Chae Won Kim
Author directory2026
Diffusion Large Language Models for Visual Speech Recognition
Jeong Hun Yeo | Chae Won Kim | Hyeongseop Rha | Yong Man Ro
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Jeong Hun Yeo | Chae Won Kim | Hyeongseop Rha | Yong Man Ro
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Existing Visual Speech Recognition (VSR) systems commonly rely on left-to-right autoregressive decoding, which can force premature decisions on visually ambiguous tokens before sufficient context is available. We propose DLLM-VSR, to the best of our knowledge, the first Diffusion Large Language Model (DLLM)-based VSR framework, formulating transcription as iterative masked denoising with flexible-order decoding. With confidence-based unmasking, DLLM-VSR commits high-confidence positions early and uses the committed tokens as bidirectional context to refine ambiguous ones. To adapt DLLMs to VSR, we introduce a two-stage masked-denoising training strategy that separates visual-to-text content alignment from length modeling. We further observe a performance gap compared with an upper-bound setting where the ground-truth transcript length is provided at inference, allowing the model to focus on transcript content decoding. To reduce this gap, we develop length-guided candidate decoding, which uses video duration to construct plausible transcript-length hypotheses and reranks the decoded candidates using length plausibility and decoding confidence. The proposed method achieves a 19.4% word error rate on LRS3, establishing state-of-the-art performance among methods using only LRS3 as labeled training data.
2024
CoLLaVO: Crayon Large Language and Vision mOdel
Byung-Kwan Lee | Beomchan Park | Chae Won Kim | Yong Man Ro
Findings of the Association for Computational Linguistics: ACL 2024
Byung-Kwan Lee | Beomchan Park | Chae Won Kim | Yong Man Ro
Findings of the Association for Computational Linguistics: ACL 2024
The remarkable success of Large Language Models (LLMs) and instruction tuning drives the evolution of Vision Language Models (VLMs) towards a versatile general-purpose model. Yet, it remains unexplored whether current VLMs genuinely possess quality object-level image understanding capabilities determined from ‘what objects are in the image?’ or ‘which object corresponds to a specified bounding box?’. Our findings reveal that the image understanding capabilities of current VLMs are strongly correlated with their zero-shot performance on vision language (VL) tasks. This suggests that prioritizing basic image understanding is crucial for VLMs to excel at VL tasks. To enhance object-level image understanding, we propose Crayon Large Language and Vision mOdel (CoLLaVO), which incorporates instruction tuning with Crayon Prompt as a new visual prompt tuning scheme based on panoptic color maps. Furthermore, we present a learning strategy of Dual QLoRA to preserve object-level image understanding without forgetting it during visual instruction tuning, thereby achieving a significant leap in numerous VL benchmarks in a zero-shot setting.
TroL: Traversal of Layers for Large Language and Vision Models
Byung-Kwan Lee | Sangyun Chung | Chae Won Kim | Beomchan Park | Yong Man Ro
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Byung-Kwan Lee | Sangyun Chung | Chae Won Kim | Beomchan Park | Yong Man Ro
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Large language and vision models (LLVMs) have been driven by the generalization power of large language models (LLMs) and the advent of visual instruction tuning. Along with scaling them up directly, these models enable LLVMs to showcase powerful vision language (VL) performances by covering diverse tasks via natural language instructions. However, existing open-source LLVMs that perform comparably to closed-source LLVMs such as GPT-4V are often considered too large (e.g., 26B, 34B, and 110B parameters), having a larger number of layers. These large models demand costly, high-end resources for both training and inference. To address this issue, we present a new efficient LLVM family with 1.8B, 3.8B, and 7B LLM model sizes, Traversal of Layers (TroL), which enables the reuse of layers in a token-wise manner. This layer traversing technique simulates the effect of looking back and retracing the answering stream while increasing the number of forward propagation layers without physically adding more layers. We demonstrate that TroL employs a simple layer traversing approach yet efficiently outperforms the open-source LLVMs with larger model sizes and rivals the performances of the closed-source LLVMs with substantial sizes.