PX / INTERFACEResearch console

Hello

I develop methods for large language models, reinforcement learning, and multimodal scientific foundation models.

I am a Computer Science PhD student at the University of California, Irvine. My research spans large language models, reinforcement learning, multimodal learning, and genomic foundation models, with an emphasis on reliable evaluation and scientific applications.

I enjoy moving between methods and systems: designing objectives, building distributed training and evaluation infrastructure, and turning research questions into reproducible benchmarks. Before UCI, I earned an M.S. in Computer Engineering from UIUC and a B.S. in ECE with a Data Science minor from the University of Michigan–Shanghai Jiao Tong University Joint Institute.

LLMs + reinforcement learning Genomic AI Knowledge distillation Multimodal reasoning AI evaluation
Broader technical interests

My earlier work and continuing interests also include bioinformatics, molecular optimization, pangenome, protein and single-cell foundation models, biomedical lay summarization, tokenization and positional encodings, normalization, graph neural networks, diffusion models, computer vision, distributed machine learning, and computer architecture.

Updates

News

Recent research, releases, and milestones.

  1. Joined Pandita AI (diagram.ai)

    Working as an LLM Research Scientist Intern on verifiable evaluation and post-training for scientific diagrams.

  2. MUGO accepted to KDD 2026

    Differentiable combinatorial optimization for causal variant discovery in the non-coding genome.

  3. A Very Big Video Reasoning Suite accepted to ICML 2026

    A large-scale suite of procedurally generated tasks for long-horizon video reasoning.

  4. Team XSZ selected for an oral presentation at BioLaySumm 2025

    Section-wise retrieval, LLM generation, and reinforcement learning for biomedical lay summaries.

  5. ACM SIGBio Best Paper Award

    For work on L2 normalization and geodesic distance in high-dimensional single-cell visualization.

Current work

Research

Selected ongoing projects. Unreleased work is intentionally described at a high level.

Under review · Science Advances

OmegaGenome

Toward better sub-million-scale expert models from large genomic language models.

I lead this effort to distill genomic foundation models into deployable task experts. The work spans end-to-end training, controlled evaluation, and efficiency analysis across classification and base-resolution sequence prediction.

  • Knowledge distillation across diverse genomic teacher architectures
  • 18 classification tasks plus base-resolution multi-track regression
  • Reproducible training, benchmarking, and systems-efficiency pipelines
High-level project concept; quantitative results are omitted while under review.

DNAThinker

A reasoning-grounded multimodal foundation model for cell-type-conditioned DNA generation, editing, and pair prediction. I lead the model, data, and evaluation effort.

Research in progress

On-policy distillation for long-horizon agents

Studying stable knowledge transfer in multi-turn agent trajectories, supported by multi-GPU training and evaluation infrastructure built with FSDP, vLLM, Ray, and SLURM.

Ongoing at diagram.ai · RL post-training

DSV: verifiable rewards for scientific diagrams

Developing semantic verifiers for scientific diagrams and using their structured feedback as rewards for reinforcement-learning post-training and iterative repair.

Research in progress

Scalable, shape-aware distillation

Running controlled multi-domain studies across NLP and single-cell models, with multi-seed baselines, negative controls, and reproducible cluster-scale experiments.

Technical report · 2023

Pipe-Déjàvu

Hardware-aware, latency-predictable differentiable search for faster configuration and convergence of distributed machine-learning pipeline parallelism.

Public preprint

MIRACLE

Interpretable multi-task learning for identifying shared epigenetic regulation across autoimmune diseases, with site–gene–pathway structure built into the analysis.

Open task proposals

AgenticVBench · game understanding

I designed two proposals for long-horizon video understanding: race-telemetry reconstruction in SuperTuxKart and action-ledger reconstruction in Minecraft. Each pairs seeded generators with machine-exact ground truth, deterministic graders, and anti-shortcut calibration.

Method lab

Distillation, from objective to rollout

Inspect the manuscript-derived OmegaGenome loss anatomy and established on-policy curricula for multi-turn agents. Unreleased results are intentionally omitted.

Selected work

Publications

Peer-reviewed and accepted work, followed by selected public preprints.

MUGO framework for differentiable causal variant discovery
KDD 2026

MUGO: Differentiable Combinatorial Optimization for Causal Variant Discovery in the Non-coding Genome

Dongbo Sun, Junhao Liu, Pengcheng Xu, Yaqi Hu, Martin Jinye Zhang, Jing Zhang

Recasts causal-variant discovery as efficient differentiable search and evaluates it across multiple molecular modalities and tissues.

ICML 2026

A Very Big Video Reasoning Suite

Maijunxian Wang, …, Pengcheng Xu, Hokin Deng

A procedurally generated benchmark suite for long-horizon video reasoning. I contributed public task generators and dataset/evaluation infrastructure.

Team XSZ pipeline from article section selection and retrieval to supervised summarization and reinforcement-learning optimization
BioLaySumm 2025 · Oral

Team XSZ at BioLaySumm2025: Section-Wise Summarization, Retrieval-Augmented LLM, and Reinforcement Learning Fine-Tuning for Lay Summaries

Pengcheng Xu, Sicheng Shen, Jieli Zhou, Hongyi Xin

A section-aware pipeline combining retrieval-augmented generation and reinforcement learning for readable, faithful biomedical summaries.

Preview: Figure 1 from the paper (CC BY 4.0).

Single-cell visualization comparing distance and normalization choices
ACM BCB 2024 · SIGBio Best Paper Award

L2 Normalization and Geodesic Distance for Enhanced Information Preservation in Visualizing High-dimensional Single-cell Sequencing Data

Ziqi Rong, Jinpu Cai, Jiahao Qiu, Pengcheng Xu, Lana Garmire, Qiuyu Lian, Hongyi Xin

Studies how normalization and geodesic structure improve information preservation in high-dimensional biological visualization.

Method preview adapted from Figures 1–2; background from Figure 5.

Interactive method note Why normalization changes the geometry Trace x → z → θ → w → p → embedding; κ visibly reshapes the toy neighborhood.
Distance separation and k-nearest-neighbor accuracy on the lung-cell dataset
Distance separation and k-nearest-neighbor accuracy on the lung-cell dataset (Figure 6). The interactive diagram above is an explanatory reconstruction, not a reported experiment.
REINVENT-Transformer molecular design workflow
KDD AIDSH 2024 · Oral

REINVENT-Transformer: Molecular de-novo design through Transformer-based Reinforcement Learning

Pengcheng Xu, Tianfan Fu, Wenhao Gao, Jimeng Sun

Combines a Transformer policy with oracle-feedback reinforcement learning for goal-directed molecular generation.

Biomedical lay summarization evaluation results
ACL BioNLP 2024

Adapting Large Language Models for Biomedical Lay Summarization

Jieli Zhou*, Cheng Ye*, Pengcheng Xu, Hongyi Xin

Adapts large language models for accessible biomedical communication, with an emphasis on readability and factual quality.

Paper controls

Two published methods, made tangible

Inspect the optimization mechanics and reported ablations behind two selected papers. Illustrative quantities and published measurements are explicitly separated.

Published method MUGO · differentiable variant selection Inspect temperature and straight-through optimization.
Published method Multi-objective RL for biomedical lay summaries Inspect the public reward design and validation ablation.

Practice

Experience

Research roles, engineering systems, and teaching.

Jul 2026—Present

LLM Research Scientist Intern · Pandita AI / diagram.ai

Developing semantic verification and reinforcement-learning post-training for mathematical and scientific diagram generation.

Aug 2024—Jul 2025

Research Scientist Intern · XtalPi

Developed and benchmarked antibody binding-affinity models, with leakage-resistant data splits, balanced objectives, encoder integration, and reproducible evaluation.

May—Aug 2023

Software Engineer Intern · Amazon Web Services

Built a React/TypeScript rate-card workflow and Java/AWS backend integrations for VMware Cloud on AWS; added data-validation and anomaly-detection tooling.

May—Aug 2022

Multimodal Cognitive Computing Algorithm Intern · Shanghai AI Laboratory

Worked on multimodal target detection with zero-shot depth estimation and multimodal neural architecture search.

Jul—Oct 2022

Open-Source Software Developer · 4Paradigm / OpenMLDB

Built an automated feature-generation and selection workflow with Python and OpenMLDB SQL, then contributed it upstream and presented the system to the open-source community.

Watch the OpenMLDB Meetup talk
Nov 2021—Jun 2022

Deep Learning Software Engineer Intern · Intel Corporation

Contributed model-compression and quantization work and documentation to Intel Neural Compressor; studied inference-server architecture and helped implement C++ inference tooling.

Teaching

Teaching Assistant for UCI ICS 6B (Boolean Logic & Discrete Structures), UCI ICS 6D (Discrete Mathematics), and University of Michigan–Shanghai Jiao Tong University Joint Institute VE370 (Computer Organization).

Technical toolkit

Python, C/C++, TypeScript/JavaScript, Java, SQL, shell, CUDA, MATLAB, Verilog, and R · PyTorch, TensorFlow, Keras, scikit-learn, Pandas, Horovod, FSDP, vLLM, Ray, and SLURM · distributed training, evaluation, and benchmark design.

Selected honors

  • ACM SIGBio Best Paper Award · 2024
  • Shanghai Jiao Tong University Outstanding Graduate · 2022
  • Microsoft Imagine Cup, third prize in China · 2021
  • Mathematical Contest in Modeling, Meritorious Winner · 2020 PDF
  • CCVR “Jidong Cup,” product creative group, second prize · 2020
  • Undergraduate Excellence Scholarship · 2018–2019 and 2020–2021

Outside the paper

Interactive builds

Things I ship to learn, explain, and play.

04

Developer tool

File → Prompt

A private-by-design browser tool that builds a file tree, orders project files by folder, dependency, or name, and turns them into one structured prompt. Everything stays local.

Open the tool
05

Conversational experiment

PengchengGPT

A research-focused portfolio assistant with current UCI/CV context, offline profile commands, and a free-first model route with an explicit visitor-key fallback.

Small worlds, shipped

Four browser games on itch.io

Visit my itch.io profile

A little more human

Beyond research

Music, writing, and the story behind my name.

徐鹏程

A name about a long journey

“Pengcheng” pairs peng—the giant bird of Chinese mythology—with cheng, a journey. My parents chose it as a hope for an ambitious path and a wide horizon. In English, I pronounce my surname like “Hsu.”

Music & talks

I sing, play guitar, and record occasional technology talks. Away from a screen, I enjoy working out, basketball, tennis, table tennis, swimming, reading, science fiction, and any excuse to learn how something works. Richard Feynman and Tsung-Dao Lee are enduring inspirations.

Watch on Bilibili
Earlier guitar videos & technical talks
Video

A compact, click-to-load player; no third-party video request is made until you choose it.

Watch on Bilibili
Personal note retained from the original site

Fun fact: my MBTI result has moved between INTJ and ENTJ over time. More importantly, I try to make work that contributes something positive and outlasts the moment in which it was made.

有的时候会惧怕死亡,每个人终有一死,无一例外,如何让自己对于死亡的恐惧少一些呢?于我而言就是为社会作出尽可能多的正向贡献。 这样即使死去了,这些工作依然会留在人间,为社会上每个人的生活带来点滴的进步。就是这么一点一滴的工作才汇成了时代进步的滚滚洪流。 这些工作会代替我们留在人间。于是每能做出一些好的工作我就会对于死亡的恐惧少一点。因为我的存在或许能让世界变好那么一点点。 好像我的存在就能超脱于我的肉体而存在更久了。希望这些工作能表达我对于人类的爱,做出的这些工作就像是把对人类每一个人的爱, 写成一首情诗,嵌入在了社会大厦的一个小小砖石中。虽然路还很远自己目前做的工作根本不算什么。但我希望有一天我即使面对死亡也能 安心地说:我已经把对世界上每一个人的爱,写在了我的工作里,即使死亡也不能带走我已经有的幸福了,此生无憾矣。

Get in touch

Let’s build something rigorous—and useful.

I welcome conversations about research collaborations, reliable AI evaluation, genomics, distillation, and scientific machine learning.