1,045 research outputs found
Feature discovery and visualization of robot mission data using convolutional autoencoders and Bayesian nonparametric topic models
The gap between our ability to collect interesting data and our ability to
analyze these data is growing at an unprecedented rate. Recent algorithmic
attempts to fill this gap have employed unsupervised tools to discover
structure in data. Some of the most successful approaches have used
probabilistic models to uncover latent thematic structure in discrete data.
Despite the success of these models on textual data, they have not generalized
as well to image data, in part because of the spatial and temporal structure
that may exist in an image stream.
We introduce a novel unsupervised machine learning framework that
incorporates the ability of convolutional autoencoders to discover features
from images that directly encode spatial information, within a Bayesian
nonparametric topic model that discovers meaningful latent patterns within
discrete data. By using this hybrid framework, we overcome the fundamental
dependency of traditional topic models on rigidly hand-coded data
representations, while simultaneously encoding spatial dependency in our topics
without adding model complexity. We apply this model to the motivating
application of high-level scene understanding and mission summarization for
exploratory marine robots. Our experiments on a seafloor dataset collected by a
marine robot show that the proposed hybrid framework outperforms current
state-of-the-art approaches on the task of unsupervised seafloor terrain
characterization.Comment: 8 page
Distinguishing Signatures of top-and bottom-type heavy vectorlike quarks at the LHC
An SU(2) vectorlike singlet quark with a charge either +2/3 (t') or -1/3 (b')
is predicted in many extensions of the Standard Model. The mixing of these
quarks with the top or bottom lead to Flavor Changing Yukawa Interactions and
Neutral Current. The decay modes of the heavier mass eigenstates are therefore
different from the Standard Model type chiral quarks. The Large Hadron Collider
(LHC) will provide an ideal environment to look for the signals of these exotic
quarks. Considering all decays, including those involving Z- and Yukawa
interactions, we show how one can distinguish between t' and b' from ratios of
event rates with different lepton multiplicities. The ability to reconstruct
the Higgs boson with a mass around 125.5 GeV plays an important role in such
differentiation.Comment: 18 pages, 10 figure
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