Inductive Learning
Understanding Supervised Learning In One Article
As you might know, supervised machine learning is one of the most commonly used and successful types of machine learning. In this article, we will describe supervised learning in more detail and explain several popular supervised learning algorithms. Remember that supervised learning is used whenever we want to predict a certain outcome from a given input, and we have examples of input/output pairs. We build a machine learning model from these input/output pairs, which comprise our training set. Our goal is to make accurate predictions for new, never-before-seen data. Supervised learning often requires human effort to build the training set, but afterwards automates and often speeds up an otherwise laborious or infeasible task. There are two major types of supervised machine learning problems, called classification and regression. In classification, the goal is to predict a class label, which is a choice from a predefined list of possibilities.
An Adjusted Nearest Neighbor Algorithm Maximizing the F-Measure from Imbalanced Data
Viola, Rémi, Emonet, Rémi, Habrard, Amaury, Metzler, Guillaume, Riou, Sébastien, Sebban, Marc
In this paper, we address the challenging problem of learning from imbalanced data using a Nearest-Neighbor (NN) algorithm. In this setting, the minority examples typically belong to the class of interest requiring the optimization of specific criteria, like the F-Measure. Based on simple geometrical ideas, we introduce an algorithm that reweights the distance between a query sample and any positive training example. This leads to a modification of the Voronoi regions and thus of the decision boundaries of the NN algorithm. We provide a theoretical justification about the weighting scheme needed to reduce the False Negative rate while controlling the number of False Positives. We perform an extensive experimental study on many public imbalanced datasets, but also on large scale non public data from the French Ministry of Economy and Finance on a tax fraud detection task, showing that our method is very effective and, interestingly, yields the best performance when combined with state of the art sampling methods.
Smaller, faster, cheaper, lighter: Introducing DistilBERT, a distilled version of BERT
At Hugging Face, we experienced first-hand the growing popularity of these models as our NLP library -- which encapsulates most of them -- got installed more than 400,000 times in just a few months. However, as these models were reaching a larger NLP community, an important and challenging question started to emerge. How should we put these monsters in production? How can we use such large models under low latency constraints? Do we need (costly) GPU servers to serve at scale?
Solve fraud detection problem by using graph based learning methods
Tran, Loc, Tran, Tuan, Tran, Linh, Mai, An
Preprint submitted to RGN Publications on 21 /5/2018 Abstract The credit cards' fraud transactions detection is the important problem in machine learning field. To detect the credit cards' fraud transactions help reduce the significant loss of the credit cards' holders and the banks. To detect the credit cards' fraud transactions, data scientists normally employ the un - supervised learning techniques and supervised learning technique. In this paper, we employ the graph p - Laplacian based semi - supervised learning methods combi ned with the under - sampling technique such as Cluster Centroids to solve the credit cards' fraud transactions detection problem. Experimental results show that that the graph p - Laplacian semi - supervised learning method s outper form the current state of art graph Laplacian based semi - supervised learning method ( p 2). 2010 AMS Classi fi cation: 05C85 Keywords and phrases: graph p - Laplacian, credit card, fraud detection, semi - supervised learning Article type: Research article 1 Introduction While purchasing online, the transactions can be done by using credit cards that are issued by the bank.
An Empirical Comparison on Imitation Learning and Reinforcement Learning for Paraphrase Generation
Generating paraphrases from given sentences involves decoding words step by step from a large vocabulary. To learn a decoder, supervised learning which maximizes the likelihood of tokens always suffers from the exposure bias. Although both reinforcement learning (RL) and imitation learning (IL) have been widely used to alleviate the bias, the lack of direct comparison leads to only a partial image on their benefits. In this work, we present an empirical study on how RL and IL can help boost the performance of generating paraphrases, with the pointer-generator as a base model. Experiments on the benchmark datasets show that (1) imitation learning is constantly better than reinforcement learning; and (2) the pointer-generator models with imitation learning outperform the state-of-the-art methods with a large margin.
Managed Spot Training: Save Up to 90% On Your Amazon SageMaker Training Jobs Amazon Web Services
Amazon SageMaker is a fully-managed, modular machine learning (ML) service that enables developers and data scientists to easily build, train, and deploy models at any scale. With a choice of using built-in algorithms, bringing your own, or choosing from algorithms available in AWS Marketplace, it's never been easier and faster to get ML models from experimentation to scale-out production. One of the key benefits of Amazon SageMaker is that it frees you of any infrastructure management, no matter the scale you're working at. For instance, instead of having to set up and manage complex training clusters, you simply tell Amazon SageMaker which Amazon Elastic Compute Cloud (EC2) instance type to use, and how many you need: the appropriate instances are then created on-demand, configured, and terminated automatically once the training job is complete. As customers have quickly understood, this means that they will never pay for idle training instances, a simple way to keep costs under control.
Few-shot Learning with Deep Triplet Networks for Brain Imaging Modality Recognition
Puch, Santi, Sánchez, Irina, Rowe, Matt
Image modality recognition is essential for efficient imaging workflows in current clinical environments, where multiple imaging modalities are used to better comprehend complex diseases. Emerging biomarkers from novel, rare modalities are being developed to aid in such understanding, however the availability of these images is often limited. This scenario raises the necessity of recognising new imaging modalities without them being collected and annotated in large amounts. In this work, we present a few-shot learning model for limited training examples based on Deep Triplet Networks. We show that the proposed model is more accurate in distinguishing different modalities than a traditional Convolutional Neural Network classifier when limited samples are available. Furthermore, we evaluate the performance of both classifiers when presented with noisy samples and provide an initial inspection of how the proposed model can incorporate measures of uncertainty to be more robust against out-of-sample examples.
Improvability Through Semi-Supervised Learning: A Survey of Theoretical Results
Semi-supervised learning is a setting in which one has labeled and unlabeled data available. In this survey we explore different types of theoretical results when one uses unlabeled data in classification and regression tasks. Most methods that use unlabeled data rely on certain assumptions about the data distribution. When those assumptions are not met in reality, including unlabeled data may actually decrease performance. Studying such methods, it therefore is particularly important to have an understanding of the underlying theory. In this review we gather results about the possible gains one can achieve when using semi-supervised learning as well as results about the limits of such methods. More precisely, this review collects the answers to the following questions: What are, in terms of improving supervised methods, the limits of semi-supervised learning? What are the assumptions of different methods? What can we achieve if the assumptions are true? Finally, we also discuss the biggest bottleneck of semi-supervised learning, namely the assumptions they make.
Semi-supervised Learning for Word Sense Disambiguation
This work is a study of the impact of multiple aspects in a classic unsupervised word sense disambiguation algorithm. We identify relevant factors in a decision rule algorithm, including the initial labeling of examples, the formalization of the rule confidence, and the criteria for accepting a decision rule. Some of these factors are only implicitly considered in the original literature. We then propose a lightly supervised version of the algorithm, and employ a pseudo-word-based strategy to evaluate the impact of these factors. The obtained performances are comparable with those of highly optimized formulations of the word sense disambiguation method.
Multi-passage BERT: A Globally Normalized BERT Model for Open-domain Question Answering
Wang, Zhiguo, Ng, Patrick, Ma, Xiaofei, Nallapati, Ramesh, Xiang, Bing
BERT model has been successfully applied to open-domain QA tasks. However, previous work trains BERT by viewing passages corresponding to the same question as independent training instances, which may cause incomparable scores for answers from different passages. To tackle this issue, we propose a multi-passage BERT model to globally normalize answer scores across all passages of the same question, and this change enables our QA model find better answers by utilizing more passages. In addition, we find that splitting articles into passages with the length of 100 words by sliding window improves performance by 4%. By leveraging a passage ranker to select high-quality passages, multi-passage BERT gains additional 2%. Experiments on four standard benchmarks showed that our multi-passage BERT outperforms all state-of-the-art models on all benchmarks.