Donglin Zhou

Hao Jiang, Guoquan Wang, Donglin Zhou et al.

Recent advances in Large Language Models (LLMs) have enhanced text-based recommendation by enriching traditional ID-based methods with semantic generalization capabilities. Text-based methods typically encode item textual information via prompt design and generate discrete semantic IDs through item tokenization. However, in domain-specific tasks such as local-life services, simply injecting location information into prompts fails to capture fine-grained spatial characteristics and real-world distance awareness among items. To address this, we propose LGSID, an LLM-Aligned Geographic Item Tokenization Framework for Local-life Recommendation. This framework consists of two key components: (1) RL-based Geographic LLM Alignment, and (2) Hierarchical Geographic Item Tokenization. In the RL-based alignment module, we initially train a list-wise reward model to capture real-world spatial relationships among items. We then introduce a novel G-DPO algorithm that uses pre-trained reward model to inject generalized spatial knowledge and collaborative signals into LLMs while preserving their semantic understanding. Furthermore, we propose a hierarchical geographic item tokenization strategy, where primary tokens are derived from discrete spatial and content attributes, and residual tokens are refined using the aligned LLM's geographic representation vectors. Extensive experiments on real-world Kuaishou industry datasets show that LGSID consistently outperforms state-of-the-art discriminative and generative recommendation models. Ablation studies, visualizations, and case studies further validate its effectiveness.

Fan Zuo, Donglin Zhou, Jingqin Gao et al.

Accurate, scalable traffic monitoring is critical for real-time and long-term transportation management, particularly during disruptions such as natural disasters, large construction projects, or major policy changes like New York City's first-in-the-nation congestion pricing program. However, widespread sensor deployment remains limited due to high installation, maintenance, and data management costs. While traffic cameras offer a cost-effective alternative, existing video analytics struggle with dynamic camera viewpoints and massive data volumes from large camera networks. This study presents an end-to-end AI-based framework leveraging existing traffic camera infrastructure for high-resolution, longitudinal analysis at scale. A fine-tuned YOLOv11 model, trained on localized urban scenes, extracts multimodal traffic density and classification metrics in real time. To address inconsistencies from non-stationary pan-tilt-zoom cameras, we introduce a novel graph-based viewpoint normalization method. A domain-specific large language model was also integrated to process massive data from a 24/7 video stream to generate frequent, automated summaries of evolving traffic patterns, a task far exceeding manual capabilities. We validated the system using over 9 million images from roughly 1,000 traffic cameras during the early rollout of NYC congestion pricing in 2025. Results show a 9% decline in weekday passenger vehicle density within the Congestion Relief Zone, early truck volume reductions with signs of rebound, and consistent increases in pedestrian and cyclist activity at corridor and zonal scales. Experiments showed that example-based prompts improved LLM's numerical accuracy and reduced hallucinations. These findings demonstrate the framework's potential as a practical, infrastructure-ready solution for large-scale, policy-relevant traffic monitoring with minimal human intervention.