The Optimization Model of Earthquake Emergency Supplies Collecting with the Limited Period and Double-Level Multihub

Table 7

Collecting time from .

	0.8	0.6	1.5	0.9
	1	0.7	2	1.3
	2	0.8	1.5	1.4

Note: set the average transit time as 1 for each emergency supplies distribution center during cycle .