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从子样本数据中发现时间因果关系

Discovering Temporal Causal Relations from Subsampled Data
课程网址: http://videolectures.net/icml2015_zhang_subsampled_data/  
主讲教师: Kun Zhang
开课单位: 马克斯普朗克智能系统研究所
开课时间: 2015-12-05
课程语种: 英语
中文简介:
格兰杰因果分析一直是包括神经科学和经济学在内的各个领域对时间序列进行因果分析的重要工具,最近它被扩展到包括时间序列之间的瞬时效应,以解释残差中的同时相关性。在本文中,我们假设真实因果频率下的时间序列遵循向量自回归模型。我们表明,当数据分辨率由于二次采样而变低时,原始的格兰杰因果分析和扩展的格兰杰分析都无法发现潜在的因果关系。然后,我们的目标是回答以下问题:我们能否从二次采样数据中以正确的因果频率估计时间因果关系?传统上,这存在可识别性问题:在数据的高斯假设下,解决方案通常不是唯一的。然而,我们证明,如果噪声项是非高斯的,则高频数据的基础模型可以在温和条件下从二次采样数据中识别出来。然后,我们提出了一种期望最大化(EM)方法和一种变分推理方法,以从这些二次采样数据中恢复时间因果关系。报告了模拟数据和真实数据的实验结果,以说明所提出的方法的性能。
课程简介: Granger causal analysis has been an important tool for causal analysis for time series in various fields, including neuroscience and economics, and recently it has been extended to include instantaneous effects between the time series to explain the contemporaneous dependence in the residuals. In this paper, we assume that the time series at the true causal frequency follow the vector autoregressive model. We show that when the data resolution becomes lower due to subsampling, neither the original Granger causal analysis nor the extended one is able to discover the underlying causal relations. We then aim to answer the following question: can we estimate the temporal causal relations at the right causal frequency from the subsampled data? Traditionally this suffers from the identifiability problems: under the Gaussianity assumption of the data, the solutions are generally not unique. We prove that, however, if the noise terms are non-Gaussian, the underlying model for the high frequency data is identifiable from subsampled data under mild conditions. We then propose an Expectation-Maximization (EM) approach and a variational inference approach to recover temporal causal relations from such subsampled data. Experimental results on both simulated and real data are reported to illustrate the performance of the proposed approaches.
关 键 词: 因果分析; 瞬时效应; 模拟数据
课程来源: 视频讲座网
数据采集: 2022-12-19:chenjy
最后编审: 2022-12-19:chenjy
阅读次数: 11