collaborators

14 papers

cs.CL2026

Beyond Perplexity: UTF-8 Validity in Byte-aware Language Models

Sangwhan Moon, Daisuke Oba, Youmi Ma +2

Byte-level tokenization enables language models to handle any Unicode input, but models can generate invalid UTF-8 sequences when encountering rare or unseen characters. We investi…

cs.CL2026

Neuron Level Analysis of Large Language Model in Legal Domain Reasoning

Eri Onami, Youmi Ma, Shuhei Kurita +1

We presented a neuron-level analysis of legal-domain reasoning in LLMs, comparing it with other applied domain tasks across seven open-weight models. Using neuron attribution score…

cs.AI2026

Autoregressive Direct Preference Optimization

Masanari Oi, Mahiro Ukai, Masahiro Kaneko +2

Direct preference optimization (DPO) has emerged as a promising approach for aligning large language models (LLMs) with human preferences. However, the widespread reliance on the r…

cs.CL2026

Aligning Tree-Search Policies with Fixed Token Budgets in Test-Time Scaling of LLMs

Sora Miyamoto, Daisuke Oba, Naoaki Okazaki

Tree-search decoding is an effective form of test-time scaling for large language models (LLMs), but real-world deployment often imposes a fixed per-query token budget that varies…

cs.CL2026

Drifting Objectives for Refining Discrete Diffusion Language Models

Daisuke Oba, Hiroki Furuta, Naoaki Okazaki

Discrete diffusion language models (DDLMs) generate text by iteratively denoising categorical token sequences, while recent drifting methods for continuous generators suggest that…

cs.CL2026

Diffusion-State Policy Optimization for Masked Diffusion Language Models

Daisuke Oba, Hiroki Furuta, Naoaki Okazaki

Masked diffusion language models generate text through iterative masked-token filling, but terminal-only rewards on final completions provide coarse credit assignment for the inter…