4,108 research outputs found
Kervolutional Neural Networks
Convolutional neural networks (CNNs) have enabled the state-of-the-art
performance in many computer vision tasks. However, little effort has been
devoted to establishing convolution in non-linear space. Existing works mainly
leverage on the activation layers, which can only provide point-wise
non-linearity. To solve this problem, a new operation, kervolution (kernel
convolution), is introduced to approximate complex behaviors of human
perception systems leveraging on the kernel trick. It generalizes convolution,
enhances the model capacity, and captures higher order interactions of
features, via patch-wise kernel functions, but without introducing additional
parameters. Extensive experiments show that kervolutional neural networks (KNN)
achieve higher accuracy and faster convergence than baseline CNN.Comment: oral paper in CVPR 201
Measuring the universal synchronization properties of coupled oscillators across the Hopf instability
When a driven oscillator loses phase-locking to a master oscillator via a
Hopf bifurcation, it enters a bounded-phase regime in which its average
frequency is still equal to the master frequency, but its phase displays
temporal oscillations. Here we characterize these two synchronization regimes
in a laser experiment, by measuring the spectrum of the phase fluctuations
across the bifurcation. We find experimentally, and confirm numerically, that
the low frequency phase noise of the driven oscillator is strongly suppressed
in both regimes in the same way. Thus the long-term phase stability of the
master oscillator is transferred to the driven one, even in the absence of
phase-locking. The numerical study of a generic, minimal model suggests that
such behavior is universal for any periodically driven oscillator near a Hopf
bifurcation point.Comment: 5 pages, 5 figure
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