65 research outputs found
Evolving parametrized Loss for Image Classification Learning on Small Datasets
This paper proposes a meta-learning approach to evolving a parametrized loss
function, which is called Meta-Loss Network (MLN), for training the image
classification learning on small datasets. In our approach, the MLN is embedded
in the framework of classification learning as a differentiable objective
function. The MLN is evolved with the Evolutionary Strategy algorithm (ES) to
an optimized loss function, such that a classifier, which optimized to minimize
this loss, will achieve a good generalization effect. A classifier learns on a
small training dataset to minimize MLN with Stochastic Gradient Descent (SGD),
and then the MLN is evolved with the precision of the small-dataset-updated
classifier on a large validation dataset. In order to evaluate our approach,
the MLN is trained with a large number of small sample learning tasks sampled
from FashionMNIST and tested on validation tasks sampled from FashionMNIST and
CIFAR10. Experiment results demonstrate that the MLN effectively improved
generalization compared to classical cross-entropy error and mean squared
error
Graph Few-shot Learning via Knowledge Transfer
Towards the challenging problem of semi-supervised node classification, there
have been extensive studies. As a frontier, Graph Neural Networks (GNNs) have
aroused great interest recently, which update the representation of each node
by aggregating information of its neighbors. However, most GNNs have shallow
layers with a limited receptive field and may not achieve satisfactory
performance especially when the number of labeled nodes is quite small. To
address this challenge, we innovatively propose a graph few-shot learning (GFL)
algorithm that incorporates prior knowledge learned from auxiliary graphs to
improve classification accuracy on the target graph. Specifically, a
transferable metric space characterized by a node embedding and a
graph-specific prototype embedding function is shared between auxiliary graphs
and the target, facilitating the transfer of structural knowledge. Extensive
experiments and ablation studies on four real-world graph datasets demonstrate
the effectiveness of our proposed model.Comment: Full paper (with Appendix) of AAAI 202
A Novel BiLevel Paradigm for Image-to-Image Translation
Image-to-image (I2I) translation is a pixel-level mapping that requires a
large number of paired training data and often suffers from the problems of
high diversity and strong category bias in image scenes. In order to tackle
these problems, we propose a novel BiLevel (BiL) learning paradigm that
alternates the learning of two models, respectively at an instance-specific
(IS) and a general-purpose (GP) level. In each scene, the IS model learns to
maintain the specific scene attributes. It is initialized by the GP model that
learns from all the scenes to obtain the generalizable translation knowledge.
This GP initialization gives the IS model an efficient starting point, thus
enabling its fast adaptation to the new scene with scarce training data. We
conduct extensive I2I translation experiments on human face and street view
datasets. Quantitative results validate that our approach can significantly
boost the performance of classical I2I translation models, such as PG2 and
Pix2Pix. Our visualization results show both higher image quality and more
appropriate instance-specific details, e.g., the translated image of a person
looks more like that person in terms of identity
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