3,008 research outputs found
Study on separation characteristics of two-phase flow in double helical separator
The helical separator plays an important role in improving the working efficiency of electric submersible pump. Separation efficiency of two-phase flow in double helical separator is studied by numerical simulation and theoretical calculation. It is found that the separation efficiency of helical separator increases with the increase of gas-liquid ratio and flow rate. At the same time, under the condition of constant helical number and gas-liquid ratio, the separation efficiency is best when the even difference of pitch is 10Β mm
(1S*,5R*)-9-Phenyl-9-azaΒbicycloΒ[3.3.1]nonan-3-one
In the title compound, C14H17NO, the piperidinone and piperidine rings both adopt a chair conformation. The chiral crystals were obtained from a racemic reaction product via spontaneous resolution
A Method for forcasting Salinity Process in Seawater-Intruded Rivers
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
2011-2012 Master Class - Elmar Oliveira (Violin)
https://spiral.lynn.edu/conservatory_masterclasses/1070/thumbnail.jp
A Validation Approach to Over-parameterized Matrix and Image Recovery
In this paper, we study the problem of recovering a low-rank matrix from a
number of noisy random linear measurements. We consider the setting where the
rank of the ground-truth matrix is unknown a prior and use an overspecified
factored representation of the matrix variable, where the global optimal
solutions overfit and do not correspond to the underlying ground-truth. We then
solve the associated nonconvex problem using gradient descent with small random
initialization. We show that as long as the measurement operators satisfy the
restricted isometry property (RIP) with its rank parameter scaling with the
rank of ground-truth matrix rather than scaling with the overspecified matrix
variable, gradient descent iterations are on a particular trajectory towards
the ground-truth matrix and achieve nearly information-theoretically optimal
recovery when stop appropriately. We then propose an efficient early stopping
strategy based on the common hold-out method and show that it detects nearly
optimal estimator provably. Moreover, experiments show that the proposed
validation approach can also be efficiently used for image restoration with
deep image prior which over-parameterizes an image with a deep network.Comment: 29 pages and 9 figure
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