6,648 research outputs found
Large deviations for renormalized self-intersection local times of stable processes
We study large deviations for the renormalized self-intersection local time
of d-dimensional stable processes of index \beta \in (2d/3,d]. We find a
difference between the upper and lower tail. In addition, we find that the
behavior of the lower tail depends critically on whether \beta <d or \beta =d.Comment: Published at http://dx.doi.org/10.1214/009117904000001099 in the
Annals of Probability (http://www.imstat.org/aop/) by the Institute of
Mathematical Statistics (http://www.imstat.org
A Fully Convolutional Tri-branch Network (FCTN) for Domain Adaptation
A domain adaptation method for urban scene segmentation is proposed in this
work. We develop a fully convolutional tri-branch network, where two branches
assign pseudo labels to images in the unlabeled target domain while the third
branch is trained with supervision based on images in the pseudo-labeled target
domain. The re-labeling and re-training processes alternate. With this design,
the tri-branch network learns target-specific discriminative representations
progressively and, as a result, the cross-domain capability of the segmenter
improves. We evaluate the proposed network on large-scale domain adaptation
experiments using both synthetic (GTA) and real (Cityscapes) images. It is
shown that our solution achieves the state-of-the-art performance and it
outperforms previous methods by a significant margin.Comment: Accepted by ICASSP 201
Safe Mutations for Deep and Recurrent Neural Networks through Output Gradients
While neuroevolution (evolving neural networks) has a successful track record
across a variety of domains from reinforcement learning to artificial life, it
is rarely applied to large, deep neural networks. A central reason is that
while random mutation generally works in low dimensions, a random perturbation
of thousands or millions of weights is likely to break existing functionality,
providing no learning signal even if some individual weight changes were
beneficial. This paper proposes a solution by introducing a family of safe
mutation (SM) operators that aim within the mutation operator itself to find a
degree of change that does not alter network behavior too much, but still
facilitates exploration. Importantly, these SM operators do not require any
additional interactions with the environment. The most effective SM variant
capitalizes on the intriguing opportunity to scale the degree of mutation of
each individual weight according to the sensitivity of the network's outputs to
that weight, which requires computing the gradient of outputs with respect to
the weights (instead of the gradient of error, as in conventional deep
learning). This safe mutation through gradients (SM-G) operator dramatically
increases the ability of a simple genetic algorithm-based neuroevolution method
to find solutions in high-dimensional domains that require deep and/or
recurrent neural networks (which tend to be particularly brittle to mutation),
including domains that require processing raw pixels. By improving our ability
to evolve deep neural networks, this new safer approach to mutation expands the
scope of domains amenable to neuroevolution
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