TOMOYUKI KAJIWARA
kajiwara [at] cs.ehime-u.ac.jp ⋄ https://sites.google.com/site/moguranosenshi/
Department of Computer Science, Ehime University#607, 4th Bldg. of Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, JapanRESEARCH INTERESTSNatural Language Processing (Paraphrasing, Text Simplification, Quality Estimation)
POSITION
Senior Assistant Professor
January 2024 - present
Artificial Intelligence Lab., Graduate School of Science and Engineering, Ehime University
Assistant Professor
January 2021 - December 2023
Artificial Intelligence Lab., Graduate School of Science and Engineering, Ehime University
Specially-Appointed Assistant Professor
April 2018 - December 2020
Intelligence and Sensing Lab., Institute for Datability Science, Osaka University
EDUCATION
Ph.D. in Engineering
April 2015 - March 2018
Dept. of System Design, Tokyo Metropolitan University
Text Simplification without Simplified Corpora (Supervisor: Mamoru Komachi)
Ph.D. Thesis Recommended by IPSJ SIGs
B.S. and M.S. in Engineering
April 2011 - March 2015
Dept. of Electrical, Electronics and Information Engineering, Nagaoka University of Technology
Lexical Simplification for Reading Assistance (Supervisor: Kazuhide Yamamoto)Department Chair’s Award
EXPERIENCE
Visiting Researcher
NICT (Mentor: Atsushi Fujita)
University of Liverpool (Mentor: Danushka Bollegala)InternshipBrainPad, Inc.
Fujitsu Laboratories, Ltd.
Editorial Committee
Journal of Natural Language Processing

May 2017 - August 2017
September 2015 - December 2015
January 2014 - February 2014
October 2012 - February 2013
March 2020 - March 2024

Program Committee
Chair: YANS (2022-2023)
Local Arrangement Chair: SNL (2020)
Program Committee: NLP (2022-2023), JSAI (2019-2020), IPSJ-SIGNL (2022-), YANS (2015-2016)
Reviewer
ACL-2023, EMNLP-2022, COLING-2022, AACL-2022, LREC-2022, ACLSRW-2022,
TSAR-2022, AAAI-2021, ACL-2021, EMNLP-2021, NAACL-2021, EACL-2021, ACLSRW-2021,
NAACLSRW-2021, AAAI-2020, IJCAI-2020, ACL-2020, EMNLP-2020, COLING-2020,
AACL-2020, ACLSRW-2020, BEA-2020, AACLSRW-2020, ACL-2019, EMNLP-2019,
NAACL-2019, PACLIC-2019, NLPTEA-2018, IJCNLP-2017, NLPTEA-2017

GRANTSJSPS, Grant-in-Aid for Young Scientists (24K20840)
Complex Text Generation with Style Control
Principal Investigator: 3,600,000 JPY

April 2024 - March 2027

JSPS, Grant-in-Aid for Young Scientists (20K19861)
Semi-supervised Machine Translation based on Quality Estimation
Principal Investigator: 3,100,000 JPY

April 2020 - March 2024

JST, ACT-X (JPMJAX1907)
October 2019 - March 2022
Paraphrase Generation for Improving the Performance of Various NLP Applications
Principal Investigator: 4,500,000 JPY
JST, ACT-I (JPMJPR18UB)
Personalized Text Generation with Lexical Constraint
Principal Investigator: 4,000,000 JPY

October 2018 - March 2020

JSPS, Grant-in-Aid for Research Activity Start-up (18H06465)
Machine Translation based on Multimodal Quality Estimation
Principal Investigator: 2,100,000 JPY

August 2018 - March 2020

JSPS, Grant-in-Aid for Scientific Research (C) (24K13195)
April 2024 - March 2027
Development of an AI System That Uses Images and Natural Language as Input and Interacts with
Clinicians to Create Orthodontic Diagnoses.
Co-Investigator: 3,600,000 JPY (PI: Chihiro Tanikawa)
JSPS, Grant-in-Aid for Scientific Research (B) (22H03651)
April 2022 - March 2025
Construction of an Evaluation Dataset and Quality Estimation for Neural Language Generation
Co-Investigator: 13,400,000 JPY (PI: Mamoru Komachi)
JSPS, Grant-in-Aid for Scientific Research (B) (21H03564)
語彙学習のための大規模 Data-Driven Learning システム開発
Co-Investigator: 13,100,000 JPY (PI: Yuki Arase)

April 2021 - March 2025

JSPS, Grant-in-Aid for Scientific Research (B) (20H04484)
Scholar2Vec: 研究者の多様な活動情報を埋め込める深層潜在空間の構築
Co-Investigator: 13,900,000 JPY (PI: Marie Katsurai)

April 2020 - March 2024

JSPS, Grant-in-Aid for Scientific Research (B) (19H01330)
April 2019 - March 2023
Historical Anatomy of Public Opinion Making in Australia: Public Meeting Data Analysis via NLP
Co-Investigator: 13,300,000 JPY (PI: Takao Fujikawa)
PUBLICATIONS
Selected Publications (AAAI, ACL, EMNLP, NAACL, COLING, AACL)• Ryota Miyano, Tomoyuki Kajiwara and Yuki Arase. Self-Ensembling of N -best Generation
Hypotheses by Lexically Constrained Decoding. EMNLP 2023. (Acceptance Rate: 14%)
• Yuki Arase, Satoru Uchida and Tomoyuki Kajiwara. CEFR-Based Sentence-Diﬃculty Annotation and Assessment. EMNLP 2022. (Acceptance Rate: 20%)
• Daiki Yanamoto, Tomoki Ikawa, Tomoyuki Kajiwara, Takashi Ninomiya, Satoru Uchida and Yuki
Arase. Controllable Text Simplification with Deep Reinforcement Learning. AACLIJCNLP 2022. (Acceptance Rate: 27%)
• Yuto Kuroda, Tomoyuki Kajiwara, Yuki Arase and Takashi Ninomiya. Adversarial Training
on Disentangling Meaning and Language Representations for Unsupervised Quality
Estimation. COLING 2022. (Acceptance Rate: 24%)

• Han Huang, Tomoyuki Kajiwara and Yuki Arase. Definition Modelling for Appropriate
Specificity. EMNLP 2021. (Acceptance Rate: 26%)
• Nattapong Tiyajamorn, Tomoyuki Kajiwara, Yuki Arase and Makoto Onizuka. Language-agnostic
Representation from Multilingual Sentence Encoders for Cross-lingual Similarity Estimation. EMNLP 2021. (Acceptance Rate: 26%)
• Sora Ohashi, Junya Takayama, Tomoyuki Kajiwara and Yuki Arase. Distinct Label Representations for Few-Shot Text Classification. ACL 2021. (Acceptance Rate: 21%)
• Tomoyuki Kajiwara, Chenhui Chu, Noriko Takemura, Yuta Nakashima and Hajime Nagahara.
WRIME: A New Dataset for Emotional Intensity Estimation with Subjective andObjective Annotations. NAACL 2021. (Acceptance Rate: 26%)
• Sora Ohashi, Mao Isogawa, Tomoyuki Kajiwara and Yuki Arase. Tiny Word Embeddings
Using Globally Informed Reconstruction. COLING 2020. (Acceptance Rate: 26%)
• Ryoma Yoshimura, Masahiro Kaneko, Tomoyuki Kajiwara and Mamoru Komachi. SOME: Reference-less Sub-Metrics Optimized for Manual Evaluations of Grammatical Error
Correction. COLING 2020. (Acceptance Rate: 26%)
• Sora Ohashi, Junya Takayama, Tomoyuki Kajiwara, Chenhui Chu and Yuki Arase. Text Classification with Negative Supervision. ACL 2020. (Acceptance Rate: 18%)
• Tomoyuki Kajiwara, Biwa Miura and Yuki Arase. Monolingual Transfer Learning via Bilingual Translators for Style-Sensitive Paraphrase Generation. AAAI 2020. (Acceptance
Rate: 21%)
• Tomoyuki Kajiwara. Negative Lexically Constrained Decoding for Paraphrase Generation. ACL 2019. (Acceptance Rate: 18%)
• Tomoyuki Kajiwara and Mamoru Komachi. Building a Monolingual Parallel Corpus for
Text Simplification Using Sentence Similarity Based on Alignment between Word
Embeddings. COLING 2016. (Acceptance Rate: 32%)
Journal Papers
1. Satoru Uchida, Yuki Arase and Tomoyuki Kajiwara. Profiling English Sentences Based on
CEFR Levels. International Journal of Applied Linguistics, 2024. (to appear)
2. Yuya Ogasa, Tomoyuki Kajiwara and Yuki Arase. Data Augmentation by Paraphrasing
with Controllable Semantic and Surface Similarities. Journal of Natural Language Processing, Vol.31, No.4, pp.xxx–xxx, 2024. (to appear)
3. Ryota Miyano, Tomoyuki Kajiwara and Yuki Arase. Self-Ensemble: Integration of N -best
Hypotheses by Lexically Constrained Decoding. Journal of Natural Language Processing,
Vol.31, No.2, pp.680–706, 2024. (In Japanese)
4. Rina Miyata, Hyuga Koretaka, Hiroki Yamauchi, Daiki Yanamoto, Tomoyuki Kajiwara, Takashi
Ninomiya and Yasuhiro Nishiwaki. MATCHA: Parallel Corpus for Japanese Text Simplification Based on Professionally Simplified Articles. Journal of Natural Language Processing, Vol.31, No.2, pp.590–609, 2024. (In Japanese)
5. Kazuki Tani, Akihiro Tamura, Tomoyuki Kajiwara, Takashi Ninomiya and Tsuneo Kato. Japaneseto-English Multi-Level Complexity-Controllable MT: Test Data and Multi-ReferenceBased Learning. Journal of Natural Language Processing, Vol.31, No.2, pp.456–478, 2024. (InJapanese)6. Sora Tarumoto, Koki Hatagaki, Rina Miyata, Tomoyuki Kajiwara and Takashi Ninomiya. Evaluating ChatGPT’s Ability to Generate Japanese. Journal of Natural Language Processing,
Vol.31, No.2, pp.349–373, 2024. (In Japanese)
7. Risa Kondo, Reon Kajikawa Tomoyuki Kajiwara and Takashi Ninomiya. Characterizing ChatOriented Dialogue System via Style Transfer. Journal of Information Processing Society ofJapan, Vol.65, No.3, pp.657–666, 2024. (In Japanese)
8. Tatsuya Zetsu, Tomoyuki Kajiwara and Yuki Arase. Controllable Text Simplification Using
Lexically Constrained Decoding Based on Edit Operation Prediction. Journal of Natural
Language Processing, Vol.30, No.3, pp.991–1010, 2023. (In Japanese)
9. Koji Tanaka, Chenhui Chu, Tomoyuki Kajiwara, Yuta Nakashima, Noriko Takemura, Hajime
Nagahara and Takao Fujikawa. Corpus Construction for Historical Newspapers: A Case
Study on Public Meeting Corpus Construction using OCR Error Correction. SN
Computer Science, Vol.3, No.489, pp.1–17, 2022.
10. Kazuki Akiyama, Akihiro Tamura, Takashi Ninomiya and Tomoyuki Kajiwara. Hie-BART: Abstractive Summarization by Hierarchical BART. Journal of Natural Language Processing,Vol.29, No.3, pp.835–853, 2022. (In Japanese)
11. Yuujin Shimizu, Chihiro Tanikawa, Tomoyuki Kajiwara, Hajime Nagahara, Takashi Yamashiro.
The Validation of Orthodontic Artificial Intelligence Systems That Perform Orthodontic Diagnoses and Treatment Planning. European Journal of Orthodontics, Vol.44, No.4,
pp.436–444, 2022.
12. Tetsuro Nishihara, Yuji Iwamoto, Masato Yoshinaka, Tomoyuki Kajiwara, Yuki Arase and Takashi
Ninomiya. Unsupervised Quality Estimation via Multilingual Denoising Autoencoder.
Journal of Natural Language Processing, Vol.29, No.2, pp.669–687, 2022. (In Japanese)
13. Junya Takayama, Tomoyuki Kajiwara and Yuki Arase. Construction and Analysis of a Dialogue Corpus with Paraphrase Pairs of Indirect and Direct Responses. Journal of
Natural Language Processing, Vol.29, No.1, pp.84–111, 2022. (In Japanese)
Outstanding Paper Award
14. Yuting Zhao, Mamoru Komachi, Tomoyuki Kajiwara, Chenhui Chu. Region-Attentive Multimodal Neural Machine Translation. Neurocomputing, Vol.476, pp.1–13, 2022.
15. Yuting Zhao, Mamoru Komachi, Tomoyuki Kajiwara, Chenhui Chu. Word-Region AlignmentGuided Multimodal Neural Machine Translation. IEEE/ACM Transactions on Audio,
Speech and Language Processing, Vol.30, pp.244–259, 2021.
16. Masato Yoshinaka, Tomoyuki Kajiwara and Yuki Arase. Monolingual Phrase Alignment
Based on Word Embedding. Journal of Natural Language Processing, Vol.28, No.2, pp.508–
531, 2021. (In Japanese)
17. Ryoma Yoshimura, Masahiro Kaneko, Tomoyuki Kajiwara and Mamoru Komachi. Optimizationof Reference-less Evaluation Metric of Grammatical Error Correction for Manual
Evaluations. Journal of Natural Language Processing, Vol.28, No.2, pp.404–427, 2021. (InJapanese)
18. Sora Ohashi, Mao Isogawa, Tomoyuki Kajiwara and Yuki Arase. Compact Word Embeddings
Based on Global Similarity. Journal of Natural Language Processing, Vol.28, No.1, pp.235–
252, 2021. (In Japanese)
19. Tomoyuki Kajiwara, Daiki Nishihara, Tomonori Kodaira and Mamoru Komachi. Language Resources for Japanese Lexical Simplification. Journal of Natural Language Processing, Vol.27,
No.4, pp.801–824, 2020. (In Japanese)20. Daiki Nishihara, Tomoyuki Kajiwara and Yuki Arase. Controllable Text Simplification with
Lexical Constraint. Journal of Natural Language Processing, Vol.27, No.2, pp.189–210, 2020.
(In Japanese)
21. Takao Fujikawa, Chenhui Chu, Tomoyuki Kajiwara and Hajime Nagahara. Use of Big Data in
Historical Research: Cases of Australia. Seiyoshigaku (The Studies in Western History),
No.268, pp.50–61, 2019. (In Japanese)
22. Kazuki Ashihara, Tomoyuki Kajiwara, Yuki Arase and Satoru Uchida. Contextualized MultiSense Word Embedding. Journal of Natural Language Processing, Vol.26, No.4, pp.689–710,
2019. (In Japanese)
23. Hiroki Shimanaka, Tomoyuki Kajiwara and Mamoru Komachi. Metric for Automatic Machine Translation Evaluation based on Pre-trained Sentence Embeddings. Journal of
Natural Language Processing, Vol.26, No.3, pp.613–634, 2019. (In Japanese)
24. Tomoyuki Kajiwara and Mamoru Komachi. Text Simplification without Simplified Corpora. Journal of Natural Language Processing, Vol.25, No.2, pp.223–249, 2018. (In Japanese)
Best Paper Award
25. Tomoyuki Kajiwara, Danushka Bollegala, Yuichi Yoshida and Ken-ichi Kawarabayashi. An Iterative Approach for the Global Estimation of Sentence Similarity. PLOS ONE, Vol.12,
No.9, pp.1–15, 2017.
26. Tomoyuki Kajiwara and Kazuhide Yamamoto. Japanese Lexical Simplification for Children
Using Definition Statements. Journal of Information Processing Society of Japan, Vol.56,
No.3, pp.983–992, 2015. (In Japanese)
Refereed Conference Papers
1. Ayu Teramen, Takumi Ohtsuka, Risa Kondo, Tomoyuki Kajiwara and Takashi Ninomiya. Englishto-Japanese Multimodal Machine Translation Based on Image-Text Matching of Lecture Videos. In Proceedings of the 3rd Workshop on Advances in Language and Vision Research(ALVR 2024), pp.xxx-xxx, 2024. (to appear)
2. Reon Kajikawa, Keiichiro Yamada, Tomoyuki Kajiwara and Takashi Ninomiya. Multi-Source
Text Classification for Multilingual Sentence Encoder with Machine Translation. In
Proceedings of the NAACL 2024 Student Research Workshop (NAACL 2024 SRW), pp.226-232,
2024. (Acceptance Rate: 60%)
3. Koki Horiguchi, Tomoyuki Kajiwara, Yuki Arase and Takashi Ninomiya. Evaluation Dataset
for Japanese Medical Text Simplification. In Proceedings of the NAACL 2024 Student
Research Workshop (NAACL 2024 SRW), pp.219-225, 2024. (Acceptance Rate: 60%)
4. Soichiro Sugihara, Tomoyuki Kajiwara, Takashi Ninomiya, Shoko Wakamiya and Eiji Aramaki.
Semi-automatic Construction of a Word Complexity Lexicon for Japanese Medical
Terminology. In Proceedings of the 6th Clinical Natural Language Processing Workshop, pp.329333, 2024. (Acceptance Rate: 60%)
5. Yuki Hironaka, Tomoyuki Kajiwara and Takashi Ninomiya. Transfer Fine-tuning for Quality
Estimation of Text Simplification. In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024),
pp.16738-16744, 2024. (Acceptance Rate: 52%)

6. Hiroto Kaino, Soichiro Sugihara, Tomoyuki Kajiwara, Takashi Ninomiya, Joshua Tanner andShonosuke Ishiwatari. Utilizing Longer Context than Speech Bubbles in AutomatedManga Translation. In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024), pp.17337-17342,
2024. (Acceptance Rate: 52%)
7. Daichi Yamaguchi, Rei Miyata, Atsushi Fujita, Tomoyuki Kajiwara and Satoshi Sato. Automatic
Decomposition of Text Editing Examples into Primitive Edit Operations: Toward
Analytic Evaluation of Editing Systems. In Proceedings of the 2024 Joint International
Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING
2024), pp.1899-1914, 2024. (Acceptance Rate: 52%)
8. Yuya Ogasa, Tomoyuki Kajiwara and Yuki Arase. Controllable Paraphrase Generation for
Semantic and Lexical Similarities. In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024),
pp.3927-3942, 2024. (Acceptance Rate: 52%)
9. Ryota Miyano, Tomoyuki Kajiwara and Yuki Arase. Self-Ensembling of N -best Generation
Hypotheses by Lexically Constrained Decoding. In Proceedings of the 2023 Conferenceon Empirical Methods in Natural Language Processing (EMNLP 2023), pp.14653–14661, 2023.
(Acceptance Rate: 14%)
10. Hyuga Koretaka, Tomoyuki Kajiwara, Atsushi Fujita and Takashi Ninomiya. Mitigating Domain Mismatch in Machine Translation via Paraphrasing. In Proceedings of the 10th
Workshop on Asian Translation (WAT 2023), pp.29–40, 2023. (Acceptance Rate: ??%)
11. Takumi Ohtsuka, Tomoyuki Kajiwara, Chihiro Tanikawa, Yuujin Shimizu, Hajime Nagahara andTakashi Ninomiya. Automated Orthodontic Diagnosis from a Summary of Medical Findings. In Proceedings of the 5th Clinical Natural Language Processing Workshop, pp.156–160,
2023. (Acceptance Rate: 71%)
12. Nana Yoshimi, Tomoyuki Kajiwara, Satoru Uchida, Yuki Arase and Takashi Ninomiya. Distractor Generation for Fill-in-the-Blank Exercises by Question Type. In Proceedings of the
ACL 2023 Student Research Workshop (ACL 2023 SRW), pp.276–281, 2023. (Acceptance Rate:
34%)
13. Ryoya Yuasa, Akihiro Tamura, Tomoyuki Kajiwara, Takashi Ninomiya and Tsuneo Kato. Multimodal Neural Machine Translation Using Synthetic Images Transformed by Latent
Diﬀusion Model. In Proceedings of the ACL 2023 Student Research Workshop (ACL 2023
SRW), pp.76–82, 2023. (Acceptance Rate: 34%)
14. Koki Hatagaki, Tomoyuki Kajiwara and Takashi Ninomiya. Parallel Corpus Filtering forJapanese Text Simplification. In Proceedings of the Workshop on Text Simplification, Accessibility, and Readability (TSAR 2022), pp.12–18, 2022. (Acceptance Rate: 56%)
15. Tatsuya Zetsu, Tomoyuki Kajiwara and Yuki Arase. Lexically Constrained Decoding with
Edit Operation Prediction for Controllable Text Simplification. In Proceedings of theWorkshop on Text Simplification, Accessibility, and Readability (TSAR 2022), pp.147–153, 2022.
(Acceptance Rate: 56%)
16. Akio Hayakawa, Tomoyuki Kajiwara, Hiroki Ouchi and Taro Watanabe. JADES: New Text
Simplification Dataset in Japanese Targeted at Non-Native Speakers. In Proceedingsof the Workshop on Text Simplification, Accessibility, and Readability (TSAR 2022), pp.179–187,
2022. (Acceptance Rate: 56%)
17. Yuki Arase, Satoru Uchida and Tomoyuki Kajiwara. CEFR-Based Sentence-Diﬃculty Annotation and Assessment. In Proceedings of the 2022 Conference on Empirical Methods in
Natural Language Processing (EMNLP 2022), pp.6206–6219, 2022. (Acceptance Rate: 20%)

18. Kaori Abe, Sho Yokoi, Tomoyuki Kajiwara and Kentaro Inui. Why Sentence Similarity
Benchmark Is Not Predictive of Application-oriented Task Performance? In Proceedings of the 3rd Workshop on Evaluation and Comparison of NLP Systems (Eval4NLP 2022),
pp.70–87, 2022. (Acceptance Rate: 55%)
19. Haruya Suzuki, Sora Tarumoto, Tomoyuki Kajiwara, Takashi Ninomiya, Yuta Nakashima andHajime Nagahara. Emotional Intensity Estimation based on Writer’s Personality. In
Proceedings of the AACL-IJCNLP 2022 Student Research Workshop (AACL-IJCNLP 2022 SRW),
pp.1–7, 2022. (Acceptance Rate: 40%)
20. Daiki Yanamoto, Tomoki Ikawa, Tomoyuki Kajiwara, Takashi Ninomiya, Satoru Uchida and Yuki
Arase. Controllable Text Simplification with Deep Reinforcement Learning. In Proceedings of the 2nd Conference of the Asia-Pacific Chapter of the Association for Computational
Linguistics and the 12th International Joint Conference on Natural Language Processing (AACLIJCNLP 2022), pp.398–404, 2022. (Acceptance Rate: 27%)
21. Hiroki Yamauchi, Tomoyuki Kajiwara, Marie Katsurai, Ikki Ohmukai and Takashi Ninomiya. A
Japanese Masked Language Model for Academic Domain. In Proceedings of the Third
Workshop on Scholarly Document Processing (SDP 2022), pp.152–157, 2022. (Acceptance Rate:??%)
22. Yuki Nakatani, Tomoyuki Kajiwara and Takashi Ninomiya. Comparing BERT-based Reward
Functions for Deep Reinforcement Learning in Machine Translation. In Proceedings of
the 9th Workshop on Asian Translation (WAT 2022), 2022. (Acceptance Rate: ??%)
23. Yuto Kuroda, Tomoyuki Kajiwara, Yuki Arase and Takashi Ninomiya. Adversarial Training
on Disentangling Meaning and Language Representations for Unsupervised Quality
Estimation. In Proceedings of the 29th International Conference on Computational Linguistics(COLING 2022), pp.5240–5245, 2022. (Acceptance Rate: 24%)
24. Han Huang, Tomoyuki Kajiwara and Yuki Arase. JADE: Corpus for Japanese Definition
Modelling. In Proceedings of the 13th International Conference on Language Resources and
Evaluation (LREC 2022), pp.6884–6888, 2022. (Acceptance Rate: 64%)
25. Kazuki Tani, Ryoya Yuasa, Kazuki Takikawa, Akihiro Tamura, Tomoyuki Kajiwara, Takashi Ninomiya and Tsuneo Kato. A Benchmark Dataset for Multi-Level Complexity-Controllable
Machine Translation. In Proceedings of the 13th International Conference on Language Resources and Evaluation (LREC 2022), pp.6744–6752, 2022. (Acceptance Rate: 64%)
26. Haruya Suzuki, Yuto Miyauchi, Kazuki Akiyama, Tomoyuki Kajiwara, Takashi Ninomiya, Noriko
Takemura, Yuta Nakashima and Hajime Nagahara. A Japanese Dataset for Subjective andObjective Sentiment Polarity Classification in Micro Blog Domain. In Proceedings ofthe 13th International Conference on Language Resources and Evaluation (LREC 2022), pp.7022–
7028, 2022. (Acceptance Rate: 64%)
27. Han Huang, Tomoyuki Kajiwara and Yuki Arase. Definition Modelling for Appropriate
Specificity. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language
Processing (EMNLP 2021), pp.2499–2509, 2021. (Acceptance Rate: 26%)
28. Nattapong Tiyajamorn, Tomoyuki Kajiwara, Yuki Arase and Makoto Onizuka. Language-agnostic
Representation from Multilingual Sentence Encoders for Cross-lingual Similarity Estimation. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language
Processing (EMNLP 2021), pp.7764–7774, 2021. (Acceptance Rate: 26%)
29. Yuki Arase and Tomoyuki Kajiwara. Distilling Word Meaning in Context from Pretrained Language Model. In Findings of the Association for Computational Linguistics:
EMNLP 2021, pp.534–546, 2021. (Acceptance Rate: 37%)

30. Junya Takayama, Tomoyuki Kajiwara and Yuki Arase. DIRECT: Direct and Indirect Responses in Conversational Text Corpus. In Findings of the Association for Computational
Linguistics: EMNLP 2021, pp.1980–1989, 2021. (Acceptance Rate: 37%)
31. Sora Kadotani, Tomoyuki Kajiwara, Yuki Arase and Makoto Onizuka. Edit Distance Based
Curriculum Learning for Paraphrase Generation. In Proceedings of the ACL-IJCNLP
2021 Student Research Workshop (ACL-IJCNLP 2021 SRW), pp.229–234, 2021. (Acceptance
Rate: 39%)
32. Sora Ohashi, Junya Takayama, Tomoyuki Kajiwara and Yuki Arase. Distinct Label Representations for Few-Shot Text Classification. In Proceedings of the Joint Conference of the 59th
Annual Meeting of the Association for Computational Linguistics and the 11th International Joint
Conference on Natural Language Processing (ACL-IJCNLP 2021), pp.831–836, 2021. (Acceptance
Rate: 21%)
33. Tomoyuki Kajiwara, Chenhui Chu, Noriko Takemura, Yuta Nakashima and Hajime Nagahara.
WRIME: A New Dataset for Emotional Intensity Estimation with Subjective andObjective Annotations. In Proceedings of the 2021 Annual Conference of the North American
Chapter of the Association for Computational Linguistics (NAACL 2021), pp.2095–2104, 2021.
(Acceptance Rate: 26%)
34. Akifumi Nakamachi, Tomoyuki Kajiwara and Yuki Arase. Text Simplification with Reinforcement Learning using Supervised Rewards on Grammaticality, Meaning Preservation, and Simplicity. In Proceedings of the AACL-IJCNLP 2020 Student Research Workshop(AACL-IJCNLP 2020 SRW), pp.153–159, 2020. (Acceptance Rate: 51%)
35. Sora Ohashi, Mao Isogawa, Tomoyuki Kajiwara and Yuki Arase. Tiny Word Embeddings Using Globally Informed Reconstruction. In Proceedings of the 28th International Conference
on Computational Linguistics (COLING 2020), pp.1199–1203, 2020. (Acceptance Rate: 26%)
36. Ryoma Yoshimura, Masahiro Kaneko, Tomoyuki Kajiwara and Mamoru Komachi. SOME: Reference-less Sub-Metrics Optimized for Manual Evaluations of Grammatical Error
Correction. In Proceedings of the 28th International Conference on Computational Linguistics(COLING 2020), pp.6516–6522, 2020. (Acceptance Rate: 26%)
37. Yuting Zhao, Mamoru Komachi, Tomoyuki Kajiwara and Chenhui Chu. Double Attentionbased Multimodal Neural Machine Translation with Semantic Image Regions. In
Proceedings of the 22nd Annual Conference of the European Association for Machine Translation(EAMT 2020), pp.105–114, 2020. (Acceptance Rate: 53%)
38. Sora Ohashi, Junya Takayama, Tomoyuki Kajiwara, Chenhui Chu and Yuki Arase. Text Classification with Negative Supervision. In Proceedings of the 58th Annual Meeting of the
Association for Computational Linguistics (ACL 2020), pp.351–357, 2020. (Acceptance Rate:
18%)
39. Yuki Arase, Tomoyuki Kajiwara and Chenhui Chu. Annotation of Adverse Drug Reactionsin Patients’ Weblogs. In Proceedings of the 12th International Conference on Language Resources and Evaluation (LREC 2020), pp.6771–6778, 2020. (Acceptance Rate: 60%)
40. Daiki Nishihara and Tomoyuki Kajiwara. Word Complexity Estimation for Japanese Lexical Simplification. In Proceedings of the 12th International Conference on Language Resources
and Evaluation (LREC 2020), pp.3107–3113, 2020. (Acceptance Rate: 60%)
41. Masato Yoshinaka, Tomoyuki Kajiwara and Yuki Arase. SAPPHIRE: Simple Aligner for
Phrasal Paraphrase with Hierarchical Representation. In Proceedings of the 12th International Conference on Language Resources and Evaluation (LREC 2020), pp.6863–6869, 2020.
(Acceptance Rate: 60%)

42. Tomoyuki Kajiwara, Biwa Miura and Yuki Arase. Monolingual Transfer Learning via Bilingual Translators for Style-Sensitive Paraphrase Generation. In Proceedings of the ThirtyFourth AAAI Conference on Artificial Intelligence (AAAI 2020), pp.8042–8049, 2020. (Acceptance
Rate: 21%)
43. Kazuki Ashihara, Tomoyuki Kajiwara, Yuki Arase and Satoru Uchida. Contextualized context2vec. In Proceedings of the 5th Workshop on Noisy User-generated Text (W-NUT 2019),
pp.397–406, 2019. (Acceptance Rate: 65%)
44. Daiki Nishihara, Tomoyuki Kajiwara and Yuki Arase. Controllable Text Simplification with
Lexical Constraint Loss. In Proceedings of the ACL 2019 Student Research Workshop (ACL2019 SRW), pp.260–266, 2019. (Acceptance Rate: 36%)
45. Tomoyuki Kajiwara. Negative Lexically Constrained Decoding for Paraphrase Generation. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics(ACL 2019), pp.6047–6052, 2019. (Acceptance Rate: 18%)
46. Kazuki Ashihara, Tomoyuki Kajiwara, Yuki Arase and Satoru Uchida. Contextualized Word
Representations for Multi-Sense Embedding. In Proceedings of the 32nd Pacific Asia Conference on Language, Information and Computation (PACLIC 32), pp.28–36, 2018. (Acceptance
Rate: 55%)
47. Hiroki Shimanaka, Tomoyuki Kajiwara and Mamoru Komachi. Metric for Automatic Machine Translation Evaluation based on Universal Sentence Representations. In Proceedings of the NAACL 2018 Student Research Workshop (NAACL 2018 SRW), pp.106–111, 2018.
(Acceptance Rate: 39%)
48. Tomoyuki Kajiwara, Mamoru Komachi and Daichi Mochihashi. MIPA: Mutual Information
Based Paraphrase Acquisition via Bilingual Pivoting. In Proceedings of the 8th International Joint Conference on Natural Language Processing (IJCNLP 2017), pp.80–89, 2017. (Acceptance Rate: 31%)
49. Tomoyuki Kajiwara and Atsushi Fujita. Semantic Features Based on Word Alignments
for Estimating Quality of Text Simplification. In Proceedings of the 8th International Joint
Conference on Natural Language Processing (IJCNLP 2017), pp.109–115, 2017. (Acceptance Rate:
31%)
50. Yuuki Sekizawa, Tomoyuki Kajiwara and Mamoru Komachi. Improving Japanese-English
Neural Machine Translation by Paraphrasing the Target Language. In Proceedings ofthe 4th Workshop on Asian Translation (WAT 2017), pp.64–69, 2017. (Acceptance Rate: ??%)
51. Yui Suzuki, Tomoyuki Kajiwara and Mamoru Komachi. Building a Non-Trivial Paraphrase
Corpus using Multiple Machine Translation Systems. In Proceedings of the ACL 2017
Student Research Workshop (ACL 2017 SRW), pp.36–42, 2017. (Acceptance Rate: 40%)
52. Tomoyuki Kajiwara and Mamoru Komachi. Building a Monolingual Parallel Corpus for
Text Simplification Using Sentence Similarity Based on Alignment between Word
Embeddings. In Proceedings of the 26th International Conference on Computational Linguistics(COLING 2016), pp.1147–1158, 2016. (Acceptance Rate: 32%)
53. Tomonori Kodaira, Tomoyuki Kajiwara and Mamoru Komachi. Controlled and Balanced
Dataset for Japanese Lexical Simplification. In Proceedings of the ACL 2016 Student
Research Workshop (ACL 2016 SRW), pp.1–7, 2016. (Acceptance Rate: 36%)
54. Tomoyuki Kajiwara and Kazuhide Yamamoto. Evaluation Dataset and System for Japanese
Lexical Simplification. In Proceedings of the ACL-IJCNLP 2015 Student Research Workshop(ACL 2015 SRW), pp.35–40, 2015. (Acceptance Rate: 31%)

55. Tomoyuki Kajiwara and Kazuhide Yamamoto. Noun Paraphrasing Based on a Variety ofContexts. In Proceedings of the 28th Pacific Asia Conference on Language, Information andComputation (PACLIC 28), pp.644–649, 2014. (Acceptance Rate: 46%)
56. Tomoyuki Kajiwara, Hiroshi Matsumoto and Kazuhide Yamamoto. Selecting Proper Lexical
Paraphrase for Children. In Proceedings of the 25th Conference on Computational Linguistics
and Speech Processing (ROCLING 2013), pp.769–772, 2013. (Acceptance Rate: 71%)
System Description Papers
1. Yuting Zhao, Mamoru Komachi, Tomoyuki Kajiwara and Chenhui Chu. TMEKU System for
the WAT2021 Multimodal Translation Task. In Proceedings of the 8th Workshop on AsianTranslation (WAT 2021), pp.174–180, 2021.
We ranked 1st at Multimodal Translation Shared Task.
2. Akifumi Nakamachi, Hiroki Shimanaka, Tomoyuki Kajiwara and Mamoru Komachi. TMUOU
Submission for WMT20 Quality Estimation Shared Task. In Proceedings of the Fifth
Conference on Machine Translation (WMT 20), pp.1037–1041, 2020.
We ranked 4th in Pearson and 2nd in MAE/RMSE at QE Shared Task.
3. Sora Ohashi, Tomoyuki Kajiwara, Chenhui Chu, Noriko Takemura, Yuta Nakashima and Hajime
Nagahara. IDSOU at WNUT-2020 Task 2: Identification of Informative COVID-19
English Tweets. In Proceedings of the 6th Workshop on Noisy User-generated Text (W-NUT
2020), pp.428–433, 2020.
We ranked 16th out of 55 at Shared Task on Identification of Informative COVID-19 Tweets.
4. Hiroki Shimanaka, Tomoyuki Kajiwara and Mamoru Komachi. RUSE: Regressor Using Sentence Embeddings for Automatic Machine Translation Evaluation. In Proceedings of
the Third Conference on Machine Translation (WMT 18), pp.751–758, 2018.
We ranked 1st in all 7 language pairs of to-English at Metrics Shared Task.
5. Tomoyuki Kajiwara and Mamoru Komachi. Complex Word Identification Based on Frequency in a Learner Corpus. In Proceedings of the 13th Workshop on Innovative Use of NLP
for Building Educational Applications (BEA 13), pp.195–199, 2018.
We ranked 1st in 5 out of 12 tracks at Complex Word Identification Shared Task.
6. Masahiro Kaneko, Tomoyuki Kajiwara and Mamoru Komachi. TMU System for SLAM-2018.
In Proceedings of the 13th Workshop on Innovative Use of NLP for Building Educational Applications (BEA 13), pp.365–369, 2018.
We ranked 4th out of 15 at Shared Task on Second Language Acquisition Modeling.
ArXiv Papers
1. Yuto Kuroda, Atsushi Fujita, Tomoyuki Kajiwara and Takashi Ninomiya. Unsupervised Translation Quality Estimation Exploiting Synthetic Data and Pre-trained Multilingual
Encoder. arXiv:2311.05117, 2023.
2. Hiroki Shimanaka, Tomoyuki Kajiwara and Mamoru Komachi. Machine Translation Evaluation with BERT Regressor. arXiv:1907.12679, 2019.
3. Tomoyuki Kajiwara, Chihiro Tanikawa, Yuujin Shimizu, Chenhui Chu, Takashi Yamashiro andHajime Nagahara. Using Natural Language Processing to Develop an Automated Orthodontic Diagnostic System. arXiv:1905.13601, 2019.
Domestic Conference Papers

59 oral presentations and 69 poster presentations

AWARDSBest Paper Award
2019: Journal of Natural Language Processing Vol.25 (Kajiwara and Komachi)
Outstanding Paper Award
2023: Journal of Natural Language Processing Vol.29 (Takayama, Kajiwara and Arase)
Best Paper Award for Young Researcher
2021: The 83rd National Convention of IPSJ (Nishihara, Kajiwara, Tanikawa, Shimizu and Nagahara)
Outstanding Research Award
2023: The 256th IPSJ Natural Language Processing Meeting (Miyano, Kajiwara and Arase)
2016: The 229th IPSJ Natural Language Processing Meeting (Kajiwara and Komachi)
Young Researcher Award
2024: The 30th Annual Meeting of ANLP (Horiguchi, Kajiwara, Arase and Ninomiya)
2022: The 28th Annual Meeting of ANLP (Kuroda, Kajiwara, Arase and Ninomiya)
2022: The 28th Annual Meeting of ANLP (Miyauchi, Suzuki, Akiyama, Kajiwara, Ninomiya, ...)
2021: The 249th IPSJ Natural Language Processing Meeting (Takayama, Kajiwara and Arase)
2020: The 26th Annual Meeting of ANLP (Shimanaka, Kajiwara and Komachi)
2020: The 26th Annual Meeting of ANLP (Yamauchi, Kajiwara and Arase)
2019: The 241st IPSJ Natural Language Processing Meeting (Kajiwara, Miura and Arase)
Committee Special Award
2023: The 29th Annual Meeting of ANLP (Yoshimi, Kajiwara, Uchida, Arase and Ninomiya)
Encouragement Award
2023: The 22nd Forum on Information Technology (Tarumoto, Hatagaki, Miyata, Kajiwara, ...)
2023: The 18th NLP Symposium for Young Researchers (Kondo, Kajikawa, Kajiwara and Ninomiya)
2023: The 18th NLP Symposium for Young Researchers (Miyata, Koretaka, Yamauchi, Yanamoto, ...)
2022: The 21st Forum on Information Technology (Hatagaki, Kajiwara and Ninomiya)
2018: The 13th NLP Symposium for Young Researchers (Miura, Kajiwara and Arase)
2012: The 7th NLP Symposium for Young Researchers (Kajiwara and Yamamoto)Student Encouragement Award
2024: The 86th National Convention of IPSJ (Kondo, Ohtsuka, Kajiwara, Ninomiya, Hayashi, ...)
2023: The 85th National Convention of IPSJ (Tanaka, Yoshimi, Kajiwara, Uchida and Arase)
2022: The 84th National Convention of IPSJ (Honda, Masaki and Kajiwara)
2021: The 83rd National Convention of IPSJ (Nishihara, Kajiwara, Tanikawa, Shimizu and Nagahara)
2017: The 231st IPSJ Natural Language Processing Meeting (Kajiwara, Komachi and Mochihashi)
2015: The 77th National Convention of IPSJ (Kajiwara and Yamamoto)Sponsor Award
2023: The 18th NLP Symposium for Young Researchers (Miyata, Koretaka, Yamauchi, Yanamoto, ...)
2021: The 27th Annual Meeting of ANLP (Nishihara, Kajiwara, Arase and Fujita)
2019: The 14th NLP Symposium for Young Researchers (Ashihara, Kajiwara, Arase and Uchida)
2019: The 14th NLP Symposium for Young Researchers (Yamauchi, Kajiwara and Arase)
Hackathon Award
2018: The 13th NLP Symposium for Young Researchers (Matsuno, Noji, Inoue and Kajiwara)
2015: The 10th NLP Symposium for Young Researchers (Satou and Kajiwara)
Ph.D. Thesis Recommended by IPSJ SIGs
2018: Information Processing Society of Japan
Department Chair’s Award
2015: Nagaoka University of Technology