Qifei Cui

Qifei Cui

he/him/his

My research seeks intelligence that flows naturally through constraints — whether teaching machines to move with human grace or to reason with mathematical clarity.

Blog posts

2025

GRPO-RS: A Next-Gen Graph-based Reinforcement Learning Framework for Recommender Systems

5 minute read

Published:

Recommender systems (RS) have seen rapid evolution in recent years, especially with the rise of Graph Neural Networks (GNNs) and Reinforcement Learning (RL). However, most existing solutions still struggle with challenges such as data sparsity, cold start, and the long-tail effect. We introduce GRPO-RS—a novel architecture combining graph signal regularization and reinforcement learning for offline and scalable recommendation optimization.

Bridging HPSTM and SKEL

1 minute read

Published:

Feeding 46 biomechanical angles into the kinematic layer is the moment HPSTM truly shakes hands with SKEL.

Camera Pose Expressions for HPSTM-Skeleton-NeRF Integration

2 minute read

Published:

Skeleton serves as an explicit warp between canonical space and every posed frame. The render-and-compare loss feeds back dense gradients that refine both the NeRF and the HPSTM joint angles simultaneously.

From HPSTM to HPSTM-Gen

2 minute read

Published:

Why we’re turning our pose-smoothing Transformer into a generative motion model for VLA research

Tired of Coding? Try This Effortless Korean Short Rib Bake!

2 minute read

Published:

After a long day wrestling with code and debugging errors, sometimes the best therapy is a break away from the screen—preferably, into the kitchen. If you’re looking for something rewarding but not too complicated, this Korean-style baked short rib stew is the perfect dish to revive both your mood and your energy.

Pride 2025: Be an Ally by Raising Up a Flag

1 minute read

Published:

Happy Pride Month! June is a time for celebration, reflection, and showing support for the LGBTQ+ community. As developers, we have a unique canvas for expression: our own websites. Adding a small touch of Pride to a personal site is a wonderful way to signal that it’s a safe, inclusive space and to stand as an ally.