5,102 research outputs found
Complete Study of Hadroproduction of a Meson Associated with a Prompt
We present the first complete study of and prompt
production from single-parton scattering, including the complete
color-singlet contribution, the
electroweak contribution, the complete
nonrelativistic S-wave and P-wave color-octet contribution as well as the
feeddown contribution. Our study was motivated by the recent evidence reported
by D0 Collaboration of prompt and simultaneous production
at the Tevatron. With our complete evaluation, we are able to refine the
determination of the double parton scattering contribution made by D0
Collaboration. We find that the effective cross section characterizing the
importance of double-parton scatterings is mb at
confidence level from the D0 measurement.Comment: 11 pages, 4 figures, 4 tables; v2: journal version, update the
references and fix a few typo
Object Tracking and Mensuration in Surveillance Videos
This thesis focuses on tracking and mensuration in surveillance videos. The
first part of the thesis discusses several object tracking approaches based on the
different properties of tracking targets. For airborne videos, where the targets are
usually small and with low resolutions, an approach of building motion models for
foreground/background proposed in which the foreground target is simplified as a
rigid object. For relatively high resolution targets, the non-rigid models are applied.
An active contour-based algorithm has been introduced. The algorithm is based on
decomposing the tracking into three parts: estimate the affine transform parameters
between successive frames using particle filters; detect the contour deformation using
a probabilistic deformation map, and regulate the deformation by projecting the
updated model onto a trained shape subspace. The active appearance Markov chain
(AAMC). It integrates a statistical model of shape, appearance and motion. In the
AAMC model, a Markov chain represents the switching of motion phases (poses),
and several pairwise active appearance model (P-AAM) components characterize the
shape, appearance and motion information for different motion phases. The second
part of the thesis covers video mensuration, in which we have proposed a heightmeasuring
algorithm with less human supervision, more flexibility and improved
robustness. From videos acquired by an uncalibrated stationary camera, we first
recover the vanishing line and the vertical point of the scene. We then apply a single
view mensuration algorithm to each of the frames to obtain height measurements.
Finally, using the LMedS as the cost function and the Robbins-Monro stochastic
approximation (RMSA) technique to obtain the optimal estimate
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