| Abstract: |
The Korean Safety e-Report system handles various non-emergency safety-related civil complaints, including safety hazards, daily inconveniences, illegal parking, and traffic violations. The system accumulates large-scale user-generated complaint data; however, automatic analysis and classification remain challenging because complaint texts often contain noisy characteristics such as colloquial expressions, typographical errors, and incomplete sentence structures. This study analyzes the impact of hybrid semantic representation, which combines raw complaint texts with LLM-extracted object, status, and location information, on text clustering performance. Using 19,955 complaint records collected from the Korean Safety e-Report system in 2024, structured semantic information was generated using the Qwen2.5-7B-Instruct model. Clustering performance was then compared between raw-text representations and hybrid representations using various embedding models (TF-IDF, Ko-SBERT, BGE-M3, and Multilingual E5) and clustering algorithms (K-means, Agglomerative Clustering, HDBSCAN, and Spectral Clustering), evaluated with Silhouette Score (SS) and Calinski-Harabasz Index (CHI). Experimental results showed that the combination of BGE-M3 and HDBSCAN achieved the best performance, improving the SS from 0.567 to 0.579. TF-IDF-based experiments also showed performance improvements, indicating that LLM-derived semantic features can compensate for the limitations of sparse representations. Ko-SBERT showed limited performance improvements, whereas E5 showed performance degradation in some clustering settings. These findings suggest that compatibility between structured semantic information and embedding models is an important factor in clustering civil complaint texts and demonstrate the applicability of LLM-based semantic structuring in public complaint systems. |