## 3 Results
### Coverage Analysis of Appropriate Scope of Two-Dimensional Scale Combinations  
This paper analyzed the range of appropriate two-dimensional scale combinations in terms of coverage, specifically focusing on their applicability to different scale combinations of underground commercial streets. To enhance the feasibility of the study, the perception trend of two scale elements was examined by varying another scale element. The variable length (L) allowed for a comprehensive exploration of three-dimensional scale combinations. By determining the appropriate range of aspect ratio (L/D) for different heights (H), the corresponding lengths (L) for three widths (D) of underground commercial streets within this range could be identified. The perception appropriateness within this range reflected the coverage of the two-dimensional scale combinations. If a majority of the length perceptions and stability perceptions fell within the appropriate range of L/D, then this indicated good coverage. If some of the length perceptions and stability perceptions were within the appropriate range of L/D, then this suggested general coverage. However, if the length and stability perceptions did not fall within the appropriate range of L/D, then this indicated a lack of coverage. Firstly, the appropriate lengths (L) corresponding to the three widths (D) were obtained based on the appropriate range of aspect ratios (L/D) for five different heights (H). This information is presented in Table 9. Subsequently, a regression analysis was performed in SPSS, considering the scale combination changes and the quantified perception evaluation data from Experiment 1. The fitting curves for the six kinds of spatial perception were obtained and integrated into a single graph, creating an overall perception change graph. To further explore the coverage of different three-dimensional scale combination streets by the two-dimensional scale combination fit range, the overall perception change map was combined with the obtained length (L) fit range. This combined information is shown in Table 10, the shaded part indicates the range of suitability of the zone. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & & & & & \\ \cline{2-7}  & **H = 3.0 m** & **H = 3.5 m** & **H = 4.0 m** & **H = 4.5 m** & **H = 5.0 m** & **H = 3.0 m** \\ \hline width range & 0.9–1.3 & 1.0–1.4 & 1.1–1.4 & 1.2–1.6 & 0.9–1.3 & 1.0–1.4 \\ height range & 1.0–1.6 & 1.1–1.8 & 1.2–2.3 & 1.3–2.4 & 1.0–1.6 & 1.1–1.8 \\ openness range & 1.1–2.9 & 1.1–2.9 & 1.1–2.9 & 1.2–2.9 & 1.1–2.9 & 1.1–2.9 \\ width/height/openness range & 1.1–1.3 & 1.1–1.4 & 1.2–1.5 & 1.2–1.6 & 1.1–1.3 & 1.1–1.4 \\ the overall appropriate range & & & 1.2–1.3 & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Appropriate range of aspect ratio D/H. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{2}{c}{**L**} \\ \cline{2-4}  & **D = 3.3 m** & **D = 5.4 m** & **D = 8.7 m** \\ \hline H = 3.0 m & 30–47 & 50–77 & 80–124 \\ H = 3.5 m & 28–42 & 46–70 & 73–113 \\ H = 4.0 m & 27–38 & 45–63 & 72–100 \\ H = 4.5 m & 25–37 & 41–60 & 66–97 \\ H = 5.0 m & 23–33 & 38–54 & 60–87 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Graph of the overall perception curve corresponding to the appropriate length.