- Article
Digital murals face degradation issues like fading and cracking, requiring objective and interpretable evaluation methods. To overcome the subjectivity and low efficiency of manual assessment, the study proposes an improved deep neural network that maps extracted features into four criteria: color quality, texture details, structural integrity, and degradation degree. Using the fuzzy analytic hierarchy process (FAHP) with triangular fuzzy numbers, the study computes global weights and obtains a comprehensive score via weighted linear aggregation. Experimental results show the network reduces root mean square error to 0.102 and mean absolute error to 0.089. Inter-class distance increases by 33.8%, and t-SNE visualization shows four quality clusters in four-corner separation. The comprehensive score monotonically decreases from 0.924 to 0.376 as degradation worsens, with texture details showing the most significant drop. The model effectively captures mural quality deterioration, aligning with real-world conservation cognition. This work provides an objective, quantitative, and automated tool to assist experts in quality screening and restoration prioritization for large-scale murals.
Symmetry
15 September 2026






![Energy of positive- and negative-parity states in the
Ca
40
nucleus as a function of J. The states identified with small green circles correspond to well-established spin–parity assignments, while the small red circles indicate states with uncertain spin–parity assignments. The brown lines connecting the circles represent electromagnetic transitions. All the states shown in the figure are taken from the compilation [59,60]. The black lines indicate rotational bands. In (a), the bands built on the 0+, 8+, and 3+ states, as well as the SD band, were previously proposed [9,59,60]. In (b), the 0− band was previously suggested [11,59,60]. The arranged bands are labeled according to the spin–parity (
J
π
) of their band head, with subscripts used to distinguish between bands with the same bandhead spin–parity.](https://mdpi-res.com/cdn-cgi/image/width=281%2Cheight=192/https://mdpi-res.com/symmetry/symmetry-18-01193/article_deploy/html/images/symmetry-18-01193-g001a-550.jpg)




