31,381 research outputs found
Cross-Modal Message Passing for Two-stream Fusion
Processing and fusing information among multi-modal is a very useful
technique for achieving high performance in many computer vision problems. In
order to tackle multi-modal information more effectively, we introduce a novel
framework for multi-modal fusion: Cross-modal Message Passing (CMMP).
Specifically, we propose a cross-modal message passing mechanism to fuse
two-stream network for action recognition, which composes of an appearance
modal network (RGB image) and a motion modal (optical flow image) network. The
objectives of individual networks in this framework are two-fold: a standard
classification objective and a competing objective. The classification object
ensures that each modal network predicts the true action category while the
competing objective encourages each modal network to outperform the other one.
We quantitatively show that the proposed CMMP fuses the traditional two-stream
network more effectively, and outperforms all existing two-stream fusion method
on UCF-101 and HMDB-51 datasets.Comment: 2018 IEEE International Conference on Acoustics, Speech and Signal
Processin
Observe matter falling into a black hole
It has been well known that in the point of view of a distant observer, all
in-falling matter to a black hole (BH) will be eventually stalled and "frozen"
just outside the event horizon of the BH, although an in-falling observer will
see the matter falling straight through the event horizon. Thus in this "frozen
star" scenario, as distant observers, we could never observe matter falling
into a BH, neither could we see any "real" BH other than primordial ones, since
all other BHs are believed to be formed by matter falling towards singularity.
Here we first obtain the exact solution for a pressureless mass shell around a
pre-existing BH. The metrics inside and interior to the shell are all different
from the Schwarzschild metric of the enclosed mass. The metric interior to the
shell can be transformed to the Schwarzschild metric for a slower clock which
is dependent of the location and mass of the shell. Another result is that
there does not exist a singularity nor event horizon in the shell. Therefore
the "frozen star" scenario is incorrect. We also show that for all practical
astrophysical settings the in-falling time recorded by an external observer is
sufficiently short that future astrophysical instruments may be able to follow
the whole process of matter falling into BHs. The distant observer could not
distinguish between a "real" BH and a "frozen star", until two such objects
merge together. It has been proposed that electromagnetic waves will be
produced when two "frozen stars" merge together, but not true when two "real"
bare BHs merge together. However gravitational waves will be produced in both
cases. Thus our solution is testable by future high sensitivity astronomical
observations.Comment: 7 pages, 2 figures. Proceeding of the conference "Astrophysics of
Compact Objects", 1-7 July, Huangshan, China. Abridged abstrac
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