Ziwei Liu
School of Data Science, City University of Hong Kong · Hong Kong, China · lziwei2-c@my.cityu.edu.hk
ziwliu8.github.io · GitHub · Google Scholar · ResearchGate
Ph.D. student in the AML Lab at the School of Data Science, City University of Hong Kong. My research focuses on Recommender Systems, Information Retrieval, and Large Language Models, with papers published or preprinted at top international AI conferences.
Education
City University of Hong Kong
Ph.D. in Data Science. Affiliation: AML Lab
City University of Hong Kong
Master of Engineering in Data Science. Supervisor: Prof. Zhao Xiangyu
Southeast University
Bachelor of Engineering in Robotics Engineering. Co-supervised by Prof. Gan Yahui and Prof. Li Jun. Excellent Graduation Project
Research Experience
Chinese University of Hong Kong (Shenzhen)
Research Assistant
Publications & Preprints
Conditional Memory Enhanced Item Representation for Generative Recommendation (ComeIR)
Preprint, arXiv, May 2026.
- Identifies bottlenecks in current decoupled two-stage generative recommendation frameworks and leverages engram memory for stronger GR input and decoding.
The Best of the Two Worlds: Harmonizing Semantic and Hash IDs for Sequential Recommendation (H2Rec)
Accepted by KDD'26 ADS Track, May 2026.
- Harmonizes semantic IDs with hash IDs to address collaborative overwhelming in sequential recommendation, with deployment at Red Book (Xiao Hong Shu) and reported commercial gains.
LLM-EDT: Large Language Model Enhanced Cross-domain Sequential Recommendation with Dual-phase Training
Accepted by SIGIR'26, April 2026.
- Proposes a dual-phase training paradigm and LLM-based item augmenter to address domain transition, imbalance, and rough profiling issues in cross-domain sequential recommendation.
SIGMA: Selected Gated Mamba for Sequential Recommendation
Accepted by AAAI'25, December 2024.
- Studies the application of Mamba structures to sequential recommendation and introduces a selective gated module with a lightweight GRU branch.
Tutorials
- KDD 2026: Tutorial on Generative Recommendation: Foundations and Frontiers. Project page. August 2026.
- KDD 2025: Large language model enhanced recommender systems: Taxonomy, trend, application and future. Project page. August 2025.
Honors and Awards
- AAAI 2025 Travel Award and Volunteer, January 2025.
- Silver Medal in Kaggle: LLM Prompt Recovery, Rank 44/2175, December 2024.
- Excellent Graduation Project, Southeast University, June 2023.
Academic Service
- Journal Reviewer: IEEE Transactions on Knowledge and Data Engineering (TKDE), ACM Transactions on Knowledge Discovery from Data (TKDD), ACM Transactions on Information Systems (TOIS).
- Program Committee / Reviewer: ACM MM 2026 Main Track and DB Track, SIGIR 2026, AAAI 2026 Main Track and AIA Track, SIGIR 2025, ACM RecSys 2025.