5,737 research outputs found
Scalable Estimation of Precision Maps in a MapReduce Framework
This paper presents a large-scale strip adjustment method for LiDAR mobile
mapping data, yielding highly precise maps. It uses several concepts to achieve
scalability. First, an efficient graph-based pre-segmentation is used, which
directly operates on LiDAR scan strip data, rather than on point clouds.
Second, observation equations are obtained from a dense matching, which is
formulated in terms of an estimation of a latent map. As a result of this
formulation, the number of observation equations is not quadratic, but rather
linear in the number of scan strips. Third, the dynamic Bayes network, which
results from all observation and condition equations, is partitioned into two
sub-networks. Consequently, the estimation matrices for all position and
orientation corrections are linear instead of quadratic in the number of
unknowns and can be solved very efficiently using an alternating least squares
approach. It is shown how this approach can be mapped to a standard key/value
MapReduce implementation, where each of the processing nodes operates
independently on small chunks of data, leading to essentially linear
scalability. Results are demonstrated for a dataset of one billion measured
LiDAR points and 278,000 unknowns, leading to maps with a precision of a few
millimeters.Comment: ACM SIGSPATIAL'16, October 31-November 03, 2016, Burlingame, CA, US
Dressing preserving the fundamental group
In this note we consider the relationship between the dressing action and the
holonomy representation in the context of constant mean curvature surfaces. We
characterize dressing elements that preserve the topology of a surface and
discuss dressing by simple factors as a means of adding bubbles to a class of
non finite type cylinders.Comment: 36 pages, 1 figur
NLO Simulations of Chargino Production at the ILC
We present an extension of the Monte Carlo Event Generator Whizard which
includes chargino production at the ILC at NLO. We present two ways of adding
photonic contributions. We present results for cross sections and event
generation.Comment: 4 pages, to appear in Proceedings of SUSY06, the 14th International
Conference on Supersymmetry and the Unification of Fundamental Interactions,
UC Irvine, California, 12-17 June 200
Simplified Models for New Physics in Vector Boson Scattering - Input for Snowmass 2013
In this contribution to the Snowmass process 2013 (which is a preliminary
version of [1]) we give a brief review of how new physics could enter in the
electroweak (EW) sector of the Standard Model (SM). This new physics, if it is
directly accessible at low energies, can be parameterized by explicit
resonances having certain quantum numbers. The extreme case is the decoupling
limit where those resonances are very heavy and leave only traces in the form
of deviations in the SM couplings. Translations are given into
higher-dimensional operators leading to such deviations. As long as such
resonances are introduced without a UV-complete theory behind it, these models
suffer from unitarity violation of perturbative scattering amplitudes. We show
explicitly how theoretically sane descriptions could be achieved by using a
unitarization prescription that allows a correct description of such a
resonance without specifying a UV-complete model.Comment: A Snowmass White Paper, minor typos, one formula update
WHIZARD 2.2 for Linear Colliders
We review the current status of the WHIZARD event generator. We discuss, in
particular, recent improvements and features that are relevant for simulating
the physics program at a future Linear Collider.Comment: Talk presented at the International Workshop on Future Linear
Colliders (LCWS13), Tokyo, Japan, 11-15 November 201
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