摘要
Missing values occur in bio-signal processing for various reasons,including technical problems or biological char-acteristics.These missing values are then either simply excluded or substituted with estimated values for further processing.When the missing signal values are estimated for electroencephalography (EEG) signals,an example where electrical signals arrive quickly and successively,rapid processing of high-speed data is required for immediate decision making.In this study,we propose an incremental expectation maximization principal component analysis (iEMPCA) method that automatically estimates missing values from multivariable EEG time series data without requiring a whole and complete data set.The proposed method solves the problem of a biased model,which inevitably results from simply removing incomplete data rather than estimating them,and thus reduces the loss of information by incorporating missing values in real time.By using an incremental approach,the proposed method alsominimizes memory usage and processing time of continuously arriving data.Experimental results show that the proposed method assigns more accurate missing values than previous methods.
Missing values occur in bio-signal processing for various reasons, including technical problems or biological characteristics. These missing values are then either simply excluded or substituted with estimated values for further processing. When the missing signal values are estimated for electroencephalography （EEG） signals, an example where electrical signals arrive quickly and successively, rapid processing of high-speed data is required for immediate decision making. In this study, we propose an incremental expectation maximization principal component analysis （iEMPCA） method that automatically estimates missing values from multivariable EEG time series data without requiring a whole and complete data set. The proposed method solves the problem of a biased model, which inevitably results from simply removing incomplete data rather than estimating them, and thus reduces the loss of information by incorporating missing values in real time. By using an incremental approach, the proposed method also minimizes memory usage and processing time of continuously arriving data. Experimental results show that the proposed method assigns more accurate missing values than previous methods.
基金
supported by the Ministry of Knowledge Economy,Korea, under the Information Technology Research Center support program supervised by National IT Industry Promotion Agency (No.NIPA-2011-C1090-1111-0008)
the Special Research Program of Chonnam National University,2009
the LG Yonam Culture Foundation
