Ahamed Md Atik, Cheng Qiang
Department of Computer Science, University of Kentucky, Lexington, KY, USA.
Institute for Biomedical Informatics, University of Kentucky, Lexington, KY, USA.
Inf Fusion. 2025 Aug;120. doi: 10.1016/j.inffus.2025.103079. Epub 2025 Mar 20.
Multivariate time series classification (TSC) is critical for various applications in fields such as healthcare and finance. While various approaches for TSC have been explored, important properties of time series, such as shift equivariance and inversion invariance, are largely underexplored by existing works. To fill this gap, we propose a novel multi-view approach to capture patterns with properties like shift equivariance. Our method integrates diverse features, including spectral, temporal, local, and global features, to obtain rich, complementary contexts for TSC. We use continuous wavelet transform to capture time-frequency features that remain consistent even when the input is shifted in time. These features are fused with temporal convolutional or multilayer perceptron features to provide complex local and global contextual information. We utilize the Mamba state space model for efficient and scalable sequence modeling and capturing long-range dependencies in time series. Moreover, we introduce a new scanning scheme for Mamba, called tango scanning, to effectively model sequence relationships and leverage inversion invariance, thereby enhancing our model's generalization and robustness. Experiments on two sets of benchmark datasets (10+20 datasets) demonstrate our approach's effectiveness, achieving average accuracy improvements of 4.01-6.45% and 7.93% respectively, over leading TSC models such as TimesNet and TSLANet. The code is available at: https://drive.google.com/file/d/1fScmALgreb_sE9_P2kIsQCmt9SNxp7GP/view?usp=sharing.
多变量时间序列分类(TSC)对于医疗保健和金融等领域的各种应用至关重要。虽然已经探索了各种TSC方法,但时间序列的重要属性,如平移不变性和反转不变性,在现有工作中很大程度上未得到充分研究。为了填补这一空白,我们提出了一种新颖的多视图方法来捕获具有平移不变性等属性的模式。我们的方法整合了多种特征,包括频谱、时间、局部和全局特征,以获得丰富、互补的上下文用于TSC。我们使用连续小波变换来捕获即使输入在时间上发生偏移时仍保持一致的时频特征。这些特征与时间卷积或多层感知器特征融合,以提供复杂的局部和全局上下文信息。我们利用曼巴状态空间模型进行高效且可扩展的序列建模,并捕获时间序列中的长程依赖关系。此外,我们为曼巴引入了一种新的扫描方案,称为探戈扫描,以有效地建模序列关系并利用反转不变性,从而提高我们模型的泛化能力和鲁棒性。在两组基准数据集(10 + 20个数据集)上的实验证明了我们方法的有效性,分别比TimesNet和TSLANet等领先的TSC模型平均准确率提高了4.01 - 6.45%和7.93%。代码可在以下链接获取:https://drive.google.com/file/d/1fScmALgreb_sE9_P2kIsQCmt9SNxp7GP/view?usp=sharing 。