activity
20162026
most citedNowcasting the Stance of Social Media Users in a Sudden Vote: The Case of the Greek Referendum

26 citations · 136 across the 69 of their papers we have counts for

collaborators

82 papers

cs.CL2026

Upcycling Language Models for Multiple Specialized Domains

Mingzi Cao, Xi Wang, Nikolaos Aletras

Effective multi-domain adaptation of large language models requires prioritizing relevant domain knowledge while minimizing interference from irrelevant domains. Existing approache…

cs.CL2026

Evaluating and Improving Evidence-Grounded Fact-Checking in LLMs via Multi-Round Evidence Ablation

Xingyu Deng, Mingzi Cao, Nikolaos Aletras +2

Automatic fact-checking systems assess the veracity of claims given evidence from relevant documents. Large Language Models (LLMs) have demonstrated strong performance in fact-chec…

cs.CL2026

When Tokenizers Fail: Byte-Level Chunking for Zero-Shot Transfer to Low-Resource Languages

Sanjeev Kumar, Atsuki Yamaguchi, Nikolaos Aletras

Subword tokenization hinders low-resource language processing by imposing frequency patterns from dominant languages onto script-sharing variants. Byte-level models bypass this iss…

cs.LG2026

On the Utility and Factual Reliability of Pruned Mixture-of-Experts Models in the Biomedical Domain

Atsuki Yamaguchi, Szymon Palucha, Léo Bijar +2

Mixture-of-Experts (MoE) models offer inference speedups via selective activation but impose substantial memory requirements because the whole network must remain loaded. Structure…

cs.CL2026

MultiHashFormer: Hash-based Generative Language Models

Huiyin Xue, Atsuki Yamaguchi, Nikolaos Aletras

Language models (LMs) represent tokens using embedding matrices that scale linearly with the vocabulary size. To constrain the parameter footprint, prior work proposes hashing many…

cs.LG2026

Boundary-targeted Membership Inference Attacks on Safety Classifiers

Anthony Hughes, Alexander Goldberg, Prince Jha +3

Safety classifiers are essential safeguards within generative AI systems, filtering harmful content or identifying at-risk users when interacting with large language models. Despit…

cs.CL2026

Where does output diversity collapse in post-training?

Constantinos Karouzos, Xingwei Tan, Nikolaos Aletras

Post-trained language models produce less varied outputs than their base counterparts. This output diversity collapse undermines inference-time scaling methods that rely on varied…

cs.CL2026

Enhancing Linguistic Competence of Language Models through Pre-training with Language Learning Tasks

Atsuki Yamaguchi, Maggie Mi, Nikolaos Aletras

Language models (LMs) are pre-trained on raw text datasets to generate text sequences token-by-token. While this approach facilitates the learning of world knowledge and reasoning,…

cs.CL2025★ 1 cited

Mitigating Catastrophic Forgetting in Target Language Adaptation of LLMs via Source-Shielded Updates

Atsuki Yamaguchi, Terufumi Morishita, Aline Villavicencio +1

Expanding the linguistic diversity of instruct large language models (LLMs) is crucial for global accessibility but is often hindered by the reliance on costly specialized target l…

cs.CL2025

Deconstructing Attention: Investigating Design Principles for Effective Language Modeling

Huiyin Xue, Nafise Sadat Moosavi, Nikolaos Aletras

The success of Transformer language models is widely credited to their dot-product attention mechanism, which interweaves a set of key design principles: mixing information across…

cs.AI2025

Analysing Chain of Thought Dynamics: Active Guidance or Unfaithful Post-hoc Rationalisation?

Samuel Lewis-Lim, Xingwei Tan, Zhixue Zhao +1

Recent work has demonstrated that Chain-of-Thought (CoT) often yields limited gains for soft-reasoning problems such as analytical and commonsense reasoning. CoT can also be unfait…

cs.CL2025

Optimal Transport Depth Up-Scaling

Mingzi Cao, Xi Wang, Nikolaos Aletras

Pre-training Large Language Models (LLMs) from scratch at larger scales yields remarkable performance but incurs substantially high training costs. Depth up-scaling provides an eff…

cs.CL2025

Enhancing Logical Reasoning in Language Models via Symbolically-Guided Monte Carlo Process Supervision

Xingwei Tan, Marco Valentino, Mahmud Akhter +2

Large language models (LLMs) have shown strong performance in many reasoning benchmarks. However, recent studies have pointed to memorization, rather than generalization, as one of…

cs.CL2025

GreekBarBench: A Challenging Benchmark for Free-Text Legal Reasoning and Citations

Odysseas S. Chlapanis, Dimitrios Galanis, Nikolaos Aletras +1

We introduce GreekBarBench, a benchmark that evaluates LLMs on legal questions across five different legal areas from the Greek Bar exams, requiring citations to statutory articles…

cs.CL2025

Compressing Language Models for Specialized Domains

Miles Williams, George Chrysostomou, Vitor Jeronymo +1

Language models (LMs) excel at tasks across diverse domains, yet require substantial computational resources during inference. Compression techniques such as pruning and quantizati…

cs.CL2024

How Private are Language Models in Abstractive Summarization?

Anthony Hughes, Ning Ma, Nikolaos Aletras

In sensitive domains such as medical and legal, protecting sensitive information is critical, with protective laws strictly prohibiting the disclosure of personal data. This poses…

cs.CL2024

Adapting Chat Language Models Using Only Target Unlabeled Language Data

Atsuki Yamaguchi, Terufumi Morishita, Aline Villavicencio +1

Vocabulary expansion (VE) is the de-facto approach to language adaptation of large language models (LLMs) by adding new tokens and continuing pre-training on target data. While thi…

cs.CL2024

Enhancing Data Quality through Simple De-duplication: Navigating Responsible Computational Social Science Research

Yida Mu, Mali Jin, Xingyi Song +1

Research in natural language processing (NLP) for Computational Social Science (CSS) heavily relies on data from social media platforms. This data plays a crucial role in the devel…

cs.CL2024

Self-calibration for Language Model Quantization and Pruning

Miles Williams, George Chrysostomou, Nikolaos Aletras

Quantization and pruning are fundamental approaches for model compression, enabling efficient inference for language models. In a post-training setting, state-of-the-art quantizati…

cs.CL2024

How Can We Effectively Expand the Vocabulary of LLMs with 0.01GB of Target Language Text?

Atsuki Yamaguchi, Aline Villavicencio, Nikolaos Aletras

Large language models (LLMs) have shown remarkable capabilities in many languages beyond English. Yet, LLMs require more inference steps when generating non-English text due to the…

cs.CL2024★ 1 cited

Who is bragging more online? A large scale analysis of bragging in social media

Mali Jin, Daniel Preoţiuc-Pietro, A. Seza Doğruöz +1

Bragging is the act of uttering statements that are likely to be positively viewed by others and it is extensively employed in human communication with the aim to build a positive…

cs.CL2024

Comparing Explanation Faithfulness between Multilingual and Monolingual Fine-tuned Language Models

Zhixue Zhao, Nikolaos Aletras

In many real natural language processing application scenarios, practitioners not only aim to maximize predictive performance but also seek faithful explanations for the model pred…

cs.CL2024★ 1 cited

An Empirical Study on Cross-lingual Vocabulary Adaptation for Efficient Language Model Inference

Atsuki Yamaguchi, Aline Villavicencio, Nikolaos Aletras

The development of state-of-the-art generative large language models (LLMs) disproportionately relies on English-centric tokenizers, vocabulary and pre-training data. Despite the f…

cs.CL2024★ 1 cited

We Need to Talk About Classification Evaluation Metrics in NLP

Peter Vickers, Loïc Barrault, Emilio Monti +1

In Natural Language Processing (NLP) classification tasks such as topic categorisation and sentiment analysis, model generalizability is generally measured with standard metrics su…