Time Series Data Augmentation as an Imbalanced Learning Problem

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Cerqueira, Vitor, Moniz, Nuno, Inácio, Ricardo, Soares, Carlos
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866929330094866432
author Cerqueira, Vitor
Moniz, Nuno
Inácio, Ricardo
Soares, Carlos
author_facet Cerqueira, Vitor
Moniz, Nuno
Inácio, Ricardo
Soares, Carlos
contents Recent state-of-the-art forecasting methods are trained on collections of time series. These methods, often referred to as global models, can capture common patterns in different time series to improve their generalization performance. However, they require large amounts of data that might not be readily available. Besides this, global models sometimes fail to capture relevant patterns unique to a particular time series. In these cases, data augmentation can be useful to increase the sample size of time series datasets. The main contribution of this work is a novel method for generating univariate time series synthetic samples. Our approach stems from the insight that the observations concerning a particular time series of interest represent only a small fraction of all observations. In this context, we frame the problem of training a forecasting model as an imbalanced learning task. Oversampling strategies are popular approaches used to deal with the imbalance problem in machine learning. We use these techniques to create synthetic time series observations and improve the accuracy of forecasting models. We carried out experiments using 7 different databases that contain a total of 5502 univariate time series. We found that the proposed solution outperforms both a global and a local model, thus providing a better trade-off between these two approaches.
format Preprint
id arxiv_https___arxiv_org_abs_2404_18537
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Time Series Data Augmentation as an Imbalanced Learning Problem
Cerqueira, Vitor
Moniz, Nuno
Inácio, Ricardo
Soares, Carlos
Machine Learning
Recent state-of-the-art forecasting methods are trained on collections of time series. These methods, often referred to as global models, can capture common patterns in different time series to improve their generalization performance. However, they require large amounts of data that might not be readily available. Besides this, global models sometimes fail to capture relevant patterns unique to a particular time series. In these cases, data augmentation can be useful to increase the sample size of time series datasets. The main contribution of this work is a novel method for generating univariate time series synthetic samples. Our approach stems from the insight that the observations concerning a particular time series of interest represent only a small fraction of all observations. In this context, we frame the problem of training a forecasting model as an imbalanced learning task. Oversampling strategies are popular approaches used to deal with the imbalance problem in machine learning. We use these techniques to create synthetic time series observations and improve the accuracy of forecasting models. We carried out experiments using 7 different databases that contain a total of 5502 univariate time series. We found that the proposed solution outperforms both a global and a local model, thus providing a better trade-off between these two approaches.
title Time Series Data Augmentation as an Imbalanced Learning Problem
topic Machine Learning
url https://arxiv.org/abs/2404.18537