# Finding Optimal Stations Using Euclidean Distance and Adjustable Surrounding Sphere
## 4 Proposed Methods
### Euclidean Distance + Fixed Surrounding Sphere (ED + FSS)
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline
**Bangkok, Thailand** & **Sejong, Korea** & **Bonn, Germany** \\ \hline \hline COV: 89\% (+39\%) & COV: 91\% (+34\%) & COV: 62\% (+130\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Location of an additional station and resulting coverage percentages in Bangkok, Sejong, and Bonn. Figure 8: Plot of coverage percentage versus number of stations in Bangkok. enhance spatial coverage and proper confidence area. In setting up a network in the cities, such a method suggested a balance of station locations and achieved maximum spatial coverage. The stations are neither located close to the border, nor are they close together. However, they are evenly distributed over the city. These results indicated that if the city planner considers economic benefits and the investment costs for constructing a network, the proposed method can give an excellent. In adding stations in cities, the results showed an optimal for the next station and enhanced the spatial coverage. Our proposed method showed effectiveness for expanding the existing networks as well as setting up AQMN. In future work, we will consider the ratio of spatial coverage satisfaction versus confidence area as we mentioned in our experiment. We will modify our methods by changing strategies after achieving the spatial coverage to increase the overlapped regions of confidence areas. Moreover, we will integrate the historical pollution information, the city characteristics data, and land-use to find stations for better air pollution monitoring. Formal analysis, A.O. ; methodology, A.O., H.J. ; software, A.O. ; validation, H.J., K.C. ; investigation, A.O., H.J., writing-original draft preparation, A.O. ; writing-review & editing, A.O., H.J., K.C. ; supervision, H.J., K.C. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The authors declare no conflict of interest. ## References

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