• 大学における初修中国語学習のためのブレンディッドラーニングの開発と実践（博士）＊総長賞
• 高専学生を対象とした工学・技術教育における学習動機付けに関する研究（修士）
• 初秋語学教育のためのブレンディッドラーニングにおける復習放棄者の早期検出手法に関する研究（修士）
• 電子黒板システムの教示記録と授業映像による授業振り返り支援手法に関する研究（修士）
• IMPRESSIONのための授業計画に基づく教材データ管理手法に関する研究（修士）
• 主話者と聴衆者との対話を考慮した話者発話区間検出によるシーン選択視聴支援に関する研究（修士）
  など

論文

• 田中ゆみ，三石大，大河雄一，本郷哲，“自由記述のばらつきを考慮した学習場面ラベルによる高専学生の学習意識の定量化の試み,” 教育システム情報学会誌 Vol. 39, No. 2, pp. 309-314, Apr., (2022).
• 趙秀敏，冨田昇，今野文子，大河雄一，三石大，“大学初修中国語フ゛レンテ゛ィット゛ラーニンク゛のためのスマートフォン利用復習教材「KoToToMo」の開発と実践,” 教育システム情報学会誌, Vol.36, No.2, pp. 131-142, Apr., (2019).
• 趙秀敏，冨田昇，今野文子，朱嘉琪，稲垣忠，大河雄一，三石大，“基於教學設計理論的日本首次出版的大學初級華語 Blended Learning 教材的開發和實踐,” 華語學刊, 台灣華語文教學學會, No.2, Vol.19, pp. 23-40, Dec., (2015). (in Chinese)
• Seong-Jun Hahm, Yuichi Ohkawa, Masashi Ito, Motoyuki Suzuki, Akinori Ito and Shozo Makino, “Speech Recognition under Multiple Noise Environment Based on Multi-Mixture HMM and Weight Optimization by the Aspect Model,” IEICE Trans. on information and systems, Vol.E93-D, No.7, pp. 2407-2416, Jul., (2010).
• Yuichi Ohkawa, Motoyuki Suzuki, Hirokazu Ogasawara, Akinori Ito and Shozo Makino, “A Speaker Adaptation Method for Non-native Speech Using Learners' Native Utterances for Computer-Assisted Language Learning Systems,” Speech Communication, Vol.51, No.10, pp. 874-881, Oct., (2009).
• 大河雄一, 伊藤彰則, 鈴木基之, 牧野正三, “発話速度と言語的特徴による変動を考慮した音素持続時間モデルを用いた音声認識”, 情報処理学会論文誌, pp. 3380-3391, Vol.47, No.12, Dec., (2006).

国際会議

• Ryo Nakagawa, Yuichi Ohkawa, Xiumin Zhao, Akiko Takahashi, Tomoya Ohyama, Takashi Mitsuishi and Yoshinori Hayakawa, “Implementation of UX Design to Enhance Spontaneous and Continuous Study of a Mobile Application for Foreign Language Learning,” Proceedings of EdMedia + Innovate Learning 2022, pp. 1119-1123, Jun., (2022).
• Zahra Azizah, Takashi Mitsuishi, Yuichi Ohkawa, Xiumin Zhao, Tomoya Ohyama, and Yoshinori Hayakawa, “Understanding the Relationship between Learning Motivation and Academic Performance in Mobile Language Learning,” Companion Proceedings of the 12th International Conference on Learning Analytics & Knowledge (LAK22), pp. 89-91, Mar., (2022).
• Jarmo Seppala, Takashi Mitsuishi, Yuichi Ohkawa, Xiumin Zhao and Marko Nieminen, “Study on UX design in enhancing student motivations in mobile language learning,” 2020 IEEE International Conference on Teaching, Assessment, and Learning for Engineering (TALE), pp. 948-951, Dec., (2020).
• Yuichi Ohkawa, Masaaki Kodama, Yuta Konno, Xiumin Zhao, and Takashi Mitsuishi, “Development and Evaluation of Smartphone Learning Material for Blended Language Learning,” Proceedings of 2019 4th International Conference on Information Technology (InCIT), pp. 108-113, Oct., (2019).
• Yuichi Ohkawa, Masaaki Kodama, Yuta Konno, Xiumin Zhao and Takashi Mitsuishi, “A Study on UI Design of Smartphone App for Continuous Blended Language Learning,” Proceedings of 2018 5th International Conference on Business and Industrial Research (ICBIR), pp. 584-589, May, (2018).
• 趙 秀敏, 冨田 昇, 大河雄一, 三石 大，“基於教學設計理論的日本大學初級華語Blended Learning的開發－利用智能手機的復習教材《KOTOTOMO》的設計手法及其教學實踐－,” 第十六屆台灣華語文教學年會?國際學術研討會論文集, pp. 26-37, Dec., (2017). (in Chinese)
• Yuichi OHKAWA, Kazuki WATANABE, Takashi MITSUISHI, “A Shareable Whiteboard System for Distance Collaborative Learning which Enables Instruction for Multiple Groups of Students,” Main Conference Proceedings of the 22nd International Conference on Computers in Education (ICCE 2014), pp. 141-150, Dec., (2014).
• Masateru HISHINA, Katsuaki MIIKE, Nobutake ASABA, Satoru MURAKAMI, Yuichi OHKAWA and Takashi Mitsuishi, “Study on Effects of Text Decoration for a Text Based Communication Tool in Education,” HCII 2013, LNCS 8004, pp. 565-574, Jul., (2013).
• Yuichi Ohkawa and Takashi Mitsuishi, “A Development of Web-Based Player for Instructions Recorded with the Electronic Blackboard System IMPRESSION,” HUMAN-COMPUTER INTERACTION, Part IV, HCII 2011, LNCS 6764, pp. 500 - 509, Jul., (2011).
• Fumiko Konno, Yuka Kanno, Yuichi Ohkawa, Takashi Mitsuishi and Koji Hashimoto, “Design and Implementation of a Teacher Reflection Support System using IMPRESSION and MidField,” Proc. of ED-MEDIA 2009, pp. 2421 - 2430, Jul., (2009).
• Yuichi OHKAWA, Akihiro YOSHIDA, Motoyuki SUZUKI, Akinori ITO and Shozo MAKINO, “An Optimized Multi-duration HMM for Spontaneous Speech Recognition”, Proceedings of the 8th European Conference on Speech Communication and Technology (EUROSPEECH 2003)., pp.485-488, Sep., (2003).
• Yuichi Ohkawa, Teruhiko Maeda, Motoyuki Suzuki and Shozo Makino, “Automatic Phoneme Labeling System Using Adaptation Methods”, Second International Workshop on East-Asian Language Resources and Evaluation (Oriental COCOSDA '99)., pp. 93-96, May (1999).