Subeen Park


2025

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TIDES: Technical Information Discovery and Extraction System
Jihee Kim | Subeen Park | Hakyung Lee | YongTaek Lim | Hyo-won Suh | Kyungwoo Song
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing

Addressing the challenges in QA for specific technical domains requires identifying relevant portions of extensive documents and generating answers based on this focused content. Traditional pre-trained LLMs often struggle with domain-specific terminology, while fine-tuned LLMs demand substantial computational resources. To overcome these limitations, we propose TIDES, Technical Information Distillation and Extraction System. TIDES is a training-free approach that combines traditional TF-IDF techniques with prompt-based LLMs in a hybrid process, effectively addressing complex technical questions. It uses TF-IDF to identify and prioritize domain-specific words that are rare in other documents and LLMs to refine the candidate pool by focusing on the most relevant segments in documents through multiple stages. Our approach improves the precision and efficiency of QA systems in technical contexts without LLM retraining.

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Uncertainty-Aware Contrastive Decoding
Hakyung Lee | Subeen Park | Joowang Kim | Sungjun Lim | Kyungwoo Song
Findings of the Association for Computational Linguistics: ACL 2025

Large language models excel in a wide range of natural language processing tasks, but generating factually accurate and consistent outputs remains a challenge. To improve text reliability, Contrastive Decoding (CD) refines token selection by leveraging differences between an expert and base model, penalizing low-quality token choices. However, CD employs static weighting between models, making it sensitive to variations in model architecture and input characteristics, often resulting in suboptimal token selection and error propagation throughout generation. We propose Uncertainty-Aware Contrastive Decoding (UCD), a method that dynamically adjusts model contributions at each decoding step based on uncertainty. We introduce a cumulative energy function, where uncertainty is quantified as the negative log-sum-exp over logits, and decomposed into entropy and expected logit components. This energy serves as a dynamic confidence signal, guiding adaptive model weighting during generation. We demonstrate through extensive experiments that UCD significantly improves factual accuracy and reliability over existing decoding methods. Finally, we provide a theoretical analysis showing that our energy function serves as a well-defined uncertainty metric capturing model confidence. Our code is available at: https://github.com/MLAI-Yonsei/UCD.