Kosuke Sato
Author directory2026
It’s Not RoPE that Creates Sinks: The Role of Self-Concentration and Value-Non-Mixing in Attention
Raito Kiya | Satoki Ohashi | Kosuke Sato | Go Kamoda | Ryosuke Takahashi | Yuji Yamamoto | Daiki Shiono | Keisuke Sakaguchi | Goro Kobayashi
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Raito Kiya | Satoki Ohashi | Kosuke Sato | Go Kamoda | Ryosuke Takahashi | Yuji Yamamoto | Daiki Shiono | Keisuke Sakaguchi | Goro Kobayashi
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Large Language Models (LLMs) often exhibit "Attention Sink" (AS) and the accompanying "Massive Activations" (MAs) at the initial position of a sequence. These phenomena frequently co-occur, and MAs can pose challenges for low-bit quantization. In this study, we analyze the factors underlying AS and MAs that emerge at the initial position regardless of the token occupying it. Our experiments suggest that self-concentration of attention, resulting from the causal mask, and the subsequent Value-non-mixing in attention outputs contribute to AS and MAs. These findings provide new empirical evidence on the internal dynamics of LLMs, offering insights that may inform future quantization strategies and advance our understanding of the internal mechanisms of attention layers.
2025
Can Language Models Handle a Non-Gregorian Calendar? The Case of the Japanese wareki
Mutsumi Sasaki | Go Kamoda | Ryosuke Takahashi | Kosuke Sato | Kentaro Inui | Keisuke Sakaguchi | Benjamin Heinzerling
Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics
Mutsumi Sasaki | Go Kamoda | Ryosuke Takahashi | Kosuke Sato | Kentaro Inui | Keisuke Sakaguchi | Benjamin Heinzerling
Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics
Temporal reasoning and knowledge are essential capabilities for language models (LMs).While much prior work has analyzed and improved temporal reasoning in LMs, most studies have focused solely on the Gregorian calendar.However, many non-Gregorian systems, such as the Japanese, Hijri, and Hebrew calendars, are in active use and reflect culturally grounded conceptions of time.If and how well current LMs can accurately handle such non-Gregorian calendars has not been evaluated so far.Here, we present a systematic evaluation of how well language models handle one such non-Gregorian system: the Japanese wareki.We create datasets that require temporal knowledge and reasoning in using wareki dates. Evaluating open and closed LMs, we find that some models can perform calendar conversions, but GPT-4o, Deepseek V3, and even Japanese-centric models struggle with Japanese calendar arithmetic and knowledge involving wareki dates.Error analysis suggests corpus frequency of Japanese calendar expressions and a Gregorian bias in the model’s knowledge as possible explanations.Our results show the importance of developing LMs that are better equipped for culture-specific tasks such as calendar understanding.
2024
Multi-Criteria Evaluation Framework of Selecting Response-worthy Chats in Live Streaming
Zhantao Lai | Kosuke Sato
Proceedings of the 25th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Zhantao Lai | Kosuke Sato
Proceedings of the 25th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Live streaming, a dynamic medium that merges real-time audiovisual content with interactive text-based chat, presents unique challenges for maintaining viewer engagement and ensuring streamers’ well-being. This study introduces a multi-criteria evaluation framework designed to identify response-worthy chats during live streaming. We proposed a system that evaluates chats based on sentiment polarity and intensity, contextual relevance, and topic uniqueness. We also constructed a dataset annotated by human reviewers who validates the framework, demonstrating a closer alignment with human preferences compared to single-criterion baselines. This framework not only supports the development of more responsive and engaging live streaming environments but also contributes to the broader field of dialog systems by highlighting the distinct needs of real-time, large-scale conversational contexts.