arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2102.04683stat.MLcs.LGmath.DS
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基于元学习的短时间序列Koopman谱分析

Meta-Learning for Koopman Spectral Analysis with Short Time-series

NTT Communication Science Laboratories, NTT Corporation(NTT公司NTT通信科学实验室);Institute of Mathematics for Industry, Kyushu University(九州大学产业数学研究所);Center for Advanced Intelligence Project, RIKEN(理化学研究所高级智能项目中心)

Tomoharu Iwata, Yoshinobu Kawahara

摘要:

Koopman谱分析在非线性动力系统中引起了人们的注意,因为我们可以通过将数据嵌入到Koopman空间中来分析具有线性区域的非线性动力系统。为了分析,我们需要找到合适的嵌入函数。虽然已经提出了几种基于神经网络的方法来学习嵌入函数,但是现有的方法需要长的时间序列来训练神经网络。该限制禁止在仅可用短时间序列的应用程序中执行库普曼光谱分析。在本文中,我们提出了一种元学习方法,通过利用从相关但不同的时间序列中学习到的知识,从看不见的短时间序列中估计嵌入函数。利用该方法,通过双向LSTM获取给定短时间序列的表示,以提取其属性。短时间序列的嵌入函数由依赖于时间序列表示的神经网络建模。通过跨多个时间序列共享LSTM和神经网络,我们可以从不同的时间序列中学习公共知识,同时使用时间序列表示对特定于时间序列的嵌入函数进行建模。我们的模型经过训练,使得使用情景训练框架的预期测试预测误差最小化。我们的实验表明,所提出的方法在特征值估计和未来预测方面比现有的方法取得了更好的性能。

英文摘要:

Koopman spectral analysis has attracted attention for nonlinear dynamical systems since we can analyze nonlinear dynamics with a linear regime by embedding data into a Koopman space by a nonlinear function. For the analysis, we need to find appropriate embedding functions. Although several neural network-based methods have been proposed for learning embedding functions, existing methods require long time-series for training neural networks. This limitation prohibits performing Koopman spectral analysis in applications where only short time-series are available. In this paper, we propose a meta-learning method for estimating embedding functions from unseen short time-series by exploiting knowledge learned from related but different time-series. With the proposed method, a representation of a given short time-series is obtained by a bidirectional LSTM for extracting its properties. The embedding function of the short time-series is modeled by a neural network that depends on the time-series representation. By sharing the LSTM and neural networks across multiple time-series, we can learn common knowledge from different time-series while modeling time-series-specific embedding functions with the time-series representation. Our model is trained such that the expected test prediction error is minimized with the episodic training framework. We experimentally demonstrate that the proposed method achieves better performance in terms of eigenvalue estimation and future prediction than existing methods.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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