classification accuracy on average than three previous distance functions on
those datasets that have both nominal and continuous attributes.Comment: See http://www.jair.org/ for an online appendix and other files
accompanying this articl
Spinning Relativistic Particle in an External Electromagnetic Field
The Hamiltonian formulation of the motion of a spinning relativistic particle
in an external electromagnetic field is considered. The approach is based on
the introduction of new coordinates and their conjugated momenta to describe
the spin degrees of freedom together with an appropriate set of constraints in
the Dirac formulation. For particles with gyromagnetic ratio , the
equations of motion do not predict any deviation from the standard Lorentz
force, while for an additional force, which corresponds to the
magnetic dipole force, is obtained.Comment: Latex file, 11 page
Z' boson detection in the Minimal Quiver Standard Model
We undertake a phenomenological study of the extra neutral Z' boson in the
Minimal Quiver Standard Model and discuss limits on the model's parameters from
previous precision electroweak experiments, as well as detection prospects at
the Large Hadron Collider at CERN. We find that masses lower than around 700
GeV are excluded by the -pole data from the CERN-LEP collider, and below 620
GeV by experimental data from di-electron events at the Fermilab-Tevatron
collider. We also find that at a mass of 1 TeV the LHC cross section would show
a small peak in the di-lepton and top pair channel.Comment: 15 pages, 5 figures. v2: substantial revisions and improvements,
final version accepted for publicatio
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