CV

My curriculum vitae. Click the PDF icon above to download a copy.

Contact Information

Name Xiangjun (Ethan) Fu
Professional Title Graduate Researcher, University of Pennsylvania
Email xjf@seas.upenn.edu
Phone (858) 539-5848
Location Philadelphia, PA
Website https://ethanfusion03.github.io

Professional Summary

M.S.E. student in Computer & Information Science at the University of Pennsylvania. I work on latent reasoning for large language models — continuous chain-of-thought via normalizing flows — and previously on benchmarking LLMs as semantic encoders for retrieval and recommendation.

Experience

  • 2025 - present

    Philadelphia, PA

    Graduate Researcher
    GMLR Lab, University of Pennsylvania
    Advised by Prof. Jiatao Gu.
    • Designing a continuous latent chain-of-thought reasoning pipeline on a Qwen3-8B backbone that operates in a lower-dimensional space while preserving semantic structure.
    • Fine-tuning an LLM-based VAE encoder to provide semantic guidance for latent thinking-token generation; using normalizing flows to autoregressively generate thinking tokens under an MSE objective against VAE-encoded latents.
    • Computing step-wise log-likelihoods to enable reinforcement learning over reasoning trajectories, with evaluation protocols for trajectory selection.
  • 2024 - 2025

    San Diego, CA

    Undergraduate Researcher
    McAuley Lab, UC San Diego
    Advised by Prof. Julian McAuley and Yupeng Hou.
    • Built an evaluation framework for benchmarking LLM text embeddings in retrieval and recommendation, including a public Amazon dataset with 2M+ training and 250K+ test instances.
    • Benchmarked embeddings from SimCSE, E5-Mistral-7B, text-embedding-3-large, Qwen-7B, Gemini, and OpenAI across collaborative filtering, sequential recommendation, and product search; co-first-authored the resulting ACL 2026 paper.
  • 2023 - 2024

    San Diego, CA

    Undergraduate Researcher
    Shang Data Lab, UC San Diego
    Advised by Prof. Jingbo Shang and Letian Peng.
    • Refined weakly supervised text classification, reaching 93% peak accuracy on AG News (vs. 78% baseline) via KL-divergence matching between token-level text and class-prompt distributions.
    • Implemented the framework in PyTorch with BERT, RoBERTa, and Gemma across AG News and Rotten Tomatoes.

Education

  • 2025 - 2027

    Philadelphia, PA

    M.S.E. in Computer & Information Science
    University of Pennsylvania
    • GPA: 3.95 / 4.0
    • Relevant coursework: Statistical NLP, Deep Learning, Deep Generative Modeling, Reinforcement Learning, Machine Learning, Recommender Systems & Web Mining, Probability & Statistics
  • 2021 - 2025

    San Diego, CA

    B.S. in Mathematics–Computer Science
    University of California, San Diego
    • GPA: 3.9 / 4.0 · Provost Honors

Publications

Teaching

  • Supplemental Instruction Leader, Academic Achievement Hub, UC San Diego (2024–2025). Led weekly workshops for 50+ students in Physics and Calculus (~20 hrs/week), translating complex technical material into accessible, interactive lessons; iterated lesson design from student and faculty feedback and provided one-on-one mentorship.

Academic Service

  • Reviewer: EMNLP 2026 (ACL Rolling Review, May cycle), NeurIPS 2026.

Skills

Programming: Python, C/C++, Java, SQL, Bash
ML & NLP: PyTorch, Hugging Face Transformers, LLM fine-tuning (LoRA, full fine-tuning), normalizing flows, flow matching/diffusion, VAEs, embedding models (BERT, RoBERTa, Mistral, Qwen), OpenAI / Gemini / Claude APIs
Tools: NumPy, Pandas, Matplotlib, Jupyter, Git, Linux, Vim, gdb, SLURM / HPC clusters, conda

Languages

English : Fluent
Mandarin : Fluent
Cantonese : Conversational
Spanish : Conversational