1. UCSD Health Department of Biomedical Informatics, University of California San Diego, La Jolla , California, USA
2. School of Biomedical Informatics, The University of Texas Health Science Center at Houston , Houston, Texas, USA
3. Luddy School of Informatics, Computing, and Engineering, Indiana University Bloomington , Bloomington, Indiana, USA
4. Department of Mathematics, Hanyang University , Seoul, Republic of Korea
5. Department of Computer Science, Hanyang University , Seoul, Republic of Korea
6. Division of Health Services Research & Development, Veteran Affairs San Diego Healthcare System , San Diego, California, USA