URBAN-PROTOS: Discrete Semantic Prototypes for Cross-City Region Representation Learning

Zihang Xu, Xinshun Feng, Haozhi Xie, Yi Qiao, Liangzhe Han, Leilei Sun


Abstract
Urban region representation learning plays a fundamental role in urban computing, providing compact embeddings that support a wide range of downstream analytical tasks. Existing methods are developed under a single-city setting and rely on continuous vector representations learned from city-specific spatiotemporal data. Learning transferable and semantically meaningful region representations in cross-city scenarios remains a significant challenge. In this paper, we propose URBAN-PROTOS, a two-stage framework for cross-city learning of urban region representations. We first abstract multi-city mobility data into discrete Urban Prototypes, which capture city-invariant spatiotemporal regularities from localized heterogeneous contexts. These prototypes serve as shared semantic units across cities and are further integrated into the semantic space of large language models through a prototype-guided alignment mechanism. Extensive experiments conducted demonstrate that URBAN-PROTOS consistently outperforms existing methods in cross-city transfer settings, while maintaining strong performance in single-city evaluations. Further analyses show that the learned region embeddings encode deep semantic regularities shared across cities, providing robust support for cross-city generalization.
Anthology ID:
2026.findings-emnlp.1373
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
29220–29235
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1373/
DOI:
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Cite (ACL):
Zihang Xu, Xinshun Feng, Haozhi Xie, Yi Qiao, Liangzhe Han, and Leilei Sun. 2026. URBAN-PROTOS: Discrete Semantic Prototypes for Cross-City Region Representation Learning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 29220–29235, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
URBAN-PROTOS: Discrete Semantic Prototypes for Cross-City Region Representation Learning (Xu et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1373.pdf