between disposal node and generation node (make sure every
generation node could connect to at least one disposal node),
Gollowitzer and Ljubic (2011) ´ used mixed integer programming
model and denoted each node (disposal node and
generation node) as a node in a mathematical tree to attain
the optimal configuration solution; Church and Arfinkel (Zografos
and Samara, 1989) introduced in integrated model, which gave
an emphasis on simultaneously enlarging the distance between
integrated disposal center and residential area while minimizing
transportation cost