摘要： In real project,the useful signal usually shows as low-frequency signal,but noise(outlier)shows as highfrequency signal.Wavlet transform can maps 1-D signal into a 2-D time-scale plane,and the localisation of signal is described in different scales,so it

关键词: 数据库 数据挖掘 时序数据 小波变换 例外挖掘