# Joint Deployment of Sensors and Chargers in Wireless
## 5 Simulation Evaluation
### Solution of the Charger Deployment
#### 5.3.2 Varying the Number of L\({}_{s}\)  
The accuracy of the GH and PSO solutions is verified by varying the number of \(L_{s}\) to improve discretization accuracy. The results in Figure 8 show that as the number of \(L_{s}\) increases, the number of deployed chargers decreases. Both the GH and PSO solutions based on the GHDSAE solution can always deploy fewer chargers than that of the GH and the PSO solutions based on the GHDS solution. In Figure 8a, the GHDSAE-based GH solution saves 16.82\(-\)25.81% (with an average of 21.20%) chargers than that of the GHDS-based GH solution. In Figure 8b, the GHDSAE-based GH solution saves 0.26-19.21% (with an average of 10.22%) less time than that of the GHDS-based GH solution. There is an inflection point at \(L_{s}=7\), and subsequent increases of \(L_{s}\) do not significantly reduce the number of chargers. In Figure 8c, the GHDSAE-based PSO solution saves 14.60-27.77% (with an average of 18.08%) more chargers than the GHDS-based PSO solution. In Figure 8d, the GHDSAE-based PSO solution saves 18.15-33.51% (with an average of 21.62%) less time than that of the GHDS-based PSO solution. An inflection point occurs at \(L_{s}=5\), and subsequent increases of \(L_{s}\) do not significantly reduce the number of chargers. In consequence, the aggregation effect of sensors can reduce the deployment of chargers at the expense of slightly incremental computing time. Likewise, both the PSO solutions based on the GHDSAE and the GHDS solutions can always deploy fewer chargers than that of GH solutions based on the GHDSAE and the GHDS solutions. In Figure 8a,c, the GHDS-based PSO solution saves 7.62-26.06% (with an average of 13.81%) more chargers than the GHDS-based GH solutions. The GHDSAE-based PSO solutions save 5.15-20.72% (with an average of 10.53%) more chargers than the GHDSAE-based GH solution. In Figure 8b,d, the GHDS-based PSO solution consumes 308.06\(-\)451.70% (with an average of 360.05%) more solving time than that of the GHDS-based GH solution, and the GHDSAE-based PSO solution consumes 276.72\(-\)354.08% (with an average of 301.20%) more solving time than that of the GHDS-based GH solution. In Figure 8c, the GHDSAE-based PSO solution saves 14.60-27.77% (with an average of 18.08%) more chargers than the GHDS-based PSO solution. In Figure 8d, the GHDSAE-based PSO solution saves 18.15-33.51% (with an average of 21.62%) less time than that of the GHDS-based PSO solution. In Figure 8e, the GHDSAE-based PSO solution saves 18.15-33.51% (with an average of 21.62%) less time than that of the GHDS-based PSO solution. An inflection point occurs at \(L_{s}=5\), and subsequent increases of \(L_{s}\) do not significantly reduce the number of chargers. In consequence, the aggregation effect of sensors can reduce the deployment of chargers at the expense of slightly incremental computing time. Likewise, both the PSO solutions based on the GHDSAE and the GHDS solutions can always deploy fewer chargers than that of GH solutions based on the GHDSAE and the GHDS solutions. In Figure 8a,c, the GHDS-based PSO solution saves 7.62-26.06% (with an average of 13.81%) more chargers than the GHDS-based GH solutions. The GHDSAE-based PSO solutions save 5.15-20.72% (with an average of 10.53%) more chargers than the GHDSAE-based GH solution. In Figure 8b,d, the GHDS-based PSO solution consumes 308.06\(-\)451.70% (with an average of 360.05%) more solving time than that of the GHDS-based GH solution,  
that of the GHDSAE-based GH solution. In summary, both the GH and PSO solutions are scalable as the discretization accuracy grows, and the PSO solution always outperforms the GH solution by deploying fewer chargers with the cost of acceptable calculation time expenses, and the aggregation effect of sensors can effectively reduce the deployment of chargers at the cost of slightly incremental computing time.