collaborators

11 papers

cs.CL2026

Equitable System-Prompt Selection via Constrained Mixed-Strategy GroupDRO

Mengyu Xu, Qiaoxin Yang, Zhihan Liu +4

Large language models are increasingly used for information seeking, yet semantically equivalent questions phrased in different ways can receive answers of considerably different q…

cs.CL2026

The Text Uncanny Valley: Non-Monotonic Performance Degradation in LLM Information Retrieval

Zekai Tong, Ruiyao Xu, Aryan Shrivastava +2

Existing Large Language Model (LLM) benchmarks primarily focus on syntactically correct inputs, leaving a significant gap in evaluation on imperfect text. In this work, we study ho…

cs.CL2026

Geometry-Calibrated Conformal Abstention for Language Models

Rui Xu, Yi Chen, Sihong Xie +1

When language models lack relevant knowledge for a given query, they frequently generate plausible responses that can be hallucinations, rather than admitting being agnostic about…

cs.CL2026

Cat-DPO: Category-Adaptive Safety Alignment

Tiankai Yang, Yi Nian, Xinyuan Li +6

Aligning large language models with human preferences must balance two competing goals: responding helpfully to legitimate requests and reliably refusing harmful ones. Most prefere…

cs.CL2026

CoAct: Co-Active LLM Preference Learning with Human-AI Synergy

Ruiyao Xu, Mihir Parmar, Tiankai Yang +3

Learning from preference-based feedback has become an effective approach for aligning LLMs across diverse tasks. However, high-quality human-annotated preference data remains expen…

cs.CL2026

No Attacker Needed: Unintentional Cross-User Contamination in Shared-State LLM Agents

Tiankai Yang, Jiate Li, Yi Nian +5

LLM-based agents increasingly operate across repeated sessions, maintaining task states to ensure continuity. In many deployments, a single agent serves multiple users within a tea…