分段聚合近似和数值导数的动态时间弯曲方法

针对动态弯曲方法对时间序列数据相似性度量的质量和效率的局限性,本文提出一种基于分段聚合近似和数值导数的动态时间弯曲方法。该方法通过分段聚合近似将时间序列数据进行有效地降维,再结合数值导数对降维后的特征序列构建新特征序列,并且设计符合该特征序列相似性度量方法。实验结果分析表明,与传统动态弯曲方法相比,新方法具有较好的度量质量,能在时间序列数据挖掘中得到较好的分类效果,且在低维空间具有较高的分类效率,具有一定的优越性。
Dynamic time warping (DTW) is often used to measure the similarity of time series data; however, it has efficiency and quality limitations. In this study, a novel DTW method combining piecewise aggregate approximation (PAA) and derivatives is proposed to measure the similarity of time series. The dimensionality of the time series data was effectively reduced by PAA, and the feature sequence was transformed into new sequences by combining the numerical derivatives after the dimensionality reduction. Furthermore, the DTW design corresponded to the similarity measurement method of the feature sequence. The experimental results demonstrate that the proposed method is superior because it has better measurement quality, obtains a better classification effect in time series data mining, and has high efficiency in lower dimensional spaces