Shi-Zhe Chen
Author directory2026
Beyond Sparse Rewards: A New Benchmark and Structure-Aware Graph Alignment for Micro-Drama Understanding
Yixin Qin | Shi-Zhe Chen | Zhiqi Yu | Siyuan Cheng | Tao Cheng | Jinwen Luo | Zheng Wei
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Yixin Qin | Shi-Zhe Chen | Zhiqi Yu | Siyuan Cheng | Tao Cheng | Jinwen Luo | Zheng Wei
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Micro-dramas, characterized by ultra-short durations and hyper-dense storylines, pose unique challenges for video understanding that conventional benchmarks fail to address. To bridge this gap, we introduce **M-Drama**, the first large-scale bilingual benchmark for micro-drama comprehension, featuring over 35K instances across 9,138 clips. Furthermore, while reinforcement learning can enhance VLMs on complex narratives, existing reward metrics often suffer from sparse and superficial signals, failing to capture intricate character identities and temporal structures. We propose **SAGA** (**S**tructure-**A**ware **G**raph **A**lignment), a novel graph-matching reward function that models narratives as heterogeneous graphs. SAGA computes dense, rigorous rewards via decoupled semantic triplet and structural temporal matching. Extensive experiments on Qwen3-VL-8B-Instruct demonstrate that SAGA outperforms existing baselines, delivering substantial improvements in open-ended accuracy and summary quality, while maintaining competitive out-of-domain generalization. Code is available at https://github.com/qyx1121/MDrama_SAGA.
2025
Conan-Embedding-v2: Training an LLM from Scratch for Text Embeddings
Shiyu Li | Yang Tang | Ruijie Liu | Shi-Zhe Chen | Xi Chen
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Shiyu Li | Yang Tang | Ruijie Liu | Shi-Zhe Chen | Xi Chen
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) have recently demonstrated excellent performance in text embedding tasks. Previous work usually use LoRA to fine-tune existing LLMs, which are limited by the data and training gap between LLMs and embedding models. In this work, we introduce Conan-embedding-v2, a new 1.4B-parameter LLM trained from scratch and fine-tuned as a text embedder. First, we add news data and multilingual pairs for LLM pretraining to bridge the data gap. Based on this, we propose a cross-lingual retrieval dataset that enables the LLM to better integrate embeddings across different languages. Second, whereas LLMs use a causal mask with token-level loss, embedding models use a bidirectional mask with sentence-level loss. This training gap makes full fine-tuning less effective than LoRA. We introduce a soft-masking mechanism to gradually transition between these two types of masks, enabling the model to learn more comprehensive representations. Based on this, we propose a dynamic hard negative mining method that exposes the model to more difficult negative examples throughout the training process. Being intuitive and effective, with only approximately 1.4B parameters, Conan-embedding-v2 achieves SOTA performance on both the Massive Text Embedding Benchmark (MTEB) and Chinese MTEB (May 19, 2025).