FAST QUERY METHODS OF FINDING SUBSEQUENCES OF SATISFIED CHANGES ON TIME SERIES
Changes in the value of time series data often represent the occurrence of events.The change query on time series data,that is,to find the subsequences within a certain length that meets a certain threshold of increase or decrease,can mine events and has important practical significance.Existing methods cannot efficiently solve this problem.To this end,a method based on segmentation and constructing a segmentation relationship graph is proposed.Experiments show that this method can still return results within 100 milliseconds under a million-length time series,and the storage overhead of the segmentation relationship graph is also small.For data sets with less fluctuation,the storage size can reach less than 30％of the original data set size.Moreover,two optimization methods are further proposed,which can reduce the storage overhead by about 50％on the original basis,and at the same time do not affect the query efficiency too much.
Time seriesChanges querySubsequence querySegmentation
国家科技期刊平台
NSTL
万方数据
