Text this: Quasi‐hidden Markov model and its applications in cluster analysis of earthquake catalogs

  _  __     ___      _____     ______    _____   
 | |/ //   / _ \\   |__  //   /_   _//  / ____|| 
 | ' //   / //\ \\    / //     -| ||-  / //---`' 
 | . \\  |  ___  ||  / //__    _| ||_  \ \\___   
 |_|\_\\ |_||  |_|| /_____||  /_____//  \_____|| 
 `-` --` `-`   `-`  `-----`   `-----`    `----`