|
| Symbol | Description |
|
| Ť | Set of target locations |
| Ř | Set of charging stations |
| Ή | Set of base stations |
| Y | Set of all locations in the system |
| M | Number of target locations |
| C | Number of charging stations |
| S | drone’s maximum distance capacity |
| C | Demand of target location |
| G | Grid size |
| D | Total distance covered by all drones |
| x ij | Number of times drone travels from location i to j |
| I | Index used for locations |
| J | Index used for locations |
| Payload carried while leaving location i to j |
| W | Total payload capacity of the drone |
| e ij | drone’s energy level while leaving location i to j |
| E | Total energy capacity of the drone |
| d ij | Distance between location i and j |
| ρ 0 | Energy required for an empty drone to fly one unit distance |
| ρ | Additional energy needed for a drone to fly one unit distance |
| d min | Distance of the target that is closest to the base station |
| α | Ratio of distances |
| d Hti | Distance between the ith target and the base station |
| β i | Priority value of the ith target |
| μ i | Likelihood measure of ith target to be selected |
| P | First selected target of a group |
| Q | second selected target of a group |
| d Pi | Distance between the ith target and the first selected target P |
| d Qi | Distance between the ith target and the second selected target Q |
| Μ | Ratio of distances |
| ζ i | Likelihood measure of ith target to be selected |
| Λ | Ratio of distances |
| ξ i | Likelihood measure of ith group to be served first |
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