Large Language Model
AILS-NTUA at SemEval-2025 Task 4: Parameter-Efficient Unlearning for Large Language Models using Data Chunking
Premptis, Iraklis, Lymperaiou, Maria, Filandrianos, Giorgos, Mastromichalakis, Orfeas Menis, Voulodimos, Athanasios, Stamou, Giorgos
The Unlearning Sensitive Content from Large Language Models task aims to remove targeted datapoints from trained models while minimally affecting their general knowledge. In our work, we leverage parameter-efficient, gradient-based unlearning using low-rank (LoRA) adaptation and layer-focused fine-tuning. To further enhance unlearning effectiveness, we employ data chunking, splitting forget data into disjoint partitions and merging them with cyclically sampled retain samples at a pre-defined ratio. Our task-agnostic method achieves an outstanding forget-retain balance, ranking first on leaderboards and significantly outperforming baselines and competing systems.
AILS-NTUA at SemEval-2025 Task 3: Leveraging Large Language Models and Translation Strategies for Multilingual Hallucination Detection
Karkani, Dimitra, Lymperaiou, Maria, Filandrianos, Giorgos, Spanos, Nikolaos, Voulodimos, Athanasios, Stamou, Giorgos
Multilingual hallucination detection stands as an underexplored challenge, which the Mu-SHROOM shared task seeks to address. In this work, we propose an efficient, training-free LLM prompting strategy that enhances detection by translating multilingual text spans into English. Our approach achieves competitive rankings across multiple languages, securing two first positions in low-resource languages. The consistency of our results highlights the effectiveness of our translation strategy for hallucination detection, demonstrating its applicability regardless of the source language.
A Transformer-Based Framework for Greek Sign Language Production using Extended Skeletal Motion Representations
Pratikaki, Chrysa, Filntisis, Panagiotis, Katsamanis, Athanasios, Roussos, Anastasios, Maragos, Petros
Building on To address communication barriers between the DHH (Deaf and insights from previous research, we propose a deep learning model Hard-of-Hearing) and the hearing communities, the field of Sign for Sign Language Production (SLP), which to our knowledge is Language Processing has emerged at the intersection of linguistics, the first attempt on Greek SLP. We tackle this task by utilizing a computer vision, and machine learning. Sign Language Processing transformer-based architecture that enables the translation from encompasses a variety of tasks aimed at bridging the gap between text input to human pose keypoints, and the opposite. We evaluate DHH and hearing communities by enabling the automatic translation, the effectiveness of the proposed pipeline on the Greek SL dataset and generation of sign language. The most critical components Elementary23, through a series of comparative analyses and ablation of an effective sign language system are Sign Language Translation studies. Our pipeline's components, which include data-driven (SLT), and Sign Language Production (SLP). In this paper, we gloss generation, training through video to text translation and a primarily focus on Sign Language Production (SLP).
Hierarchical Re-ranker Retriever (HRR)
Singh, Ashish, Mohapatra, Priti
Retrieving the right level of context for a given query is a perennial challenge in information retrieval--too large a chunk dilutes semantic specificity, while chunks that are too small lack broader context. This paper introduces the Hierarchical Re-ranker Retriever (HRR), a framework designed to achieve both fine-grained and high-level context retrieval for large language model (LLM) applications. In HRR, documents are split into sentence-level and intermediate-level (512 tokens) chunks to maximize vector-search quality for both short and broad queries. We then employ a reranker that operates on these 512-token chunks, ensuring an optimal balance--neither too coarse nor too fine--for robust relevance scoring. Finally, top-ranked intermediate chunks are mapped to parent chunks (2048 tokens) to provide an LLM with sufficiently large context. We compare HRR against three widely used alternatives(details of them can be found in appendix section): 1. Base Retriever + Reranker 2. ChildToParent(C2P) Retriever + Reranker 3. SentenceToParent(S2P) Retriever + Reranker Experiments on two datasets--Yojana and Lendryl--demonstrate that HRR consistently outperforms these baselines in both Hit Rate (HR) and Mean Reciprocal Rank (MRR). On Yojana, HRR achieves a perfect 100% Hit Rate and an MRR of 96.15% which is 25% higher than Base Retriever and around 15% higher than C2P or S2P retriever. Similarly, on Lendryl, HRR attains MRR which is 20% and 10% higher than Base Retriever and C2P or S2P retriever respectively. These results confirm that a multi-stage retrieval strategy--fine-grained sentence-level and intermediate level(512 token) filtering, optimized 512 token reranking, and final parent-chunk(2048 token) mapping--delivers more accurate, context-rich retrieval well-suited for downstream LLM tasks.
VisAgent: Narrative-Preserving Story Visualization Framework
Kim, Seungkwon, Park, GyuTae, Kim, Sangyeon, Nam, Seung-Hun
Story visualization is the transformation of narrative elements into image sequences. While existing research has primarily focused on visual contextual coherence, the deeper narrative essence of stories often remains overlooked. This limitation hinders the practical application of these approaches, as generated images frequently fail to capture the intended meaning and nuances of the narrative fully. To address these challenges, we propose VisAgent, a training-free multi-agent framework designed to comprehend and visualize pivotal scenes within a given story. By considering story distillation, semantic consistency, and contextual coherence, VisAgent employs an agentic workflow. In this workflow, multiple specialized agents collaborate to: (i) refine layered prompts based on the narrative structure and (ii) seamlessly integrate \gt{generated} elements, including refined prompts, scene elements, and subject placement, into the final image. The empirically validated effectiveness confirms the framework's suitability for practical story visualization applications.
PersonaX: A Recommendation Agent Oriented User Modeling Framework for Long Behavior Sequence
Shi, Yunxiao, Xu, Wujiang, Zhang, Zeqi, Zi, Xing, Wu, Qiang, Xu, Min
Recommendation agents leverage large language models for user modeling LLM UM to construct textual personas guiding alignment with real users. However existing LLM UM methods struggle with long user generated content UGC due to context limitations and performance degradation. To address this sampling strategies prioritize relevance or recency are often applied yet they inevitably neglect the diverse user interests embedded within the discarded behaviors resulting in incomplete modeling and degraded profiling quality. Furthermore relevance based sampling requires real time retrieval forcing the user modeling process to operate online which introduces significant latency overhead. In this paper we propose PersonaX an agent agnostic LLM UM framework that tackles these challenges through sub behavior sequence SBS selection and offline multi persona construction. PersonaX extracts compact SBS segments offline to capture diverse user interests generating fine grained textual personas that are cached for efficient online retrieval. This approach ensures that the user persona used for prompting remains highly relevant to the current context while eliminating the need for online user modeling. For SBS selection we ensure both efficiency length less than five and high representational quality by balancing prototypicality and diversity within the sampled data. Extensive experiments validate the effectiveness and versatility of PersonaX in high quality user profiling. Utilizing only 30 to 50 percent of the behavioral data with a sequence length of 480 integrating PersonaX with AgentCF yields an absolute performance improvement of 3 to 11 percent while integration with Agent4Rec results in a gain of 10 to 50 percent. PersonaX as an agent agnostic framework sets a new benchmark for scalable user modeling paving the way for more accurate and efficient LLM driven recommendation agents.
An Efficient and Precise Training Data Construction Framework for Process-supervised Reward Model in Mathematical Reasoning
Sun, Wei, Du, Qianlong, Cui, Fuwei, Zhang, Jiajun
Enhancing the mathematical reasoning capabilities of Large Language Models (LLMs) is of great scientific and practical significance. Researchers typically employ process-supervised reward models (PRMs) to guide the reasoning process, effectively improving the models' reasoning abilities. However, existing methods for constructing process supervision training data, such as manual annotation and per-step Monte Carlo estimation, are often costly or suffer from poor quality. To address these challenges, this paper introduces a framework called EpicPRM, which annotates each intermediate reasoning step based on its quantified contribution and uses an adaptive binary search algorithm to enhance both annotation precision and efficiency. Using this approach, we efficiently construct a high-quality process supervision training dataset named Epic50k, consisting of 50k annotated intermediate steps. Compared to other publicly available datasets, the PRM trained on Epic50k demonstrates significantly superior performance. Getting Epic50k at https://github.com/xiaolizh1/EpicPRM.
Teaching Metric Distance to Autoregressive Multimodal Foundational Models
Chung, Jiwan, Kim, Saejin, Jo, Yongrae, Park, Jaewoo, Min, Dongjun, Yu, Youngjae
As large language models expand beyond natural language to domains such as mathematics, multimodal understanding, and embodied agents, tokens increasingly reflect metric relationships rather than purely linguistic meaning. We introduce DIST2Loss, a distance-aware framework designed to train autoregressive discrete models by leveraging predefined distance relationships among output tokens. At its core, DIST2Loss transforms continuous exponential family distributions derived from inherent distance metrics into discrete, categorical optimization targets compatible with the models' architectures. This approach enables the models to learn and preserve meaningful distance relationships during token generation while maintaining compatibility with existing architectures. Empirical evaluations show consistent performance gains in diverse multimodal applications, including visual grounding, robotic manipulation, generative reward modeling, and image generation using vector-quantized features. These improvements are pronounced in cases of limited training data, highlighting DIST2Loss's effectiveness in resource-constrained settings.
MedEthicEval: Evaluating Large Language Models Based on Chinese Medical Ethics
Jin, Haoan, Shi, Jiacheng, Xu, Hanhui, Zhu, Kenny Q., Wu, Mengyue
Large language models (LLMs) demonstrate significant potential in advancing medical applications, yet their capabilities in addressing medical ethics challenges remain underexplored. This paper introduces MedEthicEval, a novel benchmark designed to systematically evaluate LLMs in the domain of medical ethics. Our framework encompasses two key components: knowledge, assessing the models' grasp of medical ethics principles, and application, focusing on their ability to apply these principles across diverse scenarios. To support this benchmark, we consulted with medical ethics researchers and developed three datasets addressing distinct ethical challenges: blatant violations of medical ethics, priority dilemmas with clear inclinations, and equilibrium dilemmas without obvious resolutions. MedEthicEval serves as a critical tool for understanding LLMs' ethical reasoning in healthcare, paving the way for their responsible and effective use in medical contexts.
Add-One-In: Incremental Sample Selection for Large Language Models via a Choice-Based Greedy Paradigm
Li, Zhuo, Du, Yuhao, Jiao, Xiaoqi, Guo, Yiwen, Feng, Yuege, Wan, Xiang, Gao, Anningzhe, Hu, Jinpeng
Selecting high-quality and diverse training samples from extensive datasets plays a crucial role in reducing training overhead and enhancing the performance of Large Language Models (LLMs). However, existing studies fall short in assessing the overall value of selected data, focusing primarily on individual quality, and struggle to strike an effective balance between ensuring diversity and minimizing data point traversals. Therefore, this paper introduces a novel choice-based sample selection framework that shifts the focus from evaluating individual sample quality to comparing the contribution value of different samples when incorporated into the subset. Thanks to the advanced language understanding capabilities of LLMs, we utilize LLMs to evaluate the value of each option during the selection process. Furthermore, we design a greedy sampling process where samples are incrementally added to the subset, thereby improving efficiency by eliminating the need for exhaustive traversal of the entire dataset with the limited budget. Extensive experiments demonstrate that selected data from our method not only surpass the performance of the full dataset but also achieves competitive results with state-of-the-art (SOTA) studies, while requiring fewer selections. Moreover, we validate our approach on a larger medical dataset, highlighting its practical applicability in real-world applications.