3,555 research outputs found
Deep Joint Source Channel Coding With Attention Modules Over MIMO Channels
In this paper, we propose two deep joint source and channel coding (DJSCC)
structures with attention modules for the multi-input multi-output (MIMO)
channel, including a serial structure and a parallel structure. With singular
value decomposition (SVD)-based precoding scheme, the MIMO channel can be
decomposed into various sub-channels, and the feature outputs will experience
sub-channels with different channel qualities. In the serial structure, one
single network is used at both the transmitter and the receiver to jointly
process data streams of all MIMO subchannels, while data steams of different
MIMO subchannels are processed independently via multiple sub-networks in the
parallel structure. The attention modules in both serial and parallel
architectures enable the system to adapt to varying channel qualities and
adjust the quantity of information outputs in accordance with the channel
qualities. Experimental results demonstrate the proposed DJSCC structures have
improved image transmission performance, and reveal the phenomenon via
non-parameter entropy estimation that the learned DJSCC transceivers tend to
transmit more information over better sub-channels
Optical spin pumping induced pseudo-magnetic field in two dimensional heterostructures
Two dimensional heterostructures are likely to provide new avenues for the
manipulation of magnetization that is crucial for spintronics or
magnetoelectronics. Here, we demonstrate that optical spin pumping can generate
a large effective magnetic field in two dimensional MoSe2/WSe2
heterostructures. We determine the strength of the generated field by
polarization-resolved measurement of the interlayer exciton photoluminescence
spectrum: the measured splitting exceeding 10 milli-electron volts (meV)
between the emission originating from the two valleys corresponds to an
effective magnetic field of ~ 30 T. The strength of this optically induced
field can be controlled by the excitation light polarization. Our finding opens
up new possibilities for optically controlled spintronic devices based on van
der Waals heterostructures
Honeybee (Apis mellifera) Maternal Effect Causes Alternation of DNA Methylation Regulating Queen Development
Queen-worker caste dimorphism is a typical trait for honeybees (Apis mellifera). We previously showed a maternal effect on caste differentiation and queen development, where queens emerged from queen-cell eggs (QE) had higher quality than queens developed from worker cell eggs (WE). In this study, newly-emerged queens were reared from QE, WE, and 2-day worker larvae (2L). The thorax size and DNA methylation levels of queens were measured. We found that queens emerging from QE had significantly larger thorax length and width than WE and 2L. Epigenetic analysis showed that QE/2L comparison had the most different methylated genes (DMGs, 612) followed by WE/2L (473), and QE/WE (371). Interestingly, a great number of DMGs (42) were in genes belonging to mTOR, MAPK, Wnt, Notch, Hedgehog, FoxO, and Hippo signaling pathways that are involved in regulating caste differentiation, reproduction and longevity. This study proved that honeybee maternal effect causes epigenetic alteration regulating caste differentiation and queen development
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