Zhiyi Shi

I am a first-year PhD student in Computer Science at University of Illinois Urbana-Champaign (UIUC), co-advised by Prof. Jimeng Sun and Prof. Quanzheng Li from Harvard MGH.

Prior to that, I received my Master's Degree from Carnegie Mellon University and my Bachelor's Degree from Southeast University.

My research interests include Agentic AI, RL, Parameter Efficient Fine-Tuning.

I am actively seeking Summer 2026 Internship!

Email: zhiyis3 [AT] illinois [DOT] edu

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News

  • 2026-01: One paper on Low-Rank Adaptation is accepted by IEEE TPAMI!
  • 2025-12: Our paper "Adaptation of Agentic AI" is now on arXiv!
  • 2025-08: I joined UIUC as a PhD student!
  • 2025-07: One paper on Multimodal Model Editing is accepted by COLM 2025.
  • 2025-06: One paper on Low-Rank Adaptation is accepted by ICCV 2025.
  • 2025-01: One paper on Low-Rank Adaptation is accepted by ICLR 2025.
  • 2024-06: I joined Harvard SEAS as a Researcher!
  • 2024-05: I graduated from CMU!
  • 2024-05: Two papers are accepted by MICCAI 2024.
  • Selected Publications [ Full List ]

    (*Equal Contribution)

    dise Adaptation of Agentic AI
    Pengcheng Jiang*, Jiacheng Lin*, Zhiyi Shi*, Heng Ji, Yejin Choi, Dawn Song, Jimeng Sun, Jiawei Han
    [Arxiv] [Repo]

    This paper provides a comprehensive framework for Agentic AI adaptation, categorizing how systems evolve to handle complex tasks. It introduces a unified taxonomy that distinguishes between Agent Adaptation (refining the model's internal reasoning/planning) and Tool Adaptation (optimizing external components like APIs and memory). By analyzing trade-offs in cost, modularity, and generalization, the work offers a practical roadmap for building more reliable and autonomous AI agents.

    dise Task-Specific Directions: Definition, Exploration, and Utilization in Parameter Efficient Fine-Tuning
    Chongjie Si*, Zhiyi Shi*, Shifan Zhang, Xiaokang Yang, Hanspeter Pfister, Wei Shen
    IEEE Transactions on Pattern Analysis and Machine Intelligence (IEEE TPAMI), 2025
    [Paper] [Arxiv] [Code]

    We study task-specific directions (TSDs) as the key subspace that drives performance gains in parameter-efficient fine-tuning, and propose a unified framework to define, analyze, and utilize these directions in PEFT. Building on this insight, we introduce LoRA-Dash and LoRA-Init, and further combine them into LoRA-TSD, achieving consistent and significant improvements over standard LoRA across extensive experiments.

    dise DualEdit: Dual Editing for Knowledge Updating in Vision-Language Models
    Zhiyi Shi*, Binjie Wang*, Chongjie Si, Yichen Wu, Junsik Kim, Hanspeter Pfister
    Conference on Language Modeling (COLM), 2025
    [Paper] [Arxiv] [Code]

    DualEdit edits both textual and visual modalities in vision-language models at their most sensitive layers. A gating mechanism in the textual modality enables knowledge updates without harming the model's original abilities.

    dise Unleashing the power of task-specific directions in parameter efficient fine-tuning
    Chongjie Si*, Zhiyi Shi*, Shifan Zhang, Xiaokang Yang, Hanspeter Pfister, Wei Shen
    International Conference on Learning Representations (ICLR), 2025
    [Paper] [Arxiv] [Code]

    We propose LoRA-Dash, a framework that leverages task-specific directions (TSDs) to maximize fine-tuning efficiency and improve task performance.

    dise Generalized Tensor-based Parameter-Efficient Fine-Tuning via Lie Group Transformations
    Chongjie Si, Zhiyi Shi, Xuehui Wang, Yichen Xiao, Xiaokang Yang, Wei Shen
    International Conference on Computer Vision (ICCV), 2025
    [Arxiv] [Code]

    We propose a generalization of matrix-based PEFT to higher-dimensional parameter spaces using Lie group modeling, ensuring structure-preserving updates and demonstrating improved performance across vision and language tasks.

    dise MoRA: LoRA Guided Multi-modal Disease Diagnosis with Missing Modality
    Zhiyi Shi, Junsik Kim, Wanhua Li, Yicong Li, Hanspeter Pfister
    Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI), 2024
    [Paper] [Arxiv] [Code]

    MoRA is a computationally efficient method for multi-modal disease diagnosis that adapts to missing modalities using modality-specific low-rank projections.

    Professional Activities

  • Reviewer, Conference on Neural Information Processing Systems (NeurIPS), 2025.
  • Reviewer, IEEE Transactions on Artificial Intelligence.
  • Reviewer, IEEE Transactions on Medical Imaging.
  • Reviewer, Artificial intelligence in medicine.
  • Reviewer, Medical Physics.

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