## 4 Experimental Studies
### Results and Comparative Analysis  
The Full Time Series Sliding Search Method (FTSSSM) was used to obtain the correct window size. In order to scientifically compare the correctness of the new Monte Carlo Search Method (MCSM), FTSSSM experiments were carried out at the same time. The evaluation indexes of the calculation results of FTSSSM and MCSM included the running time of the program and the accuracy of the optimal window. We carried out the experiment according to the experimental platform and initial conditions in Section 4.2. The statistical information of the experimental calculation results is shown in Table 4. It can be seen from Table 4 that the optimal window size obtained from the FTSSSM experiments was between 8 and 18, and there were two or three optimal windows for DO and turbidity. With the increase of sampling scale, the accuracy of MCSM continued to improve, and the running time of the program continued to increase. When the sampling scale was 0.8\(n\), the optimal window accuracy of different water quality factors was between 67.5% and 85%. When the sampling scale was 0.5\(n\), the optimal window accuracy of different water quality factors was between 52.5% and 65%. In order to quantitatively analyze the improvement of the running time efficiency of MCSM, the running time of different sampling scales was selected and compared with that of FTSSSM experiments, and we calculated the rate of computation time increase. The rate of computation time increase was as follows:  
\[rr=\frac{t_{j}(n)-t_{j}(i)}{t_{j}(n)}\times 100\%,j\ from\ 5\ to\ 30 \tag{2}\]  
where \(rr\) is the rate of computation time increase, \(j\) is the number of windows (traverse calculation from 3 to 30), \(t_{j}(n)\) is the run-time of FTSSSM, and \(t_{j}(i)\) is the run-time of MCSM. \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline \multirow{2}{*}{**Water Factors**} & \multirow{2}{*}{**Sampling** **Period**} & **Time Series** & **Instrument** & **Mean Value** & **Standard** & **Coefficient of** \\  & & **Length** & **Accuracy** & **Value** & **Deviation** & **Variation** \\ \hline
**pH** & 1 h & 4723 & \(\pm 0.2\) pH & – & 8.29 & 0.73 & 0.09 \\ \hline \multirow{3}{*}{**Dissolved Oxygen**} & \multirow{3}{*}{1 h} & \multirow{3}{*}{4723} & \(\pm 0.2\) mg/L & \multirow{3}{*}{mg/L} & \multirow{3}{*}{10.43} & \multirow{3}{*}{3.02} & \multirow{3}{*}{0.29} \\  & & & \(\pm 0.6\) mg/L & & & & \\  & & & \(\pm 0.2\) mg/L & & & & \\ \hline
**Electronic Conductivity** & 1 h & 4723 & \(\pm 0.01\%\) & \(\mu\)5/cm & 261.00 & 53.90 & 0.21 \\ \hline \multirow{3}{*}{**Turbidity**} & \multirow{3}{*}{1 h} & \multirow{3}{*}{4723} & \(\pm 0.01\)NTU & \multirow{3}{*}{(Nephelometric & \multirow{3}{*}{99.20} & \multirow{3}{*}{118.51} & \multirow{3}{*}{1.19} \\  & & & & Turbidity Unit)} & & & \\ \hline
**Chlorophyll-a** & 1 h & 4723 & \(\pm 3\%\) & \(\mu\)g/L & 21.81 & 22.46 & 1.03 \\ \hline
**Algal Density** & 1 h & 4723 & \(\pm 3\%\) & cells/ml & 14,906 & 19,221 & 1.29 \\ \hline
**Permanganate Index** & 4 h & 1187 & \(\pm 5\%\) & mg/L & 8.80 & 4.86 & 0.55 \\ \hline
**Ammonia-Nitrogen** & 4 h & 1187 & \(\pm 10\%\) & mg/L & 0.12 & 0.17 & 1.42 \\ \hline
**Total Phosphorus** & 4 h & 1187 & \(\pm 10\%\) & mg/L & 0.17 & 0.11 & 0.65 \\ \hline
**Total Nitrogen** & 4 h & 1187 & \(\pm 10\%\) & mg/L & 1.37 & 0.65 & 0.47 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Information about the water quality factor data sources.