Modeling of Emergency Supply Scheduling Problem Based on Reliability and Its Solution Algorithm under Variable Road Network after Sudden-Onset Disasters
Table 1
Model symbol description.
Represents the collector-distributor center of supplies at the upper level
Represents the set of collector-distributor center at the upper level
Represents the fixed cost of vehicles
Represents the convertible cost of vehicles on the way
Represents the set of all kinds of emergency supplies
Represents different types of emergency supplies
Represents damaged road segments
Represents the set of damaged road segments
Represents the total number of vehicles participating in supply scheduling
Represents the set of supply-needed disaster locations
Represents a certain supply-needed disaster location (k ∈ K)
Represents the set of transportation modes
Represents a certain mode of transportation (m ∈ M)
Represents a distribution center at the middle level
Represents the set of middle-level distribution centers (j ∈ J)
The quantity of emergency supplies c transported from the collector-distributor center i to the emergency distribution center j by means of transportation m
The amount of supply c provided by the collector-distributor center i (i ∈ I, c ∈ C)
The handling capacity/throughput of distribution center c
The rescue time spent on transporting supplies from the collector-distributor center i to the emergency distribution center j by means of transportation m
Transport emergency supplies c from the collector-distributor center i to the distribution center j by means of transportation m
The single transporting capability by means of transportation m for dispatching supplies from the collector-distributor center i to the distribution center j
The distance a vehicle travels at (i, j) segment
The transporting time spent on transporting supplies from the collector-distributor center i to the emergency distribution center j by means of transportation m
The urgency degree of emergency supply c
The time needed for distributing emergency supply c from collector-distributor i at the upper level to the distribution center j
The time needed for distributing emergency supply c from collector-distributor i to the middle level by means of transportation m
Variable 0-1. When vehicle m passes (j, k) segment, the variable is 1 or it becomes 0
The moment by vehicle m to drive out of the distribution center j
The latest demand-meeting time for supply c required by supply-needed location k
The time delayed when transporting supply c to supply-needed location k by means of transportation m. If the transportation is completed before dlkc, the δmkc will be 0
The operation time of vehicle m in segment (j, k). If (j, k)∈L, then tjkm = ∞
The quantity unmet of demand for supply c at supply-needed location k
Maximum load weight of vehicles at the lower level
The quantity of supply c transported to disaster-affected location k by means of transportation m
The time spent on transporting supply c to location k by means of transportation m. If no supply c is transported to location k, amkc = 0
The quantity of supply c needed for making urgent repair on road segment l
It is 1 when the decision is made to repair road segment l, or it becomes 0
