通信学报 ›› 2024, Vol. 45 ›› Issue (1): 63-76.doi: 10.11959/j.issn.1000-436x.2024008

• 学术论文 • 上一篇    

基于全局-局部散度的多元时间序列无监督降维方法

李正欣1,2, 胡钢1, 张凤鸣1, 张晓丰1, 赵永梅1   

  1. 1 空军工程大学装备管理与无人机工程学院,陕西 西安 710051
    2 西北工业大学光电与智能研究院,陕西 西安 710072
  • 修回日期:2023-07-04 出版日期:2024-01-01 发布日期:2024-01-01
  • 作者简介:李正欣(1982- ),男,河南信阳人,博士,空军工程大学副教授、硕士生导师,主要研究方向为时间序列模式识别、数据挖掘与机器学习等
    胡钢(1998- ),男,江西九江人,空军工程大学博士生,主要研究方向为时间序列降维、数据挖掘与机器学习等
    张凤鸣(1963- ),男,重庆人,空军工程大学教授、博士生导师,主要研究方向为信息系统工程与智能决策
    张晓丰(1978- ),男,天津人,博士,空军工程大学副教授、硕士生导师,主要研究方向为信息系统工程与智能决策
    赵永梅(1982- ),女,陕西延安人,博士,空军工程大学副教授,主要研究方向为数据融合与补全、信息物理系统等
  • 基金资助:
    国家自然科学基金资助项目(62002381)

Unsupervised dimensionality reduction method for multivariate time series based on global and local scatter

Zhengxin LI1,2, Gang HU1, Fengming ZHANG1, Xiaofeng ZHANG1, Yongmei ZHAO1   

  1. 1 Equipment Management and Unmanned Aerial Vehicle Engineering School, Air Force Engineering University, Xi’an 710051, China
    2 School of Artificial Intelligence, Optics and Electronics (iOPEN), Northwestern Polytechnical University, Xi’an 710072, China
  • Revised:2023-07-04 Online:2024-01-01 Published:2024-01-01
  • Supported by:
    The National Natural Science Foundation of China(62002381)

摘要:

针对传统降维方法不能直接应用于多元时间序列,现有的多元时间序列降维方法难以在保证降维有效性的同时大幅降低数据维度的问题,提出一种基于全局-局部散度的多元时间序列无监督降维方法。首先,提出一种特征序列提取方法,提取多元时间序列协方差矩阵的上三角元素,将其组合为特征序列。然后,以“局部散度最小、全局散度最大”为基本思想,提出一种无监督降维模型,在保持局部近邻关系的同时,尽可能保留全局信息。将特征序列作为输入,最小化所有样本点邻域方差之和,最大化邻域中心点方差。求解模型得到的投影矩阵能够实现多元时间序列的降维。最后,在 20 组公开数据集上,对所提方法进行了实验验证。结果表明,所提方法能够在保证降维有效性的同时,较大幅度地降低多元时间序列的维度。

关键词: 多元时间序列, 图结构, 特征提取, 无监督降维, 分类精度

Abstract:

To solve the problem that the traditional dimensionality reduction methods cannot be directly applied to multivariate time series, and for the existing approaches, it is difficult to ensure the effectiveness of dimensionality reduction while significantly reducing the dimension, an unsupervised dimensionality reduction method of multivariate time series based on global and local scatter was proposed.Firstly, a feature series extraction method was proposed to extract the upper triangular elements of the co-variance matrix of each multivariate time series and combine them into a feature sequence.Then, based on the idea of “minimum local scatter and maximum global scatter,” an unsupervised dimensionality reduction model was presented, which preserved the global information as much as possible while maintaining the local nearest neighbor relationship.Using the feature sequence as the input, the sum of the neighborhood variances of all sample points was minimized, and the variance of all the neighborhood centroids were maximized.The projection matrix obtained by solving the proposed model could be used to perform the dimensionality reduction.Finally, the proposed method was evaluated with experiments on 20 public data sets.The results show that the proposed method can significantly reduce the dimension of multivariate time series, while ensuring the effectiveness of dimensionality reduction.

Key words: multivariate time series, graph structure, feature extraction, unsupervised dimensionality reduction, classification accuracy

中图分类号: 

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