67 research outputs found
Multi-Entity Dependence Learning with Rich Context via Conditional Variational Auto-encoder
Multi-Entity Dependence Learning (MEDL) explores conditional correlations
among multiple entities. The availability of rich contextual information
requires a nimble learning scheme that tightly integrates with deep neural
networks and has the ability to capture correlation structures among
exponentially many outcomes. We propose MEDL_CVAE, which encodes a conditional
multivariate distribution as a generating process. As a result, the variational
lower bound of the joint likelihood can be optimized via a conditional
variational auto-encoder and trained end-to-end on GPUs. Our MEDL_CVAE was
motivated by two real-world applications in computational sustainability: one
studies the spatial correlation among multiple bird species using the eBird
data and the other models multi-dimensional landscape composition and human
footprint in the Amazon rainforest with satellite images. We show that
MEDL_CVAE captures rich dependency structures, scales better than previous
methods, and further improves on the joint likelihood taking advantage of very
large datasets that are beyond the capacity of previous methods.Comment: The first two authors contribute equall
Large energy soliton erbium-doped fiber laser with a graphene-polymer composite mode locker
Due to its unique electronic property and the Pauli Blocking Principle,
atomic layer graphene possesses wavelength-independent ultrafast saturable
absorption, which can be exploited for the ultrafast photonics application.
Through chemical functionalization, a graphene-polymer nanocomposite membrane
was fabricated and firstly used to mode lock a fiber laser. Stable mode locked
solitons with 3 nJ pulse energy, 700 fs pulse width at the 1590 nm wavelength
have been directly generated from the laser. We show that graphene-polymer
nanocomposites could be an attractive saturable absorber for high power fiber
laser mode locking.Comment: Large energy soliton erbium-doped fiber laser with a graphene-polymer
composite mode locker. Applied Physics Letters, Accepte
Graphene mode locked, wavelength-tunable, dissipative soliton fiber laser
Atomic layer graphene possesses wavelength-insensitive ultrafast saturable
absorption, which can be exploited as a full-band mode locker. Taking advantage
of the wide band saturable absorption of the graphene, we demonstrate
experimentally that wide range (1570 nm - 1600nm) continuous wavelength tunable
dissipative solitons could be formed in an erbium doped fiber laser mode locked
with few layer graphene
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