## 3 Methodology
### Data Processing  
During the five-week period of measurements, a total of 604,800 \(E_{i}\) values were recorded. Long-term daily measurements were started at 06:00 in the morning and ended at 06:00 the next day. Six-minute averages were used according to the ICNIRP's guidelines. Because samples were taken every 5 s, a total of 72 samples were taken in 6 min. The time-averaged electric field strength (\(E_{m}\)) was calculated as in (4).  
\[E_{m}=\frac{1}{72}\sum_{i=1}^{72}E_{(i+72(m-1);72m)},\ \ m=1,2,\ldots,8400 \tag{4}\]  
where \(m\) represents the total number of time-averaged data index.  
The \(E_{m}\) was reshaped to include the \(E_{m}\) samples (\(k\)) for each day (\(p\)) of the weeks (\(n\)) as given in (5).  
\[E_{m}\to E_{n,p,k},n=1,2,\ldots,5;\ p=1,2,\ldots,7;\ k=1,2,\ldots,240 \tag{5}\]  
The change in RF-EMF level for Monday, the first day of the measurements (\(E_{1,1,k}\)), is given in Figure 5 as an example of \(E_{n,p,k}\). As seen from the figure, the maximum RF-EMF level recorded is 2.04 V/m. This value is well below 21 V/m, which is the lowest limit value between 100 kHz-3 GHz determined by ICTA. The mean value of the RF-EMF level is 1.3716 V/m, and the standard deviation is 0.3381 V/m. Additionally, the RF-EMF values measured in the morning (between 06:00-07:00) and at night (between 24:00-06:00) are quite low compared to the noon hours. The RF-EMF value measured at noon (e.g., 2.04 V/m) is almost 2.5 times higher than the value measured in the morning (e.g., the minimum RF-EMF value measured at 0.81 V/m). Because the measurements were made at the OMU Kurupelit Campus (Samsun, Turkey), Figure 5 shows a significant decrease in the measured RF-EMF value after 17:30 when students start to leave the campus.  
The RF-EMF measurement results of each week (five weeks in total) are given in Figure 6. As can be concluded from the figure, there are differences in RF-EMF levels not only at different times of the day but also between working and nonworking days. The one-week-long measurement data show RF-EMF data starting at 06:00 on Monday morning and continuing until 06:00 on Monday morning the following week. The statistical evaluations of weekly measurements are given in Figure 7. In figure, red lines indicate the medians, the bottom and top edges of the blue boxes indicate the 25 th and 75 th percentiles, and red plus signs illustrate the outliers. The mean RF-EMF value for the first week is 1.2757 V/m, and the mean values for the second, third, fourth, and fifth weeks are 1.2513 V/m, 1.2849 V/m,  
Figure 5: Daily RF-EMF levels (for Monday).  
1.3880 V/m, and 1.1968 V/m, respectively. Additionally, the outliers in the data from the fifth week may be due to exams held on campus.  
The generalized cumulative distribution function of all five weeks' RF-EMF data is given in Figure 8. As can be seen from Figure 8, 50% of the measured RF-EMF values are below 1.2528 V/m, while they are lower than 1.6571 V/m for 90% of the measurement data.  
Figure 8: The generalized cumulative distribution function of five weeks’ RF-EMF data.  
Figure 6: Daily variation of RF-EMF levels for five weeks.  
Figure 7: Statistical analysis of weekly RF-EMF data.  
The relationships between the measured RF-EMF data on the same days in different weeks are presented in terms of correlation coefficients in Figure 9. It can be concluded from the figure that the RF-RMF levels measured on Wednesday and Thursday are highly correlated compared to the other days. The highest correlation between the days was calculated as 0.9543 on Thursday between the 4 th and 5 th weeks. The correlation values between Saturday and Sunday vary considerably compared to weekdays. This may be because there are specific activities on campus on certain weekends (e.g., exams, conferences).