Yimin Hu
Author directory2026
SkillChain: Closing the Loop on Skill Evolution for Image-Based E-Commerce AI Assistants
Yimin Hu | Mengtao Xu | Hao Guo | Yuheng Song | Xiaoyong Zhu | Bo Zheng
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Yimin Hu | Mengtao Xu | Hao Guo | Yuheng Song | Xiaoyong Zhu | Bo Zheng
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Image-based AI assistants are now deployed at production scale on e-commerce platforms, where a single uploaded image can trigger fundamentally different user intents: product search, style recommendation, visual encyclopedia, or utility tool calls, each demanding its own response format, tool invocation, and domain knowledge. Without per-intent behavioral constraints, LLM-based systems conflate these heterogeneous modes and fall short of domain quality standards, while the breadth and dynamism of the intent space render manual engineering infeasible. To address this, we present SkillChain, which closes the production feedback loop on Skill evolution, automating the lifecycle of Skills through three stages: Skill Creator for bootstrapping from task specs and trajectories, Route Optimizer for routing alignment, and Body Refiner for iterative Skill Body refinement via dual-path LLM-Judge evaluation. Deployed on a production-scale e-commerce image assistant, SkillChain substantially improves aggregate response quality, with the strongest gains on structural compliance and content quality; a one-week online A/B experiment further confirms significant gains in user engagement, content consumption, and long-term retention.
2024
Teaching Language Models to Self-Improve by Learning from Language Feedback
Chi Hu | Yimin Hu | Hang Cao | Tong Xiao | JingBo Zhu
Findings of the Association for Computational Linguistics: ACL 2024
Chi Hu | Yimin Hu | Hang Cao | Tong Xiao | JingBo Zhu
Findings of the Association for Computational Linguistics: ACL 2024
Aligning Large Language Models (LLMs) with human intentions and values is crucial yet challenging. Current methods primarily rely on human preferences, which are costly and insufficient in capturing nuanced feedback expressed in natural language. In this paper, we present Self-Refinement Tuning (SRT), a method that leverages model feedback for alignment, thereby reducing reliance on human annotations. SRT uses a base language model (e.g., Tulu2) to generate initial responses, which are critiqued and refined by a more advanced model (e.g., GPT-4-Turbo). This process enables the base model to self-evaluate and improve its outputs, facilitating continuous learning. SRT further optimizes the model by learning from its self-generated feedback and refinements, creating a feedback loop that promotes model improvement. Our empirical evaluations demonstrate that SRT significantly outperforms strong baselines across diverse tasks and model sizes. When applied to a 70B parameter model, SRT increases the win rate from 9.6% to 25.8% on the AlpacaEval 2.0 benchmark, surpassing well-established systems such as GPT-4-0314, Claude 2, and Gemini. Our analysis highlights the crucial role of language feedback in the success of SRT, suggesting potential for further exploration in this direction.
Prior Constraints-based Reward Model Training for Aligning Large Language Models
Hang Zhou | Chenglong Wang | Yimin Hu | Tong Xiao | Chunliang Zhang | Jingbo Zhu
Proceedings of the 23rd Chinese National Conference on Computational Linguistics (Volume 1: Main Conference)
Hang Zhou | Chenglong Wang | Yimin Hu | Tong Xiao | Chunliang Zhang | Jingbo Zhu
Proceedings of the 23rd Chinese National Conference on Computational Linguistics (Volume 1: Main Conference)
“Reinforcement learning with human feedback for aligning large language models (LLMs) trainsa reward model typically using ranking loss with comparison pairs. However, the training pro-cedure suffers from an inherent problem: the uncontrolled scaling of reward scores during rein-forcement learning due to the lack of constraints while training the reward model. This paperproposes a Prior Constraints-based Reward Model (PCRM) training method to mitigate thisproblem. PCRM incorporates prior constraints—specifically, length ratio and cosine similaritybetween outputs of each comparison pair—during reward model training to regulate optimiza-tion magnitude and control score margins. We comprehensively evaluate PCRM by examining itsrank correlation with human preferences and its effectiveness in aligning LLMs via RL. Exper-imental results demonstrate that PCRM significantly improves alignment performance by effec-tively constraining reward score scaling. As another bonus, our method is easily integrated intoarbitrary rank-based alignment methods, such as direct preference optimization, and can yieldconsistent improvement. The code is available at https://github.com/wangclnlp/DeepSpeed-Chat-Extension/tree/PCRM.”
2023
Sparse Frame Grouping Network with Action Centered for Untrimmed Video Paragraph Captioning
Guorui Yu | Yimin Hu | Yuejie Zhang | Rui Feng | Tao Zhang | Shang Gao
Findings of the Association for Computational Linguistics: EMNLP 2023
Guorui Yu | Yimin Hu | Yuejie Zhang | Rui Feng | Tao Zhang | Shang Gao
Findings of the Association for Computational Linguistics: EMNLP 2023
Generating paragraph captions for untrimmed videos without event annotations is challenging, especially when aiming to enhance precision and minimize repetition at the same time. To address this challenge, we propose a module called Sparse Frame Grouping (SFG). It dynamically groups event information with the help of action information for the entire video and excludes redundant frames within pre-defined clips. To enhance the performance, an Intra Contrastive Learning technique is designed to align the SFG module with the core event content in the paragraph, and an Inter Contrastive Learning technique is employed to learn action-guided context with reduced static noise simultaneously. Extensive experiments are conducted on two benchmark datasets (ActivityNet Captions and YouCook2). Results demonstrate that SFG outperforms the state-of-the-art methods on all metrics.
2022
The NiuTrans Machine Translation Systems for WMT22
Weiqiao Shan | Zhiquan Cao | Yuchen Han | Siming Wu | Yimin Hu | Jie Wang | Yi Zhang | Hou Baoyu | Hang Cao | Chenghao Gao | Xiaowen Liu | Tong Xiao | Anxiang Ma | Jingbo Zhu
Proceedings of the Seventh Conference on Machine Translation (WMT)
Weiqiao Shan | Zhiquan Cao | Yuchen Han | Siming Wu | Yimin Hu | Jie Wang | Yi Zhang | Hou Baoyu | Hang Cao | Chenghao Gao | Xiaowen Liu | Tong Xiao | Anxiang Ma | Jingbo Zhu
Proceedings of the Seventh Conference on Machine Translation (WMT)
This paper describes the NiuTrans neural machine translation systems of the WMT22 General MT constrained task. We participate in four directions, including Chinese→English, English→Croatian, and Livonian↔English. Our models are based on several advanced Transformer variants, e.g., Transformer-ODE, Universal Multiscale Transformer (UMST). The main workflow consists of data filtering, large-scale data augmentation (i.e., iterative back-translation, iterative knowledge distillation), and specific-domain fine-tuning. Moreover, we try several multi-domain methods, such as a multi-domain model structure and a multi-domain data clustering method, to rise to this year’s newly proposed multi-domain test set challenge. For low-resource scenarios, we build a multi-language translation model to enhance the performance, and try to use the pre-trained language model (mBERT) to initialize the translation model.
Improved Knowledge Distillation for Pre-trained Language Models via Knowledge Selection
Chenglong Wang | Yi Lu | Yongyu Mu | Yimin Hu | Tong Xiao | Jingbo Zhu
Findings of the Association for Computational Linguistics: EMNLP 2022
Chenglong Wang | Yi Lu | Yongyu Mu | Yimin Hu | Tong Xiao | Jingbo Zhu
Findings of the Association for Computational Linguistics: EMNLP 2022
Knowledge distillation addresses the problem of transferring knowledge from a teacher model to a student model.In this process, we typically have multiple types of knowledge extracted from the teacher model.The problem is to make full use of them to train the student model.Our preliminary study shows that: (1) not all of the knowledge is necessary for learning a good student model, and (2) knowledge distillation can benefit from certain knowledge at different training steps.In response to these, we propose an actor-critic approach to selecting appropriate knowledge to transfer during the process of knowledge distillation.In addition, we offer a refinement of the training algorithm to ease the computational burden.Experimental results on the GLUE datasets show that our method outperforms several strong knowledge distillation baselines significantly.
2021
The NiuTrans System for the WMT 2021 Efficiency Task
Chenglong Wang | Chi Hu | Yongyu Mu | Zhongxiang Yan | Siming Wu | Yimin Hu | Hang Cao | Bei Li | Ye Lin | Tong Xiao | Jingbo Zhu
Proceedings of the Sixth Conference on Machine Translation
Chenglong Wang | Chi Hu | Yongyu Mu | Zhongxiang Yan | Siming Wu | Yimin Hu | Hang Cao | Bei Li | Ye Lin | Tong Xiao | Jingbo Zhu
Proceedings of the Sixth Conference on Machine Translation
This paper describes the NiuTrans system for the WMT21 translation efficiency task. Following last year’s work, we explore various techniques to improve the efficiency while maintaining translation quality. We investigate the combinations of lightweight Transformer architectures and knowledge distillation strategies. Also, we improve the translation efficiency with graph optimization, low precision, dynamic batching, and parallel pre/post-processing. Putting these together, our system can translate 247,000 words per second on an NVIDIA A100, being 3× faster than our last year’s system. Our system is the fastest and has the lowest memory consumption on the GPU-throughput track. The code, model, and pipeline will be available at NiuTrans.NMT.
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Co-authors
- JingBo Zhu (朱靖波) 5
- Tong Xiao 4
- Hang Cao 3
- Chenglong Wang 3
- Chi Hu 2
- Yongyu Mu 2
- Siming Wu 2
- Hou Baoyu 1
- Zhiquan Cao 1
- Rui Feng 1
- Chenghao Gao 1
- Shang Gao 1
- Hao Guo 1
- Yuchen Han 1
- Bei Li 1
- Ye Lin 1
- Xiaowen Liu 1
- Yi Lu 1
- Anxiang Ma (马安香) 1
- Weiqiao Shan 1
- Yuheng Song 1
- Jie Wang 1
- Tong Xiao 1
- Mengtao Xu 1
- Zhongxiang Yan 1
- Guorui Yu 1
- Chunliang Zhang 1
- Tao Zhang 1
- Yi Zhang 1
- Yuejie Zhang 1
- Bo Zheng 1
- Hang Zhou 1
- Xiaoyong Zhu 1