Stationary Subspace Analysis

  • Authors:
  • Paul Bünau;Frank C. Meinecke;Klaus-Robert Müller

  • Affiliations:
  • Machine Learning Group, CS Dept., TU Berlin, Germany;Machine Learning Group, CS Dept., TU Berlin, Germany;Machine Learning Group, CS Dept., TU Berlin, Germany

  • Venue:
  • ICA '09 Proceedings of the 8th International Conference on Independent Component Analysis and Signal Separation
  • Year:
  • 2009

Quantified Score

Hi-index 0.00

Visualization

Abstract

Non-stationarities are an ubiquitous phenomenon in time-series data, yet they pose a challenge to standard methodology: classification models and ICA components, for example, cannot be estimated reliably under distribution changes because the classic assumption of a stationary data generating process is violated. Conversely, understanding the nature of observed non-stationary behaviour often lies at the heart of a scientific question. To this end, we propose a novel unsupervised technique: Stationary Subspace Analysis (SSA). SSA decomposes a multi-variate time-series into a stationary and a non-stationary subspace. This factorization is a universal tool for furthering the understanding of non-stationary data. Moreover, we can robustify other methods by restricting them to the stationary subspace. We demonstrate the performance of our novel concept in simulations and present a real world application from Brain Computer Interfacing.