collaborators

22 papers

cs.CL2026

ChatR1: Reinforcement Learning for Conversational Reasoning and Retrieval Augmented Question Answering

Simon Lupart, Mohammad Aliannejadi, Evangelos Kanoulas

We present ChatR1, a reasoning framework based on reinforcement learning (RL) for conversational question answering (CQA). Reasoning plays an important role in CQA, where user inte…

cs.AI2026

Detecting Data Contamination in Large Language Models

Juliusz Janicki, Savvas Chamezopoulos, Evangelos Kanoulas +1

Large Language Models (LLMs) utilize large amounts of data for their training, some of which may come from copyrighted sources. Membership Inference Attacks (MIA) aim to detect tho…

cs.IR2026

On the Robustness of LLM-Based Dense Retrievers: A Systematic Analysis of Generalizability and Stability

Yongkang Li, Panagiotis Eustratiadis, Yixing Fan +1

Decoder-only large language models (LLMs) are increasingly replacing BERT-style architectures as the backbone for dense retrieval, achieving substantial performance gains and broad…

cs.IR2026

Spectral Tempering for Embedding Compression in Dense Passage Retrieval

Yongkang Li, Panagiotis Eustratiadis, Evangelos Kanoulas

Dimensionality reduction is critical for deploying dense retrieval systems at scale, yet mainstream post-hoc methods face a fundamental trade-off: principal component analysis (PCA…

cs.IR2026

SubSearch: Intermediate Rewards for Unsupervised Guided Reasoning in Complex Retrieval

Roxana Petcu, Evangelos Kanoulas, Maarten de Rijke

Large language models (LLMs) are probabilistic in nature and perform more reliably when augmented with external information. As complex queries often require multi-step reasoning o…

cs.SD2026

A Novel Automatic Framework for Speaker Drift Detection in Synthesized Speech

Jia-Hong Huang, Seulgi Kim, Yi Chieh Liu +5

Recent diffusion-based text-to-speech (TTS) models achieve high naturalness and expressiveness, yet often suffer from speaker drift, a subtle, gradual shift in perceived speaker id…