Preface A. Cardenas Tristan, J. Tetuko Sri Sumantyo, E. Haryono, R. Fitria Putri, D. Rahmawati Hizbaro and E. Wulanmei E3S Web Conf., 76 (2019) 00001 Published online: 15 January 2019 DOI: 10.1051/e3sconf/20197600001