arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2602.02601cs.SIcs.AI
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基于灾难推文的时空图因果发现:CaST

CaST: Causal Discovery via Spatio-Temporal Graphs in Disaster Tweets

Hieu Duong, Eugene Levin, Todd Gary, Long Nguyen

AI总结:

CaST通过整合语义、时空信息,利用大规模语言模型构建事件图,实现灾难推文中更稳健和可解释的因果发现。

摘要:

从社交媒体中理解现实事件之间的因果关系对于态势感知至关重要,但现有的因果发现方法往往忽视了语义、空间和时间背景之间的相互作用。我们提出了CaST:基于时空图的因果发现,这是一个统一的框架,用于灾难领域中的因果发现,它利用在灾难数据集上预训练的大型语言模型(LLMs)整合语义相似性和时空接近性。CaST为每个推文窗口构建一个事件图。从推文中提取的每个事件被表示为一个节点嵌入,该嵌入增强了其上下文语义、地理坐标和时间特征。这些事件节点随后连接形成一个时空事件图,该图通过多头图注意力网络(GAT)进行处理,以学习有向因果关系。我们构建了一个大约包含167,000条灾难相关推文的内部数据集,这些推文是在飓风哈维期间收集的,并按照MAVEN-ERE模式进行注释。实验结果表明,CaST在传统方法和最先进方法上均表现出优越的性能。消融研究进一步证实,结合空间和时间信号显著提高了召回率和训练期间的稳定性。总体而言,CaST表明,将时空推理整合到事件图中能够更稳健和可解释地发现与灾难相关的社交媒体文本中的因果关系。

英文摘要:

Understanding causality between real-world events from social media is essential for situational awareness, yet existing causal discovery methods often overlook the interplay between semantic, spatial, and temporal contexts. We propose CaST: Causal Discovery via Spatio-Temporal Graphs, a unified framework for causal discovery in disaster domain that integrates semantic similarity and spatio-temporal proximity using Large Language Models (LLMs) pretrained on disaster datasets. CaST constructs an event graph for each window of tweets. Each event extracted from tweets is represented as a node embedding enriched with its contextual semantics, geographic coordinates, and temporal features. These event nodes are then connected to form a spatio-temporal event graph, which is processed using a multi-head Graph Attention Network (GAT) \cite{gat} to learn directed causal relationships. We construct an in-house dataset of approximately 167K disaster-related tweets collected during Hurricane Harvey and annotated following the MAVEN-ERE schema. Experimental results show that CaST achieves superior performance over both traditional and state-of-the-art methods. Ablation studies further confirm that incorporating spatial and temporal signals substantially improves both recall and stability during training. Overall, CaST demonstrates that integrating spatio-temporal reasoning into event graphs enables more robust and interpretable causal discovery in disaster-related social media text.

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