A development in terms of storage yard equipment is the capability
to remotely operate gantry cranes. Although ASCs are capable
of operating completely automated, when the system is to interact
with non-automated entities, it is common to perform interactions
in a semi-automated manner for safety reasons. In other words, a
crane operator either takes over the ASC to complete the transfer
or approves the movement for the ASC to continue (e.g., Kim,
2006b). In Section 4 we describe methods for MHE selection.