“…For example, viral and disease transmission mechanisms ( Madar et al., 2004 ; Keeling and Eames, 2005 ; Meyers et al., 2005 ), internet and email network ( Newman et al., 2002 ; Yang and Yang, 2014 ), communication system ( Burgess, 1969 ; Cohen, 2010 ), and transportation networks ( Burghouwt, 2007 ; Zhang et al., 2016 ; Lowry, 2014 ). In recent years, it has been a popular research topic in maritime transportation as well ( Ducruet and Notteboom, 2012 ; Cheung et al., 2020 ; Hu et al., 2020a , 2020b ).…”