论文标题
灵活的多元时空鹰派恐怖主义过程模型
Flexible multivariate spatio-temporal Hawkes process models of terrorism
论文作者
论文摘要
我们开发灵活的多元时空鹰队工艺模型来分析恐怖主义模式。点过程方法的先前应用在政治暴力数据中主要利用颞鹰工艺模型，从而忽略了这些攻击模式中的空间变化。这限制了可以从这些模型中学到的东西，因为任何有效的反恐策略都需要在何时何地发生攻击的情况下进行知识。即使是关于时空鹰队过程的现有工作也对不适合恐怖主义数据的触发功能施加了限制。因此，我们大大概括了时空触发函数的结构，从而允许非分离性，非阶段性和交叉触发性（即跨组）。为了证明我们的模型的实用性，我们分析了两个现实世界恐怖主义数据的样本：阿富汗（2002-2013）进行单变量分析和尼日利亚（2009- 2017年）进行双变量分析。这两项研究共同表明，我们的模型优于标准霍克斯工艺模型，在整体模型拟合中赢得了广泛使用的替代方案，并揭示了通过构造在这些模型中掩盖的时空模式（例如，随着时间的推移，交叉触发的分散体增加）。
We develop flexible multivariate spatio-temporal Hawkes process models to analyze patterns of terrorism. Previous applications of point process methods to political violence data mainly utilize temporal Hawkes process models, neglecting spatial variation in these attack patterns. This limits what can be learned from these models as any effective counter-terrorism strategy requires knowledge on both when and where attacks are likely to occur. Even the existing work on spatio-temporal Hawkes processes imposes restrictions on the triggering function that are not well-suited for terrorism data. Therefore, we generalize the structure of the spatio-temporal triggering function considerably, allowing for nonseprability, nonstatitionarity, and cross-triggering (i.e., across the groups). To demonstrate the utility of our models, we analyze two samples of real-world terrorism data: Afghanistan (2002-2013) for univariate analysis and Nigeria (2009-2017) for bivariate analysis. Jointly, these two studies demonstrate that our models outperform standard Hawkes process models, besting widely-used alternatives in overall model fit and revealing spatio-temporal patterns that are, by construction, masked in these models (e.g., increasing dispersion in cross-triggering over time).
