collaborators

11 papers

cs.CL2026

GUIDE: Guiding Internal Evidence with Language Instructions

Soyeon Caren Han, Hyunsuk Chung, Jinwoo Kim +2

Large multimodal models follow instructions about what to generate, but not necessarily about what evidence to rely on. Hence, models may continue to depend on shortcut-associated…

cs.CL2026

When Correct Decisions Hide Internal Stress: Decision-State Probing in Multimodal Language Models

Haoran Zhao, Soyeon Caren Han, Eduard Hovy

Multimodal language models are typically evaluated through external behavior: selecting the correct image--text match, rejecting unsupported captions, or answering visual queries c…

cs.CL2026

Inclusion-of-Thoughts: Mitigating Preference Instability via Purifying the Decision Space

Mohammad Reza Ghasemi Madani, Soyeon Caren Han, Shuo Yang +1

Multiple-choice questions (MCQs) are widely used to evaluate large language models (LLMs). However, LLMs remain vulnerable to the presence of plausible distractors. This often dive…

cs.AI2026

ToolTree: Efficient LLM Agent Tool Planning via Dual-Feedback Monte Carlo Tree Search and Bidirectional Pruning

Shuo Yang, Soyeon Caren Han, Yihao Ding +2

Large Language Model (LLM) agents are increasingly applied to complex, multi-step tasks that require interaction with diverse external tools across various domains. However, curren…

cs.CL2026

BRIDGE: Benchmark for multi-hop Reasoning In long multimodal Documents with Grounded Evidence

Biao Xiang, Soyeon Caren Han, Yihao Ding

Multi-hop question answering (QA) is widely used to evaluate the reasoning capabilities of large language models, yet most benchmarks focus on final answer correctness and overlook…

cs.AI2026

EvoTool: Self-Evolving Tool-Use Policy Optimization in LLM Agents via Blame-Aware Mutation and Diversity-Aware Selection

Shuo Yang, Soyeon Caren Han, Xueqi Ma +3

LLM-based agents depend on effective tool-use policies to solve complex tasks, yet optimizing these policies remains challenging due to delayed supervision and the difficulty of cr…

cs.CL2026

When More Is Less: A Systematic Analysis of Spatial and Commonsense Information for Visual Spatial Reasoning

Muku Akasaka, Soyeon Caren Han

Visual spatial reasoning (VSR) remains challenging for modern vision-language models (VLMs), despite advances in multimodal architectures. A common strategy is to inject additional…

cs.AI2026

Diagnosing Causal Reasoning in Vision-Language Models via Structured Relevance Graphs

Dhita Putri Pratama, Soyeon Caren Han, Yihao Ding

Large Vision-Language Models (LVLMs) achieve strong performance on visual question answering benchmarks, yet often rely on spurious correlations rather than genuine causal reasonin…

cs.AI2026

Physics-based phenomenological characterization of cross-modal bias in multimodal models

Hyeongmo Kim, Sohyun Kang, Yerin Choi +5

The term 'algorithmic fairness' is used to evaluate whether AI models operate fairly in both comparative (where fairness is understood as formal equality, such as "treat like cases…

cs.LG2026

When Is Rank-1 Enough? Geometry-Guided Initialization for Parameter-Efficient Fine-Tuning

Haoran Zhao, Soyeon Caren Han, Eduard Hovy

Parameter-efficient fine-tuning (PEFT) is a standard way to adapt multimodal large language models, yet extremely low-rank settings -- especially rank-1 LoRA -- are often unstable.…

cs.SD2026

HierCon: Hierarchical Contrastive Attention for Audio Deepfake Detection

Zhili Nicholas Liang, Soyeon Caren Han, Qizhou Wang +1

Audio deepfakes generated by modern TTS and voice conversion systems are increasingly difficult to distinguish from real speech, raising serious risks for security and online trust…