Junehyoung Kwon
Author directory2026
Align, Don’t Fuse: Structure-Preserving Alignment of Collaborative and Semantic Signals for LLM-Enhanced Recommendation
Jooweon Choi | MiHyeon Kim | Eunju Lee | Junehyoung Kwon | YoungBin Kim
Findings of the Association for Computational Linguistics: EMNLP 2026
Jooweon Choi | MiHyeon Kim | Eunju Lee | Junehyoung Kwon | YoungBin Kim
Findings of the Association for Computational Linguistics: EMNLP 2026
Large Language Models (LLMs) provide rich semantic representations for recommender systems, but their semantic similarity may not align with collaborative preference patterns captured by collaborative filtering (CF). Directly combining LLM and CF representations can therefore distort the structural relationships encoded in the interaction graph. We propose Structure-Preserving Alignment (SPA), which reformulates CF–LLM integration as language-supervised representation alignment. SPA derives collaborative anchors from frozen CF representations and aligns multiple LLM-generated semantic views toward these anchors through cross-profile view competition. The aligned collaborative representations are then used for structure-preserving two-channel retrieval, which constructs behavior-aware context for downstream LLM-based preference prediction. Experiments on multiple datasets and CF backbones show that SPA consistently improves click-through rate (CTR)-style binary preference prediction.
Aligning with Your Own Voice: Self-Corrected Preference Learning for Hallucination Mitigation in LVLMs
Byeonggeuk Lim | JungMin Yun | Junehyoung Kwon | Kyeonghyun Kim | YoungBin Kim
Findings of the Association for Computational Linguistics: ACL 2026
Byeonggeuk Lim | JungMin Yun | Junehyoung Kwon | Kyeonghyun Kim | YoungBin Kim
Findings of the Association for Computational Linguistics: ACL 2026
Large Vision-Language Models (LVLMs) frequently suffer from hallucinations. Existing preference learning-based approaches largely rely on proprietary models to construct preference datasets. We identify that this reliance introduces a distributional mismatch between the proprietary and target models that hinders efficient alignment. To address this, we propose Alignment via VErified Self-correction DPO (AVES-DPO), a framework that aligns LVLMs using in-distribution data derived from the model’s intrinsic knowledge. Our approach employs a consensus-based verification mechanism to diagnose diverse hallucinations and guides the model to self-correct, thereby generating preference pairs strictly compatible with its internal distribution. Extensive experiments demonstrate that AVES-DPO surpasses existing baselines in hallucination mitigation while requiring only 5.2k samples.
Before Forgetting, Learn to Remember: Revisiting Foundational Learning Failures in LVLM Unlearning Benchmarks
Junehyoung Kwon | MiHyeon Kim | Eunju Lee | JungMin Yun | Byeonggeuk Lim | YoungBin Kim
Findings of the Association for Computational Linguistics: ACL 2026
Junehyoung Kwon | MiHyeon Kim | Eunju Lee | JungMin Yun | Byeonggeuk Lim | YoungBin Kim
Findings of the Association for Computational Linguistics: ACL 2026
While Large Vision-Language Models (LVLMs) offer powerful capabilities, they pose privacy risks by unintentionally memorizing sensitive personal information. Current unlearning benchmarks attempt to mitigate this using fictitious identities but overlook a critical stage 1 failure: models fail to effectively memorize target information initially, rendering subsequent unlearning evaluations unreliable. Diagnosing under-memorization and the multi-hop curse as root causes, we introduce ReMem, a Reliable Multi-hop and Multi-image Memorization Benchmark. ReMem ensures robust foundational learning through principled data scaling, reasoning-aware QA pairs, and diverse visual contexts. Additionally, we propose a novel Exposure metric to quantify the depth of information erasure from the model’s internal probability distribution. Extensive experiments demonstrate that ReMem provides a rigorous and trustworthy framework for diagnosing both learning and unlearning behaviors in LVLMs.
Beyond Safe Answers: Segment-Aware Listwise Alignment for Reasoning Safety in Large Reasoning Models
JungMin Yun | Junehyoung Kwon | Hayeong Ryu | Byeonggeuk Lim | Hoejoon Kwon | YoungBin Kim
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
JungMin Yun | Junehyoung Kwon | Hayeong Ryu | Byeonggeuk Lim | Hoejoon Kwon | YoungBin Kim
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large Reasoning Models (LRMs) pose a dual-surface safety challenge: both intermediate reasoning traces and final answers can contain harmful content. Existing alignment methods often operate at the whole-response level, allowing unsafe reasoning to be masked by a safe-looking final answer. We propose Segment-aware Listwise Target DPO (SaLT-DPO), which addresses this gap through three mechanisms: (1) segment-aware listwise alignment that decomposes responses into reasoning and answer segments, independently scores each segment’s safety, and aligns length-normalized segment rewards with soft target distributions over multiple candidates; (2) joint safety coherence regularization that applies a weakest-link principle to promote safety consistency across both segments; and (3) utility anchoring on benign prompts to mitigate over-refusal and reasoning degradation. Experiments on three LRMs show that SaLT-DPO consistently reduces unsafe rates for both reasoning and answer segments while mitigating degradation in benign compliance and preserving general reasoning performance. Ablation studies demonstrate the complementary contributions of its components.
2025
See-Saw Modality Balance: See Gradient, and Sew Impaired Vision-Language Balance to Mitigate Dominant Modality Bias
Junehyoung Kwon | MiHyeon Kim | Eunju Lee | Juhwan Choi | YoungBin Kim
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Junehyoung Kwon | MiHyeon Kim | Eunju Lee | Juhwan Choi | YoungBin Kim
Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers)
Vision-language (VL) models have demonstrated strong performance across various tasks. However, these models often rely on a specific modality for predictions, leading to “dominant modality bias.” This bias significantly hurts performance, especially when one modality is impaired. In this study, we analyze model behavior under dominant modality bias and theoretically show that unaligned gradients or differences in gradient magnitudes prevent balanced convergence of the loss. Based on these findings, we propose a novel framework, BalGrad to mitigate dominant modality bias. Our approach includes inter-modality gradient reweighting, adjusting the gradient of KL divergence based on each modality’s contribution, and inter-task gradient projection to align task directions in a non-conflicting manner. Experiments on UPMC Food-101, Hateful Memes, and MM-IMDb datasets confirm that BalGrad effectively alleviates over-reliance on specific modalities when making predictions.