Takashi Shibuya
Author directory2026
Spatio-Temporal Audio Language Modeling for Dynamic Sound Sources
Oh Hyun-Bin | Kazuki Shimada | Yuhta Takida | Kim Sung-Bin | Toshimitsu Uesaka | Takashi Shibuya | Kyeongyoon Lee | Tae-Hyun Oh | Yuki Mitsufuji
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Oh Hyun-Bin | Kazuki Shimada | Yuhta Takida | Kim Sung-Bin | Toshimitsu Uesaka | Takashi Shibuya | Kyeongyoon Lee | Tae-Hyun Oh | Yuki Mitsufuji
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Sound events have semantic identities, locations, and trajectories, yet existing audio-language models typically encode clips as global event content. Conversely, sound event localization models track source directions over time but offer limited semantic coverage for language reasoning. To bridge this gap, we introduce ST-AudioQA, a spatio-temporal audio QA dataset and benchmark built from first-order ambisonic (FOA) renderings of static and moving sound sources. Each scene provides source identity, activity, direction, distance, and motion metadata, enabling dense trajectory supervision and QA about what is sounding, where it is, how it moves, and how sources relate. We further introduce ST-Audio Encoder, which jointly learns event semantics and time-resolved source trajectories, and ST-AudioLM, which exposes these audio tokens to an LLM for spatio-temporal audio QA. Experiments show that this representation improves the balance between semantic preservation and localization and yields stronger reasoning than static spatial and localization-oriented baselines. Beyond the controlled benchmark, ST-AudioLM shows zero-shot transfer to real recordings, with further gains after light adaptation. Project page: https://st-audiolm.github.io/.
2024
Embedded Topic Models Enhanced by Wikification
Takashi Shibuya | Takehito Utsuro
Proceedings of the First Workshop on Advancing Natural Language Processing for Wikipedia
Takashi Shibuya | Takehito Utsuro
Proceedings of the First Workshop on Advancing Natural Language Processing for Wikipedia
Topic modeling analyzes a collection of documents to learn meaningful patterns of words.However, previous topic models consider only the spelling of words and do not take into consideration the polysemy of words.In this study, we incorporate the Wikipedia knowledge into a neural topic model to make it aware of named entities.We evaluate our method on two datasets, 1) news articles of New York Times and 2) the AIDA-CoNLL dataset.Our experiments show that our method improves the performance of neural topic models in generalizability.Moreover, we analyze frequent words in each topic and the temporal dependencies between topics to demonstrate that our entity-aware topic models can capture the time-series development of topics well.
On the Language Encoder of Contrastive Cross-modal Models
Mengjie Zhao | Junya Ono | Zhi Zhong | Chieh-Hsin Lai | Yuhta Takida | Naoki Murata | Wei-Hsiang Liao | Takashi Shibuya | Hiromi Wakaki | Yuki Mitsufuji
Findings of the Association for Computational Linguistics: ACL 2024
Mengjie Zhao | Junya Ono | Zhi Zhong | Chieh-Hsin Lai | Yuhta Takida | Naoki Murata | Wei-Hsiang Liao | Takashi Shibuya | Hiromi Wakaki | Yuki Mitsufuji
Findings of the Association for Computational Linguistics: ACL 2024
Contrastive cross-modal models such as CLIP and CLAP aid various vision-language (VL) and audio-language (AL) tasks. However, there has been limited investigation of and improvement in their language encoder – the central component of encoding natural language descriptions of image/audio into vector representations. We extensively evaluate how unsupervised and supervised sentence embedding training affect language encoder quality and cross-modal task performance. In VL pretraining, we found that sentence embedding training enhances language encoder quality and aids in cross-modal tasks, improving contrastive VL models such as CyCLIP. Sentence embedding training benefits AL tasks when the amount of training data is large. We analyze the representation spaces to understand the strengths of sentence embedding training, and find that it improves text-space uniformity, at the cost of decreased cross-modal alignment.
2023
XMD: An End-to-End Framework for Interactive Explanation-Based Debugging of NLP Models
Dong-Ho Lee | Akshen Kadakia | Brihi Joshi | Aaron Chan | Ziyi Liu | Kiran Narahari | Takashi Shibuya | Ryosuke Mitani | Toshiyuki Sekiya | Jay Pujara | Xiang Ren
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 3: System Demonstrations)
Dong-Ho Lee | Akshen Kadakia | Brihi Joshi | Aaron Chan | Ziyi Liu | Kiran Narahari | Takashi Shibuya | Ryosuke Mitani | Toshiyuki Sekiya | Jay Pujara | Xiang Ren
Proceedings of the 61st Annual Meeting of the Association for Computational Linguistics (Volume 3: System Demonstrations)
NLP models are susceptible to learning spurious biases (i.e., bugs) that work on some datasets but do not properly reflect the underlying task. Explanation-based model debugging aims to resolve spurious biases by showing human users explanations of model behavior, asking users to give feedback on the behavior, thenusing the feedback to update the model. While existing model debugging methods have shown promise, their prototype-level implementations provide limited practical utility. Thus, we propose XMD: the first open-source, end-to-end framework for explanation-based model debugging. Given task- or instance-level explanations,users can flexibly provide various forms of feedback via an intuitive, web-based UI. After receiving user feedback, XMD automatically updates the model in real time, by regularizing the model so that its explanationsalign with the user feedback. The new model can then be easily deployed into real-world applications via Hugging Face. Using XMD, we can improve the model’s OOD performance on text classification tasks by up to 18%.
2022
Good Examples Make A Faster Learner: Simple Demonstration-based Learning for Low-resource NER
Dong-Ho Lee | Akshen Kadakia | Kangmin Tan | Mahak Agarwal | Xinyu Feng | Takashi Shibuya | Ryosuke Mitani | Toshiyuki Sekiya | Jay Pujara | Xiang Ren
Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Dong-Ho Lee | Akshen Kadakia | Kangmin Tan | Mahak Agarwal | Xinyu Feng | Takashi Shibuya | Ryosuke Mitani | Toshiyuki Sekiya | Jay Pujara | Xiang Ren
Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Recent advances in prompt-based learning have shown strong results on few-shot text classification by using cloze-style templates. Similar attempts have been made on named entity recognition (NER) which manually design templates to predict entity types for every text span in a sentence. However, such methods may suffer from error propagation induced by entity span detection, high cost due to enumeration of all possible text spans, and omission of inter-dependencies among token labels in a sentence. Here we present a simple demonstration-based learning method for NER, which lets the input be prefaced by task demonstrations for in-context learning. We perform a systematic study on demonstration strategy regarding what to include (entity examples, with or without surrounding context), how to select the examples, and what templates to use. Results on in-domain learning and domain adaptation show that the model’s performance in low-resource settings can be largely improved with a suitable demonstration strategy (e.g., a 4-17% improvement on 25 train instances). We also find that good demonstration can save many labeled examples and consistency in demonstration contributes to better performance.
2020
Nested Named Entity Recognition via Second-best Sequence Learning and Decoding
Takashi Shibuya | Eduard Hovy
Transactions of the Association for Computational Linguistics, Volume 8
Takashi Shibuya | Eduard Hovy
Transactions of the Association for Computational Linguistics, Volume 8
When an entity name contains other names within it, the identification of all combinations of names can become difficult and expensive. We propose a new method to recognize not only outermost named entities but also inner nested ones. We design an objective function for training a neural model that treats the tag sequence for nested entities as the second best path within the span of their parent entity. In addition, we provide the decoding method for inference that extracts entities iteratively from outermost ones to inner ones in an outside-to-inside way. Our method has no additional hyperparameters to the conditional random field based model widely used for flat named entity recognition tasks. Experiments demonstrate that our method performs better than or at least as well as existing methods capable of handling nested entities, achieving F1-scores of 85.82%, 84.34%, and 77.36% on ACE-2004, ACE-2005, and GENIA datasets, respectively.
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Co-authors
- Akshen Kadakia 2
- Dong-Ho Lee 2
- Ryosuke Mitani 2
- Yuki Mitsufuji 2
- Jay Pujara 2
- Xiang Ren 2
- Toshiyuki Sekiya 2
- Yuhta Takida 2
- Mahak Agarwal 1
- Aaron Chan 1
- Xinyu Feng 1
- Eduard Hovy 1
- Oh Hyun-Bin 1
- Brihi Joshi 1
- Chieh-Hsin Lai 1
- Kyeongyoon Lee 1
- Wei-Hsiang Liao 1
- Ziyi Liu 1
- Naoki Murata 1
- Kiran Narahari 1
- Tae-Hyun Oh 1
- Junya Ono 1
- Kazuki Shimada 1
- Kim Sung-Bin 1
- Kangmin Tan 1
- Toshimitsu Uesaka 1
- Takehito Utsuro 1
- Hiromi Wakaki 1
- Mengjie Zhao 1
- Zhi Zhong 1