model-agnostic meta-learning
Thursday, April 11, 2019 8:26:03 PM
Mauro

In effect, our method trains the model to be easy to fine-tune. During each training epoch, first a dataset is sampled and then mini-batches are sampled for updates. The training data contains multiple pairs of datasets: a support set and a test set. However, because the task-specific optimization can take more than one step. We expect a good meta-learning model capable of well adapting or generalizing to new tasks and new environments that have never been encountered during training time. The expectation is averaged over two data batches, ids 0 and 1 , for task. The model can include tendon wrapping as well as actuator activation states e.

This rapid parameter update can be achieved by its internal architecture or controlled by another meta-learner model. How the learner and the meta-learner are trained. How can we enable our artificial agents to acquire such versatility? The goal of meta-learning is to train a model on a variety of learning tasks, such that it can solve new learning tasks using only a small number of training samples. People can also use learned concepts in richer ways than conventional algorithms—for action, imagination, and explanation. We demonstrate that this approach leads to state-of-the-art performance on two few-shot image classification benchmarks, produces good results on few-shot regression, and accelerates fine-tuning for policy gradient reinforcement learning with neural network policies. The method is straightforward to implement and is based an adaptive estimates of lower-order moments of the gradients.

On the test data, we achieved top-1 and top-5 error rates of 37. Lower level models like those that are built on image classification, reinforcement learning tasks, etc. Prototypical Networks Prototypical Networks use an embedding function to encode each input into a -dimensional feature vector. The final prediction is the class of the support image with the highest probability. Our framework learns a network that maps a small labelled support set and an unlabelled example to its label, obviating the need for fine-tuning to adapt to new class types.

We propose an algorithm for meta-learning that is model-agnostic, in the sense that it is compatible with any model trained with gradient descent and applicable to a variety of different learning problems, including classification, regression, and reinforcement learning. Meta-learning for few-shot learning entails acquiring a prior over previous tasks and experiences, such that new tasks be learned from small amounts of data. Remaining an efficient gradient-based meta-learner, the method is also model-agnostic and simple to implement. In this method, there is one network the meta-learner which learns to update another network the learner so that the learner effectively learns the task. By using different kinds of metadata, like properties of the learning problem, algorithm properties like performance measures , or patterns previously derived from the data, it is possible to learn, select, alter or combine different learning algorithms to effectively solve a given learning problem. In our approach, the parameters of the model are explicitly trained such that a small number of gradient steps with a small amount of training data from a new task will produce good generalization performance on that task.

A model of student learning is then described, in which personal and situational factors are linked to performance by three main approaches to learning: deep, achieving, and surface. Then the model of the fourth category is learnt from 1 to 5 training examples, and is used for detecting new exemplars a set of test images. We demonstrate that this approach leads to state-of-the-art performance on a few-shot image classification benchmark, produces good results on few-shot regression, and accelerates fine-tuning for policy gradient reinforcement learning with neural network policies. Critiques of meta learning approaches bear a strong resemblance to the critique of , a possibly related problem. Prototypical networks learn a metric space in which classification can be performed by computing Euclidean distances to prototype representations of each class. The loss function is the negative log-likelihood:.

Please feel free to leave me a comment or send me an email about this if you have ideas. Lastly, it can be easily applied to a number of domains, including classification, regression, and reinforcement learning. Because in a few-shot learning task, the classifier has to make generalisation after every few examples from each class. There are many cache replacement algorithms and each of them could potentially replace the design here with better performance in different use cases. I begin this thesis by considering a simple number concept game as a concrete illustration of this ability. Visual learning depends on both the algorithms and the training material. Both of them only contain data points with labels belonging to the sampled label set ,.

In this paper we address the following question: Can we approximately sample from a Bayesian posterior distribution if we are only allowed to touch a small mini-batch of data-items for every sample we generate?. Model Components Disclaimer: Below you will find my annotations are different from those in the paper. Contact responses are computed via efficient new algorithms we have developed, based on the modern velocity-stepping approach which avoids the difficulties with spring-dampers. The method exhibits invariance to diagonal rescaling of the gradients by adapting to the geometry of the objective function. Similar to other metric-based models, the classifier output is defined as a sum of labels of support samples weighted by attention kernel - which should be proportional to the similarity between and. The main objective of this approach is to find model agnostic solutions. Meta-learning came into light when its techniques were put in to use for optimisation of hyperparameters, neural networks and reinforcement learning.

So that the model learns new skills and quickly adapts to the changing environments with finite training precedents. We propose a general purpose variational inference algorithm that forms a natural counterpart of gradient descent for optimization. In addition, a robust Bayesian meta-update mechanism with a new meta-loss prevents overfitting during meta-update. Rather it depends on a model designed specifically for fast learning — a model that updates its parameters rapidly with a few training steps. This means that it will only learn well if the bias matches the learning problem. Since each algorithm is deemed to work on a subset of problems, a combination is hoped to be more flexible and able to make good predictions.

It can achieve in a provably optimal way. However, a critical challenge in few-shot learning is task ambiguity: even when a powerful prior can be meta-learned from a large number of prior tasks, a small dataset for a new task can simply be too ambiguous to acquire a single model e. In other words, both refer to the same embedding network that learns an efficient embedding to reveal relationship between pairs of data points. First, there is a developmental trend. The hyper-parameters have intuitive interpretations and typically require little tuning. Find sources: — · · · · August 2010 Meta learning is a subfield of where automatic learning algorithms are applied on about machine learning experiments.

We close with a brief discussion of a number of additional issues surrounding the use of such algorithms, including what is known about their limiting behaviors a. We have already used the engine in a number of control applications. We provide an analysis showing that some simple design decisions can yield substantial improvements over recent approaches involving complicated architectural choices and meta-learning. This approach has been extensively studied for. The twin networks are identical, sharing the same weights and network parameters.