3,485 research outputs found
Continuous Action Recognition Based on Sequence Alignment
Continuous action recognition is more challenging than isolated recognition
because classification and segmentation must be simultaneously carried out. We
build on the well known dynamic time warping (DTW) framework and devise a novel
visual alignment technique, namely dynamic frame warping (DFW), which performs
isolated recognition based on per-frame representation of videos, and on
aligning a test sequence with a model sequence. Moreover, we propose two
extensions which enable to perform recognition concomitant with segmentation,
namely one-pass DFW and two-pass DFW. These two methods have their roots in the
domain of continuous recognition of speech and, to the best of our knowledge,
their extension to continuous visual action recognition has been overlooked. We
test and illustrate the proposed techniques with a recently released dataset
(RAVEL) and with two public-domain datasets widely used in action recognition
(Hollywood-1 and Hollywood-2). We also compare the performances of the proposed
isolated and continuous recognition algorithms with several recently published
methods
Rapid magnetic oscillations and magnetic breakdown in quasi-1D conductors
We review the physics of magnetic quantum oscillations in quasi-one
dimensional conductors with an open Fermi surface, in the presence of modulated
order. We emphasize the difference between situations where a modulation
couples states on the same side of the Fermi surface and a modulation couples
states on opposite sides of the Fermi surface. We also consider cases where
several modulations coexist, which may lead to a complex reorganization of the
Fermi surface. The interplay between nesting effects and magnetic breakdown is
discussed. The experimental situation is reviewed.Comment: 10 pages, 8 figures, Contribution to the memorial issue in honor of
J. Friedel, C. R. Acad. Sci. Pari
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