Heejun Lee
Author directory2026
Multimodal Collaborative Debate for Zero-Shot Time Series Reasoning
Patara Trirat | Jin Myung Kwak | Jay Heo | Heejun Lee | Sung Ju Hwang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Patara Trirat | Jin Myung Kwak | Jay Heo | Heejun Lee | Sung Ju Hwang
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large language models (LLMs) are increasingly used as natural-language interfaces to structured data, yet they remain brittle when reasoning over time series. Visual patterns can be misleading, numerical claims can be hallucinated, and textual context can override evidence from the signal. We study *zero-shot* time-series reasoning as a multimodal evidence arbitration problem for LLM agents. We propose **TS-Debate**, an inference-time multi-agent protocol that requires no task-specific fine-tuning. TS-Debate first elicits relevant domain knowledge, then assigns modality-specialized agents to textual context, visual patterns, and numerical signals, and coordinates their interaction through a verification-conflict-calibration procedure. Reviewer agents check decision-critical claims with lightweight code execution and numerical lookup, resolve cross-modal disagreement, and calibrate the final answer. Unlike generic multi-agent debate or unconstrained tool use, TS-Debate specifies how evidence is exposed, which claims are checkable, and how verification outcomes shape synthesis. Across 20 tasks from three public benchmarks, TS-Debate improves classification and question answering performance over strong baselines, while revealing that debate is most useful for global-structure and cross-view reasoning rather than local value reconstruction.
2022
K-MHaS: A Multi-label Hate Speech Detection Dataset in Korean Online News Comment
Jean Lee | Taejun Lim | Heejun Lee | Bogeun Jo | Yangsok Kim | Heegeun Yoon | Soyeon Caren Han
Proceedings of the 29th International Conference on Computational Linguistics
Jean Lee | Taejun Lim | Heejun Lee | Bogeun Jo | Yangsok Kim | Heegeun Yoon | Soyeon Caren Han
Proceedings of the 29th International Conference on Computational Linguistics
Online hate speech detection has become an important issue due to the growth of online content, but resources in languages other than English are extremely limited. We introduce K-MHaS, a new multi-label dataset for hate speech detection that effectively handles Korean language patterns. The dataset consists of 109k utterances from news comments and provides a multi-label classification using 1 to 4 labels, and handles subjectivity and intersectionality. We evaluate strong baselines on K-MHaS. KR-BERT with a sub-character tokenizer outperforms others, recognizing decomposed characters in each hate speech class.