Spectral density 15 noise 5 Brain 4 Electroencephalography 4 Technology: general issues 4 article 4 human 4 spectroscopy 4 feature extraction 3 Aerodynamics 2 Air traffic control 2 Analysis method 2 Artefact reduction 2 Dimensionality reduction 2 Extraction 2 Eye movements 2 Feature extraction 2 Features extraction 2 Humans 2 Impulse response 2 Independent component analysis 2 Independent components analysis 2 Noise 2 Performance 2 Power spectral density 2 Spectral density function 2 Threshold 2 Vigilance assessment 2 Vigilance levels 2 Wakes 2