| 摘要 |
<p>A method and an apparatus for distinguishing systematic artefacts from noise involves localising functional noise in the vicinity of predicted functional peaks. The method is particularly relevant to detection and tracking of time-varying signals. An apparatus implementing such an application of the method comprises a detection system (50) which monitors each component of a multi-component periodic signal via its basis repeat unit: a cyclet, of periodicity τ. The signal is digitised and clocked through the system (50) in segments. A cyclet remover (62) subtracts predicted values of previously detected cyclets from the incoming signal segment to produce a residual signal. A cyclet detector (60) uses a sliding window procedure to detect further cyclets in this residual and to measure their amplitude profiles (b(τ) and periodicities (τ). A cyclet tracker (64) uses this residual to correct errors in the predicted cyclet values (b(τ), τ) and to predict (track) cyclet values appropriate to the next incoming signal segment. A track remover (66) monitors cyclets variations and removes sub-threshold cyclets from the tracking process.</p> |
