Selection of time instants and intervals with Support Vector Regression for multivariate functional data

When continuously monitoring processes over time, data is collected along a whole period, from which only certain time instants and certain time intervals may play a crucial role in the data analysis. We develop a method that addresses the problem of selecting a finite and small set of short interva...

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Detalles Bibliográficos
Autores: Blanquero Bravo, Rafael, Carrizosa Priego, Emilio José, Jiménez Cordero, María Asunción, Martín Barragán, Belén
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/107836
Acceso en línea:https://hdl.handle.net/11441/107836
https://doi.org/10.1016/j.cor.2020.105050
Access Level:acceso abierto
Palabra clave:Machine learning
Functional regression
Support Vector Regression
Time interval selection
Descripción
Sumario:When continuously monitoring processes over time, data is collected along a whole period, from which only certain time instants and certain time intervals may play a crucial role in the data analysis. We develop a method that addresses the problem of selecting a finite and small set of short intervals (or instants) able to capture the information needed to predict a response variable from multivariate functional data using Support Vector Regression (SVR). In addition to improving interpretability, storage requirements, and monitoring cost, feature selection can potentially reduce overfitting by mitigating data autocorrelation. We propose a continuous optimization algorithm to fit the SVR parameters and select intervals and instants. Our approach takes advantage of the functional nature of the data by formulating a new bilevel optimization problem that integrates selection of intervals and instants, tuning of some key SVR parameters and fitting the SVR. We illustrate the usefulness of our proposal in some benchmark data sets.