期刊名称:International Journal of Computer Trends and Technology
电子版ISSN:2231-2803
出版年度:2013
卷号:4
期号:7-1
出版社:Seventh Sense Research Group
摘要:One important aspect of the data mining is found out the interesting periodic patterns from time series databases. One area of research in time series databases is periodicity detection. Time series prognosticating is the use of a model to presage future values based on previously observed values. Discovering periodic patterns from an entire time series has proven to be inadequate in applications where the periodic patterns occur only with in small segments of the time series. In this paper we proposed a couple of algorithms to extract interesting periodicities (Symbol, Sequence, and Segment) of whole time series or part of the time series. One algorithm utilizes Dynamic warping Technique and other one is suffix tree as a data structure. Couple of these algorithms has been successfully incontestable to work with replacement, Insertion, deletion, or a mixture of these types of noise. The algorithm is compared with DTW (Dynamic Time Warping) algorithm on different types of data size and periodicity on both real and synthetic data. The worst case complexity of the suffix tree noise resilient algorithm is O (n.k 2 ) where n is the maximum length of the periodic pattern. K is size of the portion (whole or subsection) of the time series.