## 3 Results and Discussions
### The Scenario of Sensor Location for Optimum Monitoring and Control  
The installation of sensors that are based on variability would be ideal for the best environmental monitoring and management in a greenhouse. When there is more unpredictability in the environment, it would be desirable to have more sensors to monitor the circumstances, but this would raise the cost [50]. Ideally, sensors should be placed at varying heights as the crops grow, with the best positions being near the canopy for luminous intensity and CO\({}_{2}\) concentration. For temperature and humidity, sensor placement options include near the ground surface, halfway up the crop canopy, or both. Spatial locations of sensors should consider variability, including average, maximum, and minimum values, as well as the positions of components like windows, heaters, and coolers [51]. Potential sensor installation areas include the center and sides, where windows and entrance gates are located [52]. The specific location of sensors should reflect their intended purpose. Table 2 presents the results of a statistical analysis conducted on temperature and humidity variations within the CSG with crops and the CSG without crops. The aim was to assess whether the data measured at different sensor locations were statistically different. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Treatment**} & \multicolumn{2}{c}{**CSG with Crops**} & \multicolumn{2}{c}{**CSG without Crops**} \\ \cline{2-5}  & **Temperature** (\({}^{\circ}\)**C**) & **Humidity (\%)** & **Temperature** (\({}^{\circ}\)**C**) & **Humidity (\%)** \\ \hline T\({}_{1}\) & 11.950 \({}^{\circ}\) & 68.112 \({}^{\circ}\) & 18.783 \({}^{\circ}\) & 67.217 \({}^{\circ}\) \\ T\({}_{2}\) & 13.274 \({}^{\circ}\) & 64.196 \({}^{\circ}\) & 16.821 \({}^{\circ}\) & 65.837 \({}^{\circ}\) \\ T\({}_{3}\) & 14.002 \({}^{\circ}\) & 70.715 \({}^{\circ}\) & 15.483 \({}^{\circ}\) & 69.058 \({}^{\circ}\) \\ CV & 5.02 & 2.13 & 5.01 & 2.27 \\ LSD & 0.4587 & 1.0082 & 0.4752 & 1.0093 \\ Significance (\%) & *** & *** & *** & *** \\ \hline \hline \end{tabular}  
* a.b.c Different letters in the same column indicate different data levels (\(p\leq 0.05\)). T\({}_{1}\) = bottom layer, T\({}_{2}\) = middle layer, T\({}_{3}\) = top layer, CV = coefficient of variance (\(\%\)), Sig = level of significance (*** highly significant).  
\end{table} 
Table 2: Statistical analysis on the temperature and humidity variations within the CSG with and the CSG without crops. Figure 14: Wind speed and direction at the experimental site. To determine the significance, the Tukey HSD test was executed. The bar plots displayed in Figure 15 represent the distribution of temperature and humidity data recorded at each layer of the CSG with crops and without crops. Different letters are placed above the bar to indicate the significant differences (at \(p<0.05\)) according to the Tukey HSD test. These distinct letters signify that the groups exhibited statistical differences. The analysis revealed significant differences in temperatures and humidity measured at various locations for both the CSG with crops and the CSG without crops. These findings emphasize the importance of carefully selecting the optimal sensor location, as there may be seasonal differences in the internal greenhouse environment that affect the air temperature data used for internal environment control. The variability of ambient conditions within a controlled environment is crucial for sensor-based monitoring and control. This study focused on understanding how factors such as temperature, humidity, and light levels vary across different spatial locations, time periods, and vertical heights within these CSGs. Environmental conditions vary among various spatial locations within CSGs, including temperature, humidity, CO\({}_{2}\), and light conditions. Precisely measuring and managing these factors requires understanding these differences. Temporal variability involves changes over time in winter, including daily fluctuations.