Sitemap
A list of all the posts and pages found on the site. For you robots out there, there is an XML version available for digesting as well.
Pages
Posts
portfolio
Flappy-Bird-AI
An RL agent trained with Proximal Policy Optimization (PPO) to play Flappy Bird — a sandbox for reward shaping, observation design, and stable policy-gradient training under sparse, repetitive feedback.
gradescope-mcp
An open-source MCP server with 34 tools that lets AI assistants drive Gradescope workflows — course, assignment, rubric, submission, roster, extension, and regrade management — under a human-approved ‘preview-first’ write protocol.
StudyGround
A Claude Code plugin for AI-assisted self-study: rendered lessons in a local web reader, in-browser Python via Pyodide, a course-aware tutor, and one-click hand-off into VSCode for exercises.
publications
TOPPO: Rethinking PPO for Multi-Task Reinforcement Learning with Critic Balancing
Under review
Multi-task PPO suffers from critic-side gradient ill-conditioning where tail tasks stall while easy tasks dominate value-function updates. We introduce Critic Balancing — per-task PopArt value normalization, pre-activation LayerNorm in the critic body, and per-side gradient combiners (PCGrad / CAGrad / FairGrad chosen independently for actor and critic). On Meta-World+ MT50 it surpasses published SAC- and ARS-family baselines on both mean and worst-k tail-task success while using up to 22.7× fewer parameters and substantially fewer environment steps.
Yuanpeng Li, Gefei Lin, Annie Qu, Rui Miao. Under review. arXiv:2605.11473
talks
teaching
STATS 110 — Statistical Methods for Data Analysis I
Undergraduate course, UC Irvine, Department of Statistics, 2024
Graduate teaching assistant. ANOVA, simple and multiple linear regression.
STATS 120C — Introduction to Probability and Statistics III
Undergraduate course, UC Irvine, Department of Statistics, 2024
Graduate teaching assistant. Likelihood-ratio tests, ANOVA, regression inference and diagnostics.
STATS 205P — Bayesian Data Analysis
Graduate course, UC Irvine, Master of Data Science Program, 2024
Graduate teaching assistant. Prior specification, Bayesian linear and generalized linear regression for the Master of Data Science program.
STATS 67 — Introduction to Probability and Statistics for Computer Science
Undergraduate course, UC Irvine, Department of Statistics, 2024
Graduate teaching assistant. Probability and statistics for computer science majors.
STATS 7 — Basic Statistics
Undergraduate course, UC Irvine, Department of Statistics, 2024
Graduate teaching assistant. Introductory inferential statistics: confidence intervals, hypothesis testing, and regression.