Hi🙋! I am a PhD student at the Guanghua School of Management (GSM), Peking University. My research interest focuses on the interface between Operations Management (OM)/ Operations Research (OR) and AI.

📝 Publications

Working papers

• LLM-Inspired Pretrain-Then-Finetune for Small-Data, Large-Scale Optimization. [SSRN][arxiv]

  Zishi Zhang, Jinhui Han, Ming Hu, Yijie Peng

• Nonparametric Bayesian Optimization for General Rewards. [arxiv]

  Zishi Zhang, Tao Ren, Yijie Peng

• Sample-Efficient “Clustering and Conquer” Procedures for Parallel Large-Scale Ranking and Selection. [arxiv]

  Zishi Zhang, Yijie Peng

Conference papers

* indicates equal contribution.

• Half-order Fine-Tuning for Diffusion Model: A Recursive Likelihood Ratio Optimizer. ICLR 2026 Oral🔥🔥 Tao Ren, Zishi Zhang*, Zehao Li, Jingyang Jiang, Shentao Qin, Guanghao Li, Yan Li, Yi Zheng, Xinping Li, Min Zhan, Yijie Peng.
• Exploring and Exploiting Model Uncertainty in Bayesian Optimization. NeurIPS 2025. Zishi Zhang, Tao Ren, Yijie Peng.
• FLOPS: Forward Learning with OPtimal Sampling. ICLR 2025. Tao Ren, Zishi Zhang*, Jinyang Jiang, Guanghao Li, Zeliang Zhang, Mingqian Feng, Yijie Peng.
• Dynamic Assortment Optimization in Live-Streaming Sales. WSC 2024. Zishi Zhang, Haidong Li, Ying Liu, Yijie Peng
• RiskPO: Risk-based Policy Optimization with Verifiable Reward for LLM Post-Training. ICLR 2026. Tao Ren, Jinyang Jiang, Hui Yang, Wan Tian, Minhao Zou, Guanghao Li, Zishi Zhang, Qinghao Wang, Shentao Qin, Yanjun Zhao, Rui Tao, Hui Shao, Yijie Peng  

🏛️ Talk

• Phd Colloquium. Winter Simulation Conference 2023. San Antonio, Texas.
• Large-scale simulation optimization. INFORMS Annual Meeting 2024. Seattle, Washington.
• AI, Optimization, and Platform Decisions. POMS-HK 2026. Shen Zhen, China.