计算机应用 ›› 2016, Vol. 36 ›› Issue (6): 1639-1644.DOI: 10.11772/j.issn.1001-9081.2016.06.1639

• 大数据 • 上一篇    下一篇

弹性粗粒度动态弯曲时序相似性算法

陈明威1, 孙丽华1, 徐健锋1,2   

  1. 1. 南昌大学 软件学院, 南昌 330047;
    2. 同济大学 计算机科学与技术系, 上海 201804
  • 收稿日期:2015-11-10 修回日期:2016-01-18 出版日期:2016-06-10 发布日期:2016-06-08
  • 通讯作者: 陈明威
  • 作者简介:陈明威(1990-),男,河南安阳人,硕士研究生,主要研究方向:流数据挖掘、粒计算、数据分析、深度学习;孙丽华(1955-),女,江西南昌人,教授,博士,主要研究方向:流数据挖掘、粒计算、人工智能;徐健锋(1973-),男,江西南昌人,副教授,博士研究生,CCF会员,主要研究方向:流数据挖掘、粒计算、数据挖掘、深度学习。
  • 基金资助:
    国家自然科学基金资助项目(61070139,61273304)。

Temporal similarity algorithm of coarse-granularity based dynamic time warping

CHEN Mingwei1, SUN Lihua1, XU Jianfeng1,2   

  1. 1. Software College, Nanchang University, Nanchang Jiangxi 330047, China;
    2. Department of Computer Science and Technology, Tongji University, Shanghai 201804, China
  • Received:2015-11-10 Revised:2016-01-18 Online:2016-06-10 Published:2016-06-08
  • Supported by:
    This work is partially supported by the National Natural Science Foundation of China (61070139, 61273304).

摘要: 针对动态时间弯曲(DTW)算法在提高计算速度同时不能兼顾分类正确率的问题,提出了一种基于朴素粒计算思想的弹性粗粒度动态时间弯曲(CG-DTW)算法。首先,通过计算时序方差特征的方法来获取较优的时序粒度,用粒度特征代替原始序列;其次,再代入执行DTW算法,允许动态调整被比较时序粒间的弹性大小,从而获得相对最优的时序对应粒;最后,在对应最优粒的情况下计算DTW距离。同时引入下界函数的提前终止策略进一步提高CG-DTW算法效率。实验结果表明,所提算法要比经典算法运行速率提高21.4%左右,比降维策略算法正确率提高近32.3个百分点,尤其是长序列的分类,CG-DTW能够在保持正确率的情况下兼顾较高的运行效率。CG-DTW在实际应用中能适应不确定长序列分类。

关键词: 时序, 时间粒, 动态弯曲, 弹性

Abstract: The Dynamic Time Warping (DTW) algorithm cannot keep high classification accuracy while improving the computation speed. In order to solve the problem, a Coarse-Granularity based Dynamic Time Warping (CG-DTW) algorithm based on the idea of naive granular computing was proposed. First of all, the better temporal granularities were obtained by computing temporal variance features, and the original series were replaced by granularity features. Then, the relatively optimal corresponding temporal granularity was obtained by executing DTW with dynamically adjusting intergranular elasticity of granularities compared. Finally, the DTW distance was calculated in the case of the corresponding optimal granularity. During this progress, an early termination strategy of lower bound function was introduced for further improving the CG-DTW algorithm efficiency. The experimental results show that, the proposed algorithm was better than classical algorithm in running rate with increasing by about 21.4%, and better than dimension reduction strategy algorithm in accuracy with increasing by about 32.3 percentage points.Especially for the long time sequences classification, CG-DTW takes consideration into both high computing speed and better classification accuracy. In actual applications, CG-DTW can adapt to long time sequences classification with uncertain length.

Key words: time series, time grain, dynamic bending, elastic

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