activity
20232026
collaborators

14 papers

cs.CR2026

Fetch Me If You Can: A Comprehensive Analysis of Fetch Metadata

Pedro Bernardo, Alex Ploner, Marco Squarcina +2

Effective server-side defenses against cross-site attacks depend on understanding the context in which browser requests are generated. However, servers often lack the information n…

cs.CL2026

Last Translation Benchmark

Vilém Zouhar, Niyati Bafna, Mukund Choudhary +263

For scientific progress, we need benchmarks that test the limits of state-of-the-art models, and evaluation methods that inform us about failure cases. As models get stronger, stan…

cs.CL2026

Scaling Unsupervised Word Alignment to Documents via Structural Constraints

Michelle Wastl, Jannis Vamvas, Rico Sennrich

Word alignment has traditionally been studied between sentences, but many cross-lingual tasks increasingly require correspondences across full documents. While recent multilingual…

cs.CL2026

Reinforcement Learning Elicits Contextual Learning of Unseen Language Translation

Hanxu Hu, Zdeněk Šnajdr, Pinzhen Chen +2

Prior work has shown that large language models (LLMs) can translate unseen or low-resource languages by undergoing continued training or even by encoding a grammar book in their c…

cs.CL2026

DeReason: A Difficulty-Aware Curriculum Improves Decoupled SFT-then-RL Training for General Reasoning

Hanxu Hu, Yuxuan Wang, Maggie Huan +4

Reinforcement learning with Verifiable Rewards (RLVR) has emerged as a powerful paradigm for eliciting reasoning capabilities in large language models, particularly in mathematics…

cs.CL2026

Translation Asymmetry in LLMs as a Data Augmentation Factor: A Case Study for 6 Romansh Language Varieties

Jannis Vamvas, Ignacio Pérez Prat, Angela Heldstab +3

Recent strategies for low-resource machine translation rely on LLMs to generate synthetic data based on text in higher-resource languages. We revisit this idea for Romansh, a langu…

cs.CL2025

Expanding the WMT24++ Benchmark with Rumantsch Grischun, Sursilvan, Sutsilvan, Surmiran, Puter, and Vallader

Jannis Vamvas, Ignacio Pérez Prat, Not Battesta Soliva +14

The Romansh language, spoken in Switzerland, has limited resources for machine translation evaluation. In this paper, we present a benchmark for six varieties of Romansh: Rumantsch…

cs.CL2025

Apertus: Democratizing Open and Compliant LLMs for Global Language Environments

Project Apertus, Alejandro Hernández-Cano, Alexander Hägele +100

We present Apertus, a fully open suite of large language models (LLMs) designed to address two systemic shortcomings in today's open model ecosystem: data compliance and multilingu…

cs.CL2025

Leveraging In-Context Learning for Political Bias Testing of LLMs

Patrick Haller, Jannis Vamvas, Rico Sennrich +1

A growing body of work has been querying LLMs with political questions to evaluate their potential biases. However, this probing method has limited stability, making comparisons be…

cs.CL2024

Fine-tuning the SwissBERT Encoder Model for Embedding Sentences and Documents

Juri Grosjean, Jannis Vamvas

Encoder models trained for the embedding of sentences or short documents have proven useful for tasks such as semantic search and topic modeling. In this paper, we present a versio…

cs.CL2024

Linear-time Minimum Bayes Risk Decoding with Reference Aggregation

Jannis Vamvas, Rico Sennrich

Minimum Bayes Risk (MBR) decoding is a text generation technique that has been shown to improve the quality of machine translations, but is expensive, even if a sampling-based appr…

cs.CL2024

Modular Adaptation of Multilingual Encoders to Written Swiss German Dialect

Jannis Vamvas, Noëmi Aepli, Rico Sennrich

Creating neural text encoders for written Swiss German is challenging due to a dearth of training data combined with dialectal variation. In this paper, we build on several existin…

cs.CL2024

Machine Translation Models are Zero-Shot Detectors of Translation Direction

Michelle Wastl, Jannis Vamvas, Rico Sennrich

Detecting the translation direction of parallel text has applications for machine translation training and evaluation, but also has forensic applications such as resolving plagiari…

cs.CL2023

Trained MT Metrics Learn to Cope with Machine-translated References

Jannis Vamvas, Tobias Domhan, Sony Trenous +2

Neural metrics trained on human evaluations of MT tend to correlate well with human judgments, but their behavior is not fully understood. In this paper, we perform a controlled ex…