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Full-Text Articles in Physical and Environmental Geography
Quasi‐Hidden Markov Model And Its Applications In Cluster Analysis Of Earthquake Catalogs, Zhengxiao Wu
Quasi‐Hidden Markov Model And Its Applications In Cluster Analysis Of Earthquake Catalogs, Zhengxiao Wu
Research Collection School of Economics
We identify a broad class of models, quasi-hidden Markov models (QHMMs), which include hidden Markov models (HMMs) as special cases. Applying the QHMM framework, this paper studies how an earthquake cluster propagates statistically. Two QHMMs are used to describe two different propagating patterns. The “mother-and-kids” model regards the first shock in an earthquake cluster as “mother” and the aftershocks as “kids,” which occur in a neighborhood centered by the mother. In the “domino” model, however, the next aftershock strikes in a neighborhood centered by the most recent previous earthquake in the cluster, and therefore aftershocks act like dominoes. As the …
A Cluster Identification Framework Illustrated By A Filtering Model For Earthquake Occurrences, Zhengxiao Wu
A Cluster Identification Framework Illustrated By A Filtering Model For Earthquake Occurrences, Zhengxiao Wu
Research Collection School of Economics
A general dynamical cluster identification framework including both modeling and computation is developed.The earthquake declustering problem is studied to demonstrate how this framework applies.A stochastic model is proposed for earthquake occurrences that considers the sequence of occurrencesas composed of two parts: earthquake clusters and single earthquakes. We suggest that earthquake clusterscontain a “mother quake” and her “offspring.” Applying the filtering techniques, we use the solution offiltering equations as criteria for declustering. A procedure for calculating maximum likelihood estimations(MLE’s) and the most likely cluster sequence is also presented.