论文标题
基于梯度的元学习,使用不确定性来称重损失,以进行几次学习
Gradient-Based Meta-Learning Using Uncertainty to Weigh Loss for Few-Shot Learning
论文作者
论文摘要
模型不合时宜的元学习(MAML)是最成功的元学习技术之一。它使用梯度下降来学习各种任务之间的共同点,从而使模型能够学习其自身参数的元定义,以使用少量标记的培训数据快速适应新任务。几次学习的关键挑战是任务不确定性。尽管可以从具有大量任务的元学习中获得强大的先验,但是由于训练数据集的数量通常太小,因此无法保证新任务的精确模型。在这项研究中,首先,在选择初始化参数的过程中,为特定于任务的学习者提出了新方法,以适应性地学习选择最小化新任务损失的初始化参数。然后,我们提出了两种改进的方法对元损失部分的改进方法:方法1通过比较损失差的差异来产生权重,以提高几个类别时的准确性,而方法2介绍了每个任务的同质性不确定性,以根据原始梯度下降来称重多个损失,以增强精确性提高准确性的能力,同时提高准确性的能力。与以前的基于梯度的元学习方法相比,我们的模型在回归任务和少量分类中的性能更好,并提高了模型在元测试集中的学习率和查询集的鲁棒性。
Model-Agnostic Meta-Learning (MAML) is one of the most successful meta-learning techniques for few-shot learning. It uses gradient descent to learn commonalities between various tasks, enabling the model to learn the meta-initialization of its own parameters to quickly adapt to new tasks using a small amount of labeled training data. A key challenge to few-shot learning is task uncertainty. Although a strong prior can be obtained from meta-learning with a large number of tasks, a precision model of the new task cannot be guaranteed because the volume of the training dataset is normally too small. In this study, first,in the process of choosing initialization parameters, the new method is proposed for task-specific learner adaptively learn to select initialization parameters that minimize the loss of new tasks. Then, we propose two improved methods for the meta-loss part: Method 1 generates weights by comparing meta-loss differences to improve the accuracy when there are few classes, and Method 2 introduces the homoscedastic uncertainty of each task to weigh multiple losses based on the original gradient descent,as a way to enhance the generalization ability to novel classes while ensuring accuracy improvement. Compared with previous gradient-based meta-learning methods, our model achieves better performance in regression tasks and few-shot classification and improves the robustness of the model to the learning rate and query sets in the meta-test set.