[1]Energy Conversion Engineering Department Bandung State Polytechnic Bandung 40012 Indonesia;
[2]Faculty of Mathematics and Natural Sciences Sebelas Maret University Surakarta 57126 Indonesia;
[3]Economics and Business Faculty Sebelas Maret University Surakarta 57126 Indonesia;
[4]Medical Faculty Sebelas Maret University Surakarta 57126 Indonesia;